* [PATCH] Fix another ipa-split caused ICE (PR ipa/69241)
@ 2016-02-10 22:32 Jakub Jelinek
2016-02-11 9:22 ` Richard Biener
0 siblings, 1 reply; 5+ messages in thread
From: Jakub Jelinek @ 2016-02-10 22:32 UTC (permalink / raw)
To: Richard Biener; +Cc: gcc-patches
Hi!
Markus has pointed out to a reduced testcase which still ICEs even with the
PR69241 fix. In that case the function with TREE_ADDRESSABLE return type
does not return at all (and -Wreturn-type properly diagnoses it).
For that case the following patch just forces the lhs on the *.part.*
call, so that we don't ICE in assign_temp.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2016-02-10 Jakub Jelinek <jakub@redhat.com>
PR ipa/69241
* ipa-split.c (split_function): If split part returns TREE_ADDRESSABLE
type by reference, force lhs on the call.
* g++.dg/ipa/pr69241-4.C: New test.
--- gcc/ipa-split.c.jj 2016-02-10 16:05:37.000000000 +0100
+++ gcc/ipa-split.c 2016-02-10 17:18:12.553061670 +0100
@@ -1589,7 +1589,20 @@ split_function (basic_block return_bb, s
}
}
else
- gsi_insert_after (&gsi, call, GSI_NEW_STMT);
+ {
+ /* Force a lhs if the split part has to return a value. */
+ if (split_point->split_part_set_retval
+ && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
+ {
+ retval = DECL_RESULT (current_function_decl);
+ if (TREE_ADDRESSABLE (TREE_TYPE (TREE_TYPE (retval))))
+ {
+ retval = get_or_create_ssa_default_def (cfun, retval);
+ gimple_call_set_lhs (call, build_simple_mem_ref (retval));
+ }
+ }
+ gsi_insert_after (&gsi, call, GSI_NEW_STMT);
+ }
if (tsan_func_exit_call)
gsi_insert_after (&gsi, tsan_func_exit_call, GSI_NEW_STMT);
}
--- gcc/testsuite/g++.dg/ipa/pr69241-4.C.jj 2016-02-10 17:22:03.977866326 +0100
+++ gcc/testsuite/g++.dg/ipa/pr69241-4.C 2016-02-10 17:22:00.073920229 +0100
@@ -0,0 +1,55 @@
+// PR ipa/69241
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2 -Wno-return-type" }
+
+template <typename> class A;
+struct B {
+ using pointer = int *;
+};
+template <typename _CharT, typename = A<_CharT>> class basic_string {
+ long _M_string_length;
+ enum { _S_local_capacity = 15 } _M_local_buf[_S_local_capacity];
+ B::pointer _M_local_data;
+
+public:
+ ~basic_string();
+};
+template <typename _CharT, typename _Traits, typename _Alloc>
+int operator<<(_Traits, basic_string<_CharT, _Alloc>);
+class C {
+ basic_string<A<char>> _M_string;
+};
+class D {
+ C _M_stringbuf;
+};
+class F {
+ int stream;
+ D stream_;
+};
+class G {
+public:
+ void operator&(int);
+};
+class H {
+public:
+ H(unsigned);
+ H(H &&);
+ bool m_fn1();
+};
+class I {
+ void m_fn2(const int &&);
+ static H m_fn3(const int &);
+};
+template <typename Functor> void Bind(Functor);
+class J {
+public:
+ static basic_string<char> m_fn4();
+};
+int a;
+void I::m_fn2(const int &&) { Bind(m_fn3); }
+H I::m_fn3(const int &) {
+ !false ? (void)0 : G() & F() << J::m_fn4();
+ H b(a);
+ if (b.m_fn1())
+ F();
+}
Jakub
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix another ipa-split caused ICE (PR ipa/69241)
2016-02-10 22:32 [PATCH] Fix another ipa-split caused ICE (PR ipa/69241) Jakub Jelinek
@ 2016-02-11 9:22 ` Richard Biener
2016-02-11 16:14 ` Jakub Jelinek
2016-02-11 20:17 ` Jeff Law
0 siblings, 2 replies; 5+ messages in thread
From: Richard Biener @ 2016-02-11 9:22 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: gcc-patches, Jan Hubicka
On Wed, 10 Feb 2016, Jakub Jelinek wrote:
> Hi!
>
> Markus has pointed out to a reduced testcase which still ICEs even with the
> PR69241 fix. In that case the function with TREE_ADDRESSABLE return type
> does not return at all (and -Wreturn-type properly diagnoses it).
