Thank you, sorry for the trouble. vedant
> On Sep 25, 2019, at 3:36 PM, Evgenii Stepanov <eugeni.stepa...@gmail.com> > wrote: > > FYI I've fixed a memory leak in the new test in r372925. > > On Wed, Sep 25, 2019 at 10:58 AM Vedant Kumar via cfe-commits > <cfe-commits@lists.llvm.org> wrote: >> >> Author: vedantk >> Date: Wed Sep 25 11:00:31 2019 >> New Revision: 372903 >> >> URL: http://llvm.org/viewvc/llvm-project?rev=372903&view=rev >> Log: >> [Mangle] Add flag to asm labels to disable '\01' prefixing >> >> LLDB synthesizes decls using asm labels. These decls cannot have a mangle >> different than the one specified in the label name. I.e., the '\01' prefix >> should not be added. >> >> Fixes an expression evaluation failure in lldb's TestVirtual.py on iOS. >> >> rdar://45827323 >> >> Differential Revision: https://reviews.llvm.org/D67774 >> >> Modified: >> cfe/trunk/include/clang/Basic/Attr.td >> cfe/trunk/include/clang/Basic/AttrDocs.td >> cfe/trunk/lib/AST/Mangle.cpp >> cfe/trunk/lib/Sema/SemaDecl.cpp >> cfe/trunk/unittests/AST/DeclTest.cpp >> >> Modified: cfe/trunk/include/clang/Basic/Attr.td >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=372903&r1=372902&r2=372903&view=diff >> ============================================================================== >> --- cfe/trunk/include/clang/Basic/Attr.td (original) >> +++ cfe/trunk/include/clang/Basic/Attr.td Wed Sep 25 11:00:31 2019 >> @@ -722,9 +722,25 @@ def AVRSignal : InheritableAttr, TargetS >> >> def AsmLabel : InheritableAttr { >> let Spellings = [Keyword<"asm">, Keyword<"__asm__">]; >> - let Args = [StringArgument<"Label">]; >> + let Args = [ >> + // Label specifies the mangled name for the decl. >> + StringArgument<"Label">, >> + >> + // IsLiteralLabel specifies whether the label is literal (i.e. >> suppresses >> + // the global C symbol prefix) or not. If not, the mangle-suppression >> prefix >> + // ('\01') is omitted from the decl name at the LLVM IR level. >> + // >> + // Non-literal labels are used by some external AST sources like LLDB. >> + BoolArgument<"IsLiteralLabel", /*optional=*/0, /*fake=*/1> >> + ]; >> let SemaHandler = 0; >> - let Documentation = [Undocumented]; >> + let Documentation = [AsmLabelDocs]; >> + let AdditionalMembers = >> +[{ >> +bool isEquivalent(AsmLabelAttr *Other) const { >> + return getLabel() == Other->getLabel() && getIsLiteralLabel() == >> Other->getIsLiteralLabel(); >> +} >> +}]; >> } >> >> def Availability : InheritableAttr { >> >> Modified: cfe/trunk/include/clang/Basic/AttrDocs.td >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=372903&r1=372902&r2=372903&view=diff >> ============================================================================== >> --- cfe/trunk/include/clang/Basic/AttrDocs.td (original) >> +++ cfe/trunk/include/clang/Basic/AttrDocs.td Wed Sep 25 11:00:31 2019 >> @@ -2558,6 +2558,30 @@ manipulating bits of the enumerator when >> }]; >> } >> >> +def AsmLabelDocs : Documentation { >> + let Category = DocCatDecl; >> + let Content = [{ >> +This attribute can be used on a function or variable to specify its symbol >> name. >> + >> +On some targets, all C symbols are prefixed by default with a single >> character, typically ``_``. This was done historically to distinguish them >> from symbols used by other languages. (This prefix is also added to the >> standard Itanium C++ ABI prefix on "mangled" symbol names, so that e.g. on >> such targets the true symbol name for a C++ variable declared as ``int >> cppvar;`` would be ``__Z6cppvar``; note the two underscores.) This prefix >> is *not* added to the symbol names specified by the ``asm`` attribute; >> programmers wishing to match a C symbol name must compensate for this. >> + >> +For example, consider the following C code: >> + >> +.. code-block:: c >> + >> + int var1 asm("altvar") = 1; // "altvar" in symbol table. >> + int var2 = 1; // "_var2" in symbol table. >> + >> + void func1(void) asm("altfunc"); >> + void func1(void) {} // "altfunc" in symbol table. >> + void func2(void) {} // "_func2" in symbol table. >> + >> +Clang's implementation of this attribute is compatible with GCC's, >> `documented here <https://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html>`_. >> + >> +While it is possible to use this attribute to name a special symbol used >> internally by the compiler, such as an LLVM intrinsic, this is neither >> recommended nor supported and may cause the compiler to crash or miscompile. >> Users who wish to gain access to intrinsic behavior are strongly encouraged >> to request new builtin functions. >> + }]; >> +} >> + >> def EnumExtensibilityDocs : Documentation { >> let Category = DocCatDecl; >> let Content = [{ >> >> Modified: cfe/trunk/lib/AST/Mangle.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Mangle.cpp?rev=372903&r1=372902&r2=372903&view=diff >> ============================================================================== >> --- cfe/trunk/lib/AST/Mangle.cpp (original) >> +++ cfe/trunk/lib/AST/Mangle.cpp Wed Sep 25 11:00:31 2019 >> @@ -122,15 +122,21 @@ void MangleContext::mangleName(const Nam >> if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) { >> // If we have an asm name, then we use it as the mangling. >> >> + // If the label isn't literal, or if this is an alias for an LLVM >> intrinsic, >> + // do not add a "\01" prefix. >> + if (!ALA->getIsLiteralLabel() || ALA->getLabel().startswith("llvm.")) { >> + Out << ALA->getLabel(); >> + return; >> + } >> + >> // Adding the prefix can cause problems when one file has a "foo" and >> // another has a "\01foo". That is known to happen on ELF with the >> // tricks normally used for producing aliases (PR9177). Fortunately the >> // llvm mangler on ELF is a nop, so we can just avoid adding the \01 >> - // marker. We also avoid adding the marker if this is an alias for an >> - // LLVM intrinsic. >> + // marker. >> char GlobalPrefix = >> getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix(); >> - if (GlobalPrefix && !ALA->getLabel().startswith("llvm.")) >> + if (GlobalPrefix) >> Out << '\01'; // LLVM IR Marker for __asm("foo") >> >> Out << ALA->getLabel(); >> >> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=372903&r1=372902&r2=372903&view=diff >> ============================================================================== >> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original) >> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Wed Sep 25 11:00:31 2019 >> @@ -2766,7 +2766,7 @@ void Sema::mergeDeclAttributes(NamedDecl >> >> if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) { >> if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) { >> - if (OldA->getLabel() != NewA->getLabel()) { >> + if (!OldA->isEquivalent(NewA)) { >> // This redeclaration changes __asm__ label. >> Diag(New->getLocation(), diag::err_different_asm_label); >> Diag(OldA->getLocation(), diag::note_previous_declaration); >> @@ -6983,8 +6983,8 @@ NamedDecl *Sema::ActOnVariableDeclarator >> } >> } >> >> - NewVD->addAttr(::new (Context) >> - AsmLabelAttr(Context, SE->getStrTokenLoc(0), Label)); >> + NewVD->addAttr(::new (Context) AsmLabelAttr( >> + Context, SE->getStrTokenLoc(0), Label, /*IsLiteralLabel=*/true)); >> } else if (!ExtnameUndeclaredIdentifiers.empty()) { >> llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I = >> ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier()); >> @@ -8882,8 +8882,9 @@ Sema::ActOnFunctionDeclarator(Scope *S, >> if (Expr *E = (Expr*) D.getAsmLabel()) { >> // The parser guarantees this is a