Generate relative paths in JS source maps

Also, add CLI options to manipulate prefixes of path

See KT-4078

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSCompilerArguments.java

@@ -41,6 +41,18 @@ public class K2JSCompilerArguments extends CommonCompilerArguments {
     @Argument(value = "-source-map", description = "Generate source map")
     public boolean sourceMap;
 
+    @GradleOption(DefaultValues.StringNullDefault.class)
+    @Argument(value = "-source-map-prefix", description = "Prefix for paths in a source map")
+    public String sourceMapPrefix;
+
+    @GradleOption(DefaultValues.StringNullDefault.class)
+    @Argument(
+            value = "-source-map-source-roots",
+            valueDescription = "<path>",
+            description = "Base directories which are used to calculate relative paths to source files in source map"
+    )
+    public String sourceMapSourceRoots;
+
     @GradleOption(DefaultValues.BooleanTrueDefault.class)
     @Argument(value = "-meta-info", description = "Generate .meta.js and .kjsm files with metadata. Use to create a library")
     public boolean metaInfo;

compiler/cli/src/org/jetbrains/kotlin/cli/js/K2JSCompiler.java

@@ -19,7 +19,9 @@ package org.jetbrains.kotlin.cli.js;
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.io.FileUtil;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.util.ExceptionUtil;
 import com.intellij.util.SmartList;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.HashMap;
@@ -34,6 +36,7 @@ import org.jetbrains.kotlin.cli.common.ExitCode;
 import org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments;
 import org.jetbrains.kotlin.cli.common.arguments.K2JsArgumentConstants;
 import org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport;
+import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity;
 import org.jetbrains.kotlin.cli.common.messages.MessageCollector;
 import org.jetbrains.kotlin.cli.common.output.outputUtils.OutputUtilsKt;
 import org.jetbrains.kotlin.cli.jvm.compiler.EnvironmentConfigFiles;
@@ -58,8 +61,8 @@ import org.jetbrains.kotlin.utils.PathUtil;
 import org.jetbrains.kotlin.utils.StringsKt;
 
 import java.io.File;
-import java.util.List;
+import java.io.IOException;
-import java.util.Map;
+import java.util.*;
 
 import static org.jetbrains.kotlin.cli.common.ExitCode.COMPILATION_ERROR;
 import static org.jetbrains.kotlin.cli.common.ExitCode.OK;
@@ -261,6 +264,23 @@ public class K2JSCompiler extends CLICompiler<K2JSCompilerArguments> {
 
         if (arguments.sourceMap) {
             configuration.put(JSConfigurationKeys.SOURCE_MAP, true);
+            if (arguments.sourceMapPrefix != null) {
+                configuration.put(JSConfigurationKeys.SOURCE_MAP_PREFIX, arguments.sourceMapPrefix);
+            }
+
+            String sourceMapSourceRoots = arguments.sourceMapSourceRoots != null ?
+                                          arguments.sourceMapSourceRoots :
+                                          calculateSourceMapSourceRoot(messageCollector, arguments);
+            List<String> sourceMapSourceRootList = StringUtil.split(sourceMapSourceRoots, File.pathSeparator);
+            configuration.put(JSConfigurationKeys.SOURCE_MAP_SOURCE_ROOTS, sourceMapSourceRootList);
+        }
+        else {
+            if (arguments.sourceMapPrefix != null) {
+                messageCollector.report(WARNING, "source-map-prefix argument has no effect without source map", null);
+            }
+            if (arguments.sourceMapSourceRoots != null) {
+                messageCollector.report(WARNING, "source-map-source-root argument has no effect without source map", null);
+            }
         }
         if (arguments.metaInfo) {
             configuration.put(JSConfigurationKeys.META_INFO, true);
@@ -299,6 +319,58 @@ public class K2JSCompiler extends CLICompiler<K2JSCompilerArguments> {
         configuration.put(JSConfigurationKeys.MODULE_KIND, moduleKind);
     }
 
