layers: Move shader validation plumbing out into own file

7 files changed, 1657 insertions, 1574 deletions

diff --git a/build-android/cmake/layerlib/CMakeLists.txt b/build-android/cmake/layerlib/CMakeLists.txt
index f7c27e82..c8455c81 100644
--- a/build-android/cmake/layerlib/CMakeLists.txt
+++ b/build-android/cmake/layerlib/CMakeLists.txt
@@ -64,6 +64,7 @@ add_library(VkLayer_core_validation SHARED
         ${SRC_DIR}/layers/core_validation.cpp
         ${SRC_DIR}/layers/descriptor_sets.cpp
         ${SRC_DIR}/layers/buffer_validation.cpp
+        ${SRC_DIR}/layers/shader_validation.cpp
         ${SRC_DIR}/layers/vk_layer_table.cpp)
 target_include_directories(VkLayer_core_validation PRIVATE
         ${SRC_DIR}/include
diff --git a/build-android/jni/Android.mk b/build-android/jni/Android.mk
index 290bb121..cd0d6068 100644
--- a/build-android/jni/Android.mk
+++ b/build-android/jni/Android.mk
@@ -36,6 +36,7 @@ LOCAL_MODULE := VkLayer_core_validation
 LOCAL_SRC_FILES += $(SRC_DIR)/layers/core_validation.cpp
 LOCAL_SRC_FILES += $(SRC_DIR)/layers/descriptor_sets.cpp
 LOCAL_SRC_FILES += $(SRC_DIR)/layers/buffer_validation.cpp
+LOCAL_SRC_FILES += $(SRC_DIR)/layers/shader_validation.cpp
 LOCAL_SRC_FILES += $(SRC_DIR)/layers/vk_layer_table.cpp
 LOCAL_C_INCLUDES += $(SRC_DIR)/include \
                     $(SRC_DIR)/layers \
diff --git a/layers/CMakeLists.txt b/layers/CMakeLists.txt
index d26d3997..6e254ff9 100644
--- a/layers/CMakeLists.txt
+++ b/layers/CMakeLists.txt
@@ -168,7 +168,7 @@ else()
 endif()
 add_dependencies(VkLayer_utils generate_helper_files)
 
-add_vk_layer(core_validation core_validation.cpp vk_layer_table.cpp descriptor_sets.cpp buffer_validation.cpp)
+add_vk_layer(core_validation core_validation.cpp vk_layer_table.cpp descriptor_sets.cpp buffer_validation.cpp shader_validation.cpp)
 add_vk_layer(object_tracker object_tracker.cpp vk_layer_table.cpp)
 add_vk_layer(swapchain swapchain.cpp vk_layer_table.cpp)
 # generated
diff --git a/layers/core_validation.cpp b/layers/core_validation.cpp
index 7e14b502..23f9e8c7 100644
--- a/layers/core_validation.cpp
+++ b/layers/core_validation.cpp
@@ -64,6 +64,7 @@
 #endif
 #include "core_validation.h"
 #include "buffer_validation.h"
+#include "shader_validation.h"
 #include "vk_layer_table.h"
 #include "vk_layer_data.h"
 #include "vk_layer_extension_utils.h"
@@ -117,9 +118,6 @@ static const VkDeviceMemory MEMORY_UNBOUND = VkDeviceMemory(~((uint64_t)(0)) - 1
 // by the extent of a swapchain targeting the surface.
 static const uint32_t kSurfaceSizeFromSwapchain = 0xFFFFFFFFu;
 
-// fwd decls
-struct shader_module;
-
 struct instance_layer_data {
     VkInstance instance = VK_NULL_HANDLE;
     debug_report_data *report_data = nullptr;
@@ -208,87 +206,6 @@ void ValidateLayerOrdering(const TCreateInfo &createInfo) {
     }
 }
 
-// Code imported from shader_checker
-static void build_def_index(shader_module *);
-
-// A forward iterator over spirv instructions. Provides easy access to len, opcode, and content words
-// without the caller needing to care too much about the physical SPIRV module layout.
-struct spirv_inst_iter {
-    std::vector<uint32_t>::const_iterator zero;
-    std::vector<uint32_t>::const_iterator it;
-
-    uint32_t len() {
-        auto result = *it >> 16;
-        assert(result > 0);
-        return result;
-    }
-
-    uint32_t opcode() { return *it & 0x0ffffu; }
-
-    uint32_t const &word(unsigned n) {
-        assert(n < len());
-        return it[n];
-    }
-
-    uint32_t offset() { return (uint32_t)(it - zero); }
-
-    spirv_inst_iter() {}
-
-    spirv_inst_iter(std::vector<uint32_t>::const_iterator zero, std::vector<uint32_t>::const_iterator it) : zero(zero), it(it) {}
-
-    bool operator==(spirv_inst_iter const &other) { return it == other.it; }
-
-    bool operator!=(spirv_inst_iter const &other) { return it != other.it; }
-
-    spirv_inst_iter operator++(int) {  // x++
-        spirv_inst_iter ii = *this;
-        it += len();
-        return ii;
-    }
-
-    spirv_inst_iter operator++() {  // ++x;
-        it += len();
-        return *this;
-    }
-
-    // The iterator and the value are the same thing.
-    spirv_inst_iter &operator*() { return *this; }
-    spirv_inst_iter const &operator*() const { return *this; }
-};
-
-struct shader_module {
-    // The spirv image itself
-    vector<uint32_t> words;
-    // A mapping of <id> to the first word of its def. this is useful because walking type
-    // trees, constant expressions, etc requires jumping all over the instruction stream.
-    unordered_map<unsigned, unsigned> def_index;
-    bool has_valid_spirv;
-
-    shader_module(VkShaderModuleCreateInfo const *pCreateInfo)
-        : words((uint32_t *)pCreateInfo->pCode, (uint32_t *)pCreateInfo->pCode + pCreateInfo->codeSize / sizeof(uint32_t)),
-          def_index(),
-          has_valid_spirv(true) {
-        build_def_index(this);
-    }
-
-    shader_module() : has_valid_spirv(false) {}
-
-    // Expose begin() / end() to enable range-based for
-    spirv_inst_iter begin() const { return spirv_inst_iter(words.begin(), words.begin() + 5); }  // First insn
-    spirv_inst_iter end() const { return spirv_inst_iter(words.begin(), words.end()); }          // Just past last insn
-    // Given an offset into the module, produce an iterator there.
-    spirv_inst_iter at(unsigned offset) const { return spirv_inst_iter(words.begin(), words.begin() + offset); }
-
-    // Gets an iterator to the definition of an id
-    spirv_inst_iter get_def(unsigned id) const {
-        auto it = def_index.find(id);
-        if (it == def_index.end()) {
-            return end();
-        }
-        return at(it->second);
-    }
-};
-
 // TODO : This can be much smarter, using separate locks for separate global data
 static std::mutex global_lock;
 
@@ -405,6 +322,10 @@ SURFACE_STATE *GetSurfaceState(instance_layer_data *instance_data, VkSurfaceKHR
     return &it->second;
 }
 
+DeviceExtensions const *GetEnabledExtensions(layer_data const *dev_data) {
+    return &dev_data->extensions;
+}
+
 // Return ptr to memory binding for given handle of specified type
 static BINDABLE *GetObjectMemBinding(layer_data *dev_data, uint64_t handle, VulkanObjectType type) {
     switch (type) {
@@ -755,1054 +676,6 @@ static bool SetSparseMemBinding(layer_data *dev_data, MEM_BINDING binding, uint6
     return skip;
 }
 
-// SPIRV utility functions
-static void build_def_index(shader_module *module) {
-    for (auto insn : *module) {
-        switch (insn.opcode()) {
-            // Types
-            case spv::OpTypeVoid:
-            case spv::OpTypeBool:
-            case spv::OpTypeInt:
-            case spv::OpTypeFloat:
-            case spv::OpTypeVector:
-            case spv::OpTypeMatrix:
-            case spv::OpTypeImage:
-            case spv::OpTypeSampler:
-            case spv::OpTypeSampledImage:
-            case spv::OpTypeArray:
-            case spv::OpTypeRuntimeArray:
-            case spv::OpTypeStruct:
-            case spv::OpTypeOpaque:
-            case spv::OpTypePointer:
-            case spv::OpTypeFunction:
-            case spv::OpTypeEvent:
-            case spv::OpTypeDeviceEvent:
-            case spv::OpTypeReserveId:
-            case spv::OpTypeQueue:
-            case spv::OpTypePipe:
-                module->def_index[insn.word(1)] = insn.offset();
-                break;
-
-            // Fixed constants
-            case spv::OpConstantTrue:
-            case spv::OpConstantFalse:
-            case spv::OpConstant:
-            case spv::OpConstantComposite:
-            case spv::OpConstantSampler:
-            case spv::OpConstantNull:
-                module->def_index[insn.word(2)] = insn.offset();
-                break;
-
-            // Specialization constants
-            case spv::OpSpecConstantTrue:
-            case spv::OpSpecConstantFalse:
-            case spv::OpSpecConstant:
-            case spv::OpSpecConstantComposite:
-            case spv::OpSpecConstantOp:
-                module->def_index[insn.word(2)] = insn.offset();
-                break;
-
-            // Variables
-            case spv::OpVariable:
-                module->def_index[insn.word(2)] = insn.offset();
-                break;
-
-            // Functions
-            case spv::OpFunction:
-                module->def_index[insn.word(2)] = insn.offset();
-                break;
-
-            default:
-                // We don't care about any other defs for now.
-                break;
-        }
-    }
-}
-
-static spirv_inst_iter find_entrypoint(shader_module *src, char const *name, VkShaderStageFlagBits stageBits) {
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpEntryPoint) {
-            auto entrypointName = (char const *)&insn.word(3);
-            auto entrypointStageBits = 1u << insn.word(1);
-
-            if (!strcmp(entrypointName, name) && (entrypointStageBits & stageBits)) {
-                return insn;
-            }
-        }
-    }
-
-    return src->end();
-}
-
-static char const *storage_class_name(unsigned sc) {
-    switch (sc) {
-        case spv::StorageClassInput:
-            return "input";
-        case spv::StorageClassOutput:
-            return "output";
-        case spv::StorageClassUniformConstant:
-            return "const uniform";
-        case spv::StorageClassUniform:
-            return "uniform";
-        case spv::StorageClassWorkgroup:
-            return "workgroup local";
-        case spv::StorageClassCrossWorkgroup:
-            return "workgroup global";
-        case spv::StorageClassPrivate:
-            return "private global";
-        case spv::StorageClassFunction:
-            return "function";
-        case spv::StorageClassGeneric:
-            return "generic";
-        case spv::StorageClassAtomicCounter:
-            return "atomic counter";
-        case spv::StorageClassImage:
-            return "image";
-        case spv::StorageClassPushConstant:
-            return "push constant";
-        default:
-            return "unknown";
-    }
-}
-
-// Get the value of an integral constant
-unsigned get_constant_value(shader_module const *src, unsigned id) {
-    auto value = src->get_def(id);
-    assert(value != src->end());
-
-    if (value.opcode() != spv::OpConstant) {
-        // TODO: Either ensure that the specialization transform is already performed on a module we're
-        //       considering here, OR -- specialize on the fly now.
-        return 1;
-    }
-
-    return value.word(3);
-}
-
-static void describe_type_inner(std::ostringstream &ss, shader_module const *src, unsigned type) {
-    auto insn = src->get_def(type);
-    assert(insn != src->end());
-
-    switch (insn.opcode()) {
-        case spv::OpTypeBool:
-            ss << "bool";
-            break;
-        case spv::OpTypeInt:
-            ss << (insn.word(3) ? 's' : 'u') << "int" << insn.word(2);
-            break;
-        case spv::OpTypeFloat:
-            ss << "float" << insn.word(2);
-            break;
-        case spv::OpTypeVector:
-            ss << "vec" << insn.word(3) << " of ";
-            describe_type_inner(ss, src, insn.word(2));
-            break;
-        case spv::OpTypeMatrix:
-            ss << "mat" << insn.word(3) << " of ";
-            describe_type_inner(ss, src, insn.word(2));
-            break;
-        case spv::OpTypeArray:
-            ss << "arr[" << get_constant_value(src, insn.word(3)) << "] of ";
-            describe_type_inner(ss, src, insn.word(2));
-            break;
-        case spv::OpTypePointer:
-            ss << "ptr to " << storage_class_name(insn.word(2)) << " ";
-            describe_type_inner(ss, src, insn.word(3));
-            break;
-        case spv::OpTypeStruct: {
-            ss << "struct of (";
-            for (unsigned i = 2; i < insn.len(); i++) {
-                describe_type_inner(ss, src, insn.word(i));
-                if (i == insn.len() - 1) {
-                    ss << ")";
-                } else {
-                    ss << ", ";
-                }
-            }
-            break;
-        }
-        case spv::OpTypeSampler:
-            ss << "sampler";
-            break;
-        case spv::OpTypeSampledImage:
-            ss << "sampler+";
-            describe_type_inner(ss, src, insn.word(2));
-            break;
-        case spv::OpTypeImage:
-            ss << "image(dim=" << insn.word(3) << ", sampled=" << insn.word(7) << ")";
-            break;
-        default:
-            ss << "oddtype";
-            break;
-    }
-}
-
-static std::string describe_type(shader_module const *src, unsigned type) {
-    std::ostringstream ss;
-    describe_type_inner(ss, src, type);
-    return ss.str();
-}
-
-static bool is_narrow_numeric_type(spirv_inst_iter type) {
-    if (type.opcode() != spv::OpTypeInt && type.opcode() != spv::OpTypeFloat) return false;
-    return type.word(2) < 64;
-}
-
-static bool types_match(shader_module const *a, shader_module const *b, unsigned a_type, unsigned b_type, bool a_arrayed,
-                        bool b_arrayed, bool relaxed) {
-    // Walk two type trees together, and complain about differences
-    auto a_insn = a->get_def(a_type);
-    auto b_insn = b->get_def(b_type);
-    assert(a_insn != a->end());
-    assert(b_insn != b->end());
-
-    if (a_arrayed && a_insn.opcode() == spv::OpTypeArray) {
-        return types_match(a, b, a_insn.word(2), b_type, false, b_arrayed, relaxed);
-    }
-
-    if (b_arrayed && b_insn.opcode() == spv::OpTypeArray) {
-        // We probably just found the extra level of arrayness in b_type: compare the type inside it to a_type
-        return types_match(a, b, a_type, b_insn.word(2), a_arrayed, false, relaxed);
-    }
-
-    if (a_insn.opcode() == spv::OpTypeVector && relaxed && is_narrow_numeric_type(b_insn)) {
-        return types_match(a, b, a_insn.word(2), b_type, a_arrayed, b_arrayed, false);
-    }
-
-    if (a_insn.opcode() != b_insn.opcode()) {
-        return false;
-    }
-
-    if (a_insn.opcode() == spv::OpTypePointer) {
-        // Match on pointee type. storage class is expected to differ
-        return types_match(a, b, a_insn.word(3), b_insn.word(3), a_arrayed, b_arrayed, relaxed);
-    }
-
-    if (a_arrayed || b_arrayed) {
-        // If we havent resolved array-of-verts by here, we're not going to.
-        return false;
-    }
-
-    switch (a_insn.opcode()) {
-        case spv::OpTypeBool:
-            return true;
-        case spv::OpTypeInt:
-            // Match on width, signedness
-            return a_insn.word(2) == b_insn.word(2) && a_insn.word(3) == b_insn.word(3);
-        case spv::OpTypeFloat:
-            // Match on width
-            return a_insn.word(2) == b_insn.word(2);
-        case spv::OpTypeVector:
-            // Match on element type, count.
-            if (!types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false)) return false;
-            if (relaxed && is_narrow_numeric_type(a->get_def(a_insn.word(2)))) {
-                return a_insn.word(3) >= b_insn.word(3);
-            } else {
-                return a_insn.word(3) == b_insn.word(3);
-            }
-        case spv::OpTypeMatrix:
-            // Match on element type, count.
-            return types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false) &&
-                   a_insn.word(3) == b_insn.word(3);
-        case spv::OpTypeArray:
-            // Match on element type, count. these all have the same layout. we don't get here if b_arrayed. This differs from
-            // vector & matrix types in that the array size is the id of a constant instruction, * not a literal within OpTypeArray
-            return types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false) &&
-                   get_constant_value(a, a_insn.word(3)) == get_constant_value(b, b_insn.word(3));
-        case spv::OpTypeStruct:
-            // Match on all element types
-            {
-                if (a_insn.len() != b_insn.len()) {
-                    return false;  // Structs cannot match if member counts differ
-                }
-
-                for (unsigned i = 2; i < a_insn.len(); i++) {
-                    if (!types_match(a, b, a_insn.word(i), b_insn.word(i), a_arrayed, b_arrayed, false)) {
-                        return false;
-                    }
-                }
-
-                return true;
-            }
-        default:
-            // Remaining types are CLisms, or may not appear in the interfaces we are interested in. Just claim no match.
-            return false;
-    }
-}
-
-static unsigned value_or_default(std::unordered_map<unsigned, unsigned> const &map, unsigned id, unsigned def) {
-    auto it = map.find(id);
-    if (it == map.end())
-        return def;
-    else
-        return it->second;
-}
-
-static unsigned get_locations_consumed_by_type(shader_module const *src, unsigned type, bool strip_array_level) {
-    auto insn = src->get_def(type);
-    assert(insn != src->end());
-
-    switch (insn.opcode()) {
-        case spv::OpTypePointer:
-            // See through the ptr -- this is only ever at the toplevel for graphics shaders we're never actually passing
-            // pointers around.
