[PATCH] For flex: define YY_FATAL_ERROR, rename fprintf -> parser_fprintf

[Pedro Alves <palves@redhat.com>]

Switching GDB to make use of gnulib's C++ namespace support mode
revealed these direct uses of fprintf in the Ada lexer:

 In file included from ..../src/gdb/ada-exp.y:731:0:
 ada-lex.c: In function ‘void yy_fatal_error(const char*)’:
 ada-lex.c:2358:41: error: call to ‘fprintf’ declared with attribute warning: The symbol ::fprintf refers to the system function. Use gnulib::fprintf instead. [-Werror]
     (void) fprintf( stderr, "%s\n", msg );
					  ^

yy_fatal_error looks like this:

 static void yy_fatal_error (yyconst char* msg )
 {
			 (void) fprintf( stderr, "%s\n", msg );
	 exit( YY_EXIT_FAILURE );
 }

We can define YY_FATAL_ERROR to override that default implementation.
I think it's a good idea to do that and call internal_error instead of
exiting gdb.

However, the default implementation is still unconditionally compiled
in, so we need to handle that fprintf somehow too.  gnulib's C++
namespace support adds that useful warning shown above, breaking the
build if we don't do anything here.

So this commit uses sed to replace fprintf calls with parser_fprintf
calls, like we already do to rewire malloc to xmalloc, etc.

gdb/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* Makefile.in (.l.c): Replace fprintf calls with parser_fprintf
	calls.
	* yy-remap.h (YY_FATAL_ERROR): Define.
---
 gdb/Makefile.in | 14 ++++++++++----
 gdb/yy-remap.h  |  2 ++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 3876cd9..c473472 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1875,10 +1875,15 @@ po/$(PACKAGE).pot: force
 # LANG-exp.c is generated in objdir from LANG-exp.y if it doesn't
 # exist in srcdir, then compiled in objdir to LANG-exp.o.  If we
 # said LANG-exp.c rather than ./c-exp.c some makes would
-# sometimes re-write it into $(srcdir)/c-exp.c.  Remove bogus
-# decls for malloc/realloc/free which conflict with everything else.
-# Strictly speaking c-exp.c should therefore depend on
-# Makefile.in, but that was a pretty big annoyance.
+# sometimes re-write it into $(srcdir)/c-exp.c.
+#
+# Remove bogus decls for malloc/realloc/free which conflict with
+# everything else.
+#
+# Replace calls to fprintf in order to redirect stderr -> gdb_stderr.
+#
+# Strictly speaking c-exp.c should therefore depend on Makefile.in,
+# but that was a pretty big annoyance.
 
 .SUFFIXES: .y .l
 .y.c:
@@ -1909,6 +1914,7 @@ po/$(PACKAGE).pot: force
 	        -e 's/\([^x]\)realloc/\1xrealloc/g' \
 	        -e 's/\([ \t;,(]\)free\([ \t]*[&(),]\)/\1xfree\2/g' \
 	        -e 's/\([ \t;,(]\)free$$/\1xfree/g' \
+	        -e 's/\([ \t;,(]\)fprintf/\1parser_fprintf/g' \
 		-e 's/yy_flex_xrealloc/yyxrealloc/g' \
 	      < $@ > $@.new && \
 	    rm -f $@ && \
diff --git a/gdb/yy-remap.h b/gdb/yy-remap.h
index 71fa946..d96f8e6 100644
--- a/gdb/yy-remap.h
+++ b/gdb/yy-remap.h
@@ -90,3 +90,5 @@
 #endif
 
 #define YYFPRINTF parser_fprintf
+
+#define YY_FATAL_ERROR(msg) internal_error (__FILE__, __LINE__, msg)
-- 
2.5.5