2 files changed, 16 insertions, 8 deletions

diff --git a/emcc b/emcc
index 8dc7652a..5b6d00dc 100755
--- a/emcc
+++ b/emcc
@@ -1585,9 +1585,9 @@ try:
         else:
           logging.debug('did not see memory initialization')
 
-  def generate_source_maps(filename, map_file_base_name):
+  def generate_source_map(filename, map_file_base_name, offset=0):
     jsrun.run_js(shared.path_from_root('tools', 'sourcemapper.js'),
-      shared.NODE_JS, [filename, os.getcwd(), map_file_base_name])
+      shared.NODE_JS, [filename, os.getcwd(), map_file_base_name, str(offset)])
 
   # If we were asked to also generate HTML, do that
   if final_suffix == 'html':
@@ -1595,7 +1595,12 @@ try:
     shell = open(shell_path).read()
     html = open(target, 'w')
     if not Compression.on:
-      if keep_llvm_debug and keep_js_debug: generate_source_maps(final, target)
+      if keep_llvm_debug and keep_js_debug:
+        match = re.match('.*?<script[^>]*>{{{ SCRIPT_CODE }}}</script>', shell,
+            re.DOTALL)
+        if match is None:
+          raise RuntimeError('Could not find script insertion point')
+        generate_source_map(final, target, match.group().count('\n'))
       html.write(shell.replace('{{{ SCRIPT_CODE }}}', open(final).read()))
     else:
       # Compress the main code
@@ -1666,7 +1671,7 @@ try:
         from tools.split import split_javascript_file
         split_javascript_file(final, unsuffixed(target), split_js_file)
     else:
-        if keep_llvm_debug and keep_js_debug: generate_source_maps(final, target)
+        if keep_llvm_debug and keep_js_debug: generate_source_map(final, target)
 
         # copy final JS to output
         shutil.move(final, target)
diff --git a/tools/sourcemapper.js b/tools/sourcemapper.js
index fce9251f..c7021a0f 100755
--- a/tools/sourcemapper.js
+++ b/tools/sourcemapper.js
@@ -63,7 +63,7 @@ function extractComments(source, commentHandler) {
   }
 }
 
-function generateMap(fileName, sourceRoot, mapFileBaseName) {
+function generateMap(fileName, sourceRoot, mapFileBaseName, generatedLineOffset) {
   var fs = require('fs');
   var path = require('path');
   var SourceMapGenerator = require('source-map').SourceMapGenerator;
@@ -91,7 +91,7 @@ function generateMap(fileName, sourceRoot, mapFileBaseName) {
     }
 
     generator.addMapping({
-      generated: { line: generatedLineNumber, column: 0 },
+      generated: { line: generatedLineNumber + generatedLineOffset, column: 0 },
       original: { line: originalLineNumber, column: 0 },
       source: originalFileName
     });
@@ -108,11 +108,14 @@ function generateMap(fileName, sourceRoot, mapFileBaseName) {
 if (require.main === module) {
   if (process.argv.length < 3) {
     console.log('Usage: ./sourcemapper.js <filename> <source root (default: .)> ' +
-                '<map file basename (default: filename)>');
+                '<map file basename (default: filename)>' +
+                '<generated line offset (default: 0)>');
     process.exit(1);
   } else {
     var sourceRoot = process.argv.length > 3 ? process.argv[3] : ".";
     var mapFileBaseName = process.argv.length > 4 ? process.argv[4] : process.argv[2];
-    generateMap(process.argv[2], sourceRoot, mapFileBaseName);
+    var generatedLineOffset = process.argv.length > 5 ?
+        parseInt(process.argv[5], 10) : 0;
+    generateMap(process.argv[2], sourceRoot, mapFileBaseName, generatedLineOffset);
   }
 }