Update clang to trunk r290819 and resolve conflicts.

1 files changed, 316 insertions, 57 deletions

diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaCoroutine.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaCoroutine.cpp
index c8715fff4159..3109358df464 100644
--- a/contrib/llvm/tools/clang/lib/Sema/SemaCoroutine.cpp
+++ b/contrib/llvm/tools/clang/lib/Sema/SemaCoroutine.cpp
@@ -26,15 +26,15 @@ using namespace sema;
 static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
                                   SourceLocation Loc) {
   // FIXME: Cache std::coroutine_traits once we've found it.
-  NamespaceDecl *Std = S.getStdNamespace();
-  if (!Std) {
+  NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
+  if (!StdExp) {
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_not_found);
     return QualType();
   }
 
   LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_traits"),
                       Loc, Sema::LookupOrdinaryName);
-  if (!S.LookupQualifiedName(Result, Std)) {
+  if (!S.LookupQualifiedName(Result, StdExp)) {
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_not_found);
     return QualType();
   }
@@ -78,7 +78,7 @@ static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
   auto *Promise = R.getAsSingle<TypeDecl>();
   if (!Promise) {
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_promise_type_not_found)
-      << RD;
+        << RD;
     return QualType();
   }
 
@@ -86,75 +86,131 @@ static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
   QualType PromiseType = S.Context.getTypeDeclType(Promise);
   if (!PromiseType->getAsCXXRecordDecl()) {
     // Use the fully-qualified name of the type.
-    auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, Std);
+    auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
     NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
                                       CoroTrait.getTypePtr());
     PromiseType = S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
 
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_promise_type_not_class)
-      << PromiseType;
+        << PromiseType;
     return QualType();
   }
 
   return PromiseType;
 }
 
-/// Check that this is a context in which a coroutine suspension can appear.
-static FunctionScopeInfo *
-checkCoroutineContext(Sema &S, SourceLocation Loc, StringRef Keyword) {
+static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
+                                    StringRef Keyword) {
   // 'co_await' and 'co_yield' are not permitted in unevaluated operands.
   if (S.isUnevaluatedContext()) {
     S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
-    return nullptr;
+    return false;
   }
 
   // Any other usage must be within a function.
-  // FIXME: Reject a coroutine with a deduced return type.
   auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
   if (!FD) {
     S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
                     ? diag::err_coroutine_objc_method
                     : diag::err_coroutine_outside_function) << Keyword;
-  } else if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD)) {
-    // Coroutines TS [special]/6:
-    //   A special member function shall not be a coroutine.
-    //
-    // FIXME: We assume that this really means that a coroutine cannot
-    //        be a constructor or destructor.
-    S.Diag(Loc, diag::err_coroutine_ctor_dtor)
-      << isa<CXXDestructorDecl>(FD) << Keyword;
-  } else if (FD->isConstexpr()) {
-    S.Diag(Loc, diag::err_coroutine_constexpr) << Keyword;
-  } else if (FD->isVariadic()) {
-    S.Diag(Loc, diag::err_coroutine_varargs) << Keyword;
-  } else {
-    auto *ScopeInfo = S.getCurFunction();
-    assert(ScopeInfo && "missing function scope for function");
-
-    // If we don't have a promise variable, build one now.
-    if (!ScopeInfo->CoroutinePromise) {
-      QualType T =
-          FD->getType()->isDependentType()
-              ? S.Context.DependentTy
-              : lookupPromiseType(S, FD->getType()->castAs<FunctionProtoType>(),
-                                  Loc);
-      if (T.isNull())
-        return nullptr;
-
-      // Create and default-initialize the promise.
-      ScopeInfo->CoroutinePromise =
-          VarDecl::Create(S.Context, FD, FD->getLocation(), FD->getLocation(),
-                          &S.PP.getIdentifierTable().get("__promise"), T,
-                          S.Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
-      S.CheckVariableDeclarationType(ScopeInfo->CoroutinePromise);
-      if (!ScopeInfo->CoroutinePromise->isInvalidDecl())
-        S.ActOnUninitializedDecl(ScopeInfo->CoroutinePromise, false);
-    }
+    return false;
+  }
 
