Hi!
The following testcase ICEs, because the VLA ARRAY_TYPE in the ctor
isn't considered variably_modified_type_p during cloning of the ctor
when the types weren't gimplified yet.
The size is a non-constant expression that has SAVE_EXPR of a global
VAR_DECL in it, so when variably_modified_type_p is called with non-NULL
second argument, it returns NULL, we share the ARRAY_TYPE in between
the abstract ctor origin and and the base_ctor and comp_ctor clones,
later on when gimplifying the first of the clones gimplify_one_sizepos
actually replaces the expression with a local temporary VAR_DECL and from
that point it is variably_modified_type_p in the base ctor. But
it is a var from different function in the other ctor and var with
a location in the abstract origin which causes dwarf2out.c ICE.
This patch fixes it by returning true also for non-gimplified types
where gimplify_one_sizepos is expected to turn that into a local temporary.
It seems frontends usually call variably_modified_type_p with
NULL as last argument, with non-NULL argument it is only used during
tree-nested.c/omp-low.c (which happens after gimplification), tree-inline.c
(which usually happens after gimplification, with the exception of cdtor
cloning, at least can't find anything else).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-10-23 Jakub Jelinek <ja...@redhat.com>
PR debug/54828
* tree.c (RETURN_TRUE_IF_VAR): Return true also if
!TYPE_SIZES_GIMPLIFIED (type) and _t is going to be gimplified
into a local temporary.
* g++.dg/debug/pr54828.C: New test.
--- gcc/tree.c.jj 2012-10-19 11:01:07.000000000 +0200
+++ gcc/tree.c 2012-10-23 14:46:24.846195605 +0200
@@ -8467,14 +8467,21 @@ variably_modified_type_p (tree type, tre
tree t;
/* Test if T is either variable (if FN is zero) or an expression containing
- a variable in FN. */
+ a variable in FN. If TYPE isn't gimplified, return true also if
+ gimplify_one_sizepos would gimplify the expression into a local
+ variable. */
#define RETURN_TRUE_IF_VAR(T) \
do { tree _t = (T); \
if (_t != NULL_TREE
\
&& _t != error_mark_node \
&& TREE_CODE (_t) != INTEGER_CST \
&& TREE_CODE (_t) != PLACEHOLDER_EXPR \
- && (!fn || walk_tree (&_t, find_var_from_fn, fn, NULL))) \
+ && (!fn \
+ || (!TYPE_SIZES_GIMPLIFIED (type) \
+ && !TREE_CONSTANT (_t) \
+ && TREE_CODE (_t) != VAR_DECL \
+ && !CONTAINS_PLACEHOLDER_P (_t)) \
+ || walk_tree (&_t, find_var_from_fn, fn, NULL))) \
return true; } while (0)
if (type == error_mark_node)
--- gcc/testsuite/g++.dg/debug/pr54828.C.jj 2012-10-23 14:30:13.194012566
+0200
+++ gcc/testsuite/g++.dg/debug/pr54828.C 2012-10-23 14:30:07.000000000
+0200
@@ -0,0 +1,14 @@
+// PR debug/54828
+// { dg-do compile }
+// { dg-options "-g" }
+
+struct T { T (); virtual ~T (); };
+struct S : public virtual T { S (); virtual ~S (); };
+int v;
+void foo (char *);
+
+S::S ()
+{
+ char s[v];
+ foo (s);
+}
Jakub
