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

1 files changed, 36 insertions, 21 deletions

diff --git a/giscanner/ccompiler.py b/giscanner/ccompiler.py
index c83bd7ea..25823382 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