Author: Raphael Isemann Date: 2021-05-26T18:27:40+02:00 New Revision: d28bc54ff44aad7b080177ef85764d7c5444f031
URL: https://github.com/llvm/llvm-project/commit/d28bc54ff44aad7b080177ef85764d7c5444f031 DIFF: https://github.com/llvm/llvm-project/commit/d28bc54ff44aad7b080177ef85764d7c5444f031.diff LOG: [lldb] Remove cache in get_demangled_name_without_arguments This function has a single-value caching based on function local static variables. This causes two problems: * There is no synchronization, so this function randomly returns the demangled name of other functions that are demangled at the same time. * The 1-element cache is not very effective (the cache rate is around 0% when running the LLDB test suite that calls this function around 30k times). I would propose just removing it. To prevent anyone else the git archeology: the static result variables were originally added as this returned a ConstString reference, but that has since been changed so that this returns by value. Reviewed By: #lldb, JDevlieghere, shafik Differential Revision: https://reviews.llvm.org/D103107 Added: Modified: lldb/source/Core/Mangled.cpp Removed: ################################################################################ diff --git a/lldb/source/Core/Mangled.cpp b/lldb/source/Core/Mangled.cpp index 3919cb440ab40..82cabc0300113 100644 --- a/lldb/source/Core/Mangled.cpp +++ b/lldb/source/Core/Mangled.cpp @@ -35,26 +35,8 @@ static inline bool cstring_is_mangled(llvm::StringRef s) { return Mangled::GetManglingScheme(s) != Mangled::eManglingSchemeNone; } -static ConstString -get_demangled_name_without_arguments(ConstString mangled, - ConstString demangled) { - // This pair is <mangled name, demangled name without function arguments> - static std::pair<ConstString, ConstString> - g_most_recent_mangled_to_name_sans_args; - - // Need to have the mangled & demangled names we're currently examining as - // statics so we can return a const ref to them at the end of the func if we - // don't have anything better. - static ConstString g_last_mangled; - static ConstString g_last_demangled; - - if (mangled && g_most_recent_mangled_to_name_sans_args.first == mangled) { - return g_most_recent_mangled_to_name_sans_args.second; - } - - g_last_demangled = demangled; - g_last_mangled = mangled; - +static ConstString GetDemangledNameWithoutArguments(ConstString mangled, + ConstString demangled) { const char *mangled_name_cstr = mangled.GetCString(); if (demangled && mangled_name_cstr && mangled_name_cstr[0]) { @@ -73,17 +55,13 @@ get_demangled_name_without_arguments(ConstString mangled, if (!cxx_method.GetContext().empty()) shortname = cxx_method.GetContext().str() + "::"; shortname += cxx_method.GetBasename().str(); - ConstString result(shortname.c_str()); - g_most_recent_mangled_to_name_sans_args.first = mangled; - g_most_recent_mangled_to_name_sans_args.second = result; - return g_most_recent_mangled_to_name_sans_args.second; + return ConstString(shortname); } } } - if (demangled) - return g_last_demangled; - return g_last_mangled; + return demangled; + return mangled; } #pragma mark Mangled @@ -347,7 +325,7 @@ ConstString Mangled::GetName(Mangled::NamePreference preference) const { ConstString demangled = GetDemangledName(); if (preference == ePreferDemangledWithoutArguments) { - return get_demangled_name_without_arguments(m_mangled, demangled); + return GetDemangledNameWithoutArguments(m_mangled, demangled); } if (preference == ePreferDemangled) { // Call the accessor to make sure we get a demangled name in case it hasn't _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
