re PR preprocessor/39646 (__FILE__ breaks for empty file name)

libcpp:
	PR preprocessor/39646
	* include/line-map.h (enum lc_reason): Add LC_RENAME_VERBATIM.
	* line-map.c (linemap_add): Handle LC_RENAME_VERBATIM.
	* directives.c (do_line, do_linemarker): Use LC_RENAME_VERBATIM in
	place of LC_RENAME.

gcc/testsuite:
	* gcc.dg/cpp/line8.c: New test.

From-SVN: r146319

6 files changed, 32 insertions, 5 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 58ea487..075c7b5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2009-04-18  Joseph Myers  <joseph@codesourcery.com>
 
+	PR preprocessor/39646
+	* gcc.dg/cpp/line8.c: New test.
+
+2009-04-18  Joseph Myers  <joseph@codesourcery.com>
+
 	PR preprocessor/39647
 	* gcc.dg/cpp/line7.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/cpp/line8.c b/gcc/testsuite/gcc.dg/cpp/line8.c
new file mode 100644
index 0000000..5aeb26c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/line8.c
@@ -0,0 +1,10 @@
+/* Test that "" is not specially interpreted as "<stdin>" in a #line
+   directive.  PR 39646.  */
+
+/* { dg-do compile } */
+/* { dg-options "-pedantic-errors" } */
+
+extern int x;
+
+#line 24 ""
+extern char z[sizeof __FILE__ == 1];
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index ce7bbe0..ab72fa6 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,5 +1,13 @@
 2009-04-18  Joseph Myers  <joseph@codesourcery.com>
 
+	PR preprocessor/39646
+	* include/line-map.h (enum lc_reason): Add LC_RENAME_VERBATIM.
+	* line-map.c (linemap_add): Handle LC_RENAME_VERBATIM.
+	* directives.c (do_line, do_linemarker): Use LC_RENAME_VERBATIM in
+	place of LC_RENAME.
+
+2009-04-18  Joseph Myers  <joseph@codesourcery.com>
+
 	PR preprocessor/39647
 	* directives.c (check_eol): Add parameter expand.
 	(do_undef, parse_include, do_line, do_linemarker, do_ident,
diff --git a/libcpp/directives.c b/libcpp/directives.c
index 9cb8506..9e26732 100644
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -924,7 +924,7 @@ do_line (cpp_reader *pfile)
     }
 
   skip_rest_of_line (pfile);
-  _cpp_do_file_change (pfile, LC_RENAME, new_file, new_lineno,
+  _cpp_do_file_change (pfile, LC_RENAME_VERBATIM, new_file, new_lineno,
 		       map_sysp);
 }
 
@@ -940,7 +940,7 @@ do_linemarker (cpp_reader *pfile)
   const char *new_file = map->to_file;
   linenum_type new_lineno;
   unsigned int new_sysp = map->sysp;
-  enum lc_reason reason = LC_RENAME;
+  enum lc_reason reason = LC_RENAME_VERBATIM;
   int flag;
   bool wrapped;
 
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 501a193..56ab79a 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -31,8 +31,9 @@ along with this program; see the file COPYING3.  If not see
    when including a new file, e.g. a #include directive in C.
    LC_LEAVE is when reaching a file's end.  LC_RENAME is when a file
    name or line number changes for neither of the above reasons
-   (e.g. a #line directive in C).  */
-enum lc_reason {LC_ENTER = 0, LC_LEAVE, LC_RENAME};
+   (e.g. a #line directive in C); LC_RENAME_VERBATIM is like LC_RENAME
+   but a filename of "" is not specially interpreted as standard input.  */
+enum lc_reason {LC_ENTER = 0, LC_LEAVE, LC_RENAME, LC_RENAME_VERBATIM};
 
 /* The type of line numbers.  */
 typedef unsigned int linenum_type;
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index cce699f..553cc2a 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -109,9 +109,12 @@ linemap_add (struct line_maps *set, enum lc_reason reason,
 
   map = &set->maps[set->used];
 
-  if (to_file && *to_file == '\0')
+  if (to_file && *to_file == '\0' && reason != LC_RENAME_VERBATIM)
     to_file = "<stdin>";
 
+  if (reason == LC_RENAME_VERBATIM)
+    reason = LC_RENAME;
+
   /* If we don't keep our line maps consistent, we can easily
      segfault.  Don't rely on the client to do it for us.  */
   if (set->depth == 0)