[Mesa-dev] [PATCH 1/2] glsl: add a mechanism to allow #extension directives in the middle of shaders

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

This is needed to make Unigine Heaven 4.0 and Unigine Valley 1.0 work
with sample shading.

Also, if this is disabled, the error message at least makes sense now.
---
 src/glsl/glsl_parser.yy         | 8 ++++++++
 src/glsl/glsl_parser_extras.cpp | 2 ++
 src/glsl/glsl_parser_extras.h   | 2 ++
 src/mesa/main/mtypes.h          | 5 +++++
 4 files changed, 17 insertions(+)

diff --git a/src/glsl/glsl_parser.yy b/src/glsl/glsl_parser.yy
index b989749..4c87163 100644
--- a/src/glsl/glsl_parser.yy
+++ b/src/glsl/glsl_parser.yy
@@ -376,6 +376,14 @@ external_declaration_list:
       if ($2 != NULL)
          state->translation_unit.push_tail(& $2->link);
    }
+   | external_declaration_list extension_statement {
+      if (!state->allow_extension_directive_midshader) {
+         _mesa_glsl_error(& @2, state,
+                          "#extension directive is not allowed "
+                          "in the middle of a shader");
+         YYERROR;
+      }
+   }
    ;
 
 variable_identifier:
diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index b327c2b..890123a 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -210,6 +210,8 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
    this->early_fragment_tests = false;
    memset(this->atomic_counter_offsets, 0,
           sizeof(this->atomic_counter_offsets));
+   this->allow_extension_directive_midshader =
+      ctx->Const.AllowGLSLExtensionDirectiveMidShader;
 }
 
 /**
diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
index 1791816..f720d6a 100644
--- a/src/glsl/glsl_parser_extras.h
+++ b/src/glsl/glsl_parser_extras.h
@@ -490,6 +490,8 @@ struct _mesa_glsl_parse_state {
 
    /** Atomic counter offsets by binding */
    unsigned atomic_counter_offsets[MAX_COMBINED_ATOMIC_BUFFERS];
+
+   bool allow_extension_directive_midshader;
 };
 
 # define YYLLOC_DEFAULT(Current, Rhs, N)			\
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index a7126fd..b42a175 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3349,6 +3349,11 @@ struct gl_constants
    GLuint ForceGLSLVersion;
 
    /**
+    * Allow GLSL #extension directives in the middle of shaders.
+    */
+   GLboolean AllowGLSLExtensionDirectiveMidShader;
+
+   /**
     * Does the driver support real 32-bit integers?  (Otherwise, integers are
     * simulated via floats.)
     */
-- 
1.9.1