[clang][DebugInfo] Emit DW_AT_language_{name, version} for DWARFv6

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -647,6 +647,68 @@ StringRef CGDebugInfo::getCurrentDirname() {
   return CGM.getCodeGenOpts().DebugCompilationDir;
 }
 
+static llvm::dwarf::SourceLanguage GetSourceLanguage(const CodeGenModule &CGM) {
+  const CodeGenOptions &CGO = CGM.getCodeGenOpts();
+  const LangOptions &LO = CGM.getLangOpts();
+
+  assert(CGO.DwarfVersion <= 5);
+
+  llvm::dwarf::SourceLanguage LangTag;
+  if (LO.CPlusPlus) {
+    if (LO.ObjC)
+      LangTag = llvm::dwarf::DW_LANG_ObjC_plus_plus;
+    else if (CGO.DebugStrictDwarf && CGO.DwarfVersion < 5)
+      LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
+    else if (LO.CPlusPlus14)
+      LangTag = llvm::dwarf::DW_LANG_C_plus_plus_14;
+    else if (LO.CPlusPlus11)
+      LangTag = llvm::dwarf::DW_LANG_C_plus_plus_11;
+    else
+      LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
+  } else if (LO.ObjC) {
+    LangTag = llvm::dwarf::DW_LANG_ObjC;
+  } else if (LO.OpenCL && (!CGO.DebugStrictDwarf || CGO.DwarfVersion >= 5)) {
+    LangTag = llvm::dwarf::DW_LANG_OpenCL;
+  } else if (LO.C11 && !(CGO.DebugStrictDwarf && CGO.DwarfVersion < 5)) {
+    LangTag = llvm::dwarf::DW_LANG_C11;
+  } else if (LO.C99) {
+    LangTag = llvm::dwarf::DW_LANG_C99;
+  } else {
+    LangTag = llvm::dwarf::DW_LANG_C89;
+  }
+
+  return LangTag;
+}
+
+static llvm::DISourceLanguageName
+GetDISourceLanguageName(const CodeGenModule &CGM) {
+  // Emit pre-DWARFv6 language codes.
+  if (CGM.getCodeGenOpts().DwarfVersion < 6)
+    return llvm::DISourceLanguageName(GetSourceLanguage(CGM));
+
+  const LangOptions &LO = CGM.getLangOpts();
+
+  uint32_t LangVersion = 0;
+  llvm::dwarf::SourceLanguageName LangTag;
+  if (LO.CPlusPlus) {
+    if (LO.ObjC) {
+      LangTag = llvm::dwarf::DW_LNAME_ObjC_plus_plus;
+    } else {
+      LangTag = llvm::dwarf::DW_LNAME_C_plus_plus;
+      LangVersion = LO.getCPlusPlusLangStd().value_or(0);
+    }
+  } else if (LO.ObjC) {
+    LangTag = llvm::dwarf::DW_LNAME_ObjC;
+  } else if (LO.OpenCL) {
+    LangTag = llvm::dwarf::DW_LNAME_OpenCL_C;
+  } else {
+    LangTag = llvm::dwarf::DW_LNAME_C;
+    LangVersion = LO.getCLangStd().value_or(0);
+  }
+
+  return llvm::DISourceLanguageName(LangTag, LangVersion);
+}
+
 void CGDebugInfo::CreateCompileUnit() {
   SmallString<64> Checksum;
   std::optional<llvm::DIFile::ChecksumKind> CSKind;
@@ -702,31 +764,6 @@ void CGDebugInfo::CreateCompileUnit() {
     }
   }
 
