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

1 files changed, 13 insertions, 0 deletions

diff --git a/gcc/doc/cppopts.texi b/gcc/doc/cppopts.texi
index b2252367ef5..ef3a0b2f196 100644
--- a/gcc/doc/cppopts.texi
+++ b/gcc/doc/cppopts.texi
@@ -583,6 +583,19 @@ correct column numbers in warnings or errors, even if tabs appear on the
 line.  If the value is less than 1 or greater than 100, the option is
 ignored.  The default is 8.
 
+@item -fdebug-cpp
+@opindex fdebug-cpp
+This option is only useful for debugging GCC.  When used with
+@option{-E}, dumps debugging information about location maps.  Every
+token in the output is preceded by the dump of the map its location
+belongs to.  The dump of the map holding the location of a token would
+be:
+@quotation
+@{@samp{P}:@file{/file/path};@samp{F}:@file{/includer/path};@samp{L}:@var{line_num};@samp{C}:@var{col_num};@samp{S}:@var{system_header_p};@samp{M}:@var{map_address};@samp{E}:@var{macro_expansion_p},@samp{loc}:@var{location}@}
+@end quotation
+
+When used without @option{-E}, this option has no effect.
+
 @item -ftrack-macro-expansion@r{[}=@var{level}@r{]}
 @opindex ftrack-macro-expansion
 Track locations of tokens across macro expansions. This allows the