+    @NotNull
+    private static String calculateSourceMapSourceRoot(
+            @NotNull MessageCollector messageCollector,
+            @NotNull K2JSCompilerArguments arguments
+    ) {
+        File commonPath = null;
+        List<File> pathToRoot = new ArrayList<>();
+        Map<File, Integer> pathToRootIndexes = new HashMap<>();
+
+        try {
+            for (String path : arguments.freeArgs) {
+                File file = new File(path).getCanonicalFile();
+                if (commonPath == null) {
+                    commonPath = file;
+
+                    while (file != null) {
+                        pathToRoot.add(file);
+                        file = file.getParentFile();
+                    }
+                    Collections.reverse(pathToRoot);
+
+                    for (int i = 0; i < pathToRoot.size(); ++i) {
+                        pathToRootIndexes.put(pathToRoot.get(i), i);
+                    }
+                }
+                else {
+                    while (file != null) {
+                        Integer existingIndex = pathToRootIndexes.get(file);
+                        if (existingIndex != null) {
+                            existingIndex = Math.min(existingIndex, pathToRoot.size() - 1);
+                            pathToRoot.subList(existingIndex + 1, pathToRoot.size()).clear();
+                            commonPath = pathToRoot.get(pathToRoot.size() - 1);
+                            break;
+                        }
+                        file = file.getParentFile();
+                    }
+                    if (file == null) {
+                        break;
+                    }
+                }
+            }
+        }
+        catch (IOException e) {
+            String text = ExceptionUtil.getThrowableText(e);
+            messageCollector.report(CompilerMessageSeverity.ERROR, "IO error occurred calculating source root:\n" + text, null);
+            return ".";
+        }
+
+        return commonPath != null ? commonPath.getPath() : ".";
+    }
+
+
     private static MainCallParameters createMainCallParameters(String main) {
         if (K2JsArgumentConstants.NO_CALL.equals(main)) {
             return MainCallParameters.noCall();

compiler/testData/cli/js/jsHelp.out

@@ -4,6 +4,9 @@ where possible options include:
   -no-stdlib                 Don't use bundled Kotlin stdlib
   -libraries <path>          Paths to Kotlin libraries with .meta.js and .kjsm files, separated by system path separator
   -source-map                Generate source map
+  -source-map-prefix         Prefix for paths in a source map
+  -source-map-source-roots <path>
+                             Base directories which are used to calculate relative paths to source files in source map
   -meta-info                 Generate .meta.js and .kjsm files with metadata. Use to create a library
   -target { v5 }             Generate JS files for specific ECMA version
   -module-kind { plain, amd, commonjs, umd }

compiler/testData/cli/js/sourceMap.args

@@ -0,0 +1,5 @@
+$TESTDATA_DIR$/sourceMap.kt
+-no-stdlib
+-source-map
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMap.kt

@@ -0,0 +1,5 @@
+var log = ""
+
+fun foo(x: String) {
+    log += "$x;"
+}

compiler/testData/cli/js/sourceMap.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMap.test

@@ -0,0 +1,2 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "sourceMap.kt"

compiler/testData/cli/js/sourceMapPrefix.args

@@ -0,0 +1,7 @@
+$TESTDATA_DIR$/sourceMap.kt
+-no-stdlib
+-source-map
+-source-map-prefix
+http://localhost:8080/src/
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMapPrefix.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMapPrefix.test

@@ -0,0 +1,2 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "http://localhost:8080/src/sourceMap.kt"

compiler/testData/cli/js/sourceMapRoot/bar/baz/file3.kt

@@ -0,0 +1,3 @@
+fun h(): Long {
+    return 42L
+}

compiler/testData/cli/js/sourceMapRoot/bar/file2.kt

@@ -0,0 +1,3 @@
+fun g(): Int {
+    return 23
+}

compiler/testData/cli/js/sourceMapRoot/foo/baz/file4.kt

@@ -0,0 +1,3 @@
+fun j(): Float {
+    return 3.14159f
+}

compiler/testData/cli/js/sourceMapRoot/foo/file1.kt

@@ -0,0 +1,3 @@
+fun f(): String {
+    return "f()"
+}

compiler/testData/cli/js/sourceMapRootAuto.args

@@ -0,0 +1,6 @@
+$TESTDATA_DIR$/sourceMapRoot/foo/file1.kt
+$TESTDATA_DIR$/sourceMapRoot/bar/file2.kt
+-no-stdlib
+-source-map
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMapRootAuto.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMapRootAuto.test

