[DebugInfo] IR/Bitcode changes for DISubprogram flags.

Packing the flags into one bitcode word will save effort in
adding new flags in the future.

Differential Revision: https://reviews.llvm.org/D54755

llvm-svn: 347806

llvm/include/llvm/IR/DebugInfoFlags.def

@@ -78,8 +78,8 @@ HANDLE_DI_FLAG((1 << 29), Largest)
 // Use this as a zero/initialization value.
 // For example: void foo(DISPFlags Flags = SPFlagZero).
 HANDLE_DISP_FLAG(0, Zero)
-// Virtuality is a two-bit valued field.
-HANDLE_DISP_FLAG(0u, Nonvirtual)
+// Virtuality is a two-bit enum field in the LSB of the word.
+// Values should match DW_VIRTUALITY_*.
 HANDLE_DISP_FLAG(1u, Virtual)
 HANDLE_DISP_FLAG(2u, PureVirtual)
 HANDLE_DISP_FLAG((1u << 2), LocalToUnit)

llvm/include/llvm/IR/DebugInfoMetadata.h

@@ -1620,9 +1620,21 @@ class DISubprogram : public DILocalScope {
 #define HANDLE_DISP_FLAG(ID, NAME) SPFlag##NAME = ID,
 #define DISP_FLAG_LARGEST_NEEDED
 #include "llvm/IR/DebugInfoFlags.def"
-    SPFlagVirtuality = SPFlagNonvirtual | SPFlagVirtual | SPFlagPureVirtual,
+    SPFlagNonvirtual = SPFlagZero,
+    SPFlagVirtuality = SPFlagVirtual | SPFlagPureVirtual,
     LLVM_MARK_AS_BITMASK_ENUM(SPFlagLargest)
   };
+
+  static DISPFlags getFlag(StringRef Flag);
+  static StringRef getFlagString(DISPFlags Flag);
+
+  /// Split up a flags bitfield for easier printing.
+  ///
+  /// Split \c Flags into \c SplitFlags, a vector of its components.  Returns
+  /// any remaining (unrecognized) bits.
+  static DISPFlags splitFlags(DISPFlags Flags,
+                              SmallVectorImpl<DISPFlags> &SplitFlags);
+
   // Helper for converting old bitfields to new flags word.
   static DISPFlags toSPFlags(bool IsLocalToUnit, bool IsDefinition,
                              bool IsOptimized,

llvm/lib/AsmParser/LLLexer.cpp

@@ -905,6 +905,11 @@ lltok::Kind LLLexer::LexIdentifier() {
     return lltok::DIFlag;
   }
 
+  if (Keyword.startswith("DISPFlag")) {
+    StrVal.assign(Keyword.begin(), Keyword.end());
+    return lltok::DISPFlag;
+  }
+
   if (Keyword.startswith("CSK_")) {
     StrVal.assign(Keyword.begin(), Keyword.end());
     return lltok::ChecksumKind;

llvm/lib/AsmParser/LLParser.cpp

@@ -3749,6 +3749,10 @@ struct DIFlagField : public MDFieldImpl<DINode::DIFlags> {
   DIFlagField() : MDFieldImpl(DINode::FlagZero) {}
 };
 
+struct DISPFlagField : public MDFieldImpl<DISubprogram::DISPFlags> {
+  DISPFlagField() : MDFieldImpl(DISubprogram::SPFlagZero) {}
+};
+
 struct MDSignedField : public MDFieldImpl<int64_t> {
   int64_t Min;
   int64_t Max;
@@ -4041,6 +4045,46 @@ bool LLParser::ParseMDField(LocTy Loc, StringRef Name, DIFlagField &Result) {
   return false;
 }
 
