re PR c++/90383 (GCC generates invalid constexpr copy/move assignment operators for types with trailing padding. (Again))

	PR c++/90383
	* tree-inline.h (struct copy_body_data): Add do_not_fold member.
	* tree-inline.c (remap_gimple_op_r): Avoid folding expressions if
	id->do_not_fold.
	(copy_tree_body_r): Likewise.
	(copy_fn): Set id.do_not_fold to true.

	* g++.dg/cpp1y/constexpr-90383-1.C: New test.
	* g++.dg/cpp1y/constexpr-90383-2.C: New test.

From-SVN: r271058

6 files changed, 62 insertions, 5 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5e30430..d1b9123 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2019-05-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90383
+	* tree-inline.h (struct copy_body_data): Add do_not_fold member.
+	* tree-inline.c (remap_gimple_op_r): Avoid folding expressions if
+	id->do_not_fold.
+	(copy_tree_body_r): Likewise.
+	(copy_fn): Set id.do_not_fold to true.
+
 2019-05-10  Martin Liska  <mliska@suse.cz>
 
 	* config/i386/i386-expand.c (ix86_expand_floorceildf_32):
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 889c08d..0ca0b5a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2019-05-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90383
+	* g++.dg/cpp1y/constexpr-90383-1.C: New test.
+	* g++.dg/cpp1y/constexpr-90383-2.C: New test.
+
 2019-05-10  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/90093
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-1.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-1.C
new file mode 100644
index 0000000..b398331
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-1.C
@@ -0,0 +1,15 @@
+// PR c++/90383
+// { dg-do compile { target c++14 } }
+
+struct alignas(8) A { constexpr A (bool x) : a(x) {} A () = delete; bool a; };
+struct B { A b; };
+
+constexpr bool
+foo ()
+{
+  B w{A (true)};
+  w.b = A (true);
+  return w.b.a;
+}
+
+static_assert (foo (), "");
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-2.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-2.C
new file mode 100644
index 0000000..a08b1dd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-90383-2.C
@@ -0,0 +1,22 @@
+// PR c++/90383
+// { dg-do run { target c++14 } }
+// { dg-options "-O2" }
+
+extern "C" void abort ();
+struct alignas(8) A { constexpr A (bool x) : a(x) {} A () = default; bool a; };
+struct B { A b; };
+
+constexpr bool
+foo ()
+{
+  B w{A (true)};
+  w.b = A (true);
+  return w.b.a;
+}
+
+int
+main ()
+{
+  if (!foo ())
+    abort ();
+}
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 2d314a7..35c005e 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1101,7 +1101,7 @@ remap_gimple_op_r (tree *tp, int *walk_subtrees, void *data)
       /* Otherwise, just copy the node.  Note that copy_tree_r already
 	 knows not to copy VAR_DECLs, etc., so this is safe.  */
 
-      if (TREE_CODE (*tp) == MEM_REF)
+      if (TREE_CODE (*tp) == MEM_REF && !id->do_not_fold)
 	{
 	  /* We need to re-canonicalize MEM_REFs from inline substitutions
 	     that can happen when a pointer argument is an ADDR_EXPR.
@@ -1327,11 +1327,11 @@ copy_tree_body_r (tree *tp, int *walk_subtrees, void *data)
 	      tree type = TREE_TYPE (*tp);
 	      tree ptr = id->do_not_unshare ? *n : unshare_expr (*n);
 	      tree old = *tp;
-	      *tp = gimple_fold_indirect_ref (ptr);
+	      *tp = id->do_not_fold ? NULL : gimple_fold_indirect_ref (ptr);
 	      if (! *tp)
 	        {
 		  type = remap_type (type, id);
-		  if (TREE_CODE (ptr) == ADDR_EXPR)
+		  if (TREE_CODE (ptr) == ADDR_EXPR && !id->do_not_fold)
 		    {
 		      *tp
 		        = fold_indirect_ref_1 (EXPR_LOCATION (ptr), type, ptr);
@@ -1360,7 +1360,7 @@ copy_tree_body_r (tree *tp, int *walk_subtrees, void *data)
 	      return NULL;
 	    }
 	}
-      else if (TREE_CODE (*tp) == MEM_REF)
+      else if (TREE_CODE (*tp) == MEM_REF && !id->do_not_fold)
 	{
 	  /* We need to re-canonicalize MEM_REFs from inline substitutions
 	     that can happen when a pointer argument is an ADDR_EXPR.
@@ -1432,7 +1432,8 @@ copy_tree_body_r (tree *tp, int *walk_subtrees, void *data)
 
 	  /* Handle the case where we substituted an INDIRECT_REF
 	     into the operand of the ADDR_EXPR.  */
-	  if (TREE_CODE (TREE_OPERAND (*tp, 0)) == INDIRECT_REF)
+	  if (TREE_CODE (TREE_OPERAND (*tp, 0)) == INDIRECT_REF
+	      && !id->do_not_fold)
 	    {
 	      tree t = TREE_OPERAND (TREE_OPERAND (*tp, 0), 0);
 	      if (TREE_TYPE (t) != TREE_TYPE (*tp))
@@ -6370,6 +6371,7 @@ copy_fn (tree fn, tree& parms, tree& result)
      since front-end specific mechanisms may rely on sharing.  */
   id.regimplify = false;
   id.do_not_unshare = true;
+  id.do_not_fold = true;
 
   /* We're not inside any EH region.  */
   id.eh_lp_nr = 0;
diff --git a/gcc/tree-inline.h b/gcc/tree-inline.h
index 4c954a0..3ede89e 100644
--- a/gcc/tree-inline.h
+++ b/gcc/tree-inline.h
@@ -113,6 +113,9 @@ struct copy_body_data
   /* True if trees may not be unshared.  */
   bool do_not_unshare;
 
+  /* True if trees should not be folded during the copying.  */
+  bool do_not_fold;
+
   /* True if new declarations may not be created during type remapping.  */
   bool prevent_decl_creation_for_types;