-            return get_locations_consumed_by_type(src, insn.word(3), strip_array_level);
-        case spv::OpTypeArray:
-            if (strip_array_level) {
-                return get_locations_consumed_by_type(src, insn.word(2), false);
-            } else {
-                return get_constant_value(src, insn.word(3)) * get_locations_consumed_by_type(src, insn.word(2), false);
-            }
-        case spv::OpTypeMatrix:
-            // Num locations is the dimension * element size
-            return insn.word(3) * get_locations_consumed_by_type(src, insn.word(2), false);
-        case spv::OpTypeVector: {
-            auto scalar_type = src->get_def(insn.word(2));
-            auto bit_width =
-                (scalar_type.opcode() == spv::OpTypeInt || scalar_type.opcode() == spv::OpTypeFloat) ? scalar_type.word(2) : 32;
-
-            // Locations are 128-bit wide; 3- and 4-component vectors of 64 bit types require two.
-            return (bit_width * insn.word(3) + 127) / 128;
-        }
-        default:
-            // Everything else is just 1.
-            return 1;
-
-            // TODO: extend to handle 64bit scalar types, whose vectors may need multiple locations.
-    }
-}
-
-static unsigned get_locations_consumed_by_format(VkFormat format) {
-    switch (format) {
-        case VK_FORMAT_R64G64B64A64_SFLOAT:
-        case VK_FORMAT_R64G64B64A64_SINT:
-        case VK_FORMAT_R64G64B64A64_UINT:
-        case VK_FORMAT_R64G64B64_SFLOAT:
-        case VK_FORMAT_R64G64B64_SINT:
-        case VK_FORMAT_R64G64B64_UINT:
-            return 2;
-        default:
-            return 1;
-    }
-}
-
-typedef std::pair<unsigned, unsigned> location_t;
-typedef std::pair<unsigned, unsigned> descriptor_slot_t;
-
-struct interface_var {
-    uint32_t id;
-    uint32_t type_id;
-    uint32_t offset;
-    bool is_patch;
-    bool is_block_member;
-    bool is_relaxed_precision;
-    // TODO: collect the name, too? Isn't required to be present.
-};
-
-struct shader_stage_attributes {
-    char const *const name;
-    bool arrayed_input;
-    bool arrayed_output;
-};
-
-static shader_stage_attributes shader_stage_attribs[] = {
-    {"vertex shader", false, false},  {"tessellation control shader", true, true}, {"tessellation evaluation shader", true, false},
-    {"geometry shader", true, false}, {"fragment shader", false, false},
-};
-
-static spirv_inst_iter get_struct_type(shader_module const *src, spirv_inst_iter def, bool is_array_of_verts) {
-    while (true) {
-        if (def.opcode() == spv::OpTypePointer) {
-            def = src->get_def(def.word(3));
-        } else if (def.opcode() == spv::OpTypeArray && is_array_of_verts) {
-            def = src->get_def(def.word(2));
-            is_array_of_verts = false;
-        } else if (def.opcode() == spv::OpTypeStruct) {
-            return def;
-        } else {
-            return src->end();
-        }
-    }
-}
-
-static void collect_interface_block_members(shader_module const *src, std::map<location_t, interface_var> *out,
-                                            std::unordered_map<unsigned, unsigned> const &blocks, bool is_array_of_verts,
-                                            uint32_t id, uint32_t type_id, bool is_patch) {
-    // Walk down the type_id presented, trying to determine whether it's actually an interface block.
-    auto type = get_struct_type(src, src->get_def(type_id), is_array_of_verts && !is_patch);
-    if (type == src->end() || blocks.find(type.word(1)) == blocks.end()) {
-        // This isn't an interface block.
-        return;
-    }
-
-    std::unordered_map<unsigned, unsigned> member_components;
-    std::unordered_map<unsigned, unsigned> member_relaxed_precision;
-
-    // Walk all the OpMemberDecorate for type's result id -- first pass, collect components.
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
-            unsigned member_index = insn.word(2);
-
-            if (insn.word(3) == spv::DecorationComponent) {
-                unsigned component = insn.word(4);
-                member_components[member_index] = component;
-            }
-
-            if (insn.word(3) == spv::DecorationRelaxedPrecision) {
-                member_relaxed_precision[member_index] = 1;
-            }
-        }
-    }
-
-    // Second pass -- produce the output, from Location decorations
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
-            unsigned member_index = insn.word(2);
-            unsigned member_type_id = type.word(2 + member_index);
-
-            if (insn.word(3) == spv::DecorationLocation) {
-                unsigned location = insn.word(4);
-                unsigned num_locations = get_locations_consumed_by_type(src, member_type_id, false);
-                auto component_it = member_components.find(member_index);
-                unsigned component = component_it == member_components.end() ? 0 : component_it->second;
-                bool is_relaxed_precision = member_relaxed_precision.find(member_index) != member_relaxed_precision.end();
-
-                for (unsigned int offset = 0; offset < num_locations; offset++) {
-                    interface_var v = {};
-                    v.id = id;
-                    // TODO: member index in interface_var too?
-                    v.type_id = member_type_id;
-                    v.offset = offset;
-                    v.is_patch = is_patch;
-                    v.is_block_member = true;
-                    v.is_relaxed_precision = is_relaxed_precision;
-                    (*out)[std::make_pair(location + offset, component)] = v;
-                }
-            }
-        }
-    }
-}
-
-static std::map<location_t, interface_var> collect_interface_by_location(shader_module const *src, spirv_inst_iter entrypoint,
-                                                                         spv::StorageClass sinterface, bool is_array_of_verts) {
-    std::unordered_map<unsigned, unsigned> var_locations;
-    std::unordered_map<unsigned, unsigned> var_builtins;
-    std::unordered_map<unsigned, unsigned> var_components;
-    std::unordered_map<unsigned, unsigned> blocks;
-    std::unordered_map<unsigned, unsigned> var_patch;
-    std::unordered_map<unsigned, unsigned> var_relaxed_precision;
-
-    for (auto insn : *src) {
-        // We consider two interface models: SSO rendezvous-by-location, and builtins. Complain about anything that
-        // fits neither model.
-        if (insn.opcode() == spv::OpDecorate) {
-            if (insn.word(2) == spv::DecorationLocation) {
-                var_locations[insn.word(1)] = insn.word(3);
-            }
-
-            if (insn.word(2) == spv::DecorationBuiltIn) {
-                var_builtins[insn.word(1)] = insn.word(3);
-            }
-
-            if (insn.word(2) == spv::DecorationComponent) {
-                var_components[insn.word(1)] = insn.word(3);
-            }
-
-            if (insn.word(2) == spv::DecorationBlock) {
-                blocks[insn.word(1)] = 1;
-            }
-
-            if (insn.word(2) == spv::DecorationPatch) {
-                var_patch[insn.word(1)] = 1;
-            }
-
-            if (insn.word(2) == spv::DecorationRelaxedPrecision) {
-                var_relaxed_precision[insn.word(1)] = 1;
-            }
-        }
-    }
-
-    // TODO: handle grouped decorations
-    // TODO: handle index=1 dual source outputs from FS -- two vars will have the same location, and we DON'T want to clobber.
-
-    // Find the end of the entrypoint's name string. additional zero bytes follow the actual null terminator, to fill out the
-    // rest of the word - so we only need to look at the last byte in the word to determine which word contains the terminator.
-    uint32_t word = 3;
-    while (entrypoint.word(word) & 0xff000000u) {
-        ++word;
-    }
-    ++word;
-
-    std::map<location_t, interface_var> out;
-
-    for (; word < entrypoint.len(); word++) {
-        auto insn = src->get_def(entrypoint.word(word));
-        assert(insn != src->end());
-        assert(insn.opcode() == spv::OpVariable);
-
-        if (insn.word(3) == static_cast<uint32_t>(sinterface)) {
-            unsigned id = insn.word(2);
-            unsigned type = insn.word(1);
-
-            int location = value_or_default(var_locations, id, -1);
-            int builtin = value_or_default(var_builtins, id, -1);
-            unsigned component = value_or_default(var_components, id, 0);  // Unspecified is OK, is 0
-            bool is_patch = var_patch.find(id) != var_patch.end();
-            bool is_relaxed_precision = var_relaxed_precision.find(id) != var_relaxed_precision.end();
-
-            // All variables and interface block members in the Input or Output storage classes must be decorated with either
-            // a builtin or an explicit location.
-            //
-            // TODO: integrate the interface block support here. For now, don't complain -- a valid SPIRV module will only hit
-            // this path for the interface block case, as the individual members of the type are decorated, rather than
-            // variable declarations.
-
-            if (location != -1) {
-                // A user-defined interface variable, with a location. Where a variable occupied multiple locations, emit
-                // one result for each.
-                unsigned num_locations = get_locations_consumed_by_type(src, type, is_array_of_verts && !is_patch);
-                for (unsigned int offset = 0; offset < num_locations; offset++) {
-                    interface_var v = {};
-                    v.id = id;
-                    v.type_id = type;
-                    v.offset = offset;
-                    v.is_patch = is_patch;
-                    v.is_relaxed_precision = is_relaxed_precision;
-                    out[std::make_pair(location + offset, component)] = v;
-                }
-            } else if (builtin == -1) {
-                // An interface block instance
-                collect_interface_block_members(src, &out, blocks, is_array_of_verts, id, type, is_patch);
-            }
-        }
-    }
-
-    return out;
-}
-
-static vector<std::pair<uint32_t, interface_var>> collect_interface_by_input_attachment_index(
-    shader_module const *src, std::unordered_set<uint32_t> const &accessible_ids) {
-    std::vector<std::pair<uint32_t, interface_var>> out;
-
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpDecorate) {
-            if (insn.word(2) == spv::DecorationInputAttachmentIndex) {
-                auto attachment_index = insn.word(3);
-                auto id = insn.word(1);
-
-                if (accessible_ids.count(id)) {
-                    auto def = src->get_def(id);
-                    assert(def != src->end());
-
-                    if (def.opcode() == spv::OpVariable && insn.word(3) == spv::StorageClassUniformConstant) {
-                        auto num_locations = get_locations_consumed_by_type(src, def.word(1), false);
-                        for (unsigned int offset = 0; offset < num_locations; offset++) {
-                            interface_var v = {};
-                            v.id = id;
-                            v.type_id = def.word(1);
-                            v.offset = offset;
-                            out.emplace_back(attachment_index + offset, v);
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    return out;
-}
-
-static std::vector<std::pair<descriptor_slot_t, interface_var>> collect_interface_by_descriptor_slot(
-    debug_report_data *report_data, shader_module const *src, std::unordered_set<uint32_t> const &accessible_ids) {
-    std::unordered_map<unsigned, unsigned> var_sets;
-    std::unordered_map<unsigned, unsigned> var_bindings;
-
-    for (auto insn : *src) {
-        // All variables in the Uniform or UniformConstant storage classes are required to be decorated with both
-        // DecorationDescriptorSet and DecorationBinding.
-        if (insn.opcode() == spv::OpDecorate) {
-            if (insn.word(2) == spv::DecorationDescriptorSet) {
-                var_sets[insn.word(1)] = insn.word(3);
-            }
-
-            if (insn.word(2) == spv::DecorationBinding) {
-                var_bindings[insn.word(1)] = insn.word(3);
-            }
-        }
-    }
-
-    std::vector<std::pair<descriptor_slot_t, interface_var>> out;
-
-    for (auto id : accessible_ids) {
-        auto insn = src->get_def(id);
-        assert(insn != src->end());
-
-        if (insn.opcode() == spv::OpVariable &&
-            (insn.word(3) == spv::StorageClassUniform || insn.word(3) == spv::StorageClassUniformConstant)) {
-            unsigned set = value_or_default(var_sets, insn.word(2), 0);
-            unsigned binding = value_or_default(var_bindings, insn.word(2), 0);
-
-            interface_var v = {};
-            v.id = insn.word(2);
-            v.type_id = insn.word(1);
-            out.emplace_back(std::make_pair(set, binding), v);
-        }
-    }
-
-    return out;
-}
-
-static bool validate_interface_between_stages(debug_report_data *report_data, shader_module const *producer,
-                                              spirv_inst_iter producer_entrypoint, shader_stage_attributes const *producer_stage,
-                                              shader_module const *consumer, spirv_inst_iter consumer_entrypoint,
-                                              shader_stage_attributes const *consumer_stage) {
-    bool skip = false;
-
-    auto outputs =
-        collect_interface_by_location(producer, producer_entrypoint, spv::StorageClassOutput, producer_stage->arrayed_output);
-    auto inputs =
-        collect_interface_by_location(consumer, consumer_entrypoint, spv::StorageClassInput, consumer_stage->arrayed_input);
-
-    auto a_it = outputs.begin();
-    auto b_it = inputs.begin();
-
-    // Maps sorted by key (location); walk them together to find mismatches
-    while ((outputs.size() > 0 && a_it != outputs.end()) || (inputs.size() && b_it != inputs.end())) {
-        bool a_at_end = outputs.size() == 0 || a_it == outputs.end();
-        bool b_at_end = inputs.size() == 0 || b_it == inputs.end();
-        auto a_first = a_at_end ? std::make_pair(0u, 0u) : a_it->first;
-        auto b_first = b_at_end ? std::make_pair(0u, 0u) : b_it->first;
-
-        if (b_at_end || ((!a_at_end) && (a_first < b_first))) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
-                            __LINE__, SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
-                            "%s writes to output location %u.%u which is not consumed by %s", producer_stage->name, a_first.first,
-                            a_first.second, consumer_stage->name);
-            a_it++;
-        } else if (a_at_end || a_first > b_first) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "%s consumes input location %u.%u which is not written by %s",
-                            consumer_stage->name, b_first.first, b_first.second, producer_stage->name);
-            b_it++;
-        } else {
-            // subtleties of arrayed interfaces:
-            // - if is_patch, then the member is not arrayed, even though the interface may be.
-            // - if is_block_member, then the extra array level of an arrayed interface is not
-            //   expressed in the member type -- it's expressed in the block type.
-            if (!types_match(producer, consumer, a_it->second.type_id, b_it->second.type_id,
-                             producer_stage->arrayed_output && !a_it->second.is_patch && !a_it->second.is_block_member,
-                             consumer_stage->arrayed_input && !b_it->second.is_patch && !b_it->second.is_block_member, true)) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC", "Type mismatch on location %u.%u: '%s' vs '%s'",
-                                a_first.first, a_first.second, describe_type(producer, a_it->second.type_id).c_str(),
-                                describe_type(consumer, b_it->second.type_id).c_str());
-            }
-            if (a_it->second.is_patch != b_it->second.is_patch) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
-                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
-                                "Decoration mismatch on location %u.%u: is per-%s in %s stage but "
-                                "per-%s in %s stage",
-                                a_first.first, a_first.second, a_it->second.is_patch ? "patch" : "vertex", producer_stage->name,
-                                b_it->second.is_patch ? "patch" : "vertex", consumer_stage->name);
-            }
-            if (a_it->second.is_relaxed_precision != b_it->second.is_relaxed_precision) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
-                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
-                                "Decoration mismatch on location %u.%u: %s and %s stages differ in precision", a_first.first,
-                                a_first.second, producer_stage->name, consumer_stage->name);
-            }
-            a_it++;
-            b_it++;
-        }
-    }
-
-    return skip;
-}
-
-enum FORMAT_TYPE {
-    FORMAT_TYPE_FLOAT = 1,  // UNORM, SNORM, FLOAT, USCALED, SSCALED, SRGB -- anything we consider float in the shader
-    FORMAT_TYPE_SINT = 2,
-    FORMAT_TYPE_UINT = 4,
-};
-
-static unsigned get_format_type(VkFormat fmt) {
-    if (FormatIsSInt(fmt))
-        return FORMAT_TYPE_SINT;
-    if (FormatIsUInt(fmt))
-        return FORMAT_TYPE_UINT;
-    if (FormatIsDepthAndStencil(fmt))
-        return FORMAT_TYPE_FLOAT | FORMAT_TYPE_UINT;
-    if (fmt == VK_FORMAT_UNDEFINED)
-        return 0;
-    // everything else -- UNORM/SNORM/FLOAT/USCALED/SSCALED is all float in the shader.
-    return FORMAT_TYPE_FLOAT;
-}
-
-// characterizes a SPIR-V type appearing in an interface to a FF stage, for comparison to a VkFormat's characterization above.
-static unsigned get_fundamental_type(shader_module const *src, unsigned type) {
-    auto insn = src->get_def(type);
-    assert(insn != src->end());
-
-    switch (insn.opcode()) {
-        case spv::OpTypeInt:
-            return insn.word(3) ? FORMAT_TYPE_SINT : FORMAT_TYPE_UINT;
-        case spv::OpTypeFloat:
-            return FORMAT_TYPE_FLOAT;
-        case spv::OpTypeVector:
-            return get_fundamental_type(src, insn.word(2));
-        case spv::OpTypeMatrix:
-            return get_fundamental_type(src, insn.word(2));
-        case spv::OpTypeArray:
-            return get_fundamental_type(src, insn.word(2));
-        case spv::OpTypePointer:
-            return get_fundamental_type(src, insn.word(3));
-        case spv::OpTypeImage:
-            return get_fundamental_type(src, insn.word(2));
-
-        default:
-            return 0;
-    }
-}
-
-static uint32_t get_shader_stage_id(VkShaderStageFlagBits stage) {
-    uint32_t bit_pos = uint32_t(u_ffs(stage));
-    return bit_pos - 1;
-}
-
-static bool validate_vi_consistency(debug_report_data *report_data, VkPipelineVertexInputStateCreateInfo const *vi) {
-    // Walk the binding descriptions, which describe the step rate and stride of each vertex buffer.  Each binding should
-    // be specified only once.
-    std::unordered_map<uint32_t, VkVertexInputBindingDescription const *> bindings;
-    bool skip = false;
-
-    for (unsigned i = 0; i < vi->vertexBindingDescriptionCount; i++) {
-        auto desc = &vi->pVertexBindingDescriptions[i];
-        auto &binding = bindings[desc->binding];
-        if (binding) {
-            // TODO: VALIDATION_ERROR_096005cc perhaps?
