glsl: Fix merging of layout(invocations) with other qualifiers

If another layout qualifier appeared to the left of `invocations` in the
GS input layout declaration, the invocation count would be dropped on
the floor.

Fixes the piglit tests:

spec/ARB_transform_feedback3/arb_transform_feedback3-ext_interleaved_two_bufs_gs_max
spec/ARB_gpu_shader5/arb_gpu_shader5-invocation-id
spec/ARB_gpu_shader5/compiler/correct-multiple-layout-qualifier-invocations.geom
spec/ARB_gpu_shader5/execution/invocations-conflicting

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Tested-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/glsl/ast_type.cpp b/src/glsl/ast_type.cpp
index de4c1a4..b596cd5 100644
--- a/src/glsl/ast_type.cpp
+++ b/src/glsl/ast_type.cpp
@@ -168,6 +168,16 @@ ast_type_qualifier::merge_qualifier(YYLTYPE *loc,
       this->max_vertices = q.max_vertices;
    }
 
+   if (q.flags.q.invocations) {
+      if (this->flags.q.invocations && this->invocations != q.invocations) {
+         _mesa_glsl_error(loc, state,
+                          "geometry shader set conflicting invocations "
+                          "(%d and %d)", this->invocations, q.invocations);
+         return false;
+      }
+      this->invocations = q.invocations;
+   }
+
    if (state->stage == MESA_SHADER_GEOMETRY &&
        state->has_explicit_attrib_stream()) {
       if (q.flags.q.stream && q.stream >= state->ctx->Const.MaxVertexStreams) {