[Mesa-dev] [WIP 04/13] mesa: add a storage for inactive/removed uniform variables

[Tapani Pälli]

GL_ARB_explicit_uniform_location extension requires driver to reserve
locations for all uniforms (including inactive ones) when they have
explicit location set. Patch adds additional storage structure and a
list of locations reserved by inactive uniforms as part of the shader
program structure.

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
---
 src/mesa/main/mtypes.h    | 13 +++++++++++++
 src/mesa/main/shaderobj.c |  7 +++++++
 2 files changed, 20 insertions(+)

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index c8b8fa7..87d69c1 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2710,6 +2710,19 @@ struct gl_shader_program
    struct gl_uniform_storage **UniformRemapTable;
 
    /**
+    * This list contains explicit locations defined by inactive uniforms that
+    * were removed during the optimization pass (by opt_dead_code). This is
+    * used by linker to be able to still preserve locations for those
+    * uniforms.
+    *
+    * All removed uniforms have common storage 'RemovedUniformStorage' which
+    * is allocated once using ReservedUniformLocations as the ralloc context.
+    */
+   unsigned *ReservedUniformLocations;
+   unsigned NumReservedLocations;
+   struct gl_uniform_storage *RemovedUniformStorage;
+
+   /**
     * Size of the gl_ClipDistance array that is output from the last pipeline
     * stage before the fragment shader.
     */
diff --git a/src/mesa/main/shaderobj.c b/src/mesa/main/shaderobj.c
index b0f0bfa..7ec2827 100644
--- a/src/mesa/main/shaderobj.c
+++ b/src/mesa/main/shaderobj.c
@@ -287,6 +287,13 @@ _mesa_clear_shader_program_data(struct gl_context *ctx,
       shProg->UniformStorage = NULL;
    }
 
+   if (shProg->ReservedUniformLocations) {
+      ralloc_free(shProg->ReservedUniformLocations);
+      shProg->NumReservedLocations = 0;
+      shProg->ReservedUniformLocations = NULL;
+      shProg->RemovedUniformStorage = NULL;
+   }
+
    if (shProg->UniformRemapTable) {
       ralloc_free(shProg->UniformRemapTable);
       shProg->NumUniformRemapTable = 0;
-- 
1.8.3.1