[TS] Mock unresolved virtual calls instead of killing the state#342
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CaelmBleidd wants to merge 3 commits into
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[TS] Mock unresolved virtual calls instead of killing the state#342CaelmBleidd wants to merge 3 commits into
CaelmBleidd wants to merge 3 commits into
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Coverage investigation on an open-source corpus showed that 155 of 172 unreached symbolic targets died in under 100ms: TsInterpreter killed the state (assert(false)) on ANY unresolved callee (e.g. Number.isInteger), making everything after such a call unreachable. All three unresolved-call sites in visitVirtualMethodCall now fall back to mockMethodCall + returnSite, mirroring the pre-existing unresolved-constructor approximation. Full usvm-ts suite stays green (422 tests). NOTE: an engine fix, staged to be extracted into a separate PR.
Front ends lower the side effect of `x++`/`--x` into an explicit
assignment (the native ts-frontend emits `%t := x; x := ++x`, ArkAnalyzer
expands to `x := x + 1`), and the jacodb DTO conversion maps both `++` and
`--` to the Pre* model classes only. The resolver previously crashed on
them ("Not supported"), killing every state in loops written with
`x--`/`--x` under the ts-frontend. Pre* now evaluate to ToNumber(arg) +- 1
and Post* (never produced by the converter, but part of the model) to the
old value.
Tests: direct machine tests over programmatically built IR (ArkAnalyzer
cannot exercise these visits since it never emits the unary forms) plus an
ArkAnalyzer-lowered sample. A `const old = x++` sample case is deliberately
absent: ArkAnalyzer lowers it as `x := x + 1; old := x`, i.e. `old`
receives the new value - a frontend lowering bug found while writing these
tests.
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
| @Test | ||
| fun `pre-increment yields arg plus one`() { | ||
| for ((input, result) in run("preInc") { EtsPreIncExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) |
| fun `pre-increment yields arg plus one`() { | ||
| for ((input, result) in run("preInc") { EtsPreIncExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) | ||
| else assertEquals(input + 1, result, 0.0) { "++($input)" } |
| @Test | ||
| fun `pre-decrement yields arg minus one`() { | ||
| for ((input, result) in run("preDec") { EtsPreDecExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) |
| fun `pre-decrement yields arg minus one`() { | ||
| for ((input, result) in run("preDec") { EtsPreDecExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) | ||
| else assertEquals(input - 1, result, 0.0) { "--($input)" } |
| @Test | ||
| fun `post-increment and post-decrement yield the old value`() { | ||
| for ((input, result) in run("postInc") { EtsPostIncExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) |
| fun `post-increment and post-decrement yield the old value`() { | ||
| for ((input, result) in run("postInc") { EtsPostIncExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) | ||
| else assertEquals(input, result, 0.0) { "($input)++" } |
| else assertEquals(input, result, 0.0) { "($input)++" } | ||
| } | ||
| for ((input, result) in run("postDec") { EtsPostDecExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) |
| } | ||
| for ((input, result) in run("postDec") { EtsPostDecExpr(it, EtsNumberType) }) { | ||
| if (input.isNaN()) assertTrue(result.isNaN()) | ||
| else assertEquals(input, result, 0.0) { "($input)--" } |
…lback Frequency data from open-source corpora (TheAlgorithms/TypeScript maths and loiane/javascript-datastructures-algorithms, full-log probes) shows that unresolved calls split into three groups: in-project cross-file targets (a scene-construction problem, not the engine's), a small set of very hot builtins (Math.abs — 208 occurrences, Number.isInteger — 55, Math.sqrt — 13 on the maths corpus alone), and a tail of genuinely unmodelable calls. This change shrinks the over-approximation surface of the mock fallback by modeling the hot builtins precisely in the fp theory: - Number.isInteger / isSafeInteger (2^53 bound not modeled) / isFinite, with the same fake-object discriminator handling as Number.isNaN - Math.floor/ceil/trunc via fp round-to-integral in the matching mode (floor generalized), Math.round as floor(x + 0.5) per JS semantics, Math.abs, Math.sqrt - Math.min/max with JS NaN semantics (NaN if any argument is NaN, unlike IEEE minNum/maxNum) - console.* treated as side-effect-free undefined, like Logger Every remaining mock fallback now logs a distinct "Mocking an unresolved call: <callee> (over-approximation)" line, so the residual over-approximation stays measurable on corpus runs. decrementLoop test properties are reclassified by the observed loop depth: non-integral inputs (n = 2.5) legitimately reach depth ceil(n), and the solver started picking such models once the approximations changed the search.
| "Math.${expr.callee.name}() should have exactly one argument, but got ${expr.args.size}" | ||
| } | ||
| val arg = resolve(expr.args.single()) ?: return null | ||
| when { |
| val plusHalf = mkFpAddExpr( | ||
| mkFpRoundingModeExpr(KFpRoundingMode.RoundNearestTiesToEven), | ||
| value, | ||
| mkFp64(0.5), |
| private fun TsExprResolver.handleMathMinMax(expr: EtsInstanceCallExpr, isMin: Boolean): UExpr<*>? = with(ctx) { | ||
| val args = expr.args.map { arg -> | ||
| val resolved = resolve(arg) ?: return null | ||
| when { |
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Coverage investigation on an open-source corpus showed that 155 of 172 unreached symbolic targets died in under 100ms: TsInterpreter killed the state (assert(false)) on ANY unresolved callee (e.g. Number.isInteger), making everything after such a call unreachable. All three unresolved-call sites in visitVirtualMethodCall now fall back to mockMethodCall + returnSite, mirroring the pre-existing unresolved-constructor approximation. Full usvm-ts suite stays green (422 tests).
NOTE: an engine fix, staged to be extracted into a separate PR.