Implement (de-)serialization of the buffer contents for an overridden

file in the source manager. This allows us to properly create and use
modules described by module map files without umbrella headers (or
with incompletely umbrella headers). More generally, we can actually
build a PCH file that makes use of  file -> buffer remappings, which
could be useful in libclang in the future.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144830 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index 5555557b98dcbc022f4afa354998fc2b486f10b1..cfd0430e6010fb4ee45ac4d1be887234925f3ca2 100644 (file)
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -102,8 +102,15 @@ namespace SrcMgr {
 
     /// NumLines - The number of lines in this ContentCache.  This is only valid
     /// if SourceLineCache is non-null.
-    unsigned NumLines;
+    unsigned NumLines : 31;
 
+    /// \brief Indicates whether the buffer itself was provided to override
+    /// the actual file contents.
+    ///
+    /// When true, the original entry may be a virtual file that does not
+    /// exist.
+    unsigned BufferOverridden : 1;
+    
     /// getBuffer - Returns the memory buffer for the associated content.
     ///
     /// \param Diag Object through which diagnostics will be emitted if the

diff --git a/include/clang/Serialization/ASTBitCodes.h b/include/clang/Serialization/ASTBitCodes.h
index e3a1020123e2001ba80ad25e91bfeb36dc16c291..53d970b6845b7a55881b47846abb8a31289b6c86 100644 (file)
--- a/include/clang/Serialization/ASTBitCodes.h
+++ b/include/clang/Serialization/ASTBitCodes.h
@@ -452,7 +452,8 @@ namespace clang {
       SM_SLOC_BUFFER_ENTRY = 2,
       /// \brief Describes a blob that contains the data for a buffer
       /// entry. This kind of record always directly follows a
-      /// SM_SLOC_BUFFER_ENTRY record.
+      /// SM_SLOC_BUFFER_ENTRY record or a SM_SLOC_FILE_ENTRY with an
+      /// overridden buffer.
       SM_SLOC_BUFFER_BLOB = 3,
       /// \brief Describes a source location entry (SLocEntry) for a
       /// macro expansion.

diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index ddb1f39d1d672f2914ffab09938e98e90d71c4b6..cdaff2f0082b25790ca1879d1406d491a3c201df 100644 (file)
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -580,6 +580,7 @@ void SourceManager::overrideFileContents(const FileEntry *SourceFile,
   assert(IR && "getOrCreateContentCache() cannot return NULL");
 
   const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(Buffer, DoNotFree);
+  const_cast<SrcMgr::ContentCache *>(IR)->BufferOverridden = true;
 }
 
 void SourceManager::overrideFileContents(const FileEntry *SourceFile,

diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 8961974856b67d5a02f41e75b2829eee3df53b13..0b2a884f82a40841340b17a0528fc961da1276fc 100644 (file)
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1081,9 +1081,18 @@ ASTReader::ASTReadResult ASTReader::ReadSLocEntryRecord(int ID) {
     return Failure;
 
   case SM_SLOC_FILE_ENTRY: {
-    std::string Filename(BlobStart, BlobStart + BlobLen);
+    if (Record.size() < 7) {
+      Error("source location entry is incorrect");
+      return Failure;
+    }
+
+    bool OverriddenBuffer = Record[6];
+    
+    std::string OrigFilename(BlobStart, BlobStart + BlobLen);
+    std::string Filename = OrigFilename;
     MaybeAddSystemRootToFilename(Filename);
-    const FileEntry *File = FileMgr.getFile(Filename);
+    const FileEntry *File = FileMgr.getFile(Filename, /*OpenFile=*/false,
+                                            /*CacheFailure=*/!OverriddenBuffer);
     if (File == 0 && !OriginalDir.empty() && !CurrentDir.empty() &&
         OriginalDir != CurrentDir) {
       std::string resolved = resolveFileRelativeToOriginalDir(Filename,
@@ -1103,11 +1112,6 @@ ASTReader::ASTReadResult ASTReader::ReadSLocEntryRecord(int ID) {
       return Failure;
     }
 
-    if (Record.size() < 6) {
-      Error("source location entry is incorrect");
-      return Failure;
-    }
-
     if (!DisableValidation &&
         ((off_t)Record[4] != File->getSize()
 #if !defined(LLVM_ON_WIN32)
@@ -1131,18 +1135,35 @@ ASTReader::ASTReadResult ASTReader::ReadSLocEntryRecord(int ID) {
                                         ID, BaseOffset + Record[0]);
     SrcMgr::FileInfo &FileInfo =
           const_cast<SrcMgr::FileInfo&>(SourceMgr.getSLocEntry(FID).getFile());
-    FileInfo.NumCreatedFIDs = Record[6];
+    FileInfo.NumCreatedFIDs = Record[7];
     if (Record[3])
       FileInfo.setHasLineDirectives();
 
-    const DeclID *FirstDecl = F->FileSortedDecls + Record[7];
-    unsigned NumFileDecls = Record[8];
+    const DeclID *FirstDecl = F->FileSortedDecls + Record[8];
+    unsigned NumFileDecls = Record[9];
     if (NumFileDecls) {
       assert(F->FileSortedDecls && "FILE_SORTED_DECLS not encountered yet ?");
       FileDeclIDs[FID] = FileDeclsInfo(F, llvm::makeArrayRef(FirstDecl,
                                                              NumFileDecls));
     }
     
