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-rw-r--r--clang/include/clang/Serialization/ASTBitCodes.h5
-rw-r--r--clang/include/clang/Serialization/ASTReader.h1
-rw-r--r--clang/include/clang/Serialization/Module.h6
-rw-r--r--clang/include/clang/Serialization/ModuleManager.h9
-rw-r--r--clang/lib/Serialization/ASTReader.cpp42
-rw-r--r--clang/lib/Serialization/ASTWriter.cpp16
-rw-r--r--clang/lib/Serialization/GlobalModuleIndex.cpp4
-rw-r--r--clang/lib/Serialization/Module.cpp2
-rw-r--r--clang/lib/Serialization/ModuleManager.cpp18
-rw-r--r--clang/test/Modules/rebuild.m29
10 files changed, 128 insertions, 4 deletions
diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index 26e0ecde15c..241c62e4ced 100644
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -288,7 +288,10 @@ namespace clang {
/// \brief Record code for the module map file that was used to build this
/// AST file.
- MODULE_MAP_FILE = 14
+ MODULE_MAP_FILE = 14,
+
+ /// \brief Record code for the signature that identifiers this AST file.
+ SIGNATURE = 15
};
/// \brief Record types that occur within the input-files block
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 730a257bca8..d967ec8d212 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -1125,6 +1125,7 @@ private:
SourceLocation ImportLoc, ModuleFile *ImportedBy,
SmallVectorImpl<ImportedModule> &Loaded,
off_t ExpectedSize, time_t ExpectedModTime,
+ serialization::ASTFileSignature ExpectedSignature,
unsigned ClientLoadCapabilities);
ASTReadResult ReadControlBlock(ModuleFile &F,
SmallVectorImpl<ImportedModule> &Loaded,
diff --git a/clang/include/clang/Serialization/Module.h b/clang/include/clang/Serialization/Module.h
index a889e8b6540..f6889cfe8e1 100644
--- a/clang/include/clang/Serialization/Module.h
+++ b/clang/include/clang/Serialization/Module.h
@@ -97,6 +97,8 @@ public:
bool isNotFound() const { return Val.getInt() == NotFound; }
};
+typedef unsigned ASTFileSignature;
+
/// \brief Information about a module that has been loaded by the ASTReader.
///
/// Each instance of the Module class corresponds to a single AST file, which
@@ -152,6 +154,10 @@ public:
/// \brief The file entry for the module file.
const FileEntry *File;
+ /// \brief The signature of the module file, which may be used along with size
+ /// and modification time to identify this particular file.
+ ASTFileSignature Signature;
+
/// \brief Whether this module has been directly imported by the
/// user.
bool DirectlyImported;
diff --git a/clang/include/clang/Serialization/ModuleManager.h b/clang/include/clang/Serialization/ModuleManager.h
index 96c3619510a..3d10fad0a1b 100644
--- a/clang/include/clang/Serialization/ModuleManager.h
+++ b/clang/include/clang/Serialization/ModuleManager.h
@@ -179,6 +179,12 @@ public:
/// \param ExpectedModTime The expected modification time of the module
/// file, used for validation. This will be zero if unknown.
///
+ /// \param ExpectedSignature The expected signature of the module file, used
+ /// for validation. This will be zero if unknown.
+ ///
+ /// \param ReadSignature Reads the signature from an AST file without actually
+ /// loading it.
+ ///
/// \param Module A pointer to the module file if the module was successfully
/// loaded.
///
@@ -191,6 +197,9 @@ public:
SourceLocation ImportLoc,
ModuleFile *ImportedBy, unsigned Generation,
off_t ExpectedSize, time_t ExpectedModTime,
+ ASTFileSignature ExpectedSignature,
+ std::function<ASTFileSignature(llvm::BitstreamReader &)>
+ ReadSignature,
ModuleFile *&Module,
std::string &ErrorStr);
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index f3181546320..80b1c2b6bcc 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2363,6 +2363,11 @@ ASTReader::ReadControlBlock(ModuleFile &F,
break;
}
+ case SIGNATURE:
+ assert((!F.Signature || F.Signature == Record[0]) && "signature changed");
+ F.Signature = Record[0];
+ break;
+
case IMPORTS: {
// Load each of the imported PCH files.
unsigned Idx = 0, N = Record.size();
@@ -2376,6 +2381,7 @@ ASTReader::ReadControlBlock(ModuleFile &F,
SourceLocation::getFromRawEncoding(Record[Idx++]);
off_t StoredSize = (off_t)Record[Idx++];
time_t StoredModTime = (time_t)Record[Idx++];
+ ASTFileSignature StoredSignature = Record[Idx++];
unsigned Length = Record[Idx++];
SmallString<128> ImportedFile(Record.begin() + Idx,
Record.begin() + Idx + Length);
@@ -2383,7 +2389,7 @@ ASTReader::ReadControlBlock(ModuleFile &F,
// Load the AST file.
switch(ReadASTCore(ImportedFile, ImportedKind, ImportLoc, &F, Loaded,
- StoredSize, StoredModTime,
+ StoredSize, StoredModTime, StoredSignature,
ClientLoadCapabilities)) {
case Failure: return Failure;
// If we have to ignore the dependency, we'll have to ignore this too.
