Replace line_map union with C++ class hierarchy

gcc/ChangeLog:
	* diagnostic.c (diagnostic_report_current_module): Strengthen
	local "new_map" from const line_map * to
	const line_map_ordinary *.
	* genmatch.c (error_cb): Likewise for local "map".
	(output_line_directive): Likewise for local "map".
	* input.c (expand_location_1): Likewise for local "map".
	Pass NULL rather than &map to
	linemap_unwind_to_first_non_reserved_loc, since the value is never
	read from there, and the value written back not read from here.
	(is_location_from_builtin_token): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(dump_location_info): Strengthen locals "map" from
	line_map *, one to const line_map_ordinary *, the other
	to const line_map_macro *.
	* tree-diagnostic.c (loc_map_pair): Strengthen field "map" from
	const line_map * to const line_map_macro *.
	(maybe_unwind_expanded_macro_loc): Add a call to
	linemap_check_macro when writing to the "map" field of the
	loc_map_pair.
	Introduce local const line_map_ordinary * "ord_map", using it in
	place of "map" in the part of the function where we know we have
	an ordinary map.  Strengthen local "m" from const line_map * to
	const line_map_ordinary *.

gcc/ada/ChangeLog:
	* gcc-interface/trans.c (Sloc_to_locus1): Strenghthen local "map"
	from line_map * to line_map_ordinary *.

gcc/c-family/ChangeLog:
	* c-common.h (fe_file_change): Strengthen param from
	const line_map * to const line_map_ordinary *.
	(pp_file_change): Likewise.
	* c-lex.c (fe_file_change): Likewise.
	(cb_define): Use linemap_check_ordinary when invoking
	SOURCE_LINE.
	(cb_undef): Likewise.
	* c-opts.c (c_finish_options): Use linemap_check_ordinary when
	invoking cb_file_change.
	(c_finish_options): Likewise.
	(push_command_line_include): Likewise.
	(cb_file_change): Strengthen param "new_map" from
	const line_map * to const line_map_ordinary *.
	* c-ppoutput.c (cb_define): Likewise for local "map".
	(pp_file_change): Likewise for param "map" and local "from".

gcc/fortran/ChangeLog:
	* cpp.c (maybe_print_line): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(cb_file_change): Likewise for param "map" and local "from".
	(cb_line_change): Likewise for local "map".

