This breaks check-clang-tools http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/12310/steps/test/logs/stdio
On Fri, Sep 22, 2017 at 3:21 PM, Richard Smith via cfe-commits < cfe-commits@lists.llvm.org> wrote: > Author: rsmith > Date: Fri Sep 22 15:21:44 2017 > New Revision: 314037 > > URL: http://llvm.org/viewvc/llvm-project?rev=314037&view=rev > Log: > DR1113: anonymous namespaces formally give their contents internal linkage. > > This doesn't affect our code generation in any material way -- we already > give > such declarations internal linkage from a codegen perspective -- but it has > some subtle effects on code validity. > > We suppress the 'L' (internal linkage) marker for mangled names in > anonymous > namespaces, because it is redundant (the information is already carried by > the > namespace); this deviates from GCC's behavior if a variable or function in > an > anonymous namespace is redundantly declared 'static' (where GCC does > include > the 'L'), but GCC's behavior is incoherent because such a declaration can > be > validly declared with or without the 'static'. > > We still deviate from the standard in one regard here: extern "C" > declarations > in anonymous namespaces are still granted external linkage. Changing those > does > not appear to have been an intentional consequence of the standard change > in > DR1113. > > Added: > cfe/trunk/test/CXX/drs/dr11xx.cpp > Modified: > cfe/trunk/lib/AST/Decl.cpp > cfe/trunk/lib/AST/ItaniumMangle.cpp > cfe/trunk/test/CXX/basic/basic.link/p8.cpp > cfe/trunk/test/CodeGenCXX/anonymous-namespaces.cpp > cfe/trunk/test/SemaCXX/linkage2.cpp > cfe/trunk/test/SemaCXX/undefined-internal.cpp > > Modified: cfe/trunk/lib/AST/Decl.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ > Decl.cpp?rev=314037&r1=314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/lib/AST/Decl.cpp (original) > +++ cfe/trunk/lib/AST/Decl.cpp Fri Sep 22 15:21:44 2017 > @@ -619,16 +619,16 @@ LinkageComputer::getLVForNamespaceScopeD > if (D->isInAnonymousNamespace()) { > const auto *Var = dyn_cast<VarDecl>(D); > const auto *Func = dyn_cast<FunctionDecl>(D); > - // FIXME: In C++11 onwards, anonymous namespaces should give decls > - // within them (including those inside extern "C" contexts) internal > - // linkage, not unique external linkage: > + // FIXME: The check for extern "C" here is not justified by the > standard > + // wording, but we retain it from the pre-DR1113 model to avoid > breaking > + // code. > // > // C++11 [basic.link]p4: > // An unnamed namespace or a namespace declared directly or > indirectly > // within an unnamed namespace has internal linkage. > if ((!Var || !isFirstInExternCContext(Var)) && > (!Func || !isFirstInExternCContext(Func))) > - return LinkageInfo::uniqueExternal(); > + return getInternalLinkageFor(D); > } > > // Set up the defaults. > @@ -1130,7 +1130,7 @@ LinkageInfo LinkageComputer::getLVForLoc > if (const auto *Function = dyn_cast<FunctionDecl>(D)) { > if (Function->isInAnonymousNamespace() && > !Function->isInExternCContext()) > - return LinkageInfo::uniqueExternal(); > + return getInternalLinkageFor(Function); > > // This is a "void f();" which got merged with a file static. > if (Function->getCanonicalDecl()->getStorageClass() == SC_Static) > @@ -1153,7 +1153,7 @@ LinkageInfo LinkageComputer::getLVForLoc > if (const auto *Var = dyn_cast<VarDecl>(D)) { > if (Var->hasExternalStorage()) { > if (Var->isInAnonymousNamespace() && !Var->isInExternCContext()) > - return LinkageInfo::uniqueExternal(); > + return getInternalLinkageFor(Var); > > LinkageInfo LV; > if (Var->getStorageClass() == SC_PrivateExtern) > > Modified: cfe/trunk/lib/AST/ItaniumMangle.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ > ItaniumMangle.cpp?rev=314037&r1=314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/lib/AST/ItaniumMangle.cpp (original) > +++ cfe/trunk/lib/AST/ItaniumMangle.cpp Fri Sep 22 15:21:44 2017 > @@ -1287,9 +1287,15 @@ void CXXNameMangler::mangleUnqualifiedNa > // > // void test() { extern void foo(); } > // static void foo(); > + // > + // Don't bother with the L marker for names in anonymous > namespaces; the > + // 12_GLOBAL__N_1 mangling is quite sufficient there, and this > better > + // matches GCC anyway, because GCC does not treat anonymous > namespaces as > + // implying internal linkage. > if (ND && ND->getFormalLinkage() == InternalLinkage && > !ND->isExternallyVisible() && > - getEffectiveDeclContext(ND)->isFileContext()) > + getEffectiveDeclContext(ND)->isFileContext() && > + !ND->isInAnonymousNamespace()) > Out << 'L'; > > auto *FD = dyn_cast<FunctionDecl>(ND); > > Modified: cfe/trunk/test/CXX/basic/basic.link/p8.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/ > basic/basic.link/p8.cpp?rev=314037&r1=314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/test/CXX/basic/basic.link/p8.cpp (original) > +++ cfe/trunk/test/CXX/basic/basic.link/p8.cpp Fri Sep 22 15:21:44 2017 > @@ -52,6 +52,13 @@ void use_visible_no_linkage() { > visible_no_linkage3(); // expected-note {{used here}} > } > > +namespace { > + struct InternalLinkage {}; > +} > +InternalLinkage internal_linkage(); // expected-error {{used but not > defined}} > +void use_internal_linkage() { > + internal_linkage(); // expected-note {{used here}} > +} > > extern inline int not_defined; // expected-error {{not defined}} > extern inline int defined_after_use; > > Added: cfe/trunk/test/CXX/drs/dr11xx.