Support -fdebug-cpp option

This patch adds -fdebug-cpp option. When used with -E this dumps the
relevant macro map before every single token. This clutters the output
a lot but has proved to be invaluable in tracking some bugs during the
development of the virtual location support.

Co-Authored-By: Dodji Seketeli <dodji@redhat.com>

From-SVN: r180084

4 files changed, 53 insertions, 0 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 5eab7b0..bd86466 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,6 +1,13 @@
 2011-10-15  Tom Tromey  <tromey@redhat.com>
 	    Dodji Seketeli  <dodji@redhat.com>
 
+	* include/cpplib.h (struct cpp_options)<debug>: New struct member.
+	* include/line-map.h (linemap_dump_location): Declare ...
+	* line-map.c (linemap_dump_location): ... new function.
+
+2011-10-15  Tom Tromey  <tromey@redhat.com>
+	    Dodji Seketeli  <dodji@redhat.com>
+
 	* include/cpplib.h (struct cpp_options)<track_macro_expansion>:
 	New option.
 	* internal.h (struct macro_context): New struct.
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 3e01c11..825bf2f 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -392,6 +392,10 @@ struct cpp_options
   /* Nonzero means we're looking at already preprocessed code, so don't
      bother trying to do macro expansion and whatnot.  */
   unsigned char preprocessed;
+  
+  /* Nonzero means we are going to emit debugging logs during
+     preprocessing.  */
+  unsigned char debug;
 
   /* Nonzero means we are tracking locations of tokens involved in
      macro expansion. 1 Means we track the location in degraded mode
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 724f3f0..04a523c 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -675,4 +675,8 @@ expanded_location linemap_expand_location_full (struct line_maps *,
 						source_location loc,
 						enum location_resolution_kind lrk);
 
+/* Dump debugging information about source location LOC into the file
+   stream STREAM. SET is the line map set LOC comes from.  */
+void linemap_dump_location (struct line_maps *, source_location, FILE *);
+
 #endif /* !LIBCPP_LINE_MAP_H  */
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index fe07c16..3dbaeab 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -1105,3 +1105,41 @@ linemap_expand_location_full (struct line_maps *set,
   xloc = linemap_expand_location (map, loc);
   return xloc;
 }
+
+/* Dump debugging information about source location LOC into the file
+   stream STREAM. SET is the line map set LOC comes from.  */
+
+void
+linemap_dump_location (struct line_maps *set,
+		       source_location loc,
+		       FILE *stream)
+{
+  const struct line_map *map;
+  source_location location;
+  const char *path, *from;
+  int l,c,s,e;
+
+  if (loc == 0)
+    return;
+
+  location =
+    linemap_resolve_location (set, loc, LRK_MACRO_DEFINITION_LOCATION, &map);
+  path = LINEMAP_FILE (map);
+
+  l = SOURCE_LINE (map, location);
+  c = SOURCE_COLUMN (map, location);
+  s = LINEMAP_SYSP (map) != 0;
+  e = location != loc;
+
+  if (e)
+    from = "N/A";
+  else
+    from = (INCLUDED_FROM (set, map))
+      ? LINEMAP_FILE (INCLUDED_FROM (set, map))
+      : "<NULL>";
+
+  /* P: path, L: line, C: column, S: in-system-header, M: map address,
+     E: macro expansion?.   */
+  fprintf (stream, "{P:%s;F:%s;L:%d;C:%d;S:%d;M:%p;E:%d,LOC:%d}",
+	   path, from, l, c, s, (void*)map, e, loc);
+}