The following patch makes sure we wrap symbol references in global
initializers the same as we do for IL references - inside a MEM_REF
that guards their context against type changes due to symbol merging
(and thus in this case against ICEs when processing an ARRAY_REF
around a non-array object).
LTO bootstrap & regtest running on x86_64-unknown-linux-gnu.
Richard.
2014-03-31 Richard Biener <rguent...@suse.de>
PR lto/60720
* lto-streamer-out.c (wrap_refs): New function.
(get_symbol_initial_value): Wrap symbol references in global
initializes in type-preserving MEM_REFs.
* gcc.dg/lto/pr60720_0.c: New testcase.
* gcc.dg/lto/pr60720_1.c: Likewise.
Index: gcc/lto-streamer-out.c
===================================================================
*** gcc/lto-streamer-out.c (revision 208955)
--- gcc/lto-streamer-out.c (working copy)
*************** lto_is_streamable (tree expr)
*** 313,318 ****
--- 313,339 ----
}
+ /* Wrap symbol references in *TP inside a type-preserving MEM_REF. */
+
+ static tree
+ wrap_refs (tree *tp, int *ws, void *)
+ {
+ tree t = *tp;
+ if (TREE_CODE (t) == VAR_DECL)
+ {
+ tree ptrtype = build_pointer_type (TREE_TYPE (t));
+ *tp = build2 (MEM_REF, TREE_TYPE (t),
+ build1 (ADDR_EXPR, ptrtype, t),
+ build_int_cst (ptrtype, 0));
+ *ws = 0;
+ }
+ else if (TREE_CODE (t) == CONSTRUCTOR)
+ ;
+ else if (!EXPR_P (t))
+ *ws = 0;
+ return NULL_TREE;
+ }
+
/* For EXPR lookup and return what we want to stream to OB as DECL_INITIAL.
*/
static tree
*************** get_symbol_initial_value (struct output_
*** 340,345 ****
--- 361,374 ----
initial = error_mark_node;
}
+ /* Wrap all symbol references inside the initializer in a MEM_REF
+ to preserve the type at the use even in case the symbol is
+ prevailed by one with a different type. We can safely skip this
+ during WPA. */
+ if (!in_lto_p
+ && initial && initial != error_mark_node)
+ walk_tree (&initial, wrap_refs, NULL, NULL);
+
return initial;
}
Index: gcc/testsuite/gcc.dg/lto/pr60720_0.c
===================================================================
*** gcc/testsuite/gcc.dg/lto/pr60720_0.c (revision 0)
--- gcc/testsuite/gcc.dg/lto/pr60720_0.c (working copy)
***************
*** 0 ****
--- 1,15 ----
+ /* { dg-lto-do run } */
+ /* { dg-extra-ld-options { -w } } */
+
+ /* ??? lto.exp does not allow to scan for
+ :1:12: warning: type of 'x' does not match original declaration
+ extern int x[];
+ ^
+ :1:5: note: previously declared here
+ int x;
+ ^ */
+
+ extern int x[];
+ int *foo[] = { &x[0] };
+
+ int main() { return *foo[0]; }
Index: gcc/testsuite/gcc.dg/lto/pr60720_1.c
===================================================================
*** gcc/testsuite/gcc.dg/lto/pr60720_1.c (revision 0)
--- gcc/testsuite/gcc.dg/lto/pr60720_1.c (working copy)
***************
*** 0 ****
--- 1 ----
+ int x;