> For that case the following patch just forces the lhs on the *.part.*
> call, so that we don't ICE in assign_temp.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Um... I wonder if it wouldn't be better to force such functions to
be noreturn by say, placing a __builtin_unreachable () at the missing
return and maybe even adjust the return type.
In the frontend I mean.
After all, what would the code below do at runtime? Unhelpfully
write to a random memory location. So if then I'd rather
dereference literal zero here (well, not sure what to do for
-fno-delete-null-pointer targets). Otherwise this becomes a bigger
security issue than not initializing the not used return value?
The other option is to simply not split the function in this case.
Richard.
> 2016-02-10 Jakub Jelinek <jakub@redhat.com>
>
> PR ipa/69241
> * ipa-split.c (split_function): If split part returns TREE_ADDRESSABLE
> type by reference, force lhs on the call.
>
> * g++.dg/ipa/pr69241-4.C: New test.
>
> --- gcc/ipa-split.c.jj 2016-02-10 16:05:37.000000000 +0100
> +++ gcc/ipa-split.c 2016-02-10 17:18:12.553061670 +0100
> @@ -1589,7 +1589,20 @@ split_function (basic_block return_bb, s
> }
> }
> else
> - gsi_insert_after (&gsi, call, GSI_NEW_STMT);
> + {
> + /* Force a lhs if the split part has to return a value. */
> + if (split_point->split_part_set_retval
> + && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
> + {
> + retval = DECL_RESULT (current_function_decl);
> + if (TREE_ADDRESSABLE (TREE_TYPE (TREE_TYPE (retval))))
> + {
> + retval = get_or_create_ssa_default_def (cfun, retval);
> + gimple_call_set_lhs (call, build_simple_mem_ref (retval));
> + }
> + }
> + gsi_insert_after (&gsi, call, GSI_NEW_STMT);
> + }
> if (tsan_func_exit_call)
> gsi_insert_after (&gsi, tsan_func_exit_call, GSI_NEW_STMT);
> }
> --- gcc/testsuite/g++.dg/ipa/pr69241-4.C.jj 2016-02-10 17:22:03.977866326 +0100
> +++ gcc/testsuite/g++.dg/ipa/pr69241-4.C 2016-02-10 17:22:00.073920229 +0100
> @@ -0,0 +1,55 @@
> +// PR ipa/69241
> +// { dg-do compile { target c++11 } }
> +// { dg-options "-O2 -Wno-return-type" }
> +
> +template <typename> class A;
> +struct B {
> + using pointer = int *;
> +};
> +template <typename _CharT, typename = A<_CharT>> class basic_string {
> + long _M_string_length;
> + enum { _S_local_capacity = 15 } _M_local_buf[_S_local_capacity];
> + B::pointer _M_local_data;
> +
> +public:
> + ~basic_string();
> +};
> +template <typename _CharT, typename _Traits, typename _Alloc>
> +int operator<<(_Traits, basic_string<_CharT, _Alloc>);
> +class C {
> + basic_string<A<char>> _M_string;
> +};
> +class D {
> + C _M_stringbuf;
> +};
> +class F {
> + int stream;
> + D stream_;
> +};
> +class G {
> +public:
> + void operator&(int);
> +};
> +class H {
> +public:
> + H(unsigned);
> + H(H &&);
> + bool m_fn1();
> +};
> +class I {
> + void m_fn2(const int &&);
> + static H m_fn3(const int &);
> +};
> +template <typename Functor> void Bind(Functor);
> +class J {
> +public:
> + static basic_string<char> m_fn4();
> +};
> +int a;
> +void I::m_fn2(const int &&) { Bind(m_fn3); }
> +H I::m_fn3(const int &) {
> + !false ? (void)0 : G() & F() << J::m_fn4();
> + H b(a);
> + if (b.m_fn1())
> + F();
> +}
>
> Jakub
>
>
--
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] Fix another ipa-split caused ICE (PR ipa/69241)
2016-02-11 9:22 ` Richard Biener
@ 2016-02-11 16:14 ` Jakub Jelinek
2016-02-12 11:36 ` Richard Biener
2016-02-11 20:17 ` Jeff Law
1 sibling, 1 reply; 5+ messages in thread
From: Jakub Jelinek @ 2016-02-11 16:14 UTC (permalink / raw)
To: Richard Biener, Jan Hubicka; +Cc: gcc-patches
On Thu, Feb 11, 2016 at 10:22:24AM +0100, Richard Biener wrote:
> The other option is to simply not split the function in this case.
Here is a better fix (but it needs the other patch I've sent, so that
what is return_bb stays the same).