@@ -3552,7 +3558,7 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
SmallVector<ImportedModule, 4> Loaded;
switch(ASTReadResult ReadResult = ReadASTCore(FileName, Type, ImportLoc,
/*ImportedBy=*/nullptr, Loaded,
- 0, 0,
+ 0, 0, 0,
ClientLoadCapabilities)) {
case Failure:
case Missing:
@@ -3719,6 +3725,8 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
return Success;
}
+static ASTFileSignature readASTFileSignature(llvm::BitstreamReader &StreamFile);
+
ASTReader::ASTReadResult
ASTReader::ReadASTCore(StringRef FileName,
ModuleKind Type,
@@ -3726,12 +3734,14 @@ ASTReader::ReadASTCore(StringRef FileName,
ModuleFile *ImportedBy,
SmallVectorImpl<ImportedModule> &Loaded,
off_t ExpectedSize, time_t ExpectedModTime,
+ ASTFileSignature ExpectedSignature,
unsigned ClientLoadCapabilities) {
ModuleFile *M;
std::string ErrorStr;
ModuleManager::AddModuleResult AddResult
= ModuleMgr.addModule(FileName, Type, ImportLoc, ImportedBy,
getGeneration(), ExpectedSize, ExpectedModTime,
+ ExpectedSignature, readASTFileSignature,
M, ErrorStr);
switch (AddResult) {
@@ -4029,6 +4039,34 @@ static bool SkipCursorToBlock(BitstreamCursor &Cursor, unsigned BlockID) {
}
}
+static ASTFileSignature readASTFileSignature(llvm::BitstreamReader &StreamFile){
+ BitstreamCursor Stream(StreamFile);
+ if (Stream.Read(8) != 'C' ||
+ Stream.Read(8) != 'P' ||
+ Stream.Read(8) != 'C' ||
+ Stream.Read(8) != 'H') {
+ return 0;
+ }
+
+ // Scan for the CONTROL_BLOCK_ID block.
+ if (SkipCursorToBlock(Stream, CONTROL_BLOCK_ID))
+ return 0;
+
+ // Scan for SIGNATURE inside the control block.
+ ASTReader::RecordData Record;
+ while (1) {
+ llvm::BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
+ if (Entry.Kind == llvm::BitstreamEntry::EndBlock ||
+ Entry.Kind != llvm::BitstreamEntry::Record)
+ return 0;
+
+ Record.clear();
+ StringRef Blob;
+ if (SIGNATURE == Stream.readRecord(Entry.ID, Record, &Blob))
+ return Record[0];
+ }
+}
+
/// \brief Retrieve the name of the original source file name
/// directly from the AST file, without actually loading the AST
/// file.
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 0681e3975d2..e39e5bb0222 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -51,6 +51,7 @@
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/OnDiskHashTable.h"
#include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
#include <algorithm>
#include <cstdio>
#include <string.h>
@@ -862,6 +863,7 @@ void ASTWriter::WriteBlockInfoBlock() {
// Control Block.
BLOCK(CONTROL_BLOCK);
RECORD(METADATA);
+ RECORD(SIGNATURE);
RECORD(MODULE_NAME);
RECORD(MODULE_MAP_FILE);
RECORD(IMPORTS);
@@ -1092,6 +1094,14 @@ adjustFilenameForRelocatablePCH(const char *Filename, StringRef isysroot) {
return Filename + Pos;
}
+static ASTFileSignature getSignature() {
+ while (1) {
+ if (ASTFileSignature S = llvm::sys::Process::GetRandomNumber())
+ return S;
+ // Rely on GetRandomNumber to eventually return non-zero...
+ }
+}
+
/// \brief Write the control block.
void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
StringRef isysroot,
@@ -1121,6 +1131,11 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
getClangFullRepositoryVersion());
+ // Signature
+ Record.clear();
+ Record.push_back(getSignature());
+ Stream.EmitRecord(SIGNATURE, Record);
+
// Module name
if (WritingModule) {
BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
@@ -1173,6 +1188,7 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
AddSourceLocation((*M)->ImportLoc, Record);
Record.push_back((*M)->File->getSize());
Record.push_back((*M)->File->getModificationTime());
+ Record.push_back((*M)->Signature);
const std::string &FileName = (*M)->FileName;
Record.push_back(FileName.size());
Record.append(FileName.begin(), FileName.end());
diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index f43fbaca140..121478ce052 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -591,6 +591,10 @@ bool GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
off_t StoredSize = (off_t)Record[Idx++];
time_t StoredModTime = (time_t)Record[Idx++];
+ // Skip the stored signature.
