glsl: Fix gl_shader_stage enum unsigned comparison

Replace -1 with MESA_SHADER_NONE enum value to fix sign related warning:

external/mesa3d/src/compiler/glsl/link_varyings.cpp:1415:25: warning: comparison of constant -1 with expression of type 'gl_shader_stage' is always true [-Wtautological-constant-out-of-range-compare]
        (consumer_stage != -1 && consumer_stage != MESA_SHADER_FRAGMENT))) {
         ~~~~~~~~~~~~~~ ^  ~~

Reviewed-by: Nicolai Hähnle <[email protected]>
Signed-off-by: Rob Herring <[email protected]>

4 files changed, 14 insertions, 4 deletions

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index e451bda8016..e07e5f509b5 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -3245,6 +3245,9 @@ apply_explicit_location(const struct ast_type_qualifier *qual,
                        "compute shader variables cannot be given "
                        "explicit locations");
       return;
+   default:
+      fail = true;
+      break;
    };
 
    if (fail) {
@@ -3276,7 +3279,7 @@ apply_explicit_location(const struct ast_type_qualifier *qual,
             ? (qual_location + FRAG_RESULT_DATA0)
             : (qual_location + VARYING_SLOT_VAR0);
          break;
-      case MESA_SHADER_COMPUTE:
+      default:
          assert(!"Unexpected shader type");
          break;
       }
@@ -4089,6 +4092,8 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
       case MESA_SHADER_COMPUTE:
          /* Invariance isn't meaningful in compute shaders. */
          break;
+      default:
+         break;
       }
    }
 
diff --git a/src/compiler/glsl/builtin_variables.cpp b/src/compiler/glsl/builtin_variables.cpp
index ce4dd43730c..405502eb8a4 100644
--- a/src/compiler/glsl/builtin_variables.cpp
+++ b/src/compiler/glsl/builtin_variables.cpp
@@ -1324,6 +1324,8 @@ builtin_variable_generator::add_varying(int slot, const glsl_type *type,
    case MESA_SHADER_COMPUTE:
       /* Compute shaders don't have varyings. */
       break;
+   default:
+      break;
    }
 }
 
@@ -1461,6 +1463,8 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
    case MESA_SHADER_COMPUTE:
       gen.generate_cs_special_vars();
       break;
+   default:
+      break;
    }
 }
 
diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp
index d04f546c243..910e2eda82b 100644
--- a/src/compiler/glsl/link_varyings.cpp
+++ b/src/compiler/glsl/link_varyings.cpp
@@ -1412,7 +1412,7 @@ varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
 
    if (!disable_varying_packing &&
        (needs_flat_qualifier ||
-        (consumer_stage != -1 && consumer_stage != MESA_SHADER_FRAGMENT))) {
+        (consumer_stage != MESA_SHADER_NONE && consumer_stage != MESA_SHADER_FRAGMENT))) {
       /* Since this varying is not being consumed by the fragment shader, its
        * interpolation type varying cannot possibly affect rendering.
        * Also, this variable is non-flat and is (or contains) an integer
@@ -2170,8 +2170,8 @@ assign_varying_locations(struct gl_context *ctx,
 
    varying_matches matches(disable_varying_packing, xfb_enabled,
                            ctx->Extensions.ARB_enhanced_layouts,
-                           producer ? producer->Stage : (gl_shader_stage)-1,
-                           consumer ? consumer->Stage : (gl_shader_stage)-1);
+                           producer ? producer->Stage : MESA_SHADER_NONE,
+                           consumer ? consumer->Stage : MESA_SHADER_NONE);
    hash_table *tfeedback_candidates =
          _mesa_hash_table_create(NULL, _mesa_key_hash_string,
                                  _mesa_key_string_equal);
diff --git a/src/compiler/shader_enums.h b/src/compiler/shader_enums.h
index 07db4767f86..352f27040ce 100644
--- a/src/compiler/shader_enums.h
+++ b/src/compiler/shader_enums.h
@@ -39,6 +39,7 @@ extern "C" {
  */
 typedef enum
 {
+   MESA_SHADER_NONE = -1,
    MESA_SHADER_VERTEX = 0,
    MESA_SHADER_TESS_CTRL = 1,
    MESA_SHADER_TESS_EVAL = 2,