wasm gc: support source maps

core/src/main/java/org/teavm/backend/wasm/WasmGCTarget.java

@@ -22,9 +22,11 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
+import org.teavm.backend.wasm.debug.CompositeDebugLines;
 import org.teavm.backend.wasm.debug.DebugLines;
 import org.teavm.backend.wasm.debug.ExternalDebugFile;
 import org.teavm.backend.wasm.debug.GCDebugInfoBuilder;
+import org.teavm.backend.wasm.debug.sourcemap.SourceMapBuilder;
 import org.teavm.backend.wasm.gc.TeaVMWasmGCHost;
 import org.teavm.backend.wasm.gc.WasmGCClassConsumer;
 import org.teavm.backend.wasm.gc.WasmGCClassConsumerContext;
@@ -40,6 +42,7 @@ import org.teavm.backend.wasm.generators.gc.WasmGCCustomGenerators;
 import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsic;
 import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicFactory;
 import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsics;
+import org.teavm.backend.wasm.model.WasmCustomSection;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.backend.wasm.model.WasmTag;
@@ -77,6 +80,8 @@ public class WasmGCTarget implements TeaVMTarget, TeaVMWasmGCHost {
     private boolean strict;
     private boolean obfuscated;
     private boolean debugInfo;
+    private SourceMapBuilder sourceMapBuilder;
+    private String sourceMapLocation;
     private WasmDebugInfoLocation debugLocation = WasmDebugInfoLocation.EXTERNAL;
     private WasmDebugInfoLevel debugLevel = WasmDebugInfoLevel.FULL;
     private List<WasmGCIntrinsicFactory> intrinsicFactories = new ArrayList<>();
@@ -107,6 +112,14 @@ public class WasmGCTarget implements TeaVMTarget, TeaVMWasmGCHost {
         this.debugLocation = debugLocation;
     }
 
+    public void setSourceMapBuilder(SourceMapBuilder sourceMapBuilder) {
+        this.sourceMapBuilder = sourceMapBuilder;
+    }
+
+    public void setSourceMapLocation(String sourceMapLocation) {
+        this.sourceMapLocation = sourceMapLocation;
+    }
+
     @Override
     public void addIntrinsicFactory(WasmGCIntrinsicFactory intrinsicFactory) {
         intrinsicFactories.add(intrinsicFactory);
@@ -337,7 +350,22 @@ public class WasmGCTarget implements TeaVMTarget, TeaVMWasmGCHost {
         var binaryWriter = new WasmBinaryWriter();
         DebugLines debugLines = null;
         if (debugInfo) {
-            debugLines = debugInfoBuilder.lines();
+            if (sourceMapBuilder != null) {
+                debugLines = new CompositeDebugLines(debugInfoBuilder.lines(), sourceMapBuilder);
+            } else {
+                debugLines = debugInfoBuilder.lines();
+            }
+        } else if (sourceMapBuilder != null) {
+            debugLines = sourceMapBuilder;
+        }
+        if (!outputName.endsWith(".wasm")) {
+            outputName += ".wasm";
+        }
+        if (sourceMapBuilder != null && sourceMapLocation != null) {
+            var sourceMapBinding = new WasmBinaryWriter();
+            sourceMapBinding.writeAsciiString(sourceMapLocation);
+            var sourceMapSection = new WasmCustomSection("sourceMappingURL", sourceMapBinding.getData());
+            module.add(sourceMapSection);
         }
         var binaryRenderer = new WasmBinaryRenderer(binaryWriter, WasmBinaryVersion.V_0x1, obfuscated,
                 null, null, debugLines, null, WasmBinaryStatsCollector.EMPTY);
@@ -349,9 +377,6 @@ public class WasmGCTarget implements TeaVMTarget, TeaVMWasmGCHost {
             binaryRenderer.render(module);
         }
         var data = binaryWriter.getData();
-        if (!outputName.endsWith(".wasm")) {
-            outputName += ".wasm";
-        }
         try (var output = buildTarget.createResource(outputName)) {
             output.write(data);
         }