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                        SHADER_CHECKER_INCONSISTENT_VI, "SC", "Duplicate vertex input binding descriptions for binding %d",
-                        desc->binding);
-        } else {
-            binding = desc;
-        }
-    }
-
-    return skip;
-}
-
-static bool validate_vi_against_vs_inputs(debug_report_data *report_data, VkPipelineVertexInputStateCreateInfo const *vi,
-                                          shader_module const *vs, spirv_inst_iter entrypoint) {
-    bool skip = false;
-
-    auto inputs = collect_interface_by_location(vs, entrypoint, spv::StorageClassInput, false);
-
-    // Build index by location
-    std::map<uint32_t, VkVertexInputAttributeDescription const *> attribs;
-    if (vi) {
-        for (unsigned i = 0; i < vi->vertexAttributeDescriptionCount; i++) {
-            auto num_locations = get_locations_consumed_by_format(vi->pVertexAttributeDescriptions[i].format);
-            for (auto j = 0u; j < num_locations; j++) {
-                attribs[vi->pVertexAttributeDescriptions[i].location + j] = &vi->pVertexAttributeDescriptions[i];
-            }
-        }
-    }
-
-    auto it_a = attribs.begin();
-    auto it_b = inputs.begin();
-    bool used = false;
-
-    while ((attribs.size() > 0 && it_a != attribs.end()) || (inputs.size() > 0 && it_b != inputs.end())) {
-        bool a_at_end = attribs.size() == 0 || it_a == attribs.end();
-        bool b_at_end = inputs.size() == 0 || it_b == inputs.end();
-        auto a_first = a_at_end ? 0 : it_a->first;
-        auto b_first = b_at_end ? 0 : it_b->first.first;
-        if (!a_at_end && (b_at_end || a_first < b_first)) {
-            if (!used && log_msg(report_data, VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT,
-                                 0, __LINE__, SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
-                                 "Vertex attribute at location %d not consumed by vertex shader", a_first)) {
-                skip = true;
-            }
-            used = false;
-            it_a++;
-        } else if (!b_at_end && (a_at_end || b_first < a_first)) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
-                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "Vertex shader consumes input at location %d but not provided",
-                            b_first);
-            it_b++;
-        } else {
-            unsigned attrib_type = get_format_type(it_a->second->format);
-            unsigned input_type = get_fundamental_type(vs, it_b->second.type_id);
-
-            // Type checking
-            if (!(attrib_type & input_type)) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
-                                "Attribute type of `%s` at location %d does not match vertex shader input type of `%s`",
-                                string_VkFormat(it_a->second->format), a_first, describe_type(vs, it_b->second.type_id).c_str());
-            }
-
-            // OK!
-            used = true;
-            it_b++;
-        }
-    }
-
-    return skip;
-}
-
-static bool validate_fs_outputs_against_render_pass(debug_report_data *report_data, shader_module const *fs,
-                                                    spirv_inst_iter entrypoint, VkRenderPassCreateInfo const *rpci,
-                                                    uint32_t subpass_index) {
-    std::map<uint32_t, VkFormat> color_attachments;
-    auto subpass = rpci->pSubpasses[subpass_index];
-    for (auto i = 0u; i < subpass.colorAttachmentCount; ++i) {
-        uint32_t attachment = subpass.pColorAttachments[i].attachment;
-        if (attachment == VK_ATTACHMENT_UNUSED) continue;
-        if (rpci->pAttachments[attachment].format != VK_FORMAT_UNDEFINED) {
-            color_attachments[i] = rpci->pAttachments[attachment].format;
-        }
-    }
-
-    bool skip = false;
-
-    // TODO: dual source blend index (spv::DecIndex, zero if not provided)
-
-    auto outputs = collect_interface_by_location(fs, entrypoint, spv::StorageClassOutput, false);
-
-    auto it_a = outputs.begin();
-    auto it_b = color_attachments.begin();
-
-    // Walk attachment list and outputs together
-
-    while ((outputs.size() > 0 && it_a != outputs.end()) || (color_attachments.size() > 0 && it_b != color_attachments.end())) {
-        bool a_at_end = outputs.size() == 0 || it_a == outputs.end();
-        bool b_at_end = color_attachments.size() == 0 || it_b == color_attachments.end();
-
-        if (!a_at_end && (b_at_end || it_a->first.first < it_b->first)) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
-                            "fragment shader writes to output location %d with no matching attachment", it_a->first.first);
-            it_a++;
-        } else if (!b_at_end && (a_at_end || it_a->first.first > it_b->first)) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "Attachment %d not written by fragment shader", it_b->first);
-            it_b++;
-        } else {
-            unsigned output_type = get_fundamental_type(fs, it_a->second.type_id);
-            unsigned att_type = get_format_type(it_b->second);
-
-            // Type checking
-            if (!(output_type & att_type)) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
-                                "Attachment %d of type `%s` does not match fragment shader output type of `%s`", it_b->first,
-                                string_VkFormat(it_b->second), describe_type(fs, it_a->second.type_id).c_str());
-            }
-
-            // OK!
-            it_a++;
-            it_b++;
-        }
-    }
-
-    return skip;
-}
-
-// For some analyses, we need to know about all ids referenced by the static call tree of a particular entrypoint. This is
-// important for identifying the set of shader resources actually used by an entrypoint, for example.
-// Note: we only explore parts of the image which might actually contain ids we care about for the above analyses.
-//  - NOT the shader input/output interfaces.
-//
-// TODO: The set of interesting opcodes here was determined by eyeballing the SPIRV spec. It might be worth
-// converting parts of this to be generated from the machine-readable spec instead.
-static std::unordered_set<uint32_t> mark_accessible_ids(shader_module const *src, spirv_inst_iter entrypoint) {
-    std::unordered_set<uint32_t> ids;
-    std::unordered_set<uint32_t> worklist;
-    worklist.insert(entrypoint.word(2));
-
-    while (!worklist.empty()) {
-        auto id_iter = worklist.begin();
-        auto id = *id_iter;
-        worklist.erase(id_iter);
-
-        auto insn = src->get_def(id);
-        if (insn == src->end()) {
-            // ID is something we didn't collect in build_def_index. that's OK -- we'll stumble across all kinds of things here
-            // that we may not care about.
-            continue;
-        }
-
-        // Try to add to the output set
-        if (!ids.insert(id).second) {
-            continue;  // If we already saw this id, we don't want to walk it again.
-        }
-
-        switch (insn.opcode()) {
-            case spv::OpFunction:
-                // Scan whole body of the function, enlisting anything interesting
-                while (++insn, insn.opcode() != spv::OpFunctionEnd) {
-                    switch (insn.opcode()) {
-                        case spv::OpLoad:
-                        case spv::OpAtomicLoad:
-                        case spv::OpAtomicExchange:
-                        case spv::OpAtomicCompareExchange:
-                        case spv::OpAtomicCompareExchangeWeak:
-                        case spv::OpAtomicIIncrement:
-                        case spv::OpAtomicIDecrement:
-                        case spv::OpAtomicIAdd:
-                        case spv::OpAtomicISub:
-                        case spv::OpAtomicSMin:
-                        case spv::OpAtomicUMin:
-                        case spv::OpAtomicSMax:
-                        case spv::OpAtomicUMax:
-                        case spv::OpAtomicAnd:
-                        case spv::OpAtomicOr:
-                        case spv::OpAtomicXor:
-                            worklist.insert(insn.word(3));  // ptr
-                            break;
-                        case spv::OpStore:
-                        case spv::OpAtomicStore:
-                            worklist.insert(insn.word(1));  // ptr
-                            break;
-                        case spv::OpAccessChain:
-                        case spv::OpInBoundsAccessChain:
-                            worklist.insert(insn.word(3));  // base ptr
-                            break;
-                        case spv::OpSampledImage:
-                        case spv::OpImageSampleImplicitLod:
-                        case spv::OpImageSampleExplicitLod:
-                        case spv::OpImageSampleDrefImplicitLod:
-                        case spv::OpImageSampleDrefExplicitLod:
-                        case spv::OpImageSampleProjImplicitLod:
-                        case spv::OpImageSampleProjExplicitLod:
-                        case spv::OpImageSampleProjDrefImplicitLod:
-                        case spv::OpImageSampleProjDrefExplicitLod:
-                        case spv::OpImageFetch:
-                        case spv::OpImageGather:
-                        case spv::OpImageDrefGather:
-                        case spv::OpImageRead:
-                        case spv::OpImage:
-                        case spv::OpImageQueryFormat:
-                        case spv::OpImageQueryOrder:
-                        case spv::OpImageQuerySizeLod:
-                        case spv::OpImageQuerySize:
-                        case spv::OpImageQueryLod:
-                        case spv::OpImageQueryLevels:
-                        case spv::OpImageQuerySamples:
-                        case spv::OpImageSparseSampleImplicitLod:
-                        case spv::OpImageSparseSampleExplicitLod:
-                        case spv::OpImageSparseSampleDrefImplicitLod:
-                        case spv::OpImageSparseSampleDrefExplicitLod:
-                        case spv::OpImageSparseSampleProjImplicitLod:
-                        case spv::OpImageSparseSampleProjExplicitLod:
-                        case spv::OpImageSparseSampleProjDrefImplicitLod:
-                        case spv::OpImageSparseSampleProjDrefExplicitLod:
-                        case spv::OpImageSparseFetch:
-                        case spv::OpImageSparseGather:
-                        case spv::OpImageSparseDrefGather:
-                        case spv::OpImageTexelPointer:
-                            worklist.insert(insn.word(3));  // Image or sampled image
-                            break;
-                        case spv::OpImageWrite:
-                            worklist.insert(insn.word(1));  // Image -- different operand order to above
-                            break;
-                        case spv::OpFunctionCall:
-                            for (uint32_t i = 3; i < insn.len(); i++) {
-                                worklist.insert(insn.word(i));  // fn itself, and all args
-                            }
-                            break;
-
-                        case spv::OpExtInst:
-                            for (uint32_t i = 5; i < insn.len(); i++) {
-                                worklist.insert(insn.word(i));  // Operands to ext inst
-                            }
-                            break;
-                    }
-                }
-                break;
-        }
-    }
-
-    return ids;
-}
-
-static bool validate_push_constant_block_against_pipeline(debug_report_data *report_data,
-                                                          std::vector<VkPushConstantRange> const *push_constant_ranges,
-                                                          shader_module const *src, spirv_inst_iter type,
-                                                          VkShaderStageFlagBits stage) {
-    bool skip = false;
-
-    // Strip off ptrs etc
-    type = get_struct_type(src, type, false);
-    assert(type != src->end());
-
-    // Validate directly off the offsets. this isn't quite correct for arrays and matrices, but is a good first step.
-    // TODO: arrays, matrices, weird sizes
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
-            if (insn.word(3) == spv::DecorationOffset) {
-                unsigned offset = insn.word(4);
-                auto size = 4;  // Bytes; TODO: calculate this based on the type
-
-                bool found_range = false;
-                for (auto const &range : *push_constant_ranges) {
-                    if (range.offset <= offset && range.offset + range.size >= offset + size) {
-                        found_range = true;
-
-                        if ((range.stageFlags & stage) == 0) {
-                            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
-                                            __LINE__, SHADER_CHECKER_PUSH_CONSTANT_NOT_ACCESSIBLE_FROM_STAGE, "SC",
-                                            "Push constant range covering variable starting at "
-                                            "offset %u not accessible from stage %s",
-                                            offset, string_VkShaderStageFlagBits(stage));
-                        }
-
-                        break;
-                    }
-                }
-
-                if (!found_range) {
-                    skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
-                                    __LINE__, SHADER_CHECKER_PUSH_CONSTANT_OUT_OF_RANGE, "SC",
-                                    "Push constant range covering variable starting at "
-                                    "offset %u not declared in layout",
-                                    offset);
-                }
-            }
-        }
-    }
-
-    return skip;
-}
-
-static bool validate_push_constant_usage(debug_report_data *report_data,
-                                         std::vector<VkPushConstantRange> const *push_constant_ranges, shader_module const *src,
-                                         std::unordered_set<uint32_t> accessible_ids, VkShaderStageFlagBits stage) {
-    bool skip = false;
-
-    for (auto id : accessible_ids) {
-        auto def_insn = src->get_def(id);
-        if (def_insn.opcode() == spv::OpVariable && def_insn.word(3) == spv::StorageClassPushConstant) {
-            skip |= validate_push_constant_block_against_pipeline(report_data, push_constant_ranges, src,
-                                                                  src->get_def(def_insn.word(1)), stage);
-        }
-    }
-
-    return skip;
-}
-
-// For given pipelineLayout verify that the set_layout_node at slot.first
-//  has the requested binding at slot.second and return ptr to that binding
-static VkDescriptorSetLayoutBinding const *get_descriptor_binding(PIPELINE_LAYOUT_NODE const *pipelineLayout,
-                                                                  descriptor_slot_t slot) {
-    if (!pipelineLayout) return nullptr;
-
-    if (slot.first >= pipelineLayout->set_layouts.size()) return nullptr;
-
-    return pipelineLayout->set_layouts[slot.first]->GetDescriptorSetLayoutBindingPtrFromBinding(slot.second);
-}
-
 // Check object status for selected flag state
 static bool validate_status(layer_data *dev_data, GLOBAL_CB_NODE *pNode, CBStatusFlags status_mask, VkFlags msg_flags,
                             const char *fail_msg, UNIQUE_VALIDATION_ERROR_CODE const msg_code) {
@@ -1856,6 +729,14 @@ static PIPELINE_LAYOUT_NODE const *getPipelineLayout(layer_data const *dev_data,
     return &it->second;
 }
 
+shader_module const *GetShaderModuleState(layer_data const *dev_data, VkShaderModule module) {
+    auto it = dev_data->shaderModuleMap.find(module);
+    if (it == dev_data->shaderModuleMap.end()) {
+        return nullptr;
+    }
+    return it->second.get();
+}
+
 // Return true if for a given PSO, the given state enum is dynamic, else return false
 static bool isDynamic(const PIPELINE_STATE *pPipeline, const VkDynamicState state) {
     if (pPipeline && pPipeline->graphicsPipelineCI.pDynamicState) {
@@ -2006,447 +887,6 @@ static bool verify_renderpass_compatibility(const layer_data *dev_data, const Vk
     return true;
 }
 
-// For given cvdescriptorset::DescriptorSet, verify that its Set is compatible w/ the setLayout corresponding to
-// pipelineLayout[layoutIndex]
-static bool verify_set_layout_compatibility(const cvdescriptorset::DescriptorSet *descriptor_set,
-                                            PIPELINE_LAYOUT_NODE const *pipeline_layout, const uint32_t layoutIndex,
-                                            string &errorMsg) {
-    auto num_sets = pipeline_layout->set_layouts.size();
-    if (layoutIndex >= num_sets) {
-        stringstream errorStr;
-        errorStr << "VkPipelineLayout (" << pipeline_layout->layout << ") only contains " << num_sets
-                 << " setLayouts corresponding to sets 0-" << num_sets - 1 << ", but you're attempting to bind set to index "
-                 << layoutIndex;
-        errorMsg = errorStr.str();
-        return false;
-    }
-    auto layout_node = pipeline_layout->set_layouts[layoutIndex];
-    return descriptor_set->IsCompatible(layout_node, &errorMsg);
-}
-
-// Validate that data for each specialization entry is fully contained within the buffer.
-static bool validate_specialization_offsets(debug_report_data *report_data, VkPipelineShaderStageCreateInfo const *info) {
-    bool skip = false;
-
-    VkSpecializationInfo const *spec = info->pSpecializationInfo;
-
-    if (spec) {
-        for (auto i = 0u; i < spec->mapEntryCount; i++) {
-            // TODO: This is a good place for VALIDATION_ERROR_1360060a.
-            if (spec->pMapEntries[i].offset + spec->pMapEntries[i].size > spec->dataSize) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
-                                VALIDATION_ERROR_1360060c, "SC",
-                                "Specialization entry %u (for constant id %u) references memory outside provided "
-                                "specialization data (bytes %u.." PRINTF_SIZE_T_SPECIFIER "; " PRINTF_SIZE_T_SPECIFIER
-                                " bytes provided). %s.",
-                                i, spec->pMapEntries[i].constantID, spec->pMapEntries[i].offset,
-                                spec->pMapEntries[i].offset + spec->pMapEntries[i].size - 1, spec->dataSize,
-                                validation_error_map[VALIDATION_ERROR_1360060c]);
-            }
-        }
-    }
-
-    return skip;
-}
-
-static bool descriptor_type_match(shader_module const *module, uint32_t type_id, VkDescriptorType descriptor_type,
-                                  unsigned &descriptor_count) {
-    auto type = module->get_def(type_id);
-
-    descriptor_count = 1;
-
-    // Strip off any array or ptrs. Where we remove array levels, adjust the  descriptor count for each dimension.
-    while (type.opcode() == spv::OpTypeArray || type.opcode() == spv::OpTypePointer) {
-        if (type.opcode() == spv::OpTypeArray) {
-            descriptor_count *= get_constant_value(module, type.word(3));
-            type = module->get_def(type.word(2));
-        } else {
-            type = module->get_def(type.word(3));
-        }
-    }
-
-    switch (type.opcode()) {
-        case spv::OpTypeStruct: {
-            for (auto insn : *module) {
-                if (insn.opcode() == spv::OpDecorate && insn.word(1) == type.word(1)) {
-                    if (insn.word(2) == spv::DecorationBlock) {
-                        return descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER ||
-                               descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
-                    } else if (insn.word(2) == spv::DecorationBufferBlock) {
-                        return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER ||
-                               descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC;
-                    }
-                }
-            }
-
-            // Invalid
-            return false;
-        }
-
-        case spv::OpTypeSampler:
-            return descriptor_type == VK_DESCRIPTOR_TYPE_SAMPLER || descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
-
-        case spv::OpTypeSampledImage:
-            if (descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER) {
-                // Slight relaxation for some GLSL historical madness: samplerBuffer doesn't really have a sampler, and a texel
-                // buffer descriptor doesn't really provide one. Allow this slight mismatch.
