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.
22 lines
461 B
Kotlin
Vendored
22 lines
461 B
Kotlin
Vendored
// See KT-969
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fun f() {
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var s: String?
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s = "a"
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var s1 = "" // String � ?
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if (<!SENSELESS_COMPARISON!>s != null<!>) { // Redundant
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s1.length
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// We can do smartcast here and below
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s1 = s.toString() // return String?
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s1.length
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s1 = s
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s1.length
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// It's just an assignment without smartcast
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val s2 = s
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// But smartcast can be done here
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s2.length
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// And also here
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val s3 = s.toString()
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s3.length
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}
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}
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