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 baffbb13d6c69e738e81fb7a4426a20cbcd636b9..6e9ed0bb17efdfc7f7755127fd9a59baff28244c 100644 (file)
--- 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 322cf98eb02b669bd636396097048133db94bd65..67dce9e125a5d94f665b363cfb1069a6f438cbfd 100644 (file)
--- 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 494f0aded36482e7acc577c6777a862dbe07bbfa..1af702a38f04c13b59391da6939978cdea41372f 100644 (file)
--- 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 (file)
index 0000000..7df74dc
--- /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;
+};