-                auto image_type = module->get_def(type.word(2));
-                auto dim = image_type.word(3);
-                auto sampled = image_type.word(7);
-                return dim == spv::DimBuffer && sampled == 1;
-            }
-            return descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
-
-        case spv::OpTypeImage: {
-            // Many descriptor types backing image types-- depends on dimension and whether the image will be used with a sampler.
-            // SPIRV for Vulkan requires that sampled be 1 or 2 -- leaving the decision to runtime is unacceptable.
-            auto dim = type.word(3);
-            auto sampled = type.word(7);
-
-            if (dim == spv::DimSubpassData) {
-                return descriptor_type == VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT;
-            } else if (dim == spv::DimBuffer) {
-                if (sampled == 1) {
-                    return descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER;
-                } else {
-                    return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER;
-                }
-            } else if (sampled == 1) {
-                return descriptor_type == VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE ||
-                       descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
-            } else {
-                return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
-            }
-        }
-
-        // We shouldn't really see any other junk types -- but if we do, they're a mismatch.
-        default:
-            return false;  // Mismatch
-    }
-}
-
-static bool require_feature(debug_report_data *report_data, VkBool32 feature, char const *feature_name) {
-    if (!feature) {
-        if (log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                    SHADER_CHECKER_FEATURE_NOT_ENABLED, "SC",
-                    "Shader requires VkPhysicalDeviceFeatures::%s but is not "
-                    "enabled on the device",
-                    feature_name)) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
-static bool require_extension(debug_report_data *report_data, bool extension, char const *extension_name) {
-    if (!extension) {
-        if (log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                    SHADER_CHECKER_FEATURE_NOT_ENABLED, "SC",
-                    "Shader requires extension %s but is not "
-                    "enabled on the device",
-                    extension_name)) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
-static bool validate_shader_capabilities(layer_data *dev_data, shader_module const *src) {
-    bool skip = false;
-
-    auto report_data = dev_data->report_data;
-    auto const & enabledFeatures = dev_data->enabled_features;
-
-    struct CapabilityInfo {
-        char const *name;
-        VkBool32 const VkPhysicalDeviceFeatures::*feature;
-        bool const DeviceExtensions::*extension;
-    };
-
-    using F = VkPhysicalDeviceFeatures;
-    using E = DeviceExtensions;
-
-    // clang-format off
-    static const std::unordered_map<uint32_t, CapabilityInfo> capabilities = {
-        // Capabilities always supported by a Vulkan 1.0 implementation -- no
-        // feature bits.
-        {spv::CapabilityMatrix, {nullptr}},
-        {spv::CapabilityShader, {nullptr}},
-        {spv::CapabilityInputAttachment, {nullptr}},
-        {spv::CapabilitySampled1D, {nullptr}},
-        {spv::CapabilityImage1D, {nullptr}},
-        {spv::CapabilitySampledBuffer, {nullptr}},
-        {spv::CapabilityImageQuery, {nullptr}},
-        {spv::CapabilityDerivativeControl, {nullptr}},
-
-        // Capabilities that are optionally supported, but require a feature to
-        // be enabled on the device
-        {spv::CapabilityGeometry, {"geometryShader", &F::geometryShader}},
-        {spv::CapabilityTessellation, {"tessellationShader", &F::tessellationShader}},
-        {spv::CapabilityFloat64, {"shaderFloat64", &F::shaderFloat64}},
-        {spv::CapabilityInt64, {"shaderInt64", &F::shaderInt64}},
-        {spv::CapabilityTessellationPointSize, {"shaderTessellationAndGeometryPointSize", &F::shaderTessellationAndGeometryPointSize}},
-        {spv::CapabilityGeometryPointSize, {"shaderTessellationAndGeometryPointSize", &F::shaderTessellationAndGeometryPointSize}},
-        {spv::CapabilityImageGatherExtended, {"shaderImageGatherExtended", &F::shaderImageGatherExtended}},
-        {spv::CapabilityStorageImageMultisample, {"shaderStorageImageMultisample", &F::shaderStorageImageMultisample}},
-        {spv::CapabilityUniformBufferArrayDynamicIndexing, {"shaderUniformBufferArrayDynamicIndexing", &F::shaderUniformBufferArrayDynamicIndexing}},
-        {spv::CapabilitySampledImageArrayDynamicIndexing, {"shaderSampledImageArrayDynamicIndexing", &F::shaderSampledImageArrayDynamicIndexing}},
-        {spv::CapabilityStorageBufferArrayDynamicIndexing, {"shaderStorageBufferArrayDynamicIndexing", &F::shaderStorageBufferArrayDynamicIndexing}},
-        {spv::CapabilityStorageImageArrayDynamicIndexing, {"shaderStorageImageArrayDynamicIndexing", &F::shaderStorageBufferArrayDynamicIndexing}},
-        {spv::CapabilityClipDistance, {"shaderClipDistance", &F::shaderClipDistance}},
-        {spv::CapabilityCullDistance, {"shaderCullDistance", &F::shaderCullDistance}},
-        {spv::CapabilityImageCubeArray, {"imageCubeArray", &F::imageCubeArray}},
-        {spv::CapabilitySampleRateShading, {"sampleRateShading", &F::sampleRateShading}},
-        {spv::CapabilitySparseResidency, {"shaderResourceResidency", &F::shaderResourceResidency}},
-        {spv::CapabilityMinLod, {"shaderResourceMinLod", &F::shaderResourceMinLod}},
-        {spv::CapabilitySampledCubeArray, {"imageCubeArray", &F::imageCubeArray}},
-        {spv::CapabilityImageMSArray, {"shaderStorageImageMultisample", &F::shaderStorageImageMultisample}},
-        {spv::CapabilityStorageImageExtendedFormats, {"shaderStorageImageExtendedFormats", &F::shaderStorageImageExtendedFormats}},
-        {spv::CapabilityInterpolationFunction, {"sampleRateShading", &F::sampleRateShading}},
-        {spv::CapabilityStorageImageReadWithoutFormat, {"shaderStorageImageReadWithoutFormat", &F::shaderStorageImageReadWithoutFormat}},
-        {spv::CapabilityStorageImageWriteWithoutFormat, {"shaderStorageImageWriteWithoutFormat", &F::shaderStorageImageWriteWithoutFormat}},
-        {spv::CapabilityMultiViewport, {"multiViewport", &F::multiViewport}},
-
-        // Capabilities that require an extension
-        {spv::CapabilityDrawParameters, {VK_KHR_SHADER_DRAW_PARAMETERS_EXTENSION_NAME, nullptr, &E::vk_khr_shader_draw_parameters}},
-        {spv::CapabilityGeometryShaderPassthroughNV, {VK_NV_GEOMETRY_SHADER_PASSTHROUGH_EXTENSION_NAME, nullptr, &E::vk_nv_geometry_shader_passthrough}},
-        {spv::CapabilitySampleMaskOverrideCoverageNV, {VK_NV_SAMPLE_MASK_OVERRIDE_COVERAGE_EXTENSION_NAME, nullptr, &E::vk_nv_sample_mask_override_coverage}},
-        {spv::CapabilityShaderViewportIndexLayerNV, {VK_NV_VIEWPORT_ARRAY2_EXTENSION_NAME, nullptr, &E::vk_nv_viewport_array2}},
-        {spv::CapabilityShaderViewportMaskNV, {VK_NV_VIEWPORT_ARRAY2_EXTENSION_NAME, nullptr, &E::vk_nv_viewport_array2}},
-        {spv::CapabilitySubgroupBallotKHR, {VK_EXT_SHADER_SUBGROUP_BALLOT_EXTENSION_NAME, nullptr, &E::vk_ext_shader_subgroup_ballot }},
-        {spv::CapabilitySubgroupVoteKHR, {VK_EXT_SHADER_SUBGROUP_VOTE_EXTENSION_NAME, nullptr, &E::vk_ext_shader_subgroup_vote }},
-    };
-    // clang-format on
-
-    for (auto insn : *src) {
-        if (insn.opcode() == spv::OpCapability) {
-            auto it = capabilities.find(insn.word(1));
-            if (it != capabilities.end()) {
-                if (it->second.feature) {
-                    skip |= require_feature(report_data, enabledFeatures.*(it->second.feature), it->second.name);
-                }
-                if (it->second.extension) {
-                    skip |= require_extension(report_data, dev_data->extensions.*(it->second.extension), it->second.name);
-                }
-            }
-        }
-    }
-
-    return skip;
-}
-
-static uint32_t descriptor_type_to_reqs(shader_module const *module, uint32_t type_id) {
-    auto type = module->get_def(type_id);
-
-    while (true) {
-        switch (type.opcode()) {
-            case spv::OpTypeArray:
-            case spv::OpTypeSampledImage:
-                type = module->get_def(type.word(2));
-                break;
-            case spv::OpTypePointer:
-                type = module->get_def(type.word(3));
-                break;
-            case spv::OpTypeImage: {
-                auto dim = type.word(3);
-                auto arrayed = type.word(5);
-                auto msaa = type.word(6);
-
-                switch (dim) {
-                    case spv::Dim1D:
-                        return arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_1D_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_1D;
-                    case spv::Dim2D:
-                        return (msaa ? DESCRIPTOR_REQ_MULTI_SAMPLE : DESCRIPTOR_REQ_SINGLE_SAMPLE) |
-                               (arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_2D_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_2D);
-                    case spv::Dim3D:
-                        return DESCRIPTOR_REQ_VIEW_TYPE_3D;
-                    case spv::DimCube:
-                        return arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_CUBE_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_CUBE;
-                    case spv::DimSubpassData:
-                        return msaa ? DESCRIPTOR_REQ_MULTI_SAMPLE : DESCRIPTOR_REQ_SINGLE_SAMPLE;
-                    default:  // buffer, etc.
-                        return 0;
-                }
-            }
-            default:
-                return 0;
-        }
-    }
-}
-
-static bool validate_pipeline_shader_stage(
-    layer_data *dev_data, VkPipelineShaderStageCreateInfo const *pStage, PIPELINE_STATE *pipeline,
-    shader_module **out_module, spirv_inst_iter *out_entrypoint) {
-    bool skip = false;
-    auto module_it = dev_data->shaderModuleMap.find(pStage->module);
-    auto module = *out_module = module_it->second.get();
-    auto report_data = dev_data->report_data;
-
-    if (!module->has_valid_spirv) return false;
-
-    // Find the entrypoint
-    auto entrypoint = *out_entrypoint = find_entrypoint(module, pStage->pName, pStage->stage);
-    if (entrypoint == module->end()) {
-        if (log_msg(dev_data->report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                    VALIDATION_ERROR_10600586, "SC", "No entrypoint found named `%s` for stage %s. %s.", pStage->pName,
-                    string_VkShaderStageFlagBits(pStage->stage), validation_error_map[VALIDATION_ERROR_10600586])) {
-            return true;  // no point continuing beyond here, any analysis is just going to be garbage.
-        }
-    }
-
-    // Validate shader capabilities against enabled device features
-    skip |= validate_shader_capabilities(dev_data, module);
-
-    // Mark accessible ids
-    auto accessible_ids = mark_accessible_ids(module, entrypoint);
-
-    // Validate descriptor set layout against what the entrypoint actually uses
-    auto descriptor_uses = collect_interface_by_descriptor_slot(report_data, module, accessible_ids);
-
-    auto pipelineLayout = pipeline->pipeline_layout;
-
-    skip |= validate_specialization_offsets(report_data, pStage);
-    skip |= validate_push_constant_usage(report_data, &pipelineLayout.push_constant_ranges, module, accessible_ids, pStage->stage);
-
-    // Validate descriptor use
-    for (auto use : descriptor_uses) {
-        // While validating shaders capture which slots are used by the pipeline
-        auto &reqs = pipeline->active_slots[use.first.first][use.first.second];
-        reqs = descriptor_req(reqs | descriptor_type_to_reqs(module, use.second.type_id));
-
-        // Verify given pipelineLayout has requested setLayout with requested binding
-        const auto &binding = get_descriptor_binding(&pipelineLayout, use.first);
-        unsigned required_descriptor_count;
-
-        if (!binding) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_MISSING_DESCRIPTOR, "SC",
-                            "Shader uses descriptor slot %u.%u (used as type `%s`) but not declared in pipeline layout",
-                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str());
-        } else if (~binding->stageFlags & pStage->stage) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
-                            SHADER_CHECKER_DESCRIPTOR_NOT_ACCESSIBLE_FROM_STAGE, "SC",
-                            "Shader uses descriptor slot %u.%u (used "
-                            "as type `%s`) but descriptor not "
-                            "accessible from stage %s",
-                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str(),
-                            string_VkShaderStageFlagBits(pStage->stage));
-        } else if (!descriptor_type_match(module, use.second.type_id, binding->descriptorType, required_descriptor_count)) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_DESCRIPTOR_TYPE_MISMATCH, "SC",
-                            "Type mismatch on descriptor slot "
-                            "%u.%u (used as type `%s`) but "
-                            "descriptor of type %s",
-                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str(),
-                            string_VkDescriptorType(binding->descriptorType));
-        } else if (binding->descriptorCount < required_descriptor_count) {
-            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_DESCRIPTOR_TYPE_MISMATCH, "SC",
-                            "Shader expects at least %u descriptors for binding %u.%u (used as type `%s`) but only %u provided",
-                            required_descriptor_count, use.first.first, use.first.second,
-                            describe_type(module, use.second.type_id).c_str(), binding->descriptorCount);
-        }
-    }
-
-    // Validate use of input attachments against subpass structure
-    if (pStage->stage == VK_SHADER_STAGE_FRAGMENT_BIT) {
-        auto input_attachment_uses = collect_interface_by_input_attachment_index(module, accessible_ids);
-
-        auto rpci = pipeline->render_pass_ci.ptr();
-        auto subpass = pipeline->graphicsPipelineCI.subpass;
-
-        for (auto use : input_attachment_uses) {
-            auto input_attachments = rpci->pSubpasses[subpass].pInputAttachments;
-            auto index = (input_attachments && use.first < rpci->pSubpasses[subpass].inputAttachmentCount)
-                             ? input_attachments[use.first].attachment
-                             : VK_ATTACHMENT_UNUSED;
-
-            if (index == VK_ATTACHMENT_UNUSED) {
-                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                                SHADER_CHECKER_MISSING_INPUT_ATTACHMENT, "SC",
-                                "Shader consumes input attachment index %d but not provided in subpass", use.first);
-            } else if (!(get_format_type(rpci->pAttachments[index].format) & get_fundamental_type(module, use.second.type_id))) {
-                skip |=
-                    log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
-                            SHADER_CHECKER_INPUT_ATTACHMENT_TYPE_MISMATCH, "SC",
-                            "Subpass input attachment %u format of %s does not match type used in shader `%s`", use.first,
-                            string_VkFormat(rpci->pAttachments[index].format), describe_type(module, use.second.type_id).c_str());
-            }
-        }
-    }
-
-    return skip;
-}
-
-// Validate that the shaders used by the given pipeline and store the active_slots
-//  that are actually used by the pipeline into pPipeline->active_slots
-static bool validate_and_capture_pipeline_shader_state(layer_data *dev_data, PIPELINE_STATE *pPipeline) {
-    auto pCreateInfo = pPipeline->graphicsPipelineCI.ptr();
-    int vertex_stage = get_shader_stage_id(VK_SHADER_STAGE_VERTEX_BIT);
-    int fragment_stage = get_shader_stage_id(VK_SHADER_STAGE_FRAGMENT_BIT);
-
-    shader_module *shaders[5];
-    memset(shaders, 0, sizeof(shaders));
-    spirv_inst_iter entrypoints[5];
-    memset(entrypoints, 0, sizeof(entrypoints));
-    bool skip = false;
-
-    for (uint32_t i = 0; i < pCreateInfo->stageCount; i++) {
-        auto pStage = &pCreateInfo->pStages[i];
-        auto stage_id = get_shader_stage_id(pStage->stage);
-        skip |= validate_pipeline_shader_stage(dev_data, pStage, pPipeline, &shaders[stage_id], &entrypoints[stage_id]);
-    }
-
-    // if the shader stages are no good individually, cross-stage validation is pointless.
