[gobject-introspection] Allow overriding of dlltool name

[Colin Walters <walters src gnome org>]

commit 72b6df60f2d6bcd3628f57c794430f1eec4a04aa
Author: Nicola Fontana <ntd entidi it>
Date:   Mon Mar 23 15:57:14 2015 +0100

    Allow overriding of dlltool name
    
    Allow to override it with the DLLTOOL environment variable, leaving
    "dlltool" as a fallback when not defined so backward compatibility is
    ensured.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=761984

 Makefile.introspection |    2 +-
 giscanner/ccompiler.py |    3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/Makefile.introspection b/Makefile.introspection
index 1812df9..57bec20 100644
--- a/Makefile.introspection
+++ b/Makefile.introspection
@@ -84,7 +84,7 @@ _gir_silent_compiler = $(_gir_silent_compiler_$(V))
 _gir_silent_compiler_ = $(_gir_silent_compiler_$(_gir_verbosity))
 _gir_silent_compiler_0 = @echo "  GICOMP   $(1)";
 
-_gir_default_scanner_env = CPPFLAGS="$(CPPFLAGS)" CFLAGS="$(CFLAGS)" LDFLAGS="$(LDFLAGS)" CC="$(CC)" 
PKG_CONFIG="$(PKG_CONFIG)"
+_gir_default_scanner_env = CPPFLAGS="$(CPPFLAGS)" CFLAGS="$(CFLAGS)" LDFLAGS="$(LDFLAGS)" CC="$(CC)" 
PKG_CONFIG="$(PKG_CONFIG)" DLLTOOL="$(DLLTOOL)"
 
 #
 # Creates a GIR by scanning C headers/sources
diff --git a/giscanner/ccompiler.py b/giscanner/ccompiler.py
index 021345e..6ddbdfe 100644
--- a/giscanner/ccompiler.py
+++ b/giscanner/ccompiler.py
@@ -281,8 +281,7 @@ class CCompiler(object):
                     args.append(utils.which(os.environ.get('SHELL', 'sh.exe')))
                 args.extend(libtool)
                 args.append('--mode=execute')
-            # FIXME: it could have prefix (i686-w64-mingw32-dlltool.exe)
-            args.extend(['dlltool.exe', '--identify'])
+            args.extend([os.environ.get('DLLTOOL', 'dlltool.exe'), '--identify'])
             proc = subprocess.Popen([self.compiler_cmd, '-print-search-dirs'],
                                     stdout=subprocess.PIPE)
             o, e = proc.communicate()