From 016feb4b6bf4801e326e36702f66ad4f6a1c9d51 Mon Sep 17 00:00:00 2001
From: Mark Young <marky@lunarg.com>
Date: Thu, 9 Mar 2017 10:41:25 -0700
Subject: loader: Update secure_getenv check

The previous check was against the compiler, not against the libc.
Implement the check in CMake and generate a new header file which
defines appropriate defines (loader_cmake_config.h).

Change-Id: I2ae0e8d482fb4ce13089128157c11d18b0c178b9
---
 loader/CMakeLists.txt           |  6 ++++++
 loader/loader.c                 | 20 ++++++++++----------
 loader/loader_cmake_config.h.in |  2 ++
 3 files changed, 18 insertions(+), 10 deletions(-)
 create mode 100644 loader/loader_cmake_config.h.in

(limited to 'loader')

diff --git a/loader/CMakeLists.txt b/loader/CMakeLists.txt
index f7f898dc..118a7c76 100644
--- a/loader/CMakeLists.txt
+++ b/loader/CMakeLists.txt
@@ -5,6 +5,12 @@ include_directories(
     ${CMAKE_BINARY_DIR}
 )
 
+# Check for the existance of the secure_getenv or __secure_getenv commands
+include(CheckFunctionExists)
+CHECK_FUNCTION_EXISTS(secure_getenv HAVE_SECURE_GETENV)
+CHECK_FUNCTION_EXISTS(__secure_getenv HAVE___SECURE_GETENV)
+CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/loader_cmake_config.h.in ${CMAKE_CURRENT_BINARY_DIR}/loader_cmake_config.h)
+
 if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
     add_definitions(-DVK_USE_PLATFORM_WIN32_KHR -DWIN32_LEAN_AND_MEAN)
     set(DisplayServer Win32)
diff --git a/loader/loader.c b/loader/loader.c
index 65aa9392..bf450651 100644
--- a/loader/loader.c
+++ b/loader/loader.c
@@ -47,6 +47,11 @@
 #include "cJSON.h"
 #include "murmurhash.h"
 
+// This is a CMake generated file with #defines for any functions/includes
+// that it found present.  This is currently necessary to properly determine
+// if secure_getenv or __secure_getenv are present
+#include "loader_cmake_config.h"
+
 // Generated file containing all the extension data
 #include "vk_loader_extensions.c"
 
@@ -199,20 +204,15 @@ static inline char *loader_getenv(const char *name, const struct loader_instance
     // the inst pointer to get rid of compiler warnings.
     (void)inst;
 
-#if defined(__GNUC__)
-
-// Before GLIBC 2.17, the function was __secure_getenv not secure_getenv
-#if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 17))
-    return __secure_getenv(name);
-#else
+#ifdef HAVE_SECURE_GETENV
     return secure_getenv(name);
-#endif
-
-// Other compilers don't support secure_getenv
+#elif defined(HAVE___SECURE_GETENV)
+    return __secure_getenv(name);
 #else
+#pragma message("Warning:  Falling back to non-secure getenv for environmental lookups!  Consider" \
+                " updating to a different libc.")
     return getenv(name);
 #endif
-
 }
 
 static inline void loader_free_getenv(char *val, const struct loader_instance *inst) {
diff --git a/loader/loader_cmake_config.h.in b/loader/loader_cmake_config.h.in
new file mode 100644
index 00000000..3bbc4612
--- /dev/null
+++ b/loader/loader_cmake_config.h.in
@@ -0,0 +1,2 @@
+#cmakedefine HAVE_SECURE_GETENV
+#cmakedefine HAVE___SECURE_GETENV
-- 
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