Add validate_asmjs.py tool to help unit-testing whether a build output is proper asm.js or not.

1 files changed, 72 insertions, 0 deletions

diff --git a/tools/validate_asmjs.py b/tools/validate_asmjs.py
new file mode 100644
index 00000000..85bf69ce
--- /dev/null
+++ b/tools/validate_asmjs.py
@@ -0,0 +1,72 @@
+#!/usr/bin/python
+
+# This is a helper script to validate a file for asm.js.
+
+# cmdline usage: 'python validate_asmjs.py filename.{html/js}'
+# Prints a line starting with 'OK: ' on success, and returns process exit code 0.
+# On failure, prints a line starting with 'FAIL: ', and returns a nonzero process exit code.
+
+# python usage: 'validate_asmjs("filename.{html/js}", muteOutput=True/False)'
+# Returns True/False depending on whether the file was valid asm.js.
+
+# This script depends on the SpiderMonkey JS engine, which must be present in PATH in order for this script to function.
+
+import subprocess, sys, re, tempfile, os, time
+
+# Given a .js file, returns True/False depending on if that file is valid asm.js
+def validate_asmjs_jsfile(filename, muteOutput):
+  process = subprocess.Popen(['js', '-c', filename], stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+  (stdout, stderr) = process.communicate()
+  if not muteOutput:
+    if len(stdout.strip()) > 0:
+      print stdout.strip()
+    if len(stderr.strip()) > 0:
+      # Pretty-print the output not to contain a spurious warning.
+      stderr = stderr.replace('warning: successfully compiled asm.js', ' successfully compiled asm.js')
+
+      print >> sys.stderr, stderr.strip()
+  if 'successfully compiled asm.js' in stderr:
+    return True
+  else:
+    return False
+
+# This tool takes as input a file built with Emscripten (either .html or .js) and validates it for asm.js.
+# Returns True/False denoting whether the file was valid asm.js. In case of a .html file, all <script>content</script> tags are searched,
+# and the ones containing a "use asm" section are validated.
+def validate_asmjs(filename, muteOutput):
+  if filename.endswith('.html'):
+    html = open(filename, 'r').read()
+    matches = re.findall('''<\w*script\w*.*?>(.*?)<\w*/script\w*>''', html, re.DOTALL | re.MULTILINE)
+    numAsmJsBlocks = 0
+    for match in matches:
+      if '"use asm"' in match:
+        numAsmJsBlocks = numAsmJsBlocks + 1
+        tmp_js = tempfile.mkstemp(suffix='.js')
+        os.write(tmp_js[0], match)
+        os.close(tmp_js[0])
+        valid_asmjs = validate_asmjs_jsfile(tmp_js[1], muteOutput)
+        os.remove(tmp_js[1])
+        if not valid_asmjs:
+          return False
+    if numAsmJsBlocks == 0:
+      if not muteOutput:
+        print >> sys.stderr, 'Error: the file does not contain any "use asm" modules.'
+      return False
+    else:
+      return True
+  else:
+    return validate_asmjs_jsfile(filename, muteOutput)
+
+def main():
+  if len(sys.argv) < 2:
+    print 'Usage: validate_asmjs <filename>'
+    return 2
+  if validate_asmjs(sys.argv[1], muteOutput=False):
+    print "OK: File '" + sys.argv[1] + "' validates as asm.js"
+    return 0
+  else:
+    print "FAIL: File '" + sys.argv[1] + "' is not valid asm.js"
+    return 1
+
+if __name__ == '__main__':
+  sys.exit(main())