5 files changed, 40 insertions, 3 deletions
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 1a85852d5f8..eb16608ad1e 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -738,6 +738,12 @@ lltok::Kind LLLexer::LexIdentifier() {
   INSTKEYWORD(landingpad,     LandingPad);
 #undef INSTKEYWORD
 
+  if (Len >= strlen("DW_TAG_") &&
+      !memcmp(StartChar, "DW_TAG_", strlen("DW_TAG_"))) {
+    StrVal.assign(StartChar, CurPtr);
+    return lltok::DwarfTag;
+  }
+
   // Check for [us]0x[0-9A-Fa-f]+ which are Hexadecimal constant generated by
   // the CFE to avoid forcing it to deal with 64-bit numbers.
   if ((TokStart[0] == 'u' || TokStart[0] == 's') &&
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 8ef8d664457..1f5087c152c 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -24,6 +24,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/ValueSymbolTable.h"
+#include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/raw_ostream.h"
@@ -2936,6 +2937,28 @@ bool LLParser::ParseMDField(LocTy Loc, StringRef Name,
   return false;
 }
 
+bool LLParser::ParseMDField(LocTy Loc, StringRef Name, DwarfTagField &Result) {
+  if (Lex.getKind() == lltok::APSInt)
+    return ParseMDField(Loc, Name,
+                        static_cast<MDUnsignedField<uint32_t> &>(Result));
+
+  if (Result.Seen)
+    return Error(Loc,
+                 "field '" + Name + "' cannot be specified more than once");
+
+  if (Lex.getKind() != lltok::DwarfTag)
+    return TokError("expected DWARF tag");
+
+  unsigned Tag = dwarf::getTag(Lex.getStrVal());
+  if (Tag == dwarf::DW_TAG_invalid)
+    return TokError("invalid DWARF tag" + Twine(" '") + Lex.getStrVal() + "'");
+  assert(Tag < 1u << 16 && "Expected valid DWARF tag");
+
+  Result.assign(Tag);
+  Lex.Lex();
+  return false;
+}
+
 bool LLParser::ParseMDField(LocTy Loc, StringRef Name, MDField &Result) {
   Metadata *MD;
   if (ParseMetadata(MD, nullptr))
@@ -3056,7 +3079,7 @@ bool LLParser::ParseMDLocation(MDNode *&Result, bool IsDistinct) {
 ///   ::= !GenericDebugNode(tag: 15, header: "...", operands: {...})
 bool LLParser::ParseGenericDebugNode(MDNode *&Result, bool IsDistinct) {
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
-  REQUIRED(tag, MDUnsignedField<uint32_t>, (0, ~0u >> 16));                    \
+  REQUIRED(tag, DwarfTagField, );                                              \
   OPTIONAL(header, MDStringField, );                                           \
   OPTIONAL(operands, MDFieldList, );
   PARSE_MD_FIELDS();
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index 6e410d05cd2..240fb608138 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -102,6 +102,9 @@ namespace llvm {
                     NumTy Max = std::numeric_limits<NumTy>::max())
         : ImplTy(Default), Max(Max) {}
   };
+  struct DwarfTagField : public MDUnsignedField<uint32_t> {
+    DwarfTagField() : MDUnsignedField<uint32_t>(0, ~0u >> 16) {}
+  };
   struct MDField : public MDFieldImpl<Metadata *> {
     MDField() : ImplTy(nullptr) {}
   };
@@ -427,6 +430,7 @@ namespace llvm {
 
     bool ParseMDField(LocTy Loc, StringRef Name,
                       MDUnsignedField<uint32_t> &Result);
+    bool ParseMDField(LocTy Loc, StringRef Name, DwarfTagField &Result);
     bool ParseMDField(LocTy Loc, StringRef Name, MDField &Result);
     bool ParseMDField(LocTy Loc, StringRef Name, MDStringField &Result);
     bool ParseMDField(LocTy Loc, StringRef Name, MDFieldList &Result);
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 5b3463bf4ab..4e5af1e89bd 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -198,6 +198,7 @@ namespace lltok {
     LocalVar,          // %foo %"foo"
     MetadataVar,       // !foo
     StringConstant,    // "foo"
+    DwarfTag,          // DW_TAG_foo (includes "DW_TAG_")
 
     // Type valued tokens (TyVal).
     Type,
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index ba1c5260074..46f26c579ac 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1291,8 +1291,11 @@ static void writeGenericDebugNode(raw_ostream &Out, const GenericDebugNode *N,
                                   SlotTracker *Machine, const Module *Context) {
   Out << "!GenericDebugNode(";
   FieldSeparator FS;
-  // Always output the line, since 0 is a relevant and important value for it.
-  Out << FS << "tag: " << N->getTag();
+  Out << FS << "tag: ";
+  if (const char *Tag = dwarf::TagString(N->getTag()))
+    Out << Tag;
+  else
+    Out << N->getTag();
   if (!N->getHeader().empty()) {
     Out << FS << "header: \"";
     PrintEscapedString(N->getHeader(), Out);