Add column, DW_AT_artificial & llvm-coro-suspension point

vogelsgesang · vogelsgesang · commit 4ebf6a4a9092 · 2025-06-28T14:45:42.000Z
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -5293,7 +5293,7 @@ void CGDebugInfo::EmitLabel(const LabelDecl *D, CGBuilderTy &Builder) {
 
   // Create the descriptor for the label.
   auto *L =
-      DBuilder.createLabel(Scope, Name, Unit, Line, CGM.getLangOpts().Optimize);
+      DBuilder.createLabel(Scope, Name, Unit, Line, Column, /*IsArtificial=*/false, /*CoroSuspendIdx=*/std::nullopt, CGM.getLangOpts().Optimize);
 
   // Insert an llvm.dbg.label into the current block.
   DBuilder.insertLabel(L,
diff --git a/clang/test/CodeGen/debug-label-inline.c b/clang/test/CodeGen/debug-label-inline.c
@@ -23,6 +23,6 @@ int f2(void) {
 
 // CHECK: distinct !DISubprogram(name: "f1", {{.*}}, retainedNodes: [[ELEMENTS:!.*]])
 // CHECK: [[ELEMENTS]] = !{{{.*}}, [[LABEL_METADATA]]}
-// CHECK: [[LABEL_METADATA]] = !DILabel({{.*}}, name: "top", {{.*}}, line: 8)
+// CHECK: [[LABEL_METADATA]] = !DILabel({{.*}}, name: "top", {{.*}}, line: 8, column: 1)
 // CHECK: [[INLINEDAT:!.*]] = distinct !DILocation(line: 18,
 // CHECK: [[LABEL_LOCATION]] = !DILocation(line: 8, {{.*}}, inlinedAt: [[INLINEDAT]])
diff --git a/clang/test/CodeGen/debug-label.c b/clang/test/CodeGen/debug-label.c
@@ -12,5 +12,5 @@ int f1(int a, int b) {
   return sum;
 }
 
-// CHECK: [[LABEL_METADATA]] = !DILabel({{.*}}, name: "top", {{.*}}, line: 9)
+// CHECK: [[LABEL_METADATA]] = !DILabel({{.*}}, name: "top", {{.*}}, line: 9, column: 1)
 // CHECK: [[LABEL_LOCATION]] = !DILocation(line: 9,
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
@@ -6975,16 +6975,22 @@ appear in the included source file.
 DILabel
 """""""
 
-``DILabel`` nodes represent labels within a :ref:`DISubprogram`. All fields of
-a ``DILabel`` are mandatory. The ``scope:`` field must be one of either a
-:ref:`DILexicalBlockFile`, a :ref:`DILexicalBlock`, or a :ref:`DISubprogram`.
-The ``name:`` field is the label identifier. The ``file:`` field is the
-:ref:`DIFile` the label is present in. The ``line:`` field is the source line
+``DILabel`` nodes represent labels within a :ref:`DISubprogram`. The ``scope:``
+field must be one of either a :ref:`DILexicalBlockFile`, a
+:ref:`DILexicalBlock`, or a :ref:`DISubprogram`. The ``name:`` field is the
+label identifier. The ``file:`` field is the :ref:`DIFile` the label is
+present in. The ``line:`` and ``column:`` field are the source line and column
 within the file where the label is declared.
 
+Furthermore, a label can be marked as artificial, i.e. compiler-generated,
+using ``isArtificial:``. Such artitificial labels are generated, e.g., by
+the ``CoroSplit`` pass. In addition, the ``CoroSplit`` pass also uses the
+``coroSuspendIdx:`` field to identify the coroutine suspend points.
+
 .. code-block:: text
 
-  !2 = !DILabel(scope: !0, name: "foo", file: !1, line: 7)
+  !2 = !DILabel(scope: !0, name: "foo", file: !1, line: 7, column: 4)
+  !3 = !DILabel(scope: !0, name: "__coro_resume_3", file: !1, line: 9, column: 3, isArtificial: true, coroSuspendIdx: 3)
 
