[gobject-introspection] build: use the detected pkg-config

[Rico Tzschichholz <ricotz src gnome org>]

commit 0f210321c4afdcf70debba42bebf5077932d7056
Author: Saleem Abdulrasool <compnerd compnerd org>
Date:   Sun Mar 22 14:04:56 2015 -0700

    build: use the detected pkg-config
    
    Rather than assuming that pkg-config is spelt pkg-config, use the environment
    variable $PKG_CONFIG which is the actual detected pkg-config spelling.  This is
    particularly important when cross-compiling, where the pkg-config may be
    prefixed with the target and will actually provide a different result from the
    build pkg-config which may be available unprefixed.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746669

 Makefile-gir.am          |   18 +++++++++---------
 giscanner/scannermain.py |    2 +-
 2 files changed, 10 insertions(+), 10 deletions(-)
---
diff --git a/Makefile-gir.am b/Makefile-gir.am
index 52f7ee3..9aca664 100644
--- a/Makefile-gir.am
+++ b/Makefile-gir.am
@@ -55,8 +55,8 @@ else
 endif
 
 # glib
-GLIB_INCLUDEDIR=$(shell pkg-config --variable=includedir glib-2.0)/glib-2.0
-GLIB_LIBDIR=$(shell pkg-config --variable=libdir glib-2.0)
+GLIB_INCLUDEDIR=$(shell "${PKG_CONFIG}" --variable=includedir glib-2.0)/glib-2.0
+GLIB_LIBDIR=$(shell "${PKG_CONFIG}" --variable=libdir glib-2.0)
 
 GLIB_LIBRARY=glib-2.0
 
@@ -92,8 +92,8 @@ GLib-2.0.gir: g-ir-scanner g-ir-compiler$(EXEEXT)
 gir/DBusGLib-1.0.typelib: GObject-2.0.gir
 
 # gobject
-GOBJECT_INCLUDEDIR=$(shell pkg-config --variable=includedir gobject-2.0)/glib-2.0
-GOBJECT_LIBDIR=$(shell pkg-config --variable=libdir gobject-2.0)
+GOBJECT_INCLUDEDIR=$(shell "${PKG_CONFIG}" --variable=includedir gobject-2.0)/glib-2.0
+GOBJECT_LIBDIR=$(shell "${PKG_CONFIG}" --variable=libdir gobject-2.0)
 
 GOBJECT_LIBRARY=gobject-2.0
 
@@ -120,8 +120,8 @@ GObject_2_0_gir_FILES = \
 BUILT_GIRSOURCES += GObject-2.0.gir
 
 # gmodule
-GMODULE_INCLUDEDIR=$(shell pkg-config --variable=includedir gmodule-2.0)/glib-2.0
-GMODULE_LIBDIR=$(shell pkg-config --variable=libdir gmodule-2.0)
+GMODULE_INCLUDEDIR=$(shell "${PKG_CONFIG}" --variable=includedir gmodule-2.0)/glib-2.0
+GMODULE_LIBDIR=$(shell "${PKG_CONFIG}" --variable=libdir gmodule-2.0)
 
 GMODULE_LIBRARY=gmodule-2.0
 
@@ -146,13 +146,13 @@ GModule_2_0_gir_FILES = $(GLIB_INCLUDEDIR)/gmodule.h \
 BUILT_GIRSOURCES += GModule-2.0.gir
 
 # gio
-GIO_INCLUDEDIR=$(shell pkg-config --variable=includedir gio-2.0)/glib-2.0
-GIO_LIBDIR=$(shell pkg-config --variable=libdir gio-2.0)
+GIO_INCLUDEDIR=$(shell "${PKG_CONFIG}" --variable=includedir gio-2.0)/glib-2.0
+GIO_LIBDIR=$(shell "${PKG_CONFIG}" --variable=libdir gio-2.0)
 
 GIO_LIBRARY=gio-2.0
 
 if HAVE_GIO_UNIX
-GIO_UNIX_HDRS=$(shell pkg-config --variable=includedir gio-unix-2.0)/gio-unix-2.0/gio/*.h
+GIO_UNIX_HDRS=$(shell "${PKG_CONFIG}" --variable=includedir gio-unix-2.0)/gio-unix-2.0/gio/*.h
 GIO_UNIX_PACKAGES = gio-unix-2.0
 else
 GIO_UNIX_HDRS=
diff --git a/giscanner/scannermain.py b/giscanner/scannermain.py
index bca4a88..b36284d 100755
--- a/giscanner/scannermain.py
+++ b/giscanner/scannermain.py
@@ -280,7 +280,7 @@ def process_options(output, allowed_flags):
 
 
 def process_packages(options, packages):
-    args = ['pkg-config', '--cflags']
+    args = [os.environ.get('PKG_CONFIG', 'pkg-config'), '--cflags']
     args.extend(packages)
     output = subprocess.Popen(args,
                               stdout=subprocess.PIPE).communicate()[0]