glsl: a shader storage buffer must be smaller than the maximum size allowed

Otherwise, generate a link time error as per the
ARB_shader_storage_buffer_object spec.

v2:
- Fix error message (Jordan)

v3:
- Move std140_size() changes to its own patch (Kristian)

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>

src/glsl/link_uniform_blocks.cpp

@@ -187,6 +187,7 @@ struct block {
 
 unsigned
 link_uniform_blocks(void *mem_ctx,
+                    struct gl_context *ctx,
                     struct gl_shader_program *prog,
                     struct gl_shader **shader_list,
                     unsigned num_shaders,
@@ -308,6 +309,15 @@ link_uniform_blocks(void *mem_ctx,
 
             blocks[i].UniformBufferSize = parcel.buffer_size;
 
+            /* Check SSBO size is lower than maximum supported size for SSBO */
+            if (b->is_shader_storage &&
+                parcel.buffer_size > ctx->Const.MaxShaderStorageBlockSize) {
+               linker_error(prog, "shader storage block `%s' has size %d, "
+                            "which is larger than than the maximum allowed (%d)",
+                            block_type->name,
+                            parcel.buffer_size,
+                            ctx->Const.MaxShaderStorageBlockSize);
+            }
             blocks[i].NumUniforms =
                (unsigned)(ptrdiff_t)(&variables[parcel.index] - blocks[i].Uniforms);
 
@@ -328,6 +338,15 @@ link_uniform_blocks(void *mem_ctx,
 
          blocks[i].UniformBufferSize = parcel.buffer_size;
 
+         /* Check SSBO size is lower than maximum supported size for SSBO */
+         if (b->is_shader_storage &&
+             parcel.buffer_size > ctx->Const.MaxShaderStorageBlockSize) {
+            linker_error(prog, "shader storage block `%s' has size %d, "
+                         "which is larger than than the maximum allowed (%d)",
+                         block_type->name,
+                         parcel.buffer_size,
+                         ctx->Const.MaxShaderStorageBlockSize);
+         }
          blocks[i].NumUniforms =
             (unsigned)(ptrdiff_t)(&variables[parcel.index] - blocks[i].Uniforms);
 

src/glsl/linker.cpp

@@ -1996,7 +1996,7 @@ link_intrastage_shaders(void *mem_ctx,
 
    /* Link up uniform blocks defined within this stage. */
    const unsigned num_uniform_blocks =
-      link_uniform_blocks(mem_ctx, prog, shader_list, num_shaders,
+      link_uniform_blocks(mem_ctx, ctx, prog, shader_list, num_shaders,
                           &uniform_blocks);
    if (!prog->LinkStatus)
       return NULL;

src/glsl/linker.h

@@ -53,6 +53,7 @@ link_uniform_blocks_are_compatible(const gl_uniform_block *a,
 
 extern unsigned
 link_uniform_blocks(void *mem_ctx,
+                    struct gl_context *ctx,
                     struct gl_shader_program *prog,
                     struct gl_shader **shader_list,
                     unsigned num_shaders,