 DICommonBlock
 """""""""""""
diff --git a/llvm/include/llvm/BinaryFormat/Dwarf.def b/llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -624,6 +624,7 @@ HANDLE_DW_AT(0x3e09, LLVM_ptrauth_authenticates_null_values, 0, LLVM)
 HANDLE_DW_AT(0x3e0a, LLVM_ptrauth_authentication_mode, 0, LLVM)
 HANDLE_DW_AT(0x3e0b, LLVM_num_extra_inhabitants, 0, LLVM)
 HANDLE_DW_AT(0x3e0c, LLVM_stmt_sequence, 0, LLVM)
+HANDLE_DW_AT(0x3e0d, LLVM_coro_suspend_idx, 0, LLVM)
 
 // Apple extensions.
 
diff --git a/llvm/include/llvm/IR/DIBuilder.h b/llvm/include/llvm/IR/DIBuilder.h
@@ -901,7 +901,9 @@ namespace llvm {
     /// \c Scope must be a \a DILocalScope, and thus its scope chain eventually
     /// leads to a \a DISubprogram.
     LLVM_ABI DILabel *createLabel(DIScope *Scope, StringRef Name, DIFile *File,
-                                  unsigned LineNo, bool AlwaysPreserve = false);
+                                  unsigned LineNo, unsigned Column, bool IsArtificial,
+                                  std::optional<unsigned> CoroSuspendIdx,
+                                  bool AlwaysPreserve = false);
 
     /// Create a new descriptor for a parameter variable.
     ///
diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -4104,35 +4104,49 @@ class DILabel : public DINode {
   friend class LLVMContextImpl;
   friend class MDNode;
 
-  DILabel(LLVMContext &C, StorageType Storage, unsigned Line,
+  unsigned Column;
+  std::optional<unsigned> CoroSuspendIdx;
+  bool IsArtificial;
+
+  DILabel(LLVMContext &C, StorageType Storage, unsigned Line, unsigned Column,
+          bool IsArtificial, std::optional<unsigned> CoroSuspendIdx,
           ArrayRef<Metadata *> Ops);
   ~DILabel() = default;
 
   static DILabel *getImpl(LLVMContext &Context, DIScope *Scope, StringRef Name,
-                          DIFile *File, unsigned Line, StorageType Storage,
-                          bool ShouldCreate = true) {
+                          DIFile *File, unsigned Line, unsigned Column,
+                          bool IsArtificial, std::optional<unsigned> CoroSuspendIdx,
+                          StorageType Storage, bool ShouldCreate = true) {
     return getImpl(Context, Scope, getCanonicalMDString(Context, Name), File,
-                   Line, Storage, ShouldCreate);
+                   Line, Column, IsArtificial, CoroSuspendIdx, Storage,
+                   ShouldCreate);
   }
   LLVM_ABI static DILabel *getImpl(LLVMContext &Context, Metadata *Scope,
                                    MDString *Name, Metadata *File,
-                                   unsigned Line, StorageType Storage,
+                                   unsigned Line, unsigned Column,
+                                   bool IsArtificial, std::optional<unsigned> CoroSuspendIdx,
+                                   StorageType Storage,
                                    bool ShouldCreate = true);
 
   TempDILabel cloneImpl() const {
     return getTemporary(getContext(), getScope(), getName(), getFile(),
-                        getLine());
+                        getLine(), getColumn(), isArtificial(),
+                        getCoroSuspendIdx());
   }
 
 public:
   DEFINE_MDNODE_GET(DILabel,
                     (DILocalScope * Scope, StringRef Name, DIFile *File,
-                     unsigned Line),
-                    (Scope, Name, File, Line))
+                     unsigned Line, unsigned Column, bool IsArtificial,
+                     std::optional<unsigned> CoroSuspendIdx),
+                    (Scope, Name, File, Line, Column, IsArtificial,
+                     CoroSuspendIdx))
   DEFINE_MDNODE_GET(DILabel,
                     (Metadata * Scope, MDString *Name, Metadata *File,
-                     unsigned Line),
-                    (Scope, Name, File, Line))
+                     unsigned Line, unsigned Column, bool IsArtificial,
+                     std::optional<unsigned> CoroSuspendIdx),
+                    (Scope, Name, File, Line, Column, IsArtificial,
+                     CoroSuspendIdx))
 