libcpp/ChangeLog:
	* directives.c (do_line): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(do_linemarker): Likewise.
	(_cpp_do_file_change): Assert that we're not dealing with
	a macro map.  Introduce local "ord_map" via a call to
	linemap_check_ordinary, guarded within the check for
	non-NULL.  Use it for typesafety.
	* files.c (cpp_make_system_header): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	* include/cpplib.h (struct cpp_callbacks): Likewise for second
	parameter of "file_change" callback.
	* include/line-map.h (struct line_map): Convert from a struct
	containing a union to a base class.
	(struct line_map_ordinary): Convert to a subclass of line_map.
	(struct line_map_macro): Likewise.
	(linemap_check_ordinary): Strengthen return type from line_map *
	to line_map_ordinary *, and add a const-variant.
	(linemap_check_macro): New pair of functions.
	(ORDINARY_MAP_STARTING_LINE_NUMBER): Strengthen param from
	const line_map * to const line_map_ordinary *, eliminating call
	to linemap_check_ordinary.  Likewise for the non-const variant.
	(ORDINARY_MAP_INCLUDER_FILE_INDEX): Likewise.
	(ORDINARY_MAP_IN_SYSTEM_HEADER_P): Likewise.
	(ORDINARY_MAP_NUMBER_OF_COLUMN_BITS): Likewise.
	(ORDINARY_MAP_FILE_NAME): Likewise.
	(MACRO_MAP_MACRO): Strengthen param from const line_map * to
	const line_map_macro *.  Likewise for the non-const variant.
	(MACRO_MAP_NUM_MACRO_TOKENS): Likewise.
	(MACRO_MAP_LOCATIONS): Likewise.
	(MACRO_MAP_EXPANSION_POINT_LOCATION): Likewise.
	(struct maps_info): Replace with...
	(struct maps_info_ordinary):...this and...
	(struct maps_info_macro): ...this.
	(struct line_maps): Convert fields "info_ordinary" and
	"info_macro" to the above new structs.
	(LINEMAPS_MAP_INFO): Delete both functions.
	(LINEMAPS_MAPS): Likewise.
	(LINEMAPS_ALLOCATED): Rewrite both variants to avoid using
	LINEMAPS_MAP_INFO.
	(LINEMAPS_USED): Likewise.
	(LINEMAPS_CACHE): Likewise.
	(LINEMAPS_MAP_AT): Likewise.
	(LINEMAPS_ORDINARY_MAPS): Strengthen return type from line_map *
	to line_map_ordinary *.
	(LINEMAPS_ORDINARY_MAP_AT): Likewise.
	(LINEMAPS_LAST_ORDINARY_MAP): Likewise.
	(LINEMAPS_LAST_ALLOCATED_ORDINARY_MAP): Likewise.
	(LINEMAPS_MACRO_MAPS): Strengthen return type from line_map * to
	line_map_macro *.
	(LINEMAPS_MACRO_MAP_AT): Likewise.
	(LINEMAPS_LAST_MACRO_MAP): Likewise.
	(LINEMAPS_LAST_ALLOCATED_MACRO_MAP): Likewise.
	(linemap_map_get_macro_name): Strengthen param from
	const line_map * to const line_map_macro *.
	(SOURCE_LINE): Strengthen first param from const line_map * to
	const line_map_ordinary *, removing call to
	linemap_check_ordinary.
	(SOURCE_COLUMN): Likewise.
	(LAST_SOURCE_LINE_LOCATION): Likewise.
	(LAST_SOURCE_LINE): Strengthen first param from const line_map *
	to const line_map_ordinary *.
	(LAST_SOURCE_COLUMN): Likewise.
	(INCLUDED_FROM): Strengthen return type from line_map * to
	line_map_ordinary *., and second param from const line_map *
	to const line_map_ordinary *, removing call to
	linemap_check_ordinary.
	(MAIN_FILE_P): Strengthen param from const line_map * to
	const line_map_ordinary *, removing call to
	linemap_check_ordinary.
	(linemap_position_for_line_and_column): Strengthen param from
	const line_map * to const line_map_ordinary *.
	(LINEMAP_FILE): Strengthen param from const line_map * to
	const line_map_ordinary *, removing call to
	linemap_check_ordinary.
	(LINEMAP_LINE): Likewise.
	(LINEMAP_SYSP): Likewise.
	(linemap_resolve_location): Strengthen final param from
	const line_map ** to const line_map_ordinary **.
	* internal.h (CPP_INCREMENT_LINE): Likewise for local "map".
	(linemap_enter_macro): Strengthen return type from
	const line_map * to const line_map_macro *.
	(linemap_add_macro_token): Likewise for first param.
	* line-map.c (linemap_check_files_exited): Strengthen local "map"
	from const line_map * to const line_map_ordinary *.
	(new_linemap): Introduce local "map_size" and use it when
	calculating how large the buffer should be.  Rewrite based
	on change of info_macro and info_ordinary into distinct types.
	(linemap_add): Strengthen locals "map" and "from" from line_map *
	to line_map_ordinary *.
	(linemap_enter_macro): Strengthen return type from
	const line_map * to const line_map_macro *, and local "map" from
	line_map * to line_map_macro *.
	(linemap_add_macro_token): Strengthen param "map" from
	const line_map * to const line_map_macro *.
	(linemap_line_start): Strengthen local "map" from line_map * to
	line_map_ordinary *.
	(linemap_position_for_column): Likewise.
	(linemap_position_for_line_and_column): Strengthen first param
	from const line_map * to const line_map_ordinary *.
	(linemap_position_for_loc_and_offset): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(linemap_ordinary_map_lookup): Likewise for return type and locals
	"cached" and "result".
	(linemap_macro_map_lookup): Strengthen return type and locals
	"cached" and "result" from const line_map * to
	const line_map_macro *.
	(linemap_macro_map_loc_to_exp_point): Likewise for param "map".
	(linemap_macro_map_loc_to_def_point): Likewise.
	(linemap_macro_map_loc_unwind_toward_spelling): Likewise.
	(linemap_get_expansion_line): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(linemap_get_expansion_filename): Likewise.
	(linemap_map_get_macro_name): Strengthen param from
	const line_map * to const line_map_macro *.
	(linemap_location_in_system_header_p): Add call to
	linemap_check_ordinary in region guarded by
	!linemap_macro_expansion_map_p.  Introduce local "macro_map" via
	linemap_check_macro in other region, using it in place of "map"
	for typesafety.
	(first_map_in_common_1): Add calls to linemap_check_macro.
	(trace_include): Strengthen param "map" from const line_map * to
	const line_map_ordinary *.
	(linemap_macro_loc_to_spelling_point): Strengthen final param from
	const line_map ** to const line_map_ordinary **.  Replace a
	C-style cast with a const_cast, and add calls to
	linemap_check_macro and linemap_check_ordinary.
	(linemap_macro_loc_to_def_point): Likewise.
	(linemap_macro_loc_to_exp_point): Likewise.
	(linemap_resolve_location): Strengthen final param from
	const line_map ** to const line_map_ordinary **.
	(linemap_unwind_toward_expansion): Introduce local "macro_map" via
	a checked cast and use it in place of *map.
	(linemap_unwind_to_first_non_reserved_loc): Strengthen local
	"map1" from const line_map * to const line_map_ordinary *.
	(linemap_expand_location): Introduce local "ord_map" via a checked
	cast and use it in place of map.
	(linemap_dump): Make local "map" const.  Strengthen local
	"includer_map" from line_map * to const line_map_ordinary *.
	Introduce locals "ord_map" and "macro_map" via checked casts and
	use them in place of "map" for typesafety.
	(linemap_dump_location): Strengthen local "map" from
	const line_map * to const line_map_ordinary *.
	(linemap_get_file_highest_location): Update for elimination of
	union.
	(linemap_get_statistics): Strengthen local "cur_map" from
	line_map * to const line_map_macro *.  Update uses of sizeof to
	use the appropriate line_map subclasses.
	* macro.c (_cpp_warn_if_unused_macro): Add call to
	linemap_check_ordinary.
	(builtin_macro): Strengthen local "map" from const line_map * to
	const line_map_macro *.
	(enter_macro_context): Likewise.
	(replace_args): Likewise.
	(tokens_buff_put_token_to): Likewise for param "map".
	(tokens_buff_add_token): Likewise.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@223365 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 524 insertions, 308 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 32582ddeada..d82f00894ca 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,161 @@
+2015-05-19  David Malcolm  <dmalcolm@redhat.com>
+
+	* directives.c (do_line): Strengthen local "map" from
+	const line_map * to const line_map_ordinary *.
+	(do_linemarker): Likewise.
+	(_cpp_do_file_change): Assert that we're not dealing with
+	a macro map.  Introduce local "ord_map" via a call to
+	linemap_check_ordinary, guarded within the check for
+	non-NULL.  Use it for typesafety.
+	* files.c (cpp_make_system_header): Strengthen local "map" from
+	const line_map * to const line_map_ordinary *.
+	* include/cpplib.h (struct cpp_callbacks): Likewise for second
+	parameter of "file_change" callback.
+	* include/line-map.h (struct line_map): Convert from a struct
+	containing a union to a base class.
+	(struct line_map_ordinary): Convert to a subclass of line_map.
+	(struct line_map_macro): Likewise.
+	(linemap_check_ordinary): Strengthen return type from line_map *
+	to line_map_ordinary *, and add a const-variant.
+	(linemap_check_macro): New pair of functions.
+	(ORDINARY_MAP_STARTING_LINE_NUMBER): Strengthen param from
+	const line_map * to const line_map_ordinary *, eliminating call
+	to linemap_check_ordinary.  Likewise for the non-const variant.
+	(ORDINARY_MAP_INCLUDER_FILE_INDEX): Likewise.
+	(ORDINARY_MAP_IN_SYSTEM_HEADER_P): Likewise.
+	(ORDINARY_MAP_NUMBER_OF_COLUMN_BITS): Likewise.
+	(ORDINARY_MAP_FILE_NAME): Likewise.
+	(MACRO_MAP_MACRO): Strengthen param from const line_map * to
+	const line_map_macro *.  Likewise for the non-const variant.
+	(MACRO_MAP_NUM_MACRO_TOKENS): Likewise.
+	(MACRO_MAP_LOCATIONS): Likewise.
+	(MACRO_MAP_EXPANSION_POINT_LOCATION): Likewise.
+	(struct maps_info): Replace with...
+	(struct maps_info_ordinary):...this and...
+	(struct maps_info_macro): ...this.
+	(struct line_maps): Convert fields "info_ordinary" and
+	"info_macro" to the above new structs.
+	(LINEMAPS_MAP_INFO): Delete both functions.
+	(LINEMAPS_MAPS): Likewise.
+	(LINEMAPS_ALLOCATED): Rewrite both variants to avoid using
+	LINEMAPS_MAP_INFO.
+	(LINEMAPS_USED): Likewise.
+	(LINEMAPS_CACHE): Likewise.
+	(LINEMAPS_MAP_AT): Likewise.
+	(LINEMAPS_ORDINARY_MAPS): Strengthen return type from line_map *
+	to line_map_ordinary *.
+	(LINEMAPS_ORDINARY_MAP_AT): Likewise.
+	(LINEMAPS_LAST_ORDINARY_MAP): Likewise.
+	(LINEMAPS_LAST_ALLOCATED_ORDINARY_MAP): Likewise.
+	(LINEMAPS_MACRO_MAPS): Strengthen return type from line_map * to
+	line_map_macro *.
+	(LINEMAPS_MACRO_MAP_AT): Likewise.
+	(LINEMAPS_LAST_MACRO_MAP): Likewise.
+	(LINEMAPS_LAST_ALLOCATED_MACRO_MAP): Likewise.
+	(linemap_map_get_macro_name): Strengthen param from
+	const line_map * to const line_map_macro *.
+	(SOURCE_LINE): Strengthen first param from const line_map * to
+	const line_map_ordinary *, removing call to
+	linemap_check_ordinary.
+	(SOURCE_COLUMN): Likewise.
+	(LAST_SOURCE_LINE_LOCATION): Likewise.
+	(LAST_SOURCE_LINE): Strengthen first param from const line_map *
+	to const line_map_ordinary *.
+	(LAST_SOURCE_COLUMN): Likewise.
+	(INCLUDED_FROM): Strengthen return type from line_map * to
+	line_map_ordinary *., and second param from const line_map *
+	to const line_map_ordinary *, removing call to
+	linemap_check_ordinary.
+	(MAIN_FILE_P): Strengthen param from const line_map * to
+	const line_map_ordinary *, removing call to
+	linemap_check_ordinary.
+	(linemap_position_for_line_and_column): Strengthen param from
+	const line_map * to const line_map_ordinary *.
+	(LINEMAP_FILE): Strengthen param from const line_map * to
+	const line_map_ordinary *, removing call to
+	linemap_check_ordinary.
+	(LINEMAP_LINE): Likewise.
+	(LINEMAP_SYSP): Likewise.
+	(linemap_resolve_location): Strengthen final param from
+	const line_map ** to const line_map_ordinary **.
+	* internal.h (CPP_INCREMENT_LINE): Likewise for local "map".
+	(linemap_enter_macro): Strengthen return type from
+	const line_map * to const line_map_macro *.
+	(linemap_add_macro_token): Likewise for first param.
+	* line-map.c (linemap_check_files_exited): Strengthen local "map"
+	from const line_map * to const line_map_ordinary *.
+	(new_linemap): Introduce local "map_size" and use it when
+	calculating how large the buffer should be.  Rewrite based
+	on change of info_macro and info_ordinary into distinct types.
+	(linemap_add): Strengthen locals "map" and "from" from line_map *
+	to line_map_ordinary *.
+	(linemap_enter_macro): Strengthen return type from
+	const line_map * to const line_map_macro *, and local "map" from
+	line_map * to line_map_macro *.
+	(linemap_add_macro_token): Strengthen param "map" from
+	const line_map * to const line_map_macro *.
+	(linemap_line_start): Strengthen local "map" from line_map * to
+	line_map_ordinary *.
+	(linemap_position_for_column): Likewise.
+	(linemap_position_for_line_and_column): Strengthen first param
+	from const line_map * to const line_map_ordinary *.
+	(linemap_position_for_loc_and_offset): Strengthen local "map" from
+	const line_map * to const line_map_ordinary *.
+	(linemap_ordinary_map_lookup): Likewise for return type and locals
+	"cached" and "result".
+	(linemap_macro_map_lookup): Strengthen return type and locals
+	"cached" and "result" from const line_map * to
+	const line_map_macro *.
+	(linemap_macro_map_loc_to_exp_point): Likewise for param "map".
+	(linemap_macro_map_loc_to_def_point): Likewise.
+	(linemap_macro_map_loc_unwind_toward_spelling): Likewise.
+	(linemap_get_expansion_line): Strengthen local "map" from
+	const line_map * to const line_map_ordinary *.
+	(linemap_get_expansion_filename): Likewise.
+	(linemap_map_get_macro_name): Strengthen param from
+	const line_map * to const line_map_macro *.
+	(linemap_location_in_system_header_p): Add call to
+	linemap_check_ordinary in region guarded by
+	!linemap_macro_expansion_map_p.  Introduce local "macro_map" via
+	linemap_check_macro in other region, using it in place of "map"
+	for typesafety.
+	(first_map_in_common_1): Add calls to linemap_check_macro.
+	(trace_include): Strengthen param "map" from const line_map * to
+	const line_map_ordinary *.
+	(linemap_macro_loc_to_spelling_point): Strengthen final param from
+	const line_map ** to const line_map_ordinary **.  Replace a
+	C-style cast with a const_cast, and add calls to
+	linemap_check_macro and linemap_check_ordinary.
+	(linemap_macro_loc_to_def_point): Likewise.
+	(linemap_macro_loc_to_exp_point): Likewise.
+	(linemap_resolve_location): Strengthen final param from
+	const line_map ** to const line_map_ordinary **.
+	(linemap_unwind_toward_expansion): Introduce local "macro_map" via
+	a checked cast and use it in place of *map.
+	(linemap_unwind_to_first_non_reserved_loc): Strengthen local
+	"map1" from const line_map * to const line_map_ordinary *.
+	(linemap_expand_location): Introduce local "ord_map" via a checked
+	cast and use it in place of map.
+	(linemap_dump): Make local "map" const.  Strengthen local
+	"includer_map" from line_map * to const line_map_ordinary *.
+	Introduce locals "ord_map" and "macro_map" via checked casts and
+	use them in place of "map" for typesafety.
+	(linemap_dump_location): Strengthen local "map" from
+	const line_map * to const line_map_ordinary *.
+	(linemap_get_file_highest_location): Update for elimination of
+	union.
+	(linemap_get_statistics): Strengthen local "cur_map" from
+	line_map * to const line_map_macro *.  Update uses of sizeof to
+	use the appropriate line_map subclasses.
+	* macro.c (_cpp_warn_if_unused_macro): Add call to
+	linemap_check_ordinary.
+	(builtin_macro): Strengthen local "map" from const line_map * to
+	const line_map_macro *.
+	(enter_macro_context): Likewise.
+	(replace_args): Likewise.
+	(tokens_buff_put_token_to): Likewise for param "map".
+	(tokens_buff_add_token): Likewise.
+
 2015-05-13  David Malcolm  <dmalcolm@redhat.com>
 
 	* include/line-map.h (source_location): Add a reference to
diff --git a/libcpp/directives.c b/libcpp/directives.c
index 356ec135100..1e9bc3da0fc 100644
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -912,7 +912,7 @@ static void
 do_line (cpp_reader *pfile)
 {
   struct line_maps *line_table = pfile->line_table;
-  const struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
+  const line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
 
   /* skip_rest_of_line() may cause line table to be realloc()ed so note down
      sysp right now.  */
@@ -975,7 +975,7 @@ static void
 do_linemarker (cpp_reader *pfile)
 {
   struct line_maps *line_table = pfile->line_table;
-  const struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
+  const line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
   const cpp_token *token;
   const char *new_file = ORDINARY_MAP_FILE_NAME (map);
   linenum_type new_lineno;
@@ -1065,15 +1065,20 @@ _cpp_do_file_change (cpp_reader *pfile, enum lc_reason reason,
 		     const char *to_file, linenum_type file_line,
 		     unsigned int sysp)
 {
+  linemap_assert (reason != LC_ENTER_MACRO);
   const struct line_map *map = linemap_add (pfile->line_table, reason, sysp,
 					    to_file, file_line);
+  const line_map_ordinary *ord_map = NULL;
   if (map != NULL)
-    linemap_line_start (pfile->line_table,
-			ORDINARY_MAP_STARTING_LINE_NUMBER (map),
-			127);
+    {
+      ord_map = linemap_check_ordinary (map);
+      linemap_line_start (pfile->line_table,
+			  ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map),
+			  127);
+    }
 
   if (pfile->cb.file_change)
-    pfile->cb.file_change (pfile, map);
+    pfile->cb.file_change (pfile, ord_map);
 }
 
