[gobject-introspection/tools.windows] g-ir-tool-template.in: Don't hardcode /usr/bin/env

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

commit 0da5d92ad30c37dbedb5b3a8b98e436006961f9e
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Aug 21 00:30:46 2018 +0800

    g-ir-tool-template.in: Don't hardcode /usr/bin/env
    
    For Visual Studio builds, it is likely that we specify a specific Python
    installation as there may well be multiple Python installations, but
    _giscanner.pyd get tied to the particular Python DLL that it was built
    with.  So, we cannot just use /usr/bin/env python3 in such a case on
    Visual Studio, but instead we use the full path to the Python executable
    in the shebang so that the correct Python installation is used, when
    running the installed scripts.  This is necessary as Meson could bump
    the Python version it requires but _giscanner.pyd could not be used on
    the newer Python that is required due to differences in CRTs being used
    for the builds and the CRT that CPython, for instance, is linked to.
    
    We continue to use /usr/bin/env python[2|3] for other builds.

 Makefile-tools.am           |  2 +-
 tools/g-ir-tool-template.in |  2 +-
 tools/meson.build           | 10 +++++++++-
 3 files changed, 11 insertions(+), 3 deletions(-)
---
diff --git a/Makefile-tools.am b/Makefile-tools.am
index 8c4a069b..ccf0ec13 100644
--- a/Makefile-tools.am
+++ b/Makefile-tools.am
@@ -9,7 +9,7 @@ EXTRA_DIST +=                           \
        tools/g-ir-tool-template.in \
        tools/meson.build
 
-TOOL_SUBSTITUTIONS = -e s,@libdir\@,$(libdir), -e s,@datarootdir\@,$(datarootdir), -e s,@PYTHON\@,$(PYTHON),
+TOOL_SUBSTITUTIONS = -e s,@libdir\@,$(libdir), -e s,@datarootdir\@,$(datarootdir), -e 
s,@PYTHON_ENV\@,\/usr\/bin\/env, -e s,@PYTHON\@,$(PYTHON),
 
 g-ir-scanner: tools/g-ir-tool-template.in _giscanner.la Makefile
        $(AM_V_GEN) sed $(TOOL_SUBSTITUTIONS) -e s,@TOOL_MODULE\@,scannermain, -e 
s,@TOOL_FUNCTION\@,scanner_main, $< > $@.tmp && mv $@.tmp $@
diff --git a/tools/g-ir-tool-template.in b/tools/g-ir-tool-template.in
index 83279bd4..0fcd440c 100755
--- a/tools/g-ir-tool-template.in
+++ b/tools/g-ir-tool-template.in
@@ -1,4 +1,4 @@
-#!/usr/bin/env @PYTHON@
+#!@PYTHON_ENV@ @PYTHON@
 # -*- Mode: Python -*-
 # GObject-Introspection - a framework for introspecting GObject libraries
 # Copyright (C) 2008  Johan Dahlin
diff --git a/tools/meson.build b/tools/meson.build
index 73472664..ffa2d2eb 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -9,12 +9,20 @@ if get_option('doctool')
   tools += [['g-ir-doc-tool', 'docmain', 'doc_main']]
 endif
 
-python_name = 'python@0@'.format(python.language_version().split('.')[0])
+if cc.get_id() == 'msvc'
+  python_env = ''
+  python_name = python.get_variable('prefix') + '\\python'
+else
+  python_env = '/usr/bin/env'
+  python_name = 'python@0@'.format(python.language_version().split('.')[0])
+endif
+
 tool_output = []
 foreach tool : tools
   tools_conf = configuration_data()
   tools_conf.set('libdir', libdir_abs)
   tools_conf.set('datarootdir', datadir_abs)
+  tools_conf.set('PYTHON_ENV', python_env)
   tools_conf.set('PYTHON', python_name)
 
   tools_conf.set('TOOL_MODULE', tool[1])