Implement -Wmisleading-indentation

gcc/ChangeLog:
	* doc/invoke.texi (Warning Options): Add -Wmisleading-indentation.
	(-Wmisleading-indentation): New option.
	* Makefile.in (C_COMMON_OBJS): Add c-family/c-indentation.o.

gcc/c-family/ChangeLog:
	* c-common.h (warn_for_misleading_indentation): New prototype.
	* c-indentation.c: New file.
	* c.opt (Wmisleading-indentation): New option.

gcc/c/ChangeLog:
	* c-parser.c (c_parser_if_body): Add param "if_loc", use it
	to add a call to warn_for_misleading_indentation.
	(c_parser_else_body): Likewise, adding param "else_loc".
	(c_parser_if_statement): Check for misleading indentation.
	(c_parser_while_statement): Likewise.
	(c_parser_for_statement): Likewise.

gcc/cp/ChangeLog:
	* parser.c (cp_parser_selection_statement): Add location and
	guard_kind arguments to calls to
	cp_parser_implicitly_scoped_statement.
	(cp_parser_iteration_statement): Likewise for calls to
	cp_parser_already_scoped_statement.
	(cp_parser_implicitly_scoped_statement): Add "guard_loc" and
	"guard_kind" params; use them to warn for misleading
	indentation.
	(cp_parser_already_scoped_statement): Likewise.

gcc/testsuite/ChangeLog:
	* c-c++-common/Wmisleading-indentation.c: New testcase.
	* c-c++-common/Wmisleading-indentation-2.c: New testcase.
	* c-c++-common/Wmisleading-indentation-2.md: New file.

libcpp/ChangeLog:
	* directives.c (do_line): Set seen_line_directive on line_table.
	(do_linemarker): Likewise.
	* include/line-map.h (struct line_maps): Add new field
	"seen_line_directive".

From-SVN: r223098

3 files changed, 14 insertions, 2 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 51304424753..c0f04ac0445 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,10 @@
+2015-05-12  David Malcolm  <dmalcolm@redhat.com>
+
+	* directives.c (do_line): Set seen_line_directive on line_table.
+	(do_linemarker): Likewise.
+	* include/line-map.h (struct line_maps): Add new field
+	"seen_line_directive".
+
 2015-05-08  Jason Merrill  <jason@redhat.com>
 
 	* include/cpplib.h: Add CPP_W_CXX11_COMPAT.
diff --git a/libcpp/directives.c b/libcpp/directives.c
index 2a824e6ed3f..356ec135100 100644
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -911,7 +911,7 @@ strtolinenum (const uchar *str, size_t len, linenum_type *nump, bool *wrapped)
 static void
 do_line (cpp_reader *pfile)
 {
-  const struct line_maps *line_table = pfile->line_table;
+  struct line_maps *line_table = pfile->line_table;
   const struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
 
   /* skip_rest_of_line() may cause line table to be realloc()ed so note down
@@ -965,6 +965,7 @@ do_line (cpp_reader *pfile)
   skip_rest_of_line (pfile);
   _cpp_do_file_change (pfile, LC_RENAME_VERBATIM, new_file, new_lineno,
 		       map_sysp);
+  line_table->seen_line_directive = true;
 }
 
 /* Interpret the # 44 "file" [flags] notation, which has slightly
@@ -973,7 +974,7 @@ do_line (cpp_reader *pfile)
 static void
 do_linemarker (cpp_reader *pfile)
 {
-  const struct line_maps *line_table = pfile->line_table;
+  struct line_maps *line_table = pfile->line_table;
   const struct line_map *map = LINEMAPS_LAST_ORDINARY_MAP (line_table);
   const cpp_token *token;
   const char *new_file = ORDINARY_MAP_FILE_NAME (map);
@@ -1052,6 +1053,7 @@ do_linemarker (cpp_reader *pfile)
   pfile->line_table->highest_location--;
 
   _cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp);
+  line_table->seen_line_directive = true;
 }
 
 /* Arrange the file_change callback.  pfile->line has changed to
diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
index e1681ea591d..ddeaf0c1954 100644
--- a/libcpp/include/line-map.h
+++ b/libcpp/include/line-map.h
@@ -386,6 +386,9 @@ struct GTY(()) line_maps {
   /* The special location value that is used as spelling location for
      built-in tokens.  */
   source_location builtin_location;
+
+  /* True if we've seen a #line or # 44 "file" directive.  */
+  bool seen_line_directive;
 };
 
 /* Returns the pointer to the memory region where information about