Quuxplusone created this revision.
Quuxplusone added reviewers: sammccall, rsmith, dblaikie, mizvekov.
Quuxplusone added a project: clang.
Quuxplusone requested review of this revision.
Herald added a subscriber: cfe-commits.
This is a preliminary ahead of D119184 <https://reviews.llvm.org/D119184> (I'll
rebase that one on top of this). This shows what Clang's //current// behavior
is for various deduced-return-type situations. Then, in D119184
<https://reviews.llvm.org/D119184>, I'll be able to demonstrate exactly how the
diagnostics on each of these situations change.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D119772
Files:
clang/test/SemaCXX/deduced-return-void.cpp
Index: clang/test/SemaCXX/deduced-return-void.cpp
===================================================================
--- clang/test/SemaCXX/deduced-return-void.cpp
+++ clang/test/SemaCXX/deduced-return-void.cpp
@@ -4,20 +4,137 @@
// Check that we don't get any extra warning for "return" without an
// expression, in a function that might have been intended to return
// void all along.
-auto f1() {
- return 1;
- return; // expected-error {{deduced as 'void' here but deduced as 'int' in earlier return statement}}
+decltype(h1) h1() { // expected-error {{use of undeclared identifier 'h1'}}
+ return;
+}
+
+namespace JustAuto {
+int i;
+auto f1() { }
+auto f2() { return; }
+auto f3() { return void(); }
+auto f4() {
+ return i;
+ return; // expected-error {{'auto' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
+}
+auto f5() {
+ return i;
+ return void(); // expected-error {{'auto' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
}
-decltype(auto) f2() {
- return 1;
- return; // expected-error {{deduced as 'void' here but deduced as 'int' in earlier return statement}}
+auto l1 = []() { };
+auto l2 = []() { return; };
+auto l3 = []() { return void(); };
+auto l4 = []() {
+ return i;
+ return; // expected-error {{return type 'void' must match previous return type 'int' when lambda expression has unspecified explicit return type}}
+};
+auto l5 = []() {
+ return i;
+ return void(); // expected-error {{return type 'void' must match previous return type 'int' when lambda expression has unspecified explicit return type}}
+};
+
+} // namespace JustAuto
+
+namespace DecltypeAuto {
+int i;
+decltype(auto) f1() { }
+decltype(auto) f2() { return; }
+decltype(auto) f3() { return void(); }
+decltype(auto) f4() {
+ return i;
+ return; // expected-error {{'decltype(auto)' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
+}
+decltype(auto) f5() {
+ return i;
+ return void(); // expected-error {{'decltype(auto)' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
}
-auto *g() {
+auto l1 = []() -> decltype(auto) { };
+auto l2 = []() -> decltype(auto) { return; };
+auto l3 = []() -> decltype(auto) { return void(); };
+auto l4 = []() -> decltype(auto) {
+ return i;
+ return; // expected-error {{'decltype(auto)' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
+};
+auto l5 = []() -> decltype(auto) {
+ return i;
+ return void(); // expected-error {{'decltype(auto)' in return type deduced as 'void' here but deduced as 'int' in earlier return statement}}
+};
+
+} // namespace DecltypeAuto
+
+namespace AutoPtr {
+int i;
+auto *f1() { } // expected-error {{cannot deduce return type 'auto *' for function with no return statements}}
+auto *f2() {
+ return; // expected-error {{cannot deduce return type 'auto *' from omitted return expression}}
+}
+auto *f3() {
+ return void(); // expected-error {{cannot deduce return type 'auto *' from returned value of type 'void'}}
+}
+auto *f4() {
+ return &i;
return; // expected-error {{cannot deduce return type 'auto *' from omitted return expression}}
}
+auto *f5() {
+ return &i;
+ return void(); // expected-error {{cannot deduce return type 'auto *' from returned value of type 'void'}}
+}
-decltype(h1) h1() { // expected-error {{use of undeclared identifier 'h1'}}
- return;
+auto l1 = []() -> auto* { }; // expected-error {{cannot deduce return type 'auto *' for function with no return statements}}
+auto l2 = []() -> auto* {
+ return; // expected-error {{cannot deduce return type 'auto *' from omitted return expression}}
+};
+auto l3 = []() -> auto* {
+ return void(); // expected-error {{cannot deduce return type 'auto *' from returned value of type 'void'}}
+};
+auto l4 = []() -> auto* {
+ return &i;
+ return; // expected-error {{cannot deduce return type 'auto *' from omitted return expression}}
+};
+auto l5 = []() -> auto* {
+ return &i;
+ return void(); // expected-error {{cannot deduce return type 'auto *' from returned value of type 'void'}}
+};
+} // namespace AutoPtr
+
+namespace AutoRef {
+int i;
+auto& f1() { // expected-error {{cannot deduce return type 'auto &' for function with no return statements}}
+}
+auto& f2() {
+ return; // expected-error {{cannot deduce return type 'auto &' from omitted return expression}}
+}
+auto& f3() {
+ return void(); // expected-error@-1 {{cannot form a reference to 'void'}}
}
+auto& f4() {
+ return i;
+ return; // expected-error {{cannot deduce return type 'auto &' from omitted return expression}}
+}
+auto& f5() {
+ return i;
+ return void(); // expected-error@-2 {{cannot form a reference to 'void'}}
+}
+auto& f6() { return 42; } // expected-error {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
+
+auto l1 = []() -> auto& { }; // expected-error {{cannot deduce return type 'auto &' for function with no return statements}}
+auto l2 = []() -> auto& {
+ return; // expected-error {{cannot deduce return type 'auto &' from omitted return expression}}
+};
+auto l3 = []() -> auto& { // expected-error {{cannot form a reference to 'void'}}
+ return void();
+};
+auto l4 = []() -> auto& {
+ return i;
+ return; // expected-error {{cannot deduce return type 'auto &' from omitted return expression}}
+};
+auto l5 = []() -> auto& { // expected-error {{cannot form a reference to 'void'}}
+ return i;
+ return void();
+};
+auto l6 = []() -> auto& {
+ return 42; // expected-error {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
+};
+} // namespace AutoRef
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