-  llvm::dwarf::SourceLanguage LangTag;
-  if (LO.CPlusPlus) {
-    if (LO.ObjC)
-      LangTag = llvm::dwarf::DW_LANG_ObjC_plus_plus;
-    else if (CGO.DebugStrictDwarf && CGO.DwarfVersion < 5)
-      LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
-    else if (LO.CPlusPlus14)
-      LangTag = llvm::dwarf::DW_LANG_C_plus_plus_14;
-    else if (LO.CPlusPlus11)
-      LangTag = llvm::dwarf::DW_LANG_C_plus_plus_11;
-    else
-      LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
-  } else if (LO.ObjC) {
-    LangTag = llvm::dwarf::DW_LANG_ObjC;
-  } else if (LO.OpenCL && (!CGM.getCodeGenOpts().DebugStrictDwarf ||
-                           CGM.getCodeGenOpts().DwarfVersion >= 5)) {
-    LangTag = llvm::dwarf::DW_LANG_OpenCL;
-  } else if (LO.C11 && !(CGO.DebugStrictDwarf && CGO.DwarfVersion < 5)) {
-      LangTag = llvm::dwarf::DW_LANG_C11;
-  } else if (LO.C99) {
-    LangTag = llvm::dwarf::DW_LANG_C99;
-  } else {
-    LangTag = llvm::dwarf::DW_LANG_C89;
-  }
-
   std::string Producer = getClangFullVersion();
 
   // Figure out which version of the ObjC runtime we have.
@@ -787,7 +824,7 @@ void CGDebugInfo::CreateCompileUnit() {
 
   // Create new compile unit.
   TheCU = DBuilder.createCompileUnit(
-      llvm::DISourceLanguageName(LangTag), CUFile,
+      GetDISourceLanguageName(CGM), CUFile,
       CGOpts.EmitVersionIdentMetadata ? Producer : "",
       CGOpts.OptimizationLevel != 0 || CGOpts.PrepareForLTO ||
           CGOpts.PrepareForThinLTO,
@@ -1234,20 +1271,46 @@ llvm::DIType *CGDebugInfo::CreateType(const PointerType *Ty,
                                Ty->getPointeeType(), Unit);
 }
 
-/// \return whether a C++ mangling exists for the type defined by TD.
-static bool hasCXXMangling(const TagDecl *TD, llvm::DICompileUnit *TheCU) {
-  switch (TheCU->getSourceLanguage().getUnversionedName()) {
+static bool hasCXXMangling(llvm::dwarf::SourceLanguage Lang, bool IsTagDecl) {
+  switch (Lang) {
   case llvm::dwarf::DW_LANG_C_plus_plus:
   case llvm::dwarf::DW_LANG_C_plus_plus_11:
   case llvm::dwarf::DW_LANG_C_plus_plus_14:
     return true;
   case llvm::dwarf::DW_LANG_ObjC_plus_plus:
-    return isa<CXXRecordDecl>(TD) || isa<EnumDecl>(TD);
+    return IsTagDecl;
+  default:
+    return false;
+  }
+}
+
+static bool hasCXXMangling(llvm::dwarf::SourceLanguageName Lang,
+                           bool IsTagDecl) {
+  switch (Lang) {
+  case llvm::dwarf::DW_LNAME_C_plus_plus:
+    return true;
+  case llvm::dwarf::DW_LNAME_ObjC_plus_plus:
+    return IsTagDecl;
   default:
     return false;
   }
 }
 
+/// \return whether a C++ mangling exists for the type defined by TD.
+static bool hasCXXMangling(const TagDecl *TD, llvm::DICompileUnit *TheCU) {
+  const bool IsTagDecl = isa<CXXRecordDecl>(TD) || isa<EnumDecl>(TD);
+
+  if (llvm::DISourceLanguageName SourceLang = TheCU->getSourceLanguage();
+      SourceLang.hasVersionedName())
+    return hasCXXMangling(
+        static_cast<llvm::dwarf::SourceLanguageName>(SourceLang.getName()),
+        IsTagDecl);
+  else
+    return hasCXXMangling(
+        static_cast<llvm::dwarf::SourceLanguage>(SourceLang.getName()),
+        IsTagDecl);
+}
+
 // Determines if the debug info for this tag declaration needs a type
 // identifier. The purpose of the unique identifier is to deduplicate type
 // information for identical types across TUs. Because of the C++ one definition