-    return ScopeInfo;
+  // An enumeration for mapping the diagnostic type to the correct diagnostic
+  // selection index.
+  enum InvalidFuncDiag {
+    DiagCtor = 0,
+    DiagDtor,
+    DiagCopyAssign,
+    DiagMoveAssign,
+    DiagMain,
+    DiagConstexpr,
+    DiagAutoRet,
+    DiagVarargs,
+  };
+  bool Diagnosed = false;
+  auto DiagInvalid = [&](InvalidFuncDiag ID) {
+    S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
+    Diagnosed = true;
+    return false;
+  };
+
+  // Diagnose when a constructor, destructor, copy/move assignment operator,
+  // or the function 'main' are declared as a coroutine.
+  auto *MD = dyn_cast<CXXMethodDecl>(FD);
+  if (MD && isa<CXXConstructorDecl>(MD))
+    return DiagInvalid(DiagCtor);
+  else if (MD && isa<CXXDestructorDecl>(MD))
+    return DiagInvalid(DiagDtor);
+  else if (MD && MD->isCopyAssignmentOperator())
+    return DiagInvalid(DiagCopyAssign);
+  else if (MD && MD->isMoveAssignmentOperator())
+    return DiagInvalid(DiagMoveAssign);
+  else if (FD->isMain())
+    return DiagInvalid(DiagMain);
+
+  // Emit a diagnostics for each of the following conditions which is not met.
+  if (FD->isConstexpr())
+    DiagInvalid(DiagConstexpr);
+  if (FD->getReturnType()->isUndeducedType())
+    DiagInvalid(DiagAutoRet);
+  if (FD->isVariadic())
+    DiagInvalid(DiagVarargs);
+
+  return !Diagnosed;
+}
+
+/// Check that this is a context in which a coroutine suspension can appear.
+static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
+                                                StringRef Keyword) {
+  if (!isValidCoroutineContext(S, Loc, Keyword))
+    return nullptr;
+
+  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
+  auto *FD = cast<FunctionDecl>(S.CurContext);
+  auto *ScopeInfo = S.getCurFunction();
+  assert(ScopeInfo && "missing function scope for function");
+
+  // If we don't have a promise variable, build one now.
+  if (!ScopeInfo->CoroutinePromise) {
+    QualType T = FD->getType()->isDependentType()
+                     ? S.Context.DependentTy
+                     : lookupPromiseType(
+                           S, FD->getType()->castAs<FunctionProtoType>(), Loc);
+    if (T.isNull())
+      return nullptr;
+
+    // Create and default-initialize the promise.
+    ScopeInfo->CoroutinePromise =
+        VarDecl::Create(S.Context, FD, FD->getLocation(), FD->getLocation(),
+                        &S.PP.getIdentifierTable().get("__promise"), T,
+                        S.Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
+    S.CheckVariableDeclarationType(ScopeInfo->CoroutinePromise);
+    if (!ScopeInfo->CoroutinePromise->isInvalidDecl())
+      S.ActOnUninitializedDecl(ScopeInfo->CoroutinePromise, false);
   }
 
-  return nullptr;
+  return ScopeInfo;
+}
+
+static Expr *buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id,
+                              MutableArrayRef<Expr *> CallArgs) {
+  StringRef Name = S.Context.BuiltinInfo.getName(Id);
+  LookupResult R(S, &S.Context.Idents.get(Name), Loc, Sema::LookupOrdinaryName);
+  S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
+
+  auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
+  assert(BuiltInDecl && "failed to find builtin declaration");
+
+  ExprResult DeclRef =
+      S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
+  assert(DeclRef.isUsable() && "Builtin reference cannot fail");
+
+  ExprResult Call =
+      S.ActOnCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
+
+  assert(!Call.isInvalid() && "Call to builtin cannot fail!");
+  return Call.get();
 }
 
