[codeview] Remove custom line info struct in favor of DebugLoc

The only functional change would be that we might emit multiple filename
segments on code like this:

  void f() {
  #include "p1/../t.h"
  #include "p2/../t.h"
  }

I believe these get separate DIFile metadata nodes, but will have the
same canonicalized absolute path. Previously by computing the path up
front and comparing it we would merge the line info segments.

llvm-svn: 257966

1 files changed, 33 insertions, 44 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index d2a8bfeb321..f1716361a1d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -22,20 +22,13 @@ using namespace llvm::codeview;
 
 namespace llvm {
 
-StringRef CodeViewDebug::getFullFilepath(const MDNode *S) {
-  assert(S);
-  assert((isa<DICompileUnit>(S) || isa<DIFile>(S) || isa<DISubprogram>(S) ||
-          isa<DILexicalBlockBase>(S)) &&
-         "Unexpected scope info");
-
-  auto *Scope = cast<DIScope>(S);
-  StringRef Dir = Scope->getDirectory(),
-            Filename = Scope->getFilename();
-  std::string &Filepath =
-      DirAndFilenameToFilepathMap[std::make_pair(Dir, Filename)];
+StringRef CodeViewDebug::getFullFilepath(const DIFile *File) {
+  std::string &Filepath = FileToFilepathMap[File];
   if (!Filepath.empty())
     return Filepath;
 
+  StringRef Dir = File->getDirectory(), Filename = File->getFilename();
+
   // Clang emits directory and relative filename info into the IR, but CodeView
   // operates on full paths.  We could change Clang to emit full paths too, but
   // that would increase the IR size and probably not needed for other users.
@@ -82,36 +75,25 @@ StringRef CodeViewDebug::getFullFilepath(const MDNode *S) {
 }
 
 void CodeViewDebug::maybeRecordLocation(DebugLoc DL,
-                                                const MachineFunction *MF) {
-  const MDNode *Scope = DL.getScope();
+                                        const MachineFunction *MF) {
+  // Skip this instruction if it has the same location as the previous one.
+  if (DL == CurFn->LastLoc)
+    return;
+
+  const DIScope *Scope = DL.get()->getScope();
   if (!Scope)
     return;
-  unsigned LineNumber = DL.getLine();
+
   // Skip this line if it is longer than the maximum we can record.
-  if (LineNumber > COFF::CVL_MaxLineNumber)
+  if (DL.getLine() > COFF::CVL_MaxLineNumber)
     return;
 
-  unsigned ColumnNumber = DL.getCol();
-  // Truncate the column number if it is longer than the maximum we can record.
-  if (ColumnNumber > COFF::CVL_MaxColumnNumber)
-    ColumnNumber = 0;
-
-  StringRef Filename = getFullFilepath(Scope);
-
-  // Skip this instruction if it has the same file:line as the previous one.
-  assert(CurFn);
-  if (!CurFn->Instrs.empty()) {
-    const InstrInfoTy &LastInstr = InstrInfo[CurFn->Instrs.back()];
-    if (LastInstr.Filename == Filename && LastInstr.LineNumber == LineNumber &&
-        LastInstr.ColumnNumber == ColumnNumber)
-      return;
-  }
-  FileNameRegistry.add(Filename);
+  CurFn->LastLoc = DL;
 
   MCSymbol *MCL = Asm->MMI->getContext().createTempSymbol();
   Asm->OutStreamer->EmitLabel(MCL);
   CurFn->Instrs.push_back(MCL);
-  InstrInfo[MCL] = InstrInfoTy(Filename, LineNumber, ColumnNumber);
+  LabelsAndLocs[MCL] = DL;
 }
 
 CodeViewDebug::CodeViewDebug(AsmPrinter *AP)
@@ -195,6 +177,10 @@ static void EmitLabelDiff(MCStreamer &Streamer,
   Streamer.EmitValue(AddrDelta, Size);
 }
 
