* [PATCH] libstdc++: mark variables as possibly unused
@ 2020-08-24 11:26 Krystian Kuźniarek
2020-08-24 11:59 ` Jonathan Wakely
0 siblings, 1 reply; 5+ messages in thread
From: Krystian Kuźniarek @ 2020-08-24 11:26 UTC (permalink / raw)
To: gcc-patches, libstdc++
Hi,
First of all, sorry, I must have sent it as quoted-printable so spaces and
tabs are preserved.
A description of the problem/bug and how your patch addresses it:
I've got a small patch for -Wunused-variable and -Wunused-parameter in
system headers. These are needed either for:
1) __glibcxx_assert() that quickly goes away during an early compilation
step leaving the warning
2) code that conditionally is removed by preprocessor leaving the warning
Testcases:
N/A, it's only a warning.
ChangeLog:
Sorry, contrib/mklog.py didn't quite work for me.
For some reason after instruction in line 129: "diff = PatchSet(data)" my
"diff" variable is always empty.
Bootstrapping and testing:
Tested that manually by recompling GCC, unfolding all headers with
`#include <stdc++.h>` and compiling what's been included by it.
The patch itself:
diff --git a/libstdc++-v3/include/bits/atomic_base.h
b/libstdc++-v3/include/bits/atomic_base.h
index 015acef83c4..1fbb2d78d28 100644
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
clear(memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_consume);
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -242,7 +243,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
clear(memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_consume);
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -416,7 +418,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -428,7 +431,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__int_type __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -439,7 +443,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __int_type
load(memory_order __m = memory_order_seq_cst) const noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -449,7 +454,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __int_type
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -475,8 +481,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
compare_exchange_weak(__int_type& __i1, __int_type __i2,
memory_order __m1, memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -490,8 +498,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -520,8 +530,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
compare_exchange_strong(__int_type& __i1, __int_type __i2,
memory_order __m1, memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -535,8 +547,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
@@ -736,7 +750,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -749,7 +764,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -760,7 +776,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __pointer_type
load(memory_order __m = memory_order_seq_cst) const noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -770,7 +787,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __pointer_type
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__)) =
+ __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -797,8 +815,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -812,8 +832,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__)) =
+ __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__)) =
+ __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
diff --git a/libstdc++-v3/include/ext/new_allocator.h
b/libstdc++-v3/include/ext/new_allocator.h
index 131718b8b2f..2e21a98409f 100644
--- a/libstdc++-v3/include/ext/new_allocator.h
+++ b/libstdc++-v3/include/ext/new_allocator.h
@@ -117,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// __p is not permitted to be a null pointer.
void
- deallocate(_Tp* __p, size_type __t)
+ deallocate(_Tp* __p, size_type __t __attribute__ ((__unused__)))
{
#if __cpp_aligned_new
if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
Best regards,
Krystian
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] libstdc++: mark variables as possibly unused
2020-08-24 11:26 [PATCH] libstdc++: mark variables as possibly unused Krystian Kuźniarek
@ 2020-08-24 11:59 ` Jonathan Wakely
2020-08-28 6:32 ` Krystian Kuźniarek
0 siblings, 1 reply; 5+ messages in thread
From: Jonathan Wakely @ 2020-08-24 11:59 UTC (permalink / raw)
To: Krystian Kuźniarek; +Cc: gcc-patches, libstdc++
On 24/08/20 13:26 +0200, Krystian Kuźniarek via Libstdc++ wrote:
>Hi,
>
>First of all, sorry, I must have sent it as quoted-printable so spaces and
>tabs are preserved.
>
>A description of the problem/bug and how your patch addresses it:
>I've got a small patch for -Wunused-variable and -Wunused-parameter in
>system headers. These are needed either for:
>1) __glibcxx_assert() that quickly goes away during an early compilation
>step leaving the warning
>2) code that conditionally is removed by preprocessor leaving the warning
>
>Testcases:
>N/A, it's only a warning.
