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44 lines
1.3 KiB
Plaintext
44 lines
1.3 KiB
Plaintext
/**
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* @name Constant in conditional expression or statement
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* @description The conditional is always true or always false
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* @kind problem
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* @tags quality
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* maintainability
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* useless-code
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* external/cwe/cwe-561
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* external/cwe/cwe-570
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* external/cwe/cwe-571
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* @problem.severity warning
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* @sub-severity low
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* @precision very-high
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* @id py/constant-conditional-expression
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*/
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import python
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predicate is_condition(Expr cond) {
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exists(If i | i.getTest() = cond) or
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exists(IfExp ie | ie.getTest() = cond)
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}
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/* Treat certain unmodified builtins as constants as well. */
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predicate effective_constant(Name cond) {
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exists(GlobalVariable var | var = cond.getVariable() and not exists(NameNode f | f.defines(var)) |
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var.getId() = "True" or var.getId() = "False" or var.getId() = "NotImplemented"
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)
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}
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predicate test_makes_code_unreachable(Expr cond) {
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exists(If i | i.getTest() = cond | i.getStmt(0).isUnreachable() or i.getOrelse(0).isUnreachable())
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or
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exists(While w | w.getTest() = cond and w.getStmt(0).isUnreachable())
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}
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from Expr cond
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where
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is_condition(cond) and
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(cond.isConstant() or effective_constant(cond)) and
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/* Ignore cases where test makes code unreachable, as that is handled in different query */
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not test_makes_code_unreachable(cond)
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select cond, "Testing a constant will always give the same result."
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