Make precompiled headers work with -E. When we're only preprocessing
(with -E), we turn the PCH include into an implicit include of the
file from which the PCH file was generated.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71534 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 759865c..ab7ad04 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -1218,6 +1218,10 @@
}
ObjCCategoryImpls.swap(Record);
break;
+
+ case pch::ORIGINAL_FILE_NAME:
+ OriginalFileName.assign(BlobStart, BlobLen);
+ break;
}
}
Error("premature end of bitstream in PCH file");
@@ -1364,6 +1368,87 @@
return Success;
}
+/// \brief Retrieve the name of the original source file name
+/// directly from the PCH file, without actually loading the PCH
+/// file.
+std::string PCHReader::getOriginalSourceFile(const std::string &PCHFileName) {
+ // Open the PCH file.
+ std::string ErrStr;
+ llvm::OwningPtr<llvm::MemoryBuffer> Buffer;
+ Buffer.reset(llvm::MemoryBuffer::getFile(PCHFileName.c_str(), &ErrStr));
+ if (!Buffer) {
+ fprintf(stderr, "error: %s\n", ErrStr.c_str());
+ return std::string();
+ }
+
+ // Initialize the stream
+ llvm::BitstreamReader StreamFile;
+ llvm::BitstreamCursor Stream;
+ StreamFile.init((const unsigned char *)Buffer->getBufferStart(),
+ (const unsigned char *)Buffer->getBufferEnd());
+ Stream.init(StreamFile);
+
+ // Sniff for the signature.
+ if (Stream.Read(8) != 'C' ||
+ Stream.Read(8) != 'P' ||
+ Stream.Read(8) != 'C' ||
+ Stream.Read(8) != 'H') {
+ fprintf(stderr,
+ "error: '%s' does not appear to be a precompiled header file\n",
+ PCHFileName.c_str());
+ return std::string();
+ }
+
+ RecordData Record;
+ while (!Stream.AtEndOfStream()) {
+ unsigned Code = Stream.ReadCode();
+
+ if (Code == llvm::bitc::ENTER_SUBBLOCK) {
+ unsigned BlockID = Stream.ReadSubBlockID();
+
+ // We only know the PCH subblock ID.
+ switch (BlockID) {
+ case pch::PCH_BLOCK_ID:
+ if (Stream.EnterSubBlock(pch::PCH_BLOCK_ID)) {
+ fprintf(stderr, "error: malformed block record in PCH file\n");
+ return std::string();
+ }
+ break;
+
+ default:
+ if (Stream.SkipBlock()) {
+ fprintf(stderr, "error: malformed block record in PCH file\n");
+ return std::string();
+ }
+ break;
+ }
+ continue;
+ }
+
+ if (Code == llvm::bitc::END_BLOCK) {
+ if (Stream.ReadBlockEnd()) {
+ fprintf(stderr, "error: error at end of module block in PCH file\n");
+ return std::string();
+ }
+ continue;
+ }
+
+ if (Code == llvm::bitc::DEFINE_ABBREV) {
+ Stream.ReadAbbrevRecord();
+ continue;
+ }
+
+ Record.clear();
+ const char *BlobStart = 0;
+ unsigned BlobLen = 0;
+ if (Stream.ReadRecord(Code, Record, &BlobStart, &BlobLen)
+ == pch::ORIGINAL_FILE_NAME)
+ return std::string(BlobStart, BlobLen);
+ }
+
+ return std::string();
+}
+
/// \brief Parse the record that corresponds to a LangOptions data
/// structure.
///