[llvm-cov] Support for v4 format in convert-for-testing

[phosek]

Summary

v4 moves function records to a dedicated section so we need to write
and read it separately.

[phosek]

I ran into this issue when trying to create a test for D100232.

[phosek]

Ping?

[zequanwu]

Sorry, I'm not familiar with the format of coverage mapping.

[vsk]

@phosek I apologize for the delay in reviewing this.

Thanks for doing this. I've done a few passes over the logic changes and think they look fine. I think the only thing that's missing is a .covmapping test blob to test the new v4 support.

[phosek]

In D100535#2709646, @vsk wrote:

@phosek I apologize for the delay in reviewing this.

Thanks for doing this. I've done a few passes over the logic changes and think they look fine. I think the only thing that's missing is a .covmapping test blob to test the new v4 support.

Thanks @vsk, I have a test that uses the v4 support in D100232 which should land immediately after this change, is that sufficient?

[vsk]

Sgtm, thanks.

llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp

loadTestingFormat(StringRef Data) {
   if (N > Data.size())
     return make_error<CoverageMapError>(coveragemap_error::malformed);
   Data = Data.substr(N);
   if (Data.size() < ProfileNamesSize)
     return make_error<CoverageMapError>(coveragemap_error::malformed);
   InstrProfSymtab ProfileNames;
   if (Error E = ProfileNames.create(Data.substr(0, ProfileNamesSize), Address))
     return std::move(E);
-  StringRef CoverageMapping = Data.substr(ProfileNamesSize);
+  Data = Data.substr(ProfileNamesSize);
   // Skip the padding bytes because coverage map data has an alignment of 8.
+  size_t Pad = offsetToAlignedAddr(Data.data(), Align(8));
+  if (Data.size() < Pad)
+    return make_error<CoverageMapError>(coveragemap_error::malformed);
+  Data = Data.substr(Pad);
+  if (Data.size() < sizeof(CovMapHeader))
+    return make_error<CoverageMapError>(coveragemap_error::malformed);
+  auto const *CovHeader = reinterpret_cast<const CovMapHeader *>(
+      Data.substr(0, sizeof(CovMapHeader)).data());
+  CovMapVersion Version =
+      (CovMapVersion)CovHeader->getVersion<support::endianness::little>();
+  StringRef CoverageMapping, CoverageRecords;
+  if (Version < CovMapVersion::Version4) {
+    CoverageMapping = Data;
     if (CoverageMapping.empty())
       return make_error<CoverageMapError>(coveragemap_error::truncated);
-  size_t Pad = offsetToAlignedAddr(CoverageMapping.data(), Align(8));
-  if (CoverageMapping.size() < Pad)
+  } else {
+    uint32_t FilenamesSize =
+        CovHeader->getFilenamesSize<support::endianness::little>();
+    uint32_t CoverageMappingSize = sizeof(CovMapHeader) + FilenamesSize;
+    CoverageMapping = Data.substr(0, CoverageMappingSize);
+    if (CoverageMapping.empty())
+      return make_error<CoverageMapError>(coveragemap_error::truncated);
+    Data = Data.substr(CoverageMappingSize);
+    // Skip the padding bytes because coverage records data has an alignment
+    // of 8.
+    Pad = offsetToAlignedAddr(Data.data(), Align(8));
+    if (Data.size() < Pad)
       return make_error<CoverageMapError>(coveragemap_error::malformed);
-  CoverageMapping = CoverageMapping.substr(Pad);
+    CoverageRecords = Data.substr(Pad);
+    if (CoverageRecords.empty())
+      return make_error<CoverageMapError>(coveragemap_error::truncated);
+  }
   return BinaryCoverageReader::createCoverageReaderFromBuffer(
-      CoverageMapping, "", std::move(ProfileNames), BytesInAddress, Endian);
+      CoverageMapping, CoverageRecords.str(), std::move(ProfileNames),
+      BytesInAddress, Endian);
 }
 
 /// Find all sections that match \p Name. There may be more than one if comdats
 /// are in use, e.g. for the __llvm_covfun section on ELF.
 static Expected<std::vector<SectionRef>> lookupSections(ObjectFile &OF,
                                                         StringRef Name) {
   // On COFF, the object file section name may end in "$M". This tells the
   // linker to sort these sections between "$A" and "$Z". The linker removes the

llvm/tools/llvm-cov/TestingSupport.cpp

int convertForTestingMain(int argc, const char *argv[]) {
   auto BytesInAddress = OF->getBytesInAddress();
   if (BytesInAddress != 8) {
     errs() << "error: 64 bit binary expected\n";
     return 1;
   }
 
   // Look for the sections that we are interested in.
   int FoundSectionCount = 0;
-  SectionRef ProfileNames, CoverageMapping;
+  SectionRef ProfileNames, CoverageMapping, CoverageRecords;
   auto ObjFormat = OF->getTripleObjectFormat();
   for (const auto &Section : OF->sections()) {
     StringRef Name;
     if (Expected<StringRef> NameOrErr = Section.getName()) {
       Name = *NameOrErr;
     } else {
       consumeError(NameOrErr.takeError());
       return 1;
     }
 
     if (Name == llvm::getInstrProfSectionName(IPSK_name, ObjFormat,
                                               /*AddSegmentInfo=*/false)) {
       ProfileNames = Section;
     } else if (Name == llvm::getInstrProfSectionName(
                            IPSK_covmap, ObjFormat, /*AddSegmentInfo=*/false)) {
       CoverageMapping = Section;
+    } else if (Name == llvm::getInstrProfSectionName(
+                           IPSK_covfun, ObjFormat, /*AddSegmentInfo=*/false)) {
+      CoverageRecords = Section;
     } else
       continue;
     ++FoundSectionCount;
   }
-  if (FoundSectionCount != 2)
+  if (FoundSectionCount != 3)
     return 1;
 
   // Get the contents of the given sections.
   uint64_t ProfileNamesAddress = ProfileNames.getAddress();
   StringRef CoverageMappingData;
+  StringRef CoverageRecordsData;
   StringRef ProfileNamesData;
   if (Expected<StringRef> E = CoverageMapping.getContents())
     CoverageMappingData = *E;
   else {
     consumeError(E.takeError());
     return 1;
   }
+  if (Expected<StringRef> E = CoverageRecords.getContents())
+    CoverageRecordsData = *E;
+  else {
+    consumeError(E.takeError());
+    return 1;
+  }
   if (Expected<StringRef> E = ProfileNames.getContents())
     ProfileNamesData = *E;
   else {
     consumeError(E.takeError());
     return 1;
   }
 
   int FD;
   if (auto Err = sys::fs::openFileForWrite(OutputFilename, FD)) {
     errs() << "error: " << Err.message() << "\n";
     return 1;
   }
 
   raw_fd_ostream OS(FD, true);
   OS << "llvmcovmtestdata";
   encodeULEB128(ProfileNamesData.size(), OS);
   encodeULEB128(ProfileNamesAddress, OS);
   OS << ProfileNamesData;
   // Coverage mapping data is expected to have an alignment of 8.
   for (unsigned Pad = offsetToAlignment(OS.tell(), Align(8)); Pad; --Pad)
     OS.write(uint8_t(0));
   OS << CoverageMappingData;
+  // Coverage records data is expected to have an alignment of 8.
+  for (unsigned Pad = offsetToAlignment(OS.tell(), Align(8)); Pad; --Pad)
+    OS.write(uint8_t(0));
+  OS << CoverageRecordsData;
 
   return 0;
 }