[gobject-introspection] ccompiler.py: Win32: Use tempfile for resolving libs

[Chun-wei Fan <fanchunwei src gnome org>]

commit 444648d6a8b97250e737bc46d00d8278a5c205d4
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Mar 15 00:58:08 2016 +0800

    ccompiler.py: Win32: Use tempfile for resolving libs
    
    When using the NMake Makefile within the Visual Studio projects, as we are
    using dumpbin to resolve the .lib file that we link to, the outputs of
    dumpbin is captured by the Visual Studio output panel, which causes it not
    to be processed by proc.communicate().  This is due to dumpbin being an
    integrated component of Visual Studio.  In order to remedy this, we need to
    use a temp file, and use the /out:<tempfile> flag, and look for the DLL
    that is linked to by the .lib that we pass in.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763739

 giscanner/ccompiler.py |   57 ++++++++++++++++++++++++++++++-----------------
 1 files changed, 36 insertions(+), 21 deletions(-)
---
diff --git a/giscanner/ccompiler.py b/giscanner/ccompiler.py
index c83bd7e..2582338 100644
--- a/giscanner/ccompiler.py
+++ b/giscanner/ccompiler.py
@@ -20,6 +20,7 @@
 
 import os
 import subprocess
+import tempfile
 
 import sys
 import distutils
@@ -269,7 +270,11 @@ class CCompiler(object):
 
             # Use the dumpbin utility that's included in
             # every Visual C++ installation to find out which
-            # DLL the library gets linked to
+            # DLL the .lib gets linked to.
+            # dumpbin -symbols something.lib gives the
+            # filename of DLL without the '.dll' extension that something.lib
+            # links to, in the line that contains
+            # __IMPORT_DESCRIPTOR_<dll_filename_that_something.lib_links_to>
             args.append('dumpbin.exe')
             args.append('-symbols')
 
@@ -310,26 +315,36 @@ class CCompiler(object):
                         break
                     implib = os.path.join(l, c)
                     if os.path.exists(implib):
-                        proc = subprocess.Popen(args + [implib],
-                                                stdout=subprocess.PIPE)
-                        o, e = proc.communicate()
-                        for line in o.decode('ascii').splitlines():
-                            if self.check_is_msvc():
-                                # On Visual Studio, dumpbin -symbols something.lib gives the
-                                # filename of DLL without the '.dll' extension that something.lib
-                                # links to, in the line that contains
-                                # __IMPORT_DESCRIPTOR_<dll_filename_that_something.lib_links_to>
-
-                                if '__IMPORT_DESCRIPTOR_' in line:
-                                    line_tokens = line.split()
-                                    for item in line_tokens:
-                                        if item.startswith('__IMPORT_DESCRIPTOR_'):
-                                            shlibs.append(item[20:] + '.dll')
-                                            found = True
-                                            break
-                                if found:
-                                    break
-                            else:
+                        if self.check_is_msvc():
+                            tmp_fd, tmp_filename = \
+                                tempfile.mkstemp(prefix='g-ir-win32-resolve-lib-')
+
+                            # This is dumb, but it is life... Windows does not like one
+                            # trying to write to a file when its FD is not closed first,
+                            # when we use a flag in a program to do so.  So, close,
+                            # write to temp file with dumpbin and *then* re-open the
+                            # file for reading.
+                            os.close(tmp_fd)
+                            output_flag = ['-out:' + tmp_filename]
+                            proc = subprocess.call(args + [implib] + output_flag,
+                                                   stdout=subprocess.PIPE)
+                            with open(tmp_filename, 'rb') as tmp_fileobj:
+                                for line in tmp_fileobj.read().splitlines():
+
+                                    if '__IMPORT_DESCRIPTOR_' in line:
+                                        line_tokens = line.split()
+                                        for item in line_tokens:
+                                            if item.startswith('__IMPORT_DESCRIPTOR_'):
+                                                shlibs.append(item[20:] + '.dll')
+                                                found = True
+                                                break
+                            tmp_fileobj.close()
+                            os.unlink(tmp_filename)
+                        else:
+                            proc = subprocess.Popen(args + [implib],
+                                                    stdout=subprocess.PIPE)
+                            o, e = proc.communicate()
+                            for line in o.decode('ascii').splitlines():
                                 shlibs.append(line)
                                 found = True
                                 break