[CodeView] Use actual strings for dealing with checksums and lines.

The raw CodeView format references strings by "offsets", but it's
confusing what table the offset refers to.  In the case of line
number information, it's an offset into a buffer of records,
and an indirection is required to get another offset into a
different table to find the final string.  And in the case of
checksum information, there is no indirection, and the offset
refers directly to the location of the string in another buffer.

This would be less confusing if we always just referred to the
strings by their value, and have the library be smart enough
to correctly resolve the offsets on its own from the right
location.

This patch makes that possible.  When either reading or writing,
all the user deals with are strings, and the library does the
appropriate translations behind the scenes.

llvm-svn: 302053

1 files changed, 13 insertions, 8 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp b/llvm/lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
index 87763248391..42f0afc3e2d 100644
--- a/llvm/lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
+++ b/llvm/lib/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.cpp
@@ -10,6 +10,7 @@
 #include "llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h"
 
 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
 #include "llvm/Support/BinaryStreamReader.h"
 
 using namespace llvm;
@@ -49,10 +50,12 @@ Error ModuleDebugFileChecksumFragmentRef::initialize(
   return Error::success();
 }
 
-ModuleDebugFileChecksumFragment::ModuleDebugFileChecksumFragment()
-    : ModuleDebugFragment(ModuleDebugFragmentKind::FileChecksums) {}
+ModuleDebugFileChecksumFragment::ModuleDebugFileChecksumFragment(
+    StringTable &Strings)
+    : ModuleDebugFragment(ModuleDebugFragmentKind::FileChecksums),
+      Strings(Strings) {}
 
-void ModuleDebugFileChecksumFragment::addChecksum(uint32_t StringTableOffset,
+void ModuleDebugFileChecksumFragment::addChecksum(StringRef FileName,
                                                   FileChecksumKind Kind,
                                                   ArrayRef<uint8_t> Bytes) {
   FileChecksumEntry Entry;
@@ -61,13 +64,14 @@ void ModuleDebugFileChecksumFragment::addChecksum(uint32_t StringTableOffset,
     ::memcpy(Copy, Bytes.data(), Bytes.size());
     Entry.Checksum = makeArrayRef(Copy, Bytes.size());
   }
-  Entry.FileNameOffset = StringTableOffset;
+
+  Entry.FileNameOffset = Strings.insert(FileName);
   Entry.Kind = Kind;
   Checksums.push_back(Entry);
 
   // This maps the offset of this string in the string table to the offset
   // of this checksum entry in the checksum buffer.
-  OffsetMap[StringTableOffset] = SerializedSize;
+  OffsetMap[Entry.FileNameOffset] = SerializedSize;
   assert(SerializedSize % 4 == 0);
 
   uint32_t Len = alignTo(sizeof(FileChecksumEntryHeader) + Bytes.size(), 4);
@@ -94,9 +98,10 @@ Error ModuleDebugFileChecksumFragment::commit(BinaryStreamWriter &Writer) {
   return Error::success();
 }
 
-uint32_t ModuleDebugFileChecksumFragment::mapChecksumOffset(
-    uint32_t StringTableOffset) const {
-  auto Iter = OffsetMap.find(StringTableOffset);
+uint32_t
+ModuleDebugFileChecksumFragment::mapChecksumOffset(StringRef FileName) const {
+  uint32_t Offset = Strings.getStringId(FileName);
+  auto Iter = OffsetMap.find(Offset);
   assert(Iter != OffsetMap.end());
   return Iter->second;
 }