[Mesa-dev] [PATCH 14/19] glsl: Make it possible to remove a variable from the symbol table.

[Paul Berry]

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.
---
 src/glsl/glsl_symbol_table.cpp | 9 +++++++++
 src/glsl/glsl_symbol_table.h   | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/src/glsl/glsl_symbol_table.cpp b/src/glsl/glsl_symbol_table.cpp
index 6e916b4..694713a 100644
--- a/src/glsl/glsl_symbol_table.cpp
+++ b/src/glsl/glsl_symbol_table.cpp
@@ -256,3 +256,12 @@ symbol_table_entry *glsl_symbol_table::get_entry(const char *name)
    return (symbol_table_entry *)
       _mesa_symbol_table_find_symbol(table, -1, name);
 }
+
+void
+glsl_symbol_table::remove_variable(const char *name)
+{
+   symbol_table_entry *entry = get_entry(name);
+   if (entry != NULL) {
+      entry->v = NULL;
+   }
+}
diff --git a/src/glsl/glsl_symbol_table.h b/src/glsl/glsl_symbol_table.h
index 62d26b8..b73db3b 100644
--- a/src/glsl/glsl_symbol_table.h
+++ b/src/glsl/glsl_symbol_table.h
@@ -121,6 +121,13 @@ public:
                                   enum ir_variable_mode mode);
    /*@}*/
 
+   /**
+    * Remove a variable from the symbol table.  This is necessary when
+    * gl_PerVertex is redeclared, to ensure that previously-available built-in
+    * variables are no longer available.
+    */
+   void remove_variable(const char *name);
+
 private:
    symbol_table_entry *get_entry(const char *name);
 
-- 
1.8.4