[Mesa-dev] [PATCH] glsl: non-last member unsized array on SSBO must fail compilation on GLSL ES 3.1

[Jose Maria Casanova Crespo]

>From GLSL ES 3.10 spec, section 4.1.9 "Arrays":

"If an array is declared as the last member of a shader storage block
 and the size is not specified at compile-time, it is sized at run-time.
 In all other cases, arrays are sized only at compile-time."

In desktop GLSL it is allowed to have unsized-arrays that are
not last, as long as we can determine that they are implicitly
sized, which is detected at link-time.

With this patch Mesa reports a compilation error as glslang does with
the following shader:

buffer SSBO { vec4 data[]; vec4 moreData;};
void main (void)
{
}

Fixes:
dEQP-GLES31.functional.debug.negative_coverage.log.shader.compile_compute_shader
dEQP-GLES31.functional.debug.negative_coverage.callbacks.shader.compile_compute_shader
dEQP-GLES31.functional.debug.negative_coverage.get_error.shader.compile_compute_shader

Cc: "17.0" <mesa-stable at lists.freedesktop.org>
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova at igalia.com>
---
 src/compiler/glsl/ast_to_hir.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index b31b61d..ee47b65 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -7903,10 +7903,9 @@ ast_interface_block::hir(exec_list *instructions,
          }
 
          if (var->type->is_unsized_array()) {
-            if (var->is_in_shader_storage_block()) {
-               if (is_unsized_array_last_element(var)) {
-                  var->data.from_ssbo_unsized_array = true;
-               }
+            if (var->is_in_shader_storage_block() &&
+                is_unsized_array_last_element(var)) {
+               var->data.from_ssbo_unsized_array = true;
             } else {
                /* From GLSL ES 3.10 spec, section 4.1.9 "Arrays":
                 *
@@ -7914,6 +7913,10 @@ ast_interface_block::hir(exec_list *instructions,
                 * block and the size is not specified at compile-time, it is
                 * sized at run-time. In all other cases, arrays are sized only
                 * at compile-time."
+                *
+                * In desktop GLSL it is allowed to have unsized-arrays that are
+                * not last, as long as we can determine that they are implicitly
+                * sized.
                 */
                if (state->es_shader) {
                   _mesa_glsl_error(&loc, state, "unsized array `%s' "
-- 
2.9.3