Modules: Use hash of PCM content for SIGNATURE
Change ASTFileSignature from a random 32-bit number to the hash of the
PCM content.
- Move definition ASTFileSignature to Basic/Module.h so Module and
ASTSourceDescriptor can use it.
- Change the signature from uint64_t to std::array<uint32_t,5>.
- Stop using (saving/reading) the size and modification time of PCM
files when there is a valid SIGNATURE.
- Add UNHASHED_CONTROL_BLOCK, and use it to store the SIGNATURE record
and other records that shouldn't affect the hash. Because implicit
modules reuses the same file for multiple levels of -Werror, this
includes DIAGNOSTIC_OPTIONS and DIAG_PRAGMA_MAPPINGS.
This helps to solve a PCH + implicit Modules dependency issue: PCH files
are handled by the external build system, whereas implicit modules are
handled by internal compiler build system. This prevents invalidating a
PCH when the compiler overwrites a PCM file with the same content
(modulo the diagnostic differences).
Design and original patch by Manman Ren!
llvm-svn: 297655
diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index ae5796e..6978e7e 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -376,6 +376,15 @@
/// \brief The set of modules on which this module depends. Each entry is
/// a module ID.
SmallVector<unsigned, 4> Dependencies;
+ ASTFileSignature Signature;
+ };
+
+ struct ImportedModuleFileInfo {
+ off_t StoredSize;
+ time_t StoredModTime;
+ ASTFileSignature StoredSignature;
+ ImportedModuleFileInfo(off_t Size, time_t ModTime, ASTFileSignature Sig)
+ : StoredSize(Size), StoredModTime(ModTime), StoredSignature(Sig) {}
};
/// \brief Builder that generates the global module index file.
@@ -383,12 +392,20 @@
FileManager &FileMgr;
const PCHContainerReader &PCHContainerRdr;
- /// \brief Mapping from files to module file information.
+ /// Mapping from files to module file information.
typedef llvm::MapVector<const FileEntry *, ModuleFileInfo> ModuleFilesMap;
- /// \brief Information about each of the known module files.
+ /// Information about each of the known module files.
ModuleFilesMap ModuleFiles;
+ /// \brief Mapping from the imported module file to the imported
+ /// information.
+ typedef std::multimap<const FileEntry *, ImportedModuleFileInfo>
+ ImportedModuleFilesMap;
+
+ /// \brief Information about each importing of a module file.
+ ImportedModuleFilesMap ImportedModuleFiles;
+
/// \brief Mapping from identifiers to the list of module file IDs that
/// consider this identifier to be interesting.
typedef llvm::StringMap<SmallVector<unsigned, 2> > InterestingIdentifierMap;
@@ -424,7 +441,8 @@
bool loadModuleFile(const FileEntry *File);
/// \brief Write the index to the given bitstream.
- void writeIndex(llvm::BitstreamWriter &Stream);
+ /// \returns true if an error occurred, false otherwise.
+ bool writeIndex(llvm::BitstreamWriter &Stream);
};
}
@@ -515,7 +533,7 @@
unsigned ID = getModuleFileInfo(File).ID;
// Search for the blocks and records we care about.
- enum { Other, ControlBlock, ASTBlock } State = Other;
+ enum { Other, ControlBlock, ASTBlock, DiagnosticOptionsBlock } State = Other;
bool Done = false;
while (!Done) {
llvm::BitstreamEntry Entry = InStream.advance();
@@ -553,6 +571,15 @@
continue;
}
+ if (Entry.ID == UNHASHED_CONTROL_BLOCK_ID) {
+ if (InStream.EnterSubBlock(UNHASHED_CONTROL_BLOCK_ID))
+ return true;
+
+ // Found the Diagnostic Options block.
+ State = DiagnosticOptionsBlock;
+ continue;
+ }
+
if (InStream.SkipBlock())
return true;
@@ -587,7 +614,10 @@
// Skip the stored signature.
// FIXME: we could read the signature out of the import and validate it.
- Idx++;
+ ASTFileSignature StoredSignature = {
+ {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
+ (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
+ (uint32_t)Record[Idx++]}}};
// Retrieve the imported file name.
unsigned Length = Record[Idx++];
@@ -599,11 +629,16 @@
const FileEntry *DependsOnFile
= FileMgr.getFile(ImportedFile, /*openFile=*/false,
/*cacheFailure=*/false);
- if (!DependsOnFile ||
- (StoredSize != DependsOnFile->getSize()) ||
- (StoredModTime != DependsOnFile->getModificationTime()))
+
+ if (!DependsOnFile)
return true;
+ // Save the information in ImportedModuleFileInfo so we can verify after
+ // loading all pcms.
+ ImportedModuleFiles.insert(std::make_pair(
+ DependsOnFile, ImportedModuleFileInfo(StoredSize, StoredModTime,
+ StoredSignature)));
+
// Record the dependency.
unsigned DependsOnID = getModuleFileInfo(DependsOnFile).ID;
getModuleFileInfo(File).Dependencies.push_back(DependsOnID);
@@ -632,6 +667,12 @@
}
}
+ // Get Signature.
+ if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
+ getModuleFileInfo(File).Signature = {
+ {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
+ (uint32_t)Record[3], (uint32_t)Record[4]}}};
+
// We don't care about this record.
}
@@ -680,7 +721,20 @@
}
-void GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
+bool GlobalModuleIndexBuilder::writeIndex(llvm::BitstreamWriter &Stream) {
+ for (auto MapEntry : ImportedModuleFiles) {
+ auto *File = MapEntry.first;
+ ImportedModuleFileInfo &Info = MapEntry.second;
+ if (getModuleFileInfo(File).Signature) {
+ if (getModuleFileInfo(File).Signature != Info.StoredSignature)
+ // Verify Signature.
+ return true;
+ } else if (Info.StoredSize != File->getSize() ||
+ Info.StoredModTime != File->getModificationTime())
+ // Verify Size and ModTime.
+ return true;
+ }
+
using namespace llvm;
// Emit the file header.
@@ -756,6 +810,7 @@
}
Stream.ExitBlock();
+ return false;
}
GlobalModuleIndex::ErrorCode
@@ -816,7 +871,8 @@
SmallVector<char, 16> OutputBuffer;
{
llvm::BitstreamWriter OutputStream(OutputBuffer);
- Builder.writeIndex(OutputStream);
+ if (Builder.writeIndex(OutputStream))
+ return EC_IOError;
}
// Write the global index file to a temporary file.