-    if (skip) return true;
-
-    auto vi = pCreateInfo->pVertexInputState;
-
-    if (vi) {
-        skip |= validate_vi_consistency(dev_data->report_data, vi);
-    }
-
-    if (shaders[vertex_stage] && shaders[vertex_stage]->has_valid_spirv) {
-        skip |= validate_vi_against_vs_inputs(dev_data->report_data, vi, shaders[vertex_stage], entrypoints[vertex_stage]);
-    }
-
-    int producer = get_shader_stage_id(VK_SHADER_STAGE_VERTEX_BIT);
-    int consumer = get_shader_stage_id(VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT);
-
-    while (!shaders[producer] && producer != fragment_stage) {
-        producer++;
-        consumer++;
-    }
-
-    for (; producer != fragment_stage && consumer <= fragment_stage; consumer++) {
-        assert(shaders[producer]);
-        if (shaders[consumer] && shaders[consumer]->has_valid_spirv && shaders[producer]->has_valid_spirv) {
-            skip |= validate_interface_between_stages(dev_data->report_data, shaders[producer], entrypoints[producer],
-                                                      &shader_stage_attribs[producer], shaders[consumer], entrypoints[consumer],
-                                                      &shader_stage_attribs[consumer]);
-
-            producer = consumer;
-        }
-    }
-
-    if (shaders[fragment_stage] && shaders[fragment_stage]->has_valid_spirv) {
-        skip |= validate_fs_outputs_against_render_pass(dev_data->report_data, shaders[fragment_stage], entrypoints[fragment_stage],
-                                                        pPipeline->render_pass_ci.ptr(), pCreateInfo->subpass);
-    }
-
-    return skip;
-}
-
-static bool validate_compute_pipeline(layer_data *dev_data, PIPELINE_STATE *pPipeline) {
-    auto pCreateInfo = pPipeline->computePipelineCI.ptr();
-
-    shader_module *module;
-    spirv_inst_iter entrypoint;
-
-    return validate_pipeline_shader_stage(dev_data, &pCreateInfo->stage, pPipeline, &module, &entrypoint);
-}
 // Return Set node ptr for specified set or else NULL
 cvdescriptorset::DescriptorSet *GetSetNode(const layer_data *dev_data, VkDescriptorSet set) {
     auto set_it = dev_data->setMap.find(set);
@@ -2609,6 +1049,24 @@ static bool ValidatePipelineDrawtimeState(layer_data const *dev_data, LAST_BOUND
     return skip;
 }
 
+// For given cvdescriptorset::DescriptorSet, verify that its Set is compatible w/ the setLayout corresponding to
+// pipelineLayout[layoutIndex]
+static bool verify_set_layout_compatibility(const cvdescriptorset::DescriptorSet *descriptor_set,
+                                            PIPELINE_LAYOUT_NODE const *pipeline_layout, const uint32_t layoutIndex,
+                                            string &errorMsg) {
+    auto num_sets = pipeline_layout->set_layouts.size();
+    if (layoutIndex >= num_sets) {
+        stringstream errorStr;
+        errorStr << "VkPipelineLayout (" << pipeline_layout->layout << ") only contains " << num_sets
+                 << " setLayouts corresponding to sets 0-" << num_sets - 1 << ", but you're attempting to bind set to index "
+                 << layoutIndex;
+        errorMsg = errorStr.str();
+        return false;
+    }
+    auto layout_node = pipeline_layout->set_layouts[layoutIndex];
+    return descriptor_set->IsCompatible(layout_node, &errorMsg);
+}
+
 // Validate overall state at the time of a draw call
 static bool ValidateDrawState(layer_data *dev_data, GLOBAL_CB_NODE *cb_node, const bool indexed,
                               const VkPipelineBindPoint bind_point, const char *function,
diff --git a/layers/core_validation_types.h b/layers/core_validation_types.h
index eca0aae0..1555850d 100644
--- a/layers/core_validation_types.h
+++ b/layers/core_validation_types.h
@@ -751,6 +751,9 @@ public:
         : framebuffer(fb), createInfo(pCreateInfo), renderPassCreateInfo(pRPCI) {};
 };
 
+struct shader_module;
+struct DeviceExtensions;
+
 // Fwd declarations of layer_data and helpers to look-up/validate state from layer_data maps
 namespace core_validation {
 struct layer_data;
@@ -768,8 +771,10 @@ GLOBAL_CB_NODE *GetCBNode(layer_data const *my_data, const VkCommandBuffer cb);
 RENDER_PASS_STATE *GetRenderPassState(layer_data const *my_data, VkRenderPass renderpass);
 FRAMEBUFFER_STATE *GetFramebufferState(const layer_data *my_data, VkFramebuffer framebuffer);
 COMMAND_POOL_NODE *GetCommandPoolNode(layer_data *dev_data, VkCommandPool pool);
+shader_module const *GetShaderModuleState(layer_data const *dev_data, VkShaderModule module);
 const PHYS_DEV_PROPERTIES_NODE *GetPhysDevProperties(const layer_data *device_data);
 const VkPhysicalDeviceFeatures *GetEnabledFeatures(const layer_data *device_data);
+const DeviceExtensions *GetEnabledExtensions(const layer_data *device_data);
 
 void invalidateCommandBuffers(const layer_data *, std::unordered_set<GLOBAL_CB_NODE *> const &, VK_OBJECT);
 bool ValidateMemoryIsBoundToBuffer(const layer_data *, const BUFFER_STATE *, const char *, UNIQUE_VALIDATION_ERROR_CODE);
diff --git a/layers/shader_validation.cpp b/layers/shader_validation.cpp
new file mode 100644
index 00000000..fc44d41b
--- /dev/null
+++ b/layers/shader_validation.cpp
@@ -0,0 +1,1511 @@
+/* Copyright (c) 2015-2017 The Khronos Group Inc.
+ * Copyright (c) 2015-2017 Valve Corporation
+ * Copyright (c) 2015-2017 LunarG, Inc.
+ * Copyright (C) 2015-2017 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Author: Chris Forbes <chrisf@ijw.co.nz>
+ */
+
+#include <cinttypes>
+#include <cassert>
+#include <vector>
+#include <unordered_map>
+#include <string>
+#include <sstream>
+#include <SPIRV/spirv.hpp>
+#include "vk_loader_platform.h"
+#include "vk_enum_string_helper.h"
+#include "vk_layer_table.h"
+#include "vk_layer_data.h"
+#include "vk_layer_extension_utils.h"
+#include "vk_layer_utils.h"
+#include "core_validation.h"
+#include "core_validation_types.h"
+#include "shader_validation.h"
+
+enum FORMAT_TYPE {
+    FORMAT_TYPE_FLOAT = 1,  // UNORM, SNORM, FLOAT, USCALED, SSCALED, SRGB -- anything we consider float in the shader
+    FORMAT_TYPE_SINT = 2,
+    FORMAT_TYPE_UINT = 4,
+};
+
+typedef std::pair<unsigned, unsigned> location_t;
+
+struct interface_var {
+    uint32_t id;
+    uint32_t type_id;
+    uint32_t offset;
+    bool is_patch;
+    bool is_block_member;
+    bool is_relaxed_precision;
+    // TODO: collect the name, too? Isn't required to be present.
+};
+
+struct shader_stage_attributes {
+    char const *const name;
+    bool arrayed_input;
+    bool arrayed_output;
+};
+
+static shader_stage_attributes shader_stage_attribs[] = {
+    {"vertex shader", false, false},  {"tessellation control shader", true, true}, {"tessellation evaluation shader", true, false},
+    {"geometry shader", true, false}, {"fragment shader", false, false},
+};
+
+// SPIRV utility functions
+void shader_module::build_def_index() {
+    for (auto insn : *this) {
+        switch (insn.opcode()) {
+            // Types
+            case spv::OpTypeVoid:
+            case spv::OpTypeBool:
+            case spv::OpTypeInt:
+            case spv::OpTypeFloat:
+            case spv::OpTypeVector:
+            case spv::OpTypeMatrix:
+            case spv::OpTypeImage:
+            case spv::OpTypeSampler:
+            case spv::OpTypeSampledImage:
+            case spv::OpTypeArray:
+            case spv::OpTypeRuntimeArray:
+            case spv::OpTypeStruct:
+            case spv::OpTypeOpaque:
+            case spv::OpTypePointer:
+            case spv::OpTypeFunction:
+            case spv::OpTypeEvent:
+            case spv::OpTypeDeviceEvent:
+            case spv::OpTypeReserveId:
+            case spv::OpTypeQueue:
+            case spv::OpTypePipe:
+                def_index[insn.word(1)] = insn.offset();
+                break;
+
+                // Fixed constants
+            case spv::OpConstantTrue:
+            case spv::OpConstantFalse:
+            case spv::OpConstant:
+            case spv::OpConstantComposite:
+            case spv::OpConstantSampler:
+            case spv::OpConstantNull:
+                def_index[insn.word(2)] = insn.offset();
+                break;
+
+                // Specialization constants
+            case spv::OpSpecConstantTrue:
+            case spv::OpSpecConstantFalse:
+            case spv::OpSpecConstant:
+            case spv::OpSpecConstantComposite:
+            case spv::OpSpecConstantOp:
+                def_index[insn.word(2)] = insn.offset();
+                break;
+
+                // Variables
+            case spv::OpVariable:
+                def_index[insn.word(2)] = insn.offset();
+                break;
+
+                // Functions
+            case spv::OpFunction:
+                def_index[insn.word(2)] = insn.offset();
+                break;
+
+            default:
+                // We don't care about any other defs for now.
+                break;
+        }
+    }
+}
+
+static spirv_inst_iter find_entrypoint(shader_module const *src, char const *name, VkShaderStageFlagBits stageBits) {
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpEntryPoint) {
+            auto entrypointName = (char const *)&insn.word(3);
+            auto entrypointStageBits = 1u << insn.word(1);
+
+            if (!strcmp(entrypointName, name) && (entrypointStageBits & stageBits)) {
+                return insn;
+            }
+        }
+    }
+
+    return src->end();
+}
+
+static char const *storage_class_name(unsigned sc) {
+    switch (sc) {
+        case spv::StorageClassInput:
+            return "input";
+        case spv::StorageClassOutput:
+            return "output";
+        case spv::StorageClassUniformConstant:
+            return "const uniform";
+        case spv::StorageClassUniform:
+            return "uniform";
+        case spv::StorageClassWorkgroup:
+            return "workgroup local";
+        case spv::StorageClassCrossWorkgroup:
+            return "workgroup global";
+        case spv::StorageClassPrivate:
+            return "private global";
+        case spv::StorageClassFunction:
+            return "function";
+        case spv::StorageClassGeneric:
+            return "generic";
+        case spv::StorageClassAtomicCounter:
+            return "atomic counter";
+        case spv::StorageClassImage:
+            return "image";
+        case spv::StorageClassPushConstant:
+            return "push constant";
+        default:
+            return "unknown";
+    }
+}
+
+// Get the value of an integral constant
+unsigned get_constant_value(shader_module const *src, unsigned id) {
+    auto value = src->get_def(id);
+    assert(value != src->end());
+
+    if (value.opcode() != spv::OpConstant) {
+        // TODO: Either ensure that the specialization transform is already performed on a module we're
+        //       considering here, OR -- specialize on the fly now.
+        return 1;
+    }
+
+    return value.word(3);
+}
+
+static void describe_type_inner(std::ostringstream &ss, shader_module const *src, unsigned type) {
+    auto insn = src->get_def(type);
+    assert(insn != src->end());
+
+    switch (insn.opcode()) {
+        case spv::OpTypeBool:
+            ss << "bool";
+            break;
+        case spv::OpTypeInt:
+            ss << (insn.word(3) ? 's' : 'u') << "int" << insn.word(2);
+            break;
+        case spv::OpTypeFloat:
+            ss << "float" << insn.word(2);
+            break;
+        case spv::OpTypeVector:
+            ss << "vec" << insn.word(3) << " of ";
+            describe_type_inner(ss, src, insn.word(2));
+            break;
+        case spv::OpTypeMatrix:
+            ss << "mat" << insn.word(3) << " of ";
+            describe_type_inner(ss, src, insn.word(2));
+            break;
+        case spv::OpTypeArray:
+            ss << "arr[" << get_constant_value(src, insn.word(3)) << "] of ";
+            describe_type_inner(ss, src, insn.word(2));
+            break;
+        case spv::OpTypePointer:
+            ss << "ptr to " << storage_class_name(insn.word(2)) << " ";
+            describe_type_inner(ss, src, insn.word(3));
+            break;
+        case spv::OpTypeStruct: {
+            ss << "struct of (";
+            for (unsigned i = 2; i < insn.len(); i++) {
+                describe_type_inner(ss, src, insn.word(i));
+                if (i == insn.len() - 1) {
+                    ss << ")";
+                } else {
+                    ss << ", ";
+                }
+            }
+            break;
+        }
+        case spv::OpTypeSampler:
+            ss << "sampler";
+            break;
+        case spv::OpTypeSampledImage:
+            ss << "sampler+";
+            describe_type_inner(ss, src, insn.word(2));
+            break;
+        case spv::OpTypeImage:
+            ss << "image(dim=" << insn.word(3) << ", sampled=" << insn.word(7) << ")";
+            break;
+        default:
+            ss << "oddtype";
+            break;
+    }
+}
+
+static std::string describe_type(shader_module const *src, unsigned type) {
+    std::ostringstream ss;
+    describe_type_inner(ss, src, type);
+    return ss.str();
+}
+
+static bool is_narrow_numeric_type(spirv_inst_iter type) {
+    if (type.opcode() != spv::OpTypeInt && type.opcode() != spv::OpTypeFloat) return false;
+    return type.word(2) < 64;
+}
+
+static bool types_match(shader_module const *a, shader_module const *b, unsigned a_type, unsigned b_type, bool a_arrayed,
+                        bool b_arrayed, bool relaxed) {
+    // Walk two type trees together, and complain about differences
+    auto a_insn = a->get_def(a_type);
+    auto b_insn = b->get_def(b_type);
+    assert(a_insn != a->end());
+    assert(b_insn != b->end());
+
+    if (a_arrayed && a_insn.opcode() == spv::OpTypeArray) {
+        return types_match(a, b, a_insn.word(2), b_type, false, b_arrayed, relaxed);
+    }
+
+    if (b_arrayed && b_insn.opcode() == spv::OpTypeArray) {
+        // We probably just found the extra level of arrayness in b_type: compare the type inside it to a_type
+        return types_match(a, b, a_type, b_insn.word(2), a_arrayed, false, relaxed);
+    }
+
+    if (a_insn.opcode() == spv::OpTypeVector && relaxed && is_narrow_numeric_type(b_insn)) {
+        return types_match(a, b, a_insn.word(2), b_type, a_arrayed, b_arrayed, false);
+    }
+
+    if (a_insn.opcode() != b_insn.opcode()) {
+        return false;
+    }
+
+    if (a_insn.opcode() == spv::OpTypePointer) {
+        // Match on pointee type. storage class is expected to differ
+        return types_match(a, b, a_insn.word(3), b_insn.word(3), a_arrayed, b_arrayed, relaxed);
+    }
+
+    if (a_arrayed || b_arrayed) {
+        // If we havent resolved array-of-verts by here, we're not going to.
+        return false;
+    }
+
+    switch (a_insn.opcode()) {
+        case spv::OpTypeBool:
+            return true;
+        case spv::OpTypeInt:
+            // Match on width, signedness
+            return a_insn.word(2) == b_insn.word(2) && a_insn.word(3) == b_insn.word(3);
+        case spv::OpTypeFloat:
+            // Match on width
+            return a_insn.word(2) == b_insn.word(2);
+        case spv::OpTypeVector:
+            // Match on element type, count.
+            if (!types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false)) return false;
+            if (relaxed && is_narrow_numeric_type(a->get_def(a_insn.word(2)))) {
+                return a_insn.word(3) >= b_insn.word(3);
+            } else {
+                return a_insn.word(3) == b_insn.word(3);
+            }
+        case spv::OpTypeMatrix:
+            // Match on element type, count.
+            return types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false) &&
+                a_insn.word(3) == b_insn.word(3);
+        case spv::OpTypeArray:
+            // Match on element type, count. these all have the same layout. we don't get here if b_arrayed. This differs from
+            // vector & matrix types in that the array size is the id of a constant instruction, * not a literal within OpTypeArray
+            return types_match(a, b, a_insn.word(2), b_insn.word(2), a_arrayed, b_arrayed, false) &&
+                get_constant_value(a, a_insn.word(3)) == get_constant_value(b, b_insn.word(3));
+        case spv::OpTypeStruct:
+            // Match on all element types
+        {
+            if (a_insn.len() != b_insn.len()) {
+                return false;  // Structs cannot match if member counts differ
+            }
+
+            for (unsigned i = 2; i < a_insn.len(); i++) {
+                if (!types_match(a, b, a_insn.word(i), b_insn.word(i), a_arrayed, b_arrayed, false)) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+        default:
+            // Remaining types are CLisms, or may not appear in the interfaces we are interested in. Just claim no match.
+            return false;
+    }
+}
+
+static unsigned value_or_default(std::unordered_map<unsigned, unsigned> const &map, unsigned id, unsigned def) {
+    auto it = map.find(id);
+    if (it == map.end())
+        return def;
+    else
+        return it->second;
+}
+
+static unsigned get_locations_consumed_by_type(shader_module const *src, unsigned type, bool strip_array_level) {
+    auto insn = src->get_def(type);
+    assert(insn != src->end());
+
+    switch (insn.opcode()) {
+        case spv::OpTypePointer:
+            // See through the ptr -- this is only ever at the toplevel for graphics shaders we're never actually passing
+            // pointers around.
+            return get_locations_consumed_by_type(src, insn.word(3), strip_array_level);
+        case spv::OpTypeArray:
+            if (strip_array_level) {
+                return get_locations_consumed_by_type(src, insn.word(2), false);
+            } else {
+                return get_constant_value(src, insn.word(3)) * get_locations_consumed_by_type(src, insn.word(2), false);
+            }
+        case spv::OpTypeMatrix:
+            // Num locations is the dimension * element size
+            return insn.word(3) * get_locations_consumed_by_type(src, insn.word(2), false);
+        case spv::OpTypeVector: {
+            auto scalar_type = src->get_def(insn.word(2));
+            auto bit_width =
+                (scalar_type.opcode() == spv::OpTypeInt || scalar_type.opcode() == spv::OpTypeFloat) ? scalar_type.word(2) : 32;
+
+            // Locations are 128-bit wide; 3- and 4-component vectors of 64 bit types require two.
+            return (bit_width * insn.word(3) + 127) / 128;
+        }
+        default:
+            // Everything else is just 1.
+            return 1;
+
+            // TODO: extend to handle 64bit scalar types, whose vectors may need multiple locations.
+    }
+}
+
+static unsigned get_locations_consumed_by_format(VkFormat format) {
+    switch (format) {
+        case VK_FORMAT_R64G64B64A64_SFLOAT:
+        case VK_FORMAT_R64G64B64A64_SINT:
+        case VK_FORMAT_R64G64B64A64_UINT:
+        case VK_FORMAT_R64G64B64_SFLOAT:
+        case VK_FORMAT_R64G64B64_SINT:
+        case VK_FORMAT_R64G64B64_UINT:
+            return 2;
+        default:
+            return 1;
+    }
+}
+
+static unsigned get_format_type(VkFormat fmt) {
+    if (FormatIsSInt(fmt))
+        return FORMAT_TYPE_SINT;
+    if (FormatIsUInt(fmt))
+        return FORMAT_TYPE_UINT;
+    if (FormatIsDepthAndStencil(fmt))
+        return FORMAT_TYPE_FLOAT | FORMAT_TYPE_UINT;
+    if (fmt == VK_FORMAT_UNDEFINED)
+        return 0;
+    // everything else -- UNORM/SNORM/FLOAT/USCALED/SSCALED is all float in the shader.
