Fix generated-class source attribution in MAL, LAL and OAL

[wu-sheng]

Fix generated-class source attribution in MAL, LAL and OAL

When generated DSL code throws, the stack frame should name the file it came from, the line inside that file, and the line of the rule that produced it. All three were broken.

at ...rt.envoy_ca_L41_service_listener_ssl_ca_expiration_seconds.run(
       envoy_ca_L41_service_listener_ssl_ca_expiration_seconds.java:12)
                └─┬─┘                                          └───┬───┘  └┬┘
      envoy-ca.yaml line 41                              a real file    line 12

broken	fix
_L<n> was the rules-list index, so every file's first rule read L0	the rule's real YAML line
SourceFile named a file that was never written	names the sidecar actually on disk
LineNumberTable held statement ordinals	MAL maps each statement to its real sidecar line

Fixing any two of the three leaves the frame useless, which is why the class-naming issue is part of this rather than cosmetic.

Closure companions

A companion always claimed a source file — Javassist stamps SourceFile unconditionally — but the file was never written: 84 dangling references in network-profiling alone. Each now writes its own sidecar and carries one entry at its SAM signature. One entry is derived, not conceded: the statement scanner marks boundaries at stores to a result slot, which a closure body never makes. On the shipped rule set 96% of companions would collapse to one entry regardless, while the forEach ones over-count — 8 boundaries for 5 statements.

0/24 → 24/24 companions with a resolvable sidecar and a line table.

LAL and OAL

Same defect: both stamped (execution-basic.yaml:304)auto-layer-not-set.java while writing execution_basic_L304_auto_layer_not_set.java. The provenance format is what made it convincing — it reads as more informative than a bare file name, which is why nobody noticed it addressed nothing. LAL: 0/48 → 48/48 resolvable.

Their line tables are removed rather than corrected. Their statements are void invocations that store nothing, so MAL's boundary detector finds nothing, and the stack-depth alternative is unsound (the probe's ifeq consumes its operand mid-statement). While SourceFile dangled, an ordinal was inert; once it resolves, an ordinal resolves too — to the sidecar's comment header. A single signature-line entry for them is a follow-up.

Both sidecar writers also moved off a platform-default FileWriter with a non-ASCII header — the pairing that produced MalformedInputException for MAL on this branch.

• Add a unit test to verify that the fix works.
• Explain briefly why the bug exists and how to fix it.

Scope

The error path only. No API, no payload, no format change. The dsl-debugging probes, records and UI are untouched; their line numbers come from parse-time ANTLR/SnakeYAML tokens baked in as int literals, which never involved bytecode. Verified: getStackTrace|StackTraceElement has 0 hits across oap-server, apm-protocol, apm-webapp — no production code reads a stack frame, which is also why this survived so long.

Known gaps

• Hierarchy and OAL's metrics-builder write no sidecar, so their SourceFile still addresses nothing. Adding a writer is a feature, not a fix; recorded rather than half-fixed.
• LAL and OAL frames resolve to a file but carry no line, pending the single-entry follow-up.
• Zabbix loads its YAML without stamping, so its rules get _Lunknown_ names. The variant it needs (MalYamlLineIndex.index(yaml, "metrics")) exists and is unit-tested; only the loader wiring is missing.

Testing

The stack frame's three coordinates each have a dedicated test: classNameCarriesTheRealYamlLine (the _L37_ segment on a real compiled rule), sourceFileNamesTheFileThatWasActuallyWritten, and everyLineNumberEntryPointsAtAStatementInThatFile / theLastBoundaryIsTheReturn.

Line-number fixtures are test-only DSL, in both MAL and LAL. Shipped rules were read to learn the shape worth mimicking — a tag({...}) closure in expPrefix/expSuffix is the majority pattern — but are never used as fixtures, so a rule edit cannot break a line assertion.

Every behaviour fails without its fix:

mutation	failure
drop the companion sidecar	no companion sidecar carries the expPrefix closure body
COMPANION_SAM_LINE_IN_CLASS 9 → 10	line 10 should hold the SAM signature but was: 'java.util.Map tags = ...'
restore the LAL provenance format	expected: <..._2.java> but was: <(execution-basic.yaml:304)..._2.java>
restore LAL's ordinal table	found 4 entries, first pointing at line 1
drop > 0 normalisation in MalSourceRef.of	expected: <-1> but was: <0>
shift COMPANION_SAM_LINE_IN_CLASS	lands on the cast, not the signature

Pre-flight: CHECKSTYLE_EXIT=0 LICENSE_EXIT=0 TESTS_EXIT=0 BUILD_EXIT=0; license 0 invalid of 4983; 0 javadoc error: lines; 0 failing suites (MAL 1403, LAL 214, OAL 98).

• Update the CHANGES log.

[Copilot]

Pull request overview

Fixes MAL operator-facing YAML attribution and generated Java debug coordinates.

Changes:

• Adds YAML source indexing and per-stage debug line propagation.
• Aligns generated SourceFile and LineNumberTable metadata.
• Adds tests, documentation, and changelog updates.

Reviewed changes

Copilot reviewed 34 out of 34 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
MalFileApplier.java	Stamps runtime-rule source lines.
MALDebugRecorderImpl.java	Records probe source lines.
MalYamlLineIndexTest.java	Tests YAML anchor indexing.
MalProbeSourceLineTest.java	Tests per-stage attribution.
MalSourceMapTest.java	Tests expression source mapping.
MalProbeEmissionTest.java	Tests emitted probe literals.
MalPrefixInjectionRangesTest.java	Tests prefix splice ranges.
MalLineAttributionTest.java	Validates generated class metadata.
MalGeneratedSourceLinesTest.java	Tests statement-line detection.
RuleSourceLines.java	Applies source anchors to rules.
Rules.java	Indexes disk-loaded rule text.
Rule.java	Stores file-level anchors.
MetricsRule.java	Stores per-rule anchors.
MetricRuleConfig.java	Exposes source-line contracts.
MetricConvert.java	Builds and propagates source maps.
MalYamlLineIndex.java	Resolves YAML node lines.
MALDebugRecorder.java	Adds source-line parameters.
MALDebug.java	Forwards probe source lines.
DSL.java	Adds source-mapped parsing.
MalSourceRef.java	Models YAML/generated coordinates.
MalSourceMap.java	Maps expression offsets to YAML.
MALScriptParser.java	Tracks prefix and method offsets.
MALMethodChainCodegen.java	Attributes chain-stage probes.
MalGeneratedSourceLines.java	Finds generated statement lines.
MALExpressionModel.java	Stores method-call source offsets.
MALExprCodegen.java	Emits attributed probes.
MALCodegenHelper.java	Adds line literals to probes.
MALClosureCodegen.java	Removes misleading companion tables.
MALClassGenerator.java	Aligns generated source metadata.
MALBytecodeHelper.java	Builds generated-source line tables.
Analyzer.java	Attributes filter/output probes.
dsl-debugging-mal.md	Documents MAL sourceLine.
dynamic-code-generation-debugging.md	Documents coordinate spaces.
changes.md	Records the attribution fix.

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