Bug 1291944 - Verify makensis binary is 32-bits; r=glandium

This required implementing a utility function to resolve the binary
type. I used GetBinaryTypeW via ctypes because this seems the fastest.
I arbitrarily limited the function to testing 32-bit and 64-bit Windows
executables because hopefully those are the only executables we'll
ever encounter. We can expand the binary detection later, if needed.
This includes support for running on non-Windows platforms.

MozReview-Commit-ID: CYwyDWQrePc

--HG--
extra : rebase_source : 8fd7ca7f253d9e9e18d64784652a5ff934ad2272

build/moz.configure/util.configure

@@ -62,6 +62,32 @@ def normsep(path):
     return mozpath.normsep(path)
 
 
+@imports('ctypes')
+@imports(_from='ctypes', _import='wintypes')
+@imports(_from='mozbuild.configure.constants', _import='WindowsBinaryType')
+def windows_binary_type(path):
+    """Obtain the type of a binary on Windows.
+
+    Returns WindowsBinaryType constant.
+    """
+    GetBinaryTypeW = ctypes.windll.kernel32.GetBinaryTypeW
+    GetBinaryTypeW.argtypes = [wintypes.LPWSTR, wintypes.POINTER(wintypes.DWORD)]
+    GetBinaryTypeW.restype = wintypes.BOOL
+
+    bin_type = wintypes.DWORD()
+    res = GetBinaryTypeW(path, ctypes.byref(bin_type))
+    if not res:
+        die('could not obtain binary type of %s' % path)
+
+    if bin_type.value == 0:
+        return WindowsBinaryType('win32')
+    elif bin_type.value == 6:
+        return WindowsBinaryType('win64')
+    # If we see another binary type, something is likely horribly wrong.
+    else:
+        die('unsupported binary type on %s: %s' % (path, bin_type))
+
+
 @imports('ctypes')
 @imports(_from='ctypes', _import='wintypes')
 def get_GetShortPathNameW():

moz.configure

@@ -295,6 +295,16 @@ def nsis_version(nsis):
 
     return ver
 
+# And that makensis is 32-bit.
+@depends_if(nsis)
+@checking('for 32-bit NSIS')
+def nsis_binary_type(nsis):
+    bin_type = windows_binary_type(nsis)
+    if bin_type != 'win32':
+        raise FatalCheckError('%s is not a 32-bit Windows application' % nsis)
+
+    return 'yes'
+
 
 # Fallthrough to autoconf-based configure
 include('build/moz.configure/old.configure')

python/mozbuild/mozbuild/configure/constants.py

@@ -63,6 +63,11 @@
     'little',
 )
 
+WindowsBinaryType = EnumString.subclass(
+    'win32',
+    'win64',
+)
+
 # The order of those checks matter
 CPU_preprocessor_checks = OrderedDict((
     ('x86', '__i386__ || _M_IX86'),