 /// Build a call to 'operator co_await' if there is a suitable operator for
@@ -199,7 +255,7 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, SourceLocation Loc,
   const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
   for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
     Expr *Operand = new (S.Context) OpaqueValueExpr(
-        Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
+      Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
 
     // FIXME: Pass coroutine handle to await_suspend.
     ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], None);
@@ -213,6 +269,11 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, SourceLocation Loc,
 }
 
 ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
+  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await");
+  if (!Coroutine) {
+    CorrectDelayedTyposInExpr(E);
+    return ExprError();
+  }
   if (E->getType()->isPlaceholderType()) {
     ExprResult R = CheckPlaceholderExpr(E);
     if (R.isInvalid()) return ExprError();
@@ -222,6 +283,7 @@ ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
   ExprResult Awaitable = buildOperatorCoawaitCall(*this, S, Loc, E);
   if (Awaitable.isInvalid())
     return ExprError();
+
   return BuildCoawaitExpr(Loc, Awaitable.get());
 }
 ExprResult Sema::BuildCoawaitExpr(SourceLocation Loc, Expr *E) {
@@ -275,8 +337,10 @@ static ExprResult buildPromiseCall(Sema &S, FunctionScopeInfo *Coroutine,
 
 ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
   auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
-  if (!Coroutine)
+  if (!Coroutine) {
+    CorrectDelayedTyposInExpr(E);
     return ExprError();
+  }
 
   // Build yield_value call.
   ExprResult Awaitable =
@@ -325,8 +389,14 @@ ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
 }
 
 StmtResult Sema::ActOnCoreturnStmt(SourceLocation Loc, Expr *E) {
+  auto *Coroutine = checkCoroutineContext(*this, Loc, "co_return");
+  if (!Coroutine) {
+    CorrectDelayedTyposInExpr(E);
+    return StmtError();
+  }
   return BuildCoreturnStmt(Loc, E);
 }
+
 StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E) {
   auto *Coroutine = checkCoroutineContext(*this, Loc, "co_return");
   if (!Coroutine)
@@ -343,7 +413,7 @@ StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E) {
   // of scope, we should treat the operand as an xvalue for this overload
   // resolution.
   ExprResult PC;
-  if (E && !E->getType()->isVoidType()) {
+  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
     PC = buildPromiseCall(*this, Coroutine, Loc, "return_value", E);
   } else {
     E = MakeFullDiscardedValueExpr(E).get();
@@ -359,6 +429,141 @@ StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E) {
   return Res;
 }
 
