Associate partial source map with each code block in Universe.generatedCode.

lib/compiler/implementation/source_map_builder.dart

Index: lib/compiler/implementation/source_map_builder.dart
diff --git a/lib/compiler/implementation/source_map_builder.dart b/lib/compiler/implementation/source_map_builder.dart
index 3e5fb6f991deed84d837ca4f90d1a746b3be4055..621a352acc6614e272d537165213fa52d0a9edc9 100644
--- a/lib/compiler/implementation/source_map_builder.dart
+++ b/lib/compiler/implementation/source_map_builder.dart
@@ -7,18 +7,7 @@
 #import('dart:json');
 
 #import('source_file.dart');
-
-class SourceMappingEntry {
-  SourceFile sourceFile;
-  int sourceOffset;
-  int targetOffset;
-  String sourceName;
-
-  SourceMappingEntry(this.sourceFile,
-                     this.sourceOffset,
-                     this.targetOffset,
-                     [this.sourceName]);
-}
+#import('ssa/ssa.dart');
 
 class SourceMapBuilder {
   static final int VLQ_BASE_SHIFT = 5;
@@ -28,6 +17,8 @@ class SourceMapBuilder {
   static final String BASE64_DIGITS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn'
                                       'opqrstuvwxyz0123456789+/';
 
+  List<_Block> blocks;
+
   Map<String, int> sourceUrlMap;
   List<String> sourceUrlList;
   Map<String, int> sourceNameMap;
@@ -42,6 +33,8 @@ class SourceMapBuilder {
   bool firstEntryInLine;
 
   SourceMapBuilder() {
+    blocks = new List<_Block>();
+
     sourceUrlMap = new Map<String, int>();
     sourceUrlList = new List<String>();
     sourceNameMap = new Map<String, int>();
@@ -56,13 +49,21 @@ class SourceMapBuilder {
     firstEntryInLine = true;
   }
 
-  String build(List<SourceMappingEntry> mappingEntries, SourceFile targetFile) {
+  void addCodeBlock(List<SourceMappingEntry> sourceMappings, int offset) {
+    if (sourceMappings !== null) {
+      blocks.add(new _Block(sourceMappings, offset));
+    }
+  }
+
+  String build(SourceFile targetFile) {
     StringBuffer buffer = new StringBuffer();
     buffer.add('{\n');
     buffer.add('  "version": 3,\n');
     buffer.add('  "mappings": "');
-    mappingEntries.forEach((SourceMappingEntry entry) {
-      writeEntry(entry, targetFile, buffer);
+    blocks.forEach((_Block block) {
+      block.sourceMapings.forEach((SourceMappingEntry entry) {
+        writeEntry(entry, targetFile, block.offset, buffer);
+      });
     });
     buffer.add('",\n');
     // TODO(podivilov): serialize lists directly to buffer.
@@ -74,12 +75,14 @@ class SourceMapBuilder {
 
   void writeEntry(SourceMappingEntry entry,
                   SourceFile targetFile,
+                  int targetOffset,
                   StringBuffer output) {
     if (entry.sourceFile === null) {
       return;
     }
-    int targetLine = targetFile.getLine(entry.targetOffset);
-    int targetColumn = targetFile.getColumn(targetLine, entry.targetOffset);
+    int totalTargetOffset = targetOffset + entry.targetOffset;
+    int targetLine = targetFile.getLine(totalTargetOffset);
+    int targetColumn = targetFile.getColumn(targetLine, totalTargetOffset);
     String sourceUrl = entry.sourceFile.filename;
     int sourceLine = entry.sourceFile.getLine(entry.sourceOffset);
     int sourceColumn = entry.sourceFile.getColumn(sourceLine,
@@ -149,3 +152,9 @@ class SourceMapBuilder {
     } while (value > 0);
   }
 }
+
+class _Block {
+  List<SourceMappingEntry> sourceMapings;
+  int offset;
+  _Block(this.sourceMapings, this.offset);
+}