ec6da3fb9d
Before this change, the `NoReturnFunctionChecker` was missing function pointers with a `[[noreturn]]` attribute, while `CFG` was constructed taking that into account, which leads CSA to take impossible paths. The reason was that the `NoReturnFunctionChecker` was looking for the attribute in the type of the entire call expression rather than the type of the function being called. This change makes the `[[noreturn]]` attribute of a function pointer visible to `NoReturnFunctionChecker`. This leads to a more coherent behavior of the CSA on the AST involving. Reviewed By: xazax.hun Differential Revision: https://reviews.llvm.org/D135682
37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
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typedef void(fatal_fun)() __attribute__((__noreturn__));
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fatal_fun* fatal_fptr;
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void fatal_decl() __attribute__((__noreturn__));
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int rng();
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/// This code calls a [[noreturn]] function pointer, which used to be handled
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/// inconsistently between AST builder and CSA.
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/// In the result, CSA produces a path where this function returns non-0.
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int return_zero_or_abort_by_fnptr() {
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if (rng()) fatal_fptr();
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return 0;
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}
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/// This function calls a [[noreturn]] function.
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/// If it does return, it always returns 0.
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int return_zero_or_abort_by_direct_fun() {
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if (rng()) fatal_decl();
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return 0;
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}
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/// Trigger a division by zero issue depending on the return value
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/// of the called functions.
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int caller() {
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int x = 0;
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// The following if branches must never be taken.
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if (return_zero_or_abort_by_fnptr())
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return 1 / x; // no-warning: Dead code.
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if (return_zero_or_abort_by_direct_fun())
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return 1 / x; // no-warning: Dead code.
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// Make sure the warning is still reported when viable.
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return 1 / x; // expected-warning {{Division by zero}}
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}
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