[CodeView] Fix off-by-one error in def range gap emission

Also fixes a much worse bug where we emitted the wrong gap size for the
def range uncovered by the test for this issue.

Fixes PR31726.

llvm-svn: 292949

1 files changed, 6 insertions, 6 deletions

diff --git a/llvm/lib/MC/MCCodeView.cpp b/llvm/lib/MC/MCCodeView.cpp
index 3773542..99a5c11 100644
--- a/llvm/lib/MC/MCCodeView.cpp
+++ b/llvm/lib/MC/MCCodeView.cpp
@@ -509,17 +509,17 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
       // are artificially constructing.
       size_t RecordSize = FixedSizePortion.size() +
                           sizeof(LocalVariableAddrRange) + 4 * NumGaps;
-      // Write out the recrod size.
-      support::endian::Writer<support::little>(OS).write<uint16_t>(RecordSize);
+      // Write out the record size.
+      LEWriter.write<uint16_t>(RecordSize);
       // Write out the fixed size prefix.
       OS << FixedSizePortion;
       // Make space for a fixup that will eventually have a section relative
       // relocation pointing at the offset where the variable becomes live.
       Fixups.push_back(MCFixup::create(Contents.size(), BE, FK_SecRel_4));
-      Contents.resize(Contents.size() + 4); // Fixup for code start.
+      LEWriter.write<uint32_t>(0); // Fixup for code start.
       // Make space for a fixup that will record the section index for the code.
       Fixups.push_back(MCFixup::create(Contents.size(), BE, FK_SecRel_2));
-      Contents.resize(Contents.size() + 2); // Fixup for section index.
+      LEWriter.write<uint16_t>(0); // Fixup for section index.
       // Write down the range's extent.
       LEWriter.write<uint16_t>(Chunk);
 
@@ -529,7 +529,7 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
     } while (RangeSize > 0);
 
     // Emit the gaps afterwards.
-    assert((NumGaps == 0 || Bias < MaxDefRange) &&
+    assert((NumGaps == 0 || Bias <= MaxDefRange) &&
            "large ranges should not have gaps");
     unsigned GapStartOffset = GapAndRangeSizes[I].second;
     for (++I; I != J; ++I) {
@@ -537,7 +537,7 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
       assert(I < GapAndRangeSizes.size());
       std::tie(GapSize, RangeSize) = GapAndRangeSizes[I];
       LEWriter.write<uint16_t>(GapStartOffset);
-      LEWriter.write<uint16_t>(RangeSize);
+      LEWriter.write<uint16_t>(GapSize);
       GapStartOffset += GapSize + RangeSize;
     }
   }