 /* Report a warning or error detected by the program we are
diff --git a/libcpp/files.c b/libcpp/files.c
index 2f491224c6f..8c388d87d80 100644
--- a/libcpp/files.c
+++ b/libcpp/files.c
@@ -1326,7 +1326,7 @@ cpp_make_system_header (cpp_reader *pfile, int syshdr, int externc)
 {
   int flags = 0;
   const struct line_maps *line_table = pfile->line_table;
-  const struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
+  const line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
   /* 1 = system header, 2 = system header to be treated as C.  */
   if (syshdr)
     flags = 1 + (externc != 0);
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 0152ec8aa88..1b1a53ce599 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -549,7 +549,7 @@ struct cpp_callbacks
      The line_map is for the new file.  It is NULL if there is no new file.
      (In C this happens when done with <built-in>+<command line> and also
      when done with a main file.)  This can be used for resource cleanup.  */
-  void (*file_change) (cpp_reader *, const struct line_map *);
+  void (*file_change) (cpp_reader *, const line_map_ordinary *);
 
   void (*dir_change) (cpp_reader *, const char *);
   void (*include) (cpp_reader *, source_location, const unsigned char *,
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index 27aa094c997..5c04945c727 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -125,6 +125,39 @@ typedef void *(*line_map_realloc) (void *, size_t);
    for a given requested allocation.  */
 typedef size_t (*line_map_round_alloc_size_func) (size_t);
 
+/* A line_map encodes a sequence of locations.
+   There are two kinds of maps. Ordinary maps and macro expansion
+   maps, a.k.a macro maps.
+
+   A macro map encodes source locations of tokens that are part of a
+   macro replacement-list, at a macro expansion point. E.g, in:
+
+            #define PLUS(A,B) A + B
+
+   No macro map is going to be created there, because we are not at a
+   macro expansion point. We are at a macro /definition/ point. So the
+   locations of the tokens of the macro replacement-list (i.e, A + B)
+   will be locations in an ordinary map, not a macro map.
+
+   On the other hand, if we later do:
+
+        int a = PLUS (1,2);
+
+   The invocation of PLUS here is a macro expansion. So we are at a
+   macro expansion point. The preprocessor expands PLUS (1,2) and
+   replaces it with the tokens of its replacement-list: 1 + 2. A macro
+   map is going to be created to hold (or rather to map, haha ...) the
+   locations of the tokens 1, + and 2. The macro map also records the
+   location of the expansion point of PLUS. That location is mapped in
+   the map that is active right before the location of the invocation
+   of PLUS.  */
+struct GTY((tag ("0"), desc ("%h.reason == LC_ENTER_MACRO ? 2 : 1"))) line_map {
+  source_location start_location;
+
+  /* The reason for creation of this line map.  */
+  ENUM_BITFIELD (lc_reason) reason : CHAR_BIT;
+};
+
 /* An ordinary line map encodes physical source locations. Those
    physical source locations are called "spelling locations".
    
@@ -136,7 +169,7 @@ typedef size_t (*line_map_round_alloc_size_func) (size_t);
    means "entire file/line" or "unknown line/column" or "not applicable".)
 
    The highest possible source location is MAX_SOURCE_LOCATION.  */
-struct GTY(()) line_map_ordinary {
+struct GTY((tag ("1"))) line_map_ordinary : public line_map {
   const char *to_file;
   linenum_type to_line;
 
@@ -164,13 +197,9 @@ struct cpp_hashnode;
 /* A macro line map encodes location of tokens coming from a macro
    expansion.
    
-   Please note that this struct line_map_macro is a field of struct
-   line_map below, go read the comments of struct line_map below and
-   then come back here.
-   
    The offset from START_LOCATION is used to index into
    MACRO_LOCATIONS; this holds the original location of the token.  */
-struct GTY(()) line_map_macro {
+struct GTY((tag ("2"))) line_map_macro : public line_map {
   /* The cpp macro which expansion gave birth to this macro map.  */
   struct cpp_hashnode * GTY ((nested_ptr (union tree_node,
 				   "%h ? CPP_HASHNODE (GCC_IDENT_TO_HT_IDENT (%h)) : NULL",
@@ -243,44 +272,6 @@ struct GTY(()) line_map_macro {
   source_location expansion;
 };
 
-/* A line_map encodes a sequence of locations.
-   There are two kinds of maps. Ordinary maps and macro expansion
-   maps, a.k.a macro maps.
-
-   A macro map encodes source locations of tokens that are part of a
-   macro replacement-list, at a macro expansion point. E.g, in:
-
-            #define PLUS(A,B) A + B
-
-   No macro map is going to be created there, because we are not at a
-   macro expansion point. We are at a macro /definition/ point. So the
-   locations of the tokens of the macro replacement-list (i.e, A + B)
-   will be locations in an ordinary map, not a macro map.
-
-   On the other hand, if we later do:
-
-        int a = PLUS (1,2);
-
-   The invocation of PLUS here is a macro expansion. So we are at a
-   macro expansion point. The preprocessor expands PLUS (1,2) and
-   replaces it with the tokens of its replacement-list: 1 + 2. A macro
-   map is going to be created to hold (or rather to map, haha ...) the
-   locations of the tokens 1, + and 2. The macro map also records the
-   location of the expansion point of PLUS. That location is mapped in
-   the map that is active right before the location of the invocation
-   of PLUS.  */
-struct GTY(()) line_map {
-  source_location start_location;
-
-  /* The reason for creation of this line map.  */
-  ENUM_BITFIELD (lc_reason) reason : CHAR_BIT;
-
-  union map_u {
-    struct line_map_ordinary GTY((tag ("0"))) ordinary;
-    struct line_map_macro GTY((tag ("1"))) macro;
-  } GTY((desc ("%1.reason == LC_ENTER_MACRO"))) d;
-};
-
 #if defined ENABLE_CHECKING && (GCC_VERSION >= 2007)
 
 /* Assertion macro to be used in line-map code.  */
@@ -312,22 +303,44 @@ bool
 linemap_macro_expansion_map_p (const struct line_map *);
 
 /* Assert that MAP encodes locations of tokens that are not part of
-   the replacement-list of a macro expansion.  */
-inline struct line_map *
+   the replacement-list of a macro expansion, downcasting from
+   line_map * to line_map_ordinary *.  */
+
+inline line_map_ordinary *
 linemap_check_ordinary (struct line_map *map)
 {
   linemap_assert (!linemap_macro_expansion_map_p (map));
-  return map;
+  return (line_map_ordinary *)map;
 }
 
 /* Assert that MAP encodes locations of tokens that are not part of
-   the replacement-list of a macro expansion.  */
+   the replacement-list of a macro expansion, downcasting from
+   const line_map * to const line_map_ordinary *.  */
 
-inline const struct line_map *
+inline const line_map_ordinary *
 linemap_check_ordinary (const struct line_map *map)
 {
   linemap_assert (!linemap_macro_expansion_map_p (map));
-  return map;
+  return (const line_map_ordinary *)map;
+}
+
+/* Assert that MAP is a macro expansion and downcast to the appropriate
+   subclass.  */
+
+inline line_map_macro *linemap_check_macro (line_map *map)
+{
+  linemap_assert (linemap_macro_expansion_map_p (map));
+  return (line_map_macro *)map;
+}
+
+/* Assert that MAP is a macro expansion and downcast to the appropriate
+   subclass.  */
+
+inline const line_map_macro *
+linemap_check_macro (const line_map *map)
+{
+  linemap_assert (linemap_macro_expansion_map_p (map));
+  return (const line_map_macro *)map;
 }
 
 /* Read the start location of MAP, as an rvalue.  */
@@ -350,18 +363,18 @@ MAP_START_LOCATION (line_map *map)
 /* Get the starting line number of ordinary map MAP.  */
 
 inline linenum_type
-ORDINARY_MAP_STARTING_LINE_NUMBER (const line_map *map)
+ORDINARY_MAP_STARTING_LINE_NUMBER (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_line;
+  return ord_map->to_line;
 }
 
 /* Access the starting line number of ordinary map MAP by
    reference (e.g. as an lvalue).  */
 
 inline linenum_type&
-ORDINARY_MAP_STARTING_LINE_NUMBER (line_map *map)
+ORDINARY_MAP_STARTING_LINE_NUMBER (line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_line;
+  return ord_map->to_line;
 }
 
 /* Get the index of the ordinary map at whose end
@@ -370,17 +383,17 @@ ORDINARY_MAP_STARTING_LINE_NUMBER (line_map *map)
    File(s) at the bottom of the include stack have this set.  */
 
 inline int
-ORDINARY_MAP_INCLUDER_FILE_INDEX (const line_map *map)
+ORDINARY_MAP_INCLUDER_FILE_INDEX (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.included_from;
+  return ord_map->included_from;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline int&
-ORDINARY_MAP_INCLUDER_FILE_INDEX (line_map *map)
+ORDINARY_MAP_INCLUDER_FILE_INDEX (line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.included_from;
+  return ord_map->included_from;
 }
 
 /* Return a positive value if map encodes locations from a system
@@ -389,129 +402,147 @@ ORDINARY_MAP_INCLUDER_FILE_INDEX (line_map *map)
    that therefore needs to be extern "C" protected in C++.  */
 
 inline unsigned char
-ORDINARY_MAP_IN_SYSTEM_HEADER_P (const line_map *map)
+ORDINARY_MAP_IN_SYSTEM_HEADER_P (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.sysp;
+  return ord_map->sysp;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline unsigned char &
-ORDINARY_MAP_IN_SYSTEM_HEADER_P (line_map *map)
+ORDINARY_MAP_IN_SYSTEM_HEADER_P (line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.sysp;
+  return ord_map->sysp;
 }
 
 /* Get the number of the low-order source_location bits used for a
    column number within ordinary map MAP.  */
 
 inline unsigned char
-ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (const line_map *map)
+ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.column_bits;
+  return ord_map->column_bits;
 }
 