core/src/main/java/org/teavm/backend/wasm/debug/CompositeDebugLines.java

@@ -0,0 +1,59 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.debug;
+
+import org.teavm.backend.wasm.debug.sourcemap.SourceMapBuilder;
+import org.teavm.model.MethodReference;
+
+public class CompositeDebugLines implements DebugLines {
+    private DebugLines debugLinesBuilder;
+    private SourceMapBuilder sourceMapBuilder;
+
+    public CompositeDebugLines(DebugLines debugLinesBuilder, SourceMapBuilder sourceMapBuilder) {
+        this.debugLinesBuilder = debugLinesBuilder;
+        this.sourceMapBuilder = sourceMapBuilder;
+    }
+
+    @Override
+    public void advance(int ptr) {
+        debugLinesBuilder.advance(ptr);
+        sourceMapBuilder.advance(ptr);
+    }
+
+    @Override
+    public void location(String file, int line) {
+        debugLinesBuilder.location(file, line);
+        sourceMapBuilder.location(file, line);
+    }
+
+    @Override
+    public void emptyLocation() {
+        debugLinesBuilder.emptyLocation();
+        sourceMapBuilder.emptyLocation();
+    }
+
+    @Override
+    public void start(MethodReference methodReference) {
+        debugLinesBuilder.start(methodReference);
+        sourceMapBuilder.start(methodReference);
+    }
+
+    @Override
+    public void end() {
+        debugLinesBuilder.end();
+        sourceMapBuilder.end();
+    }
+}

