glsl: move stream layout qualifier validation

We are moving this out of the parser in preparation for compile
time constant support.

The reason a validation function is used rather than an apply
function like what is used with bindings is because glsl allows
streams to be defined on members of blocks even though they must
match the stream thats associated with the current block, this
means we need access to the value after validation to do this
comparision.

V2: Fix typo in comment (Emil)

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/glsl/ast_to_hir.cpp

@@ -3034,7 +3034,11 @@ apply_layout_qualifier_to_variable(const struct ast_type_qualifier *qual,
 
    if (state->stage == MESA_SHADER_GEOMETRY &&
        qual->flags.q.out && qual->flags.q.stream) {
-      var->data.stream = qual->stream;
+      unsigned qual_stream;
+      if (process_qualifier_constant(state, loc, "stream", qual->stream,
+                                     &qual_stream)) {
+         var->data.stream = qual_stream;
+      }
    }
 
    if (var->type->contains_atomic()) {
@@ -6080,7 +6084,8 @@ ast_process_struct_or_iface_block_members(exec_list *instructions,
                                           enum glsl_matrix_layout matrix_layout,
                                           bool allow_reserved_names,
                                           ir_variable_mode var_mode,
-                                          ast_type_qualifier *layout)
+                                          ast_type_qualifier *layout,
+                                          unsigned block_stream)
 {
    unsigned decl_count = 0;
 
@@ -6188,11 +6193,16 @@ ast_process_struct_or_iface_block_members(exec_list *instructions,
        *   the specified stream must match the stream associated with the
        *   containing block."
        */
-      if (qual->flags.q.explicit_stream &&
+      if (qual->flags.q.explicit_stream) {
-          qual->stream != layout->stream) {
+         unsigned qual_stream;
-         _mesa_glsl_error(&loc, state, "stream layout qualifier on interface "
+         if (process_qualifier_constant(state, &loc, "stream",
-                          "block member does not match the interface block "
+                                        qual->stream, &qual_stream) &&
-                          "(%d vs %d)", qual->stream, layout->stream);
+             qual_stream != block_stream) {
+            _mesa_glsl_error(&loc, state, "stream layout qualifier on "
+                             "interface block member does not match "
+                             "the interface block (%d vs %d)", qual->stream,
+                             block_stream);
+         }
       }
 
       if (qual->flags.q.uniform && qual->has_interpolation()) {
@@ -6350,7 +6360,8 @@ ast_struct_specifier::hir(exec_list *instructions,
                                                 GLSL_MATRIX_LAYOUT_INHERITED,
                                                 false /* allow_reserved_names */,
                                                 ir_var_auto,
-                                                NULL);
+                                                NULL,
+                                                0 /* for interface only */);
 
    validate_identifier(this->name, loc, state);
 
@@ -6504,6 +6515,16 @@ ast_interface_block::hir(exec_list *instructions,
                        "Interface block sets both readonly and writeonly");
    }
 
+   unsigned qual_stream;
+   if (!process_qualifier_constant(state, &loc, "stream", this->layout.stream,
+                                   &qual_stream)) {
+      /* If the stream qualifier is invalid it doesn't make sense to continue
+       * on and try to compare stream layouts on member variables against it
+       * so just return early.
+       */
+      return NULL;
+   }
+
    unsigned int num_variables =
       ast_process_struct_or_iface_block_members(&declared_variables,
                                                 state,
@@ -6513,7 +6534,8 @@ ast_interface_block::hir(exec_list *instructions,
                                                 matrix_layout,
                                                 redeclaring_per_vertex,
                                                 var_mode,
-                                                &this->layout);
+                                                &this->layout,
+                                                qual_stream);
 
    state->struct_specifier_depth--;
 
@@ -6859,7 +6881,7 @@ ast_interface_block::hir(exec_list *instructions,
          var->data.explicit_binding = this->layout.flags.q.explicit_binding;
          var->data.binding = this->layout.binding;
 
-         var->data.stream = this->layout.stream;
+         var->data.stream = qual_stream;
 
          state->symbols->add_variable(var);
          instructions->push_tail(var);
@@ -6879,7 +6901,7 @@ ast_interface_block::hir(exec_list *instructions,
          var->data.centroid = fields[i].centroid;
          var->data.sample = fields[i].sample;
          var->data.patch = fields[i].patch;
-         var->data.stream = this->layout.stream;
+         var->data.stream = qual_stream;
          var->init_interface_type(block_type);
 
          if (var_mode == ir_var_shader_in || var_mode == ir_var_uniform)

src/glsl/glsl_parser.yy

@@ -1514,15 +1514,8 @@ layout_qualifier_id:
          if (match_layout_qualifier("stream", $1, state) == 0 &&
              state->check_explicit_attrib_stream_allowed(& @3)) {
             $$.flags.q.stream = 1;
-
+            $$.flags.q.explicit_stream = 1;
-            if ($3 < 0) {
+            $$.stream = $3;
-               _mesa_glsl_error(& @3, state,
-                                "invalid stream %d specified", $3);
-               YYERROR;
-            } else {
-               $$.flags.q.explicit_stream = 1;
-               $$.stream = $3;
-            }
          }
       }