https://gcc.gnu.org/g:269ce3de8c49c2244a5b4aeee5c3a90a26253da1
commit r16-7338-g269ce3de8c49c2244a5b4aeee5c3a90a26253da1 Author: Jonathan Wakely <[email protected]> Date: Tue Feb 3 15:57:47 2026 +0000 libstdc++: Fix ambiguity caused by new std::source_location constructor The new constructor added for Contracts support was not explicit, so caused ambiguities when arbitrary pointers were used in contexts which could convert to std::source_location. We don't actually need a constructor, the contract_violation::location() function can just set the data member directly. libstdc++-v3/ChangeLog: * include/std/contracts (contract_violation::location): Use source_location default constructor and then set _M_impl. * include/std/source_location (source_location(const void*)): Remove constructor. * testsuite/18_support/contracts/includes.cc: Move to... * testsuite/18_support/contracts/srcloc.cc: ...here. Test for ambiguity caused by new constructor. Reviewed-by: Tomasz Kamiński <[email protected]> Diff: --- libstdc++-v3/include/std/contracts | 5 ++++- libstdc++-v3/include/std/source_location | 4 ---- .../testsuite/18_support/contracts/includes.cc | 6 ------ libstdc++-v3/testsuite/18_support/contracts/srcloc.cc | 19 +++++++++++++++++++ 4 files changed, 23 insertions(+), 11 deletions(-) diff --git a/libstdc++-v3/include/std/contracts b/libstdc++-v3/include/std/contracts index 0fd9b10247ea..c1fe54750af9 100644 --- a/libstdc++-v3/include/std/contracts +++ b/libstdc++-v3/include/std/contracts @@ -92,7 +92,10 @@ namespace contracts detection_mode mode() const noexcept { return _M_detection_mode; } const char* comment() const noexcept { return _M_comment; } std::source_location location() const noexcept { - return std::source_location (_M_src_loc_ptr); + std::source_location __loc; + __loc._M_impl + = static_cast<const source_location::__impl*>(_M_src_loc_ptr); + return __loc; } bool is_terminating () const noexcept { return _M_evaluation_semantic == std::contracts::evaluation_semantic::enforce diff --git a/libstdc++-v3/include/std/source_location b/libstdc++-v3/include/std/source_location index f773879755c9..8115e059536d 100644 --- a/libstdc++-v3/include/std/source_location +++ b/libstdc++-v3/include/std/source_location @@ -89,11 +89,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION private: const __impl* _M_impl = nullptr; - constexpr source_location (const void *__t) - : _M_impl (static_cast <const __impl*>(__t)) {} - #ifdef __glibcxx_contracts - /* To enable use of the source __impl*. */ friend class std::contracts::contract_violation; #endif }; diff --git a/libstdc++-v3/testsuite/18_support/contracts/includes.cc b/libstdc++-v3/testsuite/18_support/contracts/includes.cc deleted file mode 100644 index 91f793f1e201..000000000000 --- a/libstdc++-v3/testsuite/18_support/contracts/includes.cc +++ /dev/null @@ -1,6 +0,0 @@ -// { dg-options "-fcontracts" } -// { dg-do compile { target c++26 } } - -// We should not get errors from including this before <contracts>: -#include <source_location> -#include <contracts> diff --git a/libstdc++-v3/testsuite/18_support/contracts/srcloc.cc b/libstdc++-v3/testsuite/18_support/contracts/srcloc.cc new file mode 100644 index 000000000000..cbafa1e69bc8 --- /dev/null +++ b/libstdc++-v3/testsuite/18_support/contracts/srcloc.cc @@ -0,0 +1,19 @@ +// { dg-options "-fcontracts" } +// { dg-do compile { target c++26 } } + +// We should not get errors from including this before <contracts>: +#include <source_location> +#include <contracts> + +// There should be no private std::source_location ctor that participates in +// the calls to f below. +struct S { S(char const *); }; +void f(S); +void f(std::source_location); + +void +test01() +{ + f(""); // { dg-bogus "ambiguous" } + f({""}); // { dg-bogus "ambiguous" } +}
