Fix checks for signed overflow #207
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The previous code checked for signed overflow on +, -, and * by doing the operation and checking the result, which can invoke undefined behavior. This replaces that code with initial tests on the operands. In addition, a test for the sole integer division overflow case (that is not division by zero) was missing: INT_MIN / -1 It has now been added, along with a test case.
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While reviewing this old PR I realized that we don't handle |
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When verifying that code being preprocessed does not invoke undefined behavior, Wave does it itself.
This change performs tests on the operands in advance, instead.
Tests
t_6_15,t_6_17, andt_6_18(though nott_6_17, for some reason) signal errors in the absence of this fix with-fsanitize=signed-integer-overflowconfigured, but it does not cause the tests to fail, because these tests are expected to exit with an error anyway.If merged, this will fix #197