Mesa (master): glsl: add a mechanism to allow #extension directives in the middle of shaders

[Marek Olšák]

Module: Mesa
Branch: master
Commit: b0ff18bd3441ce7f28354686934440a92826eaf8
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b0ff18bd3441ce7f28354686934440a92826eaf8

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Tue Jul  8 20:20:22 2014 +0200

glsl: add a mechanism to allow #extension directives in the middle of shaders

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.

Reviewed-by: Brian Paul <brianp at vmware.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 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 6df41d4..ce66e2f 100644
--- a/src/glsl/glsl_parser_extras.h
+++ b/src/glsl/glsl_parser_extras.h
@@ -493,6 +493,8 @@ 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 b699021..91d9172 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3363,6 +3363,11 @@ 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.)
     */