This patch arranges for the case where there is return_bb, but does not
return a value, in function that has return type TREE_ADDRESSABLE,
to just use void return type from the split part (because we would never
set lhs of the call to *.part.* in that case anyway).
Bootstrapped/regtested on x86_64-linux and i686-linux on top of the PR68672
patch, ok for trunk?
2016-02-10 Jakub Jelinek <jakub@redhat.com>
PR ipa/69241
* ipa-split.c (split_function): If split part returns TREE_ADDRESSABLE
type by reference, force lhs on the call.
* g++.dg/ipa/pr69241-4.C: New test.
--- gcc/ipa-split.c.jj 2016-02-11 12:46:15.975777652 +0100
+++ gcc/ipa-split.c 2016-02-11 13:06:57.715241871 +0100
@@ -629,7 +629,18 @@ consider_split (struct split_point *curr
4) For non-SSA we need to look where the var is computed. */
retval = find_retval (return_bb);
if (!retval)
- current->split_part_set_retval = true;
+ {
+ /* If there is a return_bb with no return value in function returning
+ value by reference, also make the split part return void, otherwise
+ we expansion would try to create a non-POD temporary, which is
+ invalid. */
+ if (return_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
+ && DECL_RESULT (current_function_decl)
+ && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
+ current->split_part_set_retval = false;
+ else
+ current->split_part_set_retval = true;
+ }
else if (is_gimple_min_invariant (retval))
current->split_part_set_retval = false;
/* Special case is value returned by reference we record as if it was non-ssa
--- gcc/testsuite/g++.dg/ipa/pr69241-4.C.jj 2016-02-11 13:00:04.160075417 +0100
+++ gcc/testsuite/g++.dg/ipa/pr69241-4.C 2016-02-11 13:00:04.160075417 +0100
@@ -0,0 +1,55 @@
+// PR ipa/69241
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2 -Wno-return-type" }
+
+template <typename> class A;
+struct B {
+ using pointer = int *;
+};
+template <typename _CharT, typename = A<_CharT>> class basic_string {
+ long _M_string_length;
+ enum { _S_local_capacity = 15 } _M_local_buf[_S_local_capacity];
+ B::pointer _M_local_data;
+
+public:
+ ~basic_string();
+};
+template <typename _CharT, typename _Traits, typename _Alloc>
+int operator<<(_Traits, basic_string<_CharT, _Alloc>);
+class C {
+ basic_string<A<char>> _M_string;
+};
+class D {
+ C _M_stringbuf;
+};
+class F {
+ int stream;
+ D stream_;
+};
+class G {
+public:
+ void operator&(int);
+};
+class H {
+public:
+ H(unsigned);
+ H(H &&);
+ bool m_fn1();
+};
+class I {
+ void m_fn2(const int &&);
+ static H m_fn3(const int &);
+};
+template <typename Functor> void Bind(Functor);
+class J {
+public:
+ static basic_string<char> m_fn4();
+};
+int a;
+void I::m_fn2(const int &&) { Bind(m_fn3); }
+H I::m_fn3(const int &) {
+ !false ? (void)0 : G() & F() << J::m_fn4();
+ H b(a);
+ if (b.m_fn1())
+ F();
+}
Jakub
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix another ipa-split caused ICE (PR ipa/69241)
2016-02-11 9:22 ` Richard Biener
2016-02-11 16:14 ` Jakub Jelinek
@ 2016-02-11 20:17 ` Jeff Law
1 sibling, 0 replies; 5+ messages in thread
From: Jeff Law @ 2016-02-11 20:17 UTC (permalink / raw)
To: Richard Biener, Jakub Jelinek; +Cc: gcc-patches, Jan Hubicka
On 02/11/2016 02:22 AM, Richard Biener wrote:
> On Wed, 10 Feb 2016, Jakub Jelinek wrote:
>
>> Hi!
>>
>> Markus has pointed out to a reduced testcase which still ICEs even with the
>> PR69241 fix. In that case the function with TREE_ADDRESSABLE return type
>> does not return at all (and -Wreturn-type properly diagnoses it).
>> For that case the following patch just forces the lhs on the *.part.*
>> call, so that we don't ICE in assign_temp.
>>
>> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> Um... I wonder if it wouldn't be better to force such functions to
> be noreturn by say, placing a __builtin_unreachable () at the missing
> return and maybe even adjust the return type.
Remember that __builtin_unreachable doesn't actually insert any real
code, so if by some means we get to that point, we'll happily continue
executing whatever code is there, which opens a potential security hole.
