Hi!
As mentioned in the PR, we ICE because part of the body is genericized
twice and each time it wraps is_invisiref_parm RESULT_DECL (in this case,
could be also PARM_DEC) into REFERENCE_REF_P INDIRECT_REF.
The first time it is desirable, but when done again during VEC_INIT_EXPR
gimplification which calls cp_genericize_tree again, it is undesirable.
The following patch fixes it by only wrapping the invisiref parms/result
during the first cp_genericize_tree when the whole function is genericized.
I'd expect that any references to invisiref parms/result should be only
present in the VEC_INIT_EXPR arguments (which should be genericized already)
and that build_vec_init shouldn't create new ones out of the air.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
As mentioned in the PR, another option I see is special case
REFERENCE_REF_P INDIRECT_REFs and MEM_REFs into which they are gimplified
in cp_genericize_r by not changing is_invisiref_parm decls if they are
already wrapped in those.
2016-11-22 Jakub Jelinek <ja...@redhat.com>
PR c++/77739
* cp-gimplify.c (cp_gimplify_tree) <case VEC_INIT_EXPR>: Pass
false as handle_invisiref_parm_p to cp_genericize_tree.
(struct cp_genericize_data): Add handle_invisiref_parm_p field.
(cp_genericize_r): Don't wrap is_invisiref_parm into references
if !wtd->handle_invisiref_parm_p.
(cp_genericize_tree): Add handle_invisiref_parm_p argument,
set wtd.handle_invisiref_parm_p to it.
(cp_genericize): Pass true as handle_invisiref_parm_p to
cp_genericize_tree. Formatting fix.
* g++.dg/cpp1y/pr77739.C: New test.
--- gcc/cp/cp-gimplify.c.jj 2016-11-15 16:18:49.000000000 +0100
+++ gcc/cp/cp-gimplify.c 2016-11-22 19:12:07.606813783 +0100
@@ -38,7 +38,7 @@ along with GCC; see the file COPYING3.
static tree cp_genericize_r (tree *, int *, void *);
static tree cp_fold_r (tree *, int *, void *);
-static void cp_genericize_tree (tree*);
+static void cp_genericize_tree (tree*, bool);
static tree cp_fold (tree);
/* Local declarations. */
@@ -623,7 +623,7 @@ cp_gimplify_expr (tree *expr_p, gimple_s
tf_warning_or_error);
hash_set<tree> pset;
cp_walk_tree (expr_p, cp_fold_r, &pset, NULL);
- cp_genericize_tree (expr_p);
+ cp_genericize_tree (expr_p, false);
ret = GS_OK;
input_location = loc;
}
@@ -995,6 +995,7 @@ struct cp_genericize_data
struct cp_genericize_omp_taskreg *omp_ctx;
tree try_block;
bool no_sanitize_p;
+ bool handle_invisiref_parm_p;
};
/* Perform any pre-gimplification folding of C++ front end trees to
@@ -1111,7 +1112,7 @@ cp_genericize_r (tree *stmt_p, int *walk
}
/* Otherwise, do dereference invisible reference parms. */
- if (is_invisiref_parm (stmt))
+ if (wtd->handle_invisiref_parm_p && is_invisiref_parm (stmt))
{
*stmt_p = convert_from_reference (stmt);
*walk_subtrees = 0;
@@ -1511,7 +1512,7 @@ cp_genericize_r (tree *stmt_p, int *walk
/* Lower C++ front end trees to GENERIC in T_P. */
static void
-cp_genericize_tree (tree* t_p)
+cp_genericize_tree (tree* t_p, bool handle_invisiref_parm_p)
{
struct cp_genericize_data wtd;
@@ -1520,6 +1521,7 @@ cp_genericize_tree (tree* t_p)
wtd.omp_ctx = NULL;
wtd.try_block = NULL_TREE;
wtd.no_sanitize_p = false;
+ wtd.handle_invisiref_parm_p = handle_invisiref_parm_p;
cp_walk_tree (t_p, cp_genericize_r, &wtd, NULL);
delete wtd.p_set;
wtd.bind_expr_stack.release ();
@@ -1639,12 +1641,12 @@ cp_genericize (tree fndecl)
/* Expand all the array notations here. */
if (flag_cilkplus
&& contains_array_notation_expr (DECL_SAVED_TREE (fndecl)))
- DECL_SAVED_TREE (fndecl) =
- expand_array_notation_exprs (DECL_SAVED_TREE (fndecl));
+ DECL_SAVED_TREE (fndecl)
+ = expand_array_notation_exprs (DECL_SAVED_TREE (fndecl));
/* We do want to see every occurrence of the parms, so we can't just use
walk_tree's hash functionality. */
- cp_genericize_tree (&DECL_SAVED_TREE (fndecl));
+ cp_genericize_tree (&DECL_SAVED_TREE (fndecl), true);
if (flag_sanitize & SANITIZE_RETURN
&& do_ubsan_in_current_function ())
--- gcc/testsuite/g++.dg/cpp1y/pr77739.C.jj 2016-11-22 19:15:02.182659407
+0100
+++ gcc/testsuite/g++.dg/cpp1y/pr77739.C 2016-11-22 19:13:37.000000000
+0100
@@ -0,0 +1,15 @@
+// PR c++/77739
+// { dg-do compile { target c++14 } }
+
+struct A {
+ A();
+ A(const A &);
+};
+struct B {
+ B();
+ template <typename... Args> auto g(Args &&... p1) {
+ return [=] { f(p1...); };
+ }
+ void f(A, const char *);
+};
+B::B() { g(A(), ""); }
Jakub
