[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

4 files changed, 41 insertions, 17 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;
 }
diff --git a/llvm/lib/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.cpp b/llvm/lib/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.cpp
index c54fb2d784a..a908e7df28b 100644
--- a/llvm/lib/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.cpp
+++ b/llvm/lib/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.cpp
@@ -10,7 +10,9 @@
 #include "llvm/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.h"
 
 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
+#include "llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h"
 #include "llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
 
 using namespace llvm;
 using namespace llvm::codeview;
@@ -55,9 +57,10 @@ bool ModuleDebugInlineeLineFragmentRef::hasExtraFiles() const {
 }
 
 ModuleDebugInlineeLineFragment::ModuleDebugInlineeLineFragment(
+    ModuleDebugFileChecksumFragment &Checksums, StringTable &Strings,
     bool HasExtraFiles)
     : ModuleDebugFragment(ModuleDebugFragmentKind::InlineeLines),
-      HasExtraFiles(HasExtraFiles) {}
+      Checksums(Checksums), Strings(Strings), HasExtraFiles(HasExtraFiles) {}
 
 uint32_t ModuleDebugInlineeLineFragment::calculateSerializedLength() {
   // 4 bytes for the signature
@@ -100,18 +103,22 @@ Error ModuleDebugInlineeLineFragment::commit(BinaryStreamWriter &Writer) {
   return Error::success();
 }
 
-void ModuleDebugInlineeLineFragment::addExtraFile(uint32_t FileOffset) {
+void ModuleDebugInlineeLineFragment::addExtraFile(StringRef FileName) {
+  uint32_t Offset = Checksums.mapChecksumOffset(FileName);
+
   auto &Entry = Entries.back();
-  Entry.ExtraFiles.push_back(ulittle32_t(FileOffset));
+  Entry.ExtraFiles.push_back(ulittle32_t(Offset));
   ++ExtraFileCount;
 }
 
 void ModuleDebugInlineeLineFragment::addInlineSite(TypeIndex FuncId,
-                                                   uint32_t FileOffset,
+                                                   StringRef FileName,
                                                    uint32_t SourceLine) {
+  uint32_t Offset = Checksums.mapChecksumOffset(FileName);
+
   Entries.emplace_back();
   auto &Entry = Entries.back();
-  Entry.Header.FileID = FileOffset;
+  Entry.Header.FileID = Offset;
   Entry.Header.SourceLineNum = SourceLine;
   Entry.Header.Inlinee = FuncId;
 }
diff --git a/llvm/lib/DebugInfo/CodeView/ModuleDebugLineFragment.cpp b/llvm/lib/DebugInfo/CodeView/ModuleDebugLineFragment.cpp
index 103010ca283..fdba1147f0b 100644
--- a/llvm/lib/DebugInfo/CodeView/ModuleDebugLineFragment.cpp
+++ b/llvm/lib/DebugInfo/CodeView/ModuleDebugLineFragment.cpp
@@ -10,7 +10,9 @@
 #include "llvm/DebugInfo/CodeView/ModuleDebugLineFragment.h"
 
 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
+#include "llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h"
 #include "llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
 
 using namespace llvm;
 using namespace llvm::codeview;
@@ -65,11 +67,15 @@ bool ModuleDebugLineFragmentRef::hasColumnInfo() const {
   return !!(Header->Flags & LF_HaveColumns);
 }
 
-ModuleDebugLineFragment::ModuleDebugLineFragment()
-    : ModuleDebugFragment(ModuleDebugFragmentKind::Lines) {}
+ModuleDebugLineFragment::ModuleDebugLineFragment(
+    ModuleDebugFileChecksumFragment &Checksums, StringTable &Strings)
+    : ModuleDebugFragment(ModuleDebugFragmentKind::Lines), Checksums(Checksums),
+      Strings(Strings) {}
 
-void ModuleDebugLineFragment::createBlock(uint32_t ChecksumBufferOffset) {
-  Blocks.emplace_back(ChecksumBufferOffset);
+void ModuleDebugLineFragment::createBlock(StringRef FileName) {
+  uint32_t Offset = Checksums.mapChecksumOffset(FileName);
+
+  Blocks.emplace_back(Offset);
 }
 
 void ModuleDebugLineFragment::addLineInfo(uint32_t Offset,
diff --git a/llvm/lib/DebugInfo/CodeView/StringTable.cpp b/llvm/lib/DebugInfo/CodeView/StringTable.cpp
index f496854ffaf..21f11204686 100644
--- a/llvm/lib/DebugInfo/CodeView/StringTable.cpp
+++ b/llvm/lib/DebugInfo/CodeView/StringTable.cpp
@@ -63,3 +63,9 @@ Error StringTable::commit(BinaryStreamWriter &Writer) const {
 }
 
 uint32_t StringTable::size() const { return Strings.size(); }
+
+uint32_t StringTable::getStringId(StringRef S) const {
+  auto P = Strings.find(S);
+  assert(P != Strings.end());
+  return P->second;
+}