+static ExprResult buildStdCurrentExceptionCall(Sema &S, SourceLocation Loc) {
+  NamespaceDecl *Std = S.getStdNamespace();
+  if (!Std) {
+    S.Diag(Loc, diag::err_implied_std_current_exception_not_found);
+    return ExprError();
+  }
+  LookupResult Result(S, &S.PP.getIdentifierTable().get("current_exception"),
+                      Loc, Sema::LookupOrdinaryName);
+  if (!S.LookupQualifiedName(Result, Std)) {
+    S.Diag(Loc, diag::err_implied_std_current_exception_not_found);
+    return ExprError();
+  }
+
+  // FIXME The STL is free to provide more than one overload.
+  FunctionDecl *FD = Result.getAsSingle<FunctionDecl>();
+  if (!FD) {
+    S.Diag(Loc, diag::err_malformed_std_current_exception);
+    return ExprError();
+  }
+  ExprResult Res = S.BuildDeclRefExpr(FD, FD->getType(), VK_LValue, Loc);
+  Res = S.ActOnCallExpr(/*Scope*/ nullptr, Res.get(), Loc, None, Loc);
+  if (Res.isInvalid()) {
+    S.Diag(Loc, diag::err_malformed_std_current_exception);
+    return ExprError();
+  }
+  return Res;
+}
+
+// Find an appropriate delete for the promise.
+static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
+                                          QualType PromiseType) {
+  FunctionDecl *OperatorDelete = nullptr;
+
+  DeclarationName DeleteName =
+      S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);
+
+  auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
+  assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
+
+  if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
+    return nullptr;
+
+  if (!OperatorDelete) {
+    // Look for a global declaration.
+    const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
+    const bool Overaligned = false;
+    OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
+                                                     Overaligned, DeleteName);
+  }
+  S.MarkFunctionReferenced(Loc, OperatorDelete);
+  return OperatorDelete;
+}
+
+// Builds allocation and deallocation for the coroutine. Returns false on
+// failure.
+static bool buildAllocationAndDeallocation(Sema &S, SourceLocation Loc,
+                                           FunctionScopeInfo *Fn,
+                                           Expr *&Allocation,
+                                           Stmt *&Deallocation) {
+  TypeSourceInfo *TInfo = Fn->CoroutinePromise->getTypeSourceInfo();
+  QualType PromiseType = TInfo->getType();
+  if (PromiseType->isDependentType())
+    return true;
+
+  if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
+    return false;
+
+  // FIXME: Add support for get_return_object_on_allocation failure.
+  // FIXME: Add support for stateful allocators.
+
+  FunctionDecl *OperatorNew = nullptr;
+  FunctionDecl *OperatorDelete = nullptr;
+  FunctionDecl *UnusedResult = nullptr;
+  bool PassAlignment = false;
+
+  S.FindAllocationFunctions(Loc, SourceRange(),
+                            /*UseGlobal*/ false, PromiseType,
+                            /*isArray*/ false, PassAlignment,
+                            /*PlacementArgs*/ None, OperatorNew, UnusedResult);
+
+  OperatorDelete = findDeleteForPromise(S, Loc, PromiseType);
+
+  if (!OperatorDelete || !OperatorNew)
+    return false;
+
+  Expr *FramePtr =
+      buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
+
+  Expr *FrameSize =
+      buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
+
+  // Make new call.
+
+  ExprResult NewRef =
+      S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
+  if (NewRef.isInvalid())
+    return false;
+
+  ExprResult NewExpr =
+      S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, FrameSize, Loc);
+  if (NewExpr.isInvalid())
+    return false;
+
+  Allocation = NewExpr.get();
+
+  // Make delete call.
+
+  QualType OpDeleteQualType = OperatorDelete->getType();
+
+  ExprResult DeleteRef =
+      S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
+  if (DeleteRef.isInvalid())
+    return false;
+
+  Expr *CoroFree =
+      buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
+
+  SmallVector<Expr *, 2> DeleteArgs{CoroFree};
+
+  // Check if we need to pass the size.
+  const auto *OpDeleteType =
+      OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
+  if (OpDeleteType->getNumParams() > 1)
+    DeleteArgs.push_back(FrameSize);
+
+  ExprResult DeleteExpr =
+      S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
+  if (DeleteExpr.isInvalid())
+    return false;
+
+  Deallocation = DeleteExpr.get();
+
+  return true;
+}
+
 void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
   FunctionScopeInfo *Fn = getCurFunction();
   assert(Fn && !Fn->CoroutineStmts.empty() && "not a coroutine");
@@ -369,8 +574,8 @@ void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
     Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
     auto *First = Fn->CoroutineStmts[0];
     Diag(First->getLocStart(), diag::note_declared_coroutine_here)
-      << (isa<CoawaitExpr>(First) ? 0 :
-          isa<CoyieldExpr>(First) ? 1 : 2);
+        << (isa<CoawaitExpr>(First) ? 0 :
+            isa<CoyieldExpr>(First) ? 1 : 2);
   }
 
   bool AnyCoawaits = false;
@@ -413,15 +618,69 @@ void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
   if (FinalSuspend.isInvalid())
     return FD->setInvalidDecl();
 
-  // FIXME: Perform analysis of set_exception call.
+  // Form and check allocation and deallocation calls.
+  Expr *Allocation = nullptr;
+  Stmt *Deallocation = nullptr;
+  if (!buildAllocationAndDeallocation(*this, Loc, Fn, Allocation, Deallocation))
+    return FD->setInvalidDecl();
 