 /* Set the number of the low-order source_location bits used for a
    column number within ordinary map MAP.  */
 
 inline void
-SET_ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (line_map *map, int col_bits)
+SET_ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (line_map_ordinary *ord_map,
+					int col_bits)
 {
-  linemap_check_ordinary (map)->d.ordinary.column_bits = col_bits;
+  ord_map->column_bits = col_bits;
 }
 
 /* Get the filename of ordinary map MAP.  */
 
 inline const char *
-ORDINARY_MAP_FILE_NAME (const line_map *map)
+ORDINARY_MAP_FILE_NAME (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_file;
+  return ord_map->to_file;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline const char * &
-ORDINARY_MAP_FILE_NAME (line_map *map)
+ORDINARY_MAP_FILE_NAME (line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_file;
+  return ord_map->to_file;
 }
 
 /* Get the cpp macro whose expansion gave birth to macro map MAP.  */
 
 inline cpp_hashnode *
-MACRO_MAP_MACRO (const line_map *map)
+MACRO_MAP_MACRO (const line_map_macro *macro_map)
 {
-  return map->d.macro.macro;
+  return macro_map->macro;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline cpp_hashnode * &
-MACRO_MAP_MACRO (line_map *map)
+MACRO_MAP_MACRO (line_map_macro *macro_map)
 {
-  return map->d.macro.macro;
+  return macro_map->macro;
 }
 
 /* Get the number of tokens inside the replacement-list of the macro
    that led to macro map MAP.  */
 
 inline unsigned int
-MACRO_MAP_NUM_MACRO_TOKENS (const line_map *map)
+MACRO_MAP_NUM_MACRO_TOKENS (const line_map_macro *macro_map)
 {
-  return map->d.macro.n_tokens;
+  return macro_map->n_tokens;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline unsigned int &
-MACRO_MAP_NUM_MACRO_TOKENS (line_map *map)
+MACRO_MAP_NUM_MACRO_TOKENS (line_map_macro *macro_map)
 {
-  return map->d.macro.n_tokens;
+  return macro_map->n_tokens;
 }
 
 /* Get the array of pairs of locations within macro map MAP.
    See the declaration of line_map_macro for more information.  */
 
 inline source_location *
-MACRO_MAP_LOCATIONS (const line_map *map)
+MACRO_MAP_LOCATIONS (const line_map_macro *macro_map)
 {
-  return map->d.macro.macro_locations;
+  return macro_map->macro_locations;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline source_location * &
-MACRO_MAP_LOCATIONS (line_map *map)
+MACRO_MAP_LOCATIONS (line_map_macro *macro_map)
 {
-  return map->d.macro.macro_locations;
+  return macro_map->macro_locations;
 }
 
 /* Get the location of the expansion point of the macro map MAP.  */
 
 inline source_location
-MACRO_MAP_EXPANSION_POINT_LOCATION (const line_map *map)
+MACRO_MAP_EXPANSION_POINT_LOCATION (const line_map_macro *macro_map)
 {
-  return map->d.macro.expansion;
+  return macro_map->expansion;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
 
 inline source_location &
-MACRO_MAP_EXPANSION_POINT_LOCATION (line_map *map)
+MACRO_MAP_EXPANSION_POINT_LOCATION (line_map_macro *macro_map)
 {
-  return map->d.macro.expansion;
+  return macro_map->expansion;
 }
 
 /* The abstraction of a set of location maps. There can be several
    types of location maps. This abstraction contains the attributes
-   that are independent from the type of the map.  */
-struct GTY(()) maps_info {
-  /* This array contains the different line maps.
-     A line map is created for the following events:
-       - when a new preprocessing unit start. 
-       - when a preprocessing unit ends.
-       - when a macro expansion occurs.  */
-  struct line_map * GTY ((length ("%h.used"))) maps;
+   that are independent from the type of the map.
+
+   Essentially this is just a vector of T_linemap_subclass,
+   which can only ever grow in size.  */
+
+struct GTY(()) maps_info_ordinary {
+  /* This array contains the "ordinary" line maps, for all
+     events other than macro expansion
+     (e.g. when a new preprocessing unit starts or ends).  */
+  line_map_ordinary * GTY ((length ("%h.used"))) maps;
+
+  /* The total number of allocated maps.  */
+  unsigned int allocated;
+
+  /* The number of elements used in maps. This number is smaller
+     or equal to ALLOCATED.  */
+  unsigned int used;
+
+  unsigned int cache;
+};
+
+struct GTY(()) maps_info_macro {
+  /* This array contains the macro line maps.
+     A macro line map is created whenever a macro expansion occurs.  */
+  line_map_macro * GTY ((length ("%h.used"))) maps;
 
   /* The total number of allocated maps.  */
   unsigned int allocated;
@@ -551,9 +582,9 @@ struct GTY(()) location_adhoc_data_map {
 /* A set of chronological line_map structures.  */
 struct GTY(()) line_maps {
   
-  struct maps_info info_ordinary;
+  maps_info_ordinary info_ordinary;
 
-  struct maps_info info_macro;
+  maps_info_macro info_macro;
 
   /* Depth of the include stack, including the current file.  */
   unsigned int depth;
@@ -589,50 +620,15 @@ struct GTY(()) line_maps {
   bool seen_line_directive;
 };
 
-/* Returns the pointer to the memory region where information about
-   maps are stored in the line table SET. MACRO_MAP_P is a flag
-   telling if we want macro or ordinary maps.  */
-inline struct maps_info *
-LINEMAPS_MAP_INFO (line_maps *set, bool macro_map_p)
-{
-  return (macro_map_p
-	  ? &(set->info_macro)
-	  : &(set->info_ordinary));
-}
-
-/* As above, but preserving constness.  */
-
-inline const struct maps_info *
-LINEMAPS_MAP_INFO (const line_maps *set, bool macro_map_p)
-{
-  return (macro_map_p
-	  ? &(set->info_macro)
-	  : &(set->info_ordinary));
-}
-
-/* Returns the pointer to the memory region where maps are stored in
-   the line table SET. MAP_KIND shall be TRUE if we are interested in
-   macro maps false otherwise.  */
-inline line_map *
-LINEMAPS_MAPS (const line_maps *set, bool map_kind)
-{
-  return LINEMAPS_MAP_INFO (set, map_kind)->maps;
-}
-
-/* As above, but by reference (e.g. as an lvalue).  */
-
-inline line_map * &
-LINEMAPS_MAPS (line_maps *set, bool map_kind)
-{
-  return LINEMAPS_MAP_INFO (set, map_kind)->maps;
-}
-
 /* Returns the number of allocated maps so far. MAP_KIND shall be TRUE
    if we are interested in macro maps, FALSE otherwise.  */
 inline unsigned int
 LINEMAPS_ALLOCATED (const line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->allocated;
+  if (map_kind)
+    return set->info_macro.allocated;
+  else
+    return set->info_ordinary.allocated;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
@@ -640,7 +636,10 @@ LINEMAPS_ALLOCATED (const line_maps *set, bool map_kind)
 inline unsigned int &
 LINEMAPS_ALLOCATED (line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->allocated;
+  if (map_kind)
+    return set->info_macro.allocated;
+  else
+    return set->info_ordinary.allocated;
 }
 
 /* Returns the number of used maps so far. MAP_KIND shall be TRUE if
@@ -648,7 +647,10 @@ LINEMAPS_ALLOCATED (line_maps *set, bool map_kind)
 inline unsigned int
 LINEMAPS_USED (const line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->used;
+  if (map_kind)
+    return set->info_macro.used;
+  else
+    return set->info_ordinary.used;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
@@ -656,7 +658,10 @@ LINEMAPS_USED (const line_maps *set, bool map_kind)
 inline unsigned int &
 LINEMAPS_USED (line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->used;
+  if (map_kind)
+    return set->info_macro.used;
+  else
+    return set->info_ordinary.used;
 }
 
 /* Returns the index of the last map that was looked up with
@@ -665,7 +670,10 @@ LINEMAPS_USED (line_maps *set, bool map_kind)
 inline unsigned int
 LINEMAPS_CACHE (const line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->cache;
+  if (map_kind)
+    return set->info_macro.cache;
+  else
+    return set->info_ordinary.cache;
 }
 
 /* As above, but by reference (e.g. as an lvalue).  */
@@ -673,14 +681,20 @@ LINEMAPS_CACHE (const line_maps *set, bool map_kind)
 inline unsigned int &
 LINEMAPS_CACHE (line_maps *set, bool map_kind)
 {
-  return LINEMAPS_MAP_INFO (set, map_kind)->cache;
+  if (map_kind)
+    return set->info_macro.cache;
+  else
+    return set->info_ordinary.cache;
 }
 
 /* Return the map at a given index.  */
 inline line_map *
 LINEMAPS_MAP_AT (const line_maps *set, bool map_kind, int index)
 {
-  return &(LINEMAPS_MAPS (set, map_kind)[index]);
+  if (map_kind)
+    return &set->info_macro.maps[index];
+  else
+    return &set->info_ordinary.maps[index];
 }
 
 /* Returns the last map used in the line table SET. MAP_KIND
@@ -705,17 +719,19 @@ LINEMAPS_LAST_ALLOCATED_MAP (const line_maps *set, bool map_kind)
 
 /* Returns a pointer to the memory region where ordinary maps are
    allocated in the line table SET.  */
-inline line_map *
+inline line_map_ordinary *
 LINEMAPS_ORDINARY_MAPS (const line_maps *set)
 {
-  return LINEMAPS_MAPS (set, false);
+  return set->info_ordinary.maps;
 }
 
 /* Returns the INDEXth ordinary map.  */
-inline line_map *
+inline line_map_ordinary *
 LINEMAPS_ORDINARY_MAP_AT (const line_maps *set, int index)
 {
-  return LINEMAPS_MAP_AT (set, false, index);
+  linemap_assert (index >= 0);
+  linemap_assert ((unsigned int)index < set->info_ordinary.used);
+  return &set->info_ordinary.maps[index];
 }
 
 /* Return the number of ordinary maps allocated in the line table
@@ -751,33 +767,35 @@ LINEMAPS_ORDINARY_CACHE (line_maps *set)
 
