1 files changed, 92 insertions, 18 deletions

diff --git a/src/glsl/glsl_parser.yy b/src/glsl/glsl_parser.yy
index b8f3df90e46..72bf560f07e 100644
--- a/src/glsl/glsl_parser.yy
+++ b/src/glsl/glsl_parser.yy
@@ -1314,34 +1314,108 @@ parameter_type_qualifier:
    ;
 
 type_qualifier:
-   storage_qualifier
-   | layout_qualifier
-   | layout_qualifier storage_qualifier
+   /* Single qualifiers */
+   INVARIANT
    {
-      $$ = $1;
-      $$.flags.i |= $2.flags.i;
+      memset(& $$, 0, sizeof($$));
+      $$.flags.q.invariant = 1;
    }
+   | storage_qualifier
    | interpolation_qualifier
-   | interpolation_qualifier storage_qualifier
-   {
-      $$ = $1;
-      $$.flags.i |= $2.flags.i;
-   }
-   | INVARIANT storage_qualifier
+   | layout_qualifier
+
+   /* Multiple qualifiers:
+    * In GLSL 4.20, these can be specified in any order.  In earlier versions,
+    * they appear in this order (see GLSL 1.50 section 4.7 & comments below):
+    *
+    *    invariant interpolation storage precision  ...or...
+    *    layout storage precision
+    *
+    * Each qualifier's rule ensures that the accumulated qualifiers on the right
+    * side don't contain any that must appear on the left hand side.
+    * For example, when processing a storage qualifier, we check that there are
+    * no interpolation, layout, or invariant qualifiers to the right.
+    */
+   | INVARIANT type_qualifier
    {
+      if ($2.flags.q.invariant)
+         _mesa_glsl_error(&@1, state, "Duplicate \"invariant\" qualifier.\n");
+
+      if ($2.has_layout()) {
+         _mesa_glsl_error(&@1, state,
+                          "\"invariant\" cannot be used with layout(...).\n");
+      }
+
       $$ = $2;
       $$.flags.q.invariant = 1;
    }
-   | INVARIANT interpolation_qualifier storage_qualifier
+   | interpolation_qualifier type_qualifier
+   {
+      /* Section 4.3 of the GLSL 1.40 specification states:
+       * "...qualified with one of these interpolation qualifiers"
+       *
+       * GLSL 1.30 claims to allow "one or more", but insists that:
+       * "These interpolation qualifiers may only precede the qualifiers in,
+       *  centroid in, out, or centroid out in a declaration."
+       *
+       * ...which means that e.g. smooth can't precede smooth, so there can be
+       * only one after all, and the 1.40 text is a clarification, not a change.
+       */
+      if ($2.has_interpolation())
+         _mesa_glsl_error(&@1, state, "Duplicate interpolation qualifier.\n");
+
+      if ($2.has_layout()) {
+         _mesa_glsl_error(&@1, state, "Interpolation qualifiers cannot be used "
+                          "with layout(...).\n");
+      }
+
+      if ($2.flags.q.invariant) {
+         _mesa_glsl_error(&@1, state, "Interpolation qualifiers must come "
+                          "after \"invariant\".\n");
+      }
+
+      $$ = $1;
+      $$.flags.i |= $2.flags.i;
+   }
+   | layout_qualifier type_qualifier
    {
-      $$ = $2;
-      $$.flags.i |= $3.flags.i;
-      $$.flags.q.invariant = 1;
+      /* The GLSL 1.50 grammar indicates that a layout(...) declaration can be
+       * used standalone or immediately before a storage qualifier.  It cannot
+       * be used with interpolation qualifiers or invariant.  There does not
+       * appear to be any text indicating that it must come before the storage
+       * qualifier, but always seems to in examples.
+       */
+      if ($2.has_layout())
+         _mesa_glsl_error(&@1, state, "Duplicate layout(...) qualifiers.\n");
+
+      if ($2.flags.q.invariant)
+         _mesa_glsl_error(&@1, state, "layout(...) cannot be used with "
+                          "the \"invariant\" qualifier\n");
+
+      if ($2.has_interpolation()) {
+         _mesa_glsl_error(&@1, state, "layout(...) cannot be used with "
+                          "interpolation qualifiers.\n");
+      }
+
+      $$ = $1;
+      $$.flags.i |= $2.flags.i;
    }
-   | INVARIANT
+   | storage_qualifier type_qualifier
    {
-      memset(& $$, 0, sizeof($$));
-      $$.flags.q.invariant = 1;
+      /* Section 4.3 of the GLSL 1.20 specification states:
+       * "Variable declarations may have a storage qualifier specified..."
+       *  1.30 clarifies this to "may have one storage qualifier".
+       */
+      if ($2.has_storage())
+         _mesa_glsl_error(&@1, state, "Duplicate storage qualifier.\n");
+
+      if ($2.flags.q.invariant || $2.has_interpolation() || $2.has_layout()) {
+         _mesa_glsl_error(&@1, state, "Storage qualifiers must come after "
+                          "invariant, interpolation, and layout qualifiers.\n");
+      }
+
+      $$ = $1;
+      $$.flags.i |= $2.flags.i;
    }
    ;