>
>ChangeLog:
>Sorry, contrib/mklog.py didn't quite work for me.
>For some reason after instruction in line 129: "diff = PatchSet(data)" my
>"diff" variable is always empty.
>
>Bootstrapping and testing:
>Tested that manually by recompling GCC, unfolding all headers with
>`#include <stdc++.h>` and compiling what's been included by it.
>
>The patch itself:
>
>diff --git a/libstdc++-v3/include/bits/atomic_base.h
>b/libstdc++-v3/include/bits/atomic_base.h
>index 015acef83c4..1fbb2d78d28 100644
>--- a/libstdc++-v3/include/bits/atomic_base.h
>+++ b/libstdc++-v3/include/bits/atomic_base.h
>@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE void
> clear(memory_order __m = memory_order_seq_cst) noexcept
> {
>- memory_order __b = __m & __memory_order_mask;
>+ memory_order __b __attribute__ ((__unused__)) =
Thanks for the patch.
Please put the line break before the '=' character i.e.
memory_order __b __attribute__ ((__unused__))
= __m & __memory_order_mask;
Other than that, the patch looks ok, and simple enough to not need a
copyright assignment for GCC.
A changelog entry and confirmation the testsuite still runs would be
preferred though.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] libstdc++: mark variables as possibly unused
2020-08-24 11:59 ` Jonathan Wakely
@ 2020-08-28 6:32 ` Krystian Kuźniarek
2020-08-28 6:40 ` Krystian Kuźniarek
0 siblings, 1 reply; 5+ messages in thread
From: Krystian Kuźniarek @ 2020-08-28 6:32 UTC (permalink / raw)
To: Jonathan Wakely; +Cc: gcc-patches, libstdc++
Ok, so here it is.
New diff:
diff --git a/libstdc++-v3/include/bits/atomic_base.h
b/libstdc++-v3/include/bits/atomic_base.h
index 015acef83c4..c4a763aae5c 100644
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
clear(memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_consume);
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -242,7 +243,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
clear(memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_consume);
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -416,7 +418,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE void
store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -428,7 +431,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__int_type __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -439,7 +443,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __int_type
load(memory_order __m = memory_order_seq_cst) const noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -449,7 +454,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __int_type
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -475,8 +481,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
compare_exchange_weak(__int_type& __i1, __int_type __i2,
memory_order __m1, memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -490,8 +498,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -520,8 +530,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
compare_exchange_strong(__int_type& __i1, __int_type __i2,
memory_order __m1, memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -535,8 +547,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
@@ -736,7 +750,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -749,7 +764,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_acquire);
__glibcxx_assert(__b != memory_order_acq_rel);
__glibcxx_assert(__b != memory_order_consume);
@@ -760,7 +776,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __pointer_type
load(memory_order __m = memory_order_seq_cst) const noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -770,7 +787,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __pointer_type
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
- memory_order __b = __m & __memory_order_mask;
+ memory_order __b __attribute__ ((__unused__))
+ = __m & __memory_order_mask;
__glibcxx_assert(__b != memory_order_release);
__glibcxx_assert(__b != memory_order_acq_rel);
@@ -797,8 +815,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
__glibcxx_assert(__b2 <= __b1);
@@ -812,8 +832,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m1,
memory_order __m2) volatile noexcept
{
- memory_order __b2 = __m2 & __memory_order_mask;
- memory_order __b1 = __m1 & __memory_order_mask;
+ memory_order __b2 __attribute__ ((__unused__))
+ = __m2 & __memory_order_mask;
+ memory_order __b1 __attribute__ ((__unused__))
+ = __m1 & __memory_order_mask;
__glibcxx_assert(__b2 != memory_order_release);
__glibcxx_assert(__b2 != memory_order_acq_rel);
diff --git a/libstdc++-v3/include/ext/new_allocator.h
b/libstdc++-v3/include/ext/new_allocator.h
index 131718b8b2f..2e21a98409f 100644
--- a/libstdc++-v3/include/ext/new_allocator.h
+++ b/libstdc++-v3/include/ext/new_allocator.h
@@ -117,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// __p is not permitted to be a null pointer.
void
- deallocate(_Tp* __p, size_type __t)
+ deallocate(_Tp* __p, size_type __t __attribute__ ((__unused__)))
{
#if __cpp_aligned_new
if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
Changelog entry:
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h: Fix -Wunused-variable
in system headers.
