From 4c49a6c7d577ef5e731c3d22ad63f351e0296836 Mon Sep 17 00:00:00 2001 From: Steve Naroff Date: Wed, 30 Jan 2008 23:46:05 +0000 Subject: [PATCH] Hack Sema::MergeTypeDefDecl() to silently ignore duplicate typedef's in system headers files. A bizarre, non-standard hook that many compilers appear to implement (sigh:-). git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46583 91177308-0d34-0410-b5e6-96231b3b80d8 --- Sema/SemaDecl.cpp | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Sema/SemaDecl.cpp b/Sema/SemaDecl.cpp index aaa1c82021..f45b339819 100644 --- a/Sema/SemaDecl.cpp +++ b/Sema/SemaDecl.cpp @@ -21,6 +21,10 @@ #include "clang/Parse/Scope.h" #include "clang/Basic/LangOptions.h" #include "clang/Basic/TargetInfo.h" +#include "clang/Basic/SourceManager.h" +// FIXME: layering (ideally, Sema shouldn't be dependent on Lex API's) +#include "clang/Lex/Preprocessor.h" +#include "clang/Lex/HeaderSearch.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/SmallSet.h" #include "llvm/ADT/DenseSet.h" @@ -210,6 +214,22 @@ TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, ScopedDecl *OldD) { // FIXME: Verify the underlying types are equivalent! if (getLangOptions().ObjC1 && isBuiltinObjCType(New)) return Old; + + // Redeclaration of a type is a constraint violation (6.7.2.3p1). + // Apparently GCC, Intel, and Sun all silently ignore the redeclaration if + // *either* declaration is in a system header. The code below implements + // this adhoc compatibility rule. FIXME: The following code will not + // work properly when compiling ".i" files (containing preprocessed output). + SourceManager &SrcMgr = Context.getSourceManager(); + const FileEntry *OldDeclFile = SrcMgr.getFileEntryForLoc(Old->getLocation()); + const FileEntry *NewDeclFile = SrcMgr.getFileEntryForLoc(New->getLocation()); + HeaderSearch &HdrInfo = PP.getHeaderSearchInfo(); + DirectoryLookup::DirType OldDirType = HdrInfo.getFileDirFlavor(OldDeclFile); + DirectoryLookup::DirType NewDirType = HdrInfo.getFileDirFlavor(NewDeclFile); + + if (OldDirType == DirectoryLookup::ExternCSystemHeaderDir || + NewDirType == DirectoryLookup::ExternCSystemHeaderDir) + return New; // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope. // TODO: This is totally simplistic. It should handle merging functions