Initial pass on API stability guarantees

This introduces -DWLR_USE_UNSTABLE and adds information regarding the
stability status to all headers. I started with a conservative set of
headers to mark as stable:

- types/wlr_matrix.h
- util/edges.h
- util/log.h
- util/region.h
- xcursor.h

6 files changed, 48 insertions, 0 deletions

diff --git a/include/wlr/render/dmabuf.h b/include/wlr/render/dmabuf.h
index 78f8c2eb..33c3a129 100644
--- a/include/wlr/render/dmabuf.h
+++ b/include/wlr/render/dmabuf.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_DMABUF_H
 #define WLR_RENDER_DMABUF_H
 
diff --git a/include/wlr/render/egl.h b/include/wlr/render/egl.h
index 6b887f4f..c42b0325 100644
--- a/include/wlr/render/egl.h
+++ b/include/wlr/render/egl.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_EGL_H
 #define WLR_RENDER_EGL_H
 
diff --git a/include/wlr/render/gles2.h b/include/wlr/render/gles2.h
index 866c6658..fca11ab8 100644
--- a/include/wlr/render/gles2.h
+++ b/include/wlr/render/gles2.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_GLES2_H
 #define WLR_RENDER_GLES2_H
 
diff --git a/include/wlr/render/interface.h b/include/wlr/render/interface.h
index f4565ad5..63f4265c 100644
--- a/include/wlr/render/interface.h
+++ b/include/wlr/render/interface.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_INTERFACE_H
 #define WLR_RENDER_INTERFACE_H
 
diff --git a/include/wlr/render/wlr_renderer.h b/include/wlr/render/wlr_renderer.h
index 0650bf1b..9c031b7f 100644
--- a/include/wlr/render/wlr_renderer.h
+++ b/include/wlr/render/wlr_renderer.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_WLR_RENDERER_H
 #define WLR_RENDER_WLR_RENDERER_H
 
diff --git a/include/wlr/render/wlr_texture.h b/include/wlr/render/wlr_texture.h
index 9370fa25..dbfabfee 100644
--- a/include/wlr/render/wlr_texture.h
+++ b/include/wlr/render/wlr_texture.h
@@ -1,3 +1,11 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
 #ifndef WLR_RENDER_WLR_TEXTURE_H
 #define WLR_RENDER_WLR_TEXTURE_H