* include/ext/new_allocator.h: Fix -Wunused-parameter
in system headers.
Test suite confirmation:
All tests pass. Tested on both Manjaro and some Ubuntu 18.04 with gcc10 and
gcc8 respectively.
On Mon, 24 Aug 2020 at 13:59, Jonathan Wakely <jwakely@redhat.com> wrote:
> On 24/08/20 13:26 +0200, Krystian Kuźniarek via Libstdc++ wrote:
> >Hi,
> >
> >First of all, sorry, I must have sent it as quoted-printable so spaces and
> >tabs are preserved.
> >
> >A description of the problem/bug and how your patch addresses it:
> >I've got a small patch for -Wunused-variable and -Wunused-parameter in
> >system headers. These are needed either for:
> >1) __glibcxx_assert() that quickly goes away during an early compilation
> >step leaving the warning
> >2) code that conditionally is removed by preprocessor leaving the warning
> >
> >Testcases:
> >N/A, it's only a warning.
> >
> >ChangeLog:
> >Sorry, contrib/mklog.py didn't quite work for me.
> >For some reason after instruction in line 129: "diff = PatchSet(data)" my
> >"diff" variable is always empty.
> >
> >Bootstrapping and testing:
> >Tested that manually by recompling GCC, unfolding all headers with
> >`#include <stdc++.h>` and compiling what's been included by it.
> >
> >The patch itself:
> >
> >diff --git a/libstdc++-v3/include/bits/atomic_base.h
> >b/libstdc++-v3/include/bits/atomic_base.h
> >index 015acef83c4..1fbb2d78d28 100644
> >--- a/libstdc++-v3/include/bits/atomic_base.h
> >+++ b/libstdc++-v3/include/bits/atomic_base.h
> >@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > _GLIBCXX_ALWAYS_INLINE void
> > clear(memory_order __m = memory_order_seq_cst) noexcept
> > {
> >- memory_order __b = __m & __memory_order_mask;
> >+ memory_order __b __attribute__ ((__unused__)) =
>
> Thanks for the patch.
>
> Please put the line break before the '=' character i.e.
>
> memory_order __b __attribute__ ((__unused__))
> = __m & __memory_order_mask;
>
> Other than that, the patch looks ok, and simple enough to not need a
> copyright assignment for GCC.
>
> A changelog entry and confirmation the testsuite still runs would be
> preferred though.
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] libstdc++: mark variables as possibly unused
2020-08-28 6:32 ` Krystian Kuźniarek
@ 2020-08-28 6:40 ` Krystian Kuźniarek
2020-09-10 15:22 ` Jonathan Wakely
0 siblings, 1 reply; 5+ messages in thread
From: Krystian Kuźniarek @ 2020-08-28 6:40 UTC (permalink / raw)
To: Jonathan Wakely; +Cc: gcc-patches, libstdc++
>Test suite confirmation:
>All tests pass. Tested on both Manjaro and some Ubuntu 18.04 with gcc10
and gcc8 respectively.
Jonathan, one more thing. I hope it's what you asked for cause all I did
was:
make bootstrap
make check
On Fri, 28 Aug 2020 at 08:32, Krystian Kuźniarek <
krystian.kuzniarek@gmail.com> wrote:
> Ok, so here it is.
> New diff:
>
> diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
> index 015acef83c4..c4a763aae5c 100644
> --- a/libstdc++-v3/include/bits/atomic_base.h
> +++ b/libstdc++-v3/include/bits/atomic_base.h
> @@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE void
> clear(memory_order __m = memory_order_seq_cst) noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_consume);
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> @@ -242,7 +243,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE void
> clear(memory_order __m = memory_order_seq_cst) volatile noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_consume);
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> @@ -416,7 +418,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE void
> store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> __glibcxx_assert(__b != memory_order_consume);
> @@ -428,7 +431,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> store(__int_type __i,
> memory_order __m = memory_order_seq_cst) volatile noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> __glibcxx_assert(__b != memory_order_consume);
> @@ -439,7 +443,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE __int_type
> load(memory_order __m = memory_order_seq_cst) const noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_release);
> __glibcxx_assert(__b != memory_order_acq_rel);
>
> @@ -449,7 +454,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE __int_type
> load(memory_order __m = memory_order_seq_cst) const volatile noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_release);
> __glibcxx_assert(__b != memory_order_acq_rel);
>
> @@ -475,8 +481,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> compare_exchange_weak(__int_type& __i1, __int_type __i2,
> memory_order __m1, memory_order __m2) noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> __glibcxx_assert(__b2 <= __b1);
> @@ -490,8 +498,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> memory_order __m1,
> memory_order __m2) volatile noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> __glibcxx_assert(__b2 <= __b1);
> @@ -520,8 +530,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> compare_exchange_strong(__int_type& __i1, __int_type __i2,
> memory_order __m1, memory_order __m2) noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> __glibcxx_assert(__b2 <= __b1);
> @@ -535,8 +547,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> memory_order __m1,
> memory_order __m2) volatile noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
>
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> @@ -736,7 +750,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> store(__pointer_type __p,
> memory_order __m = memory_order_seq_cst) noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
>
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> @@ -749,7 +764,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> store(__pointer_type __p,
> memory_order __m = memory_order_seq_cst) volatile noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_acquire);
> __glibcxx_assert(__b != memory_order_acq_rel);
> __glibcxx_assert(__b != memory_order_consume);
> @@ -760,7 +776,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE __pointer_type
> load(memory_order __m = memory_order_seq_cst) const noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_release);
> __glibcxx_assert(__b != memory_order_acq_rel);
>
> @@ -770,7 +787,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _GLIBCXX_ALWAYS_INLINE __pointer_type
> load(memory_order __m = memory_order_seq_cst) const volatile noexcept
> {
> - memory_order __b = __m & __memory_order_mask;
> + memory_order __b __attribute__ ((__unused__))
> + = __m & __memory_order_mask;
> __glibcxx_assert(__b != memory_order_release);
> __glibcxx_assert(__b != memory_order_acq_rel);
>
> @@ -797,8 +815,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> memory_order __m1,
> memory_order __m2) noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> __glibcxx_assert(__b2 <= __b1);
> @@ -812,8 +832,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> memory_order __m1,
> memory_order __m2) volatile noexcept
> {
> - memory_order __b2 = __m2 & __memory_order_mask;
> - memory_order __b1 = __m1 & __memory_order_mask;
> + memory_order __b2 __attribute__ ((__unused__))
> + = __m2 & __memory_order_mask;
> + memory_order __b1 __attribute__ ((__unused__))
> + = __m1 & __memory_order_mask;
>
> __glibcxx_assert(__b2 != memory_order_release);
> __glibcxx_assert(__b2 != memory_order_acq_rel);
> diff --git a/libstdc++-v3/include/ext/new_allocator.h b/libstdc++-v3/include/ext/new_allocator.h
> index 131718b8b2f..2e21a98409f 100644
> --- a/libstdc++-v3/include/ext/new_allocator.h
> +++ b/libstdc++-v3/include/ext/new_allocator.h
> @@ -117,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
> // __p is not permitted to be a null pointer.