@@ -0,0 +1,3 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "foo/file1.kt"
+// CONTAINS: out.js.map, "bar/file2.kt"

compiler/testData/cli/js/sourceMapRootManual.args

@@ -0,0 +1,8 @@
+$TESTDATA_DIR$/sourceMapRoot/foo/file1.kt
+$TESTDATA_DIR$/sourceMapRoot/bar/file2.kt
+-no-stdlib
+-source-map
+-source-map-source-roots
+$TESTDATA_DIR$/
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMapRootManual.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMapRootManual.test

@@ -0,0 +1,3 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "sourceMapRoot/foo/file1.kt"
+// CONTAINS: out.js.map, "sourceMapRoot/bar/file2.kt"

compiler/testData/cli/js/sourceMapRootMissing.args

@@ -0,0 +1,10 @@
+$TESTDATA_DIR$/sourceMapRoot/foo/file1.kt
+$TESTDATA_DIR$/sourceMapRoot/bar/file2.kt
+$TESTDATA_DIR$/sourceMapRoot/bar/baz/file3.kt
+$TESTDATA_DIR$/sourceMapRoot/foo/baz/file4.kt
+-no-stdlib
+-source-map
+-source-map-source-roots
+$TESTDATA_DIR$/sourceMapRoot/foo
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMapRootMissing.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMapRootMissing.test

@@ -0,0 +1,5 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "file1.kt"
+// CONTAINS: out.js.map, "baz/file4.kt"
+// CONTAINS: out.js.map, "file2.kt"
+// CONTAINS: out.js.map, "file3.kt"

compiler/testData/cli/js/sourceMapRootMultiple.args

@@ -0,0 +1,8 @@
+$TESTDATA_DIR$/sourceMapRoot/foo/file1.kt
+$TESTDATA_DIR$/sourceMapRoot/bar/file2.kt
+-no-stdlib
+-source-map
+-source-map-source-roots
+$TESTDATA_DIR$/foo:$TESTDATA_DIR$/bar
+-output
+$TEMP_DIR$/out.js

compiler/testData/cli/js/sourceMapRootMultiple.out

@@ -0,0 +1 @@
+OK

compiler/testData/cli/js/sourceMapRootMultiple.test

@@ -0,0 +1,3 @@
+// EXISTS: out.js
+// CONTAINS: out.js.map, "file1.kt"
+// CONTAINS: out.js.map, "file2.kt"

compiler/tests/org/jetbrains/kotlin/cli/AbstractCliTest.java

@@ -24,7 +24,6 @@ import kotlin.collections.CollectionsKt;
 import kotlin.io.FilesKt;
 import kotlin.text.Charsets;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.cli.common.CLICompiler;
 import org.jetbrains.kotlin.cli.common.CLITool;
 import org.jetbrains.kotlin.cli.common.ExitCode;
 import org.jetbrains.kotlin.cli.js.K2JSCompiler;
@@ -120,6 +119,26 @@ public abstract class AbstractCliTest extends TestCaseWithTmpdir {
             }
         }
 
+        List<String> containsTextList = InTextDirectivesUtils.findLinesWithPrefixesRemoved(content, "// CONTAINS: ");
+        for (String containsSpec : containsTextList) {
+            String[] parts = containsSpec.split(",", 2);
+            String fileName = parts[0].trim();
+            String contentToSearch = parts[1].trim();
+            File file = new File(tmpdir, fileName);
+            if (!file.exists()) {
+                diagnostics.add("File does not exist: " + fileName);
+            }
+            else if (file.isDirectory()) {
+                diagnostics.add("File is a directory: " + fileName);
+            }
+            else {
+                String text = FilesKt.readText(file, Charsets.UTF_8);
+                if (!text.contains(contentToSearch)) {
+                    diagnostics.add("File " + fileName + " does not contain string: " + contentToSearch);
+                }
+            }
+        }
+
         if (!diagnostics.isEmpty()) {
             diagnostics.add(0, diagnostics.size() + " problem(s) found:");
             Assert.fail(StringsKt.join(diagnostics, "\n"));
@@ -127,7 +146,7 @@ public abstract class AbstractCliTest extends TestCaseWithTmpdir {
     }
 
     @NotNull
-    static List<String> readArgs(@NotNull String argsFilePath, @NotNull String tempDir) throws IOException {
+    private static List<String> readArgs(@NotNull String argsFilePath, @NotNull String tempDir) throws IOException {
         List<String> lines = FilesKt.readLines(new File(argsFilePath), Charsets.UTF_8);
 
         return CollectionsKt.mapNotNull(lines, arg -> {

compiler/tests/org/jetbrains/kotlin/cli/CliTestGenerated.java

@@ -515,6 +515,42 @@ public class CliTestGenerated extends AbstractCliTest {
             doJsTest(fileName);
         }
 
