Erik Schwiebert requested it, since apparently it makes it significantly easier for him to port code over to Clang from MSVC. I figured it would be OK since before this change using selectany would lead to link errors, so this should strictly fix code. I forgot to think about the code drift between 3.3 and TOT.
On Tue, May 21, 2013 at 1:39 PM, Richard Smith <[email protected]>wrote: > Why was this change merged to the branch at all? > > On Tue, May 21, 2013 at 5:00 AM, NAKAMURA Takumi <[email protected]>wrote: > >> Bill and Reid, it depends on r181677 and r182096. release_33 has been >> broken. >> >> SemaDeclAttr.cpp: In function ‘void handleSelectAnyAttr(clang::Sema&, >> clang::Decl*, const clang::AttributeList&)’: >> SemaDeclAttr.cpp:4687:33: error: ‘checkMicrosoftExt’ was not declared >> in this scope >> >> SemaDecl.cpp: In function ‘void >> checkAttributesAfterMerging(clang::Sema&, clang::NamedDecl&)’: >> SemaDecl.cpp:4645:38: error: ‘class clang::NamedDecl’ has no member >> named ‘isExternallyVisible’ >> >> ...Takumi >> >> >> 2013/5/21 Bill Wendling <[email protected]>: >> > Author: void >> > Date: Mon May 20 19:06:11 2013 >> > New Revision: 182337 >> > >> > URL: http://llvm.org/viewvc/llvm-project?rev=182337&view=rev >> > Log: >> > Merging r182266: >> > ------------------------------------------------------------------------ >> > r182266 | rnk | 2013-05-20 07:02:37 -0700 (Mon, 20 May 2013) | 13 lines >> > >> > Implement __declspec(selectany) under -fms-extensions >> > >> > selectany only applies to externally visible global variables. It has >> > the effect of making the data weak_odr. >> > >> > The MSDN docs suggest that unused definitions can only be dropped at >> > linktime, so Clang uses weak instead of linkonce. MSVC optimizes away >> > references to constant selectany data, so it must assume that there is >> > only one definition, hence weak_odr. >> > >> > Reviewers: espindola >> > >> > Differential Revision: http://llvm-reviews.chandlerc.com/D814 >> > ------------------------------------------------------------------------ >> > >> > Added: >> > cfe/branches/release_33/test/SemaCXX/attr-selectany.cpp >> > - copied unchanged from r182266, >> cfe/trunk/test/SemaCXX/attr-selectany.cpp >> > Modified: >> > cfe/branches/release_33/ (props changed) >> > cfe/branches/release_33/include/clang/Basic/Attr.td >> > cfe/branches/release_33/include/clang/Basic/DiagnosticSemaKinds.td >> > cfe/branches/release_33/lib/CodeGen/CodeGenModule.cpp >> > cfe/branches/release_33/lib/Sema/SemaDecl.cpp >> > cfe/branches/release_33/lib/Sema/SemaDeclAttr.cpp >> > cfe/branches/release_33/test/CodeGen/ms-declspecs.c >> > >> > Propchange: cfe/branches/release_33/ >> > >> ------------------------------------------------------------------------------ >> > --- svn:mergeinfo (original) >> > +++ svn:mergeinfo Mon May 20 19:06:11 2013 >> > @@ -1,4 +1,4 @@ >> > /cfe/branches/type-system-rewrite:134693-134817 >> > -/cfe/trunk:181286,181299,181368,181465,181728,181750,181909,182072 >> > >> +/cfe/trunk:181286,181299,181368,181465,181728,181750,181909,182072,182266 >> > /cfe/trunk/test:170344 >> > /cfe/trunk/test/SemaTemplate:126920 >> > >> > Modified: cfe/branches/release_33/include/clang/Basic/Attr.td >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/include/clang/Basic/Attr.td?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/include/clang/Basic/Attr.td (original) >> > +++ cfe/branches/release_33/include/clang/Basic/Attr.td Mon May 20 >> 19:06:11 2013 >> > @@ -948,6 +948,10 @@ def ForceInline : InheritableAttr { >> > let Spellings = [Keyword<"__forceinline">]; >> > } >> > >> > +def SelectAny : InheritableAttr { >> > + let Spellings = [Declspec<"selectany">]; >> > +} >> > + >> > def Win64 : InheritableAttr { >> > let Spellings = [Keyword<"__w64">]; >> > } >> > >> > Modified: >> cfe/branches/release_33/include/clang/Basic/DiagnosticSemaKinds.td >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/include/clang/Basic/DiagnosticSemaKinds.td?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/include/clang/Basic/DiagnosticSemaKinds.td >> (original) >> > +++ cfe/branches/release_33/include/clang/Basic/DiagnosticSemaKinds.td >> Mon May 20 19:06:11 2013 >> > @@ -1948,6 +1948,8 @@ def warn_weak_identifier_undeclared : Wa >> > "weak identifier %0 never declared">; >> > def err_attribute_weak_static : Error< >> > "weak declaration cannot have internal linkage">; >> > +def err_attribute_selectany_non_extern_data : Error< >> > + "'selectany' can only be applied to data items with external >> linkage">; >> > def warn_attribute_weak_import_invalid_on_definition : Warning< >> > "'weak_import' attribute cannot be specified on a definition">, >> > InGroup<IgnoredAttributes>; >> > >> > Modified: cfe/branches/release_33/lib/CodeGen/CodeGenModule.cpp >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/lib/CodeGen/CodeGenModule.cpp?