+    return FORMAT_TYPE_FLOAT;
+}
+
+// characterizes a SPIR-V type appearing in an interface to a FF stage, for comparison to a VkFormat's characterization above.
+static unsigned get_fundamental_type(shader_module const *src, unsigned type) {
+    auto insn = src->get_def(type);
+    assert(insn != src->end());
+
+    switch (insn.opcode()) {
+        case spv::OpTypeInt:
+            return insn.word(3) ? FORMAT_TYPE_SINT : FORMAT_TYPE_UINT;
+        case spv::OpTypeFloat:
+            return FORMAT_TYPE_FLOAT;
+        case spv::OpTypeVector:
+            return get_fundamental_type(src, insn.word(2));
+        case spv::OpTypeMatrix:
+            return get_fundamental_type(src, insn.word(2));
+        case spv::OpTypeArray:
+            return get_fundamental_type(src, insn.word(2));
+        case spv::OpTypePointer:
+            return get_fundamental_type(src, insn.word(3));
+        case spv::OpTypeImage:
+            return get_fundamental_type(src, insn.word(2));
+
+        default:
+            return 0;
+    }
+}
+
+static uint32_t get_shader_stage_id(VkShaderStageFlagBits stage) {
+    uint32_t bit_pos = uint32_t(u_ffs(stage));
+    return bit_pos - 1;
+}
+
+static spirv_inst_iter get_struct_type(shader_module const *src, spirv_inst_iter def, bool is_array_of_verts) {
+    while (true) {
+        if (def.opcode() == spv::OpTypePointer) {
+            def = src->get_def(def.word(3));
+        } else if (def.opcode() == spv::OpTypeArray && is_array_of_verts) {
+            def = src->get_def(def.word(2));
+            is_array_of_verts = false;
+        } else if (def.opcode() == spv::OpTypeStruct) {
+            return def;
+        } else {
+            return src->end();
+        }
+    }
+}
+
+static void collect_interface_block_members(shader_module const *src, std::map<location_t, interface_var> *out,
+                                            std::unordered_map<unsigned, unsigned> const &blocks, bool is_array_of_verts,
+                                            uint32_t id, uint32_t type_id, bool is_patch) {
+    // Walk down the type_id presented, trying to determine whether it's actually an interface block.
+    auto type = get_struct_type(src, src->get_def(type_id), is_array_of_verts && !is_patch);
+    if (type == src->end() || blocks.find(type.word(1)) == blocks.end()) {
+        // This isn't an interface block.
+        return;
+    }
+
+    std::unordered_map<unsigned, unsigned> member_components;
+    std::unordered_map<unsigned, unsigned> member_relaxed_precision;
+
+    // Walk all the OpMemberDecorate for type's result id -- first pass, collect components.
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
+            unsigned member_index = insn.word(2);
+
+            if (insn.word(3) == spv::DecorationComponent) {
+                unsigned component = insn.word(4);
+                member_components[member_index] = component;
+            }
+
+            if (insn.word(3) == spv::DecorationRelaxedPrecision) {
+                member_relaxed_precision[member_index] = 1;
+            }
+        }
+    }
+
+    // Second pass -- produce the output, from Location decorations
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
+            unsigned member_index = insn.word(2);
+            unsigned member_type_id = type.word(2 + member_index);
+
+            if (insn.word(3) == spv::DecorationLocation) {
+                unsigned location = insn.word(4);
+                unsigned num_locations = get_locations_consumed_by_type(src, member_type_id, false);
+                auto component_it = member_components.find(member_index);
+                unsigned component = component_it == member_components.end() ? 0 : component_it->second;
+                bool is_relaxed_precision = member_relaxed_precision.find(member_index) != member_relaxed_precision.end();
+
+                for (unsigned int offset = 0; offset < num_locations; offset++) {
+                    interface_var v = {};
+                    v.id = id;
+                    // TODO: member index in interface_var too?
+                    v.type_id = member_type_id;
+                    v.offset = offset;
+                    v.is_patch = is_patch;
+                    v.is_block_member = true;
+                    v.is_relaxed_precision = is_relaxed_precision;
+                    (*out)[std::make_pair(location + offset, component)] = v;
+                }
+            }
+        }
+    }
+}
+
+static std::map<location_t, interface_var> collect_interface_by_location(shader_module const *src, spirv_inst_iter entrypoint,
+                                                                         spv::StorageClass sinterface, bool is_array_of_verts) {
+    std::unordered_map<unsigned, unsigned> var_locations;
+    std::unordered_map<unsigned, unsigned> var_builtins;
+    std::unordered_map<unsigned, unsigned> var_components;
+    std::unordered_map<unsigned, unsigned> blocks;
+    std::unordered_map<unsigned, unsigned> var_patch;
+    std::unordered_map<unsigned, unsigned> var_relaxed_precision;
+
+    for (auto insn : *src) {
+        // We consider two interface models: SSO rendezvous-by-location, and builtins. Complain about anything that
+        // fits neither model.
+        if (insn.opcode() == spv::OpDecorate) {
+            if (insn.word(2) == spv::DecorationLocation) {
+                var_locations[insn.word(1)] = insn.word(3);
+            }
+
+            if (insn.word(2) == spv::DecorationBuiltIn) {
+                var_builtins[insn.word(1)] = insn.word(3);
+            }
+
+            if (insn.word(2) == spv::DecorationComponent) {
+                var_components[insn.word(1)] = insn.word(3);
+            }
+
+            if (insn.word(2) == spv::DecorationBlock) {
+                blocks[insn.word(1)] = 1;
+            }
+
+            if (insn.word(2) == spv::DecorationPatch) {
+                var_patch[insn.word(1)] = 1;
+            }
+
+            if (insn.word(2) == spv::DecorationRelaxedPrecision) {
+                var_relaxed_precision[insn.word(1)] = 1;
+            }
+        }
+    }
+
+    // TODO: handle grouped decorations
+    // TODO: handle index=1 dual source outputs from FS -- two vars will have the same location, and we DON'T want to clobber.
+
+    // Find the end of the entrypoint's name string. additional zero bytes follow the actual null terminator, to fill out the
+    // rest of the word - so we only need to look at the last byte in the word to determine which word contains the terminator.
+    uint32_t word = 3;
+    while (entrypoint.word(word) & 0xff000000u) {
+        ++word;
+    }
+    ++word;
+
+    std::map<location_t, interface_var> out;
+
+    for (; word < entrypoint.len(); word++) {
+        auto insn = src->get_def(entrypoint.word(word));
+        assert(insn != src->end());
+        assert(insn.opcode() == spv::OpVariable);
+
+        if (insn.word(3) == static_cast<uint32_t>(sinterface)) {
+            unsigned id = insn.word(2);
+            unsigned type = insn.word(1);
+
+            int location = value_or_default(var_locations, id, -1);
+            int builtin = value_or_default(var_builtins, id, -1);
+            unsigned component = value_or_default(var_components, id, 0);  // Unspecified is OK, is 0
+            bool is_patch = var_patch.find(id) != var_patch.end();
+            bool is_relaxed_precision = var_relaxed_precision.find(id) != var_relaxed_precision.end();
+
+            // All variables and interface block members in the Input or Output storage classes must be decorated with either
+            // a builtin or an explicit location.
+            //
+            // TODO: integrate the interface block support here. For now, don't complain -- a valid SPIRV module will only hit
+            // this path for the interface block case, as the individual members of the type are decorated, rather than
+            // variable declarations.
+
+            if (location != -1) {
+                // A user-defined interface variable, with a location. Where a variable occupied multiple locations, emit
+                // one result for each.
+                unsigned num_locations = get_locations_consumed_by_type(src, type, is_array_of_verts && !is_patch);
+                for (unsigned int offset = 0; offset < num_locations; offset++) {
+                    interface_var v = {};
+                    v.id = id;
+                    v.type_id = type;
+                    v.offset = offset;
+                    v.is_patch = is_patch;
+                    v.is_relaxed_precision = is_relaxed_precision;
+                    out[std::make_pair(location + offset, component)] = v;
+                }
+            } else if (builtin == -1) {
+                // An interface block instance
+                collect_interface_block_members(src, &out, blocks, is_array_of_verts, id, type, is_patch);
+            }
+        }
+    }
+
+    return out;
+}
+
+static std::vector<std::pair<uint32_t, interface_var>> collect_interface_by_input_attachment_index(
+    shader_module const *src, std::unordered_set<uint32_t> const &accessible_ids) {
+    std::vector<std::pair<uint32_t, interface_var>> out;
+
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpDecorate) {
+            if (insn.word(2) == spv::DecorationInputAttachmentIndex) {
+                auto attachment_index = insn.word(3);
+                auto id = insn.word(1);
+
+                if (accessible_ids.count(id)) {
+                    auto def = src->get_def(id);
+                    assert(def != src->end());
+
+                    if (def.opcode() == spv::OpVariable && insn.word(3) == spv::StorageClassUniformConstant) {
+                        auto num_locations = get_locations_consumed_by_type(src, def.word(1), false);
+                        for (unsigned int offset = 0; offset < num_locations; offset++) {
+                            interface_var v = {};
+                            v.id = id;
+                            v.type_id = def.word(1);
+                            v.offset = offset;
+                            out.emplace_back(attachment_index + offset, v);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return out;
+}
+
+static std::vector<std::pair<descriptor_slot_t, interface_var>> collect_interface_by_descriptor_slot(
+    debug_report_data const *report_data, shader_module const *src, std::unordered_set<uint32_t> const &accessible_ids) {
+    std::unordered_map<unsigned, unsigned> var_sets;
+    std::unordered_map<unsigned, unsigned> var_bindings;
+
+    for (auto insn : *src) {
+        // All variables in the Uniform or UniformConstant storage classes are required to be decorated with both
+        // DecorationDescriptorSet and DecorationBinding.
+        if (insn.opcode() == spv::OpDecorate) {
+            if (insn.word(2) == spv::DecorationDescriptorSet) {
+                var_sets[insn.word(1)] = insn.word(3);
+            }
+
+            if (insn.word(2) == spv::DecorationBinding) {
+                var_bindings[insn.word(1)] = insn.word(3);
+            }
+        }
+    }
+
+    std::vector<std::pair<descriptor_slot_t, interface_var>> out;
+
+    for (auto id : accessible_ids) {
+        auto insn = src->get_def(id);
+        assert(insn != src->end());
+
+        if (insn.opcode() == spv::OpVariable &&
+            (insn.word(3) == spv::StorageClassUniform || insn.word(3) == spv::StorageClassUniformConstant)) {
+            unsigned set = value_or_default(var_sets, insn.word(2), 0);
+            unsigned binding = value_or_default(var_bindings, insn.word(2), 0);
+
+            interface_var v = {};
+            v.id = insn.word(2);
+            v.type_id = insn.word(1);
+            out.emplace_back(std::make_pair(set, binding), v);
+        }
+    }
+
+    return out;
+}
+
+
+
+static bool validate_vi_consistency(debug_report_data const *report_data, VkPipelineVertexInputStateCreateInfo const *vi) {
+    // Walk the binding descriptions, which describe the step rate and stride of each vertex buffer.  Each binding should
+    // be specified only once.
+    std::unordered_map<uint32_t, VkVertexInputBindingDescription const *> bindings;
+    bool skip = false;
+
+    for (unsigned i = 0; i < vi->vertexBindingDescriptionCount; i++) {
+        auto desc = &vi->pVertexBindingDescriptions[i];
+        auto &binding = bindings[desc->binding];
+        if (binding) {
+            // TODO: VALIDATION_ERROR_096005cc perhaps?
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_INCONSISTENT_VI, "SC", "Duplicate vertex input binding descriptions for binding %d",
+                            desc->binding);
+        } else {
+            binding = desc;
+        }
+    }
+
+    return skip;
+}
+
+static bool validate_vi_against_vs_inputs(debug_report_data const *report_data, VkPipelineVertexInputStateCreateInfo const *vi,
+                                          shader_module const *vs, spirv_inst_iter entrypoint) {
+    bool skip = false;
+
+    auto inputs = collect_interface_by_location(vs, entrypoint, spv::StorageClassInput, false);
+
+    // Build index by location
+    std::map<uint32_t, VkVertexInputAttributeDescription const *> attribs;
+    if (vi) {
+        for (unsigned i = 0; i < vi->vertexAttributeDescriptionCount; i++) {
+            auto num_locations = get_locations_consumed_by_format(vi->pVertexAttributeDescriptions[i].format);
+            for (auto j = 0u; j < num_locations; j++) {
+                attribs[vi->pVertexAttributeDescriptions[i].location + j] = &vi->pVertexAttributeDescriptions[i];
+            }
+        }
+    }
+
+    auto it_a = attribs.begin();
+    auto it_b = inputs.begin();
+    bool used = false;
+
+    while ((attribs.size() > 0 && it_a != attribs.end()) || (inputs.size() > 0 && it_b != inputs.end())) {
+        bool a_at_end = attribs.size() == 0 || it_a == attribs.end();
+        bool b_at_end = inputs.size() == 0 || it_b == inputs.end();
+        auto a_first = a_at_end ? 0 : it_a->first;
+        auto b_first = b_at_end ? 0 : it_b->first.first;
+        if (!a_at_end && (b_at_end || a_first < b_first)) {
+            if (!used && log_msg(report_data, VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT,
+                                 0, __LINE__, SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
+                                 "Vertex attribute at location %d not consumed by vertex shader", a_first)) {
+                skip = true;
+            }
+            used = false;
+            it_a++;
+        } else if (!b_at_end && (a_at_end || b_first < a_first)) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
+                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "Vertex shader consumes input at location %d but not provided",
+                            b_first);
+            it_b++;
+        } else {
+            unsigned attrib_type = get_format_type(it_a->second->format);
+            unsigned input_type = get_fundamental_type(vs, it_b->second.type_id);
+
+            // Type checking
+            if (!(attrib_type & input_type)) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
+                                "Attribute type of `%s` at location %d does not match vertex shader input type of `%s`",
+                                string_VkFormat(it_a->second->format), a_first, describe_type(vs, it_b->second.type_id).c_str());
+            }
+
+            // OK!
+            used = true;
+            it_b++;
+        }
+    }
+
+    return skip;
+}
+
+static bool validate_fs_outputs_against_render_pass(debug_report_data const *report_data, shader_module const *fs,
+                                                    spirv_inst_iter entrypoint, VkRenderPassCreateInfo const *rpci,
+                                                    uint32_t subpass_index) {
+    std::map<uint32_t, VkFormat> color_attachments;
+    auto subpass = rpci->pSubpasses[subpass_index];
+    for (auto i = 0u; i < subpass.colorAttachmentCount; ++i) {
+        uint32_t attachment = subpass.pColorAttachments[i].attachment;
+        if (attachment == VK_ATTACHMENT_UNUSED) continue;
+        if (rpci->pAttachments[attachment].format != VK_FORMAT_UNDEFINED) {
+            color_attachments[i] = rpci->pAttachments[attachment].format;
+        }
+    }
+
+    bool skip = false;
+
+    // TODO: dual source blend index (spv::DecIndex, zero if not provided)
+
+    auto outputs = collect_interface_by_location(fs, entrypoint, spv::StorageClassOutput, false);
+
+    auto it_a = outputs.begin();
+    auto it_b = color_attachments.begin();
+
+    // Walk attachment list and outputs together
+
+    while ((outputs.size() > 0 && it_a != outputs.end()) || (color_attachments.size() > 0 && it_b != color_attachments.end())) {
+        bool a_at_end = outputs.size() == 0 || it_a == outputs.end();
+        bool b_at_end = color_attachments.size() == 0 || it_b == color_attachments.end();
+
+        if (!a_at_end && (b_at_end || it_a->first.first < it_b->first)) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
+                            "fragment shader writes to output location %d with no matching attachment", it_a->first.first);
+            it_a++;
+        } else if (!b_at_end && (a_at_end || it_a->first.first > it_b->first)) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "Attachment %d not written by fragment shader", it_b->first);
+            it_b++;
+        } else {
+            unsigned output_type = get_fundamental_type(fs, it_a->second.type_id);
+            unsigned att_type = get_format_type(it_b->second);
+
+            // Type checking
+            if (!(output_type & att_type)) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
+                                "Attachment %d of type `%s` does not match fragment shader output type of `%s`", it_b->first,
+                                string_VkFormat(it_b->second), describe_type(fs, it_a->second.type_id).c_str());
+            }
+
+            // OK!
+            it_a++;
+            it_b++;
+        }
+    }
+
+    return skip;
+}
+
+// For some analyses, we need to know about all ids referenced by the static call tree of a particular entrypoint. This is
+// important for identifying the set of shader resources actually used by an entrypoint, for example.
+// Note: we only explore parts of the image which might actually contain ids we care about for the above analyses.
+//  - NOT the shader input/output interfaces.
+//
+// TODO: The set of interesting opcodes here was determined by eyeballing the SPIRV spec. It might be worth
+// converting parts of this to be generated from the machine-readable spec instead.
+static std::unordered_set<uint32_t> mark_accessible_ids(shader_module const *src, spirv_inst_iter entrypoint) {
+    std::unordered_set<uint32_t> ids;
+    std::unordered_set<uint32_t> worklist;
+    worklist.insert(entrypoint.word(2));
+
+    while (!worklist.empty()) {
+        auto id_iter = worklist.begin();
+        auto id = *id_iter;
+        worklist.erase(id_iter);
+
+        auto insn = src->get_def(id);
+        if (insn == src->end()) {
+            // ID is something we didn't collect in build_def_index. that's OK -- we'll stumble across all kinds of things here
+            // that we may not care about.
