| 1 | //===- llvm/unittest/ADT/FunctionRefTest.cpp - function_ref unit tests ----===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "llvm/ADT/STLExtras.h" |
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| 10 | #include "gtest/gtest.h" |
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| 11 | |
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| 12 | using namespace llvm; |
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| 13 | |
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| 14 | namespace { |
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| 15 | |
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| 16 | // Ensure that there is a default constructor and we can test for a null |
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| 17 | // function_ref. |
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| 18 | TEST(FunctionRefTest, Null) { |
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| 19 | function_ref<int()> F; |
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| 20 | EXPECT_FALSE(F); |
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| 21 | |
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| 22 | auto L = [] { return 1; }; |
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| 23 | F = L; |
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| 24 | EXPECT_TRUE(F); |
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| 25 | |
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| 26 | F = {}; |
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| 27 | EXPECT_FALSE(F); |
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| 28 | } |
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| 29 | |
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| 30 | // Ensure that copies of a function_ref copy the underlying state rather than |
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| 31 | // causing one function_ref to chain to the next. |
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| 32 | TEST(FunctionRefTest, Copy) { |
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| 33 | auto A = [] { return 1; }; |
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| 34 | auto B = [] { return 2; }; |
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| 35 | function_ref<int()> X = A; |
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| 36 | function_ref<int()> Y = X; |
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| 37 | X = B; |
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| 38 | EXPECT_EQ(1, Y()); |
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| 39 | } |
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| 40 | |
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| 41 | TEST(FunctionRefTest, BadCopy) { |
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| 42 | auto A = [] { return 1; }; |
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| 43 | function_ref<int()> X; |
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| 44 | function_ref<int()> Y = A; |
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| 45 | function_ref<int()> Z = static_cast<const function_ref<int()> &&>(Y); |
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| 46 | X = Z; |
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| 47 | Y = nullptr; |
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| 48 | ASSERT_EQ(1, X()); |
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| 49 | } |
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| 50 | |
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| 51 | // Test that overloads on function_refs are resolved as expected. |
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| 52 | std::string returns(StringRef) { return "not a function" ; } |
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| 53 | std::string returns(function_ref<double()> F) { return "number" ; } |
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| 54 | std::string returns(function_ref<StringRef()> F) { return "string" ; } |
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| 55 | |
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| 56 | TEST(FunctionRefTest, SFINAE) { |
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| 57 | EXPECT_EQ("not a function" , returns("boo!" )); |
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| 58 | EXPECT_EQ("number" , returns([] { return 42; })); |
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| 59 | EXPECT_EQ("string" , returns([] { return "hello" ; })); |
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| 60 | } |
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| 61 | |
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| 62 | } // namespace |
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| 63 | |
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