+static const DIFile *getFileFromLoc(DebugLoc DL) {
+  return DL.get()->getScope()->getFile();
+}
+
 void CodeViewDebug::emitDebugInfoForFunction(const Function *GV) {
   // For each function there is a separate subsection
   // which holds the PC to file:line table.
@@ -258,13 +244,14 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV) {
   // number of the respective instruction that starts a new segment.
   DenseMap<size_t, size_t> FilenameSegmentLengths;
   size_t LastSegmentEnd = 0;
-  StringRef PrevFilename = InstrInfo[FI.Instrs[0]].Filename;
+  const DIFile *PrevFile = getFileFromLoc(LabelsAndLocs[FI.Instrs[0]]);
   for (size_t J = 1, F = FI.Instrs.size(); J != F; ++J) {
-    if (PrevFilename == InstrInfo[FI.Instrs[J]].Filename)
+    const DIFile *CurFile = getFileFromLoc(LabelsAndLocs[FI.Instrs[J]]);
+    if (PrevFile == CurFile)
       continue;
     FilenameSegmentLengths[LastSegmentEnd] = J - LastSegmentEnd;
     LastSegmentEnd = J;
-    PrevFilename = InstrInfo[FI.Instrs[J]].Filename;
+    PrevFile = CurFile;
   }
   FilenameSegmentLengths[LastSegmentEnd] = FI.Instrs.size() - LastSegmentEnd;
 
@@ -297,8 +284,11 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV) {
     for (size_t ColSegI = LastSegmentStart,
                 ColSegEnd = ColSegI + FilenameSegmentLengths[LastSegmentStart];
          ColSegI != ColSegEnd; ++ColSegI) {
-      unsigned ColumnNumber = InstrInfo[FI.Instrs[ColSegI]].ColumnNumber;
-      assert(ColumnNumber <= COFF::CVL_MaxColumnNumber);
+      unsigned ColumnNumber = LabelsAndLocs[FI.Instrs[ColSegI]].getCol();
+      // Truncate the column number if it is longer than the maximum we can
+      // record.
+      if (ColumnNumber > COFF::CVL_MaxColumnNumber)
+        ColumnNumber = 0;
       Asm->EmitInt16(ColumnNumber); // Start column
       Asm->EmitInt16(0);            // End column
     }
@@ -307,22 +297,21 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV) {
 
   for (size_t J = 0, F = FI.Instrs.size(); J != F; ++J) {
     MCSymbol *Instr = FI.Instrs[J];
-    assert(InstrInfo.count(Instr));
+    assert(LabelsAndLocs.count(Instr));
 
     if (FilenameSegmentLengths.count(J)) {
       // We came to a beginning of a new filename segment.
       FinishPreviousChunk();
-      StringRef CurFilename = InstrInfo[FI.Instrs[J]].Filename;
-      assert(FileNameRegistry.Infos.count(CurFilename));
-      size_t IndexInStringTable =
-          FileNameRegistry.Infos[CurFilename].FilenameID;
+      const DIFile *File = getFileFromLoc(LabelsAndLocs[FI.Instrs[J]]);
+      StringRef CurFilename = getFullFilepath(File);
+      size_t IndexInFileTable = FileNameRegistry.add(CurFilename);
       // Each segment starts with the offset of the filename
       // in the string table.
       Asm->OutStreamer->AddComment(
           "Segment for file '" + Twine(CurFilename) + "' begins");
       MCSymbol *FileSegmentBegin = Asm->MMI->getContext().createTempSymbol();
       Asm->OutStreamer->EmitLabel(FileSegmentBegin);
-      Asm->EmitInt32(8 * IndexInStringTable);
+      Asm->EmitInt32(8 * IndexInFileTable);
 
       // Number of PC records in the lookup table.
       size_t SegmentLength = FilenameSegmentLengths[J];
@@ -337,7 +326,7 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV) {
 
     // The first PC with the given linenumber and the linenumber itself.
     EmitLabelDiff(*Asm->OutStreamer, Fn, Instr);
-    uint32_t LineNumber = InstrInfo[Instr].LineNumber;
+    uint32_t LineNumber = LabelsAndLocs[Instr].getLine();
     assert(LineNumber <= COFF::CVL_MaxLineNumber);
     uint32_t LineData = LineNumber | COFF::CVL_IsStatement;
     Asm->EmitInt32(LineData);