From 588d1952948769585bff991528868f4dec5db357 Mon Sep 17 00:00:00 2001
From: Joseph Myers <jsm@polyomino.org.uk>
Date: Wed, 22 Sep 2004 23:51:58 +0100
Subject: [PATCH] re PR c/16566 (ICE with flexible arrays)

	PR c/16566
	* c-typeck.c (build_component_ref): Don't special-case
	COMPOUND_EXPR.

testsuite:
	* gcc.c-torture/compile/pr16566-1.c,
	gcc.c-torture/compile/pr16566-2.c,
	gcc.c-torture/compile/pr16566-3.c: New tests.

From-SVN: r87892
---
 gcc/ChangeLog                                 |  6 ++++++
 gcc/c-typeck.c                                | 20 -------------------
 gcc/testsuite/ChangeLog                       |  7 +++++++
 .../gcc.c-torture/compile/pr16566-1.c         | 15 ++++++++++++++
 .../gcc.c-torture/compile/pr16566-2.c         | 13 ++++++++++++
 .../gcc.c-torture/compile/pr16566-3.c         | 12 +++++++++++
 6 files changed, 53 insertions(+), 20 deletions(-)
 create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr16566-1.c
 create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr16566-2.c
 create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr16566-3.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0d59f07fa33..b0fe994abfd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2004-09-22  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/16566
+	* c-typeck.c (build_component_ref): Don't special-case
+	COMPOUND_EXPR.
+
 2004-09-22  Frank Ch. Eigler  <fche@redhat.com>
 
 	* dominance.c (verify_dominators): Don't SEGV if recount_dominator
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index d94965b19a1..35678e04f31 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -1452,26 +1452,6 @@ build_component_ref (tree datum, tree component)
   if (!objc_is_public (datum, component))
     return error_mark_node;
 
-  /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
-     Ensure that the arguments are not lvalues; otherwise,
-     if the component is an array, it would wrongly decay to a pointer in
-     C89 mode.
-     We cannot do this with a COND_EXPR, because in a conditional expression
-     the default promotions are applied to both sides, and this would yield
-     the wrong type of the result; for example, if the components have
-     type "char".  */
-  switch (TREE_CODE (datum))
-    {
-    case COMPOUND_EXPR:
-      {
-	tree value = build_component_ref (TREE_OPERAND (datum, 1), component);
-	return build2 (COMPOUND_EXPR, TREE_TYPE (value),
-		       TREE_OPERAND (datum, 0), non_lvalue (value));
-      }
-    default:
-      break;
-    }
-
   /* See if there is a field or component with name COMPONENT.  */
 
   if (code == RECORD_TYPE || code == UNION_TYPE)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d6226d5f85d..70f7b6f238b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2004-09-22  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/16566
+	* gcc.c-torture/compile/pr16566-1.c,
+	gcc.c-torture/compile/pr16566-2.c,
+	gcc.c-torture/compile/pr16566-3.c: New tests.
+
 2004-09-22  Kazu Hirata  <kazu@cs.umass.edu>
 
 	PR tree-optimization/17512
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr16566-1.c b/gcc/testsuite/gcc.c-torture/compile/pr16566-1.c
new file mode 100644
index 00000000000..4ed4ab730e6
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr16566-1.c
@@ -0,0 +1,15 @@
+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (comment #3).  */
+
+struct S;
+
+struct C {
+    int i;
+    struct S *tab[];
+};
+
+struct S { struct C c; };
+
+void foo (struct S *x) {
+  foo(((void)1, x->c).tab[0]);
+}
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr16566-2.c b/gcc/testsuite/gcc.c-torture/compile/pr16566-2.c
new file mode 100644
index 00000000000..c0036f0fc64
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr16566-2.c
@@ -0,0 +1,13 @@
+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (comment #5).  */
+
+struct A
+{
+    int i;
+    int x[];
+};
+
+int foo(struct A a)
+{ 
+    return (a,a).x[0];
+}
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr16566-3.c b/gcc/testsuite/gcc.c-torture/compile/pr16566-3.c
new file mode 100644
index 00000000000..954aa361da2
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr16566-3.c
@@ -0,0 +1,12 @@
+/* ICE with flexible arrays in non-lvalue structures.  Bug 16566
+   (testcase from duplicate bug 16575).  */
+
+struct S;
+struct C {
+    int i;
+    struct S *tab[];
+};
+struct S { struct C c; };
+void foo (struct S *x) {
+  ((void)1, x->c).tab[0] = 0;
+}
-- 
2.30.2