* cppmacro.c (_cpp_create_definition): Optimize the case of

        a macro defined to itself.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@37123 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 1 deletions

diff --git a/gcc/cppmacro.c b/gcc/cppmacro.c
index 58d3020797c..35e66f48054 100644
--- a/gcc/cppmacro.c
+++ b/gcc/cppmacro.c
@@ -1403,7 +1403,6 @@ _cpp_create_definition (pfile, node)
   macro->paramc = 0;
   macro->fun_like = 0;
   macro->var_args = 0;
-  macro->disabled = 0;
   macro->count = 0;
   macro->expansion = (cpp_token *) POOL_FRONT (&pfile->macro_pool);
 
@@ -1485,6 +1484,11 @@ _cpp_create_definition (pfile, node)
   /* Clear the whitespace flag from the leading token.  */
   macro->expansion[0].flags &= ~PREV_WHITE;
 
+  /* Implement the macro-defined-to-itself optimisation.  */
+  macro->disabled = (macro->count == 1 && !macro->fun_like
+		     && macro->expansion[0].type == CPP_NAME
+		     && macro->expansion[0].val.node == node);
+
   /* Commit the memory.  */
   POOL_COMMIT (&pfile->macro_pool, macro->count * sizeof (cpp_token));