mesa: reference built-in uniforms into gl_uniform_storage

This change introduces a new field in gl_uniform_storage to
explicitely say that a uniform is built-in. In the case where it is,
no storage is defined to make it clear that it is read-only from the
mesa side. I fixed all the places in the code that made use of the
structure that I changed. Any place making a wrong assumption and using
the storage straight away will just crash.

This patch seems to implement the path of least resistance towards
listing built-in uniforms in GL_ACTIVE_UNIFORM (and other APIs).

Reviewed-by: Tapani Pälli <[email protected]>
Signed-off-by: Martin Peres <[email protected]>

4 files changed, 18 insertions, 7 deletions

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 737f0be6d62..0aa607653d1 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2728,7 +2728,7 @@ struct gl_shader_program
    } Comp;
 
    /* post-link info: */
-   unsigned NumUserUniformStorage;
+   unsigned NumUniformStorage;
    unsigned NumHiddenUniforms;
    struct gl_uniform_storage *UniformStorage;
 
diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index a04b28711f7..6d8e6e23e9c 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -569,13 +569,13 @@ get_programiv(struct gl_context *ctx, GLuint program, GLenum pname,
       *params = _mesa_longest_attribute_name_length(shProg);
       return;
    case GL_ACTIVE_UNIFORMS:
-      *params = shProg->NumUserUniformStorage - shProg->NumHiddenUniforms;
+      *params = shProg->NumUniformStorage - shProg->NumHiddenUniforms;
       return;
    case GL_ACTIVE_UNIFORM_MAX_LENGTH: {
       unsigned i;
       GLint max_len = 0;
       const unsigned num_uniforms =
-         shProg->NumUserUniformStorage - shProg->NumHiddenUniforms;
+         shProg->NumUniformStorage - shProg->NumHiddenUniforms;
 
       for (i = 0; i < num_uniforms; i++) {
 	 /* Add one for the terminating NUL character for a non-array, and
diff --git a/src/mesa/main/shaderobj.c b/src/mesa/main/shaderobj.c
index e428960362d..110a18e1e2c 100644
--- a/src/mesa/main/shaderobj.c
+++ b/src/mesa/main/shaderobj.c
@@ -282,10 +282,10 @@ _mesa_clear_shader_program_data(struct gl_shader_program *shProg)
    unsigned i;
 
    if (shProg->UniformStorage) {
-      for (i = 0; i < shProg->NumUserUniformStorage; ++i)
+      for (i = 0; i < shProg->NumUniformStorage; ++i)
          _mesa_uniform_detach_all_driver_storage(&shProg->UniformStorage[i]);
       ralloc_free(shProg->UniformStorage);
-      shProg->NumUserUniformStorage = 0;
+      shProg->NumUniformStorage = 0;
       shProg->UniformStorage = NULL;
    }
 
diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
index 728bd1bac10..cab5083e81b 100644
--- a/src/mesa/main/uniform_query.cpp
+++ b/src/mesa/main/uniform_query.cpp
@@ -237,6 +237,13 @@ validate_uniform_parameters(struct gl_context *ctx,
 
    struct gl_uniform_storage *const uni = shProg->UniformRemapTable[location];
 
+   /* Even though no location is assigned to a built-in uniform and this
+    * function should already have returned NULL, this test makes it explicit
+    * that we are not allowing to update the value of a built-in.
+    */
+   if (uni->builtin)
+      return NULL;
+
    if (uni->array_elements == 0) {
       if (count > 1) {
          _mesa_error(ctx, GL_INVALID_OPERATION,
@@ -1028,6 +1035,10 @@ _mesa_get_uniform_location(struct gl_shader_program *shProg,
    if (!found)
       return GL_INVALID_INDEX;
 
+   /* If the uniform is built-in, fail. */
+   if (shProg->UniformStorage[location].builtin)
+      return GL_INVALID_INDEX;
+
    /* If the uniform is an array, fail if the index is out of bounds.
     * (A negative index is caught above.)  This also fails if the uniform
     * is not an array, but the user is trying to index it, because
@@ -1047,7 +1058,7 @@ _mesa_sampler_uniforms_are_valid(const struct gl_shader_program *shProg,
 				 char *errMsg, size_t errMsgLength)
 {
    /* Shader does not have samplers. */
-   if (shProg->NumUserUniformStorage == 0)
+   if (shProg->NumUniformStorage == 0)
       return true;
 
    if (!shProg->SamplersValidated) {
@@ -1087,7 +1098,7 @@ _mesa_sampler_uniforms_pipeline_are_valid(struct gl_pipeline_object *pipeline)
       if (!shProg[idx])
          continue;
 
-      for (unsigned i = 0; i < shProg[idx]->NumUserUniformStorage; i++) {
+      for (unsigned i = 0; i < shProg[idx]->NumUniformStorage; i++) {
          const struct gl_uniform_storage *const storage =
             &shProg[idx]->UniformStorage[i];
          const glsl_type *const t = (storage->type->is_array())