 /* Returns a pointer to the last ordinary map used in the line table
    SET.  */
-inline line_map *
+inline line_map_ordinary *
 LINEMAPS_LAST_ORDINARY_MAP (const line_maps *set)
 {
-  return LINEMAPS_LAST_MAP (set, false);
+  return (line_map_ordinary *)LINEMAPS_LAST_MAP (set, false);
 }
 
 /* Returns a pointer to the last ordinary map allocated the line table
    SET.  */
-inline line_map *
+inline line_map_ordinary *
 LINEMAPS_LAST_ALLOCATED_ORDINARY_MAP (const line_maps *set)
 {
-  return LINEMAPS_LAST_ALLOCATED_MAP (set, false);
+  return (line_map_ordinary *)LINEMAPS_LAST_ALLOCATED_MAP (set, false);
 }
 
 /* Returns a pointer to the beginning of the region where macro maps
    are allcoated.  */
-inline line_map *
+inline line_map_macro *
 LINEMAPS_MACRO_MAPS (const line_maps *set)
 {
-  return LINEMAPS_MAPS (set, true);
+  return set->info_macro.maps;
 }
 
 /* Returns the INDEXth macro map.  */
-inline line_map *
+inline line_map_macro *
 LINEMAPS_MACRO_MAP_AT (const line_maps *set, int index)
 {
-  return LINEMAPS_MAP_AT (set, true, index);
+  linemap_assert (index >= 0);
+  linemap_assert ((unsigned int)index < set->info_macro.used);
+  return &set->info_macro.maps[index];
 }
 
 /* Returns the number of macro maps that were allocated in the line
@@ -812,10 +830,10 @@ LINEMAPS_MACRO_CACHE (line_maps *set)
 }
 
 /* Returns the last macro map used in the line table SET.  */
-inline line_map *
+inline line_map_macro *
 LINEMAPS_LAST_MACRO_MAP (const line_maps *set)
 {
-  return LINEMAPS_LAST_MAP (set, true);
+  return (line_map_macro *)LINEMAPS_LAST_MAP (set, true);
 }
 
 /* Returns the lowest location [of a token resulting from macro
@@ -829,10 +847,10 @@ LINEMAPS_MACRO_LOWEST_LOCATION (const line_maps *set)
 }
 
 /* Returns the last macro map allocated in the line table SET.  */
-inline line_map *
+inline line_map_macro *
 LINEMAPS_LAST_ALLOCATED_MACRO_MAP (const line_maps *set)
 {
-  return LINEMAPS_LAST_ALLOCATED_MAP (set, true);
+  return (line_map_macro *)LINEMAPS_LAST_ALLOCATED_MAP (set, true);
 }
 
 extern void location_adhoc_data_fini (struct line_maps *);
@@ -913,7 +931,7 @@ extern const struct line_map *linemap_lookup
 bool linemap_tracks_macro_expansion_locs_p (struct line_maps *);
 
 /* Return the name of the macro associated to MACRO_MAP.  */
-const char* linemap_map_get_macro_name (const struct line_map*);
+const char* linemap_map_get_macro_name (const line_map_macro *);
 
 /* Return a positive value if LOCATION is the locus of a token that is
    located in a system header, O otherwise. It returns 1 if LOCATION
@@ -940,37 +958,36 @@ const int RESERVED_LOCATION_COUNT = 2;
 
 /* Converts a map and a source_location to source line.  */
 inline linenum_type
-SOURCE_LINE (const struct line_map *map, source_location loc)
+SOURCE_LINE (const line_map_ordinary *ord_map, source_location loc)
 {
-  return ((loc - linemap_check_ordinary (map)->start_location)
-	  >> map->d.ordinary.column_bits) + map->d.ordinary.to_line;
+  return ((loc - ord_map->start_location)
+	  >> ord_map->column_bits) + ord_map->to_line;
 }
 
 /* Convert a map and source_location to source column number.  */
 inline linenum_type
-SOURCE_COLUMN (const struct line_map *map, source_location loc)
+SOURCE_COLUMN (const line_map_ordinary *ord_map, source_location loc)
 {
-  return ((loc - linemap_check_ordinary (map)->start_location)
-	  & ((1 << map->d.ordinary.column_bits) - 1));
+  return ((loc - ord_map->start_location)
+	  & ((1 << ord_map->column_bits) - 1));
 }
 
 /* Return the location of the last source line within an ordinary
    map.  */
 inline source_location
-LAST_SOURCE_LINE_LOCATION (const struct line_map *map)
+LAST_SOURCE_LINE_LOCATION (const line_map_ordinary *map)
 {
-  return (((linemap_check_ordinary (map)[1].start_location - 1
+  return (((map[1].start_location - 1
 	    - map->start_location)
-	   & ~((1 << map->d.ordinary.column_bits) - 1))
+	   & ~((1 << map->column_bits) - 1))
 	  + map->start_location);
 }
 
 /* Returns the last source line number within an ordinary map.  This
    is the (last) line of the #include, or other directive, that caused
    a map change.  */
-
 inline linenum_type
-LAST_SOURCE_LINE (const struct line_map *map)
+LAST_SOURCE_LINE (const line_map_ordinary *map)
 {
   return SOURCE_LINE (map, LAST_SOURCE_LINE_LOCATION (map));
 }
@@ -978,7 +995,7 @@ LAST_SOURCE_LINE (const struct line_map *map)
 /* Return the last column number within an ordinary map.  */
 
 inline linenum_type
-LAST_SOURCE_COLUMN (const struct line_map *map)
+LAST_SOURCE_COLUMN (const line_map_ordinary *map)
 {
   return SOURCE_COLUMN (map, LAST_SOURCE_LINE_LOCATION (map));
 }
@@ -986,21 +1003,20 @@ LAST_SOURCE_COLUMN (const struct line_map *map)
 /* Returns the map a given map was included from, or NULL if the map
    belongs to the main file, i.e, a file that wasn't included by
    another one.  */
-
-inline struct line_map *
-INCLUDED_FROM (struct line_maps *set, const struct line_map *map)
+inline line_map_ordinary *
+INCLUDED_FROM (struct line_maps *set, const line_map_ordinary *ord_map)
 {
-  return ((linemap_check_ordinary (map)->d.ordinary.included_from == -1)
+  return ((ord_map->included_from == -1)
 	  ? NULL
-	  : (&LINEMAPS_ORDINARY_MAPS (set)[(map)->d.ordinary.included_from]));
+	  : LINEMAPS_ORDINARY_MAP_AT (set, ord_map->included_from));
 }
 
 /* True if the map is at the bottom of the include stack.  */
 
 inline bool
-MAIN_FILE_P (const struct line_map *map)
+MAIN_FILE_P (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.included_from < 0;
+  return ord_map->included_from < 0;
 }
 
 /* Encode and return a source_location from a column number. The
@@ -1013,7 +1029,7 @@ linemap_position_for_column (struct line_maps *, unsigned int);
 /* Encode and return a source location from a given line and
    column.  */
 source_location
-linemap_position_for_line_and_column (const struct line_map *,
+linemap_position_for_line_and_column (const line_map_ordinary *,
 				      linenum_type, unsigned int);
 
 /* Encode and return a source_location starting from location LOC and
@@ -1026,16 +1042,16 @@ linemap_position_for_loc_and_offset (struct line_maps *set,
 
 /* Return the file this map is for.  */
 inline const char *
-LINEMAP_FILE (const struct line_map *map)
+LINEMAP_FILE (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_file;
+  return ord_map->to_file;
 }
 
 /* Return the line number this map started encoding location from.  */
 inline linenum_type
-LINEMAP_LINE (const struct line_map *map)
+LINEMAP_LINE (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.to_line;
+  return ord_map->to_line;
 }
 
 /* Return a positive value if map encodes locations from a system
@@ -1043,9 +1059,9 @@ LINEMAP_LINE (const struct line_map *map)
    system header and 2 if it encodes locations in a C system header
    that therefore needs to be extern "C" protected in C++.  */
 inline unsigned char
-LINEMAP_SYSP (const struct line_map *map)
+LINEMAP_SYSP (const line_map_ordinary *ord_map)
 {
-  return linemap_check_ordinary (map)->d.ordinary.sysp;
+  return ord_map->sysp;
 }
 
 /* Return a positive value if PRE denotes the location of a token that
@@ -1144,7 +1160,7 @@ enum location_resolution_kind
 source_location linemap_resolve_location (struct line_maps *,
 					  source_location loc,
 					  enum location_resolution_kind lrk,
-					  const struct line_map **loc_map);
+					  const line_map_ordinary **loc_map);
 
 /* Suppose that LOC is the virtual location of a token coming from the
    expansion of a macro M.  This function then steps up to get the
diff --git a/libcpp/internal.h b/libcpp/internal.h
index c2d08168945..95cf9c2bfd0 100644
--- a/libcpp/internal.h
+++ b/libcpp/internal.h
@@ -68,7 +68,7 @@ struct cset_converter
 
 #define CPP_INCREMENT_LINE(PFILE, COLS_HINT) do { \
     const struct line_maps *line_table = PFILE->line_table; \
-    const struct line_map *map = \
+    const struct line_map_ordinary *map = \
       LINEMAPS_LAST_ORDINARY_MAP (line_table); \
     linenum_type line = SOURCE_LINE (map, line_table->highest_line); \
     linemap_line_start (PFILE->line_table, line + 1, COLS_HINT); \
@@ -833,10 +833,10 @@ ufputs (const unsigned char *s, FILE *f)
    of the macro, rather than the the location of the first character
    of the macro.  NUM_TOKENS is the number of tokens that are part of
    the replacement-list of MACRO.  */
-const struct line_map *linemap_enter_macro (struct line_maps *,
-					    struct cpp_hashnode*,
-					    source_location,
-					    unsigned int);
+const line_map_macro *linemap_enter_macro (struct line_maps *,
+					   struct cpp_hashnode*,
+					   source_location,
+					   unsigned int);
 
 /* Create and return a virtual location for a token that is part of a
    macro expansion-list at a macro expansion point.  See the comment
@@ -860,7 +860,7 @@ const struct line_map *linemap_enter_macro (struct line_maps *,
    MACRO_DEFINITION_LOC is the location in the macro definition,
    either of the token itself or of a macro parameter that it
    replaces.  */
-source_location linemap_add_macro_token (const struct line_map *,
+source_location linemap_add_macro_token (const line_map_macro *,
 					 unsigned int,
 					 source_location,
 					 source_location);
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index fd16c24c0c6..e262df488f7 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -26,25 +26,25 @@ along with this program; see the file COPYING3.  If not see
 #include "internal.h"
 #include "hashtab.h"
 