clang/test/DebugInfo/CXX/versioned-language.cpp

@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=5 -std=c++98 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageName" --implicit-check-not "sourceLanguageVersion"
+//
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++98 | FileCheck %s --check-prefix=CHECK-CPP98
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++03 | FileCheck %s --check-prefix=CHECK-CPP03
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++11 | FileCheck %s --check-prefix=CHECK-CPP11
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++14 | FileCheck %s --check-prefix=CHECK-CPP14
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++17 | FileCheck %s --check-prefix=CHECK-CPP17
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++20 | FileCheck %s --check-prefix=CHECK-CPP20
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++23 | FileCheck %s --check-prefix=CHECK-CPP23
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c++2c | FileCheck %s --check-prefix=CHECK-CPP2C
+
+struct Foo {} globalVar;
+
+// CHECK-CPP98:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 199711
+// FIXME: C++03 technically has no official standard version code. From Clang's point of view C++03 and C++98 are interchangable.
+// CHECK-CPP03:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 199711
+// CHECK-CPP11:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 201103
+// CHECK-CPP14:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 201402
+// CHECK-CPP17:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 201703
+// CHECK-CPP20:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 202002
+// CHECK-CPP23:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 202302
+// CHECK-CPP2C:     !DICompileUnit(sourceLanguageName: DW_LNAME_C_plus_plus, sourceLanguageVersion: 202400

clang/test/DebugInfo/Generic/versioned-language.c

@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=5 -std=c99 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageName" --implicit-check-not "sourceLanguageVersion"
+//
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c89 | FileCheck %s --check-prefix=CHECK-C89 --implicit-check-not "sourceLanguageVersion"
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c99 | FileCheck %s --check-prefix=CHECK-C99
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c17 | FileCheck %s --check-prefix=CHECK-C17
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c23 | FileCheck %s --check-prefix=CHECK-C23
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 -std=c2y | FileCheck %s --check-prefix=CHECK-C2Y
+
+int globalVar = 10;
+
+// CHECK-C89: !DICompileUnit(sourceLanguageName: DW_LNAME_C,
+// CHECK-C99: !DICompileUnit(sourceLanguageName: DW_LNAME_C, sourceLanguageVersion: 199901
+// CHECK-C11: !DICompileUnit(sourceLanguageName: DW_LNAME_C, sourceLanguageVersion: 201112
+// CHECK-C17: !DICompileUnit(sourceLanguageName: DW_LNAME_C, sourceLanguageVersion: 201710
+// CHECK-C23: !DICompileUnit(sourceLanguageName: DW_LNAME_C, sourceLanguageVersion: 202311
+// CHECK-C2Y: !DICompileUnit(sourceLanguageName: DW_LNAME_C, sourceLanguageVersion: 202400

clang/test/DebugInfo/ObjC/versioned-language.m

@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=5 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageName" --implicit-check-not "sourceLanguageVersion"
+//
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageVersion" --check-prefix=CHECK-OBJC
+
+int globalVar = 10;
+
+// CHECK-OBJC: !DICompileUnit(sourceLanguageName: DW_LNAME_ObjC,

clang/test/DebugInfo/ObjCXX/versioned-language.mm

@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=5 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageName" --implicit-check-not "sourceLanguageVersion"
+//
+// RUN: %clang_cc1 -emit-llvm %s -o - -debug-info-kind=limited -dwarf-version=6 \
+// RUN:    | FileCheck %s --implicit-check-not "sourceLanguageVersion" --check-prefix=CHECK-OBJCXX
+
+int globalVar = 10;
+
+// CHECK-OBJCXX: !DICompileUnit(sourceLanguageName: DW_LNAME_ObjC_plus_plus,