> void
> - deallocate(_Tp* __p, size_type __t)
> + deallocate(_Tp* __p, size_type __t __attribute__ ((__unused__)))
> {
> #if __cpp_aligned_new
> if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
>
>
> Changelog entry:
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/atomic_base.h: Fix -Wunused-variable
> in system headers.
> * include/ext/new_allocator.h: Fix -Wunused-parameter
> in system headers.
>
>
> Test suite confirmation:
> All tests pass. Tested on both Manjaro and some Ubuntu 18.04 with gcc10
> and gcc8 respectively.
>
> On Mon, 24 Aug 2020 at 13:59, Jonathan Wakely <jwakely@redhat.com> wrote:
>
>> On 24/08/20 13:26 +0200, Krystian Kuźniarek via Libstdc++ wrote:
>> >Hi,
>> >
>> >First of all, sorry, I must have sent it as quoted-printable so spaces
>> and
>> >tabs are preserved.
>> >
>> >A description of the problem/bug and how your patch addresses it:
>> >I've got a small patch for -Wunused-variable and -Wunused-parameter in
>> >system headers. These are needed either for:
>> >1) __glibcxx_assert() that quickly goes away during an early compilation
>> >step leaving the warning
>> >2) code that conditionally is removed by preprocessor leaving the warning
>> >
>> >Testcases:
>> >N/A, it's only a warning.
>> >
>> >ChangeLog:
>> >Sorry, contrib/mklog.py didn't quite work for me.
>> >For some reason after instruction in line 129: "diff = PatchSet(data)" my
>> >"diff" variable is always empty.
>> >
>> >Bootstrapping and testing:
>> >Tested that manually by recompling GCC, unfolding all headers with
>> >`#include <stdc++.h>` and compiling what's been included by it.
>> >
>> >The patch itself:
>> >
>> >diff --git a/libstdc++-v3/include/bits/atomic_base.h
>> >b/libstdc++-v3/include/bits/atomic_base.h
>> >index 015acef83c4..1fbb2d78d28 100644
>> >--- a/libstdc++-v3/include/bits/atomic_base.h
>> >+++ b/libstdc++-v3/include/bits/atomic_base.h
>> >@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> > _GLIBCXX_ALWAYS_INLINE void
>> > clear(memory_order __m = memory_order_seq_cst) noexcept
>> > {
>> >- memory_order __b = __m & __memory_order_mask;
>> >+ memory_order __b __attribute__ ((__unused__)) =
>>
>> Thanks for the patch.
>>
>> Please put the line break before the '=' character i.e.
>>
>> memory_order __b __attribute__ ((__unused__))
>> = __m & __memory_order_mask;
>>
>> Other than that, the patch looks ok, and simple enough to not need a
>> copyright assignment for GCC.
>>
>> A changelog entry and confirmation the testsuite still runs would be
>> preferred though.
>>
>>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] libstdc++: mark variables as possibly unused
2020-08-28 6:40 ` Krystian Kuźniarek
@ 2020-09-10 15:22 ` Jonathan Wakely
0 siblings, 0 replies; 5+ messages in thread
From: Jonathan Wakely @ 2020-09-10 15:22 UTC (permalink / raw)
To: Krystian Kuźniarek; +Cc: libstdc++, gcc-patches
On 28/08/20 08:40 +0200, Krystian Kuźniarek via Libstdc++ wrote:
>>Test suite confirmation:
>>All tests pass. Tested on both Manjaro and some Ubuntu 18.04 with gcc10
>and gcc8 respectively.
Thanks.
>Jonathan, one more thing. I hope it's what you asked for cause all I did
>was:
>make bootstrap
There has been no need to say "make bootstrap" for 10 years or so,
just "make" does a bootstrap.
>make check
That runs all the tests for the entire compiler. What we're interested
in is whether there are any (new) failures caused by your patch,
specifically in the libstdc++ testsuite.
