Support location tracking for built-in macro tokens

When a built-in macro is expanded, the location of the token in the
epansion list is the location of the expansion point of the built-in
macro.

This patch creates a virtual location for that token instead,
effectively tracking locations of tokens resulting from built-in macro
tokens.

libcpp/
	* include/line-map.h (line_maps::builtin_location): New data
	member.
	(line_map_init): Add a new parameter to initialize the new
	line_maps::builtin_location data member.
	* line-map.c (linemap_init): Initialize the
	line_maps::builtin_location data member.
	* macro.c (builtin_macro): Create a macro map and track the token
	resulting from the expansion of a built-in macro.
gcc/
	* input.h (is_location_from_builtin_token): New function
	declaration.
	* input.c (is_location_from_builtin_token): New function
	definition.
	* toplev.c (general_init): Tell libcpp what the pre-defined
	spelling location for built-in tokens is.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

From-SVN: r212637

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/input.c b/gcc/input.c
index 63cd062..f3fd0e9 100644
--- a/gcc/input.c
+++ b/gcc/input.c
@@ -713,6 +713,22 @@ location_get_source_line (expanded_location xloc,
   return read ? buffer : NULL;
 }
 
+/* Test if the location originates from the spelling location of a
+   builtin-tokens.  That is, return TRUE if LOC is a (possibly
+   virtual) location of a built-in token that appears in the expansion
+   list of a macro.  Please note that this function also works on
+   tokens that result from built-in tokens.  For instance, the
+   function would return true if passed a token "4" that is the result
+   of the expansion of the built-in __LINE__ macro.  */
+bool
+is_location_from_builtin_token (source_location loc)
+{
+  const line_map *map = NULL;
+  loc = linemap_resolve_location (line_table, loc,
+				  LRK_SPELLING_LOCATION, &map);
+  return loc == BUILTINS_LOCATION;
+}
+
 /* Expand the source location LOC into a human readable location.  If
    LOC is virtual, it resolves to the expansion point of the involved
    macro.  If LOC resolves to a builtin location, the file name of the