[Mesa-dev] [PATCH 06/21] glsl: validate and store component layout qualifier in GLSL IR

[Timothy Arceri]

We make use of the existing IR field location_frac used for tracking
component locations.
---
 src/glsl/ast_to_hir.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 src/glsl/ir.h           |  5 +++++
 2 files changed, 43 insertions(+)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 1091c02..bb35d72 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -3075,10 +3075,42 @@ apply_layout_qualifier_to_variable(const struct ast_type_qualifier *qual,
 
    if (qual->flags.q.explicit_location) {
       apply_explicit_location(qual, var, state, loc);
+
+      if (qual->flags.q.explicit_component) {
+         unsigned qual_component;
+         if (process_qualifier_constant(state, loc, "component",
+                                        qual->component, &qual_component)) {
+            const glsl_type *type = var->type->without_array();
+            unsigned components = type->component_slots();
+
+            if (type->is_matrix() || type->is_record()) {
+               _mesa_glsl_error(loc, state, "component layout qualifier "
+                                "cannot be applied to a matrix, a structure, "
+                                "a block, or an array containing any of "
+                                "these.");
+            } else if (qual_component != 0 &&
+                (qual_component + components - 1) > 3) {
+               _mesa_glsl_error(loc, state, "component overflow (%u > 3)",
+                                (qual_component + components - 1));
+            } else if (qual_component == 1 && type->is_double()) {
+               /* We don't bother checking for 3 as it should be caught by the
+                * overflow check above.
+                */
+               _mesa_glsl_error(loc, state, "doubles cannot begin at "
+                                "component 1 or 3");
+            } else {
+               var->data.explicit_component = true;
+               var->data.location_frac = qual_component;
+            }
+         }
+      }
    } else if (qual->flags.q.explicit_index) {
       if (!qual->flags.q.subroutine_def)
          _mesa_glsl_error(loc, state,
                           "explicit index requires explicit location");
+   } else if (qual->flags.q.explicit_component) {
+      _mesa_glsl_error(loc, state,
+                       "explicit component requires explicit location");
    }
 
    if (qual->flags.q.explicit_binding) {
@@ -6660,6 +6692,12 @@ ast_interface_block::hir(exec_list *instructions,
                        "Interface block sets both readonly and writeonly");
    }
 
+   if (this->layout.flags.q.explicit_component) {
+      _mesa_glsl_error(&loc, state, "component layout qualifier cannot be "
+                       "applied to a matrix, a structure, a block, or an "
+                       "array containing any of these.");
+   }
+
    unsigned qual_stream;
    if (!process_qualifier_constant(state, &loc, "stream", this->layout.stream,
                                    &qual_stream) ||
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 159f94d..d604a1f 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -714,6 +714,11 @@ public:
       unsigned explicit_binding:1;
 
       /**
+       * Was an initial component explicitly set in the shader?
+       */
+      unsigned explicit_component:1;
+
+      /**
        * Does this variable have an initializer?
        *
        * This is used by the linker to cross-validiate initializers of global
-- 
2.4.3