From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 28 Jun 2019 22:57:16 +0000 (+0200)
Subject: backport: re PR c++/91024 (-Wimplicit-fallthrough is confused by likely/unlikely... 
X-Git-Tag: releases/gcc-9.2.0~189
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0a4024807aacfeac22da3ec21620ece3a029bfbc;p=thirdparty%2Fgcc.git

backport: re PR c++/91024 (-Wimplicit-fallthrough is confused by likely/unlikely attributes)

	Backported from mainline
	2019-06-27  Jakub Jelinek  <jakub@redhat.com>

	PR c++/91024
	* gimplify.c (collect_fallthrough_labels): Ignore GIMPLE_PREDICT
	statements.

	* g++.dg/warn/Wimplicit-fallthrough-4.C: New test.

From-SVN: r272804
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c5a7c2eb316f..025aa5b5bf0c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,12 @@
 2019-06-29  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-06-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91024
+	* gimplify.c (collect_fallthrough_labels): Ignore GIMPLE_PREDICT
+	statements.
+
 	2019-06-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/90991
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 72f1cc38ff7e..362877cbae64 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -2081,6 +2081,8 @@ collect_fallthrough_labels (gimple_stmt_iterator *gsi_p,
 	}
       else if (gimple_call_internal_p (gsi_stmt (*gsi_p), IFN_ASAN_MARK))
 	;
+      else if (gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_PREDICT)
+	;
       else if (!is_gimple_debug (gsi_stmt (*gsi_p)))
 	prev = gsi_stmt (*gsi_p);
       gsi_next (gsi_p);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b65008ba889e..1a546d3b7c1d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2019-06-29  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-06-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91024
+	* g++.dg/warn/Wimplicit-fallthrough-4.C: New test.
+
 	2019-06-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/90991
diff --git a/gcc/testsuite/g++.dg/warn/Wimplicit-fallthrough-4.C b/gcc/testsuite/g++.dg/warn/Wimplicit-fallthrough-4.C
new file mode 100644
index 000000000000..993e695fa168
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wimplicit-fallthrough-4.C
@@ -0,0 +1,22 @@
+// PR c++/91024
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wimplicit-fallthrough" }
+
+int
+foo (char c)
+{
+  int result = 0;
+
+  switch (c)
+    {
+    case 'O':
+    case 'K':
+      return result;
+    [[unlikely]] case 'X':	// { dg-bogus "this statement may fall through" }
+    case 'x':			// { dg-bogus "here" }
+      return result;
+    default:
+      break;
+    }
+  return result;
+}