Rely on a single DWARF version instead of having two copies

This patch makes AsmPrinter less reliant on DwarfDebug by relying on the DWARF version in the AsmPrinter's MCStreamer's MCContext. This allows us to remove the redundant DWARF version from DwarfDebug. It also lets us change code that used to access the AsmPrinter's DwarfDebug just to get to the DWARF version by changing the DWARF version accessor on AsmPrinter so that it grabs the version from its MCStreamer's MCContext.

Differential Revision: https://reviews.llvm.org/D27032

llvm-svn: 287839

diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index dd38979..93c3981 100644 (file)
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -149,6 +149,9 @@ public:
   DwarfDebug *getDwarfDebug() { return DD; }
   DwarfDebug *getDwarfDebug() const { return DD; }
 
+  uint16_t getDwarfVersion() const;
+  void setDwarfVersion(uint16_t Version);
+
   bool isPositionIndependent() const;
 
   /// Return true if assembly output should contain comments.

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 74724c2..7f9dc83 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2620,3 +2620,11 @@ void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
   Sleds.emplace_back(
     XRayFunctionEntry{ Sled, CurrentFnSym, Kind, AlwaysInstrument, Fn });
 }
+
+uint16_t AsmPrinter::getDwarfVersion() const {
+  return OutStreamer->getContext().getDwarfVersion();
+}
+
+void AsmPrinter::setDwarfVersion(uint16_t Version) {
+  OutStreamer->getContext().setDwarfVersion(Version);
+}

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
index a6c6373..7efe74f 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -177,7 +177,7 @@ void AsmPrinter::emitDwarfStringOffset(DwarfStringPoolEntryRef S) const {
 /// EmitDwarfRegOp - Emit dwarf register operation.
 void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer,
                                 const MachineLocation &MLoc) const {
-  DebugLocDwarfExpression Expr(getDwarfDebug()->getDwarfVersion(), Streamer);
+  DebugLocDwarfExpression Expr(getDwarfVersion(), Streamer);
   const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo();
   int Reg = MRI->getDwarfRegNum(MLoc.getReg(), false);
   if (Reg < 0) {

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index 75b9a16..afb7e87 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -298,7 +298,7 @@ unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
   case dwarf::DW_FORM_addr:
     return AP->getPointerSize();
   case dwarf::DW_FORM_ref_addr:
-    if (AP->OutStreamer->getContext().getDwarfVersion() == 2)
+    if (AP->getDwarfVersion() == 2)
       return AP->getPointerSize();
     return sizeof(int32_t);
   default: llvm_unreachable("DIE Value form not supported yet");
@@ -466,9 +466,7 @@ unsigned DIEEntry::getRefAddrSize(const AsmPrinter *AP) {
   // specified to be four bytes in the DWARF 32-bit format and eight bytes
   // in the DWARF 64-bit format, while DWARF Version 2 specifies that such
   // references have the same size as an address on the target system.
-  const DwarfDebug *DD = AP->getDwarfDebug();
-  assert(DD && "Expected Dwarf Debug info to be available");
-  if (DD->getDwarfVersion() == 2)
+  if (AP->getDwarfVersion() == 2)
     return AP->getPointerSize();
   return sizeof(int32_t);
 }

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 06641d8..884e03d 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -256,7 +256,7 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
     UseAllLinkageNames = DwarfLinkageNames == AllLinkageNames;
 
   unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
-  DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
+  unsigned DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
                                     : MMI->getModule()->getDwarfVersion();
   // Use dwarf 4 by default if nothing is requested.
   DwarfVersion = DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION;
@@ -1197,7 +1197,7 @@ void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
     Fn = Scope->getFilename();
     Dir = Scope->getDirectory();
     if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
-      if (DwarfVersion >= 4)
+      if (getDwarfVersion() >= 4)
         Discriminator = LBF->getDiscriminator();
 
     unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
@@ -1415,8 +1415,7 @@ static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
                               const DebugLocEntry::Value &Value,
                               unsigned PieceOffsetInBits) {
   DIExpressionCursor ExprCursor(Value.getExpression());
-  DebugLocDwarfExpression DwarfExpr(AP.getDwarfDebug()->getDwarfVersion(),
-                                    Streamer);
+  DebugLocDwarfExpression DwarfExpr(AP.getDwarfVersion(), Streamer);
   // Regular entry.
   if (Value.isInt()) {
     if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
@@ -1467,8 +1466,7 @@ void DebugLocEntry::finalize(const AsmPrinter &AP,
       assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
       if (Offset < PieceOffset) {
         // The DWARF spec seriously mandates pieces with no locations for gaps.
-        DebugLocDwarfExpression Expr(AP.getDwarfDebug()->getDwarfVersion(),
-                                     Streamer);
+        DebugLocDwarfExpression Expr(AP.getDwarfVersion(), Streamer);
         Expr.AddOpPiece(PieceOffset-Offset, 0);
         Offset += PieceOffset-Offset;
       }
@@ -1983,3 +1981,7 @@ void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
     return;
   AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
 }
+
+uint16_t DwarfDebug::getDwarfVersion() const {
+  return Asm->OutStreamer->getContext().getDwarfVersion();
+}

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 7d36fe9..37d03a6 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -254,9 +254,6 @@ class DwarfDebug : public DebugHandlerBase {
   /// Whether to emit all linkage names, or just abstract subprograms.
   bool UseAllLinkageNames;
 
-  /// Version of dwarf we're emitting.
-  unsigned DwarfVersion;
-
   /// DWARF5 Experimental Options
   /// @{
   bool HasDwarfAccelTables;
@@ -515,7 +512,7 @@ public:
   bool useSplitDwarf() const { return HasSplitDwarf; }
 
   /// Returns the Dwarf Version.
-  unsigned getDwarfVersion() const { return DwarfVersion; }
+  uint16_t getDwarfVersion() const;
 
   /// Returns the previous CU that was being updated
   const DwarfCompileUnit *getPrevCU() const { return PrevCU; }

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index a49518a..f97b5de 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -51,7 +51,7 @@ GenerateDwarfTypeUnits("generate-type-units", cl::Hidden,
 
 DIEDwarfExpression::DIEDwarfExpression(const AsmPrinter &AP, DwarfUnit &DU,
                                        DIELoc &DIE)
-    : DwarfExpression(AP.getDwarfDebug()->getDwarfVersion()), AP(AP), DU(DU),
+    : DwarfExpression(AP.getDwarfVersion()), AP(AP), DU(DU),
       DIE(DIE) {}
 
 void DIEDwarfExpression::EmitOp(uint8_t Op, const char* Comment) {