Fix evaluation of `__has_include_next` during -frewrite-includes.

`__has_include_next` requires correct DirectoryLookup for being
evaluated correctly. We were using Preprocessor::GetCurDirLookup() but
we were calling it after the preprocessor finished its work. And in this
case CurDirLookup is always nullptr which makes `__has_include_next`
behave as `__has_include`.

Fix by storing and using CurDirLookup when preprocessor enters a file,
not when we rewrite the includes.

rdar://problem/36305026

Reviewers: bkramer

Reviewed By: bkramer

Subscribers: jkorous-apple, cfe-commits

Differential Revision: https://reviews.llvm.org/D45603

llvm-svn: 330041

1 files changed, 18 insertions, 14 deletions

diff --git a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
index e0477069b34..3b8d792e3af 100644
--- a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -32,8 +32,10 @@ class InclusionRewriter : public PPCallbacks {
   struct IncludedFile {
     FileID Id;
     SrcMgr::CharacteristicKind FileType;
-    IncludedFile(FileID Id, SrcMgr::CharacteristicKind FileType)
-        : Id(Id), FileType(FileType) {}
+    const DirectoryLookup *DirLookup;
+    IncludedFile(FileID Id, SrcMgr::CharacteristicKind FileType,
+                 const DirectoryLookup *DirLookup)
+        : Id(Id), FileType(FileType), DirLookup(DirLookup) {}
   };
   Preprocessor &PP; ///< Used to find inclusion directives.
   SourceManager &SM; ///< Used to read and manage source files.
@@ -54,7 +56,8 @@ class InclusionRewriter : public PPCallbacks {
 public:
   InclusionRewriter(Preprocessor &PP, raw_ostream &OS, bool ShowLineMarkers,
                     bool UseLineDirectives);
-  void Process(FileID FileId, SrcMgr::CharacteristicKind FileType);
+  void Process(FileID FileId, SrcMgr::CharacteristicKind FileType,
+               const DirectoryLookup *DirLookup);
   void setPredefinesBuffer(const llvm::MemoryBuffer *Buf) {
     PredefinesBuffer = Buf;
   }
@@ -156,8 +159,9 @@ void InclusionRewriter::FileChanged(SourceLocation Loc,
     // we didn't reach this file (eg: the main file) via an inclusion directive
     return;
   FileID Id = FullSourceLoc(Loc, SM).getFileID();
-  auto P = FileIncludes.insert(std::make_pair(
-      LastInclusionLocation.getRawEncoding(), IncludedFile(Id, NewFileType)));
+  auto P = FileIncludes.insert(
+      std::make_pair(LastInclusionLocation.getRawEncoding(),
+                     IncludedFile(Id, NewFileType, PP.GetCurDirLookup())));
   (void)P;
   assert(P.second && "Unexpected revisitation of the same include directive");
   LastInclusionLocation = SourceLocation();
@@ -408,7 +412,7 @@ bool InclusionRewriter::HandleHasInclude(
   Includers.push_back(std::make_pair(FileEnt, FileEnt->getDir()));
   // FIXME: Why don't we call PP.LookupFile here?
   const FileEntry *File = PP.getHeaderSearchInfo().LookupFile(
-      Filename, SourceLocation(), isAngled, nullptr, CurDir, Includers, nullptr,
+      Filename, SourceLocation(), isAngled, Lookup, CurDir, Includers, nullptr,
       nullptr, nullptr, nullptr, nullptr);
 
   FileExists = File != nullptr;
@@ -418,7 +422,8 @@ bool InclusionRewriter::HandleHasInclude(
 /// Use a raw lexer to analyze \p FileId, incrementally copying parts of it
 /// and including content of included files recursively.
 void InclusionRewriter::Process(FileID FileId,
-                                SrcMgr::CharacteristicKind FileType) {
+                                SrcMgr::CharacteristicKind FileType,
+                                const DirectoryLookup *DirLookup) {
   bool Invalid;
   const MemoryBuffer &FromFile = *SM.getBuffer(FileId, &Invalid);
   assert(!Invalid && "Attempting to process invalid inclusion");
@@ -475,7 +480,7 @@ void InclusionRewriter::Process(FileID FileId,
                    << Mod->getFullModuleName(true) << "\n";
 
               // Include and recursively process the file.
-              Process(Inc->Id, Inc->FileType);
+              Process(Inc->Id, Inc->FileType, Inc->DirLookup);
 
               if (Mod)
                 OS << "#pragma clang module end /*"
@@ -532,11 +537,10 @@ void InclusionRewriter::Process(FileID FileId,
                   // Rewrite __has_include_next(x)
                 } else if (RawToken.getIdentifierInfo()->isStr(
                                "__has_include_next")) {
-                  const DirectoryLookup *Lookup = PP.GetCurDirLookup();
-                  if (Lookup)
-                    ++Lookup;
+                  if (DirLookup)
+                    ++DirLookup;
 
-                  if (!HandleHasInclude(FileId, RawLex, Lookup, RawToken,
+                  if (!HandleHasInclude(FileId, RawLex, DirLookup, RawToken,
                                         HasFile))
                     continue;
                 } else {
@@ -621,7 +625,7 @@ void clang::RewriteIncludesInInput(Preprocessor &PP, raw_ostream *OS,
       Rewrite->handleModuleBegin(Tok);
   } while (Tok.isNot(tok::eof));
   Rewrite->setPredefinesBuffer(SM.getBuffer(PP.getPredefinesFileID()));
-  Rewrite->Process(PP.getPredefinesFileID(), SrcMgr::C_User);
-  Rewrite->Process(SM.getMainFileID(), SrcMgr::C_User);
+  Rewrite->Process(PP.getPredefinesFileID(), SrcMgr::C_User, nullptr);
+  Rewrite->Process(SM.getMainFileID(), SrcMgr::C_User, nullptr);
   OS->flush();
 }