-static void trace_include (const struct line_maps *, const struct line_map *);
-static const struct line_map * linemap_ordinary_map_lookup (struct line_maps *,
-							    source_location);
-static const struct line_map* linemap_macro_map_lookup (struct line_maps *,
-							source_location);
+static void trace_include (const struct line_maps *, const line_map_ordinary *);
+static const line_map_ordinary * linemap_ordinary_map_lookup (struct line_maps *,
+							      source_location);
+static const line_map_macro* linemap_macro_map_lookup (struct line_maps *,
+						       source_location);
 static source_location linemap_macro_map_loc_to_def_point
-(const struct line_map*, source_location);
+(const line_map_macro *, source_location);
 static source_location linemap_macro_map_loc_unwind_toward_spelling
-(const struct line_map*, source_location);
+(const line_map_macro *, source_location);
 static source_location linemap_macro_map_loc_to_exp_point
-(const struct line_map*, source_location);
+(const line_map_macro *, source_location);
 static source_location linemap_macro_loc_to_spelling_point
-(struct line_maps *, source_location, const struct line_map **);
+(struct line_maps *, source_location, const line_map_ordinary **);
 static source_location linemap_macro_loc_to_def_point (struct line_maps *,
 						       source_location,
-						       const struct line_map **);
+						       const line_map_ordinary **);
 static source_location linemap_macro_loc_to_exp_point (struct line_maps *,
 						       source_location,
-						       const struct line_map **);
+						       const line_map_ordinary **);
 
 /* Counters defined in macro.c.  */
 extern unsigned num_expanded_macros_counter;
@@ -191,7 +191,7 @@ linemap_init (struct line_maps *set,
 void
 linemap_check_files_exited (struct line_maps *set)
 {
-  const struct line_map *map;
+  const line_map_ordinary *map;
   /* Depending upon whether we are handling preprocessed input or
      not, this can be a user error or an ICE.  */
   for (map = LINEMAPS_LAST_ORDINARY_MAP (set);
@@ -227,6 +227,10 @@ new_linemap (struct line_maps *set,
       line_map_round_alloc_size_func round_alloc_size =
 	set->round_alloc_size;
 
+      size_t map_size = (macro_map_p
+			 ? sizeof (line_map_macro)
+			 : sizeof (line_map_ordinary));
+
       /* We are going to execute some dance to try to reduce the
 	 overhead of the memory allocator, in case we are using the
 	 ggc-page.c one.
@@ -237,7 +241,7 @@ new_linemap (struct line_maps *set,
 
       alloc_size =
 	(2 * LINEMAPS_ALLOCATED (set, macro_map_p) +  256)
-	* sizeof (struct line_map);
+	* map_size;
 
       /* Get the actual size of memory that is going to be allocated
 	 by the allocator.  */
@@ -248,25 +252,37 @@ new_linemap (struct line_maps *set,
 	 Let's get back to the number of macro map that amounts
 	 to.  */
       LINEMAPS_ALLOCATED (set, macro_map_p) =
-	alloc_size / (sizeof (struct line_map));
+	alloc_size / map_size;
 
       /* And now let's really do the re-allocation.  */
-      LINEMAPS_MAPS (set, macro_map_p) =
-	(struct line_map *) (*reallocator)
-	(LINEMAPS_MAPS (set, macro_map_p),
-	 (LINEMAPS_ALLOCATED (set, macro_map_p)
-	  * sizeof (struct line_map)));
-
-      result =
-	&LINEMAPS_MAPS (set, macro_map_p)[LINEMAPS_USED (set, macro_map_p)];
+      if (macro_map_p)
+	{
+	  set->info_macro.maps
+	    = (line_map_macro *) (*reallocator) (set->info_macro.maps,
+						 (LINEMAPS_ALLOCATED (set, macro_map_p)
+						  * map_size));
+	  result = &set->info_macro.maps[LINEMAPS_USED (set, macro_map_p)];
+	}
+      else
+	{
+	  set->info_ordinary.maps =
+	    (line_map_ordinary *) (*reallocator) (set->info_ordinary.maps,
+						  (LINEMAPS_ALLOCATED (set, macro_map_p)
+						   * map_size));
+	  result = &set->info_ordinary.maps[LINEMAPS_USED (set, macro_map_p)];
+	}
       memset (result, 0,
 	      ((LINEMAPS_ALLOCATED (set, macro_map_p)
 		- LINEMAPS_USED (set, macro_map_p))
-	       * sizeof (struct line_map)));
+	       * map_size));
     }
   else
-    result =
-      &LINEMAPS_MAPS (set, macro_map_p)[LINEMAPS_USED (set, macro_map_p)];
+    {
+      if (macro_map_p)
+	result = &set->info_macro.maps[LINEMAPS_USED (set, macro_map_p)];
+      else
+	result = &set->info_ordinary.maps[LINEMAPS_USED (set, macro_map_p)];
+    }
 
   LINEMAPS_USED (set, macro_map_p)++;
 
@@ -291,7 +307,6 @@ const struct line_map *
 linemap_add (struct line_maps *set, enum lc_reason reason,
 	     unsigned int sysp, const char *to_file, linenum_type to_line)
 {
-  struct line_map *map;
   source_location start_location = set->highest_location + 1;
 
   linemap_assert (!(LINEMAPS_ORDINARY_USED (set)
@@ -311,7 +326,8 @@ linemap_add (struct line_maps *set, enum lc_reason reason,
       return NULL;
     }
 
-  map = new_linemap (set, reason);
+  linemap_assert (reason != LC_ENTER_MACRO);
+  line_map_ordinary *map = linemap_check_ordinary (new_linemap (set, reason));
 
   if (to_file && *to_file == '\0' && reason != LC_RENAME_VERBATIM)
     to_file = "<stdin>";
@@ -325,7 +341,7 @@ linemap_add (struct line_maps *set, enum lc_reason reason,
 	 location inside the "includer" right after the #include
 	 "included", this variable points the map in use right before the
 	 #include "included", inside the same "includer" file.  */
-      struct line_map *from;
+      line_map_ordinary *from;
       bool error;
 
       if (MAIN_FILE_P (map - 1))
@@ -365,7 +381,6 @@ linemap_add (struct line_maps *set, enum lc_reason reason,
 	}
     }
 
-  linemap_assert (reason != LC_ENTER_MACRO);
   ORDINARY_MAP_IN_SYSTEM_HEADER_P (map) = sysp;
   MAP_START_LOCATION (map) = start_location;
   ORDINARY_MAP_FILE_NAME (map) = to_file;
@@ -429,11 +444,11 @@ linemap_tracks_macro_expansion_locs_p (struct line_maps *set)
    this function cannot encode {line,column} pairs into locations of
    macro tokens anymore.  */
 
-const struct line_map *
+const line_map_macro *
 linemap_enter_macro (struct line_maps *set, struct cpp_hashnode *macro_node,
 		     source_location expansion, unsigned int num_tokens)
 {
-  struct line_map *map;
+  line_map_macro *map;
   source_location start_location;
   /* Cast away extern "C" from the type of xrealloc.  */
   line_map_realloc reallocator = (set->reallocator
@@ -447,7 +462,7 @@ linemap_enter_macro (struct line_maps *set, struct cpp_hashnode *macro_node,
     /* We ran out of macro map space.   */
     return NULL;
 
-  map = new_linemap (set, LC_ENTER_MACRO);
+  map = linemap_check_macro (new_linemap (set, LC_ENTER_MACRO));
 
   MAP_START_LOCATION (map) = start_location;
   MACRO_MAP_MACRO (map) = macro_node;
@@ -489,7 +504,7 @@ linemap_enter_macro (struct line_maps *set, struct cpp_hashnode *macro_node,
    replaces.  */
 
 source_location
-linemap_add_macro_token (const struct line_map *map,
+linemap_add_macro_token (const line_map_macro *map,
 			 unsigned int token_no,
 			 source_location orig_loc,
 			 source_location orig_parm_replacement_loc)
@@ -516,7 +531,7 @@ source_location
 linemap_line_start (struct line_maps *set, linenum_type to_line,
 		    unsigned int max_column_hint)
 {
-  struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (set);
+  line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (set);
   source_location highest = set->highest_location;
   source_location r;
   linenum_type last_line =
@@ -559,11 +574,12 @@ linemap_line_start (struct line_maps *set, linenum_type to_line,
       if (line_delta < 0
 	  || last_line != ORDINARY_MAP_STARTING_LINE_NUMBER (map)
 	  || SOURCE_COLUMN (map, highest) >= (1U << column_bits))
-	map = (struct line_map *) linemap_add (set, LC_RENAME,
-					       ORDINARY_MAP_IN_SYSTEM_HEADER_P
-					       (map),
-					       ORDINARY_MAP_FILE_NAME (map),
-					       to_line);
+	map = linemap_check_ordinary
+	        (const_cast <line_map *>
+		  (linemap_add (set, LC_RENAME,
+				ORDINARY_MAP_IN_SYSTEM_HEADER_P (map),
+				ORDINARY_MAP_FILE_NAME (map),
+				to_line)));
       SET_ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (map, column_bits);
       r = (MAP_START_LOCATION (map)
 	   + ((to_line - ORDINARY_MAP_STARTING_LINE_NUMBER (map))
@@ -607,7 +623,7 @@ linemap_position_for_column (struct line_maps *set, unsigned int to_column)
 	}
       else
 	{
-	  struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (set);
+	  line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (set);
 	  r = linemap_line_start (set, SOURCE_LINE (map, r), to_column + 50);
 	}
     }
@@ -621,16 +637,16 @@ linemap_position_for_column (struct line_maps *set, unsigned int to_column)
    column.  */
 
 source_location
-linemap_position_for_line_and_column (const struct line_map *map,
+linemap_position_for_line_and_column (const line_map_ordinary *ord_map,
 				      linenum_type line,
 				      unsigned column)
 {
-  linemap_assert (ORDINARY_MAP_STARTING_LINE_NUMBER (map) <= line);
+  linemap_assert (ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map) <= line);
 
-  return (MAP_START_LOCATION (map)
-	  + ((line - ORDINARY_MAP_STARTING_LINE_NUMBER (map))
-	     << ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (map))
-	  + (column & ((1 << ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (map)) - 1)));
+  return (MAP_START_LOCATION (ord_map)
+	  + ((line - ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map))
+	     << ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (ord_map))
+	  + (column & ((1 << ORDINARY_MAP_NUMBER_OF_COLUMN_BITS (ord_map)) - 1)));
 }
 
