[coroutines] Fix building of new/delete expressions when get_return_object_on_allocation_failure() is present.
Summary:
This patch implements [dcl.fct.def.coroutine]p8:
> The unqualified-id get_return_object_on_allocation_failure is looked up in the scope of
> class P by class member access lookup (3.4.5). If a declaration is found, ..., and if a
> global allocation function is selected, the ::operator new(size_t, nothrow_t) form shall be used.
> [...]
> The allocation function used in this case must have a non-throwing noexcept-specification.
Reviewers: GorNishanov, rsmith, majnemer, aaron.ballman
Reviewed By: GorNishanov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31562
llvm-svn: 300524
diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index 4a55e51..f891365 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -454,7 +454,7 @@
/*IsImplicit*/ true);
Suspend = S.ActOnFinishFullExpr(Suspend.get());
if (Suspend.isInvalid()) {
- S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
+ S.Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
<< ((Name == "initial_suspend") ? 0 : 1);
S.Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
return StmtError();
@@ -660,6 +660,39 @@
return Res;
}
+/// Look up the std::nothrow object.
+static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
+ NamespaceDecl *Std = S.getStdNamespace();
+ assert(Std && "Should already be diagnosed");
+
+ LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
+ Sema::LookupOrdinaryName);
+ if (!S.LookupQualifiedName(Result, Std)) {
+ // FIXME: <experimental/coroutine> should have been included already.
+ // If we require it to include <new> then this diagnostic is no longer
+ // needed.
+ S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
+ return nullptr;
+ }
+
+ // FIXME: Mark the variable as ODR used. This currently does not work
+ // likely due to the scope at in which this function is called.
+ auto *VD = Result.getAsSingle<VarDecl>();
+ if (!VD) {
+ Result.suppressDiagnostics();
+ // We found something weird. Complain about the first thing we found.
+ NamedDecl *Found = *Result.begin();
+ S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
+ return nullptr;
+ }
+
+ ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
+ if (DR.isInvalid())
+ return nullptr;
+
+ return DR.get();
+}
+
// Find an appropriate delete for the promise.
static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
QualType PromiseType) {
@@ -847,23 +880,51 @@
if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
return false;
- // FIXME: Add nothrow_t placement arg for global alloc
- // if ReturnStmtOnAllocFailure != nullptr.
+ const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
+
// FIXME: Add support for stateful allocators.
FunctionDecl *OperatorNew = nullptr;
FunctionDecl *OperatorDelete = nullptr;
FunctionDecl *UnusedResult = nullptr;
bool PassAlignment = false;
+ MultiExprArg PlacementArgs = None;
S.FindAllocationFunctions(Loc, SourceRange(),
/*UseGlobal*/ false, PromiseType,
- /*isArray*/ false, PassAlignment,
- /*PlacementArgs*/ None, OperatorNew, UnusedResult);
+ /*isArray*/ false, PassAlignment, PlacementArgs,
+ OperatorNew, UnusedResult);
- OperatorDelete = findDeleteForPromise(S, Loc, PromiseType);
+ bool IsGlobalOverload =
+ OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
+ // If we didn't find a class-local new declaration and non-throwing new
+ // was is required then we need to lookup the non-throwing global operator
+ // instead.
+ if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
+ auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
+ if (!StdNoThrow)
+ return false;
+ PlacementArgs = MultiExprArg(StdNoThrow);
+ OperatorNew = nullptr;
+ S.FindAllocationFunctions(Loc, SourceRange(),
+ /*UseGlobal*/ true, PromiseType,
+ /*isArray*/ false, PassAlignment, PlacementArgs,
+ OperatorNew, UnusedResult);
+ }
- if (!OperatorDelete || !OperatorNew)
+ if (OperatorNew && RequiresNoThrowAlloc) {
+ const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
+ if (!FT->isNothrow(S.Context, /*ResultIfDependent*/ false)) {
+ S.Diag(OperatorNew->getLocation(),
+ diag::err_coroutine_promise_new_requires_nothrow)
+ << OperatorNew;
+ S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
+ << OperatorNew;
+ return false;
+ }
+ }
+
+ if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
return false;
Expr *FramePtr =
@@ -879,8 +940,13 @@
if (NewRef.isInvalid())
return false;
+ SmallVector<Expr *, 2> NewArgs{FrameSize};
+ for (auto Arg : PlacementArgs)
+ NewArgs.push_back(Arg);
+
ExprResult NewExpr =
- S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, FrameSize, Loc);
+ S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
+ NewExpr = S.ActOnFinishFullExpr(NewExpr.get());
if (NewExpr.isInvalid())
return false;
@@ -906,6 +972,7 @@
ExprResult DeleteExpr =
S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
+ DeleteExpr = S.ActOnFinishFullExpr(DeleteExpr.get());
if (DeleteExpr.isInvalid())
return false;