glsl: Linker support for ARB_shader_atomic_counters.

v2: Add comments on the purpose of the auxiliary data structures.
    Check for atomic counter overlaps.  Use the contains_atomic()
    convenience method.  Add static assert with the number of expected
    shader stages.
v3: Don't resize atomic arrays.
v4: Add comment on the reason why we don't resize atomic counter
    arrays.  Use 'strcmp(...) == 0' instead of '!strcmp(...)'.
v5 (idr):  Don't use STL in the linker.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 49bb142..1d53b65 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -651,6 +651,14 @@ cross_validate_globals(struct gl_shader_program *prog,
                existing->explicit_binding = true;
             }
 
+            if (var->type->contains_atomic() &&
+                var->atomic.offset != existing->atomic.offset) {
+               linker_error(prog, "offset specifications for %s "
+                            "`%s' have differing values\n",
+                            mode_string(var), var->name);
+               return;
+            }
+
 	    /* Validate layout qualifiers for gl_FragDepth.
 	     *
 	     * From the AMD/ARB_conservative_depth specs:
@@ -1485,8 +1493,12 @@ update_array_sizes(struct gl_shader_program *prog)
 	 /* GL_ARB_uniform_buffer_object says that std140 uniforms
 	  * will not be eliminated.  Since we always do std140, just
 	  * don't resize arrays in UBOs.
+          *
+          * Atomic counters are supposed to get deterministic
+          * locations assigned based on the declaration ordering and
+          * sizes, array compaction would mess that up.
 	  */
-	 if (var->is_in_uniform_block())
+	 if (var->is_in_uniform_block() || var->type->contains_atomic())
 	    continue;
 
 	 unsigned int size = var->max_array_access;
@@ -1991,6 +2003,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       prog->UniformBlockStageIndex[i] = NULL;
    }
 
+   ralloc_free(prog->AtomicBuffers);
+   prog->AtomicBuffers = NULL;
+   prog->NumAtomicBuffers = 0;
+
    /* Separate the shaders into groups based on their type.
     */
    struct gl_shader **vert_shader_list;
@@ -2342,9 +2358,12 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
    update_array_sizes(prog);
    link_assign_uniform_locations(prog);
+   link_assign_atomic_counter_resources(ctx, prog);
    store_fragdepth_layout(prog);
 
    check_resources(ctx, prog);
+   link_check_atomic_counter_resources(ctx, prog);
+
    if (!prog->LinkStatus)
       goto done;