   TempDILabel clone() const { return cloneImpl(); }
 
@@ -4143,8 +4157,11 @@ class DILabel : public DINode {
     return cast_or_null<DILocalScope>(getRawScope());
   }
   unsigned getLine() const { return SubclassData32; }
+  unsigned getColumn() const { return Column; }
   StringRef getName() const { return getStringOperand(1); }
   DIFile *getFile() const { return cast_or_null<DIFile>(getRawFile()); }
+  bool isArtificial() const { return IsArtificial; }
+  std::optional<unsigned> getCoroSuspendIdx() const { return CoroSuspendIdx; }
 
   Metadata *getRawScope() const { return getOperand(0); }
   MDString *getRawName() const { return getOperandAs<MDString>(1); }
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
@@ -6116,18 +6116,23 @@ bool LLParser::parseDILocalVariable(MDNode *&Result, bool IsDistinct) {
 }
 
 /// parseDILabel:
-///   ::= !DILabel(scope: !0, name: "foo", file: !1, line: 7)
+///   ::= !DILabel(scope: !0, name: "foo", file: !1, line: 7, column: 4)
 bool LLParser::parseDILabel(MDNode *&Result, bool IsDistinct) {
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
   REQUIRED(scope, MDField, (/* AllowNull */ false));                           \
   REQUIRED(name, MDStringField, );                                             \
   REQUIRED(file, MDField, );                                                   \
-  REQUIRED(line, LineField, );
+  REQUIRED(line, LineField, );                                                 \
+  OPTIONAL(column, ColumnField, );                                             \
+  OPTIONAL(isArtificial, MDBoolField, );                                       \
+  OPTIONAL(coroSuspendIdx, MDUnsignedField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
+  std::optional<unsigned> CoroSuspendIdx = coroSuspendIdx.Seen ? std::optional<unsigned>(coroSuspendIdx.Val) : std::nullopt;
+
   Result = GET_OR_DISTINCT(DILabel,
-                           (Context, scope.Val, name.Val, file.Val, line.Val));
+                           (Context, scope.Val, name.Val, file.Val, line.Val, column.Val, isArtificial.Val, CoroSuspendIdx));
   return false;
 }
 
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1133,6 +1133,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
     ++NumMDRecordLoaded;
     if (Expected<unsigned> MaybeCode =
             Stream.readRecord(Entry.ID, Record, &Blob)) {
+      // Crashes called from here!
       if (Error Err = parseOneMetadata(Record, MaybeCode.get(), Placeholders,
                                        Blob, NextMetadataNo))
         return Err;
@@ -1319,6 +1320,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     unsigned Size = Record.size();
     NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
     for (unsigned i = 0; i != Size; ++i) {
+      // Crashes here!
       MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
       if (!MD)
         return error("Invalid named metadata: expect fwd ref to MDNode");
@@ -2240,14 +2242,27 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_LABEL: {
-    if (Record.size() != 5)
+    if (Record.size() < 5 || Record.size() > 7)
       return error("Invalid record");
 
     IsDistinct = Record[0] & 1;
+    uint64_t Line = Record[4];
+    uint64_t Column = Record.size() > 5 ? Record[5] : 0;
+    bool IsArtificial = Record[0] & 2;
+    std::optional<unsigned> CoroSuspendIdx;
+    if (Record.size() > 6) {
+      unsigned RawSuspendIdx = Record[6];
+      if (RawSuspendIdx != std::numeric_limits<unsigned>::max()) {
+        if (RawSuspendIdx > (uint64_t)std::numeric_limits<unsigned>::max())
+          return error("CoroSuspendIdx value is too large");
+        CoroSuspendIdx = RawSuspendIdx;
+      }
+    }
+
     MetadataList.assignValue(
         GET_OR_DISTINCT(DILabel, (Context, getMDOrNull(Record[1]),
                                   getMDString(Record[2]),
-                                  getMDOrNull(Record[3]), Record[4])),
+                                  getMDOrNull(Record[3]), Line, Column, IsArtificial, CoroSuspendIdx)),
         NextMetadataNo);
     NextMetadataNo++;
     break;
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -2344,11 +2344,14 @@ void ModuleBitcodeWriter::writeDILocalVariable(
 void ModuleBitcodeWriter::writeDILabel(
     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
     unsigned Abbrev) {
-  Record.push_back((uint64_t)N->isDistinct());
+  uint64_t IsArtificialFlag = uint64_t(N->isArtificial()) << 1;
+  Record.push_back((uint64_t)N->isDistinct() | IsArtificialFlag);
   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
   Record.push_back(N->getLine());
+  Record.push_back(N->getColumn());
+  Record.push_back(N->getCoroSuspendIdx().value_or(std::numeric_limits<uint64_t>::max()));
 
