glsl: Make it possible to disable a variable in the symbol table.

In later patches, we'll use this in order to implement the required
behaviour that after the gl_PerVertex interface block has been
redeclared, only members of the redeclared interface block may be
used.

v2: Update the function name and comment to clarify that we aren't
actually removing the variable from the symbol table, just disabling
it.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/glsl/glsl_symbol_table.h b/src/glsl/glsl_symbol_table.h
index 62d26b8..0e62448 100644
--- a/src/glsl/glsl_symbol_table.h
+++ b/src/glsl/glsl_symbol_table.h
@@ -121,6 +121,14 @@ public:
                                   enum ir_variable_mode mode);
    /*@}*/
 
+   /**
+    * Disable a previously-added variable so that it no longer appears to be
+    * in the symbol table.  This is necessary when gl_PerVertex is redeclared,
+    * to ensure that previously-available built-in variables are no longer
+    * available.
+    */
+   void disable_variable(const char *name);
+
 private:
    symbol_table_entry *get_entry(const char *name);