core/src/main/java/org/teavm/backend/wasm/debug/sourcemap/SourceMapBuilder.java

@@ -0,0 +1,205 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.debug.sourcemap;
+
+import com.carrotsearch.hppc.ObjectIntHashMap;
+import com.carrotsearch.hppc.ObjectIntMap;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.List;
+import java.util.Objects;
+import org.teavm.backend.wasm.debug.DebugLines;
+import org.teavm.common.JsonUtil;
+import org.teavm.debugging.information.SourceFileResolver;
+import org.teavm.model.MethodReference;
+
+public class SourceMapBuilder implements DebugLines {
+    private static final String BASE64_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+    private List<String> fileNames = new ArrayList<>();
+    private ObjectIntMap<String> fileNameIndexes = new ObjectIntHashMap<>();
+    private int ptr;
+    private StringBuilder mappings = new StringBuilder();
+    private String currentFile;
+    private int currentLine;
+    private String lastWrittenFile;
+    private int lastWrittenLine;
+    private boolean pendingLocation;
+    private Deque<InlineState> inlineStack = new ArrayDeque<>();
+    private List<SourceFileResolver> sourceFileResolvers = new ArrayList<>();
+
+    private String lastFileInMappings;
+    private int lastLineInMappings;
+    private int lastPtrInMappings;
+
+    public void addSourceResolver(SourceFileResolver sourceFileResolver) {
+        sourceFileResolvers.add(sourceFileResolver);
+    }
+
+    public void writeSourceMap(Writer output) throws IOException {
+        output.write("{\"version\":3");
+
+        var files = resolveFiles();
+        if (!files.isEmpty()) {
+            var commonPrefix = files.get(0);
+            var commonPrefixLength = commonPrefix.length();
+            for (var i = 1; i < files.size(); ++i) {
+                var file = files.get(i);
+                commonPrefixLength = Math.min(file.length(), commonPrefixLength);
+                for (var j = 0; j < commonPrefixLength; ++j) {
+                    if (commonPrefix.charAt(j) != file.charAt(j)) {
+                        commonPrefixLength = j;
+                        break;
+                    }
+                }
+                if (commonPrefixLength == 0) {
+                    break;
+                }
+            }
+            if (commonPrefixLength > 0) {
+                for (var i = 0; i < files.size(); ++i) {
+                    files.set(i, files.get(i).substring(commonPrefixLength));
+                }
+                output.write(",\"sourceRoot\":\"");
+                JsonUtil.writeEscapedString(output, commonPrefix.substring(0, commonPrefixLength));
+                output.write("\"");
+            }
+        }
+        output.write(",\"sources\":[");
+        for (int i = 0; i < files.size(); ++i) {
+            if (i > 0) {
+                output.write(',');
+            }
+            output.write("\"");
+            var name = files.get(i);
+            JsonUtil.writeEscapedString(output, name);
+            output.write("\"");
+        }
+        output.write("]");
+        output.write(",\"names\":[]");
+        output.write(",\"mappings\":\"");
+        output.write(mappings.toString());
+        output.write("\"}");
+    }
+
+    private List<String> resolveFiles() throws IOException {
+        var result = new ArrayList<String>();
+        for (var file : fileNames) {
+            var resolvedFile = file;
+            for (var resolver : sourceFileResolvers) {
+                var candidate = resolver.resolveFile(file);
+                if (candidate != null) {
+                    resolvedFile = candidate;
+                    break;
+                }
+            }
+            result.add(resolvedFile);
+        }
+        return result;
+    }
+
+    @Override
+    public void advance(int ptr) {
+        if (ptr != this.ptr) {
+            if (pendingLocation) {
+                pendingLocation = false;
+                if (!Objects.equals(currentFile, lastWrittenFile) || currentLine != lastWrittenLine) {
+                    lastWrittenFile = currentFile;
+                    lastWrittenLine = currentLine;
+                    writeMapping(currentFile, currentLine, this.ptr);
+                }
+            }
+            this.ptr = ptr;
+        }
+    }
+
+    @Override
+    public void location(String file, int line) {
+        currentFile = file;
+        currentLine = line;
+        pendingLocation = true;
+    }
+
+    @Override
+    public void emptyLocation() {
+        currentLine = -1;
+        currentFile = null;
+        pendingLocation = false;
+    }
+
+    @Override
+    public void start(MethodReference methodReference) {
+        inlineStack.push(new InlineState(currentFile, currentLine));
+    }
+
+    @Override
+    public void end() {
+        var state = inlineStack.pop();
+        location(state.file, state.line);
+    }
+
+    private void writeMapping(String file, int line, int ptr) {
+        if (mappings.length() > 0) {
+            mappings.append(",");
+        }
+        writeVLQ(ptr - lastPtrInMappings);
+        if (file != null && line > 0) {
+            --line;
+            var lastFileIndex = fileNameIndexes.get(lastFileInMappings);
+            var fileIndex = fileNameIndexes.getOrDefault(file, -1);
+            if (fileIndex < 0) {
+                fileIndex = fileNames.size();
+                fileNames.add(file);
+                fileNameIndexes.put(file, fileIndex);
+            }
+            writeVLQ(fileIndex - lastFileIndex);
+            writeVLQ(line - lastLineInMappings);
+            writeVLQ(0);
+            lastLineInMappings = line;
+            lastFileInMappings = file;
+        }
+        lastPtrInMappings = ptr;
+    }
+
+    private void writeVLQ(int number) {
+        if (number < 0) {
+            number = ((-number) << 1) | 1;
+        } else {
+            number = number << 1;
+        }
+        do {
+            int digit = number & 0x1F;
+            int next = number >>> 5;
+            if (next != 0) {
+                digit |= 0x20;
+            }
+            mappings.append(BASE64_CHARS.charAt(digit));
+            number = next;
+        } while (number != 0);
+    }
+
+    private static class InlineState {
+        String file;
+        int line;
+
+        InlineState(String file, int line) {
+            this.file = file;
+            this.line = line;
+        }
+    }
+}

tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java

@@ -43,6 +43,7 @@ import org.teavm.backend.wasm.WasmDebugInfoLocation;
 import org.teavm.backend.wasm.WasmGCTarget;
 import org.teavm.backend.wasm.WasmRuntimeType;
 import org.teavm.backend.wasm.WasmTarget;
+import org.teavm.backend.wasm.debug.sourcemap.SourceMapBuilder;
 import org.teavm.backend.wasm.render.WasmBinaryVersion;
 import org.teavm.cache.AlwaysStaleCacheStatus;
 import org.teavm.cache.CacheStatus;
@@ -65,6 +66,7 @@ import org.teavm.model.PreOptimizingClassHolderSource;
 import org.teavm.model.ReferenceCache;
 import org.teavm.model.transformation.AssertionRemoval;
 import org.teavm.parsing.ClasspathClassHolderSource;
+import org.teavm.tooling.sources.DefaultSourceFileResolver;
 import org.teavm.tooling.sources.SourceFileProvider;
 import org.teavm.vm.BuildTarget;
 import org.teavm.vm.DirectoryBuildTarget;
@@ -121,6 +123,7 @@ public class TeaVMTool {
     private boolean heapDump;
     private boolean shortFileNames;
     private boolean assertionsRemoved;
+    private SourceMapBuilder wasmSourceMapWriter;
 
