llvm-for-llvmta/unittests/Support/ErrorOrTest.cpp

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//===- unittests/ErrorOrTest.cpp - ErrorOr.h tests ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/Errc.h"
#include "gtest/gtest.h"
#include <memory>
using namespace llvm;
namespace {
ErrorOr<int> t1() { return 1; }
ErrorOr<int> t2() { return errc::invalid_argument; }
TEST(ErrorOr, SimpleValue) {
ErrorOr<int> a = t1();
// FIXME: This is probably a bug in gtest. EXPECT_TRUE should expand to
// include the !! to make it friendly to explicit bool operators.
EXPECT_TRUE(!!a);
EXPECT_EQ(1, *a);
ErrorOr<int> b = a;
EXPECT_EQ(1, *b);
a = t2();
EXPECT_FALSE(a);
EXPECT_EQ(a.getError(), errc::invalid_argument);
#ifdef EXPECT_DEBUG_DEATH
EXPECT_DEBUG_DEATH(*a, "Cannot get value when an error exists");
#endif
}
ErrorOr<std::unique_ptr<int> > t3() {
return std::unique_ptr<int>(new int(3));
}
TEST(ErrorOr, Types) {
int x;
ErrorOr<int&> a(x);
*a = 42;
EXPECT_EQ(42, x);
// Move only types.
EXPECT_EQ(3, **t3());
}
struct B {};
struct D : B {};
TEST(ErrorOr, Covariant) {
ErrorOr<B*> b(ErrorOr<D*>(nullptr));
b = ErrorOr<D*>(nullptr);
ErrorOr<std::unique_ptr<B> > b1(ErrorOr<std::unique_ptr<D> >(nullptr));
b1 = ErrorOr<std::unique_ptr<D> >(nullptr);
ErrorOr<std::unique_ptr<int>> b2(ErrorOr<int *>(nullptr));
ErrorOr<int *> b3(nullptr);
ErrorOr<std::unique_ptr<int>> b4(b3);
}
TEST(ErrorOr, Comparison) {
ErrorOr<int> x(errc::no_such_file_or_directory);
EXPECT_EQ(x, errc::no_such_file_or_directory);
}
TEST(ErrorOr, ImplicitConversion) {
ErrorOr<std::string> x("string literal");
EXPECT_TRUE(!!x);
}
TEST(ErrorOr, ImplicitConversionCausesMove) {
struct Source {};
struct Destination {
Destination(const Source&) {}
Destination(Source&&) = delete;
};
Source s;
ErrorOr<Destination> x = s;
EXPECT_TRUE(!!x);
}
TEST(ErrorOr, ImplicitConversionNoAmbiguity) {
struct CastsToErrorCode {
CastsToErrorCode() = default;
CastsToErrorCode(std::error_code) {}
operator std::error_code() { return errc::invalid_argument; }
} casts_to_error_code;
ErrorOr<CastsToErrorCode> x1(casts_to_error_code);
ErrorOr<CastsToErrorCode> x2 = casts_to_error_code;
ErrorOr<CastsToErrorCode> x3 = {casts_to_error_code};
ErrorOr<CastsToErrorCode> x4{casts_to_error_code};
ErrorOr<CastsToErrorCode> x5(errc::no_such_file_or_directory);
ErrorOr<CastsToErrorCode> x6 = errc::no_such_file_or_directory;
ErrorOr<CastsToErrorCode> x7 = {errc::no_such_file_or_directory};
ErrorOr<CastsToErrorCode> x8{errc::no_such_file_or_directory};
EXPECT_TRUE(!!x1);
EXPECT_TRUE(!!x2);
EXPECT_TRUE(!!x3);
EXPECT_TRUE(!!x4);
EXPECT_FALSE(x5);
EXPECT_FALSE(x6);
EXPECT_FALSE(x7);
EXPECT_FALSE(x8);
}
// ErrorOr<int*> x(nullptr);
// ErrorOr<std::unique_ptr<int>> y = x; // invalid conversion
static_assert(
!std::is_convertible<const ErrorOr<int *> &,
ErrorOr<std::unique_ptr<int>>>::value,
"do not invoke explicit ctors in implicit conversion from lvalue");
// ErrorOr<std::unique_ptr<int>> y = ErrorOr<int*>(nullptr); // invalid
// // conversion
static_assert(
!std::is_convertible<ErrorOr<int *> &&,
ErrorOr<std::unique_ptr<int>>>::value,
"do not invoke explicit ctors in implicit conversion from rvalue");
// ErrorOr<int*> x(nullptr);
// ErrorOr<std::unique_ptr<int>> y;
// y = x; // invalid conversion
static_assert(!std::is_assignable<ErrorOr<std::unique_ptr<int>>&,
const ErrorOr<int *> &>::value,
"do not invoke explicit ctors in assignment");
// ErrorOr<std::unique_ptr<int>> x;
// x = ErrorOr<int*>(nullptr); // invalid conversion
static_assert(!std::is_assignable<ErrorOr<std::unique_ptr<int>>&,
ErrorOr<int *> &&>::value,
"do not invoke explicit ctors in assignment");
} // end anon namespace