string. >> StringLiteral *SE = cast<StringLiteral>(E); >> - NewFD->addAttr(::new (Context) AsmLabelAttr(Context, >> SE->getStrTokenLoc(0), >> - SE->getString())); >> + NewFD->addAttr(::new (Context) >> + AsmLabelAttr(Context, SE->getStrTokenLoc(0), >> + SE->getString(), >> /*IsLiteralLabel=*/true)); >> } else if (!ExtnameUndeclaredIdentifiers.empty()) { >> llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I = >> ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier()); >> @@ -17555,8 +17556,8 @@ void Sema::ActOnPragmaRedefineExtname(Id >> LookupOrdinaryName); >> AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc), >> AttributeCommonInfo::AS_Pragma); >> - AsmLabelAttr *Attr = >> - AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), Info); >> + AsmLabelAttr *Attr = AsmLabelAttr::CreateImplicit( >> + Context, AliasName->getName(), /*LiteralLabel=*/true, Info); >> >> // If a declaration that: >> // 1) declares a function or a variable >> >> Modified: cfe/trunk/unittests/AST/DeclTest.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/AST/DeclTest.cpp?rev=372903&r1=372902&r2=372903&view=diff >> ============================================================================== >> --- cfe/trunk/unittests/AST/DeclTest.cpp (original) >> +++ cfe/trunk/unittests/AST/DeclTest.cpp Wed Sep 25 11:00:31 2019 >> @@ -10,12 +10,16 @@ >> // >> //===----------------------------------------------------------------------===// >> >> +#include "clang/AST/ASTContext.h" >> +#include "clang/AST/Mangle.h" >> #include "clang/ASTMatchers/ASTMatchFinder.h" >> +#include "clang/Basic/LLVM.h" >> #include "clang/Tooling/Tooling.h" >> #include "gtest/gtest.h" >> >> using namespace clang::ast_matchers; >> using namespace clang::tooling; >> +using namespace clang; >> >> TEST(Decl, CleansUpAPValues) { >> MatchFinder Finder; >> @@ -56,3 +60,48 @@ TEST(Decl, CleansUpAPValues) { >> "constexpr _Complex __uint128_t c = 0xffffffffffffffff;", >> Args)); >> } >> + >> +TEST(Decl, AsmLabelAttr) { >> + // Create two method decls: `f` and `g`. >> + StringRef Code = R"( >> + struct S { >> + void f() {} >> + void g() {} >> + }; >> + )"; >> + auto AST = >> + tooling::buildASTFromCodeWithArgs(Code, {"-target", >> "i386-apple-darwin"}); >> + ASTContext &Ctx = AST->getASTContext(); >> + assert(Ctx.getTargetInfo().getDataLayout().getGlobalPrefix() && >> + "Expected target to have a global prefix"); >> + DiagnosticsEngine &Diags = AST->getDiagnostics(); >> + SourceManager &SM = AST->getSourceManager(); >> + FileID MainFileID = SM.getMainFileID(); >> + >> + // Find the method decls within the AST. >> + SmallVector<Decl *, 1> Decls; >> + AST->findFileRegionDecls(MainFileID, Code.find('{'), 0, Decls); >> + ASSERT_TRUE(Decls.size() == 1); >> + CXXRecordDecl *DeclS = cast<CXXRecordDecl>(Decls[0]); >> + NamedDecl *DeclF = *DeclS->method_begin(); >> + NamedDecl *DeclG = *(++DeclS->method_begin()); >> + >> + // Attach asm labels to the decls: one literal, and one not. >> + DeclF->addAttr(::new (Ctx) AsmLabelAttr(Ctx, SourceLocation(), "foo", >> + /*LiteralLabel=*/true)); >> + DeclG->addAttr(::new (Ctx) AsmLabelAttr(Ctx, SourceLocation(), "goo", >> + /*LiteralLabel=*/false)); >> + >> + // Mangle the decl names. >> + std::string MangleF, MangleG; >> + MangleContext *MC = ItaniumMangleContext::create(Ctx, Diags); >> + { >> + llvm::raw_string_ostream OS_F(MangleF); >> + llvm::raw_string_ostream OS_G(MangleG); >> + MC->mangleName(DeclF, OS_F); >> + MC->mangleName(DeclG, OS_G); >> + } >> + >> + ASSERT_TRUE(0 == MangleF.compare("\x01" "foo")); >> + ASSERT_TRUE(0 == MangleG.compare("goo")); >> +} >> >> >> _______________________________________________ >> cfe-commits mailing list >> cfe-commits@lists.llvm.org >> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