+/// DISPFlagField
+///  ::= uint32
+///  ::= DISPFlagVector
+///  ::= DISPFlagVector '|' DISPFlag* '|' uint32
+template <>
+bool LLParser::ParseMDField(LocTy Loc, StringRef Name, DISPFlagField &Result) {
+
+  // Parser for a single flag.
+  auto parseFlag = [&](DISubprogram::DISPFlags &Val) {
+    if (Lex.getKind() == lltok::APSInt && !Lex.getAPSIntVal().isSigned()) {
+      uint32_t TempVal = static_cast<uint32_t>(Val);
+      bool Res = ParseUInt32(TempVal);
+      Val = static_cast<DISubprogram::DISPFlags>(TempVal);
+      return Res;
+    }
+
+    if (Lex.getKind() != lltok::DISPFlag)
+      return TokError("expected debug info flag");
+
+    Val = DISubprogram::getFlag(Lex.getStrVal());
+    if (!Val)
+      return TokError(Twine("invalid subprogram debug info flag '") +
+                      Lex.getStrVal() + "'");
+    Lex.Lex();
+    return false;
+  };
+
+  // Parse the flags and combine them together.
+  DISubprogram::DISPFlags Combined = DISubprogram::SPFlagZero;
+  do {
+    DISubprogram::DISPFlags Val;
+    if (parseFlag(Val))
+      return true;
+    Combined |= Val;
+  } while (EatIfPresent(lltok::bar));
+
+  Result.assign(Combined);
+  return false;
+}
+
 template <>
 bool LLParser::ParseMDField(LocTy Loc, StringRef Name,
                             MDSignedField &Result) {
@@ -4517,8 +4561,8 @@ bool LLParser::ParseDICompileUnit(MDNode *&Result, bool IsDistinct) {
 ///                     isDefinition: true, scopeLine: 8, containingType: !3,
 ///                     virtuality: DW_VIRTUALTIY_pure_virtual,
 ///                     virtualIndex: 10, thisAdjustment: 4, flags: 11,
-///                     isOptimized: false, templateParams: !4, declaration: !5,
-///                     retainedNodes: !6, thrownTypes: !7)
+///                     spFlags: 10, isOptimized: false, templateParams: !4,
+///                     declaration: !5, retainedNodes: !6, thrownTypes: !7)
 bool LLParser::ParseDISubprogram(MDNode *&Result, bool IsDistinct) {
   auto Loc = Lex.getLoc();
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
@@ -4536,21 +4580,26 @@ bool LLParser::ParseDISubprogram(MDNode *&Result, bool IsDistinct) {
   OPTIONAL(virtualIndex, MDUnsignedField, (0, UINT32_MAX));                    \
   OPTIONAL(thisAdjustment, MDSignedField, (0, INT32_MIN, INT32_MAX));          \
   OPTIONAL(flags, DIFlagField, );                                              \
+  OPTIONAL(spFlags, DISPFlagField, );                                          \
   OPTIONAL(isOptimized, MDBoolField, );                                        \
   OPTIONAL(unit, MDField, );                                                   \
   OPTIONAL(templateParams, MDField, );                                         \
   OPTIONAL(declaration, MDField, );                                            \
-  OPTIONAL(retainedNodes, MDField, );                                              \
+  OPTIONAL(retainedNodes, MDField, );                                          \
   OPTIONAL(thrownTypes, MDField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
-  if (isDefinition.Val && !IsDistinct)
+  // An explicit spFlags field takes precedence over individual fields in
+  // older IR versions.
+  DISubprogram::DISPFlags SPFlags =
+      spFlags.Seen ? spFlags.Val
+                   : DISubprogram::toSPFlags(isLocal.Val, isDefinition.Val,
+                                             isOptimized.Val, virtuality.Val);
+  if ((SPFlags & DISubprogram::SPFlagDefinition) && !IsDistinct)
     return Lex.Error(
         Loc,
-        "missing 'distinct', required for !DISubprogram when 'isDefinition'");
-  DISubprogram::DISPFlags SPFlags = DISubprogram::toSPFlags(
-      isLocal.Val, isDefinition.Val, isOptimized.Val, virtuality.Val);
+        "missing 'distinct', required for !DISubprogram that is a Definition");
   Result = GET_OR_DISTINCT(
       DISubprogram,
       (Context, scope.Val, name.Val, linkageName.Val, file.Val, line.Val,

llvm/lib/AsmParser/LLToken.h

@@ -442,6 +442,7 @@ enum Kind {
   NameTableKind,    // GNU
   DwarfOp,          // DW_OP_foo
   DIFlag,           // DIFlagFoo
+  DISPFlag,         // DISPFlagFoo
   DwarfMacinfo,     // DW_MACINFO_foo
   ChecksumKind,     // CSK_foo
 

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

@@ -1406,23 +1406,43 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     if (Record.size() < 18 || Record.size() > 21)
       return error("Invalid record");
 