 /* Encode and return a source_location starting from location LOC and
@@ -642,7 +658,7 @@ linemap_position_for_loc_and_offset (struct line_maps *set,
 				     source_location loc,
 				     unsigned int offset)
 {
-  const struct line_map * map = NULL;
+  const line_map_ordinary * map = NULL;
 
   /* This function does not support virtual locations yet.  */
   if (linemap_assert_fails
@@ -671,7 +687,8 @@ linemap_position_for_loc_and_offset (struct line_maps *set,
       return loc;
 
   offset += SOURCE_COLUMN (map, loc);
-  if (linemap_assert_fails (offset < (1u << map->d.ordinary.column_bits)))
+  if (linemap_assert_fails
+        (offset < (1u << map->column_bits)))
     return loc;
 
   source_location r = 
@@ -703,11 +720,11 @@ linemap_lookup (struct line_maps *set, source_location line)
    monotonic increasing, and so the list is sorted and we can use a
    binary search.  */
 
-static const struct line_map *
+static const line_map_ordinary *
 linemap_ordinary_map_lookup (struct line_maps *set, source_location line)
 {
   unsigned int md, mn, mx;
-  const struct line_map *cached, *result;
+  const line_map_ordinary *cached, *result;
 
   if (IS_ADHOC_LOC (line))
     line = set->location_adhoc_data_map.data[line & MAX_SOURCE_LOCATION].locus;
@@ -751,11 +768,11 @@ linemap_ordinary_map_lookup (struct line_maps *set, source_location line)
    monotonic decreasing, and so the list is sorted and we can use a
    binary search.  */
 
-static const struct line_map*
+static const line_map_macro *
 linemap_macro_map_lookup (struct line_maps *set, source_location line)
 {
   unsigned int md, mn, mx;
-  const struct line_map *cached, *result;
+  const struct line_map_macro *cached, *result;
 
   if (IS_ADHOC_LOC (line))
     line = set->location_adhoc_data_map.data[line & MAX_SOURCE_LOCATION].locus;
@@ -811,7 +828,7 @@ linemap_macro_expansion_map_p (const struct line_map *map)
    line-map.h to understand what a macro expansion point is.  */
 
 static source_location
-linemap_macro_map_loc_to_exp_point (const struct line_map *map,
+linemap_macro_map_loc_to_exp_point (const line_map_macro *map,
 				    source_location location ATTRIBUTE_UNUSED)
 {
   linemap_assert (linemap_macro_expansion_map_p (map)
@@ -831,7 +848,7 @@ linemap_macro_map_loc_to_exp_point (const struct line_map *map,
    macro.  */
 
 static source_location
-linemap_macro_map_loc_to_def_point (const struct line_map *map,
+linemap_macro_map_loc_to_def_point (const line_map_macro *map,
 				    source_location location)
 {
   unsigned token_no;
@@ -855,7 +872,7 @@ linemap_macro_map_loc_to_def_point (const struct line_map *map,
    In other words, this returns the xI location presented in the
    comments of line_map_macro above.  */
 source_location
-linemap_macro_map_loc_unwind_toward_spelling (const struct line_map* map,
+linemap_macro_map_loc_unwind_toward_spelling (const line_map_macro* map,
 					      source_location location)
 {
   unsigned token_no;
@@ -882,7 +899,7 @@ int
 linemap_get_expansion_line (struct line_maps *set,
 			    source_location location)
 {
-  const struct line_map *map = NULL;
+  const line_map_ordinary *map = NULL;
 
   if (IS_ADHOC_LOC (location))
     location = set->location_adhoc_data_map.data[location
@@ -910,7 +927,7 @@ const char*
 linemap_get_expansion_filename (struct line_maps *set,
 				source_location location)
 {
-  const struct line_map *map = NULL;
+  const struct line_map_ordinary *map = NULL;
 
   if (IS_ADHOC_LOC (location))
     location = set->location_adhoc_data_map.data[location
@@ -928,7 +945,7 @@ linemap_get_expansion_filename (struct line_maps *set,
 /* Return the name of the macro associated to MACRO_MAP.  */
 
 const char*
-linemap_map_get_macro_name (const struct line_map* macro_map)
+linemap_map_get_macro_name (const line_map_macro *macro_map)
 {
   linemap_assert (macro_map && linemap_macro_expansion_map_p (macro_map));
   return (const char*) NODE_NAME (MACRO_MAP_MACRO (macro_map));
@@ -965,16 +982,18 @@ linemap_location_in_system_header_p (struct line_maps *set,
 	{
 	  if (!linemap_macro_expansion_map_p (map))
 	    /* It's a normal token.  */
-	    return LINEMAP_SYSP (map);
+	    return LINEMAP_SYSP (linemap_check_ordinary (map));
 	  else
 	    {
+	      const line_map_macro *macro_map = linemap_check_macro (map);
+
 	      /* It's a token resulting from a macro expansion.  */
 	      source_location loc =
-		linemap_macro_map_loc_unwind_toward_spelling (map, location);
+		linemap_macro_map_loc_unwind_toward_spelling (macro_map, location);
 	      if (loc < RESERVED_LOCATION_COUNT)
 		/* This token might come from a built-in macro.  Let's
 		   look at where that macro got expanded.  */
-		location = linemap_macro_map_loc_to_exp_point (map, location);
+		location = linemap_macro_map_loc_to_exp_point (macro_map, location);
 	      else
 		location = loc;
 	    }
@@ -1025,12 +1044,14 @@ first_map_in_common_1 (struct line_maps *set,
     {
       if (MAP_START_LOCATION (map0) < MAP_START_LOCATION (map1))
 	{
-	  l0 = linemap_macro_map_loc_to_exp_point (map0, l0);
+	  l0 = linemap_macro_map_loc_to_exp_point (linemap_check_macro (map0),
+						   l0);
 	  map0 = linemap_lookup (set, l0);
 	}
       else
 	{
-	  l1 = linemap_macro_map_loc_to_exp_point (map1, l1);
+	  l1 = linemap_macro_map_loc_to_exp_point (linemap_check_macro (map1),
+						   l1);
 	  map1 = linemap_lookup (set, l1);
 	}
     }
@@ -1120,7 +1141,7 @@ linemap_compare_locations (struct line_maps *set,
 /* Print an include trace, for e.g. the -H option of the preprocessor.  */
 
 static void
-trace_include (const struct line_maps *set, const struct line_map *map)
+trace_include (const struct line_maps *set, const line_map_ordinary *map)
 {
   unsigned int i = set->depth;
 
@@ -1138,7 +1159,7 @@ trace_include (const struct line_maps *set, const struct line_map *map)
 static source_location
 linemap_macro_loc_to_spelling_point (struct line_maps *set,
 				     source_location location,
-				     const struct line_map **original_map)
+				     const line_map_ordinary **original_map)
 {
   struct line_map *map;
 
@@ -1150,16 +1171,18 @@ linemap_macro_loc_to_spelling_point (struct line_maps *set,
 
   while (true)
     {
-      map = (struct line_map*) linemap_lookup (set, location);
+      map = const_cast <line_map *> (linemap_lookup (set, location));
       if (!linemap_macro_expansion_map_p (map))
 	break;
 
-      location =
-	linemap_macro_map_loc_unwind_toward_spelling (map, location);
+      location
+	= linemap_macro_map_loc_unwind_toward_spelling
+	    (linemap_check_macro (map),
+	     location);
     }
 
   if (original_map)
-    *original_map = map;
+    *original_map = linemap_check_ordinary (map);
   return location;
 }
 
@@ -1176,7 +1199,7 @@ linemap_macro_loc_to_spelling_point (struct line_maps *set,
 static source_location
 linemap_macro_loc_to_def_point (struct line_maps *set,
 				source_location location,
-				const struct line_map **original_map)
+				const line_map_ordinary **original_map)
 {
   struct line_map *map;
 
@@ -1188,16 +1211,17 @@ linemap_macro_loc_to_def_point (struct line_maps *set,
 
   while (true)
     {
-      map = (struct line_map*) linemap_lookup (set, location);
+      map = const_cast <line_map *> (linemap_lookup (set, location));
       if (!linemap_macro_expansion_map_p (map))
 	break;
 
       location =
-	linemap_macro_map_loc_to_def_point (map, location);
+	linemap_macro_map_loc_to_def_point (linemap_check_macro (map),
+					    location);
     }
 
   if (original_map)
-    *original_map = map;
+    *original_map = linemap_check_ordinary (map);
   return location;
 }
 
@@ -1218,7 +1242,7 @@ linemap_macro_loc_to_def_point (struct line_maps *set,
 static source_location
 linemap_macro_loc_to_exp_point (struct line_maps *set,
 				source_location location,
-				const struct line_map **original_map)
+				const line_map_ordinary **original_map)
 {
   struct line_map *map;
 
@@ -1230,14 +1254,15 @@ linemap_macro_loc_to_exp_point (struct line_maps *set,
 
   while (true)
     {
-      map = (struct line_map*) linemap_lookup (set, location);
+      map = const_cast <line_map *> (linemap_lookup (set, location));
       if (!linemap_macro_expansion_map_p (map))
 	break;
-      location = linemap_macro_map_loc_to_exp_point (map, location);
+      location = linemap_macro_map_loc_to_exp_point (linemap_check_macro (map),
+						     location);
     }
 
   if (original_map)
-    *original_map = map;
+    *original_map = linemap_check_ordinary (map);
   return location;
 }
 
@@ -1293,7 +1318,7 @@ source_location
 linemap_resolve_location (struct line_maps *set,
 			  source_location loc,
 			  enum location_resolution_kind lrk,
-			  const struct line_map **map)
+			  const line_map_ordinary **map)
 {
   if (IS_ADHOC_LOC (loc))
     loc = set->location_adhoc_data_map.data[loc & MAX_SOURCE_LOCATION].locus;
@@ -1343,18 +1368,19 @@ linemap_unwind_toward_expansion (struct line_maps *set,
 				 const struct line_map **map)
 {
   source_location resolved_location;
+  const line_map_macro *macro_map = linemap_check_macro (*map);
   const struct line_map *resolved_map;
 
   if (IS_ADHOC_LOC (loc))
     loc = set->location_adhoc_data_map.data[loc & MAX_SOURCE_LOCATION].locus;
 
   resolved_location =
-    linemap_macro_map_loc_unwind_toward_spelling (*map, loc);
+    linemap_macro_map_loc_unwind_toward_spelling (macro_map, loc);
   resolved_map = linemap_lookup (set, resolved_location);
 
   if (!linemap_macro_expansion_map_p (resolved_map))
     {
-      resolved_location = linemap_macro_map_loc_to_exp_point (*map, loc);
+      resolved_location = linemap_macro_map_loc_to_exp_point (macro_map, loc);
       resolved_map = linemap_lookup (set, resolved_location);
     }
 
