[CodeView] Add support for emitting column information

Column information is present in CodeView when the line table subsection
has bit 0 set to 1 in it's flags field.  The column information is
represented as a pair of 16-bit quantities: a starting and ending
column.  This information is present at the end of the chunk, after all
the line-PC pairs.

llvm-svn: 241764

1 files changed, 14 insertions, 6 deletions

diff --git a/llvm/tools/llvm-readobj/COFFDumper.cpp b/llvm/tools/llvm-readobj/COFFDumper.cpp
index 91a4435d848..c6ff1c4dd21 100644
--- a/llvm/tools/llvm-readobj/COFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFDumper.cpp
@@ -585,7 +585,11 @@ void COFFDumper::printCodeViewDebugInfo(const SectionRef &Section) {
     W.printString("FunctionName", Name);
 
     DataExtractor DE(FunctionLineTables[Name], true, 4);
-    uint32_t Offset = 8;  // Skip relocations.
+    uint32_t Offset = 6;  // Skip relocations.
+    uint16_t Flags = DE.getU16(&Offset);
+    W.printHex("Flags", Flags);
+    bool HasColumnInformation =
+        Flags & COFF::DEBUG_LINE_TABLES_HAVE_COLUMN_RECORDS;
     uint32_t FunctionSize = DE.getU32(&Offset);
     W.printHex("CodeSize", FunctionSize);
     while (DE.isValidOffset(Offset)) {
@@ -595,11 +599,6 @@ void COFFDumper::printCodeViewDebugInfo(const SectionRef &Section) {
       uint32_t OffsetInIndex = DE.getU32(&Offset),
                SegmentLength   = DE.getU32(&Offset),
                FullSegmentSize = DE.getU32(&Offset);
-      if (FullSegmentSize != 12 + 8 * SegmentLength) {
-        error(object_error::parse_failed);
-        return;
-      }
-
       uint32_t FilenameOffset;
       {
         DataExtractor SDE(CVFileIndexToStringOffsetTable, true, 4);
@@ -636,6 +635,15 @@ void COFFDumper::printCodeViewDebugInfo(const SectionRef &Section) {
         format("+0x%X", PC).snprint(Buffer, 32);
         W.printNumber(Buffer, LineNumber);
       }
+      if (HasColumnInformation) {
+        for (unsigned J = 0; J != SegmentLength && DE.isValidOffset(Offset);
+             ++J) {
+          uint16_t ColStart = DE.getU16(&Offset);
+          W.printNumber("ColStart", ColStart);
+          uint16_t ColEnd = DE.getU16(&Offset);
+          W.printNumber("ColEnd", ColEnd);
+        }
+      }
     }
   }
 }