From cfd381f47bbd2e055495f27766f62dffe3095a56 Mon Sep 17 00:00:00 2001
From: Alexey Andreev <konsoletyper@gmail.com>
Date: Sun, 13 Oct 2024 20:26:37 +0200
Subject: [PATCH] wasm gc: fix bugs in stack trace deobfuscator

---
 .../teavm/backend/wasm/debug/info/LineInfo.java  | 16 +++++++++++-----
 .../backend/wasm/render/WasmBinaryRenderer.java  |  2 ++
 .../wasm/render/WasmBinaryRenderingVisitor.java  |  4 ++++
 .../src/main/resources/test-server/frame.js      |  2 ++
 .../tooling/deobfuscate/wasmgc/Deobfuscator.java |  2 +-
 .../main/resources/teavm-run-test-wasm-gc.html   |  3 ++-
 6 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/core/src/main/java/org/teavm/backend/wasm/debug/info/LineInfo.java b/core/src/main/java/org/teavm/backend/wasm/debug/info/LineInfo.java
index 9363fe597..32dfc38c9 100644
--- a/core/src/main/java/org/teavm/backend/wasm/debug/info/LineInfo.java
+++ b/core/src/main/java/org/teavm/backend/wasm/debug/info/LineInfo.java
@@ -53,18 +53,18 @@ public class LineInfo {
         }
         var instructionLoc = sequence.unpack().find(address);
         if (instructionLoc == null) {
-            return null;
+            return returnForSequence(sequence);
         }
         var location = instructionLoc.location();
         if (location == null) {
-            return null;
+            return returnForSequence(sequence);
         }
         var result = new DeobfuscatedLocation[location.depth()];
         var method = sequence.method();
-        var i = 0;
+        var i = result.length - 1;
         while (true) {
-            result[i++] = new DeobfuscatedLocation(location.file(), method, location.line());
-            if (i >= result.length) {
+            result[i--] = new DeobfuscatedLocation(location.file(), method, location.line());
+            if (i < 0) {
                 break;
             }
             method = location.inlining().method();
@@ -73,6 +73,12 @@ public class LineInfo {
         return result;
     }
 
+    private DeobfuscatedLocation[] returnForSequence(LineInfoSequence sequence) {
+        return new DeobfuscatedLocation[] {
+                new DeobfuscatedLocation(null, sequence.method(), -1)
+        };
+    }
+
     public LineInfoSequence find(int address) {
         var index = CollectionUtil.binarySearch(sequenceList, address, LineInfoSequence::endAddress);
         if (index < 0) {
diff --git a/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderer.java b/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderer.java
index 35be5415f..a91e99ee8 100644
--- a/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderer.java
+++ b/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderer.java
@@ -364,6 +364,7 @@ public class WasmBinaryRenderer {
             dwarfSubprogram.function = function;
         }
         if (debugLines != null && function.getJavaMethod() != null) {
+            debugLines.advance(offset + sectionOffset);
             debugLines.start(function.getJavaMethod());
         }
 
@@ -398,6 +399,7 @@ public class WasmBinaryRenderer {
         for (var part : function.getBody()) {
             visitor.preprocess(part);
         }
+        visitor.setPositionToEmit(code.getPosition());
         for (var part : function.getBody()) {
             part.acceptVisitor(visitor);
         }
diff --git a/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderingVisitor.java b/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderingVisitor.java
index 302789f1a..c53a0d2b9 100644
--- a/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderingVisitor.java
+++ b/core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderingVisitor.java
@@ -118,6 +118,10 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         this.debugLines = debugLines;
     }
 
+    public void setPositionToEmit(int positionToEmit) {
+        this.positionToEmit = positionToEmit;
+    }
+
     void preprocess(WasmExpression expression) {
         expression.acceptVisitor(new WasmDefaultExpressionVisitor() {
             @Override
diff --git a/tools/browser-runner/src/main/resources/test-server/frame.js b/tools/browser-runner/src/main/resources/test-server/frame.js
index 59dcd007f..0c77947da 100644
--- a/tools/browser-runner/src/main/resources/test-server/frame.js
+++ b/tools/browser-runner/src/main/resources/test-server/frame.js
@@ -16,6 +16,8 @@
 
 "use strict";
 
+Error.stackTraceLimit = 250;
+
 window.addEventListener("message", event => {
     let request = event.data;
     switch (request.type) {
diff --git a/tools/deobfuscator-wasm-gc/src/main/java/org/teavm/tooling/deobfuscate/wasmgc/Deobfuscator.java b/tools/deobfuscator-wasm-gc/src/main/java/org/teavm/tooling/deobfuscate/wasmgc/Deobfuscator.java
index 7f1a6e12f..5a4f051c6 100644
--- a/tools/deobfuscator-wasm-gc/src/main/java/org/teavm/tooling/deobfuscate/wasmgc/Deobfuscator.java
+++ b/tools/deobfuscator-wasm-gc/src/main/java/org/teavm/tooling/deobfuscate/wasmgc/Deobfuscator.java
@@ -33,7 +33,7 @@ public final class Deobfuscator {
         var frames = new JSArray<Frame>();
         for (var location : locations) {
             var frame = new Frame(location.method.cls().fullName(), location.method.name(),
-                    location.file != null ? location.file.fullName() : null, location.line);
+                    location.file != null ? location.file.name() : null, location.line);
             frames.push(frame);
         }
         return frames;
diff --git a/tools/junit/src/main/resources/teavm-run-test-wasm-gc.html b/tools/junit/src/main/resources/teavm-run-test-wasm-gc.html
index 7eb2e9072..747934e10 100644
--- a/tools/junit/src/main/resources/teavm-run-test-wasm-gc.html
+++ b/tools/junit/src/main/resources/teavm-run-test-wasm-gc.html
@@ -24,6 +24,7 @@
     <script type="text/javascript" src="${SCRIPT}-runtime.js"></script>
     <script type="text/javascript">
         let instance;
+        Error.stackTraceLimit = 250;
         TeaVM.wasmGC.load("${SCRIPT}", {
             stackDeobfuscator: {
                 enabled: true
@@ -31,7 +32,7 @@
             installImports(o) {
                 o.teavmTest = {
                     success() {
-                        var pre = document.createElement("pre");
+                        let pre = document.createElement("pre");
                         document.body.appendChild(pre);
                         pre.appendChild(document.createTextNode("OK"));
                     },