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Add underlining to safe-init stack traces
This underlines the source positions in the safe-init stack traces similarly to how the MessageRendering will underline its stack positions. Before, a safe-init error might look like this: ``` [error] -- Error: /******/dotty/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala:1032:22 [error] 1032 | "inlineVars" -> inlineVars [error] | ^^^^^^^^^^ [error] |Cannot prove that the value is fully initialized. Only initialized values may be used as arguments [error] | [error] |The unsafe promotion may cause the following problem: [error] |Calling the external method method apply may cause initialization errors. Calling trace: [error] | -> "inlineVars" -> inlineVars [ PatternMatcher.scala:1032 ] [error] | -> Inliner(plan) [ PatternMatcher.scala:700 ] [error] | -> case plan: TestPlan => apply(plan) [ PatternMatcher.scala:492 ] [error] | -> plan.scrutinee = apply(plan.scrutinee) [ PatternMatcher.scala:472 ] [error] | -> def apply(tree: Tree): Tree = treeMap.transform(tree) [ PatternMatcher.scala:470 ] [error] | -> if (toDrop(sym)) transform(initializer(sym)) [ PatternMatcher.scala:675 ] ``` Now, the same error looks like this: ``` [error] -- Error: /******/dotty/compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala:1032:22 [error] 1032 | "inlineVars" -> inlineVars [error] | ^^^^^^^^^^ [error] |Cannot prove that the value is fully initialized. Only initialized values may be used as arguments [error] | [error] |The unsafe promotion may cause the following problem: [error] |Calling the external method method apply may cause initialization errors. Calling trace: [error] | -> "inlineVars" -> inlineVars [ PatternMatcher.scala:1032 ] [error] | ^^^^^^^^^^ [error] | -> Inliner(plan) [ PatternMatcher.scala:700 ] [error] | ^^^^^^^^^^^^^ [error] | -> case plan: TestPlan => apply(plan) [ PatternMatcher.scala:492 ] [error] | ^^^^^^^^^^^ [error] | -> plan.scrutinee = apply(plan.scrutinee) [ PatternMatcher.scala:472 ] [error] | ^^^^^^^^^^^^^^^^^^^^^ [error] | -> def apply(tree: Tree): Tree = treeMap.transform(tree) [ PatternMatcher.scala:470 ] [error] | ^^^^^^^^^^^^^^^^^^^^^^^ [error] | -> if (toDrop(sym)) transform(initializer(sym)) [ PatternMatcher.scala:675 ] ``` This should improve the readability of the safe-init error messages. Review by @liufengyun
1 parent 5626f25 commit 0cfbd11

12 files changed

+55
-1
lines changed

‎compiler/src/dotty/tools/dotc/transform/init/Errors.scala

+20-1
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@@ -5,6 +5,7 @@ package init
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import ast.tpd._
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import core._
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import util.SourcePosition
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import Decorators._, printing.SyntaxHighlighting
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import Types._, Symbols._, Contexts._
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@@ -40,14 +41,32 @@ object Errors {
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i"$code\t$loc"
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else
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tree.show
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val positionMarkerLine =
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if pos.exists && pos.source.exists then
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positionMarker(pos, indentCount + 3)
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else ""
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if (last != line) sb.append(prefix + line + "\n")
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if (last != line) sb.append(prefix + line + "\n" + positionMarkerLine )
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last = line
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}
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sb.toString
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}
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/** Used to underline source positions in the stack trace
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* pos.source must exist
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*/
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private def positionMarker(pos: SourcePosition, indent: Int): String = {
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val trimmed = pos.lineContent.takeWhile(c => c.isWhitespace).length
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val padding = pos.startColumnPadding.substring(trimmed).nn + (" " * indent)
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val carets =
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if (pos.startLine == pos.endLine)
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"^" * math.max(1, pos.endColumn - pos.startColumn)
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else "^"
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s"$padding$carets\n"
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}
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/** Flatten UnsafePromotion errors
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*/
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def flatten: Errors = this match {

‎tests/init/neg/cycle-structure.check

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@@ -3,12 +3,18 @@
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| ^^^
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| Access field A.this.b.x on a value with an unknown initialization status. Calling trace:
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| -> val x = A(this) [ cycle-structure.scala:9 ]
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| ^^^^^^^
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| -> case class A(b: B) { [ cycle-structure.scala:1 ]
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| ^
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-- Error: tests/init/neg/cycle-structure.scala:8:15 --------------------------------------------------------------------
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8 | val x1 = a.x // error
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| ^^^
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| Access field B.this.a.x on a value with an unknown initialization status. Calling trace:
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| -> val x = A(this) [ cycle-structure.scala:9 ]
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| ^^^^^^^
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| -> case class A(b: B) { [ cycle-structure.scala:1 ]
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| ^
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| -> val x = B(this) [ cycle-structure.scala:3 ]
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| ^^^^^^^
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| -> case class B(a: A) { [ cycle-structure.scala:7 ]
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| ^

‎tests/init/neg/default-this.check

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@@ -3,3 +3,4 @@
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| ^^^^^^^
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|Cannot prove that the value is fully initialized. Only initialized values may be used as arguments. Calling trace:
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| -> val result = updateThenCompare(5) [ default-this.scala:11 ]
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| ^^^^^^^^^^^^^^^^^^^^