     public File getTargetDirectory() {
         return targetDirectory;
@@ -403,6 +406,10 @@ public class TeaVMTool {
         target.setDebugInfo(debugInformationGenerated);
         target.setDebugInfoLevel(debugInformationGenerated ? WasmDebugInfoLevel.FULL : wasmDebugInfoLevel);
         target.setDebugInfoLocation(wasmDebugInfoLocation);
+        if (sourceMapsFileGenerated) {
+            target.setSourceMapBuilder(wasmSourceMapWriter);
+            target.setSourceMapLocation(getResolvedTargetFileName() + ".map");
+        }
         return target;
     }
 
@@ -527,6 +534,8 @@ public class TeaVMTool {
                         Writer writer = new OutputStreamWriter(output, StandardCharsets.UTF_8)) {
                     additionalJavaScriptOutput(writer);
                 }
+            } else if (targetType == TeaVMTargetType.WEBASSEMBLY_GC) {
+                additionalWasmGCOutput();
             }
 
             if (incremental) {
@@ -591,42 +600,39 @@ public class TeaVMTool {
         }
     }
 
+    private void additionalWasmGCOutput() throws IOException {
+        if (sourceMapsFileGenerated) {
+            var targetDir = new File(targetDirectory, "src");
+            var resolver = new DefaultSourceFileResolver(targetDir, sourceFileProviders);
+            resolver.setSourceFilePolicy(sourceFilePolicy);
+            resolver.open();
+
+            if (sourceFilePolicy != TeaVMSourceFilePolicy.DO_NOTHING) {
+                wasmSourceMapWriter.addSourceResolver(resolver);
+            }
+            var file = new File(targetDirectory, getResolvedTargetFileName() + ".map");
+            try (var out = new FileOutputStream(file);
+                    var writer = new OutputStreamWriter(out, StandardCharsets.UTF_8)) {
+                wasmSourceMapWriter.writeSourceMap(writer);
+            }
+
+            resolver.close();
+        }
+    }
+
     private void writeSourceMaps(Writer out, DebugInformation debugInfo) throws IOException {
         var sourceMapWriter = new SourceMapsWriter(out);
-        for (var provider : sourceFileProviders) {
-            provider.open();
-        }
-
         var targetDir = new File(targetDirectory, "src");
+        var resolver = new DefaultSourceFileResolver(targetDir, sourceFileProviders);
+        resolver.setSourceFilePolicy(sourceFilePolicy);
+        resolver.open();
+
         if (sourceFilePolicy != TeaVMSourceFilePolicy.DO_NOTHING) {
-            sourceMapWriter.addSourceResolver(fileName -> {
+            sourceMapWriter.addSourceResolver(resolver);
-                for (var provider : sourceFileProviders) {
-                    var sourceFile = provider.getSourceFile(fileName);
-                    if (sourceFile != null) {
-                        if (sourceFilePolicy == TeaVMSourceFilePolicy.COPY || sourceFile.getFile() == null) {
-                            var outputFile = new File(targetDir, fileName);
-                            outputFile.getParentFile().mkdirs();
-                            try (var input = sourceFile.open();
-                                    var output = new FileOutputStream(outputFile)) {
-                                input.transferTo(output);
-                            }
-                            if (sourceFilePolicy == TeaVMSourceFilePolicy.LINK_LOCAL_FILES) {
-                                return "file://" + outputFile.getCanonicalPath();
-                            }
-                        } else {
-                            return "file://" + sourceFile.getFile().getCanonicalPath();
-                        }
-                        break;
-                    }
-                }
-                return null;
-            });
         }
         sourceMapWriter.write(getResolvedTargetFileName(), "src", debugInfo);
 
-        for (var provider : sourceFileProviders) {
+        resolver.close();
-            provider.close();
-        }
     }
 
     private void printStats() {

tools/core/src/main/java/org/teavm/tooling/sources/DefaultSourceFileResolver.java

