Encode the Clang branch and Subversion revision into a PCH file, and
assume that PCH files from different Clang revisions are not
compatible. Addresses <rdar://problem/7266572>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83323 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticFrontendKinds.td b/include/clang/Basic/DiagnosticFrontendKinds.td
index 385b1c2..e5c7327 100644
--- a/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -136,6 +136,8 @@
"PCH file uses an older PCH format that is no longer supported">;
def warn_pch_version_too_new : Error<
"PCH file uses a newer PCH format that cannot be read">;
+def warn_pch_different_branch : Error<
+ "PCH file built from a different branch (%0) than the compiler (%1)">;
def warn_cmdline_conflicting_macro_def : Error<
"definition of the macro '%0' conflicts with the definition used to "
"build the precompiled header">;
diff --git a/include/clang/Frontend/PCHBitCodes.h b/include/clang/Frontend/PCHBitCodes.h
index 2655217..716780e 100644
--- a/include/clang/Frontend/PCHBitCodes.h
+++ b/include/clang/Frontend/PCHBitCodes.h
@@ -29,7 +29,11 @@
/// incompatible with previous versions (such that a reader
/// designed for the previous version could not support reading
/// the new version), this number should be increased.
- const unsigned VERSION_MAJOR = 2;
+ ///
+ /// Version 3 of PCH files also requires that the Subversion branch and
+ /// revision match exactly, since there is no backward compatibility of
+ /// PCH files at this time.
+ const unsigned VERSION_MAJOR = 3;
/// \brief PCH minor version number supported by this version of
/// Clang.
@@ -218,7 +222,11 @@
/// \brief Record code for the sorted array of source ranges where
/// comments were encountered in the source code.
- COMMENT_RANGES = 20
+ COMMENT_RANGES = 20,
+
+ /// \brief Record code for the Subversion branch and revision information
+ /// of the compiler used to build this PCH file.
+ SVN_BRANCH_REVISION = 21
};
/// \brief Record types used within a source manager block.
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index ead00ee..e61668d 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -26,6 +26,7 @@
#include "clang/Basic/SourceManagerInternals.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/Version.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -1340,9 +1341,7 @@
case pch::SOURCE_LOCATION_OFFSETS:
SLocOffsets = (const uint32_t *)BlobStart;
TotalNumSLocEntries = Record[0];
- SourceMgr.PreallocateSLocEntries(this,
- TotalNumSLocEntries,
- Record[1]);
+ SourceMgr.PreallocateSLocEntries(this, TotalNumSLocEntries, Record[1]);
break;
case pch::SOURCE_LOCATION_PRELOADS:
@@ -1377,6 +1376,23 @@
Comments = (SourceRange *)BlobStart;
NumComments = BlobLen / sizeof(SourceRange);
break;
+
+ case pch::SVN_BRANCH_REVISION: {
+ unsigned CurRevision = getClangSubversionRevision();
+ if (Record[0] && CurRevision && Record[0] != CurRevision) {
+ Diag(Record[0] < CurRevision? diag::warn_pch_version_too_old
+ : diag::warn_pch_version_too_new);
+ return IgnorePCH;
+ }
+
+ const char *CurBranch = getClangSubversionPath();
+ if (strncmp(CurBranch, BlobStart, BlobLen)) {
+ std::string PCHBranch(BlobStart, BlobLen);
+ Diag(diag::warn_pch_different_branch) << PCHBranch << CurBranch;
+ return IgnorePCH;
+ }
+ break;
+ }
}
}
Error("premature end of bitstream in PCH file");
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 08a1661..64a678e 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -394,7 +394,8 @@
RECORD(STAT_CACHE);
RECORD(EXT_VECTOR_DECLS);
RECORD(COMMENT_RANGES);
-
+ RECORD(SVN_BRANCH_REVISION);
+
// SourceManager Block.
BLOCK(SOURCE_MANAGER_BLOCK);
RECORD(SM_SLOC_FILE_ENTRY);
@@ -564,6 +565,17 @@
Record.push_back(pch::ORIGINAL_FILE_NAME);
Stream.EmitRecordWithBlob(FileAbbrevCode, Record, MainFileNameStr);
}
+
+ // Subversion branch/version information.
+ BitCodeAbbrev *SvnAbbrev = new BitCodeAbbrev();
+ SvnAbbrev->Add(BitCodeAbbrevOp(pch::SVN_BRANCH_REVISION));
+ SvnAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // SVN revision
+ SvnAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
+ unsigned SvnAbbrevCode = Stream.EmitAbbrev(SvnAbbrev);
+ Record.clear();
+ Record.push_back(pch::SVN_BRANCH_REVISION);
+ Record.push_back(getClangSubversionRevision());
+ Stream.EmitRecordWithBlob(SvnAbbrevCode, Record, getClangSubversionPath());
}
/// \brief Write the LangOptions structure.