#include "llvm/Support/Parallel.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/RandomNumberGenerator.h"
+#include "llvm/Support/xxhash.h"
#include <algorithm>
#include <cstdio>
#include <map>
uint64_t Offs = OS->getFileOff() + (Record->getRVA() - OS->getRVA());
D->PointerToRawData = Offs;
+ TimeDateStamps.push_back(&D->TimeDateStamp);
++D;
}
}
+ void setTimeDateStamp(uint32_t TimeDateStamp) {
+ for (support::ulittle32_t *TDS : TimeDateStamps)
+ *TDS = TimeDateStamp;
+ }
+
private:
+ mutable std::vector<support::ulittle32_t *> TimeDateStamps;
const std::vector<Chunk *> &Records;
};
RVATableChunk *GuardFidsTable = nullptr;
RVATableChunk *SEHTable = nullptr;
- Chunk *DebugDirectory = nullptr;
+ DebugDirectoryChunk *DebugDirectory = nullptr;
std::vector<Chunk *> DebugRecords;
CVDebugRecordChunk *BuildId = nullptr;
Optional<codeview::DebugInfo> PreviousBuildId;
}
void Writer::writeBuildId() {
- // If we're not writing a build id (e.g. because /debug is not specified),
- // then just return;
- if (!Config->Debug)
- return;
+ // There are two important parts to the build ID.
+ // 1) If building with debug info, the COFF debug directory contains a
+ // timestamp as well as a Guid and Age of the PDB.
+ // 2) In all cases, the PE COFF file header also contains a timestamp.
+ // For reproducibility, instead of a timestamp we want to use a hash of the
+ // binary, however when building with debug info the hash needs to take into
+ // account the debug info, since it's possible to add blank lines to a file
+ // which causes the debug info to change but not the generated code.
+ //
+ // To handle this, we first set the Guid and Age in the debug directory (but
+ // only if we're doing a debug build). Then, we hash the binary (thus causing
+ // the hash to change if only the debug info changes, since the Age will be
+ // different). Finally, we write that hash into the debug directory (if
+ // present) as well as the COFF file header (always).
+ if (Config->Debug) {
+ assert(BuildId && "BuildId is not set!");
+ if (PreviousBuildId.hasValue()) {
+ *BuildId->BuildId = *PreviousBuildId;
+ BuildId->BuildId->PDB70.Age = BuildId->BuildId->PDB70.Age + 1;
+ } else {
+ BuildId->BuildId->Signature.CVSignature = OMF::Signature::PDB70;
+ BuildId->BuildId->PDB70.Age = 1;
+ llvm::getRandomBytes(BuildId->BuildId->PDB70.Signature, 16);
+ }
+ }
- assert(BuildId && "BuildId is not set!");
+ // At this point the only fields in the COFF file which remain unset are the
+ // "timestamp" in the COFF file header, and the ones in the coff debug
+ // directory. Now we can hash the file and write that hash to the various
+ // timestamp fields in the file.
+ StringRef OutputFileData(
+ reinterpret_cast<const char *>(Buffer->getBufferStart()),
+ Buffer->getBufferSize());
- if (PreviousBuildId.hasValue()) {
- *BuildId->BuildId = *PreviousBuildId;
- BuildId->BuildId->PDB70.Age = BuildId->BuildId->PDB70.Age + 1;
- return;
- }
+ uint32_t Hash = static_cast<uint32_t>(xxHash64(OutputFileData));
+
+ if (DebugDirectory)
+ DebugDirectory->setTimeDateStamp(Hash);
- BuildId->BuildId->Signature.CVSignature = OMF::Signature::PDB70;
- BuildId->BuildId->PDB70.Age = 1;
- llvm::getRandomBytes(BuildId->BuildId->PDB70.Signature, 16);
+ uint8_t *Buf = Buffer->getBufferStart();
+ Buf += DOSStubSize + sizeof(PEMagic);
+ object::coff_file_header *CoffHeader =
+ reinterpret_cast<coff_file_header *>(Buf);
+ CoffHeader->TimeDateStamp = Hash;
}
// Sort .pdata section contents according to PE/COFF spec 5.5.
projects / platform / upstream / llvm.git / commitdiff