@@ -0,0 +1,74 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.tooling.sources;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.List;
+import org.teavm.debugging.information.SourceFileResolver;
+import org.teavm.tooling.TeaVMSourceFilePolicy;
+
+public class DefaultSourceFileResolver implements SourceFileResolver {
+    private File targetDir;
+    private List<SourceFileProvider> sourceFileProviders;
+    private TeaVMSourceFilePolicy sourceFilePolicy = TeaVMSourceFilePolicy.DO_NOTHING;
+
+    public DefaultSourceFileResolver(File targetDir, List<SourceFileProvider> sourceFileProviders) {
+        this.targetDir = targetDir;
+        this.sourceFileProviders = sourceFileProviders;
+    }
+
+    public void setSourceFilePolicy(TeaVMSourceFilePolicy sourceFilePolicy) {
+        this.sourceFilePolicy = sourceFilePolicy;
+    }
+
+    public void open() throws IOException {
+        for (var provider : sourceFileProviders) {
+            provider.open();
+        }
+    }
+
+    @Override
+    public String resolveFile(String file) throws IOException {
+        for (var provider : sourceFileProviders) {
+            var sourceFile = provider.getSourceFile(file);
+            if (sourceFile != null) {
+                if (sourceFilePolicy == TeaVMSourceFilePolicy.COPY || sourceFile.getFile() == null) {
+                    var outputFile = new File(targetDir, file);
+                    outputFile.getParentFile().mkdirs();
+                    try (var input = sourceFile.open();
+                            var output = new FileOutputStream(outputFile)) {
+                        input.transferTo(output);
+                    }
+                    if (sourceFilePolicy == TeaVMSourceFilePolicy.LINK_LOCAL_FILES) {
+                        return "file://" + outputFile.getCanonicalPath();
+                    }
+                } else {
+                    return "file://" + sourceFile.getFile().getCanonicalPath();
+                }
+                break;
+            }
+        }
+        return null;
+    }
+
+    public void close() throws IOException {
+        for (var provider : sourceFileProviders) {
+            provider.close();
+        }
+    }
+}

tools/junit/src/main/java/org/teavm/junit/BaseWebAssemblyPlatformSupport.java

@@ -56,7 +56,7 @@ abstract class BaseWebAssemblyPlatformSupport extends TestPlatformSupport<WasmTa
             if (sourceDirs != null) {
                 var dirs = new ArrayList<File>();
                 for (var tokenizer = new StringTokenizer(sourceDirs, Character.toString(File.pathSeparatorChar));
-                     tokenizer.hasMoreTokens();) {
+                        tokenizer.hasMoreTokens();) {
                     var dir = new File(tokenizer.nextToken());
                     if (dir.isDirectory()) {
                         dirs.add(dir);

tools/junit/src/main/java/org/teavm/junit/TestPlatformSupport.java

@@ -124,16 +124,18 @@ abstract class TestPlatformSupport<T extends TeaVMTarget> {
     }
 
     protected final File getOutputFile(File path, String baseName, String suffix, String extension) {
+        return new File(path, getOutputSimpleNameFile(baseName, suffix, extension));
+    }
+
+
+    protected final String getOutputSimpleNameFile(String baseName, String suffix, String extension) {
         StringBuilder simpleName = new StringBuilder();
         simpleName.append(baseName);
         if (!suffix.isEmpty()) {
             simpleName.append('-').append(suffix);
         }
-        File outputFile;
         simpleName.append(extension);
-        outputFile = new File(path, simpleName.toString());
+        return simpleName.toString();
-
-        return outputFile;
     }
 
