From 66a366a05a39ce91597fe192e3d943efd810eb87 Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Tue, 16 Jan 2018 03:02:34 +0000
Subject: [PATCH] PR c++/83588 - struct with two flexible arrays causes an
 internal compiler error

gcc/cp/ChangeLog:

	PR c++/83588
	* class.c (find_flexarrays): Make a record of multiple flexible array
	members.

gcc/testsuite/ChangeLog:

	PR c++/83588
	* g++.dg/ext/flexary28.C: New test.

From-SVN: r256721
---
 gcc/cp/ChangeLog                     |  6 ++++
 gcc/cp/class.c                       |  7 +++--
 gcc/testsuite/ChangeLog              |  5 +++
 gcc/testsuite/g++.dg/ext/flexary28.C | 46 ++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/flexary28.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 533e2d34e43..7e437f8547b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2018-01-15  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/83588
+	* class.c (find_flexarrays): Make a record of multiple flexible array
+	members.
+
 2018-01-12  Jason Merrill  <jason@redhat.com>
 
 	PR c++/83186 - ICE with static_cast of list-initialized temporary.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 985b443ccdd..4103630231a 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -6566,14 +6566,17 @@ find_flexarrays (tree t, flexmems_t *fmem, bool base_p,
 	  /* Flexible array members have no upper bound.  */
 	  if (fmem->array)
 	    {
-	      /* Replace the zero-length array if it's been stored and
-		 reset the after pointer.  */
 	      if (TYPE_DOMAIN (TREE_TYPE (fmem->array)))
 		{
+		  /* Replace the zero-length array if it's been stored and
+		     reset the after pointer.  */
 		  fmem->after[bool (pun)] = NULL_TREE;
 		  fmem->array = fld;
 		  fmem->enclosing = pstr;
 		}
+	      else if (!fmem->after[bool (pun)])
+		/* Make a record of another flexible array member.  */
+		fmem->after[bool (pun)] = fld;
 	    }
 	  else
 	    {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2933f83c32f..b29c659ba51 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-15  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/83588
+	* g++.dg/ext/flexary28.C: New test.
+
 2018-01-15  Louis Krupp  <louis.krupp@zoho.com>
 
 	PR fortran/82257
diff --git a/gcc/testsuite/g++.dg/ext/flexary28.C b/gcc/testsuite/g++.dg/ext/flexary28.C
new file mode 100644
index 00000000000..68172c486d2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/flexary28.C
@@ -0,0 +1,46 @@
+// PR c++/83588 - struct with two flexible arrays causes an internal compiler
+// error
+// { dg-do compile }
+// { dg-options "-Wno-pedantic" }
+
+struct A {
+  int i;
+  int a[];          // { dg-error "flexible array member .A::a. not at end of .struct A." }
+  int b[];
+};
+
+struct B {
+  int i;
+  int a[];          // { dg-error "flexible array member .B::a. not at end of .struct B." }
+  int j;
+  int b[][2];
+};
+
+struct C {
+  int i;
+  struct {
+    int a[];        // { dg-error "flexible array member .C::<unnamed struct>::a. not at end of .struct C." }
+  };
+  int b[];
+};
+
+struct D {
+  int i;
+  struct {
+    int a[];        // { dg-error "flexible array member .D::<unnamed struct>::a. not at end of .struct D." }
+  } b[];
+  int c[];
+};
+
+struct E {
+  int i;
+  int a[0];
+  int b[];          // { dg-error "flexible array member .E::b. not at end of .struct E." }
+  int d[];
+};
+
+struct F {
+  int i;
+  int a[];          // { dg-error "flexible array member .F::a. not at end of .struct F." }
+  int b[], c[], d[];
+};
-- 
2.30.2