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/ > drs/dr11xx.cpp?rev=314037&view=auto > ============================================================ > ================== > --- cfe/trunk/test/CXX/drs/dr11xx.cpp (added) > +++ cfe/trunk/test/CXX/drs/dr11xx.cpp Fri Sep 22 15:21:44 2017 > @@ -0,0 +1,30 @@ > +// RUN: %clang_cc1 -std=c++98 %s -verify -fexceptions -fcxx-exceptions > -pedantic-errors > +// RUN: %clang_cc1 -std=c++11 %s -verify -fexceptions -fcxx-exceptions > -pedantic-errors > +// RUN: %clang_cc1 -std=c++14 %s -verify -fexceptions -fcxx-exceptions > -pedantic-errors > +// RUN: %clang_cc1 -std=c++17 %s -verify -fexceptions -fcxx-exceptions > -pedantic-errors > +// RUN: %clang_cc1 -std=c++2a %s -verify -fexceptions -fcxx-exceptions > -pedantic-errors > + > +namespace dr1113 { // dr1113: partial > + namespace named { > + extern int a; // expected-note {{previous}} > + static int a; // expected-error {{static declaration of 'a' follows > non-static}} > + } > + namespace { > + extern int a; > + static int a; // ok, both declarations have internal linkage > + int b = a; > + } > + > + // FIXME: Per DR1113 and DR4, this is ill-formed due to ambiguity: the > second > + // 'f' has internal linkage, and so does not have C language linkage, > so is > + // not a redeclaration of the first 'f'. > + // > + // To avoid a breaking change here, Clang ignores the "internal > linkage" effect > + // of anonymous namespaces on declarations declared within an 'extern > "C"' > + // linkage-specification. > + extern "C" void f(); > + namespace { > + extern "C" void f(); > + } > + void g() { f(); } > +} > > Modified: cfe/trunk/test/CodeGenCXX/anonymous-namespaces.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/ > CodeGenCXX/anonymous-namespaces.cpp?rev=314037&r1= > 314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/test/CodeGenCXX/anonymous-namespaces.cpp (original) > +++ cfe/trunk/test/CodeGenCXX/anonymous-namespaces.cpp Fri Sep 22 > 15:21:44 2017 > @@ -6,7 +6,8 @@ int f(); > > namespace { > // CHECK-1: @_ZN12_GLOBAL__N_11bE = internal global i32 0 > - // CHECK-1: @_ZN12_GLOBAL__N_1L1cE = internal global i32 0 > + // CHECK-1: @_ZN12_GLOBAL__N_11cE = internal global i32 0 > + // CHECK-1: @_ZN12_GLOBAL__N_12c2E = internal global i32 0 > // CHECK-1: @_ZN12_GLOBAL__N_11D1dE = internal global i32 0 > // CHECK-1: @_ZN12_GLOBAL__N_11aE = internal global i32 0 > int a = 0; > @@ -15,6 +16,12 @@ namespace { > > static int c = f(); > > + // Note, we can't use an 'L' mangling for c or c2 (like GCC does) based > on > + // the 'static' specifier, because the variable can be redeclared > without it. > + extern int c2; > + int g() { return c2; } > + static int c2 = f(); > + > class D { > static int d; > }; > > Modified: cfe/trunk/test/SemaCXX/linkage2.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/ > SemaCXX/linkage2.cpp?rev=314037&r1=314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/test/SemaCXX/linkage2.cpp (original) > +++ cfe/trunk/test/SemaCXX/linkage2.cpp Fri Sep 22 15:21:44 2017 > @@ -143,9 +143,10 @@ namespace test13 { > } > > namespace test14 { > + // Anonymous namespace implies internal linkage, so 'static' has no > effect. > namespace { > - void a(void); // expected-note {{previous declaration is here}} > - static void a(void) {} // expected-error {{static declaration of 'a' > follows non-static declaration}} > + void a(void); > + static void a(void) {} > } > } > > > Modified: cfe/trunk/test/SemaCXX/undefined-internal.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/ > SemaCXX/undefined-internal.cpp?rev=314037&r1=314036&r2=314037&view=diff > ============================================================ > ================== > --- cfe/trunk/test/SemaCXX/undefined-internal.cpp (original) > +++ cfe/trunk/test/SemaCXX/undefined-internal.cpp Fri Sep 22 15:21:44 2017 > @@ -187,6 +187,10 @@ namespace OverloadUse { > void f(); > void f(int); // expected-warning {{function 'OverloadUse::(anonymous > namespace)::f' has internal linkage but is not defined}} > void f(int, int); // expected-warning {{function > 'OverloadUse::(anonymous namespace)::f' has internal linkage but is not > defined}} > +#if __cplusplus < 201103L > + // expected-note@-3 {{here}} > + // expected-note@-3 {{here}} > +#endif > } > template<void x()> void t() { x(); } > template<void x(int)> void t(int*) { x(10); } > @@ -194,6 +198,10 @@ namespace OverloadUse { > void g(int n) { > t<f>(&n); // expected-note {{used here}} > t<f>(&n, &n); // expected-note {{used here}} > +#if __cplusplus < 201103L > + // expected-warning@-3 {{non-type template argument referring to > function 'f' with internal linkage}} > + // expected-warning@-3 {{non-type template argument referring to > function 'f' with internal linkage}} > +#endif > } > } > > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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