llvm-project/clang/test/SemaCXX/warn-unreachable.cpp

110 lines
2.2 KiB
C++

// RUN: %clang_cc1 %s -fcxx-exceptions -fexceptions -fsyntax-only -verify -fblocks -Wunreachable-code -Wno-unused-value
int &halt() __attribute__((noreturn));
int &live();
int dead();
int liveti() throw(int);
int (*livetip)() throw(int);
int test1() {
try {
live();
} catch (int i) {
live();
}
return 1;
}
void test2() {
try {
live();
} catch (int i) {
live();
}
try {
liveti();
} catch (int i) {
live();
}
try {
livetip();
} catch (int i) {
live();
}
throw 1;
dead(); // expected-warning {{will never be executed}}
}
void test3() {
halt()
--; // expected-warning {{will never be executed}}
// FIXME: The unreachable part is just the '?', but really all of this
// code is unreachable and shouldn't be separately reported.
halt() // expected-warning {{will never be executed}}
?
dead() : dead();
live(),
float
(halt()); // expected-warning {{will never be executed}}
}
void test4() {
struct S {
int mem;
} s;
S &foor();
halt(), foor()// expected-warning {{will never be executed}}
.mem;
}
void test5() {
struct S {
int mem;
} s;
S &foonr() __attribute__((noreturn));
foonr()
.mem; // expected-warning {{will never be executed}}
}
void test6() {
struct S {
~S() { }
S(int i) { }
};
live(),
S
(halt()); // expected-warning {{will never be executed}}
}
// Don't warn about unreachable code in template instantiations, as
// they may only be unreachable in that specific instantiation.
void isUnreachable();
template <typename T> void test_unreachable_templates() {
T::foo();
isUnreachable(); // no-warning
}
struct TestUnreachableA {
static void foo() __attribute__((noreturn));
};
struct TestUnreachableB {
static void foo();
};
void test_unreachable_templates_harness() {
test_unreachable_templates<TestUnreachableA>();
test_unreachable_templates<TestUnreachableB>();
}
// Do warn about explict template specializations, as they represent
// actual concrete functions that somebody wrote.
template <typename T> void funcToSpecialize() {}
template <> void funcToSpecialize<int>() {
halt();
dead(); // expected-warning {{will never be executed}}
}