From 5950c3c9a7729687a04f9b008e441959a2d9114d Mon Sep 17 00:00:00 2001
From: Ben Elliston <bje@au.ibm.com>
Date: Mon, 14 Jul 2008 05:09:48 +0000
Subject: cpplib.h (NODE_CONDITIONAL): New.

libcpp/
	* include/cpplib.h (NODE_CONDITIONAL): New.
	(struct cpp_callbacks): New macro_to_expand field.
	(struct cpp_hashnode): Adjust size of flags and type fields.
	(cpp_peek_token): Prototype.
	* lex.c (cpp_peek_token): New function.
	(_cpp_temp_token): Protect pre-existing lookaheads.
	* macro.c (cpp_get_token): Expand any conditional macros.
	(_cpp_backup_tokens_direct): New.
	(_cpp_backup_tokens): Call _cpp_backup_tokens_direct.
	(warn_of_redefinition): Silently allow redefined conditional
	macros.
	(_cpp_create_definition): Remove the conditional flag when a user
	defines one of the conditional macros.
	* internal.h (_cpp_backup_tokens_direct): New prototype.

gcc/
	* c-common.h (C_CPP_HASHNODE): New macro.
	* coretypes.h (struct cpp_token): Forward declare.
	* doc/extend.texi (PowerPC AltiVec Built-in Functions): Document
	the context-sensitive keyword method.
	* config/rs6000/rs6000-c.c (__vector_keyword, vector_keyword,
	__pixel_keyword, pixel_keyword, __bool_keyword, bool_keyword,
	expand_bool_pixel): New.
	(altivec_categorize_keyword): New function.
	(init_vector_keywords): New function.
	(rs6000_macro_to_expand): Likewise.
	(rs6000_cpu_cpp_builtins): Enable context-sensitive macros if not
	compiling an ISO C dialect.

gcc/testsuite/
	* gcc.target/powerpc/altivec-macros.c: New test.
	* gcc.target/powerpc/altviec-26.c: Likewise.
	* gcc.dg/vmx/1b-06.c: Remove bool variable.
	* gcc.dg/vmx/1b-07.c: Likewise.
	* gcc.dg/vmx/1b-06-ansi.c: New test for the pre-define method.
	* gcc.dg/vmx/1b-07-ansi.c: Likewise.

From-SVN: r137775
---
 libcpp/macro.c | 55 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 37 insertions(+), 18 deletions(-)

(limited to 'libcpp/macro.c')

diff --git a/libcpp/macro.c b/libcpp/macro.c
index edc2856..1563d78 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -1251,16 +1251,21 @@ cpp_get_token (cpp_reader *pfile)
 
       if (!(node->flags & NODE_DISABLED))
 	{
-	  int ret;
+	  int ret = 0;
 	  /* If not in a macro context, and we're going to start an
 	     expansion, record the location.  */
 	  if (can_set && !context->macro)
 	    pfile->invocation_location = result->src_loc;
 	  if (pfile->state.prevent_expansion)
 	    break;
-	  ret = enter_macro_context (pfile, node, result);
-	  if (ret)
-	    {
+
+	  /* Conditional macros require that a predicate be evaluated
+	     first.  */
+	  if (((!(node->flags & NODE_CONDITIONAL))
+	       || (pfile->cb.macro_to_expand
+		   && (node = pfile->cb.macro_to_expand (pfile, result))))
+	      && (ret = enter_macro_context (pfile, node, result)))
+ 	    {
 	      if (pfile->state.in_directive || ret == 2)
 		continue;
 	      return padding_token (pfile, result);
@@ -1338,26 +1343,31 @@ cpp_scan_nooutput (cpp_reader *pfile)
   pfile->state.prevent_expansion--;
 }
 
+/* Step back one or more tokens obtained from the lexer.  */
+void
+_cpp_backup_tokens_direct (cpp_reader *pfile, unsigned int count)
+{
+  pfile->lookaheads += count;
+  while (count--)
+    {
+      pfile->cur_token--;
+      if (pfile->cur_token == pfile->cur_run->base
+          /* Possible with -fpreprocessed and no leading #line.  */
+          && pfile->cur_run->prev != NULL)
+        {
+          pfile->cur_run = pfile->cur_run->prev;
+          pfile->cur_token = pfile->cur_run->limit;
+        }
+    }
+}
+
 /* Step back one (or more) tokens.  Can only step back more than 1 if
    they are from the lexer, and not from macro expansion.  */
 void
 _cpp_backup_tokens (cpp_reader *pfile, unsigned int count)
 {
   if (pfile->context->prev == NULL)
-    {
-      pfile->lookaheads += count;
-      while (count--)
-	{
-	  pfile->cur_token--;
-	  if (pfile->cur_token == pfile->cur_run->base
-	      /* Possible with -fpreprocessed and no leading #line.  */
-	      && pfile->cur_run->prev != NULL)
-	    {
-	      pfile->cur_run = pfile->cur_run->prev;
-	      pfile->cur_token = pfile->cur_run->limit;
-	    }
-	}
-    }
+    _cpp_backup_tokens_direct (pfile, count);
   else
     {
       if (count != 1)
@@ -1383,6 +1393,11 @@ warn_of_redefinition (cpp_reader *pfile, const cpp_hashnode *node,
   if (node->flags & NODE_WARN)
     return true;
 
+  /* Redefinitions of conditional (context-sensitive) macros, on
+     the other hand, must be allowed silently.  */
+  if (node->flags & NODE_CONDITIONAL)
+    return false;
+
   /* Redefinition of a macro is allowed if and only if the old and new
      definitions are the same.  (6.10.3 paragraph 2).  */
   macro1 = node->value.macro;
@@ -1815,6 +1830,10 @@ _cpp_create_definition (cpp_reader *pfile, cpp_hashnode *node)
       && ustrcmp (NODE_NAME (node), (const uchar *) "__STDC_CONSTANT_MACROS"))
     node->flags |= NODE_WARN;
 
+  /* If user defines one of the conditional macros, remove the
+     conditional flag */
+  node->flags &= ~NODE_CONDITIONAL;
+
   return ok;
 }
 
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