Revert "[llvm-cov] Fix a bug about using `convert-for-testing` on multi-source object files"

This reverts commit f8ad86c23405168a8cd189590184fdcc296627e0 because
it broke some downsteam tests reported in https://reviews.llvm.org/D156611.

1 files changed, 22 insertions, 27 deletions

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp b/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
index 2f290b2..0573732 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
@@ -886,46 +886,41 @@ loadTestingFormat(StringRef Data, StringRef CompilationDir) {
   if (Error E = ProfileNames.create(Data.substr(0, ProfileNamesSize), Address))
     return std::move(E);
   Data = Data.substr(ProfileNamesSize);
-
-  N = 0;
-  uint64_t CoverageMappingSize = decodeULEB128(Data.bytes_begin(), &N);
-  if (N > Data.size())
-    return make_error<CoverageMapError>(coveragemap_error::malformed);
-  Data = Data.substr(N);
-
   // 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() < CoverageMappingSize)
-    return make_error<CoverageMapError>(coveragemap_error::malformed);
-  StringRef CoverageMapping = Data.substr(0, CoverageMappingSize);
-  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)
+  if (Data.size() < sizeof(CovMapHeader))
     return make_error<CoverageMapError>(coveragemap_error::malformed);
-  Data = Data.substr(Pad);
-  BinaryCoverageReader::FuncRecordsStorage CoverageRecords =
-      MemoryBuffer::getMemBuffer(Data);
-
-  // Some extra checking.
-  if (CoverageMapping.size() < sizeof(CovMapHeader))
-    return make_error<CoverageMapError>(coveragemap_error::truncated);
-  auto const *CovHeader =
-      reinterpret_cast<const CovMapHeader *>(CoverageMapping.data());
+  auto const *CovHeader = reinterpret_cast<const CovMapHeader *>(
+      Data.substr(0, sizeof(CovMapHeader)).data());
   CovMapVersion Version =
       (CovMapVersion)CovHeader->getVersion<support::endianness::little>();
+  StringRef CoverageMapping;
+  BinaryCoverageReader::FuncRecordsStorage CoverageRecords;
   if (Version < CovMapVersion::Version4) {
-    if (CoverageRecords->getBufferSize() != 0)
-      return make_error<CoverageMapError>(coveragemap_error::malformed);
+    CoverageMapping = Data;
+    if (CoverageMapping.empty())
+      return make_error<CoverageMapError>(coveragemap_error::truncated);
+    CoverageRecords = MemoryBuffer::getMemBuffer("");
   } 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);
+    CoverageRecords = MemoryBuffer::getMemBuffer(Data.substr(Pad));
     if (CoverageRecords->getBufferSize() == 0)
       return make_error<CoverageMapError>(coveragemap_error::truncated);
   }
-
   return BinaryCoverageReader::createCoverageReaderFromBuffer(
       CoverageMapping, std::move(CoverageRecords), std::move(ProfileNames),
       BytesInAddress, Endian, CompilationDir);