EricWF updated this revision to Diff 73715.
EricWF added a comment.
- Address @majnemer's comment about using `auto`.
https://reviews.llvm.org/D25292
Files:
include/clang/Basic/DiagnosticSemaKinds.td
lib/Sema/SemaCoroutine.cpp
test/SemaCXX/coroutines.cpp
Index: test/SemaCXX/coroutines.cpp
===================================================================
--- test/SemaCXX/coroutines.cpp
+++ test/SemaCXX/coroutines.cpp
@@ -167,7 +167,19 @@
}
// FIXME: The spec says this is ill-formed.
void operator=(CtorDtor&) {
- co_yield 0;
+ co_yield 0; // expected-error {{'co_yield' cannot be used in a copy assignment operator}}
+ }
+ void operator=(CtorDtor const &) {
+ co_yield 0; // expected-error {{'co_yield' cannot be used in a copy assignment operator}}
+ }
+ void operator=(CtorDtor &&) {
+ co_await a; // expected-error {{'co_await' cannot be used in a move assignment operator}}
+ }
+ void operator=(CtorDtor const &&) {
+ co_await a; // expected-error {{'co_await' cannot be used in a move assignment operator}}
+ }
+ void operator=(int) {
+ co_await a; // OK. Not a special member
}
};
@@ -180,14 +192,19 @@
typeid(co_yield a); // expected-error {{cannot be used in an unevaluated context}}
}
-constexpr void constexpr_coroutine() {
+constexpr auto constexpr_deduced_return_coroutine() {
co_yield 0; // expected-error {{'co_yield' cannot be used in a constexpr function}}
+ // expected-error@-1 {{'co_yield' cannot be used in a function with a deduced return type}}
}
void varargs_coroutine(const char *, ...) {
co_await a; // expected-error {{'co_await' cannot be used in a varargs function}}
}
+auto deduced_return_coroutine() {
+ co_await a; // expected-error {{'co_await' cannot be used in a function with a deduced return type}}
+}
+
struct outer {};
namespace dependent_operator_co_await_lookup {
@@ -303,6 +320,6 @@
template<> struct std::experimental::coroutine_traits<int, int, const char**>
{ using promise_type = promise; };
-int main(int, const char**) { // expected-error {{'main' cannot be a coroutine}}
- co_await a; // expected-note {{function is a coroutine due to use of 'co_await' here}}
+int main(int, const char**) {
+ co_await a; // expected-error {{'co_await' cannot be used in the 'main' function}}
}
Index: lib/Sema/SemaCoroutine.cpp
===================================================================
--- lib/Sema/SemaCoroutine.cpp
+++ lib/Sema/SemaCoroutine.cpp
@@ -99,67 +99,98 @@
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 if (FD->isMain()) {
- S.Diag(FD->getLocStart(), diag::err_coroutine_main);
- S.Diag(Loc, diag::note_declared_coroutine_here)
- << (Keyword == "co_await" ? 0 :
- Keyword == "co_yield" ? 1 : 2);
- } 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 ScopeInfo;
+ return false;
+ }
+
+ // 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;
}
/// Build a call to 'operator co_await' if there is a suitable operator for
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -8559,14 +8559,11 @@
"'%0' cannot be used in an unevaluated context">;
def err_coroutine_outside_function : Error<
"'%0' cannot be used outside a function">;
-def err_coroutine_ctor_dtor : Error<
- "'%1' cannot be used in a %select{constructor|destructor}0">;
-def err_coroutine_constexpr : Error<
- "'%0' cannot be used in a constexpr function">;
-def err_coroutine_main : Error<
- "'main' cannot be a coroutine">;
-def err_coroutine_varargs : Error<
- "'%0' cannot be used in a varargs function">;
+def err_coroutine_invalid_func_context : Error<
+ "'%1' cannot be used in %select{a constructor|a destructor"
+ "|a copy assignment operator|a move assignment operator|the 'main' function"
+ "|a constexpr function|a function with a deduced return type"
+ "|a varargs function}0">;
def ext_coroutine_without_co_await_co_yield : ExtWarn<
"'co_return' used in a function "
"that uses neither 'co_await' nor 'co_yield'">,
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