Merge pull request #41654 from aschwaighofer/debug_info_linkage_name_async_suspend_dispatch

IRGen: Emit the proper linkageName debug info of the containing function for async suspend dispatch thunks

Author: aschwaighofer

lib/IRGen/GenFunc.cpp

@@ -2375,7 +2375,7 @@ IRGenFunction::createAsyncDispatchFn(const FunctionPointer &fnPtr,
   IRGenFunction dispatchIGF(IGM, dispatch);
   // Don't emit debug info if we are generating a function for the prologue.
   if (IGM.DebugInfo && Builder.getCurrentDebugLocation())
-    IGM.DebugInfo->emitArtificialFunction(dispatchIGF, dispatch);
+    IGM.DebugInfo->emitOutlinedFunction(dispatchIGF, dispatch, CurFn->getName());
   auto &Builder = dispatchIGF.Builder;
   auto it = dispatchIGF.CurFn->arg_begin(), end = dispatchIGF.CurFn->arg_end();
   llvm::Value *fnPtrArg = &*(it++);

lib/IRGen/IRGenDebugInfo.cpp

@@ -204,10 +204,14 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
   void emitImport(ImportDecl *D);
   llvm::DISubprogram *emitFunction(const SILDebugScope *DS, llvm::Function *Fn,
                                    SILFunctionTypeRepresentation Rep,
-                                   SILType Ty, DeclContext *DeclCtx = nullptr);
+                                   SILType Ty, DeclContext *DeclCtx = nullptr,
+                                   StringRef oulinedFromName = StringRef());
   llvm::DISubprogram *emitFunction(SILFunction &SILFn, llvm::Function *Fn);
   void emitArtificialFunction(IRBuilder &Builder, llvm::Function *Fn,
                               SILType SILTy);
+  void emitOutlinedFunction(IRBuilder &Builder,
+                            llvm::Function *Fn,
+                            StringRef outlinedFromName);
 
   /// Return false if we fail to create the right DW_OP_LLVM_fragment operand.
   bool handleFragmentDIExpr(const SILDIExprOperand &CurDIExprOp,
@@ -2261,7 +2265,8 @@ llvm::DISubprogram *IRGenDebugInfoImpl::emitFunction(SILFunction &SILFn,
 llvm::DISubprogram *
 IRGenDebugInfoImpl::emitFunction(const SILDebugScope *DS, llvm::Function *Fn,
                                  SILFunctionTypeRepresentation Rep,
-                                 SILType SILTy, DeclContext *DeclCtx) {
+                                 SILType SILTy, DeclContext *DeclCtx,
+                                 StringRef outlinedFromName) {
   auto Cached = ScopeCache.find(DS);
   if (Cached != ScopeCache.end()) {
     auto SP = cast<llvm::DISubprogram>(Cached->second);
@@ -2277,7 +2282,9 @@ IRGenDebugInfoImpl::emitFunction(const SILDebugScope *DS, llvm::Function *Fn,
   auto *SILFn = DS ? DS->Parent.dyn_cast<SILFunction *>() : nullptr;
 
   StringRef LinkageName;
-  if (Fn)
+  if (!outlinedFromName.empty())
+    LinkageName = outlinedFromName;
+  else if (Fn)
     LinkageName = Fn->getName();
   else if (DS)
     LinkageName = SILFn->getName();
@@ -2407,6 +2414,18 @@ void IRGenDebugInfoImpl::emitArtificialFunction(IRBuilder &Builder,
   setCurrentLoc(Builder, Scope, ALoc);
 }
 
+void IRGenDebugInfoImpl::emitOutlinedFunction(IRBuilder &Builder,
+                                              llvm::Function *Fn,
+                                              StringRef outlinedFromName) {
+  RegularLocation ALoc = RegularLocation::getAutoGeneratedLocation();
+  const SILDebugScope *Scope = new (IGM.getSILModule()) SILDebugScope(ALoc);
+  emitFunction(Scope, Fn, SILFunctionTypeRepresentation::Thin, SILType(),
+               nullptr, outlinedFromName);
+  /// Reusing the current file would be wrong: An objc thunk, for example, could
+  /// be triggered from any random location. Use a placeholder name instead.
+  setCurrentLoc(Builder, Scope, ALoc);
+}
+
 bool IRGenDebugInfoImpl::handleFragmentDIExpr(
     const SILDIExprOperand &CurDIExprOp, SmallVectorImpl<uint64_t> &Operands) {
   assert(CurDIExprOp.getOperator() == SILDIExprOperator::Fragment);
@@ -2911,7 +2930,11 @@ void IRGenDebugInfo::emitArtificialFunction(IRBuilder &Builder,
   static_cast<IRGenDebugInfoImpl *>(this)->emitArtificialFunction(Builder, Fn,
                                                                   SILTy);
 }
-
+void IRGenDebugInfo::emitOutlinedFunction(IRBuilder &Builder,
+                                          llvm::Function *Fn, StringRef name) {
+  static_cast<IRGenDebugInfoImpl *>(this)->emitOutlinedFunction(Builder, Fn,
+                                                                name);
+}
 void IRGenDebugInfo::emitVariableDeclaration(
     IRBuilder &Builder, ArrayRef<llvm::Value *> Storage, DebugTypeInfo Ty,
     const SILDebugScope *DS, Optional<SILLocation> VarLoc,

lib/IRGen/IRGenDebugInfo.h

@@ -145,6 +145,16 @@ class IRGenDebugInfo {
   void emitArtificialFunction(IRBuilder &Builder,
                               llvm::Function *Fn, SILType SILTy = SILType());
 
+  inline void emitOutlinedFunction(IRGenFunction &IGF,
+                                   llvm::Function *Fn,
+                                   StringRef outlinedFromName) {
+    emitOutlinedFunction(IGF.Builder, Fn, outlinedFromName);
+  }
+
+  void emitOutlinedFunction(IRBuilder &Builder,
+                            llvm::Function *Fn,
+                            StringRef outlinedFromName);
+
   /// Emit a dbg.declare intrinsic at the current insertion point and
   /// the Builder's current debug location.
   void emitVariableDeclaration(IRBuilder &Builder,

test/IRGen/async/get_async_continuation.sil

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend  -enable-objc-interop  -primary-file %s -emit-ir -sil-verify-all -disable-llvm-optzns -disable-swift-specific-llvm-optzns | %IRGenFileCheck %s
+// RUN: %target-swift-frontend -g -enable-objc-interop  -primary-file %s -emit-ir -sil-verify-all -disable-llvm-optzns -disable-swift-specific-llvm-optzns | %IRGenFileCheck %s
 // RUN: %target-swift-frontend  -enable-objc-interop  -primary-file %s -emit-ir -sil-verify-all
 
 // REQUIRES: concurrency
@@ -72,10 +72,11 @@ bb0:
 // CHECK:      {{musttail call swifttailcc|tail call swiftcc}} void @swift_continuation_await(%swift.continuation_context* %0)
 // CHECK-NEXT: ret void
 
-// CHECK: define {{.*}} void @async_continuation.0(i8* %0, %swift.context* %1)
+// CHECK: define {{.*}} void @async_continuation.0(i8* %0, %swift.context* %1){{.*}}!dbg ![[DBG:[0-9]+]]
 // CHECK-NOT: define
 // CHECK:  tail call swift{{(tail)?}}cc void %{{.*}}(%swift.context* swiftasync %1)
 // CHECK-NEXT:  ret void
+// CHECK: ![[DBG]] = distinct !DISubprogram(linkageName: "async_continuation"
 
 sil @async_continuation : $@async () -> () {
 entry: