re PR c/81364 (Bogus -Wmultistatement-macros warning)

	PR c/81364
	* c-parser.c (c_parser_else_body): Don't warn about multistatement
	macro expansion if the body is in { }.
	(c_parser_while_statement): Likewise.
	(c_parser_for_statement): Likewise.

	* Wmultistatement-macros-12.c: New test.

From-SVN: r250498

gcc/c/ChangeLog

+2017-07-25  Marek Polacek  <polacek@redhat.com>
+
+	PR c/81364
+	* c-parser.c (c_parser_else_body): Don't warn about multistatement
+	macro expansion if the body is in { }.
+	(c_parser_while_statement): Likewise.
+	(c_parser_for_statement): Likewise.
+
 2017-07-18  Nathan Sidwell  <nathan@acm.org>
 
 	* c-parser.c (c_parser_array_notation): Use TYPE_{MIN,MAX}_VALUE.

gcc/c/c-parser.c

@@ -5557,7 +5557,8 @@ c_parser_else_body (c_parser *parser, const token_indent_info &else_tinfo,
     }
   else
     {
-      body_loc_after_labels = c_parser_peek_token (parser)->location;
+      if (!c_parser_next_token_is (parser, CPP_OPEN_BRACE))
+	body_loc_after_labels = c_parser_peek_token (parser)->location;
       c_parser_statement_after_labels (parser, NULL, chain);
     }
 
@@ -5811,6 +5812,7 @@ c_parser_while_statement (c_parser *parser, bool ivdep, bool *if_p)
     = get_token_indent_info (c_parser_peek_token (parser));
 
   location_t loc_after_labels;
+  bool open_brace = c_parser_next_token_is (parser, CPP_OPEN_BRACE);
   body = c_parser_c99_block_statement (parser, if_p, &loc_after_labels);
   c_finish_loop (loc, cond, NULL, body, c_break_label, c_cont_label, true);
   add_stmt (c_end_compound_stmt (loc, block, flag_isoc99));
@@ -5820,7 +5822,7 @@ c_parser_while_statement (c_parser *parser, bool ivdep, bool *if_p)
     = get_token_indent_info (c_parser_peek_token (parser));
   warn_for_misleading_indentation (while_tinfo, body_tinfo, next_tinfo);
 
-  if (next_tinfo.type != CPP_SEMICOLON)
+  if (next_tinfo.type != CPP_SEMICOLON && !open_brace)
     warn_for_multistatement_macros (loc_after_labels, next_tinfo.location,
 				    while_tinfo.location, RID_WHILE);
 
@@ -6109,6 +6111,7 @@ c_parser_for_statement (c_parser *parser, bool ivdep, bool *if_p)
     = get_token_indent_info (c_parser_peek_token (parser));
 
   location_t loc_after_labels;
+  bool open_brace = c_parser_next_token_is (parser, CPP_OPEN_BRACE);
   body = c_parser_c99_block_statement (parser, if_p, &loc_after_labels);
 
   if (is_foreach_statement)
@@ -6122,7 +6125,7 @@ c_parser_for_statement (c_parser *parser, bool ivdep, bool *if_p)
     = get_token_indent_info (c_parser_peek_token (parser));
   warn_for_misleading_indentation (for_tinfo, body_tinfo, next_tinfo);
 
-  if (next_tinfo.type != CPP_SEMICOLON)
+  if (next_tinfo.type != CPP_SEMICOLON && !open_brace)
     warn_for_multistatement_macros (loc_after_labels, next_tinfo.location,
 				    for_tinfo.location, RID_FOR);
 

gcc/testsuite/ChangeLog

+2017-07-25  Marek Polacek  <polacek@redhat.com>
+
+	PR c/81364
+	* Wmultistatement-macros-12.c: New test.
+
 2017-07-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR target/81414

gcc/testsuite/c-c++-common/Wmultistatement-macros-12.c

+/* PR c/81364 */
+/* { dg-do compile } */
+/* { dg-options "-Wmultistatement-macros" } */
+
+#define FOO0 if (1) { } else
+#define TST0 \
+void bar0 (void) \
+{ \
+  FOO0 { } /* { dg-bogus "macro expands to multiple statements" } */ \
+}
+TST0
+
+#define FOO1 for (;;)
+#define TST1 \
+void bar1 (void) \
+{ \
+  FOO1 { } /* { dg-bogus "macro expands to multiple statements" } */ \
+}
+TST1
+
+#define FOO2 while (1)
+#define TST2 \
+void bar2 (void) \
+{ \
+  FOO2 { } /* { dg-bogus "macro expands to multiple statements" } */ \
+}
+TST2
+
+#define FOO3 switch (1)
+#define TST3 \
+void bar3 (void) \
+{ \
+  FOO3 { } /* { dg-bogus "macro expands to multiple statements" } */ \
+}
+TST3
+
+#define FOO4 if (1)
+#define TST4 \
+void bar4 (void) \
+{ \
+  FOO4 { } /* { dg-bogus "macro expands to multiple statements" } */ \
+}
+TST4