From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 21 Oct 2019 11:46:21 +0000 (+0200)
Subject: backport: re PR c++/91925 (-fpack-struct causes a decltype with template to ICE)
X-Git-Tag: releases/gcc-9.3.0~513
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2990eccb24c10780fc930884d899521b43bf62b4;p=thirdparty%2Fgcc.git

backport: re PR c++/91925 (-fpack-struct causes a decltype with template to ICE)

	Backported from mainline
	2019-10-01  Jakub Jelinek  <jakub@redhat.com>

	PR c++/91925
	* c-warn.c (check_alignment_of_packed_member): Ignore FIELD_DECLs
	with NULL DECL_FIELD_OFFSET.

	* g++.dg/conversion/packed2.C: New test.

From-SVN: r277255
---

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index baffbb13d6c6..6e9ed0bb17ef 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,6 +1,12 @@
 2019-10-21  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-10-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91925
+	* c-warn.c (check_alignment_of_packed_member): Ignore FIELD_DECLs
+	with NULL DECL_FIELD_OFFSET.
+
 	2019-09-27  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/88203
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
index 322cf98eb02b..67dce9e125a5 100644
--- a/gcc/c-family/c-warn.c
+++ b/gcc/c-family/c-warn.c
@@ -2784,6 +2784,8 @@ check_alignment_of_packed_member (tree type, tree field, bool rvalue)
   /* Check alignment of the data member.  */
   if (TREE_CODE (field) == FIELD_DECL
       && (DECL_PACKED (field) || TYPE_PACKED (TREE_TYPE (field)))
+      /* Ignore FIELDs not laid out yet.  */
+      && DECL_FIELD_OFFSET (field)
       && (!rvalue || TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE))
     {
       /* Check the expected alignment against the field alignment.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 494f0aded364..1af702a38f04 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2019-10-21  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-10-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91925
+	* g++.dg/conversion/packed2.C: New test.
+
 	2019-09-27  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/88203
diff --git a/gcc/testsuite/g++.dg/conversion/packed2.C b/gcc/testsuite/g++.dg/conversion/packed2.C
new file mode 100644
index 000000000000..7df74dc110b5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/conversion/packed2.C
@@ -0,0 +1,15 @@
+// PR c++/91925
+// { dg-do compile { target c++11 } }
+// { dg-options "-fpack-struct" }
+
+struct A {};
+int foo (A);
+struct B {
+  A a;
+  decltype (foo (a)) p;
+};
+template <typename T> T bar (T);
+class C {
+  A a;
+  decltype (bar (a)) p;
+};