   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
   Record.clear();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -429,7 +429,7 @@ DIE *DwarfCompileUnit::getOrCreateCommonBlock(
   addString(NDie, dwarf::DW_AT_name, Name);
   addGlobalName(Name, NDie, CB->getScope());
   if (CB->getFile())
-    addSourceLine(NDie, CB->getLineNo(), CB->getFile());
+    addSourceLine(NDie, CB->getLineNo(), /*Column*/ 0, CB->getFile());
   if (DIGlobalVariable *V = CB->getDecl())
     getCU().addLocationAttribute(&NDie, V, GlobalExprs);
   return &NDie;
@@ -1404,7 +1404,7 @@ DIE *DwarfCompileUnit::constructImportedEntityDIE(
   else
     EntityDie = getDIE(Entity);
   assert(EntityDie);
-  addSourceLine(*IMDie, Module->getLine(), Module->getFile());
+  addSourceLine(*IMDie, Module->getLine(), /*Column*/ 0, Module->getFile());
   addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
   StringRef Name = Module->getName();
   if (!Name.empty()) {
@@ -1701,6 +1701,11 @@ void DwarfCompileUnit::applyLabelAttributes(const DbgLabel &Label,
     addString(LabelDie, dwarf::DW_AT_name, Name);
   const auto *DILabel = Label.getLabel();
   addSourceLine(LabelDie, DILabel);
+  if (DILabel->isArtificial())
+    addFlag(LabelDie, dwarf::DW_AT_artificial);
+  if (DILabel->getCoroSuspendIdx())
+    addUInt(LabelDie, dwarf::DW_AT_LLVM_coro_suspend_idx, std::nullopt,
+            *DILabel->getCoroSuspendIdx());
 }
 
 /// Add a Dwarf expression attribute data and value.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -442,49 +442,52 @@ void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute,
   addBlock(Die, Attribute, Block->BestForm(), Block);
 }
 
-void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, const DIFile *File) {
+void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, unsigned Column, const DIFile *File) {
   if (Line == 0)
     return;
 
   unsigned FileID = getOrCreateSourceID(File);
   addUInt(Die, dwarf::DW_AT_decl_file, std::nullopt, FileID);
   addUInt(Die, dwarf::DW_AT_decl_line, std::nullopt, Line);
+
+  if (Column != 0)
+    addUInt(Die, dwarf::DW_AT_decl_column, std::nullopt, Column);
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DILocalVariable *V) {
   assert(V);
 
-  addSourceLine(Die, V->getLine(), V->getFile());
+  addSourceLine(Die, V->getLine(), /*Column*/ 0, V->getFile());
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DIGlobalVariable *G) {
   assert(G);
 
-  addSourceLine(Die, G->getLine(), G->getFile());
+  addSourceLine(Die, G->getLine(), /*Column*/ 0, G->getFile());
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DISubprogram *SP) {
   assert(SP);
 
-  addSourceLine(Die, SP->getLine(), SP->getFile());
+  addSourceLine(Die, SP->getLine(), /*Column*/ 0, SP->getFile());
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DILabel *L) {
   assert(L);
 
-  addSourceLine(Die, L->getLine(), L->getFile());
+  addSourceLine(Die, L->getLine(), L->getColumn(), L->getFile());
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DIType *Ty) {
   assert(Ty);
 
-  addSourceLine(Die, Ty->getLine(), Ty->getFile());
+  addSourceLine(Die, Ty->getLine(), /*Column*/ 0, Ty->getFile());
 }
 
 void DwarfUnit::addSourceLine(DIE &Die, const DIObjCProperty *Ty) {
   assert(Ty);
 