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/lib/CodeGen/CodeGenModule.cpp (original) >> > +++ cfe/branches/release_33/lib/CodeGen/CodeGenModule.cpp Mon May 20 >> 19:06:11 2013 >> > @@ -1900,7 +1900,13 @@ CodeGenModule::GetLLVMLinkageVarDefiniti >> > return llvm::Function::DLLImportLinkage; >> > else if (D->hasAttr<DLLExportAttr>()) >> > return llvm::Function::DLLExportLinkage; >> > - else if (D->hasAttr<WeakAttr>()) { >> > + else if (D->hasAttr<SelectAnyAttr>()) { >> > + // selectany symbols are externally visible, so use weak instead of >> > + // linkonce. MSVC optimizes away references to const selectany >> globals, so >> > + // all definitions should be the same and ODR linkage should be >> used. >> > + // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx >> > + return llvm::GlobalVariable::WeakODRLinkage; >> > + } else if (D->hasAttr<WeakAttr>()) { >> > if (GV->isConstant()) >> > return llvm::GlobalVariable::WeakODRLinkage; >> > else >> > >> > Modified: cfe/branches/release_33/lib/Sema/SemaDecl.cpp >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/lib/Sema/SemaDecl.cpp?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/lib/Sema/SemaDecl.cpp (original) >> > +++ cfe/branches/release_33/lib/Sema/SemaDecl.cpp Mon May 20 19:06:11 >> 2013 >> > @@ -4638,6 +4638,15 @@ static void checkAttributesAfterMerging( >> > ND.dropAttr<WeakRefAttr>(); >> > } >> > } >> > + >> > + // 'selectany' only applies to externally visible varable >> declarations. >> > + // It does not apply to functions. >> > + if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) { >> > + if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) { >> > + S.Diag(Attr->getLocation(), >> diag::err_attribute_selectany_non_extern_data); >> > + ND.dropAttr<SelectAnyAttr>(); >> > + } >> > + } >> > } >> > >> > /// Given that we are within the definition of the given function, >> > >> > Modified: cfe/branches/release_33/lib/Sema/SemaDeclAttr.cpp >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/lib/Sema/SemaDeclAttr.cpp?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/lib/Sema/SemaDeclAttr.cpp (original) >> > +++ cfe/branches/release_33/lib/Sema/SemaDeclAttr.cpp Mon May 20 >> 19:06:11 2013 >> > @@ -4683,6 +4683,16 @@ static void handleForceInlineAttr(Sema & >> > S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << >> Attr.getName(); >> > } >> > >> > +static void handleSelectAnyAttr(Sema &S, Decl *D, const AttributeList >> &Attr) { >> > + if (!checkMicrosoftExt(S, Attr)) >> > + return; >> > + // Check linkage after possibly merging declaratinos. See >> > + // checkAttributesAfterMerging(). >> > + D->addAttr(::new (S.Context) >> > + SelectAnyAttr(Attr.getRange(), S.Context, >> > + Attr.getAttributeSpellingListIndex())); >> > +} >> > + >> > >> >> //===----------------------------------------------------------------------===// >> > // Top Level Sema Entry Points >> > >> >> //===----------------------------------------------------------------------===// >> > @@ -4909,6 +4919,9 @@ static void ProcessInheritableDeclAttr(S >> > case AttributeList::AT_ForceInline: >> > handleForceInlineAttr(S, D, Attr); >> > break; >> > + case AttributeList::AT_SelectAny: >> > + handleSelectAnyAttr(S, D, Attr); >> > + break; >> > >> > // Thread safety attributes: >> > case AttributeList::AT_GuardedVar: >> > >> > Modified: cfe/branches/release_33/test/CodeGen/ms-declspecs.c >> > URL: >> http://llvm.org/viewvc/llvm-project/cfe/branches/release_33/test/CodeGen/ms-declspecs.c?rev=182337&r1=182336&r2=182337&view=diff >> > >> ============================================================================== >> > --- cfe/branches/release_33/test/CodeGen/ms-declspecs.c (original) >> > +++ cfe/branches/release_33/test/CodeGen/ms-declspecs.c Mon May 20 >> 19:06:11 2013 >> > @@ -1,5 +1,10 @@ >> > // RUN: %clang_cc1 -triple i386-pc-win32 %s -emit-llvm >> -fms-compatibility -o - | FileCheck %s >> > >> > +__declspec(selectany) int x1 = 1; >> > +const __declspec(selectany) int x2 = 2; >> > +// CHECK: @x1 = weak_odr global i32 1, align 4 >> > +// CHECK: @x2 = weak_odr constant i32 2, align 4 >> > + >> > struct __declspec(align(16)) S { >> > char x; >> > }; >> > >> > >> > _______________________________________________ >> > llvm-branch-commits mailing list >> > [email protected] >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-branch-commits >> >> _______________________________________________ >> cfe-commits mailing list >> [email protected] >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >> > >
_______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
