[PATCH] middle-end/94479 - fix gimplification of address

[Richard Biener]

When gimplifying an address operand we may expose an indirect
ref via DECL_VALUE_EXPR for example.  This is dealt with in the
code already but it fails to consider that INDIRECT_REFs get
gimplified to MEM_REFs.

Fixed which makes the ICE observed on x86_64-netbsd go away.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2020-04-07  Richard Biener  <rguent...@suse.de>

        PR middle-end/94479
        * gimplify.c (gimplify_addr_expr): Also consider generated
        MEM_REFs.

        * gcc.dg/torture/pr94479.c: New testcase.
---
 gcc/gimplify.c                         |  4 +++-
 gcc/testsuite/gcc.dg/torture/pr94479.c | 12 ++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr94479.c

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 787435c38cd..8cdfae26510 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -6181,7 +6181,9 @@ gimplify_addr_expr (tree *expr_p, gimple_seq *pre_p, 
gimple_seq *post_p)
 
       /* For various reasons, the gimplification of the expression
         may have made a new INDIRECT_REF.  */
-      if (TREE_CODE (op0) == INDIRECT_REF)
+      if (TREE_CODE (op0) == INDIRECT_REF
+         || (TREE_CODE (op0) == MEM_REF
+             && integer_zerop (TREE_OPERAND (op0, 1))))
        goto do_indirect_ref;
 
       mark_addressable (TREE_OPERAND (expr, 0));
diff --git a/gcc/testsuite/gcc.dg/torture/pr94479.c 
b/gcc/testsuite/gcc.dg/torture/pr94479.c
new file mode 100644
index 00000000000..53285bb4f38
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr94479.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-require-stack-check "specific" } */
+/* { dg-additional-options "-fstack-check -w" } */
+
+int a;
+struct b {
+    char c;
+    void *d;  
+};
+struct b e() {
+    struct b f[] = {{}, "", f, a};
+}
-- 
2.25.1