-  addSourceLine(Die, Ty->getLine(), Ty->getFile());
+  addSourceLine(Die, Ty->getLine(), /*Column*/ 0, Ty->getFile());
 }
 
 void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -216,7 +216,7 @@ class DwarfUnit : public DIEUnit {
                 DIEBlock *Block);
 
   /// Add location information to specified debug information entry.
-  void addSourceLine(DIE &Die, unsigned Line, const DIFile *File);
+  void addSourceLine(DIE &Die, unsigned Line, unsigned Column, const DIFile *File);
   void addSourceLine(DIE &Die, const DILocalVariable *V);
   void addSourceLine(DIE &Die, const DIGlobalVariable *G);
   void addSourceLine(DIE &Die, const DISubprogram *SP);
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -715,6 +715,7 @@ static void printExtendedName(raw_ostream &OS, const DINode *Node,
     Res = V->getName();
     Line = V->getLine();
   } else if (const auto *L = dyn_cast<const DILabel>(Node)) {
+    // XXX what are we doing here? Adjust it?
     Res = L->getName();
     Line = L->getLine();
   }
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
@@ -2611,6 +2611,10 @@ static void writeDILabel(raw_ostream &Out, const DILabel *N,
   Printer.printString("name", N->getName());
   Printer.printMetadata("file", N->getRawFile());
   Printer.printInt("line", N->getLine());
+  Printer.printInt("column", N->getColumn());
+  Printer.printBool("isArtificial", N->isArtificial(), false);
+  if (N->getCoroSuspendIdx())
+    Printer.printInt("coroSuspendIdx", *N->getCoroSuspendIdx(), /* ShouldSkipZero */ false);
   Out << ")";
 }
 
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
@@ -946,9 +946,11 @@ DILocalVariable *DIBuilder::createParameterVariable(
 }
 
 DILabel *DIBuilder::createLabel(DIScope *Context, StringRef Name, DIFile *File,
-                                 unsigned LineNo, bool AlwaysPreserve) {
+                                 unsigned LineNo, unsigned Column, bool IsArtificial,
+                                 std::optional<unsigned> CoroSuspendIdx,
+                                 bool AlwaysPreserve) {
   auto *Scope = cast<DILocalScope>(Context);
-  auto *Node = DILabel::get(VMContext, Scope, Name, File, LineNo);
+  auto *Node = DILabel::get(VMContext, Scope, Name, File, LineNo, Column, IsArtificial, CoroSuspendIdx);
 
   if (AlwaysPreserve) {
     /// The optimizer may remove labels. If there is an interest
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
@@ -1837,7 +1837,8 @@ LLVMMetadataRef LLVMDIBuilderCreateLabel(LLVMDIBuilderRef Builder,
                                          LLVMBool AlwaysPreserve) {
   return wrap(unwrap(Builder)->createLabel(
       unwrapDI<DIScope>(Context), StringRef(Name, NameLen),
-      unwrapDI<DIFile>(File), LineNo, AlwaysPreserve));
+      unwrapDI<DIFile>(File), LineNo, /*Column*/ 0, /*IsArtificial*/ false,
+      /*CoroSuspendIdx*/ std::nullopt, AlwaysPreserve));
 }
 
 LLVMDbgRecordRef LLVMDIBuilderInsertLabelBefore(LLVMDIBuilderRef Builder,
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
diff --git a/llvm/lib/Transforms/Coroutines/CoroSplit.cpp b/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
diff --git a/llvm/unittests/IR/IRBuilderTest.cpp b/llvm/unittests/IR/IRBuilderTest.cpp

Original file line number	Diff line number	Diff line change
`@@ -12,5 +12,5 @@ int f1(int a, int b) {`
`12`	`12`	`return sum;`
`13`	`13`	`}`
`14`	`14`
`15`		`-// CHECK: [[LABEL_METADATA]] = !DILabel({{.}}, name: "top", {{.}}, line: 9)`
	`15`	`+// CHECK: [[LABEL_METADATA]] = !DILabel({{.}}, name: "top", {{.}}, line: 9, column: 1)`
`16`	`16`	`// CHECK: [[LABEL_LOCATION]] = !DILocation(line: 9,`