error on undefined symbols in asm.js mode, since it breaks validation and must be corrected

2 files changed, 4 insertions, 2 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 4263618a..38029377 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -513,7 +513,9 @@ function JSify(data, functionsOnly, givenFunctions) {
         item.JS = addFromLibrary(shortident);
       } else if (!LibraryManager.library.hasOwnProperty(shortident + '__inline')) {
         item.JS = 'var ' + item.ident + '; // stub for ' + item.ident;
-        if (WARN_ON_UNDEFINED_SYMBOLS || ASM_JS) { // always warn on undefs in asm, since it breaks validation
+        if (ASM_JS) {
+          throw 'Unresolved symbol: ' + item.ident + ', this must be corrected for asm.js validation to succeed';
+        } else if (WARN_ON_UNDEFINED_SYMBOLS) {
           warn('Unresolved symbol: ' + item.ident);
         }
       }
diff --git a/tests/runner.py b/tests/runner.py
index f2a0bd4e..9ca444fb 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -9329,7 +9329,7 @@ f.close()
       filename = self.in_dir('src.cpp')
       open(filename, 'w').write(src)
       out, err = Popen([PYTHON, EMCC, filename, '-s', 'ASM_JS=1', '-O2'], stderr=PIPE).communicate()
-      assert 'Warning: Unresolved symbol' in err, 'always warn on undefs in asm, since it breaks validation'
+      assert 'Unresolved symbol' in err, 'always warn on undefs in asm, since it breaks validation: ' + err
 
     def test_redundant_link(self):
       lib = "int mult() { return 1; }"