cmake: allow to use pkg-config for windows builds as well

If the user has an appropriate pkg-config wrapper,
e.g. i686-w64-mingw32-pkg-config (or building natively on mingw and
has pkg-config or pkg-config-lite installed), it can be used to locate
libusb-1.0 properly. For cross-compiling
-DPKG_CONFIG_EXECUTABLE=`which i686-w64-mingw32-pkg-config`
needs to be explicitly set.

It still doesn't prevent pkg-config-less operation, i.e. the user can
specify something like
-DLIBUSB_INCLUDE_DIR=~/i686-w64-mingw32-root/usr/include/libusb-1.0
and the build will succeed even when no pkg-config executable is
present.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>

diff --git a/cmake/FindUSB1.cmake b/cmake/FindUSB1.cmake
index ebcac99..8cb9229 100644 (file)
--- a/cmake/FindUSB1.cmake
+++ b/cmake/FindUSB1.cmake
@@ -17,12 +17,10 @@ if (LIBUSB_INCLUDE_DIR AND LIBUSB_LIBRARIES)
   set(LIBUSB_FOUND TRUE)
 
 else (LIBUSB_INCLUDE_DIR AND LIBUSB_LIBRARIES)
-  IF (NOT WIN32)
-    # use pkg-config to get the directories and then use these values
-    # in the FIND_PATH() and FIND_LIBRARY() calls
-    find_package(PkgConfig)
-    pkg_check_modules(PC_LIBUSB libusb-1.0)
-  ENDIF(NOT WIN32)
+  # use pkg-config to get the directories and then use these values
+  # in the FIND_PATH() and FIND_LIBRARY() calls
+  find_package(PkgConfig)
+  pkg_check_modules(PC_LIBUSB libusb-1.0)
 
   FIND_PATH(LIBUSB_INCLUDE_DIR libusb.h
     PATHS ${PC_LIBUSB_INCLUDEDIR} ${PC_LIBUSB_INCLUDE_DIRS})