mesa: Add a flag for shader programs to allow SSO linkage in GLES2.

On converting fixed function programs to generate GLSL, the linker
became cranky that we were trying to make something that wasn't a
linked vertex+fragment program.  Given that the Mesa GLES2 drivers
also support desktop GL with EXT_sso, just telling the linker to shut
up seems like the easiest solution.

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 42075cbbe09410a40d07220544ac20b1e18e4f59..a7c38a3426a5f914d638476d698112aa9cc113ad 100644 (file)
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1805,7 +1805,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
     * present in a linked program.  By checking for use of shading language
     * version 1.00, we also catch the GL_ARB_ES2_compatibility case.
     */
-   if (ctx->API == API_OPENGLES2 || prog->Version == 100) {
+   if (!prog->InternalSeparateShader &&
+       (ctx->API == API_OPENGLES2 || prog->Version == 100)) {
       if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) {
         linker_error(prog, "program lacks a vertex shader\n");
       } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index a7d1cb2b11141dca952a5e02b660726ac069d215..17c645a7ee5e25eeadfb0c4b5953cb9c53b85e43 100644 (file)
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2135,6 +2135,17 @@ struct gl_shader_program
    GLint RefCount;  /**< Reference count */
    GLboolean DeletePending;
 
+   /**
+    * Flags that the linker should not reject the program if it lacks
+    * a vertex or fragment shader.  GLES2 doesn't allow separate
+    * shader objects, and would reject them.  However, we internally
+    * build separate shader objects for fixed function programs, which
+    * we use for drivers/common/meta.c and for handling
+    * _mesa_update_state with no program bound (for example in
+    * glClear()).
+    */
+   GLboolean InternalSeparateShader;
+
    GLuint NumShaders;          /**< number of attached shaders */
    struct gl_shader **Shaders; /**< List of attached the shaders */