Tianyu Geng
c7272f6986
Currently DFA does not set "definitely equal to null" for access to variables that got assigned `null`. For example, FIR should mark the following line as SENSELESS_COMPARISON due to `s = null` above. https://github.com/JetBrains/kotlin/blob/d1531f9cdd5852352c0133198706125dc63b6007/compiler/testData/diagnostics/tests/smartCasts/alwaysNull.fir.kt#L6 The problem is at https://github.com/JetBrains/kotlin/blob/7e9f27436a77de1c76e3705da7aa1fbe8938336b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt#L1104 For null assignment, ideally the type should be `Nothing?`. This is addressed in a followup commit instead.
23 lines
443 B
Kotlin
Vendored
23 lines
443 B
Kotlin
Vendored
fun foo(): String {
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var s: String?
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s = null
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s?.length
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s<!UNSAFE_CALL!>.<!>length
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if (<!SENSELESS_COMPARISON!>s == null<!>) return s!!
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var t: String? = "y"
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if (t == null) t = "x"
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var x: Int? = null
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if (x == null) <!ASSIGNMENT_TYPE_MISMATCH!>x += null<!>
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return t + s
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}
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fun String?.gav() {}
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fun bar(s: String?) {
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if (s != null) return
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s.gav()
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s as? String
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s as String?
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s as String
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}
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