[gcc r9-9443] expand: Fix up LTO ICE with COMPOUND_LITERAL_EXPR [PR99849]

[Jakub Jelinek <jakub@gcc.gnu.org>]

https://gcc.gnu.org/g:49a7e7d0fc5fcc28ed13b6d67faf99a5dfe03f65

commit r9-9443-g49a7e7d0fc5fcc28ed13b6d67faf99a5dfe03f65
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Sat Apr 10 12:49:01 2021 +0200

    expand: Fix up LTO ICE with COMPOUND_LITERAL_EXPR [PR99849]
    
    The gimplifier optimizes away COMPOUND_LITERAL_EXPRs, but they can remain
    in the form of ADDR_EXPR of COMPOUND_LITERAL_EXPRs in static initializers.
    By the TREE_STATIC check I meant to check that the underlying decl of
    the compound literal is a global rather than automatic variable which
    obviously can't be referenced in static initializers, but unfortunately
    with LTO it might end up in another partition and thus be DECL_EXTERNAL
    instead.
    
    2021-04-10  Jakub Jelinek  <jakub@redhat.com>
    
            PR lto/99849
            * expr.c (expand_expr_addr_expr_1): Test is_global_var rather than
            just TREE_STATIC on COMPOUND_LITERAL_EXPR_DECLs.
    
            * gcc.dg/lto/pr99849_0.c: New test.
    
    (cherry picked from commit 2e57bc7eedb084869d17fe07b538d907b8fee819)

Diff:
---
 gcc/expr.c                           |  2 +-
 gcc/testsuite/gcc.dg/lto/pr99849_0.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/gcc/expr.c b/gcc/expr.c
index fa15b7eceae..1ac5faec67c 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -7967,7 +7967,7 @@ expand_expr_addr_expr_1 (tree exp, rtx target, scalar_int_mode tmode,
 	 array with address of COMPOUND_LITERAL_EXPR in DECL_INITIAL;
 	 the initializers aren't gimplified.  */
       if (COMPOUND_LITERAL_EXPR_DECL (exp)
-	  && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)))
+	  && is_global_var (COMPOUND_LITERAL_EXPR_DECL (exp)))
 	return expand_expr_addr_expr_1 (COMPOUND_LITERAL_EXPR_DECL (exp),
 					target, tmode, modifier, as);
       /* FALLTHRU */
diff --git a/gcc/testsuite/gcc.dg/lto/pr99849_0.c b/gcc/testsuite/gcc.dg/lto/pr99849_0.c
new file mode 100644
index 00000000000..d489cee0f52
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr99849_0.c
@@ -0,0 +1,23 @@
+/* PR lto/99849 */
+/* { dg-lto-do link } */
+/* { dg-require-effective-target fpic } */
+/* { dg-require-effective-target shared } */
+/* { dg-extra-ld-options { -shared } } */
+/* { dg-lto-options { { -flto -flto-partition=1to1 -O2 -Wno-incompatible-pointer-types -Wno-discarded-qualifiers -fPIC } } } */
+
+struct { struct A *a; } *b;
+struct B { int *b; };
+struct C { int *c; };
+const struct D { struct C d; } d;
+struct A { struct { struct C e; }; };
+struct E { void *e; } e = { &( &(const struct D) { (void *) &d })->d };
+struct C f = { &( &(const struct D) { (void *) &d })->d };
+struct A g[] = { &e, &f };
+void foo () { b->a = g; }
+struct E h = { foo };
+void bar ();
+int baz () { bar (h); }
+struct B i = { (int *) baz };
+void qux ();
+void corge () { qux (i); }
+void *j __attribute__((__used__)) = corge;