From 65791f426fc950b0af4e6e2ef675c213e623b16f Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 1 Dec 2017 09:17:06 +0100
Subject: re PR c/79153 (-Wimplicit-fallthrough missed warning)

	PR c/79153
	* tree.h (SWITCH_BREAK_LABEL_P): Define.
	* gimplify.c (collect_fallthrough_labels): Handle GIMPLE_BIND
	starting with a GIMPLE_SWITCH and ending with GIMPLE_LABEL with
	SWITCH_BREAK_LABEL_P set on the label.
	(gimplify_switch_expr): Set SWITCH_BREAK_LABEL_P on the label
	added for default case if it was missing and not all cases covered.
	Wrap GIMPLE_SWITCH and the switch_body_seq into a GIMPLE_BIND if
	switch_body_seq ends with a GIMPLE_LABEL with SWITCH_BREAK_LABEL_P
	set on the label.
	* tree-chrec.c (evolution_function_is_univariate_p): Add return true;
	to avoid -Wimplicit-fallthrough warning.
	* config/i386/i386.c (ix86_expand_special_args_builtin): Add
	FALLTHRU comment to avoid -Wimplicit-fallthrough warning.
c/
	* c-parser.c: Include tree-iterator.h.
	(c_parser_switch_statement): Emit LABEL_EXPR for the break label
	into SWITCH_BODY instead of after it and set SWITCH_BREAK_LABEL_P
	on it.
cp/
	* cp-gimplify.c (genericize_switch_stmt): Emit LABEL_EXPR for the
	break label into SWITCH_BODY instead of after it and set
	SWITCH_BREAK_LABEL_P on it.
	* parser.c (cp_parser_objc_expression): Add FALLTHRU comment to avoid
	-Wimplicit-fallthrough warning.
fortran/
	* match.c (gfc_match): Add FALLTHRU comment to avoid
	-Wimplicit-fallthrough warning.
testsuite/
	* c-c++-common/Wimplicit-fallthrough-7.c: Adjust expected warning
	line.
	* c-c++-common/Wimplicit-fallthrough-36.c: New test.

From-SVN: r255298
---
 gcc/c/ChangeLog  | 6 ++++++
 gcc/c/c-parser.c | 6 ++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

(limited to 'gcc/c')

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 90db38a..1fb0c3d 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,5 +1,11 @@
 2017-12-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c/79153
+	* c-parser.c: Include tree-iterator.h.
+	(c_parser_switch_statement): Emit LABEL_EXPR for the break label
+	into SWITCH_BODY instead of after it and set SWITCH_BREAK_LABEL_P
+	on it.
+
 	PR c/83222
 	* c-tree.h (decl_constant_value_1): Declare.
 	* c-typeck.c (decl_constant_value_1): New function.
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 755cd2b..e9267fe 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -67,6 +67,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "run-rtl-passes.h"
 #include "intl.h"
 #include "c-family/name-hint.h"
+#include "tree-iterator.h"
 
 /* We need to walk over decls with incomplete struct/union/enum types
    after parsing the whole translation unit.
@@ -5846,14 +5847,15 @@ c_parser_switch_statement (c_parser *parser, bool *if_p)
   if (!open_brace_p && c_parser_peek_token (parser)->type != CPP_SEMICOLON)
     warn_for_multistatement_macros (loc_after_labels, next_loc, switch_loc,
 				    RID_SWITCH);
-  c_finish_case (body, ce.original_type);
   if (c_break_label)
     {
       location_t here = c_parser_peek_token (parser)->location;
       tree t = build1 (LABEL_EXPR, void_type_node, c_break_label);
       SET_EXPR_LOCATION (t, here);
-      add_stmt (t);
+      SWITCH_BREAK_LABEL_P (c_break_label) = 1;
+      append_to_statement_list_force (t, &body);
     }
+  c_finish_case (body, ce.original_type);
   c_break_label = save_break;
   add_stmt (c_end_compound_stmt (switch_loc, block, flag_isoc99));
   c_parser_maybe_reclassify_token (parser);
-- 
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