[Mesa-dev] [PATCH 3/3] glsl: Interface Block instances don't need linking validation

[Andres Gomez]

>From page 45 (page 52 of the PDF) of the GLSL ES 3.00 v.6 spec:

  " When instance names are present on matched block names, it is
    allowed for the instance names to differ; they need not match for
    the blocks to match.

>From page 51 (page 57 of the PDF) of the GLSL 4.30 v.8 spec:

  " When instance names are present on matched block names, it is
    allowed for the instance names to differ; they need not match for
    the blocks to match."

Therefore, no cross linking validation is needed for the instance name
of an Interface Block.

This patch will make that no link error will be reported on a program
like this:

    "# VS

    layout(binding = 1) Block1 {
      vec4 color;
    } uni_block;

    ...

    # FS

    layout(binding = 2) Block2 {
      vec4 color;
    } uni_block;

    ..."

Fixes GL45-CTS.enhanced_layouts.ssb_layout_qualifier_conflict

Signed-off-by: Andres Gomez <agomez at igalia.com>
Cc: Timothy Arceri <tarceri at itsqueeze.com>
---
 src/compiler/glsl/linker.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index bb9c101f430..7abdeeb5fb1 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -885,6 +885,13 @@ cross_validate_globals(struct gl_shader_program *prog,
       if (var->type->contains_subroutine())
          continue;
 
+      /* Don't cross validate interface instances. These are only relevant
+       * inside a shader. The cross validation is done at the Interface Block
+       * name level.
+       */
+      if (var->is_interface_instance())
+         continue;
+
       /* Don't cross validate temporaries that are at global scope.  These
        * will eventually get pulled into the shaders 'main'.
        */
@@ -897,11 +904,8 @@ cross_validate_globals(struct gl_shader_program *prog,
        */
       ir_variable *const existing = variables->get_variable(var->name);
       if (existing != NULL) {
-         /* Check if types match. Interface blocks have some special
-          * rules so we handle those elsewhere.
-          */
-         if (var->type != existing->type &&
-             !var->is_interface_instance()) {
+         /* Check if types match. */
+         if (var->type != existing->type) {
             if (!validate_intrastage_arrays(prog, var, existing)) {
                if (var->type->is_record() && existing->type->is_record()
                    && existing->type->record_compare(var->type)) {
-- 
2.11.0