     private String buildErrorMessage(TeaVM vm) {

tools/junit/src/main/java/org/teavm/junit/WebAssemblyGCPlatformSupport.java

@@ -15,6 +15,7 @@
  */
 package org.teavm.junit;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.teavm.junit.PropertyNames.OPTIMIZED;
 import static org.teavm.junit.PropertyNames.SOURCE_DIRS;
 import static org.teavm.junit.PropertyNames.WASM_GC_ENABLED;
@@ -35,20 +36,39 @@ import java.util.function.Supplier;
 import org.teavm.backend.wasm.WasmDebugInfoLevel;
 import org.teavm.backend.wasm.WasmDebugInfoLocation;
 import org.teavm.backend.wasm.WasmGCTarget;
+import org.teavm.backend.wasm.debug.sourcemap.SourceMapBuilder;
 import org.teavm.backend.wasm.disasm.Disassembler;
 import org.teavm.backend.wasm.disasm.DisassemblyHTMLWriter;
 import org.teavm.browserrunner.BrowserRunner;
 import org.teavm.model.ClassHolderSource;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ReferenceCache;
+import org.teavm.tooling.TeaVMSourceFilePolicy;
+import org.teavm.tooling.sources.DefaultSourceFileResolver;
+import org.teavm.tooling.sources.DirectorySourceFileProvider;
+import org.teavm.tooling.sources.JarSourceFileProvider;
+import org.teavm.tooling.sources.SourceFileProvider;
 import org.teavm.vm.TeaVM;
 
 class WebAssemblyGCPlatformSupport extends TestPlatformSupport<WasmGCTarget> {
     private boolean disassembly;
+    private List<SourceFileProvider> sourceFileProviders = new ArrayList<>();
 
     WebAssemblyGCPlatformSupport(ClassHolderSource classSource, ReferenceCache referenceCache, boolean disassembly) {
         super(classSource, referenceCache);
         this.disassembly = disassembly;
+        var sourceDirs = System.getProperty(SOURCE_DIRS);
+        if (sourceDirs != null) {
+            for (var tokenizer = new StringTokenizer(sourceDirs, Character.toString(File.pathSeparatorChar));
+                    tokenizer.hasMoreTokens();) {
+                var file = new File(tokenizer.nextToken());
+                if (file.isDirectory()) {
+                    sourceFileProviders.add(new DirectorySourceFileProvider(file));
+                } else if (file.isFile() && file.getName().endsWith(".jar")) {
+                    sourceFileProviders.add(new JarSourceFileProvider(file));
+                }
+            }
+        }
     }
 
     @Override
@@ -67,6 +87,8 @@ class WebAssemblyGCPlatformSupport extends TestPlatformSupport<WasmGCTarget> {
     @Override
     CompileResult compile(Consumer<TeaVM> additionalProcessing, String baseName,
             TeaVMTestConfiguration<WasmGCTarget> configuration, File path, AnnotatedElement element) {
+        var sourceMapBuilder = new SourceMapBuilder();
+        var sourceMapFile = getOutputFile(path, baseName, configuration.getSuffix(), ".wasm.map");
         Supplier<WasmGCTarget> targetSupplier = () -> {
             var target = new WasmGCTarget();
             target.setObfuscated(false);
@@ -74,6 +96,8 @@ class WebAssemblyGCPlatformSupport extends TestPlatformSupport<WasmGCTarget> {
             target.setDebugInfo(true);
             target.setDebugInfoLevel(WasmDebugInfoLevel.DEOBFUSCATION);
             target.setDebugInfoLocation(WasmDebugInfoLocation.EMBEDDED);
+            target.setSourceMapBuilder(sourceMapBuilder);
+            target.setSourceMapLocation(getOutputSimpleNameFile(baseName, configuration.getSuffix(), ".wasm.map"));
             var sourceDirs = System.getProperty(SOURCE_DIRS);
             if (sourceDirs != null) {
                 var dirs = new ArrayList<File>();
@@ -87,8 +111,22 @@ class WebAssemblyGCPlatformSupport extends TestPlatformSupport<WasmGCTarget> {
             }
             return target;
         };
+        CompilePostProcessor postBuild = (vm, file) -> {
+            var resolver = new DefaultSourceFileResolver(new File(path, "src"), sourceFileProviders);
+            resolver.setSourceFilePolicy(TeaVMSourceFilePolicy.LINK_LOCAL_FILES);
+            sourceMapBuilder.addSourceResolver(resolver);
+            try {
+                resolver.open();
+                try (var sourceMapOut = new OutputStreamWriter(new FileOutputStream(sourceMapFile), UTF_8)) {
+                    sourceMapBuilder.writeSourceMap(sourceMapOut);
+                }
+                resolver.close();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        };
         return compile(configuration, targetSupplier, TestWasmGCEntryPoint.class.getName(), path,
-                ".wasm", null, additionalProcessing, baseName);
+                ".wasm", postBuild, additionalProcessing, baseName);
     }
 
     @Override