Add ability to remap file names in __FILE__, etc (PR other/70268)

This commit adds the -fmacro-prefix-map option that allows remapping of file
names in __FILE__, __BASE_FILE__, and __builtin_FILE(), similar to how
-fdebug-prefix-map allows to do the same for debug information.

Additionally, it adds -ffile-prefix-map which can be used to specify both
mappings with a single option (and, should we need to add more -f*-prefix-map
options in the future, those as well).

libcpp/ChangeLog:

2018-01-18  Boris Kolpackov  <boris@codesynthesis.com>

        PR other/70268
        * include/cpplib.h (cpp_callbacks::remap_filename): New callback.
        * libcpp/macro.c (_cpp_builtin_macro_text): Call remap_filename for
        __FILE__ and __BASE_FILE__.


gcc/ChangeLog:

2018-01-18  Boris Kolpackov  <boris@codesynthesis.com>

        PR other/70268
        * common.opt: (-ffile-prefix-map): New option.
        * opts.c (common_handle_option): Defer it.
        * opts-global.c (handle_common_deferred_options): Handle it.
        * debug.h (remap_debug_filename, add_debug_prefix_map): Move to...
        * file-prefix-map.h: New file.
        (remap_debug_filename, add_debug_prefix_map): ...here.
        (add_macro_prefix_map, add_file_prefix_map, remap_macro_filename): New.
        * final.c (debug_prefix_map, add_debug_prefix_map
        remap_debug_filename): Move to...
        * file-prefix-map.c: New file.
        (file_prefix_map, add_prefix_map, remap_filename) ...here and rename,
        generalize, get rid of alloca(), use strrchr() instead of strchr().
        (add_macro_prefix_map, add_debug_prefix_map, add_file_prefix_map):
        Implement in terms of add_prefix_map().
        (remap_macro_filename, remap_debug_filename): Implement in term of
        remap_filename().
        * Makefile.in (OBJS, PLUGIN_HEADERS): Add new files.
        * builtins.c (fold_builtin_FILE): Call remap_macro_filename().
        * dbxout.c: Include file-prefix-map.h.
        * varasm.c: Likewise.
        * vmsdbgout.c: Likewise.
        * xcoffout.c: Likewise.
        * dwarf2out.c: Likewise plus omit new options from DW_AT_producer.
        * doc/cppopts.texi (-fmacro-prefix-map): Document.
        * doc/invoke.texi (-ffile-prefix-map): Document.
	(-fdebug-prefix-map): Update description.


gcc/c-family/ChangeLog:

2018-01-18  Boris Kolpackov  <boris@codesynthesis.com>

        PR other/70268
        * c-family/c.opt (-fmacro-prefix-map): New option.
        * c-family/c-opts.c (c_common_handle_option): Handle it.
        * c-family/c-lex.c (init_c_lex): Set remap_filename cpp callback.
        * c-family/c-ppoutput.c (init_pp_output): Likewise.


gcc/testsuite/ChangeLog:

2018-01-18  Boris Kolpackov  <boris@codesynthesis.com>

        PR other/70268
        * c-c++-common/ffile-prefix-map.c: New test.
        * c-c++-common/fmacro-prefix-map.c: New test.
        * c-c++-common/cpp/ffile-prefix-map.c: New test.
        * c-c++-common/cpp/fmacro-prefix-map.c: New test.

From-SVN: r256847

3 files changed, 17 insertions, 4 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index b69e364..5d2aa26 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,10 @@
+2018-01-18  Boris Kolpackov  <boris@codesynthesis.com>
+
+        PR other/70268
+        * include/cpplib.h (cpp_callbacks::remap_filename): New callback.
+        * libcpp/macro.c (_cpp_builtin_macro_text): Call remap_filename for
+        __FILE__ and __BASE_FILE__.
+
 2018-01-10  Kelvin Nilsen  <kelvin@gcc.gnu.org>
 
 	* lex.c (search_line_fast): Remove illegal coercion of an
@@ -19,7 +26,7 @@
 2017-12-14  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* internal.h (maybe_print_line): Change signature.
-	
+
 2017-12-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/79228
@@ -714,9 +721,9 @@
 	* init.c (cpp_init_source_date_epoch): New function.
 	* internal.h: Added source_date_epoch variable to struct
 	cpp_reader to store a reproducible date.
-	* macro.c (_cpp_builtin_macro_text): Set pfile->date timestamp from 
-	pfile->source_date_epoch instead of localtime if source_date_epoch is 
-	set, to be used for __DATE__ and __TIME__ macros to help reproducible 
+	* macro.c (_cpp_builtin_macro_text): Set pfile->date timestamp from
+	pfile->source_date_epoch instead of localtime if source_date_epoch is
+	set, to be used for __DATE__ and __TIME__ macros to help reproducible
 	builds.
 
 2016-04-13  Bernd Schmidt  <bschmidt@redhat.com>
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 7cc40c6..9814d0d 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -622,6 +622,10 @@ struct cpp_callbacks
      C++-style comments it does not include the terminating newline.  */
   void (*comment) (cpp_reader *, source_location, const unsigned char *,
 		   size_t);
+
+  /* Callback for filename remapping in __FILE__ and __BASE_FILE__ macro
+     expansions.  */
+  const char *(*remap_filename) (const char*);
 };
 
 #ifdef VMS
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 0f9f063..c5f3ffd 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -450,6 +450,8 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node,
 	    if (!name)
 	      abort ();
 	  }
+	if (pfile->cb.remap_filename)
+	  name = pfile->cb.remap_filename (name);
 	len = strlen (name);
 	buf = _cpp_unaligned_alloc (pfile, len * 2 + 3);
 	result = buf;