fmtlib/fmt
1
0
Fork 1
mirror of https://github.com/fmtlib/fmt.git synced 2025-11-25 03:39:56 +01:00
Code Issues Packages Projects Releases Wiki Activity

write_demangled_name supports libc++ + clang-cl (#4560)

Browse Source 
The current implementation assumes whenever we're on an FMT_MSC_VERSION
compiler, the standard library is MSVC's STL. However, with clang-cl we
have the possibility of using LLVM libc++ instead of MSVC STL. In that
scenario, the previous implementation produced the wrong demangled names
for RTTI types.

This patch detects the different combinations, and combines the existing
demangling implementations to produce the correct names and make all
tests pass on libc++ + clang-cl.
This commit is contained in:
Fatih BAKIR
2025-10-08 12:23:57 -07:00
committed by GitHub
parent 47a18b2fe9
commit 03c7e28965
1 changed files with 62 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
include/fmt/std.h
View File

@@ -139,19 +139,8 @@ template <typename Variant, typename Char> class is_variant_formattable {
#endif // FMT_CPP_LIB_VARIANT
#if FMT_USE_RTTI
template <typename OutputIt>
auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
# ifdef FMT_HAS_ABI_CXA_DEMANGLE
int status = 0;
size_t size = 0;
std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
string_view demangled_name_view;
if (demangled_name_ptr) {
demangled_name_view = demangled_name_ptr.get();
string_view normalize_libcxx_inline_namespaces(string_view demangled_name_view,
char* begin) {
// Normalization of stdlib inline namespace names.
// libc++ inline namespaces.
// std::__1::* -> std::*
@@ -160,13 +149,12 @@ auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
// std::__cxx11::* -> std::*
// std::filesystem::__cxx11::* -> std::filesystem::*
if (demangled_name_view.starts_with("std::")) {
char* begin = demangled_name_ptr.get();
char* to = begin + 5; // std::
for (char *from = to, *end = begin + demangled_name_view.size();
for (const char *from = to, *end = begin + demangled_name_view.size();
from < end;) {
// This is safe, because demangled_name is NUL-terminated.
if (from[0] == '_' && from[1] == '_') {
char* next = from + 1;
const char* next = from + 1;
while (next < end && *next != ':') next++;
if (next[0] == ':' && next[1] == ':') {
from = next + 2;
@@ -177,12 +165,13 @@ auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
}
demangled_name_view = {begin, detail::to_unsigned(to - begin)};
}
} else {
demangled_name_view = string_view(ti.name());
}
return detail::write_bytes<char>(out, demangled_name_view);
# elif FMT_MSC_VERSION
const string_view demangled_name(ti.name());
return demangled_name_view;
}
template <class OutputIt>
auto normalize_msvc_abi_name(string_view abi_name_view, OutputIt out)
-> OutputIt {
const string_view demangled_name(abi_name_view);
for (size_t i = 0; i < demangled_name.size(); ++i) {
auto sub = demangled_name;
sub.remove_prefix(i);
@@ -201,6 +190,39 @@ auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
if (*sub.begin() != ' ') *out++ = *sub.begin();
}
return out;
}
template <typename OutputIt>
auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
# ifdef FMT_HAS_ABI_CXA_DEMANGLE
int status = 0;
size_t size = 0;
std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
string_view demangled_name_view;
if (demangled_name_ptr) {
demangled_name_view = normalize_libcxx_inline_namespaces(
demangled_name_ptr.get(), demangled_name_ptr.get());
} else {
demangled_name_view = string_view(ti.name());
}
return detail::write_bytes<char>(out, demangled_name_view);
# elif FMT_MSC_VERSION && defined(_MSVC_STL_UPDATE)
return normalize_msvc_abi_name(ti.name(), out);
# elif FMT_MSC_VERSION && defined(_LIBCPP_VERSION)
const string_view demangled_name(ti.name());
std::string name_copy(demangled_name.size(), '\0');
// normalize_msvc_abi_name removes class, struct, union etc that MSVC has in
// front of types
name_copy.erase(normalize_msvc_abi_name(demangled_name, name_copy.begin()),
name_copy.end());
// normalize_libcxx_inline_namespaces removes the inline __1, __2, etc
// namespaces libc++ uses for ABI versioning On MSVC ABI + libc++
// environments, we need to eliminate both of them.
const string_view normalized_name =
normalize_libcxx_inline_namespaces(name_copy, name_copy.data());
return detail::write_bytes<char>(out, normalized_name);
# else
return detail::write_bytes<char>(out, string_view(ti.name()));
# endif