N.B. This patch is less relevant now, because these variables are
always used, because the __glibcxx_assert macro now expands to a
compile-time test (as long as the compiler supports
__builtin_is_constant_evaluated(), which GCC does).
But adding the attributes anyway is harmless, so I'll go ahead and
apply this patch. Thanks again.
>On Fri, 28 Aug 2020 at 08:32, Krystian Kuźniarek <
>krystian.kuzniarek@gmail.com> wrote:
>
>> Ok, so here it is.
>> New diff:
>>
>> diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
>> index 015acef83c4..c4a763aae5c 100644
>> --- a/libstdc++-v3/include/bits/atomic_base.h
>> +++ b/libstdc++-v3/include/bits/atomic_base.h
>> @@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE void
>> clear(memory_order __m = memory_order_seq_cst) noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_consume);
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> @@ -242,7 +243,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE void
>> clear(memory_order __m = memory_order_seq_cst) volatile noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_consume);
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> @@ -416,7 +418,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE void
>> store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> __glibcxx_assert(__b != memory_order_consume);
>> @@ -428,7 +431,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> store(__int_type __i,
>> memory_order __m = memory_order_seq_cst) volatile noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> __glibcxx_assert(__b != memory_order_consume);
>> @@ -439,7 +443,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE __int_type
>> load(memory_order __m = memory_order_seq_cst) const noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_release);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>>
>> @@ -449,7 +454,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE __int_type
>> load(memory_order __m = memory_order_seq_cst) const volatile noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_release);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>>
>> @@ -475,8 +481,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> compare_exchange_weak(__int_type& __i1, __int_type __i2,
>> memory_order __m1, memory_order __m2) noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> __glibcxx_assert(__b2 <= __b1);
>> @@ -490,8 +498,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> memory_order __m1,
>> memory_order __m2) volatile noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> __glibcxx_assert(__b2 <= __b1);
>> @@ -520,8 +530,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> compare_exchange_strong(__int_type& __i1, __int_type __i2,
>> memory_order __m1, memory_order __m2) noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> __glibcxx_assert(__b2 <= __b1);
>> @@ -535,8 +547,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> memory_order __m1,
>> memory_order __m2) volatile noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>>
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> @@ -736,7 +750,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> store(__pointer_type __p,
>> memory_order __m = memory_order_seq_cst) noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>>
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> @@ -749,7 +764,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> store(__pointer_type __p,
>> memory_order __m = memory_order_seq_cst) volatile noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_acquire);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>> __glibcxx_assert(__b != memory_order_consume);
>> @@ -760,7 +776,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE __pointer_type
>> load(memory_order __m = memory_order_seq_cst) const noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_release);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>>
>> @@ -770,7 +787,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> _GLIBCXX_ALWAYS_INLINE __pointer_type
>> load(memory_order __m = memory_order_seq_cst) const volatile noexcept
>> {
>> - memory_order __b = __m & __memory_order_mask;
>> + memory_order __b __attribute__ ((__unused__))
>> + = __m & __memory_order_mask;
>> __glibcxx_assert(__b != memory_order_release);
>> __glibcxx_assert(__b != memory_order_acq_rel);
>>
>> @@ -797,8 +815,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> memory_order __m1,
>> memory_order __m2) noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> __glibcxx_assert(__b2 <= __b1);
>> @@ -812,8 +832,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> memory_order __m1,
>> memory_order __m2) volatile noexcept
>> {
>> - memory_order __b2 = __m2 & __memory_order_mask;
>> - memory_order __b1 = __m1 & __memory_order_mask;
>> + memory_order __b2 __attribute__ ((__unused__))
>> + = __m2 & __memory_order_mask;
>> + memory_order __b1 __attribute__ ((__unused__))
>> + = __m1 & __memory_order_mask;
>>
>> __glibcxx_assert(__b2 != memory_order_release);
>> __glibcxx_assert(__b2 != memory_order_acq_rel);
>> diff --git a/libstdc++-v3/include/ext/new_allocator.h b/libstdc++-v3/include/ext/new_allocator.h
>> index 131718b8b2f..2e21a98409f 100644
>> --- a/libstdc++-v3/include/ext/new_allocator.h
>> +++ b/libstdc++-v3/include/ext/new_allocator.h
>> @@ -117,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>
>> // __p is not permitted to be a null pointer.
