https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85648
Bug ID: 85648
Summary: Name mangling using decltype omits namespace
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: demangler
Assignee: unassigned at gcc dot gnu.org
Reporter: guilherme at amadio dot org
Target Milestone: ---
The code below will yield mangled names that are inconsistent with Clang and
ICC.
---
#include <cmath>
#include <utility>
template<typename T> class vector {};
template<typename T>
auto f(vector<T> const& v, T const& x)
-> vector<decltype(std::declval<T>())> { return {}; }
template auto f(vector<float> const& v, float const& x)
-> vector<decltype(std::declval<float>())>;
template<typename T>
vector<decltype(std::sqrt(T()))>
sqrt(vector<T> const& v)
{ return {}; }
template vector<decltype(std::sqrt(float()))>
sqrt(vector<float> const&);
---
You can also see it here: https://godbolt.org/g/ZSYUEB
gcc-7.3.0 generates these mangled names:
_Z1fIfE6vectorIDTcl7declvalIT_EEEERKS0_IS1_ERKS1_
_Z4sqrtIfE6vectorIDTcl4sqrtcvT__EEEERKS0_IS1_E
which are demangled by c++filt as:
vector<decltype ((declval<float>)())> f<float>(vector<float> const&, float
const&)
vector<decltype (sqrt((float)()))> sqrt<float>(vector<float> const&)
while both clang and icc mangle the names including the namespaces:
_Z1fIfE6vectorIDTclsr3stdE7declvalIT_EEEERKS0_IS1_ERKS1_
_Z4sqrtIfE6vectorIDTclsr3stdE4sqrtcvT__EEEERKS0_IS1_E
and c++filt fails to demangle these symbols.