I generally prefer __builtin_trap over __builtin_unreachable. The
single instruction is of marginal cost and provides a level of safety if
we do manage to get into "unreachable" code.
Jeff
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Fix another ipa-split caused ICE (PR ipa/69241)
2016-02-11 16:14 ` Jakub Jelinek
@ 2016-02-12 11:36 ` Richard Biener
0 siblings, 0 replies; 5+ messages in thread
From: Richard Biener @ 2016-02-12 11:36 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: Jan Hubicka, gcc-patches
On Thu, 11 Feb 2016, Jakub Jelinek wrote:
> On Thu, Feb 11, 2016 at 10:22:24AM +0100, Richard Biener wrote:
> > The other option is to simply not split the function in this case.
>
> Here is a better fix (but it needs the other patch I've sent, so that
> what is return_bb stays the same).
>
> This patch arranges for the case where there is return_bb, but does not
> return a value, in function that has return type TREE_ADDRESSABLE,
> to just use void return type from the split part (because we would never
> set lhs of the call to *.part.* in that case anyway).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux on top of the PR68672
> patch, ok for trunk?
Ok.
Thanks,
Richard.
> 2016-02-10 Jakub Jelinek <jakub@redhat.com>
>
> PR ipa/69241
> * ipa-split.c (split_function): If split part returns TREE_ADDRESSABLE
> type by reference, force lhs on the call.
>
> * g++.dg/ipa/pr69241-4.C: New test.
>
> --- gcc/ipa-split.c.jj 2016-02-11 12:46:15.975777652 +0100
> +++ gcc/ipa-split.c 2016-02-11 13:06:57.715241871 +0100
> @@ -629,7 +629,18 @@ consider_split (struct split_point *curr
> 4) For non-SSA we need to look where the var is computed. */
> retval = find_retval (return_bb);
> if (!retval)
> - current->split_part_set_retval = true;
> + {
> + /* If there is a return_bb with no return value in function returning
> + value by reference, also make the split part return void, otherwise
> + we expansion would try to create a non-POD temporary, which is
> + invalid. */
> + if (return_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)
> + && DECL_RESULT (current_function_decl)
> + && DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
> + current->split_part_set_retval = false;
> + else
> + current->split_part_set_retval = true;
> + }
> else if (is_gimple_min_invariant (retval))
> current->split_part_set_retval = false;
> /* Special case is value returned by reference we record as if it was non-ssa
> --- gcc/testsuite/g++.dg/ipa/pr69241-4.C.jj 2016-02-11 13:00:04.160075417 +0100
> +++ gcc/testsuite/g++.dg/ipa/pr69241-4.C 2016-02-11 13:00:04.160075417 +0100
> @@ -0,0 +1,55 @@
> +// PR ipa/69241
> +// { dg-do compile { target c++11 } }
> +// { dg-options "-O2 -Wno-return-type" }
> +
> +template <typename> class A;
> +struct B {
> + using pointer = int *;
> +};
> +template <typename _CharT, typename = A<_CharT>> class basic_string {
> + long _M_string_length;
> + enum { _S_local_capacity = 15 } _M_local_buf[_S_local_capacity];
> + B::pointer _M_local_data;
> +
> +public:
> + ~basic_string();
> +};
> +template <typename _CharT, typename _Traits, typename _Alloc>
> +int operator<<(_Traits, basic_string<_CharT, _Alloc>);
> +class C {
> + basic_string<A<char>> _M_string;
> +};
> +class D {
> + C _M_stringbuf;
> +};
> +class F {
> + int stream;
> + D stream_;
> +};
> +class G {
> +public:
> + void operator&(int);
> +};
> +class H {
> +public:
> + H(unsigned);
> + H(H &&);
> + bool m_fn1();
> +};
> +class I {
> + void m_fn2(const int &&);
> + static H m_fn3(const int &);
> +};
> +template <typename Functor> void Bind(Functor);
> +class J {
> +public:
> + static basic_string<char> m_fn4();
> +};
> +int a;
> +void I::m_fn2(const int &&) { Bind(m_fn3); }
> +H I::m_fn3(const int &) {
> + !false ? (void)0 : G() & F() << J::m_fn4();
> + H b(a);
> + if (b.m_fn1())
> + F();
> +}
>
> Jakub
>
>
--
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)
^ permalink raw reply [flat|nested] 5+ messages in thread
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2016-02-10 22:32 [PATCH] Fix another ipa-split caused ICE (PR ipa/69241) Jakub Jelinek
2016-02-11 9:22 ` Richard Biener
2016-02-11 16:14 ` Jakub Jelinek
2016-02-12 11:36 ` Richard Biener
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