libstdc++: Make _GLIBCXX_NODISCARD work for C++11 and C++14

The _GLIBCXX_NODISCARD macro only expands to [[__nodiscard__]] for C++17
and later, but all supported compilers will allow us to use that for
C++11 and C++14 too. Enable it for those older standards, to give
improved diagnostics for users of those older standards.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_NODISCARD): Expand for C++11
	and C++14.
	* testsuite/22_locale/locale/cons/12438.cc: Adjust dg-warning to
	expect nodiscard warnings for C++11 and C++14 as well.
	* testsuite/22_locale/locale/operations/2.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/1_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/2_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/3_neg.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/concept_check_1.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/2.cc: Likewise.
	* testsuite/25_algorithms/lexicographical_compare/71545.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/33613.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/irreflexive.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc: Likewise.
	* testsuite/25_algorithms/minmax/3.cc: Likewise.
	* testsuite/25_algorithms/search/78346.cc: Likewise.
	* testsuite/25_algorithms/search_n/58358.cc: Likewise.
	* testsuite/25_algorithms/unique/1.cc: Likewise.
	* testsuite/25_algorithms/unique/11480.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/33613.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc: Likewise.
	* testsuite/27_io/ios_base/types/fmtflags/bitmask_operators.cc:
	Likewise.
	* testsuite/27_io/ios_base/types/iostate/bitmask_operators.cc:
	Likewise.
	* testsuite/27_io/ios_base/types/openmode/bitmask_operators.cc:
	Likewise.
	* testsuite/ext/concept_checks.cc: Likewise.
	* testsuite/ext/is_heap/47709.cc: Likewise.
	* testsuite/ext/is_sorted/cxx0x.cc: Likewise.
This commit is contained in:
Jonathan Wakely 2024-02-26 11:40:46 +00:00 committed by Jonathan Wakely
parent c924a03ae1
commit e627a941dc
No known key found for this signature in database
27 changed files with 39 additions and 41 deletions

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@ -169,7 +169,7 @@
#endif
// Macro to warn about unused results.
#if __cplusplus >= 201703L
#if __cplusplus >= 201103L
# define _GLIBCXX_NODISCARD [[__nodiscard__]]
#else
# define _GLIBCXX_NODISCARD

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@ -45,7 +45,7 @@ void test01(int iters)
locale loc2 = locale("");
VERIFY( !has_facet<MyFacet>(loc2) );
loc1.combine<MyFacet>(loc2); // { dg-warning "nodiscard" "" { target c++17 } }
loc1.combine<MyFacet>(loc2); // { dg-warning "nodiscard" "" { target c++11 } }
VERIFY( false );
}
catch (std::runtime_error&)

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@ -48,7 +48,7 @@ void test02()
// Derivation, MF check.
locale loc_gnu(loc_c, new gnu_collate);
gnu_count = 0;
loc_gnu(s01, s02); // { dg-warning "nodiscard" "" { target c++17 } }
loc_gnu(s01, s02); // { dg-warning "nodiscard" "" { target c++11 } }
VERIFY( gnu_count == 1 );
}

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@ -27,7 +27,7 @@ test01()
std::vector<int> vect;
vect.push_back(1);
std::equal(vect.end(), vect.begin(), vect.begin());
// { dg-warning "ignoring return value" "" { target c++17 } 29 }
// { dg-warning "ignoring return value" "" { target c++11 } 29 }
}
int

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@ -27,7 +27,7 @@ test01()
std::vector<int> v1, v2;
v1.push_back(1);
std::equal(v1.begin(), v1.end(), v2.begin());
// { dg-warning "ignoring return value" "" { target c++17 } 29 }
// { dg-warning "ignoring return value" "" { target c++11 } 29 }
}
int

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@ -33,7 +33,7 @@ test01()
l2.push_back(2);
std::equal(++l1.begin(), l1.end(), ++l2.begin());
// { dg-warning "ignoring return value" "" { target c++17 } 35 }
// { dg-warning "ignoring return value" "" { target c++11 } 35 }
}
int

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@ -37,7 +37,7 @@ class2 b;
void test01()
{
std::find_first_of(&a, &a, &b, &b, comp);
// { dg-warning "ignoring return value" "" { target c++17 } 39 }
// { dg-warning "ignoring return value" "" { target c++11 } 39 }
}
int main()

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@ -103,7 +103,7 @@ void test02()
int arr[] = { 11, 22, 33 };
using namespace std;
is_permutation(begin(arr0), end(arr0), begin(arr), end(arr), thrower);
// { dg-warning "ignoring return value" "" { target c++17 } 105 }
// { dg-warning "ignoring return value" "" { target c++11 } 105 }
}
int main()

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@ -33,5 +33,5 @@ int main()
X x[1];
int i[1];
std::lexicographical_compare(x, x+1, i, i+1);
// { dg-warning "ignoring return value" "" { target c++17 } 35 }
// { dg-warning "ignoring return value" "" { target c++11 } 35 }
}

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@ -33,5 +33,5 @@ bool ab(A, B);
void test01(A* a, B b)
{
std::lower_bound(a, a, b, ab);
// { dg-warning "ignoring return value" "" { target c++17 } 35 }
// { dg-warning "ignoring return value" "" { target c++11 } 35 }
}

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@ -44,5 +44,5 @@ void test01()
{
A as[] = { 0, 1, 2, 3 };
std::lower_bound(as, as + 4, 1, A_int_comparer());
// { dg-warning "ignoring return value" "" { target c++17 } 46 }
// { dg-warning "ignoring return value" "" { target c++11 } 46 }
}

