JS: add DCE devmode. Fix mapping paths in source maps

See KT-20210, KT-21307

js/js.dce/src/org/jetbrains/kotlin/js/dce/DeadCodeElimination.kt

@@ -120,8 +120,12 @@ class DeadCodeElimination(private val logConsumer: (DCELogLevel, String) -> Unit
                 val sourceMapFile = File(file.outputPath + ".map")
                 val textOutput = TextOutputImpl()
                 val sourceMapBuilder = SourceMap3Builder(File(file.outputPath), textOutput, "")
-                val sourcePathResolver = SourceFilePathResolver(mutableListOf(), File(file.outputPath).parentFile)
-                val consumer = SourceMapBuilderConsumer(sourceMapBuilder, sourcePathResolver, true, true)
+
+                val inputFile = File(file.resource.name)
+                val sourceBaseDir = if (inputFile.exists()) inputFile.parentFile else File(".")
+
+                val sourcePathResolver = SourceFilePathResolver(emptyList(), File(file.outputPath).parentFile)
+                val consumer = SourceMapBuilderConsumer(sourceBaseDir, sourceMapBuilder, sourcePathResolver, true, true)
                 block.accept(JsToStringGenerationVisitor(textOutput, consumer))
                 val sourceMapContent = sourceMapBuilder.build()
                 sourceMapBuilder.addLink()

js/js.dce/src/org/jetbrains/kotlin/js/dce/InputResource.kt

@@ -21,13 +21,19 @@ import java.io.FileInputStream
 import java.io.InputStream
 import java.util.zip.ZipFile
 
-class InputResource(val name: String, val reader: () -> InputStream) {
+class InputResource(val name: String, val lastModified: () -> Long, val reader: () -> InputStream) {
     companion object {
-        fun file(path: String): InputResource = InputResource(path) { FileInputStream(File(path)) }
+        fun file(path: String): InputResource = InputResource(path, { File(path).lastModified() }) { FileInputStream(File(path)) }
 
-        fun zipFile(path: String, entryPath: String): InputResource = InputResource("$path!$entryPath") {
-            val zipFile = ZipFile(path)
-            zipFile.getInputStream(zipFile.getEntry(entryPath))
+        fun zipFile(path: String, entryPath: String): InputResource =
+                InputResource("$path!$entryPath", { getZipModificationTime(path, entryPath) }) {
+                    val zipFile = ZipFile(path)
+                    zipFile.getInputStream(zipFile.getEntry(entryPath))
+                }
+
+        private fun getZipModificationTime(path: String, entryPath: String): Long {
+            val result = ZipFile(path).getEntry(entryPath).time
+            return if (result != -1L) result else File(path).lastModified()
         }
     }
 }

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

@@ -460,7 +460,8 @@ abstract class BasicBoxTest(
         val output = TextOutputImpl()
         val pathResolver = SourceFilePathResolver(mutableListOf(File(".")), null)
         val sourceMapBuilder = SourceMap3Builder(outputFile, output, "")
-        generatedProgram.accept(JsToStringGenerationVisitor(output, SourceMapBuilderConsumer(sourceMapBuilder, pathResolver, false, false)))
+        generatedProgram.accept(JsToStringGenerationVisitor(
+                output, SourceMapBuilderConsumer(File("."), sourceMapBuilder, pathResolver, false, false)))
         val code = output.toString()
         val generatedSourceMap = sourceMapBuilder.build()
 

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

@@ -34,6 +34,9 @@ import java.util.List;
 import java.util.function.Supplier;
 
 public class SourceMapBuilderConsumer implements SourceLocationConsumer {
+    @NotNull
+    private final File sourceBaseDir;
+
     @NotNull
     private final SourceMapMappingConsumer mappingConsumer;
 
@@ -48,10 +51,12 @@ public class SourceMapBuilderConsumer implements SourceLocationConsumer {
     private final List<Object> sourceStack = new ArrayList<>();
 
     public SourceMapBuilderConsumer(
+            @NotNull File sourceBaseDir,
             @NotNull SourceMapMappingConsumer mappingConsumer,
             @NotNull SourceFilePathResolver pathResolver,
             boolean provideCurrentModuleContent, boolean provideExternalModuleContent
     ) {
+        this.sourceBaseDir = sourceBaseDir;
         this.mappingConsumer = mappingConsumer;
         this.pathResolver = pathResolver;
         this.provideCurrentModuleContent = provideCurrentModuleContent;
@@ -109,7 +114,23 @@ public class SourceMapBuilderConsumer implements SourceLocationConsumer {
         else if (sourceInfo instanceof JsLocationWithSource) {
             JsLocationWithSource location = (JsLocationWithSource) sourceInfo;
             Supplier<Reader> contentSupplier = provideExternalModuleContent ? location.getSourceProvider()::invoke : () -> null;
-            mappingConsumer.addMapping(location.getFile(), location.getIdentityObject(), contentSupplier,
+            String path;
+
+            File absFile = new File(location.getFile()).isAbsolute() ?
+                           new File(location.getFile()) :
+                           new File(sourceBaseDir, location.getFile());
+            if (absFile.isAbsolute()) {
+                try {
+                    path = pathResolver.getPathRelativeToSourceRoots(absFile);
+                }
+                catch (IOException e) {
+                    path = location.getFile();
+                }
+            }
+            else {
+                path = location.getFile();
+            }
+            mappingConsumer.addMapping(path, location.getIdentityObject(), contentSupplier,
                                location.getStartLine(), location.getStartChar());
         }
     }

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

@@ -69,6 +69,7 @@ abstract class TranslationResult protected constructor(val diagnostics: Diagnost
                         val sourceMapContentEmbedding = config.sourceMapContentEmbedding
                         val pathResolver = SourceFilePathResolver.create(config)
                         SourceMapBuilderConsumer(
+                                File("."),
                                 sourceMapBuilder,
                                 pathResolver,
                                 sourceMapContentEmbedding == SourceMapSourceEmbedding.ALWAYS,