do not remove braces in asmLastOpts when emitting source maps #3466

Author: kripken

tests/test_core.py

@@ -6914,23 +6914,11 @@ def build_and_check():
       import json
       Building.emcc(src_filename, Settings.serialize() + self.emcc_args +
           Building.COMPILER_TEST_OPTS, out_filename, stderr=PIPE)
-      with open(out_filename) as f: out_file = f.read()
       # after removing the @line and @sourceMappingURL comments, the build
       # result should be identical to the non-source-mapped debug version.
       # this is worth checking because the parser AST swaps strings for token
       # objects when generating source maps, so we want to make sure the
       # optimizer can deal with both types.
-      out_file = re.sub(' *//[@#].*$', '', out_file, flags=re.MULTILINE)
-      def clean(code):
-        code = code.replace('// EMSCRIPTEN_GENERATED_FUNCTIONS: ["_malloc","__Z3foov","_free","_main"]', '')
-        code = re.sub(';', ';\n', code) # put statements each on a new line
-        code = re.sub(r'\n+[ \n]*\n+', '\n', code)
-        code = re.sub(' L\d+ ?:', '', code) # ignore labels; they can change in each compile
-        code = code.replace('{\n}', '{}')
-        lines = code.split('\n')
-        lines = filter(lambda line: ': do {' not in line and ' break L' not in line, lines) # ignore labels; they can change in each compile
-        return '\n'.join(sorted(lines))
-      self.assertIdentical(clean(no_maps_file), clean(out_file))
       map_filename = out_filename + '.map'
       data = json.load(open(map_filename, 'r'))
       self.assertPathsIdentical(out_filename, data['file'])

tests/test_other.py

@@ -4848,3 +4848,24 @@ def test_file_packager_eval(self):
     out, err = Popen([PYTHON, FILE_PACKAGER, 'test.data', '--preload', 'temp.txt', '--no-closure'], stdout=PIPE, stderr=PIPE).communicate()
     assert BAD not in out, out[max(out.index(BAD)-80, 0) : min(out.index(BAD)+80, len(out)-1)]
 
+  def test_debug_asmLastOpts(self):
+    open('src.c', 'w').write(r'''
+#include <stdio.h>
+struct Dtlink_t
+{   struct Dtlink_t*   right;  /* right child      */
+        union
+        { unsigned int  _hash;  /* hash value       */
+          struct Dtlink_t* _left;  /* left child       */
+        } hl;
+};
+int treecount(register struct Dtlink_t* e)
+{
+  return e ? treecount(e->hl._left) + treecount(e->right) + 1 : 0;
+}
+int main() {
+  printf("hello, world!\n");
+}
+''')
+    out, err = Popen([PYTHON, EMCC, 'src.c', '-s', 'EXPORTED_FUNCTIONS=["_main", "_treecount"]', '--minify', '0', '-g4', '-Oz']).communicate()
+    self.assertContained('hello, world!', run_js('a.out.js'))
+

tools/js-optimizer.js

@@ -7443,12 +7443,14 @@ function asmLastOpts(ast) {
       var stats = getStatements(node);
       if (stats) statsStack.pop();
     });
-    // convert  { singleton }  into  singleton
-    traverse(fun, function(node, type) {
-      if (type === 'block' && node[1] && node[1].length === 1) {
-        return node[1][0];
-      }
-    });
+    if (!debug) { // dangerous in debug mode, as without braces things can end up on the same line, together with comments
+      // convert  { singleton }  into  singleton
+      traverse(fun, function(node, type) {
+        if (type === 'block' && node[1] && node[1].length === 1) {
+          return node[1][0];
+        }
+      });
+    }
   });
 }