+    if (OverriddenBuffer &&
+        !SourceMgr.getOrCreateContentCache(File)->BufferOverridden) {
+      unsigned Code = SLocEntryCursor.ReadCode();
+      Record.clear();
+      unsigned RecCode
+        = SLocEntryCursor.ReadRecord(Code, Record, &BlobStart, &BlobLen);
+      
+      if (RecCode != SM_SLOC_BUFFER_BLOB) {
+        Error("AST record has invalid code");
+        return Failure;
+      }
+      
+      llvm::MemoryBuffer *Buffer
+        = llvm::MemoryBuffer::getMemBuffer(StringRef(BlobStart, BlobLen - 1),
+                                           Filename);
+      SourceMgr.overrideFileContents(File, Buffer);
+    }
     break;
   }
 
@@ -1160,8 +1181,8 @@ ASTReader::ASTReadResult ASTReader::ReadSLocEntryRecord(int ID) {
     }
 
     llvm::MemoryBuffer *Buffer
-    = llvm::MemoryBuffer::getMemBuffer(StringRef(BlobStart, BlobLen - 1),
-                                       Name);
+      = llvm::MemoryBuffer::getMemBuffer(StringRef(BlobStart, BlobLen - 1),
+                                         Name);
     FileID BufferID = SourceMgr.createFileIDForMemBuffer(Buffer, ID,
                                                          BaseOffset + Offset);
 
@@ -2341,6 +2362,10 @@ ASTReader::ASTReadResult ASTReader::validateFileEntries(Module &M) {
       return Failure;
 
     case SM_SLOC_FILE_ENTRY: {
+      // If the buffer was overridden, the file need not exist.
+      if (Record[6])
+        break;
+      
       StringRef Filename(BlobStart, BlobLen);
       const FileEntry *File = getFileEntry(Filename);
 
@@ -2352,7 +2377,7 @@ ASTReader::ASTReadResult ASTReader::validateFileEntries(Module &M) {
         return IgnorePCH;
       }
 
-      if (Record.size() < 6) {
+      if (Record.size() < 7) {
         Error("source location entry is incorrect");
         return Failure;
       }

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 6893dbd9f578d8fd034d165b75b61a7a66db5940..51aadb35e5c264d30754c6085546e235fdb6381a 100644 (file)
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1174,6 +1174,7 @@ static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
   // FileEntry fields.
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // BufferOverridden
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
@@ -1421,7 +1422,8 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
     // Figure out which record code to use.
     unsigned Code;
     if (SLoc->isFile()) {
-      if (SLoc->getFile().getContentCache()->OrigEntry) {
+      const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
+      if (Cache->OrigEntry) {
         Code = SM_SLOC_FILE_ENTRY;
         SLocFileEntryOffsets.push_back(Stream.GetCurrentBitNo());
       } else
@@ -1442,7 +1444,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
       const SrcMgr::ContentCache *Content = File.getContentCache();
       if (Content->OrigEntry) {
         assert(Content->OrigEntry == Content->ContentsEntry &&
-               "Writing to AST an overriden file is not supported");
+               "Writing to AST an overridden file is not supported");
 
         // The source location entry is a file. The blob associated
         // with this entry is the file name.
@@ -1450,7 +1452,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
         // Emit size/modification time for this file.
         Record.push_back(Content->OrigEntry->getSize());
         Record.push_back(Content->OrigEntry->getModificationTime());
-
+        Record.push_back(Content->BufferOverridden);
         Record.push_back(File.NumCreatedFIDs);
         
         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(SLoc);
@@ -1461,7 +1463,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
           Record.push_back(0);
           Record.push_back(0);
         }
-
+        
         // Turn the file name into an absolute path, if it isn't already.
         const char *Filename = Content->OrigEntry->getName();
         llvm::SmallString<128> FilePath(Filename);
@@ -1477,6 +1479,16 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
 
         Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
         Stream.EmitRecordWithBlob(SLocFileAbbrv, Record, Filename);
+        
+        if (Content->BufferOverridden) {
+          Record.clear();
+          Record.push_back(SM_SLOC_BUFFER_BLOB);
+          const llvm::MemoryBuffer *Buffer
+            = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
+          Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
+                                    StringRef(Buffer->getBufferStart(),
+                                              Buffer->getBufferSize() + 1));          
+        }
       } else {
         // The source location entry is a buffer. The blob associated
         // with this entry contains the contents of the buffer.

diff --git a/test/Modules/normal-module-map.cpp b/test/Modules/normal-module-map.cpp
index 9e9f31578d6cd1f0657f4c92764845a00683e5b6..c8338b7061d1f5469c6a57a2baa1912a24a5af4c 100644 (file)
--- a/test/Modules/normal-module-map.cpp
+++ b/test/Modules/normal-module-map.cpp
@@ -1,4 +1,8 @@
 // RUN: rm -rf %t
+// FIXME: Eventually, we should be able to remove these explicit module creation lines
+// RUN: %clang_cc1 -x objective-c -fmodule-cache-path %t -fmodule-name=libA -emit-module-from-map %S/Inputs/normal-module-map/module.map
+// RUN: %clang_cc1 -x objective-c -fmodule-cache-path %t -fmodule-name=libB -emit-module-from-map %S/Inputs/normal-module-map/module.map
+// RUN: %clang_cc1 -x objective-c -fmodule-cache-path %t -fmodule-name=libNested -emit-module-from-map %S/Inputs/normal-module-map/nested/module.map
 // RUN: %clang_cc1 -x objective-c -fmodule-cache-path %t -fauto-module-import -I %S/Inputs/normal-module-map %s -verify
 #include "Umbrella/Umbrella.h"
 
@@ -8,9 +12,7 @@ int getUmbrella() {
 
 __import_module__ Umbrella2;
 
-// FIXME: The expected error here is temporary, since we don't yet have the
-// logic to build a module from a module map.
-#include "a1.h" // expected-error{{module 'libA' not found}}
+#include "a1.h"
 #include "b1.h"
 #include "nested/nested2.h"