@@ -1382,7 +1408,8 @@ linemap_unwind_to_first_non_reserved_loc (struct line_maps *set,
 					  const struct line_map **map)
 {
   source_location resolved_loc;
-  const struct line_map *map0 = NULL, *map1 = NULL;
+  const struct line_map *map0 = NULL;
+  const line_map_ordinary *map1 = NULL;
 
   if (IS_ADHOC_LOC (loc))
     loc = set->location_adhoc_data_map.data[loc & MAX_SOURCE_LOCATION].locus;
@@ -1453,10 +1480,12 @@ linemap_expand_location (struct line_maps *set,
       if (linemap_location_from_macro_expansion_p (set, loc))
 	abort ();
 
-      xloc.file = LINEMAP_FILE (map);
-      xloc.line = SOURCE_LINE (map, loc);
-      xloc.column = SOURCE_COLUMN (map, loc);
-      xloc.sysp = LINEMAP_SYSP (map) != 0;
+      const line_map_ordinary *ord_map = linemap_check_ordinary (map);
+
+      xloc.file = LINEMAP_FILE (ord_map);
+      xloc.line = SOURCE_LINE (ord_map, loc);
+      xloc.column = SOURCE_COLUMN (ord_map, loc);
+      xloc.sysp = LINEMAP_SYSP (ord_map) != 0;
     }
 
   return xloc;
@@ -1474,7 +1503,7 @@ linemap_dump (FILE *stream, struct line_maps *set, unsigned ix, bool is_macro)
       = { "LC_ENTER", "LC_LEAVE", "LC_RENAME", "LC_RENAME_VERBATIM",
 	  "LC_ENTER_MACRO" };
   const char *reason;
-  struct line_map *map;
+  const line_map *map;
 
   if (stream == NULL)
     stream = stderr;
@@ -1488,26 +1517,32 @@ linemap_dump (FILE *stream, struct line_maps *set, unsigned ix, bool is_macro)
 
   fprintf (stream, "Map #%u [%p] - LOC: %u - REASON: %s - SYSP: %s\n",
 	   ix, (void *) map, map->start_location, reason,
-	   (!is_macro && ORDINARY_MAP_IN_SYSTEM_HEADER_P (map)) ? "yes" : "no");
+	   ((!is_macro
+	     && ORDINARY_MAP_IN_SYSTEM_HEADER_P (linemap_check_ordinary (map)))
+	    ? "yes" : "no"));
   if (!is_macro)
     {
+      const line_map_ordinary *ord_map = linemap_check_ordinary (map);
       unsigned includer_ix;
-      struct line_map *includer_map;
+      const line_map_ordinary *includer_map;
 
-      includer_ix = ORDINARY_MAP_INCLUDER_FILE_INDEX (map);
+      includer_ix = ORDINARY_MAP_INCLUDER_FILE_INDEX (ord_map);
       includer_map = includer_ix < LINEMAPS_ORDINARY_USED (set)
 		     ? LINEMAPS_ORDINARY_MAP_AT (set, includer_ix)
 		     : NULL;
 
-      fprintf (stream, "File: %s:%d\n", ORDINARY_MAP_FILE_NAME (map),
-	       ORDINARY_MAP_STARTING_LINE_NUMBER (map));
+      fprintf (stream, "File: %s:%d\n", ORDINARY_MAP_FILE_NAME (ord_map),
+	       ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map));
       fprintf (stream, "Included from: [%d] %s\n", includer_ix,
 	       includer_map ? ORDINARY_MAP_FILE_NAME (includer_map) : "None");
     }
   else
-    fprintf (stream, "Macro: %s (%u tokens)\n",
-	     linemap_map_get_macro_name (map),
-	     MACRO_MAP_NUM_MACRO_TOKENS (map));
+    {
+      const line_map_macro *macro_map = linemap_check_macro (map);
+      fprintf (stream, "Macro: %s (%u tokens)\n",
+	       linemap_map_get_macro_name (macro_map),
+	       MACRO_MAP_NUM_MACRO_TOKENS (macro_map));
+    }
 
   fprintf (stream, "\n");
 }
@@ -1521,7 +1556,7 @@ linemap_dump_location (struct line_maps *set,
 		       source_location loc,
 		       FILE *stream)
 {
-  const struct line_map *map;
+  const line_map_ordinary *map;
   source_location location;
   const char *path = "", *from = "";
   int l = -1, c = -1, s = -1, e = -1;
@@ -1578,7 +1613,7 @@ linemap_get_file_highest_location (struct line_maps *set,
   int i;
   for (i = set->info_ordinary.used - 1; i >= 0; --i)
     {
-      const char *fname = set->info_ordinary.maps[i].d.ordinary.to_file;
+      const char *fname = set->info_ordinary.maps[i].to_file;
       if (fname && !filename_cmp (fname, file_name))
 	break;
     }
@@ -1610,16 +1645,16 @@ linemap_get_statistics (struct line_maps *set,
     macro_maps_allocated_size, macro_maps_used_size,
     macro_maps_locations_size = 0, duplicated_macro_maps_locations_size = 0;
 
-  struct line_map *cur_map;
+  const line_map_macro *cur_map;
 
   ordinary_maps_allocated_size =
-    LINEMAPS_ORDINARY_ALLOCATED (set) * sizeof (struct line_map);
+    LINEMAPS_ORDINARY_ALLOCATED (set) * sizeof (struct line_map_ordinary);
 
   ordinary_maps_used_size =
-    LINEMAPS_ORDINARY_USED (set) * sizeof (struct line_map);
+    LINEMAPS_ORDINARY_USED (set) * sizeof (struct line_map_ordinary);
 
   macro_maps_allocated_size =
-    LINEMAPS_MACRO_ALLOCATED (set) * sizeof (struct line_map);
+    LINEMAPS_MACRO_ALLOCATED (set) * sizeof (struct line_map_macro);
 
   for (cur_map = LINEMAPS_MACRO_MAPS (set);
        cur_map && cur_map <= LINEMAPS_LAST_MACRO_MAP (set);
@@ -1642,7 +1677,7 @@ linemap_get_statistics (struct line_maps *set,
     }
 
   macro_maps_used_size =
-    LINEMAPS_MACRO_USED (set) * sizeof (struct line_map);
+    LINEMAPS_MACRO_USED (set) * sizeof (struct line_map_macro);
 
   s->num_ordinary_maps_allocated = LINEMAPS_ORDINARY_ALLOCATED (set);
   s->num_ordinary_maps_used = LINEMAPS_ORDINARY_USED (set);
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 1e0a0b560ba..f76e10b0b2e 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -141,7 +141,7 @@ static inline const cpp_token **tokens_buff_put_token_to (const cpp_token **,
                                                           const cpp_token *,
                                                           source_location,
                                                           source_location,
-                                                          const struct line_map *,
+                                                          const line_map_macro *,
                                                           unsigned int);
 
 static const cpp_token **tokens_buff_add_token (_cpp_buff *,
@@ -149,7 +149,7 @@ static const cpp_token **tokens_buff_add_token (_cpp_buff *,
 						const cpp_token *,
 						source_location,
 						source_location,
-						const struct line_map *,
+						const line_map_macro *,
 						unsigned int);
 static inline void tokens_buff_remove_last_token (_cpp_buff *);
 static void replace_args (cpp_reader *, cpp_hashnode *, cpp_macro *,
@@ -195,7 +195,9 @@ _cpp_warn_if_unused_macro (cpp_reader *pfile, cpp_hashnode *node,
       cpp_macro *macro = node->value.macro;
 
       if (!macro->used
-	  && MAIN_FILE_P (linemap_lookup (pfile->line_table, macro->line)))
+	  && MAIN_FILE_P (linemap_check_ordinary
+			    (linemap_lookup (pfile->line_table,
+					     macro->line))))
 	cpp_warning_with_line (pfile, CPP_W_UNUSED_MACROS, macro->line, 0,
 			       "macro \"%s\" is not used", NODE_NAME (node));
     }
@@ -453,7 +455,7 @@ builtin_macro (cpp_reader *pfile, cpp_hashnode *node, source_location loc)
 	 macro.  */
       source_location *virt_locs = NULL;
       _cpp_buff *token_buf = tokens_buff_new (pfile, 1, &virt_locs);
-      const line_map * map =
+      const line_map_macro * map =
 	linemap_enter_macro (pfile->line_table, node,
 					    token->src_loc, 1);
       tokens_buff_add_token (token_buf, virt_locs, token,
@@ -1167,7 +1169,7 @@ enter_macro_context (cpp_reader *pfile, cpp_hashnode *node,
 	    {
 	      unsigned int i;
 	      const cpp_token *src = macro->exp.tokens;
-	      const struct line_map *map;
+	      const line_map_macro *map;
 	      source_location *virt_locs = NULL;
 	      _cpp_buff *macro_tokens
 		= tokens_buff_new (pfile, tokens_count, &virt_locs);
@@ -1535,7 +1537,7 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
   _cpp_buff *buff = NULL;
   source_location *virt_locs = NULL;
   unsigned int exp_count;
-  const struct line_map *map = NULL;
+  const line_map_macro *map = NULL;
   int track_macro_exp;
 
   /* First, fully macro-expand arguments, calculating the number of
@@ -2066,7 +2068,7 @@ tokens_buff_put_token_to (const cpp_token **dest,
 			  const cpp_token *token,
 			  source_location virt_loc,
 			  source_location parm_def_loc,			  
-			  const struct line_map *map,
+			  const line_map_macro *map,
 			  unsigned int macro_token_index)
 {
   source_location macro_loc = virt_loc;
@@ -2111,7 +2113,7 @@ tokens_buff_add_token (_cpp_buff *buffer,
 		       const cpp_token *token,
 		       source_location virt_loc,
 		       source_location parm_def_loc,
-		       const struct line_map *map,
+		       const line_map_macro *map,
 		       unsigned int macro_token_index)
 {
   const cpp_token **result;