+            continue;
+        }
+
+        // Try to add to the output set
+        if (!ids.insert(id).second) {
+            continue;  // If we already saw this id, we don't want to walk it again.
+        }
+
+        switch (insn.opcode()) {
+            case spv::OpFunction:
+                // Scan whole body of the function, enlisting anything interesting
+                while (++insn, insn.opcode() != spv::OpFunctionEnd) {
+                    switch (insn.opcode()) {
+                        case spv::OpLoad:
+                        case spv::OpAtomicLoad:
+                        case spv::OpAtomicExchange:
+                        case spv::OpAtomicCompareExchange:
+                        case spv::OpAtomicCompareExchangeWeak:
+                        case spv::OpAtomicIIncrement:
+                        case spv::OpAtomicIDecrement:
+                        case spv::OpAtomicIAdd:
+                        case spv::OpAtomicISub:
+                        case spv::OpAtomicSMin:
+                        case spv::OpAtomicUMin:
+                        case spv::OpAtomicSMax:
+                        case spv::OpAtomicUMax:
+                        case spv::OpAtomicAnd:
+                        case spv::OpAtomicOr:
+                        case spv::OpAtomicXor:
+                            worklist.insert(insn.word(3));  // ptr
+                            break;
+                        case spv::OpStore:
+                        case spv::OpAtomicStore:
+                            worklist.insert(insn.word(1));  // ptr
+                            break;
+                        case spv::OpAccessChain:
+                        case spv::OpInBoundsAccessChain:
+                            worklist.insert(insn.word(3));  // base ptr
+                            break;
+                        case spv::OpSampledImage:
+                        case spv::OpImageSampleImplicitLod:
+                        case spv::OpImageSampleExplicitLod:
+                        case spv::OpImageSampleDrefImplicitLod:
+                        case spv::OpImageSampleDrefExplicitLod:
+                        case spv::OpImageSampleProjImplicitLod:
+                        case spv::OpImageSampleProjExplicitLod:
+                        case spv::OpImageSampleProjDrefImplicitLod:
+                        case spv::OpImageSampleProjDrefExplicitLod:
+                        case spv::OpImageFetch:
+                        case spv::OpImageGather:
+                        case spv::OpImageDrefGather:
+                        case spv::OpImageRead:
+                        case spv::OpImage:
+                        case spv::OpImageQueryFormat:
+                        case spv::OpImageQueryOrder:
+                        case spv::OpImageQuerySizeLod:
+                        case spv::OpImageQuerySize:
+                        case spv::OpImageQueryLod:
+                        case spv::OpImageQueryLevels:
+                        case spv::OpImageQuerySamples:
+                        case spv::OpImageSparseSampleImplicitLod:
+                        case spv::OpImageSparseSampleExplicitLod:
+                        case spv::OpImageSparseSampleDrefImplicitLod:
+                        case spv::OpImageSparseSampleDrefExplicitLod:
+                        case spv::OpImageSparseSampleProjImplicitLod:
+                        case spv::OpImageSparseSampleProjExplicitLod:
+                        case spv::OpImageSparseSampleProjDrefImplicitLod:
+                        case spv::OpImageSparseSampleProjDrefExplicitLod:
+                        case spv::OpImageSparseFetch:
+                        case spv::OpImageSparseGather:
+                        case spv::OpImageSparseDrefGather:
+                        case spv::OpImageTexelPointer:
+                            worklist.insert(insn.word(3));  // Image or sampled image
+                            break;
+                        case spv::OpImageWrite:
+                            worklist.insert(insn.word(1));  // Image -- different operand order to above
+                            break;
+                        case spv::OpFunctionCall:
+                            for (uint32_t i = 3; i < insn.len(); i++) {
+                                worklist.insert(insn.word(i));  // fn itself, and all args
+                            }
+                            break;
+
+                        case spv::OpExtInst:
+                            for (uint32_t i = 5; i < insn.len(); i++) {
+                                worklist.insert(insn.word(i));  // Operands to ext inst
+                            }
+                            break;
+                    }
+                }
+                break;
+        }
+    }
+
+    return ids;
+}
+
+static bool validate_push_constant_block_against_pipeline(debug_report_data const *report_data,
+                                                          std::vector<VkPushConstantRange> const *push_constant_ranges,
+                                                          shader_module const *src, spirv_inst_iter type,
+                                                          VkShaderStageFlagBits stage) {
+    bool skip = false;
+
+    // Strip off ptrs etc
+    type = get_struct_type(src, type, false);
+    assert(type != src->end());
+
+    // Validate directly off the offsets. this isn't quite correct for arrays and matrices, but is a good first step.
+    // TODO: arrays, matrices, weird sizes
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpMemberDecorate && insn.word(1) == type.word(1)) {
+            if (insn.word(3) == spv::DecorationOffset) {
+                unsigned offset = insn.word(4);
+                auto size = 4;  // Bytes; TODO: calculate this based on the type
+
+                bool found_range = false;
+                for (auto const &range : *push_constant_ranges) {
+                    if (range.offset <= offset && range.offset + range.size >= offset + size) {
+                        found_range = true;
+
+                        if ((range.stageFlags & stage) == 0) {
+                            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
+                                            __LINE__, SHADER_CHECKER_PUSH_CONSTANT_NOT_ACCESSIBLE_FROM_STAGE, "SC",
+                                            "Push constant range covering variable starting at "
+                                                "offset %u not accessible from stage %s",
+                                            offset, string_VkShaderStageFlagBits(stage));
+                        }
+
+                        break;
+                    }
+                }
+
+                if (!found_range) {
+                    skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
+                                    __LINE__, SHADER_CHECKER_PUSH_CONSTANT_OUT_OF_RANGE, "SC",
+                                    "Push constant range covering variable starting at "
+                                        "offset %u not declared in layout",
+                                    offset);
+                }
+            }
+        }
+    }
+
+    return skip;
+}
+
+static bool validate_push_constant_usage(debug_report_data const *report_data,
+                                         std::vector<VkPushConstantRange> const *push_constant_ranges, shader_module const *src,
+                                         std::unordered_set<uint32_t> accessible_ids, VkShaderStageFlagBits stage) {
+    bool skip = false;
+
+    for (auto id : accessible_ids) {
+        auto def_insn = src->get_def(id);
+        if (def_insn.opcode() == spv::OpVariable && def_insn.word(3) == spv::StorageClassPushConstant) {
+            skip |= validate_push_constant_block_against_pipeline(report_data, push_constant_ranges, src,
+                                                                  src->get_def(def_insn.word(1)), stage);
+        }
+    }
+
+    return skip;
+}
+
+// Validate that data for each specialization entry is fully contained within the buffer.
+static bool validate_specialization_offsets(debug_report_data const *report_data, VkPipelineShaderStageCreateInfo const *info) {
+    bool skip = false;
+
+    VkSpecializationInfo const *spec = info->pSpecializationInfo;
+
+    if (spec) {
+        for (auto i = 0u; i < spec->mapEntryCount; i++) {
+            // TODO: This is a good place for VALIDATION_ERROR_1360060a.
+            if (spec->pMapEntries[i].offset + spec->pMapEntries[i].size > spec->dataSize) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
+                                VALIDATION_ERROR_1360060c, "SC",
+                                "Specialization entry %u (for constant id %u) references memory outside provided "
+                                    "specialization data (bytes %u.." PRINTF_SIZE_T_SPECIFIER "; " PRINTF_SIZE_T_SPECIFIER
+                " bytes provided). %s.",
+                    i, spec->pMapEntries[i].constantID, spec->pMapEntries[i].offset,
+                    spec->pMapEntries[i].offset + spec->pMapEntries[i].size - 1, spec->dataSize,
+                    validation_error_map[VALIDATION_ERROR_1360060c]);
+            }
+        }
+    }
+
+    return skip;
+}
+
+static bool descriptor_type_match(shader_module const *module, uint32_t type_id, VkDescriptorType descriptor_type,
+                                  unsigned &descriptor_count) {
+    auto type = module->get_def(type_id);
+
+    descriptor_count = 1;
+
+    // Strip off any array or ptrs. Where we remove array levels, adjust the  descriptor count for each dimension.
+    while (type.opcode() == spv::OpTypeArray || type.opcode() == spv::OpTypePointer) {
+        if (type.opcode() == spv::OpTypeArray) {
+            descriptor_count *= get_constant_value(module, type.word(3));
+            type = module->get_def(type.word(2));
+        } else {
+            type = module->get_def(type.word(3));
+        }
+    }
+
+    switch (type.opcode()) {
+        case spv::OpTypeStruct: {
+            for (auto insn : *module) {
+                if (insn.opcode() == spv::OpDecorate && insn.word(1) == type.word(1)) {
+                    if (insn.word(2) == spv::DecorationBlock) {
+                        return descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER ||
+                            descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
+                    } else if (insn.word(2) == spv::DecorationBufferBlock) {
+                        return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER ||
+                            descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC;
+                    }
+                }
+            }
+
+            // Invalid
+            return false;
+        }
+
+        case spv::OpTypeSampler:
+            return descriptor_type == VK_DESCRIPTOR_TYPE_SAMPLER || descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+
+        case spv::OpTypeSampledImage:
+            if (descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER) {
+                // Slight relaxation for some GLSL historical madness: samplerBuffer doesn't really have a sampler, and a texel
+                // buffer descriptor doesn't really provide one. Allow this slight mismatch.
+                auto image_type = module->get_def(type.word(2));
+                auto dim = image_type.word(3);
+                auto sampled = image_type.word(7);
+                return dim == spv::DimBuffer && sampled == 1;
+            }
+            return descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+
+        case spv::OpTypeImage: {
+            // Many descriptor types backing image types-- depends on dimension and whether the image will be used with a sampler.
+            // SPIRV for Vulkan requires that sampled be 1 or 2 -- leaving the decision to runtime is unacceptable.
+            auto dim = type.word(3);
+            auto sampled = type.word(7);
+
+            if (dim == spv::DimSubpassData) {
+                return descriptor_type == VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT;
+            } else if (dim == spv::DimBuffer) {
+                if (sampled == 1) {
+                    return descriptor_type == VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER;
+                } else {
+                    return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER;
+                }
+            } else if (sampled == 1) {
+                return descriptor_type == VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE ||
+                    descriptor_type == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+            } else {
+                return descriptor_type == VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
+            }
+        }
+
+            // We shouldn't really see any other junk types -- but if we do, they're a mismatch.
+        default:
+            return false;  // Mismatch
+    }
+}
+
+static bool require_feature(debug_report_data const *report_data, VkBool32 feature, char const *feature_name) {
+    if (!feature) {
+        if (log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                    SHADER_CHECKER_FEATURE_NOT_ENABLED, "SC",
+                    "Shader requires VkPhysicalDeviceFeatures::%s but is not "
+                        "enabled on the device",
+                    feature_name)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static bool require_extension(debug_report_data const *report_data, bool extension, char const *extension_name) {
+    if (!extension) {
+        if (log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                    SHADER_CHECKER_FEATURE_NOT_ENABLED, "SC",
+                    "Shader requires extension %s but is not "
+                        "enabled on the device",
+                    extension_name)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static bool validate_shader_capabilities(layer_data *dev_data, shader_module const *src) {
+    bool skip = false;
+
+    auto report_data = GetReportData(dev_data);
+    auto const & enabledFeatures = GetEnabledFeatures(dev_data);
+    auto const & extensions = GetEnabledExtensions(dev_data);
+
+    struct CapabilityInfo {
+        char const *name;
+        VkBool32 const VkPhysicalDeviceFeatures::*feature;
+        bool const DeviceExtensions::*extension;
+    };
+
+    using F = VkPhysicalDeviceFeatures;
+    using E = DeviceExtensions;
+
+    // clang-format off
+    static const std::unordered_map<uint32_t, CapabilityInfo> capabilities = {
+        // Capabilities always supported by a Vulkan 1.0 implementation -- no
+        // feature bits.
+        {spv::CapabilityMatrix, {nullptr}},
+        {spv::CapabilityShader, {nullptr}},
+        {spv::CapabilityInputAttachment, {nullptr}},
+        {spv::CapabilitySampled1D, {nullptr}},
+        {spv::CapabilityImage1D, {nullptr}},
+        {spv::CapabilitySampledBuffer, {nullptr}},
+        {spv::CapabilityImageQuery, {nullptr}},
+        {spv::CapabilityDerivativeControl, {nullptr}},
+
+        // Capabilities that are optionally supported, but require a feature to
+        // be enabled on the device
+        {spv::CapabilityGeometry, {"geometryShader", &F::geometryShader}},
+        {spv::CapabilityTessellation, {"tessellationShader", &F::tessellationShader}},
+        {spv::CapabilityFloat64, {"shaderFloat64", &F::shaderFloat64}},
+        {spv::CapabilityInt64, {"shaderInt64", &F::shaderInt64}},
+        {spv::CapabilityTessellationPointSize, {"shaderTessellationAndGeometryPointSize", &F::shaderTessellationAndGeometryPointSize}},
+        {spv::CapabilityGeometryPointSize, {"shaderTessellationAndGeometryPointSize", &F::shaderTessellationAndGeometryPointSize}},
+        {spv::CapabilityImageGatherExtended, {"shaderImageGatherExtended", &F::shaderImageGatherExtended}},
+        {spv::CapabilityStorageImageMultisample, {"shaderStorageImageMultisample", &F::shaderStorageImageMultisample}},
+        {spv::CapabilityUniformBufferArrayDynamicIndexing, {"shaderUniformBufferArrayDynamicIndexing", &F::shaderUniformBufferArrayDynamicIndexing}},
+        {spv::CapabilitySampledImageArrayDynamicIndexing, {"shaderSampledImageArrayDynamicIndexing", &F::shaderSampledImageArrayDynamicIndexing}},
+        {spv::CapabilityStorageBufferArrayDynamicIndexing, {"shaderStorageBufferArrayDynamicIndexing", &F::shaderStorageBufferArrayDynamicIndexing}},
+        {spv::CapabilityStorageImageArrayDynamicIndexing, {"shaderStorageImageArrayDynamicIndexing", &F::shaderStorageBufferArrayDynamicIndexing}},
+        {spv::CapabilityClipDistance, {"shaderClipDistance", &F::shaderClipDistance}},
+        {spv::CapabilityCullDistance, {"shaderCullDistance", &F::shaderCullDistance}},
+        {spv::CapabilityImageCubeArray, {"imageCubeArray", &F::imageCubeArray}},
+        {spv::CapabilitySampleRateShading, {"sampleRateShading", &F::sampleRateShading}},
+        {spv::CapabilitySparseResidency, {"shaderResourceResidency", &F::shaderResourceResidency}},
+        {spv::CapabilityMinLod, {"shaderResourceMinLod", &F::shaderResourceMinLod}},
+        {spv::CapabilitySampledCubeArray, {"imageCubeArray", &F::imageCubeArray}},
+        {spv::CapabilityImageMSArray, {"shaderStorageImageMultisample", &F::shaderStorageImageMultisample}},
+        {spv::CapabilityStorageImageExtendedFormats, {"shaderStorageImageExtendedFormats", &F::shaderStorageImageExtendedFormats}},
+        {spv::CapabilityInterpolationFunction, {"sampleRateShading", &F::sampleRateShading}},
+        {spv::CapabilityStorageImageReadWithoutFormat, {"shaderStorageImageReadWithoutFormat", &F::shaderStorageImageReadWithoutFormat}},
+        {spv::CapabilityStorageImageWriteWithoutFormat, {"shaderStorageImageWriteWithoutFormat", &F::shaderStorageImageWriteWithoutFormat}},
+        {spv::CapabilityMultiViewport, {"multiViewport", &F::multiViewport}},
+
+        // Capabilities that require an extension
+        {spv::CapabilityDrawParameters, {VK_KHR_SHADER_DRAW_PARAMETERS_EXTENSION_NAME, nullptr, &E::vk_khr_shader_draw_parameters}},
+        {spv::CapabilityGeometryShaderPassthroughNV, {VK_NV_GEOMETRY_SHADER_PASSTHROUGH_EXTENSION_NAME, nullptr, &E::vk_nv_geometry_shader_passthrough}},
+        {spv::CapabilitySampleMaskOverrideCoverageNV, {VK_NV_SAMPLE_MASK_OVERRIDE_COVERAGE_EXTENSION_NAME, nullptr, &E::vk_nv_sample_mask_override_coverage}},
+        {spv::CapabilityShaderViewportIndexLayerNV, {VK_NV_VIEWPORT_ARRAY2_EXTENSION_NAME, nullptr, &E::vk_nv_viewport_array2}},
+        {spv::CapabilityShaderViewportMaskNV, {VK_NV_VIEWPORT_ARRAY2_EXTENSION_NAME, nullptr, &E::vk_nv_viewport_array2}},
+        {spv::CapabilitySubgroupBallotKHR, {VK_EXT_SHADER_SUBGROUP_BALLOT_EXTENSION_NAME, nullptr, &E::vk_ext_shader_subgroup_ballot }},
+        {spv::CapabilitySubgroupVoteKHR, {VK_EXT_SHADER_SUBGROUP_VOTE_EXTENSION_NAME, nullptr, &E::vk_ext_shader_subgroup_vote }},
+    };
+    // clang-format on
+
+    for (auto insn : *src) {
+        if (insn.opcode() == spv::OpCapability) {
+            auto it = capabilities.find(insn.word(1));
+            if (it != capabilities.end()) {
+                if (it->second.feature) {
+                    skip |= require_feature(report_data, enabledFeatures->*(it->second.feature), it->second.name);
+                }
+                if (it->second.extension) {
+                    skip |= require_extension(report_data, extensions->*(it->second.extension), it->second.name);
+                }
+            }
+        }
+    }
+
+    return skip;
+}
+
+static uint32_t descriptor_type_to_reqs(shader_module const *module, uint32_t type_id) {
+    auto type = module->get_def(type_id);
+
+    while (true) {
+        switch (type.opcode()) {
+            case spv::OpTypeArray:
+            case spv::OpTypeSampledImage:
+                type = module->get_def(type.word(2));
+                break;
+            case spv::OpTypePointer:
+                type = module->get_def(type.word(3));
+                break;
+            case spv::OpTypeImage: {
+                auto dim = type.word(3);
+                auto arrayed = type.word(5);
+                auto msaa = type.word(6);
+
+                switch (dim) {
+                    case spv::Dim1D:
+                        return arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_1D_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_1D;
+                    case spv::Dim2D:
+                        return (msaa ? DESCRIPTOR_REQ_MULTI_SAMPLE : DESCRIPTOR_REQ_SINGLE_SAMPLE) |
+                            (arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_2D_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_2D);
+                    case spv::Dim3D:
+                        return DESCRIPTOR_REQ_VIEW_TYPE_3D;
+                    case spv::DimCube:
+                        return arrayed ? DESCRIPTOR_REQ_VIEW_TYPE_CUBE_ARRAY : DESCRIPTOR_REQ_VIEW_TYPE_CUBE;
+                    case spv::DimSubpassData:
+                        return msaa ? DESCRIPTOR_REQ_MULTI_SAMPLE : DESCRIPTOR_REQ_SINGLE_SAMPLE;
+                    default:  // buffer, etc.