-  // FIXME: Try to form 'p.return_void();' expression statement to handle
   // control flowing off the end of the coroutine.
+  // Also try to form 'p.set_exception(std::current_exception());' to handle
+  // uncaught exceptions.
+  ExprResult SetException;
+  StmtResult Fallthrough;
+  if (Fn->CoroutinePromise &&
+      !Fn->CoroutinePromise->getType()->isDependentType()) {
+    CXXRecordDecl *RD = Fn->CoroutinePromise->getType()->getAsCXXRecordDecl();
+    assert(RD && "Type should have already been checked");
+    // [dcl.fct.def.coroutine]/4
+    // The unqualified-ids 'return_void' and 'return_value' are looked up in
+    // the scope of class P. If both are found, the program is ill-formed.
+    DeclarationName RVoidDN = PP.getIdentifierInfo("return_void");
+    LookupResult RVoidResult(*this, RVoidDN, Loc, Sema::LookupMemberName);
+    const bool HasRVoid = LookupQualifiedName(RVoidResult, RD);
+
+    DeclarationName RValueDN = PP.getIdentifierInfo("return_value");
+    LookupResult RValueResult(*this, RValueDN, Loc, Sema::LookupMemberName);
+    const bool HasRValue = LookupQualifiedName(RValueResult, RD);
+
+    if (HasRVoid && HasRValue) {
+      // FIXME Improve this diagnostic
+      Diag(FD->getLocation(), diag::err_coroutine_promise_return_ill_formed)
+          << RD;
+      return FD->setInvalidDecl();
+    } else if (HasRVoid) {
+      // If the unqualified-id return_void is found, flowing off the end of a
+      // coroutine is equivalent to a co_return with no operand. Otherwise,
+      // flowing off the end of a coroutine results in undefined behavior.
+      Fallthrough = BuildCoreturnStmt(FD->getLocation(), nullptr);
+      Fallthrough = ActOnFinishFullStmt(Fallthrough.get());
+      if (Fallthrough.isInvalid())
+        return FD->setInvalidDecl();
+    }
+
+    // [dcl.fct.def.coroutine]/3
+    // The unqualified-id set_exception is found in the scope of P by class
+    // member access lookup (3.4.5).
+    DeclarationName SetExDN = PP.getIdentifierInfo("set_exception");
+    LookupResult SetExResult(*this, SetExDN, Loc, Sema::LookupMemberName);
+    if (LookupQualifiedName(SetExResult, RD)) {
+      // Form the call 'p.set_exception(std::current_exception())'
+      SetException = buildStdCurrentExceptionCall(*this, Loc);
+      if (SetException.isInvalid())
+        return FD->setInvalidDecl();
+      Expr *E = SetException.get();
+      SetException = buildPromiseCall(*this, Fn, Loc, "set_exception", E);
+      SetException = ActOnFinishFullExpr(SetException.get(), Loc);
+      if (SetException.isInvalid())
+        return FD->setInvalidDecl();
+    }
+  }
 
   // Build implicit 'p.get_return_object()' expression and form initialization
   // of return type from it.
   ExprResult ReturnObject =
-    buildPromiseCall(*this, Fn, Loc, "get_return_object", None);
+      buildPromiseCall(*this, Fn, Loc, "get_return_object", None);
   if (ReturnObject.isInvalid())
     return FD->setInvalidDecl();
   QualType RetType = FD->getReturnType();
@@ -443,6 +702,6 @@ void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
   // Build body for the coroutine wrapper statement.
   Body = new (Context) CoroutineBodyStmt(
       Body, PromiseStmt.get(), InitialSuspend.get(), FinalSuspend.get(),
-      /*SetException*/nullptr, /*Fallthrough*/nullptr,
+      SetException.get(), Fallthrough.get(), Allocation, Deallocation,
       ReturnObject.get(), ParamMoves);
 }