>> void
>> - deallocate(_Tp* __p, size_type __t)
>> + deallocate(_Tp* __p, size_type __t __attribute__ ((__unused__)))
>> {
>> #if __cpp_aligned_new
>> if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
>>
>>
>> Changelog entry:
>>
>> libstdc++-v3/ChangeLog:
>>
>> * include/bits/atomic_base.h: Fix -Wunused-variable
>> in system headers.
>> * include/ext/new_allocator.h: Fix -Wunused-parameter
>> in system headers.
>>
>>
>> Test suite confirmation:
>> All tests pass. Tested on both Manjaro and some Ubuntu 18.04 with gcc10
>> and gcc8 respectively.
>>
>> On Mon, 24 Aug 2020 at 13:59, Jonathan Wakely <jwakely@redhat.com> wrote:
>>
>>> On 24/08/20 13:26 +0200, Krystian Kuźniarek via Libstdc++ wrote:
>>> >Hi,
>>> >
>>> >First of all, sorry, I must have sent it as quoted-printable so spaces
>>> and
>>> >tabs are preserved.
>>> >
>>> >A description of the problem/bug and how your patch addresses it:
>>> >I've got a small patch for -Wunused-variable and -Wunused-parameter in
>>> >system headers. These are needed either for:
>>> >1) __glibcxx_assert() that quickly goes away during an early compilation
>>> >step leaving the warning
>>> >2) code that conditionally is removed by preprocessor leaving the warning
>>> >
>>> >Testcases:
>>> >N/A, it's only a warning.
>>> >
>>> >ChangeLog:
>>> >Sorry, contrib/mklog.py didn't quite work for me.
>>> >For some reason after instruction in line 129: "diff = PatchSet(data)" my
>>> >"diff" variable is always empty.
>>> >
>>> >Bootstrapping and testing:
>>> >Tested that manually by recompling GCC, unfolding all headers with
>>> >`#include <stdc++.h>` and compiling what's been included by it.
>>> >
>>> >The patch itself:
>>> >
>>> >diff --git a/libstdc++-v3/include/bits/atomic_base.h
>>> >b/libstdc++-v3/include/bits/atomic_base.h
>>> >index 015acef83c4..1fbb2d78d28 100644
>>> >--- a/libstdc++-v3/include/bits/atomic_base.h
>>> >+++ b/libstdc++-v3/include/bits/atomic_base.h
>>> >@@ -231,7 +231,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>> > _GLIBCXX_ALWAYS_INLINE void
>>> > clear(memory_order __m = memory_order_seq_cst) noexcept
>>> > {
>>> >- memory_order __b = __m & __memory_order_mask;
>>> >+ memory_order __b __attribute__ ((__unused__)) =
>>>
>>> Thanks for the patch.
>>>
>>> Please put the line break before the '=' character i.e.
>>>
>>> memory_order __b __attribute__ ((__unused__))
>>> = __m & __memory_order_mask;
>>>
>>> Other than that, the patch looks ok, and simple enough to not need a
>>> copyright assignment for GCC.
>>>
>>> A changelog entry and confirmation the testsuite still runs would be
>>> preferred though.
>>>
>>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-09-10 15:22 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-24 11:26 [PATCH] libstdc++: mark variables as possibly unused Krystian Kuźniarek
2020-08-24 11:59 ` Jonathan Wakely
2020-08-28 6:32 ` Krystian Kuźniarek
2020-08-28 6:40 ` Krystian Kuźniarek
2020-09-10 15:22 ` Jonathan Wakely
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