-    IsDistinct =
-        (Record[0] & 1) || Record[8]; // All definitions should be distinct.
+    bool HasSPFlags = Record[0] & 4;
+    DISubprogram::DISPFlags SPFlags =
+        HasSPFlags
+            ? static_cast<DISubprogram::DISPFlags>(Record[9])
+            : DISubprogram::toSPFlags(
+                  /*IsLocalToUnit=*/Record[7], /*IsDefinition=*/Record[8],
+                  /*IsOptimized=*/Record[14], /*Virtuality=*/Record[11]);
+
+    // All definitions should be distinct.
+    IsDistinct = (Record[0] & 1) || (SPFlags & DISubprogram::SPFlagDefinition);
     // Version 1 has a Function as Record[15].
     // Version 2 has removed Record[15].
     // Version 3 has the Unit as Record[15].
     // Version 4 added thisAdjustment.
-    bool HasUnit = Record[0] >= 2;
-    if (HasUnit && Record.size() < 19)
+    // Version 5 repacked flags into DISPFlags, changing many element numbers.
+    bool HasUnit = Record[0] & 2;
+    if (!HasSPFlags && HasUnit && Record.size() < 19)
       return error("Invalid record");
-    Metadata *CUorFn = getMDOrNull(Record[15]);
-    unsigned Offset = Record.size() >= 19 ? 1 : 0;
-    bool HasFn = Offset && !HasUnit;
-    bool HasThisAdj = Record.size() >= 20;
-    bool HasThrownTypes = Record.size() >= 21;
-    DISubprogram::DISPFlags SPFlags = DISubprogram::toSPFlags(
-        /*IsLocalToUnit=*/Record[7], /*IsDefinition=*/Record[8],
-        /*IsOptimized=*/Record[14], /*Virtuality=*/Record[11]);
+    if (HasSPFlags && !HasUnit)
+      return error("Invalid record");
+    // Accommodate older formats.
+    bool HasFn = false;
+    bool HasThisAdj = true;
+    bool HasThrownTypes = true;
+    unsigned OffsetA = 0;
+    unsigned OffsetB = 0;
+    if (!HasSPFlags) {
+      OffsetA = 2;
+      OffsetB = 2;
+      if (Record.size() >= 19) {
+        HasFn = !HasUnit;
+        OffsetB++;
+      }
+      HasThisAdj = Record.size() >= 20;
+      HasThrownTypes = Record.size() >= 21;
+    }
+    Metadata *CUorFn = getMDOrNull(Record[12 + OffsetB]);
     DISubprogram *SP = GET_OR_DISTINCT(
         DISubprogram,
         (Context,
@@ -1432,17 +1452,18 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
          getMDOrNull(Record[4]),                            // file
          Record[5],                                         // line
          getMDOrNull(Record[6]),                            // type
-         Record[9],                                         // scopeLine
-         getDITypeRefOrNull(Record[10]),                    // containingType
-         Record[12],                                        // virtualIndex
-         HasThisAdj ? Record[19] : 0,                       // thisAdjustment
-         static_cast<DINode::DIFlags>(Record[13]),          // flags
+         Record[7 + OffsetA],                               // scopeLine
+         getDITypeRefOrNull(Record[8 + OffsetA]),           // containingType
+         Record[10 + OffsetA],                              // virtualIndex
+         HasThisAdj ? Record[16 + OffsetB] : 0,             // thisAdjustment
+         static_cast<DINode::DIFlags>(Record[11 + OffsetA]),// flags
          SPFlags,                                           // SPFlags
          HasUnit ? CUorFn : nullptr,                        // unit
-         getMDOrNull(Record[15 + Offset]),                  // templateParams
-         getMDOrNull(Record[16 + Offset]),                  // declaration
-         getMDOrNull(Record[17 + Offset]),                  // retainedNodes
-         HasThrownTypes ? getMDOrNull(Record[20]) : nullptr // thrownTypes
+         getMDOrNull(Record[13 + OffsetB]),                 // templateParams
+         getMDOrNull(Record[14 + OffsetB]),                 // declaration
+         getMDOrNull(Record[15 + OffsetB]),                 // retainedNodes
+         HasThrownTypes ? getMDOrNull(Record[17 + OffsetB])
+                        : nullptr                           // thrownTypes
          ));
     MetadataList.assignValue(SP, NextMetadataNo);
     NextMetadataNo++;

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -1633,22 +1633,20 @@ void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
-  uint64_t HasUnitFlag = 1 << 1;
-  Record.push_back(N->isDistinct() | HasUnitFlag);
+  const uint64_t HasUnitFlag = 1 << 1;
+  const uint64_t HasSPFlagsFlag = 1 << 2;
+  Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
   Record.push_back(N->getLine());
   Record.push_back(VE.getMetadataOrNullID(N->getType()));
-  Record.push_back(N->isLocalToUnit());
-  Record.push_back(N->isDefinition());
   Record.push_back(N->getScopeLine());
   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
-  Record.push_back(N->getVirtuality());
+  Record.push_back(N->getSPFlags());
   Record.push_back(N->getVirtualIndex());
   Record.push_back(N->getFlags());
-  Record.push_back(N->isOptimized());
   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));

llvm/lib/IR/AsmWriter.cpp

@@ -1607,6 +1607,7 @@ struct MDFieldPrinter {
   void printInt(StringRef Name, IntTy Int, bool ShouldSkipZero = true);
   void printBool(StringRef Name, bool Value, Optional<bool> Default = None);
   void printDIFlags(StringRef Name, DINode::DIFlags Flags);
+  void printDISPFlags(StringRef Name, DISubprogram::DISPFlags Flags);
   template <class IntTy, class Stringifier>
   void printDwarfEnum(StringRef Name, IntTy Value, Stringifier toString,
                       bool ShouldSkipZero = true);
@@ -1705,6 +1706,30 @@ void MDFieldPrinter::printDIFlags(StringRef Name, DINode::DIFlags Flags) {
     Out << FlagsFS << Extra;
 }
 