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@ -36,7 +36,7 @@ void test01()
{
A as[] = { 0, 1, 2, 0, 2, 3 };
std::lower_bound(as, as + 6, A(1));
// { dg-warning "ignoring return value" "" { target c++17 } 38 }
// { dg-warning "ignoring return value" "" { target c++11 } 38 }
}
int

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@ -24,7 +24,7 @@ void test01()
{
int as[] = { 0, 1, 0, 2, 3 };
std::lower_bound(as, as + 5, 1, std::less<int>());
// { dg-warning "ignoring return value" "" { target c++17 } 26 }
// { dg-warning "ignoring return value" "" { target c++11 } 26 }
}

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@ -43,7 +43,7 @@ int compare_counter::count = 0;
void test01()
{
std::minmax({1, 2, 3, 4, 5, 6, 7, 8}, compare_counter());
// { dg-warning "ignoring return value" "" { target c++17 } 45 }
// { dg-warning "ignoring return value" "" { target c++11 } 45 }
// If N is the number of arguments in the minmax function call,
// 25.3.7 specifies that at most 3N/2 comparisons are allowed.

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@ -109,7 +109,7 @@ test01()
{
value s[] = { 0, 1, 2, 3, 4, 5 };
std::search(s, s+6, stashing_iterator(s), stashing_iterator(s+4));
// { dg-warning "ignoring return value" "" { target c++17 } 111 }
// { dg-warning "ignoring return value" "" { target c++11 } 111 }
}
int

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@ -29,7 +29,7 @@ void test01()
int count = 0;
std::search_n(a.begin(), a.end(), 10, 1,
[&count](int t, int u) { ++count; return t == u; });
// { dg-warning "ignoring return value" "" { target c++17 } 30 }
// { dg-warning "ignoring return value" "" { target c++11 } 30 }
VERIFY( count <= 11 );
}

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@ -27,6 +27,6 @@ int main()
using namespace std;
list<int> menge;
unique (menge.begin(), menge.end());
// { dg-warning "ignoring return value" "" { target c++17 } 29 }
// { dg-warning "ignoring return value" "" { target c++11 } 29 }
return 0;
}

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@ -31,7 +31,7 @@ bool compare(int a, int b)
// libstdc++/11480
void test01()
{
std::unique(a, a+10, compare); // { dg-warning "ignoring return value" "" { target c++17 } }
std::unique(a, a+10, compare); // { dg-warning "ignoring return value" "" { target c++11 } }
VERIFY( compare_count == 9 );
}

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@ -33,5 +33,5 @@ bool ba(B, A);
void test01(A* a, B b)
{
std::upper_bound(a, a, b, ba);
// { dg-warning "ignoring return value" "" { target c++17 } 35 }
// { dg-warning "ignoring return value" "" { target c++11 } 35 }
}

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@ -36,7 +36,7 @@ void test01()
{
A as[] = { 0, 2, 1, 3, 4, 5 };
std::upper_bound(as, as + 6, A(1));
// { dg-warning "ignoring return value" "" { target c++17 } 38 }
// { dg-warning "ignoring return value" "" { target c++11 } 38 }
}
int

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@ -24,7 +24,7 @@ void test01()
{
int as[] = { 0, 2, 1, 3, 4 };
std::upper_bound(as, as + 5, 1, std::less<int>());
// { dg-warning "ignoring return value" "" { target c++17 } 26 }
// { dg-warning "ignoring return value" "" { target c++11 } 26 }
}

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@ -27,7 +27,7 @@ int main()
{
__gnu_test::bitmask_operators<std::ios_base::fmtflags>();
}
// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }

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@ -27,7 +27,7 @@ int main()
{
__gnu_test::bitmask_operators<std::ios_base::iostate>();
}
// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }

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@ -27,7 +27,7 @@ int main()
{
__gnu_test::bitmask_operators<std::ios_base::openmode>();
}
// { dg-warning "ignoring return value.*operator\\|" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++17 } 0 }
// { dg-warning "ignoring return value.*operator\\|" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator&" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator\\^" "" { target c++11 } 0 }
// { dg-warning "ignoring return value.*operator~" "" { target c++11 } 0 }

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@ -73,10 +73,10 @@ test2054( )
upper_bound(Index.begin(), Index.end(), SearchTerm, aComparison);
equal_range(Index.begin(), Index.end(), SearchTerm, aComparison);
binary_search(Index.begin(), Index.end(), SearchTerm, aComparison);
// { dg-warning "ignoring return value" "" { target c++17 } 72 }
// { dg-warning "ignoring return value" "" { target c++17 } 73 }
// { dg-warning "ignoring return value" "" { target c++17 } 74 }
// { dg-warning "ignoring return value" "" { target c++17 } 75 }
// { dg-warning "ignoring return value" "" { target c++11 } 72 }
// { dg-warning "ignoring return value" "" { target c++11 } 73 }
// { dg-warning "ignoring return value" "" { target c++11 } 74 }
// { dg-warning "ignoring return value" "" { target c++11 } 75 }
}
int main()

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@ -24,6 +24,5 @@
void foo()
{
std::vector<int> v;
is_heap(v.begin(), v.end());
// { dg-warning "ignoring return value" "" { target c++17 } 27 }
is_heap(v.begin(), v.end()); // { dg-warning "ignoring return value" }
}

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@ -23,6 +23,5 @@
void foo()
{
std::vector<int> v;
is_sorted(v.begin(), v.end());
// { dg-warning "ignoring return value" "" { target c++17 } 26 }
is_sorted(v.begin(), v.end()); // { dg-warning "ignoring return value" }
}