+                        return 0;
+                }
+            }
+            default:
+                return 0;
+        }
+    }
+}
+
+// For given pipelineLayout verify that the set_layout_node at slot.first
+//  has the requested binding at slot.second and return ptr to that binding
+static VkDescriptorSetLayoutBinding const *get_descriptor_binding(PIPELINE_LAYOUT_NODE const *pipelineLayout,
+                                                                  descriptor_slot_t slot) {
+    if (!pipelineLayout) return nullptr;
+
+    if (slot.first >= pipelineLayout->set_layouts.size()) return nullptr;
+
+    return pipelineLayout->set_layouts[slot.first]->GetDescriptorSetLayoutBindingPtrFromBinding(slot.second);
+}
+
+
+static bool validate_pipeline_shader_stage(
+    layer_data *dev_data, VkPipelineShaderStageCreateInfo const *pStage, PIPELINE_STATE *pipeline,
+    shader_module const **out_module, spirv_inst_iter *out_entrypoint) {
+    bool skip = false;
+    auto module = *out_module = GetShaderModuleState(dev_data, pStage->module);
+    auto report_data = GetReportData(dev_data);
+
+    if (!module->has_valid_spirv) return false;
+
+    // Find the entrypoint
+    auto entrypoint = *out_entrypoint = find_entrypoint(module, pStage->pName, pStage->stage);
+    if (entrypoint == module->end()) {
+        if (log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                    VALIDATION_ERROR_10600586, "SC", "No entrypoint found named `%s` for stage %s. %s.", pStage->pName,
+                    string_VkShaderStageFlagBits(pStage->stage), validation_error_map[VALIDATION_ERROR_10600586])) {
+            return true;  // no point continuing beyond here, any analysis is just going to be garbage.
+        }
+    }
+
+    // Validate shader capabilities against enabled device features
+    skip |= validate_shader_capabilities(dev_data, module);
+
+    // Mark accessible ids
+    auto accessible_ids = mark_accessible_ids(module, entrypoint);
+
+    // Validate descriptor set layout against what the entrypoint actually uses
+    auto descriptor_uses = collect_interface_by_descriptor_slot(report_data, module, accessible_ids);
+
+    auto pipelineLayout = pipeline->pipeline_layout;
+
+    skip |= validate_specialization_offsets(report_data, pStage);
+    skip |= validate_push_constant_usage(report_data, &pipelineLayout.push_constant_ranges, module, accessible_ids, pStage->stage);
+
+    // Validate descriptor use
+    for (auto use : descriptor_uses) {
+        // While validating shaders capture which slots are used by the pipeline
+        auto &reqs = pipeline->active_slots[use.first.first][use.first.second];
+        reqs = descriptor_req(reqs | descriptor_type_to_reqs(module, use.second.type_id));
+
+        // Verify given pipelineLayout has requested setLayout with requested binding
+        const auto &binding = get_descriptor_binding(&pipelineLayout, use.first);
+        unsigned required_descriptor_count;
+
+        if (!binding) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_MISSING_DESCRIPTOR, "SC",
+                            "Shader uses descriptor slot %u.%u (used as type `%s`) but not declared in pipeline layout",
+                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str());
+        } else if (~binding->stageFlags & pStage->stage) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
+                            SHADER_CHECKER_DESCRIPTOR_NOT_ACCESSIBLE_FROM_STAGE, "SC",
+                            "Shader uses descriptor slot %u.%u (used "
+                                "as type `%s`) but descriptor not "
+                                "accessible from stage %s",
+                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str(),
+                            string_VkShaderStageFlagBits(pStage->stage));
+        } else if (!descriptor_type_match(module, use.second.type_id, binding->descriptorType, required_descriptor_count)) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_DESCRIPTOR_TYPE_MISMATCH, "SC",
+                            "Type mismatch on descriptor slot "
+                                "%u.%u (used as type `%s`) but "
+                                "descriptor of type %s",
+                            use.first.first, use.first.second, describe_type(module, use.second.type_id).c_str(),
+                            string_VkDescriptorType(binding->descriptorType));
+        } else if (binding->descriptorCount < required_descriptor_count) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_DESCRIPTOR_TYPE_MISMATCH, "SC",
+                            "Shader expects at least %u descriptors for binding %u.%u (used as type `%s`) but only %u provided",
+                            required_descriptor_count, use.first.first, use.first.second,
+                            describe_type(module, use.second.type_id).c_str(), binding->descriptorCount);
+        }
+    }
+
+    // Validate use of input attachments against subpass structure
+    if (pStage->stage == VK_SHADER_STAGE_FRAGMENT_BIT) {
+        auto input_attachment_uses = collect_interface_by_input_attachment_index(module, accessible_ids);
+
+        auto rpci = pipeline->render_pass_ci.ptr();
+        auto subpass = pipeline->graphicsPipelineCI.subpass;
+
+        for (auto use : input_attachment_uses) {
+            auto input_attachments = rpci->pSubpasses[subpass].pInputAttachments;
+            auto index = (input_attachments && use.first < rpci->pSubpasses[subpass].inputAttachmentCount)
+                         ? input_attachments[use.first].attachment
+                         : VK_ATTACHMENT_UNUSED;
+
+            if (index == VK_ATTACHMENT_UNUSED) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                                SHADER_CHECKER_MISSING_INPUT_ATTACHMENT, "SC",
+                                "Shader consumes input attachment index %d but not provided in subpass", use.first);
+            } else if (!(get_format_type(rpci->pAttachments[index].format) & get_fundamental_type(module, use.second.type_id))) {
+                skip |=
+                    log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_INPUT_ATTACHMENT_TYPE_MISMATCH, "SC",
+                            "Subpass input attachment %u format of %s does not match type used in shader `%s`", use.first,
+                            string_VkFormat(rpci->pAttachments[index].format), describe_type(module, use.second.type_id).c_str());
+            }
+        }
+    }
+
+    return skip;
+}
+
+static bool validate_interface_between_stages(debug_report_data const *report_data, shader_module const *producer,
+                                              spirv_inst_iter producer_entrypoint, shader_stage_attributes const *producer_stage,
+                                              shader_module const *consumer, spirv_inst_iter consumer_entrypoint,
+                                              shader_stage_attributes const *consumer_stage) {
+    bool skip = false;
+
+    auto outputs =
+        collect_interface_by_location(producer, producer_entrypoint, spv::StorageClassOutput, producer_stage->arrayed_output);
+    auto inputs =
+        collect_interface_by_location(consumer, consumer_entrypoint, spv::StorageClassInput, consumer_stage->arrayed_input);
+
+    auto a_it = outputs.begin();
+    auto b_it = inputs.begin();
+
+    // Maps sorted by key (location); walk them together to find mismatches
+    while ((outputs.size() > 0 && a_it != outputs.end()) || (inputs.size() && b_it != inputs.end())) {
+        bool a_at_end = outputs.size() == 0 || a_it == outputs.end();
+        bool b_at_end = inputs.size() == 0 || b_it == inputs.end();
+        auto a_first = a_at_end ? std::make_pair(0u, 0u) : a_it->first;
+        auto b_first = b_at_end ? std::make_pair(0u, 0u) : b_it->first;
+
+        if (b_at_end || ((!a_at_end) && (a_first < b_first))) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0,
+                            __LINE__, SHADER_CHECKER_OUTPUT_NOT_CONSUMED, "SC",
+                            "%s writes to output location %u.%u which is not consumed by %s", producer_stage->name, a_first.first,
+                            a_first.second, consumer_stage->name);
+            a_it++;
+        } else if (a_at_end || a_first > b_first) {
+            skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                            SHADER_CHECKER_INPUT_NOT_PRODUCED, "SC", "%s consumes input location %u.%u which is not written by %s",
+                            consumer_stage->name, b_first.first, b_first.second, producer_stage->name);
+            b_it++;
+        } else {
+            // subtleties of arrayed interfaces:
+            // - if is_patch, then the member is not arrayed, even though the interface may be.
+            // - if is_block_member, then the extra array level of an arrayed interface is not
+            //   expressed in the member type -- it's expressed in the block type.
+            if (!types_match(producer, consumer, a_it->second.type_id, b_it->second.type_id,
+                             producer_stage->arrayed_output && !a_it->second.is_patch && !a_it->second.is_block_member,
+                             consumer_stage->arrayed_input && !b_it->second.is_patch && !b_it->second.is_block_member, true)) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
+                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC", "Type mismatch on location %u.%u: '%s' vs '%s'",
+                                a_first.first, a_first.second, describe_type(producer, a_it->second.type_id).c_str(),
+                                describe_type(consumer, b_it->second.type_id).c_str());
+            }
+            if (a_it->second.is_patch != b_it->second.is_patch) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
+                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
+                                "Decoration mismatch on location %u.%u: is per-%s in %s stage but "
+                                    "per-%s in %s stage",
+                                a_first.first, a_first.second, a_it->second.is_patch ? "patch" : "vertex", producer_stage->name,
+                                b_it->second.is_patch ? "patch" : "vertex", consumer_stage->name);
+            }
+            if (a_it->second.is_relaxed_precision != b_it->second.is_relaxed_precision) {
+                skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, __LINE__,
+                                SHADER_CHECKER_INTERFACE_TYPE_MISMATCH, "SC",
+                                "Decoration mismatch on location %u.%u: %s and %s stages differ in precision", a_first.first,
+                                a_first.second, producer_stage->name, consumer_stage->name);
+            }
+            a_it++;
+            b_it++;
+        }
+    }
+
+    return skip;
+}
+
+// Validate that the shaders used by the given pipeline and store the active_slots
+//  that are actually used by the pipeline into pPipeline->active_slots
+bool validate_and_capture_pipeline_shader_state(layer_data *dev_data, PIPELINE_STATE *pPipeline) {
+    auto pCreateInfo = pPipeline->graphicsPipelineCI.ptr();
+    int vertex_stage = get_shader_stage_id(VK_SHADER_STAGE_VERTEX_BIT);
+    int fragment_stage = get_shader_stage_id(VK_SHADER_STAGE_FRAGMENT_BIT);
+    auto report_data = GetReportData(dev_data);
+
+    shader_module const *shaders[5];
+    memset(shaders, 0, sizeof(shaders));
+    spirv_inst_iter entrypoints[5];
+    memset(entrypoints, 0, sizeof(entrypoints));
+    bool skip = false;
+
+    for (uint32_t i = 0; i < pCreateInfo->stageCount; i++) {
+        auto pStage = &pCreateInfo->pStages[i];
+        auto stage_id = get_shader_stage_id(pStage->stage);
+        skip |= validate_pipeline_shader_stage(dev_data, pStage, pPipeline, &shaders[stage_id], &entrypoints[stage_id]);
+    }
+
+    // if the shader stages are no good individually, cross-stage validation is pointless.
+    if (skip) return true;
+
+    auto vi = pCreateInfo->pVertexInputState;
+
+    if (vi) {
+        skip |= validate_vi_consistency(report_data, vi);
+    }
+
+    if (shaders[vertex_stage] && shaders[vertex_stage]->has_valid_spirv) {
+        skip |= validate_vi_against_vs_inputs(report_data, vi, shaders[vertex_stage], entrypoints[vertex_stage]);
+    }
+
+    int producer = get_shader_stage_id(VK_SHADER_STAGE_VERTEX_BIT);
+    int consumer = get_shader_stage_id(VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT);
+
+    while (!shaders[producer] && producer != fragment_stage) {
+        producer++;
+        consumer++;
+    }
+
+    for (; producer != fragment_stage && consumer <= fragment_stage; consumer++) {
+        assert(shaders[producer]);
+        if (shaders[consumer] && shaders[consumer]->has_valid_spirv && shaders[producer]->has_valid_spirv) {
+            skip |= validate_interface_between_stages(report_data, shaders[producer], entrypoints[producer],
+                                                      &shader_stage_attribs[producer], shaders[consumer], entrypoints[consumer],
+                                                      &shader_stage_attribs[consumer]);
+
+            producer = consumer;
+        }
+    }
+
+    if (shaders[fragment_stage] && shaders[fragment_stage]->has_valid_spirv) {
+        skip |= validate_fs_outputs_against_render_pass(report_data, shaders[fragment_stage], entrypoints[fragment_stage],
+                                                        pPipeline->render_pass_ci.ptr(), pCreateInfo->subpass);
+    }
+
+    return skip;
+}
+
+bool validate_compute_pipeline(layer_data *dev_data, PIPELINE_STATE *pPipeline) {
+    auto pCreateInfo = pPipeline->computePipelineCI.ptr();
+
+    shader_module const *module;
+    spirv_inst_iter entrypoint;
+
+    return validate_pipeline_shader_stage(dev_data, &pCreateInfo->stage, pPipeline, &module, &entrypoint);
+}
diff --git a/layers/shader_validation.h b/layers/shader_validation.h
new file mode 100644
index 00000000..3d1c69eb
--- /dev/null
+++ b/layers/shader_validation.h
@@ -0,0 +1,107 @@
+/* Copyright (c) 2015-2017 The Khronos Group Inc.
+ * Copyright (c) 2015-2017 Valve Corporation
+ * Copyright (c) 2015-2017 LunarG, Inc.
+ * Copyright (C) 2015-2017 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Author: Chris Forbes <chrisf@ijw.co.nz>
+ */
+#ifndef VULKAN_SHADER_VALIDATION_H
+#define VULKAN_SHADER_VALIDATION_H
+
+// A forward iterator over spirv instructions. Provides easy access to len, opcode, and content words
+// without the caller needing to care too much about the physical SPIRV module layout.
+struct spirv_inst_iter {
+    std::vector<uint32_t>::const_iterator zero;
+    std::vector<uint32_t>::const_iterator it;
+
+    uint32_t len() {
+        auto result = *it >> 16;
+        assert(result > 0);
+        return result;
+    }
+
+    uint32_t opcode() { return *it & 0x0ffffu; }
+
+    uint32_t const &word(unsigned n) {
+        assert(n < len());
+        return it[n];
+    }
+
+    uint32_t offset() { return (uint32_t)(it - zero); }
+
+    spirv_inst_iter() {}
+
+    spirv_inst_iter(std::vector<uint32_t>::const_iterator zero, std::vector<uint32_t>::const_iterator it) : zero(zero), it(it) {}
+
+    bool operator==(spirv_inst_iter const &other) { return it == other.it; }
+
+    bool operator!=(spirv_inst_iter const &other) { return it != other.it; }
+
+    spirv_inst_iter operator++(int) {  // x++
+        spirv_inst_iter ii = *this;
+        it += len();
+        return ii;
+    }
+
+    spirv_inst_iter operator++() {  // ++x;
+        it += len();
+        return *this;
+    }
+
+    // The iterator and the value are the same thing.
+    spirv_inst_iter &operator*() { return *this; }
+    spirv_inst_iter const &operator*() const { return *this; }
+};
+
+struct shader_module {
+    // The spirv image itself
+    std::vector<uint32_t> words;
+    // A mapping of <id> to the first word of its def. this is useful because walking type
+    // trees, constant expressions, etc requires jumping all over the instruction stream.
+    std::unordered_map<unsigned, unsigned> def_index;
+    bool has_valid_spirv;
+
+    shader_module(VkShaderModuleCreateInfo const *pCreateInfo)
+        : words((uint32_t *)pCreateInfo->pCode, (uint32_t *)pCreateInfo->pCode + pCreateInfo->codeSize / sizeof(uint32_t)),
+          def_index(),
+          has_valid_spirv(true) {
+        build_def_index();
+    }
+
+    shader_module() : has_valid_spirv(false) {}
+
+    // Expose begin() / end() to enable range-based for
+    spirv_inst_iter begin() const { return spirv_inst_iter(words.begin(), words.begin() + 5); }  // First insn
+    spirv_inst_iter end() const { return spirv_inst_iter(words.begin(), words.end()); }          // Just past last insn
+    // Given an offset into the module, produce an iterator there.
+    spirv_inst_iter at(unsigned offset) const { return spirv_inst_iter(words.begin(), words.begin() + offset); }
+
+    // Gets an iterator to the definition of an id
+    spirv_inst_iter get_def(unsigned id) const {
+        auto it = def_index.find(id);
+        if (it == def_index.end()) {
+            return end();
+        }
+        return at(it->second);
+    }
+
+    void build_def_index();
+};
+
+bool validate_and_capture_pipeline_shader_state(layer_data *dev_data, PIPELINE_STATE *pPipeline);
+bool validate_compute_pipeline(layer_data *dev_data, PIPELINE_STATE *pPipeline);
+typedef std::pair<unsigned, unsigned> descriptor_slot_t;
+
+#endif //VULKAN_SHADER_VALIDATION_H