On Tue, Aug 18, 2015 at 10:45:21AM +0200, Richard Biener wrote:
> On Mon, Aug 17, 2015 at 7:31 PM, Jeff Law <l...@redhat.com> wrote:
> > But in walking through all that, I think I've stumbled on a simpler
> > solution. Specifically do as a little as possible and let the standard
> > mechanisms clean things up :-)
> >
> > 1. Delete the code that removes instructions after the trap.
> >
> > 2. Split the block immediately after the trap and remove the edge
> > from the original block (with the trap) to the new block.
>
> cfg-cleanup will do that for you if you have a not returning stmt ending
> the previous block.
The following patch hopefully does what's oulined above.
Arguably I should have renamed the insert_trap_and_remove_trailing_statements
to something more descriptive, e.g. insert_trap_and_split_block. Your
call.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2015-08-18 Marek Polacek <pola...@redhat.com>
PR middle-end/67133
* gimple-ssa-isolate-paths.c
(insert_trap_and_remove_trailing_statements): Rename to ...
(insert_trap): ... this. Don't remove trailing statements; split
block instead.
(find_explicit_erroneous_behaviour): Don't remove all outgoing edges.
* g++.dg/torture/pr67133.C: New test.
diff --git gcc/gimple-ssa-isolate-paths.c gcc/gimple-ssa-isolate-paths.c
index 6f84f85..ca2322d 100644
--- gcc/gimple-ssa-isolate-paths.c
+++ gcc/gimple-ssa-isolate-paths.c
@@ -66,10 +66,10 @@ check_loadstore (gimple stmt, tree op, tree, void *data)
return false;
}
-/* Insert a trap after SI and remove SI and all statements after the trap. */
+/* Insert a trap after SI and split the block after the trap. */
static void
-insert_trap_and_remove_trailing_statements (gimple_stmt_iterator *si_p, tree
op)
+insert_trap (gimple_stmt_iterator *si_p, tree op)
{
/* We want the NULL pointer dereference to actually occur so that
code that wishes to catch the signal can do so.
@@ -115,18 +115,8 @@ insert_trap_and_remove_trailing_statements
(gimple_stmt_iterator *si_p, tree op)
else
gsi_insert_before (si_p, seq, GSI_NEW_STMT);
- /* We must remove statements from the end of the block so that we
- never reference a released SSA_NAME. */
- basic_block bb = gimple_bb (gsi_stmt (*si_p));
- for (gimple_stmt_iterator si = gsi_last_bb (bb);
- gsi_stmt (si) != gsi_stmt (*si_p);
- si = gsi_last_bb (bb))
- {
- stmt = gsi_stmt (si);
- unlink_stmt_vdef (stmt);
- gsi_remove (&si, true);
- release_defs (stmt);
- }
+ split_block (gimple_bb (new_stmt), new_stmt);
+ *si_p = gsi_for_stmt (stmt);
}
/* BB when reached via incoming edge E will exhibit undefined behaviour
@@ -215,7 +205,7 @@ isolate_path (basic_block bb, basic_block duplicate,
update_stmt (ret);
}
else
- insert_trap_and_remove_trailing_statements (&si2, op);
+ insert_trap (&si2, op);
}
return duplicate;
@@ -422,14 +412,8 @@ find_explicit_erroneous_behaviour (void)
continue;
}
- insert_trap_and_remove_trailing_statements (&si,
- null_pointer_node);
-
- /* And finally, remove all outgoing edges from BB. */
- edge e;
- for (edge_iterator ei = ei_start (bb->succs);
- (e = ei_safe_edge (ei)); )
- remove_edge (e);
+ insert_trap (&si, null_pointer_node);
+ bb = gimple_bb (gsi_stmt (si));
/* Ignore any more operands on this statement and
continue the statement iterator (which should
diff --git gcc/testsuite/g++.dg/torture/pr67133.C
gcc/testsuite/g++.dg/torture/pr67133.C
index e69de29..0f23572 100644
--- gcc/testsuite/g++.dg/torture/pr67133.C
+++ gcc/testsuite/g++.dg/torture/pr67133.C
@@ -0,0 +1,46 @@
+// { dg-do compile }
+// { dg-additional-options "-fisolate-erroneous-paths-attribute" }
+
+class A;
+struct B {
+ typedef A type;
+};
+template <typename> struct I : B {};
+class C {
+public:
+ C(char *);
+ int size();
+};
+template <typename> struct D;
+template <typename _Tp, typename = D<_Tp>> class F {
+ class G {
+ template <typename> static _Tp *__test();
+ typedef int _Del;
+
+ public:
+ typedef decltype(__test<_Del>()) type;
+ };
+
+public:
+ typename I<_Tp>::type operator*() {
+ typename G::type a = 0;
+ return *a;
+ }
+};
+class H {
+ F<A> Out;
+ H();
+};
+void fn1(void *, void *, int) __attribute__((__nonnull__));
+class A {
+ int OutBufEnd, OutBufCur;
+
+public:
+ void operator<<(C p1) {
+ int b, c = p1.size();
+ if (OutBufEnd)
+ fn1(&OutBufCur, &b, c);
+ }
+};
+char* a;
+H::H() { *Out << a; }
Marek