+        @TestMetadata("sourceMap.args")
+        public void testSourceMap() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMap.args");
+            doJsTest(fileName);
+        }
+
+        @TestMetadata("sourceMapPrefix.args")
+        public void testSourceMapPrefix() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMapPrefix.args");
+            doJsTest(fileName);
+        }
+
+        @TestMetadata("sourceMapRootAuto.args")
+        public void testSourceMapRootAuto() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMapRootAuto.args");
+            doJsTest(fileName);
+        }
+
+        @TestMetadata("sourceMapRootManual.args")
+        public void testSourceMapRootManual() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMapRootManual.args");
+            doJsTest(fileName);
+        }
+
+        @TestMetadata("sourceMapRootMissing.args")
+        public void testSourceMapRootMissing() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMapRootMissing.args");
+            doJsTest(fileName);
+        }
+
+        @TestMetadata("sourceMapRootMultiple.args")
+        public void testSourceMapRootMultiple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/sourceMapRootMultiple.args");
+            doJsTest(fileName);
+        }
+
         @TestMetadata("suppressAllWarningsJS.args")
         public void testSuppressAllWarningsJS() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/js/suppressAllWarningsJS.args");

js/js.frontend/src/org/jetbrains/kotlin/js/config/JSConfigurationKeys.java

@@ -29,6 +29,12 @@ public class JSConfigurationKeys {
     public static final CompilerConfigurationKey<Boolean> SOURCE_MAP =
             CompilerConfigurationKey.create("generate source map");
 
+    public static final CompilerConfigurationKey<String> SOURCE_MAP_PREFIX =
+            CompilerConfigurationKey.create("prefix to add to paths in source map");
+
+    public static final CompilerConfigurationKey<List<String>> SOURCE_MAP_SOURCE_ROOTS =
+            CompilerConfigurationKey.create("base directories used to calculate relative paths for source map");
+
     public static final CompilerConfigurationKey<Boolean> META_INFO =
             CompilerConfigurationKey.create("generate .meta.js and .kjsm files");
 

js/js.frontend/src/org/jetbrains/kotlin/js/config/JsConfig.java

@@ -103,6 +103,16 @@ public class JsConfig {
         return getConfiguration().getList(JSConfigurationKeys.LIBRARIES);
     }
 
+    @NotNull
+    public String getSourceMapPrefix() {
+        return configuration.get(JSConfigurationKeys.SOURCE_MAP_PREFIX, "");
+    }
+
+    @NotNull
+    public List<String> getSourceMapRoots() {
+        return configuration.get(JSConfigurationKeys.SOURCE_MAP_SOURCE_ROOTS, Collections.singletonList("."));
+    }
+
     @NotNull
     public List<String> getFriends() {
         if (getConfiguration().getBoolean(JSConfigurationKeys.FRIEND_PATHS_DISABLED)) return Collections.emptyList();

js/js.serializer/src/org/jetbrains/kotlin/serialization/js/ast/JsAstSerializer.kt

@@ -22,11 +22,12 @@ import org.jetbrains.kotlin.js.backend.ast.metadata.*
 import org.jetbrains.kotlin.serialization.js.ast.JsAstProtoBuf.*
 import org.jetbrains.kotlin.serialization.js.ast.JsAstProtoBuf.BinaryOperation.Type.*
 import org.jetbrains.kotlin.serialization.js.ast.JsAstProtoBuf.UnaryOperation.Type.*
+import java.io.File
 import java.io.OutputStream
 import java.util.*
 import org.jetbrains.kotlin.resolve.inline.InlineStrategy as KotlinInlineStrategy
 
-class JsAstSerializer {
+class JsAstSerializer(private val pathResolver: (File) -> String) {
     private val nameTableBuilder = NameTable.newBuilder()
     private val stringTableBuilder = StringTable.newBuilder()
     private val nameMap = mutableMapOf<JsName, Int>()
@@ -567,9 +568,9 @@ class JsAstSerializer {
         if (location != null) {
             val lastFile = fileStack.peek()
             val newFile = location.file
-            fileChanged = lastFile != newFile && newFile != null
+            fileChanged = lastFile != newFile
             if (fileChanged) {
-                fileConsumer(serialize(newFile!!))
+                fileConsumer(serialize(newFile))
                 fileStack.push(location.file)
             }
             val locationBuilder = Location.newBuilder()
@@ -598,7 +599,7 @@ class JsAstSerializer {
         val file = element.containingFile
         val document = file.viewProvider.document!!
 