+ // FIXME: we could read the signature out of the import and validate it.
+ Idx++;
+
// Retrieve the imported file name.
unsigned Length = Record[Idx++];
SmallString<128> ImportedFile(Record.begin() + Idx,
diff --git a/clang/lib/Serialization/Module.cpp b/clang/lib/Serialization/Module.cpp
index 6f2a3c22043..6c48a41187c 100644
--- a/clang/lib/Serialization/Module.cpp
+++ b/clang/lib/Serialization/Module.cpp
@@ -21,7 +21,7 @@ using namespace serialization;
using namespace reader;
ModuleFile::ModuleFile(ModuleKind Kind, unsigned Generation)
- : Kind(Kind), File(nullptr), DirectlyImported(false),
+ : Kind(Kind), File(nullptr), Signature(0), DirectlyImported(false),
Generation(Generation), SizeInBits(0),
LocalNumSLocEntries(0), SLocEntryBaseID(0),
SLocEntryBaseOffset(0), SLocEntryOffsets(nullptr),
diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index 20249e0a7bd..300ef31b590 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -57,6 +57,9 @@ ModuleManager::addModule(StringRef FileName, ModuleKind Type,
SourceLocation ImportLoc, ModuleFile *ImportedBy,
unsigned Generation,
off_t ExpectedSize, time_t ExpectedModTime,
+ ASTFileSignature ExpectedSignature,
+ std::function<ASTFileSignature(llvm::BitstreamReader &)>
+ ReadSignature,
ModuleFile *&Module,
std::string &ErrorStr) {
Module = nullptr;
@@ -130,6 +133,21 @@ ModuleManager::addModule(StringRef FileName, ModuleKind Type,
// Initialize the stream
New->StreamFile.init((const unsigned char *)New->Buffer->getBufferStart(),
(const unsigned char *)New->Buffer->getBufferEnd());
+
+ if (ExpectedSignature) {
+ New->Signature = ReadSignature(New->StreamFile);
+ if (New->Signature != ExpectedSignature) {
+ ErrorStr = New->Signature ? "signature mismatch"
+ : "could not read module signature";
+
+ // Remove the module file immediately, since removeModules might try to
+ // invalidate the file cache for Entry, and that is not safe if this
+ // module is *itself* up to date, but has an out-of-date importer.
+ Modules.erase(Entry);
+ Chain.pop_back();
+ return OutOfDate;
+ }
+ }
}
if (ImportedBy) {
diff --git a/clang/test/Modules/rebuild.m b/clang/test/Modules/rebuild.m
new file mode 100644
index 00000000000..c6e7920339e
--- /dev/null
+++ b/clang/test/Modules/rebuild.m
@@ -0,0 +1,29 @@
+// REQUIRES: shell
+// RUN: rm -rf %t
+
+// Build Module and set its timestamp
+// RUN: echo '@import Module;' | %clang_cc1 -fmodules -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs -x objective-c -
+// RUN: touch -m -a -t 201101010000 %t/Module.pcm
+// RUN: cp %t/Module.pcm %t/Module.pcm.saved
+// RUN: wc -c %t/Module.pcm > %t/Module.size.saved
+
+// Build DependsOnModule
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs %s
+// RUN: diff %t/Module.pcm %t/Module.pcm.saved
+// RUN: cp %t/DependsOnModule.pcm %t/DependsOnModule.pcm.saved
+
+// Rebuild Module, reset its timestamp, and verify its size hasn't changed
+// RUN: rm %t/Module.pcm
+// RUN: echo '@import Module;' | %clang_cc1 -fmodules -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs -x objective-c -
+// RUN: touch -m -a -t 201101010000 %t/Module.pcm
+// RUN: wc -c %t/Module.pcm > %t/Module.size
+// RUN: diff %t/Module.size %t/Module.size.saved
+// RUN: cp %t/Module.pcm %t/Module.pcm.saved.2
+
+// But the signature at least is expected to change, so we rebuild DependsOnModule.
+// NOTE: if we change how the signature is created, this test may need updating.
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -fdisable-module-hash -fsyntax-only -F %S/Inputs %s
+// RUN: diff %t/Module.pcm %t/Module.pcm.saved.2
+// RUN: not diff %t/DependsOnModule.pcm %t/DependsOnModule.pcm.saved
+
+@import DependsOnModule;
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