f7f2e4261a
callee in constant evaluation. We previously made a deep copy of function parameters of class type when passing them, resulting in the destructor for the parameter applying to the original argument value, ignoring any modifications made in the function body. This also meant that the 'this' pointer of the function parameter could be observed changing between the caller and the callee. This change completely reimplements how we model function parameters during constant evaluation. We now model them roughly as if they were variables living in the caller, albeit with an artificially reduced scope that covers only the duration of the function call, instead of modeling them as temporaries in the caller that we partially "reparent" into the callee at the point of the call. This brings some minor diagnostic improvements, as well as significantly reduced stack usage during constant evaluation.
59 lines
2.8 KiB
C++
59 lines
2.8 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -verify %s
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__attribute__((noreturn)) extern void bar();
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int test_no_warn(int x) {
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if (x) {
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if (__builtin_expect_with_probability(1, 1, 1))
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bar();
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} else {
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return 0;
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}
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} // should not emit warn "control may reach end of non-void function" here since expr is constantly true, so the "if(__bui..)" should be constantly true condition and be ignored
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template <int b> void tempf() {
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static_assert(b == 1, "should be evaluated as 1"); // should not have error here
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}
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constexpr int constf() {
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return __builtin_expect_with_probability(1, 1, 1);
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}
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void foo() {
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tempf<__builtin_expect_with_probability(1, 1, 1)>();
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constexpr int f = constf();
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static_assert(f == 1, "should be evaluated as 1"); // should not have error here
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}
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extern int global;
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struct S {
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static constexpr float prob = 0.7;
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};
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template<typename T>
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void expect_taken(int x) {
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if (__builtin_expect_with_probability(x > 0, 1, T::prob)) {
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global++;
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}
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}
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void test(int x, double p) { // expected-note {{declared here}}
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bool dummy;
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dummy = __builtin_expect_with_probability(x > 0, 1, 0.9);
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dummy = __builtin_expect_with_probability(x > 0, 1, 1.1); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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dummy = __builtin_expect_with_probability(x > 0, 1, -1); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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dummy = __builtin_expect_with_probability(x > 0, 1, p); // expected-error {{probability argument to __builtin_expect_with_probability must be constant floating-point expression}} expected-note {{function parameter 'p'}}
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dummy = __builtin_expect_with_probability(x > 0, 1, "aa"); // expected-error {{cannot initialize a parameter of type 'double' with an lvalue of type 'const char [3]'}}
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dummy = __builtin_expect_with_probability(x > 0, 1, __builtin_nan("")); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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dummy = __builtin_expect_with_probability(x > 0, 1, __builtin_inf()); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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dummy = __builtin_expect_with_probability(x > 0, 1, -0.0);
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dummy = __builtin_expect_with_probability(x > 0, 1, 1.0 + __DBL_EPSILON__); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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dummy = __builtin_expect_with_probability(x > 0, 1, -__DBL_DENORM_MIN__); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
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constexpr double pd = 0.7;
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dummy = __builtin_expect_with_probability(x > 0, 1, pd);
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constexpr int pi = 1;
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dummy = __builtin_expect_with_probability(x > 0, 1, pi);
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expect_taken<S>(x);
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}
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