[Coroutine][DebugInfo] Update the linkage name of the declaration of coro-split functions in the debug info.

[DianQK]

Summary

This patch adds the linkage name update to DISubprogram's declaration after 6ce76ff7eb7640e53b65f0473848ce7d08165c98.

Background: After D152095, I added https://github.com/apple/swift/pull/67077 to split the DISubprogram into definition and declaration. A failed test case appears TestSwiftTaskSwitch.py#L18.

[DianQK]

Thanks for your review.

llvm/include/llvm/IR/DebugInfoMetadata.h

public:
   }
   void replaceUnit(DICompileUnit *CU) { replaceOperandWith(5, CU); }
   DITemplateParameterArray getTemplateParams() const {
     return cast_or_null<MDTuple>(getRawTemplateParams());
   }
   DISubprogram *getDeclaration() const {
     return cast_or_null<DISubprogram>(getRawDeclaration());
   }
+  void replaceDeclaration(DISubprogram *Decl) { replaceOperandWith(6, Decl); }
   DINodeArray getRetainedNodes() const {
     return cast_or_null<MDTuple>(getRawRetainedNodes());
   }
   DITypeArray getThrownTypes() const {
     return cast_or_null<MDTuple>(getRawThrownTypes());
   }
   DINodeArray getAnnotations() const {
     return cast_or_null<MDTuple>(getRawAnnotations());

llvm/lib/Transforms/Coroutines/CoroSplit.cpp

if (DISubprogram *SP = NewF->getSubprogram()) {
     // Update the linkage name to reflect the modified symbol name. It
     // is necessary to update the linkage name in Swift, since the
     // mangling changes for resume functions. It might also be the
     // right thing to do in C++, but due to a limitation in LLVM's
     // AsmPrinter we can only do this if the function doesn't have an
     // abstract specification, since the DWARF backend expects the
     // abstract specification to contain the linkage name and asserts
     // that they are identical.
-    if (!SP->getDeclaration() && SP->getUnit() &&
-        SP->getUnit()->getSourceLanguage() == dwarf::DW_LANG_Swift)
+    if (SP->getUnit() &&
+        SP->getUnit()->getSourceLanguage() == dwarf::DW_LANG_Swift) {
       SP->replaceLinkageName(MDString::get(Context, NewF->getName()));
+      if (auto *Decl = SP->getDeclaration()) {
+        auto *NewDecl = DISubprogram::get(
+            Decl->getContext(), Decl->getScope(), Decl->getName(),
+            NewF->getName(), Decl->getFile(), Decl->getLine(), Decl->getType(),
+            Decl->getScopeLine(), Decl->getContainingType(),
+            Decl->getVirtualIndex(), Decl->getThisAdjustment(),
+            Decl->getFlags(), Decl->getSPFlags(), Decl->getUnit(),
+            Decl->getTemplateParams(), nullptr, Decl->getRetainedNodes(),
+            Decl->getThrownTypes(), Decl->getAnnotations(),
+            Decl->getTargetFuncName());
+        SP->replaceDeclaration(NewDecl);
+      }
+    }
   }
 
   NewF->setLinkage(savedLinkage);
   NewF->setVisibility(savedVisibility);
   NewF->setUnnamedAddr(savedUnnamedAddr);
   NewF->setDLLStorageClass(savedDLLStorageClass);
   // The function sanitizer metadata needs to match the signature of the
   // function it is being attached to. However this does not hold for split

llvm/test/Transforms/Coroutines/coro-async-declaration.ll

 !38 = distinct !DISubprogram(name: "main", linkageName: "$s4main5entryOAAyyYaFZ", scope: !39, file: !1, line: 2, type: !40, scopeLine: 2, spFlags: DISPFlagDefinition, unit: !0, declaration: !45, retainedNodes: !46)
 !39 = !DICompositeType(tag: DW_TAG_structure_type, name: "$s4main5entryOD", scope: !4, flags: DIFlagFwdDecl, runtimeLang: DW_LANG_Swift)
 !40 = !DISubroutineType(types: !41)
 !41 = !{!42, !43}
 !42 = !DICompositeType(tag: DW_TAG_structure_type, name: "$sytD", flags: DIFlagFwdDecl, runtimeLang: DW_LANG_Swift)
 !43 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "$s4main5entryOXMtD", file: !44, size: 8, flags: DIFlagArtificial, runtimeLang: DW_LANG_Swift, identifier: "$s4main5entryOXMtD")
 !44 = !DIFile(filename: "<compiler-generated>", directory: "")
 ; CHECK-DAG: ![[DECL:[0-9]+]] = !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZ"
+; CHECK-DAG: ![[DECL_Q0:[0-9]+]] = !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZTQ0_"
+; CHECK-DAG: ![[DECL_Y1:[0-9]+]] = !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZTY1_"
 ; CHECK-DAG: distinct !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZ"{{.*}}, declaration: ![[DECL]]
-; CHECK-DAG: distinct !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZ"{{.*}}, declaration: ![[DECL]]
-; CHECK-DAG: distinct !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZ"{{.*}}, declaration: ![[DECL]]
+; CHECK-DAG: distinct !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZTQ0_"{{.*}}, declaration: ![[DECL_Q0]]
+; CHECK-DAG: distinct !DISubprogram({{.*}}, linkageName: "$s4main5entryOAAyyYaFZTY1_"{{.*}}, declaration: ![[DECL_Y1]]
 !45 = !DISubprogram(name: "main", linkageName: "$s4main5entryOAAyyYaFZ", scope: !39, file: !1, line: 2, type: !40, scopeLine: 2, spFlags: 0)
 !46 = !{!47, !49}
 !47 = !DILocalVariable(name: "self", arg: 1, scope: !38, file: !1, line: 2, type: !48, flags: DIFlagArtificial)
 !48 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !43)
 !49 = !DILocalVariable(name: "x", scope: !50, file: !1, line: 3, type: !51)
 !50 = distinct !DILexicalBlock(scope: !38, file: !1, line: 3, column: 9)
 !51 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !52)
 !52 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Int", scope: !6, file: !53, size: 64, elements: !54, runtimeLang: DW_LANG_Swift, identifier: "$sSiD")
 !53 = !DIFile(filename: "build/buildbot_incremental/swift-macosx-x86_64/lib/swift/macosx/Swift.swiftmodule/x86_64-apple-macos.swiftmodule", directory: "/Users/dianqk/swift-project")
 !54 = !{}