+void MDFieldPrinter::printDISPFlags(StringRef Name,
+                                    DISubprogram::DISPFlags Flags) {
+  // Always print this field, because no flags in the IR at all will be
+  // interpreted as old-style isDefinition: true.
+  Out << FS << Name << ": ";
+
+  if (!Flags) {
+    Out << 0;
+    return;
+  }
+
+  SmallVector<DISubprogram::DISPFlags, 8> SplitFlags;
+  auto Extra = DISubprogram::splitFlags(Flags, SplitFlags);
+
+  FieldSeparator FlagsFS(" | ");
+  for (auto F : SplitFlags) {
+    auto StringF = DISubprogram::getFlagString(F);
+    assert(!StringF.empty() && "Expected valid flag");
+    Out << FlagsFS << StringF;
+  }
+  if (Extra || SplitFlags.empty())
+    Out << FlagsFS << Extra;
+}
+
 void MDFieldPrinter::printEmissionKind(StringRef Name,
                                        DICompileUnit::DebugEmissionKind EK) {
   Out << FS << Name << ": " << DICompileUnit::emissionKindString(EK);
@@ -1925,18 +1950,14 @@ static void writeDISubprogram(raw_ostream &Out, const DISubprogram *N,
   Printer.printMetadata("file", N->getRawFile());
   Printer.printInt("line", N->getLine());
   Printer.printMetadata("type", N->getRawType());
-  Printer.printBool("isLocal", N->isLocalToUnit());
-  Printer.printBool("isDefinition", N->isDefinition());
   Printer.printInt("scopeLine", N->getScopeLine());
   Printer.printMetadata("containingType", N->getRawContainingType());
-  Printer.printDwarfEnum("virtuality", N->getVirtuality(),
-                         dwarf::VirtualityString);
   if (N->getVirtuality() != dwarf::DW_VIRTUALITY_none ||
       N->getVirtualIndex() != 0)
     Printer.printInt("virtualIndex", N->getVirtualIndex(), false);
   Printer.printInt("thisAdjustment", N->getThisAdjustment());
   Printer.printDIFlags("flags", N->getFlags());
-  Printer.printBool("isOptimized", N->isOptimized());
+  Printer.printDISPFlags("spFlags", N->getSPFlags());
   Printer.printMetadata("unit", N->getRawUnit());
   Printer.printMetadata("templateParams", N->getRawTemplateParams());
   Printer.printMetadata("declaration", N->getRawDeclaration());

llvm/lib/IR/DebugInfoMetadata.cpp

@@ -542,6 +542,40 @@ DILocalScope *DILocalScope::getNonLexicalBlockFileScope() const {
   return const_cast<DILocalScope *>(this);
 }
 
+DISubprogram::DISPFlags DISubprogram::getFlag(StringRef Flag) {
+  return StringSwitch<DISPFlags>(Flag)
+#define HANDLE_DISP_FLAG(ID, NAME) .Case("DISPFlag" #NAME, SPFlag##NAME)
+#include "llvm/IR/DebugInfoFlags.def"
+      .Default(SPFlagZero);
+}
+
+StringRef DISubprogram::getFlagString(DISPFlags Flag) {
+  switch (Flag) {
+  case SPFlagVirtuality: // Appease a warning.
+    return "";
+#define HANDLE_DISP_FLAG(ID, NAME)                                             \
+  case SPFlag##NAME:                                                           \
+    return "DISPFlag" #NAME;
+#include "llvm/IR/DebugInfoFlags.def"
+  }
+  return "";
+}
+
+DISubprogram::DISPFlags
+DISubprogram::splitFlags(DISPFlags Flags,
+                         SmallVectorImpl<DISPFlags> &SplitFlags) {
+  // Multi-bit fields can require special handling. In our case, however, the
+  // only multi-bit field is virtuality, and all its values happen to be
+  // single-bit values, so the right behavior just falls out.
+#define HANDLE_DISP_FLAG(ID, NAME)                                             \
+  if (DISPFlags Bit = Flags & SPFlag##NAME) {                                  \
+    SplitFlags.push_back(Bit);                                                 \
+    Flags &= ~Bit;                                                             \
+  }
+#include "llvm/IR/DebugInfoFlags.def"
+  return Flags;
+}
+
 DISubprogram *DISubprogram::getImpl(
     LLVMContext &Context, Metadata *Scope, MDString *Name,
     MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,