-        val path = file.viewProvider.virtualFile.path
+        val path = pathResolver(File(file.viewProvider.virtualFile.path))
 
         val startOffset = element.node.startOffset
         val startLine = document.getLineNumber(startOffset)

js/js.tests/test/org/jetbrains/kotlin/js/test/BasicBoxTest.kt

@@ -42,6 +42,7 @@ import org.jetbrains.kotlin.js.facade.*
 import org.jetbrains.kotlin.js.parser.parse
 import org.jetbrains.kotlin.js.parser.sourcemaps.*
 import org.jetbrains.kotlin.js.sourceMap.JsSourceGenerationVisitor
+import org.jetbrains.kotlin.js.sourceMap.SourceFilePathResolver
 import org.jetbrains.kotlin.js.sourceMap.SourceMap3Builder
 import org.jetbrains.kotlin.js.test.utils.*
 import org.jetbrains.kotlin.js.util.TextOutputImpl
@@ -409,7 +410,8 @@ abstract class BasicBoxTest(
         generatedProgram.accept(AmbiguousAstSourcePropagation())
 
         val output = TextOutputImpl()
-        val sourceMapBuilder = SourceMap3Builder(outputFile, output, SourceMapBuilderConsumer())
+        val pathResolver = SourceFilePathResolver(mutableListOf(File(".")))
+        val sourceMapBuilder = SourceMap3Builder(outputFile, output, "", SourceMapBuilderConsumer(pathResolver))
         generatedProgram.accept(JsSourceGenerationVisitor(output, sourceMapBuilder))
         val code = output.toString()
         val generatedSourceMap = sourceMapBuilder.build()

js/js.translator/src/org/jetbrains/kotlin/js/facade/K2JSTranslator.java

@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.js.inline.JsInliner;
 import org.jetbrains.kotlin.js.inline.clean.LabeledBlockToDoWhileTransformation;
 import org.jetbrains.kotlin.js.inline.clean.RemoveUnusedImportsKt;
 import org.jetbrains.kotlin.js.inline.clean.ResolveTemporaryNamesKt;
+import org.jetbrains.kotlin.js.sourceMap.SourceFilePathResolver;
 import org.jetbrains.kotlin.js.translate.general.AstGenerationResult;
 import org.jetbrains.kotlin.js.translate.general.FileTranslationResult;
 import org.jetbrains.kotlin.js.translate.general.Translation;
@@ -45,10 +46,13 @@ import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil;
 import org.jetbrains.kotlin.serialization.js.ast.JsAstSerializer;
 
 import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static org.jetbrains.kotlin.diagnostics.DiagnosticUtils.hasError;
 
@@ -144,8 +148,18 @@ public final class K2JSTranslator {
         ExpandIsCallsKt.expandIsCalls(newFragments);
         ProgressIndicatorAndCompilationCanceledStatus.checkCanceled();
 
+        List<File> sourceRoots = config.getSourceMapRoots().stream().map(File::new).collect(Collectors.toList());
+        SourceFilePathResolver pathResolver = new SourceFilePathResolver(sourceRoots);
+
         Map<KtFile, FileTranslationResult> fileMap = new HashMap<>();
-        JsAstSerializer serializer = new JsAstSerializer();
+        JsAstSerializer serializer = new JsAstSerializer(file -> {
+            try {
+                return pathResolver.getPathRelativeToSourceRoots(file);
+            }
+            catch (IOException e) {
+                throw new RuntimeException("IO error occurred resolving path to source file", e);
+            }
+        });
         byte[] metadataHeader = null;
         boolean serializeFragments = config.getConfiguration().get(JSConfigurationKeys.SERIALIZE_FRAGMENTS, false);
         for (KtFile file : files) {

js/js.translator/src/org/jetbrains/kotlin/js/facade/SourceMapBuilderConsumer.java

