fb6deeb984
Rather than sprinkle calls to DiagnoseUnusedExprResult() around in places where we want diagnostics, we now diagnose unused expression statements and full expressions in a more generic way when acting on the final expression statement. This results in more appropriate diagnostics for [[nodiscard]] where we were previously lacking them, such as when the body of a for loop is not a compound statement. This patch fixes PR39837. llvm-svn: 350404
52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
// RUN: %clang_cc1 -std=c++1z -verify %s -Wno-vexing-parse
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int g, h;
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typedef int T;
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int f() {
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// init-statement declarations
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if (T n = 0; n != 0) {}
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if (T f(); f()) {}
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if (T(f()); f()) {}
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if (T(f()), g, h; f()) {}
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if (T f(); f()) {}
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if (T f(), g, h; f()) {}
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if (T(n) = 0; n) {}
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// init-statement expressions
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if (T{f()}; f()) {} // expected-warning {{expression result unused}}
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if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
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if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
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// condition declarations
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if (T(n){g}) {}
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if (T f()) {} // expected-error {{function type}}
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if (T f(), g, h) {} // expected-error {{function type}}
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if (T(n) = 0) {}
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// condition expressions
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if (T(f())) {}
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if (T{f()}) {}
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if (T(f()), g, h) {} // expected-warning 2{{unused}}
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if (T{f()}, g, h) {} // expected-warning 2{{unused}}
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// none of the above, disambiguated as expression (can't be a declaration)
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if (T(n)(g)) {} // expected-error {{undeclared identifier 'n'}}
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if (T(n)(int())) {} // expected-error {{undeclared identifier 'n'}}
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// Likewise for 'switch'
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switch (int n; n) {}
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switch (g; int g = 5) {} // expected-warning {{expression result unused}}
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if (int a, b; int c = a) { // expected-note 6{{previous}}
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int a; // expected-error {{redefinition}}
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int b; // expected-error {{redefinition}}
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int c; // expected-error {{redefinition}}
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} else {
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int a; // expected-error {{redefinition}}
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int b; // expected-error {{redefinition}}
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int c; // expected-error {{redefinition}}
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}
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return 0;
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}
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