‎tests/init/neg/enum-desugared.check

+4
Original file line numberDiff line numberDiff line change
@@ -6,7 +6,9 @@
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| The unsafe promotion may cause the following problem:
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| Calling the external method method name may cause initialization errors. Calling trace:
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| -> Array(this.LazyErrorId, this.NoExplanationID) // error // error [ enum-desugared.scala:17 ]
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| ^^^^^^^^^^^^^^^^
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| -> override def productPrefix: String = this.name() [ enum-desugared.scala:29 ]
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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-- Error: tests/init/neg/enum-desugared.scala:17:33 --------------------------------------------------------------------
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17 | Array(this.LazyErrorId, this.NoExplanationID) // error // error
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| ^^^^^^^^^^^^^^^^^^^^
@@ -15,4 +17,6 @@
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| The unsafe promotion may cause the following problem:
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| Calling the external method method ordinal may cause initialization errors. Calling trace:
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| -> Array(this.LazyErrorId, this.NoExplanationID) // error // error [ enum-desugared.scala:17 ]
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| ^^^^^^^^^^^^^^^^^^^^
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| -> def errorNumber: Int = this.ordinal() - 2 [ enum-desugared.scala:8 ]
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

‎tests/init/neg/enum.check

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@@ -6,3 +6,4 @@
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| The unsafe promotion may cause the following problem:
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| Calling the external method method name may cause initialization errors. Calling trace:
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| -> NoExplanationID // error [ enum.scala:4 ]
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| ^

‎tests/init/neg/inherit-non-hot.check

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@@ -4,13 +4,21 @@
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| Cannot prove that the value is fully initialized. May only assign fully initialized value.
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| Calling trace:
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| -> val c = new C [ inherit-non-hot.scala:19 ]
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| ^^^^^
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| -> class C extends A { [ inherit-non-hot.scala:15 ]
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| ^
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| -> val bAgain = toB.getBAgain [ inherit-non-hot.scala:16 ]
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| ^^^
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|
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| The unsafe promotion may cause the following problem:
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| Call method Foo.B.this.aCopy.toB on a value with an unknown initialization. Calling trace:
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| -> val c = new C [ inherit-non-hot.scala:19 ]
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| ^^^^^
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| -> class C extends A { [ inherit-non-hot.scala:15 ]
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| ^
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| -> val bAgain = toB.getBAgain [ inherit-non-hot.scala:16 ]
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| ^^^
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| -> if b == null then b = new B(this) // error [ inherit-non-hot.scala:6 ]
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| ^^^^^^^^^^^
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| -> def getBAgain: B = aCopy.toB [ inherit-non-hot.scala:12 ]
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

‎tests/init/neg/inlined-method.check

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@@ -3,3 +3,4 @@
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| ^^^^^^^
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|Cannot prove that the value is fully initialized. Only initialized values may be used as arguments. Calling trace:
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| -> Assertion.failAssert(this) [ inlined-method.scala:2 ]
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^

‎tests/init/neg/local-warm4.check

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@@ -3,9 +3,16 @@
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| ^^^^
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| Cannot prove that the value is fully initialized. May only assign fully initialized value. Calling trace:
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| -> val a = new A(5) [ local-warm4.scala:26 ]
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| ^^^^^^^^
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| -> class A(x: Int) extends Foo(x) { [ local-warm4.scala:6 ]
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| ^
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| -> val b = new B(y) [ local-warm4.scala:10 ]
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| ^^^^^^^^
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| -> class B(x: Int) extends A(x) { [ local-warm4.scala:13 ]
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| ^
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| -> class A(x: Int) extends Foo(x) { [ local-warm4.scala:6 ]
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| ^
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| -> increment() [ local-warm4.scala:9 ]
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| ^^^^^^^^^^^
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| -> updateA() [ local-warm4.scala:21 ]
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| ^^^^^^^^^

‎tests/init/neg/t3273.check

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@@ -6,6 +6,7 @@
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| The unsafe promotion may cause the following problem:
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| Access non-initialized value num1. Calling trace:
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| -> val num1: LazyList[Int] = 1 #:: num1.map(_ + 1) // error [ t3273.scala:4 ]
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| ^^^^
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-- Error: tests/init/neg/t3273.scala:5:61 ------------------------------------------------------------------------------
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5 | val num2: LazyList[Int] = 1 #:: num2.iterator.map(_ + 1).to(LazyList) // error
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -14,3 +15,4 @@
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| The unsafe promotion may cause the following problem:
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| Access non-initialized value num2. Calling trace:
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| -> val num2: LazyList[Int] = 1 #:: num2.iterator.map(_ + 1).to(LazyList) // error [ t3273.scala:5 ]
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| ^^^^

‎tests/init/neg/unsound2.check

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@@ -3,4 +3,6 @@
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| ^^^
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| Access field B.this.a.n on a value with an unknown initialization status. Calling trace:
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| -> println(foo(x).getB) [ unsound2.scala:8 ]
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| ^^^^^^
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| -> def foo(y: Int): B = if (y > 10) then B(bar(y - 1), foo(y - 1).getN) else B(bar(y), 10) [ unsound2.scala:2 ]
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| ^^^^^^^^^^^^^^^

‎tests/init/neg/unsound3.check

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@@ -3,3 +3,4 @@
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| ^^^^^^^^^^^^^^
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| Access field C.this.foo().getC().b on a value with an unknown initialization status. Calling trace:
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| -> val b = foo() [ unsound3.scala:12 ]
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| ^^^^^

‎tests/init/neg/unsound4.check

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@@ -3,4 +3,6 @@
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| ^
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| Access non-initialized value aAgain. Calling trace:
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| -> val aAgain = foo(5) // error [ unsound4.scala:3 ]
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| ^^^^^^
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| -> def foo(x: Int): A = if (x < 5) then this else foo(x - 1).aAgain [ unsound4.scala:2 ]
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| ^^^^^^^^^^^^^^^^^

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