[PR69315] enable finish_function to recurse for constexpr functions
Jakub Jelinek
jakub@redhat.com
Wed Mar 23 16:24:00 GMT 2016
On Wed, Mar 23, 2016 at 02:57:36PM +0100, Jakub Jelinek wrote:
> On Tue, Mar 22, 2016 at 05:28:10PM -0400, Jason Merrill wrote:
> > Jakub, you added defer_mark_used_calls for BZ 37189, do you think it's still
> > needed? The testcase passes without it now.
>
> That's a question. Digging through history, I found:
> 1) r149750 aka gimplification unit-at-a-time
> 2) PR48869 that fixed the regression caused by that; so we now should be
> trying to get_copy_ctor/get_dtor for parallel/task already during
> cp-genericize.c
> But, looking at this function, e.g. taskloop construct isn't handled,
> will try to construct a testcase where it could matter. Dunno about OpenACC
> or Cilk+ constructs, those aren't handled during cp-gimplify.c either.
> Though, as we have gimplification unit-at-a-time, I'd say that even if we
> synthetize_method during gimplification of something, we'd still enqueue it
> in cgraph for later analysis instead of gimplification right away.
> The gimplifier still asserts that it isn't called recursively, so I'd hope
> the patch can be reverted (test kept).
I'll test then following (had to tweak the testcase a little bit, put c++11
into target, move it to proper dir, and build with -O2 (as starting with
r233671 we don't ICE on the testcase when -fno-inline, which is the default
at -O0).
2016-03-23 Alexandre Oliva <aoliva@redhat.com>
Jason Merrill <jason@redhat.com>
Jakub Jelinek <jakub@redhat.com>
PR c++/69315
* cp-tree.h (defer_mark_used_calls, deferred_mark_used_calls): Remove.
* decl.c (defer_mark_used_calls, deferred_mark_used_calls): Remove.
(finish_function): Don't set or test them.
* decl2.c (mark_used): Don't handle defer_mark_used_calls.
* g++.dg/cpp0x/constexpr-69315.C: New test.
* g++.dg/cpp0x/variadic122.C: Change one dg-warning into dg-bogus.
--- gcc/cp/cp-tree.h.jj 2016-03-21 10:12:31.000000000 +0100
+++ gcc/cp/cp-tree.h 2016-03-23 16:38:46.193501388 +0100
@@ -5846,8 +5846,6 @@ extern tree fndecl_declared_return_type
extern bool undeduced_auto_decl (tree);
extern void require_deduced_type (tree);
-extern bool defer_mark_used_calls;
-extern GTY(()) vec<tree, va_gc> *deferred_mark_used_calls;
extern tree finish_case_label (location_t, tree, tree);
extern tree cxx_maybe_build_cleanup (tree, tsubst_flags_t);
--- gcc/cp/decl.c.jj 2016-03-22 09:05:31.000000000 +0100
+++ gcc/cp/decl.c 2016-03-23 16:39:11.563158827 +0100
@@ -227,11 +227,6 @@ struct GTY((for_user)) named_label_entry
function, two inside the body of a function in a local class, etc.) */
int function_depth;
-/* To avoid unwanted recursion, finish_function defers all mark_used calls
- encountered during its execution until it finishes. */
-bool defer_mark_used_calls;
-vec<tree, va_gc> *deferred_mark_used_calls;
-
/* States indicating how grokdeclarator() should handle declspecs marked
with __attribute__((deprecated)). An object declared as
__attribute__((deprecated)) suppresses warnings of uses of other
@@ -14594,9 +14589,6 @@ finish_function (int flags)
if (c_dialect_objc ())
objc_finish_function ();
- gcc_assert (!defer_mark_used_calls);
- defer_mark_used_calls = true;
-
record_key_method_defined (fndecl);
fntype = TREE_TYPE (fndecl);
@@ -14846,17 +14838,6 @@ finish_function (int flags)
/* Clean up. */
current_function_decl = NULL_TREE;
- defer_mark_used_calls = false;
- if (deferred_mark_used_calls)
- {
- unsigned int i;
- tree decl;
-
- FOR_EACH_VEC_SAFE_ELT (deferred_mark_used_calls, i, decl)
- mark_used (decl);
- vec_free (deferred_mark_used_calls);
- }
-
invoke_plugin_callbacks (PLUGIN_FINISH_PARSE_FUNCTION, fndecl);
return fndecl;
}
--- gcc/cp/decl2.c.jj 2016-02-19 08:55:04.000000000 +0100
+++ gcc/cp/decl2.c 2016-03-23 16:39:28.604928715 +0100
@@ -5140,14 +5140,6 @@ mark_used (tree decl, tsubst_flags_t com
if (DECL_ODR_USED (decl))
return true;
- /* If within finish_function, defer the rest until that function
- finishes, otherwise it might recurse. */
- if (defer_mark_used_calls)
- {
- vec_safe_push (deferred_mark_used_calls, decl);
- return true;
- }
-
/* Normally, we can wait until instantiation-time to synthesize DECL.
However, if DECL is a static data member initialized with a constant
or a constexpr function, we need it right now because a reference to
--- gcc/testsuite/g++.dg/cpp0x/constexpr-69315.C.jj 2016-03-23 16:48:59.675217676 +0100
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-69315.C 2016-03-23 16:46:37.000000000 +0100
@@ -0,0 +1,35 @@
+// PR c++/69315
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2" }
+
+// Template instantiation and evaluation for folding within
+// finish_function may call finish_function recursively.
+// Make sure we don't reject or delay that sort of recursion.
+
+template <bool> struct Iter;
+
+struct Arg {
+ Iter<true> begin();
+ Iter<true> end();
+};
+
+template <bool> struct Iter {
+ int operator*();
+ Iter operator++();
+ template <bool C1, bool C2> friend constexpr bool operator==(Iter<C1>, Iter<C2>);
+ template <bool C1, bool C2> friend constexpr bool operator!=(Iter<C1>, Iter<C2>);
+};
+
+void func(Arg a) {
+ for (auto ch : a) {
+ a.begin() == a.end();
+ }
+}
+
+template <bool C1, bool C2> constexpr bool operator==(Iter<C1>, Iter<C2>) {
+ return true;
+}
+
+template <bool C1, bool C2> constexpr bool operator!=(Iter<C1> a, Iter<C2> b) {
+ return a == b;
+}
--- gcc/testsuite/g++.dg/cpp0x/variadic122.C.jj 2014-03-10 10:50:13.000000000 +0100
+++ gcc/testsuite/g++.dg/cpp0x/variadic122.C 2016-03-23 16:54:10.000000000 +0100
@@ -9,7 +9,7 @@ template < class T > struct Container
template < class T >
T deref (T)
-{} // { dg-warning "no return" }
+{} // { dg-bogus "no return" }
template < class T, class ... Args >
auto deref (T u, int, Args ... args)->decltype (deref (u.f (), args ...))
Jakub
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