Author: Nathan Sidwell Date: 2022-02-10T04:44:48-08:00 New Revision: 815446cd3e164b8be010864648d4104ad178b129
URL: https://github.com/llvm/llvm-project/commit/815446cd3e164b8be010864648d4104ad178b129 DIFF: https://github.com/llvm/llvm-project/commit/815446cd3e164b8be010864648d4104ad178b129.diff LOG: [clang][NFC] Standard substitution checking cleanup In preparing for module mangling changes I noticed some issues with the way we check for std::basic_string instantiations and friends. *) there's a single routine for std::basic_{i,o,io}stream but it is templatized on the length of the name. Really? just use a StringRef, rather than clone the entire routine just for 'basic_iostream'. *) We have a helper routine to check for char type, and call it from several places. But given all the instantiations are of the form TPL<char, Other<char> ...> we could just check the first arg is char and the later templated args are instantiating that same type. A simpler type comparison. *) Because basic_string has a third allocator parameter, it is open coded, which I found a little confusing. But otherwise it's exactly the same pattern as the iostream ones. Just tell that checker about whether there's an expected allocator argument.[*] *) We may as well return in each block of mangleStandardSubstitution once we determine it is not one of the entities of interest -- it certainly cannot be one of the other kinds of entities. FWIW this shaves about 500 bytes off the executable. [*] I suppose we could also have this routine a tri-value, with one to indicat 'it is this name, but it's not the one you're looking for', to avoid later calls trying different names? Reviewd By: ChuanqiXu Differential Revision: https://reviews.llvm.org/D119333 Added: Modified: clang/lib/AST/ItaniumMangle.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp index 2e734e2b28cdb..b15669d426bd6 100644 --- a/clang/lib/AST/ItaniumMangle.cpp +++ b/clang/lib/AST/ItaniumMangle.cpp @@ -5969,27 +5969,19 @@ bool CXXNameMangler::mangleSubstitution(uintptr_t Ptr) { return true; } -static bool isCharType(QualType T) { - if (T.isNull()) +/// Returns whether S is a template specialization of std::Name with a single +/// argument of type A. +static bool isSpecializedAs(QualType S, llvm::StringRef Name, QualType A) { + if (S.isNull()) return false; - return T->isSpecificBuiltinType(BuiltinType::Char_S) || - T->isSpecificBuiltinType(BuiltinType::Char_U); -} - -/// Returns whether a given type is a template specialization of a given name -/// with a single argument of type char. -static bool isCharSpecialization(QualType T, const char *Name) { - if (T.isNull()) - return false; - - const RecordType *RT = T->getAs<RecordType>(); + const RecordType *RT = S->getAs<RecordType>(); if (!RT) return false; const ClassTemplateSpecializationDecl *SD = dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl()); - if (!SD) + if (!SD || !SD->getIdentifier()->isStr(Name)) return false; if (!isStdNamespace(getEffectiveDeclContext(SD))) @@ -5999,26 +5991,37 @@ static bool isCharSpecialization(QualType T, const char *Name) { if (TemplateArgs.size() != 1) return false; - if (!isCharType(TemplateArgs[0].getAsType())) + if (TemplateArgs[0].getAsType() != A) return false; - return SD->getIdentifier()->getName() == Name; + return true; } -template <std::size_t StrLen> -static bool isStreamCharSpecialization(const ClassTemplateSpecializationDecl*SD, - const char (&Str)[StrLen]) { - if (!SD->getIdentifier()->isStr(Str)) +/// Returns whether SD is a template specialization std::Name<char, +/// std::char_traits<char> [, std::allocator<char>]> +/// HasAllocator controls whether the 3rd template argument is needed. +static bool isStdCharSpecialization(const ClassTemplateSpecializationDecl *SD, + llvm::StringRef Name, bool HasAllocator) { + if (!SD->getIdentifier()->isStr(Name)) return false; const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs(); - if (TemplateArgs.size() != 2) + if (TemplateArgs.size() != (HasAllocator ? 3 : 2)) return false; - if (!isCharType(TemplateArgs[0].getAsType())) + QualType A = TemplateArgs[0].getAsType(); + if (A.isNull()) + return false; + // Plain 'char' is named Char_S or Char_U depending on the target ABI. + if (!A->isSpecificBuiltinType(BuiltinType::Char_S) && + !A->isSpecificBuiltinType(BuiltinType::Char_U)) return false; - if (!isCharSpecialization(TemplateArgs[1].getAsType(), "char_traits")) + if (!isSpecializedAs(TemplateArgs[1].getAsType(), "char_traits", A)) + return false; + + if (HasAllocator && + !isSpecializedAs(TemplateArgs[2].getAsType(), "allocator", A)) return false; return true; @@ -6031,6 +6034,7 @@ bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) { Out << "St"; return true; } + return false; } if (const ClassTemplateDecl *TD = dyn_cast<ClassTemplateDecl>(ND)) { @@ -6048,6 +6052,7 @@ bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) { Out << "Sb"; return true; } + return false; } if (const ClassTemplateSpecializationDecl *SD = @@ -6058,46 +6063,34 @@ bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) { // <substitution> ::= Ss # ::std::basic_string<char, // ::std::char_traits<char>, // ::std::allocator<char> > - if (SD->getIdentifier()->isStr("basic_string")) { - const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs(); - - if (TemplateArgs.size() != 3) - return false; - - if (!isCharType(TemplateArgs[0].getAsType())) - return false; - - if (!isCharSpecialization(TemplateArgs[1].getAsType(), "char_traits")) - return false; - - if (!isCharSpecialization(TemplateArgs[2].getAsType(), "allocator")) - return false; - + if (isStdCharSpecialization(SD, "basic_string", /*HasAllocator=*/true)) { Out << "Ss"; return true; } // <substitution> ::= Si # ::std::basic_istream<char, // ::std::char_traits<char> > - if (isStreamCharSpecialization(SD, "basic_istream")) { + if (isStdCharSpecialization(SD, "basic_istream", /*HasAllocator=*/false)) { Out << "Si"; return true; } // <substitution> ::= So # ::std::basic_ostream<char, // ::std::char_traits<char> > - if (isStreamCharSpecialization(SD, "basic_ostream")) { + if (isStdCharSpecialization(SD, "basic_ostream", /*HasAllocator=*/false)) { Out << "So"; return true; } // <substitution> ::= Sd # ::std::basic_iostream<char, // ::std::char_traits<char> > - if (isStreamCharSpecialization(SD, "basic_iostream")) { + if (isStdCharSpecialization(SD, "basic_iostream", /*HasAllocator=*/false)) { Out << "Sd"; return true; } + return false; } + return false; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