@@ -20,21 +20,40 @@ import com.intellij.openapi.editor.Document;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.util.PairConsumer;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.js.backend.ast.JsLocation;
+import org.jetbrains.kotlin.js.sourceMap.SourceFilePathResolver;
 import org.jetbrains.kotlin.js.sourceMap.SourceMapBuilder;
 
+import java.io.File;
+import java.io.IOException;
+
 public class SourceMapBuilderConsumer implements PairConsumer<SourceMapBuilder, Object> {
+    @NotNull
+    private final SourceFilePathResolver pathResolver;
+
+    public SourceMapBuilderConsumer(@NotNull SourceFilePathResolver pathResolver) {
+        this.pathResolver = pathResolver;
+    }
+
     @Override
     public void consume(SourceMapBuilder builder, Object sourceInfo) {
         if (sourceInfo instanceof PsiElement) {
             PsiElement element = (PsiElement) sourceInfo;
-            PsiFile file = element.getContainingFile();
+            PsiFile psiFile = element.getContainingFile();
             int offset = element.getNode().getStartOffset();
-            Document document = file.getViewProvider().getDocument();
+            Document document = psiFile.getViewProvider().getDocument();
             assert document != null;
             int line = document.getLineNumber(offset);
             int column = offset - document.getLineStartOffset(line);
-            builder.addMapping(file.getViewProvider().getVirtualFile().getPath(), line, column);
+
+            File file = new File(psiFile.getViewProvider().getVirtualFile().getPath());
+            try {
+                builder.addMapping(pathResolver.getPathRelativeToSourceRoots(file), line, column);
+            }
+            catch (IOException e) {
+                throw new RuntimeException("IO error occurred generating source maps", e);
+            }
         }
         else if (sourceInfo instanceof JsLocation) {
             JsLocation location = (JsLocation) sourceInfo;

js/js.translator/src/org/jetbrains/kotlin/js/facade/TranslationResult.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.js.backend.ast.JsProgram
 import org.jetbrains.kotlin.js.config.JSConfigurationKeys
 import org.jetbrains.kotlin.js.config.JsConfig
 import org.jetbrains.kotlin.js.sourceMap.JsSourceGenerationVisitor
+import org.jetbrains.kotlin.js.sourceMap.SourceFilePathResolver
 import org.jetbrains.kotlin.js.sourceMap.SourceMap3Builder
 import org.jetbrains.kotlin.js.sourceMap.SourceMapBuilder
 import org.jetbrains.kotlin.js.translate.general.FileTranslationResult
@@ -58,9 +59,14 @@ abstract class TranslationResult protected constructor(val diagnostics: Diagnost
         fun getOutputFiles(outputFile: File, outputPrefixFile: File?, outputPostfixFile: File?): OutputFileCollection {
             val output = TextOutputImpl()
             val sourceMapBuilder =
-                    if (config.configuration.getBoolean(JSConfigurationKeys.SOURCE_MAP))
+                    if (config.configuration.getBoolean(JSConfigurationKeys.SOURCE_MAP)) {
-                        SourceMap3Builder(outputFile, output, SourceMapBuilderConsumer())
+                        val sourceRoots = config.sourceMapRoots.map { File(it) }
-                    else null
+                        val pathResolver = SourceFilePathResolver(sourceRoots)
+                        SourceMap3Builder(outputFile, output, config.sourceMapPrefix, SourceMapBuilderConsumer(pathResolver))
+                    }
+                    else {
+                        null
+                    }
 
             val code = getCode(output, sourceMapBuilder)
             val prefix = outputPrefixFile?.readText() ?: ""

js/js.translator/src/org/jetbrains/kotlin/js/sourceMap/SourceFilePathResolver.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * 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.jetbrains.kotlin.js.sourceMap;
+
+import com.intellij.openapi.util.text.StringUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.*;
+
+public class SourceFilePathResolver {
+    @NotNull
+    private final Set<File> sourceRoots;
+
+    @NotNull
+    private final Map<File, String> cache = new HashMap<>();
+
+    public SourceFilePathResolver(@NotNull List<File> sourceRoots) {
+        this.sourceRoots = new HashSet<>();
+        for (File sourceRoot : sourceRoots) {
+            this.sourceRoots.add(sourceRoot.getAbsoluteFile());
+        }
+    }
+
+    @NotNull
+    public String getPathRelativeToSourceRoots(@NotNull File file) throws IOException {
+        String path = cache.get(file);
+        if (path == null) {
+            path = calculatePathRelativeToSourceRoots(file);
+            cache.put(file, path);
+        }
+        return path;
+    }
+
+    private String calculatePathRelativeToSourceRoots(@NotNull File file) throws IOException {
+        List<String> parts = new ArrayList<>();
+        File currentFile = file.getCanonicalFile();
+
+        while (currentFile != null) {
+            if (sourceRoots.contains(currentFile)) {
+                if (parts.isEmpty()) {
+                    break;
+                }
+                Collections.reverse(parts);
+                return StringUtil.join(parts, File.separator);
+            }
+            parts.add(currentFile.getName());
+            currentFile = currentFile.getParentFile();
+        }
+        return file.getName();
+    }
+}

js/js.translator/src/org/jetbrains/kotlin/js/sourceMap/SourceMap3Builder.java

@@ -30,6 +30,7 @@ public class SourceMap3Builder implements SourceMapBuilder {
     private final StringBuilder out = new StringBuilder(8192);
     private final File generatedFile;
     private final TextOutput textOutput;
+    private final String pathPrefix;
     private final PairConsumer<SourceMapBuilder, Object> sourceInfoConsumer;
 
     private String lastSource;
@@ -50,9 +51,11 @@ public class SourceMap3Builder implements SourceMapBuilder {
     private int previousSourceLine;
     private int previousSourceColumn;
 
-    public SourceMap3Builder(File generatedFile, TextOutput textOutput, PairConsumer<SourceMapBuilder, Object> sourceInfoConsumer) {
+    public SourceMap3Builder(File generatedFile, TextOutput textOutput, String pathPrefix,
+            PairConsumer<SourceMapBuilder, Object> sourceInfoConsumer) {
         this.generatedFile = generatedFile;
         this.textOutput = textOutput;
+        this.pathPrefix = pathPrefix;
         this.sourceInfoConsumer = sourceInfoConsumer;
     }
 
@@ -83,7 +86,7 @@ public class SourceMap3Builder implements SourceMapBuilder {
             else {
                 isNotFirst = true;
             }
-            sb.append('"').append("file://").append(source).append('"');
+            sb.append('"').append(pathPrefix).append(source).append('"');
         }
         sb.append(']');
     }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinJsOptions.kt

@@ -48,6 +48,18 @@ interface KotlinJsOptions  : org.jetbrains.kotlin.gradle.dsl.KotlinCommonOptions
      */
      var sourceMap: kotlin.Boolean
 
+    /**
+     * Prefix for paths in a source map
+     * Default value: null
+     */
+     var sourceMapPrefix: kotlin.String?
+
+    /**
+     * Base directories which are used to calculate relative paths to source files in source map
+     * Default value: null
+     */
+     var sourceMapSourceRoots: kotlin.String?
+
     /**
      * Generate JS files for specific ECMA version
      * Possible values: "v5"

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinJsOptionsBase.kt

@@ -59,6 +59,16 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
         get() = sourceMapField ?: false
         set(value) { sourceMapField = value }
 
+    private var sourceMapPrefixField: kotlin.String?? = null
+    override var sourceMapPrefix: kotlin.String?
+        get() = sourceMapPrefixField ?: null
+        set(value) { sourceMapPrefixField = value }
+
+    private var sourceMapSourceRootsField: kotlin.String?? = null
+    override var sourceMapSourceRoots: kotlin.String?
+        get() = sourceMapSourceRootsField ?: null
+        set(value) { sourceMapSourceRootsField = value }
+
     private var targetField: kotlin.String? = null
     override var target: kotlin.String
         get() = targetField ?: "v5"
@@ -81,6 +91,8 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
         noStdlibField?.let { args.noStdlib = it }
         outputFileField?.let { args.outputFile = it }
         sourceMapField?.let { args.sourceMap = it }
+        sourceMapPrefixField?.let { args.sourceMapPrefix = it }
+        sourceMapSourceRootsField?.let { args.sourceMapSourceRoots = it }
         targetField?.let { args.target = it }
         typedArraysField?.let { args.typedArrays = it }
     }
@@ -98,6 +110,8 @@ internal fun org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments.fil
     noStdlib = true
     outputFile = null
     sourceMap = false
+    sourceMapPrefix = null
+    sourceMapSourceRoots = null
     target = "v5"
     typedArrays = false
 }