我正在尝试交叉编译libftdi。当我运行Cmake时,我得到:
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
LIBUSB_INCLUDE_DIR (ADVANCED)
我了解应该在libftdi根目录下的FindUSB1.cmake中设置LIBUSB_INCLUDE_DIR。但是,我不知道如何使FindUSB1.cmake查找已编译并放入/ opt / lib的libusb。这是默认文件:
# - Try to find the freetype library
# Once done this defines
#
# LIBUSB_FOUND - system has libusb
# LIBUSB_INCLUDE_DIR - the libusb include directory
# LIBUSB_LIBRARIES - Link these to use libusb
# Copyright (c) 2006, 2008 Laurent Montel, <montel@kde.org>
#
# Redistribution and use is allowed according to the terms of the BSD license.
# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
if (LIBUSB_INCLUDE_DIR AND LIBUSB_LIBRARIES)
# in cache already
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)
FIND_PATH(LIBUSB_INCLUDE_DIR libusb.h
PATHS ${PC_LIBUSB_INCLUDEDIR} ${PC_LIBUSB_INCLUDE_DIRS})
FIND_LIBRARY(LIBUSB_LIBRARIES NAMES usb-1.0
PATHS ${PC_LIBUSB_LIBDIR} ${PC_LIBUSB_LIBRARY_DIRS})
include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(LIBUSB DEFAULT_MSG LIBUSB_LIBRARIES LIBUSB_INCLUDE_DIR)
MARK_AS_ADVANCED(LIBUSB_INCLUDE_DIR LIBUSB_LIBRARIES)
endif (LIBUSB_INCLUDE_DIR AND LIBUSB_LIBRARIES)
在/ opt / lib中,有一个目录pkconfig。在此目录中,有一个libusb-1.0.pc文件,我想可能与该问题有关。那么我应该如何让Cmake查找/opt/lib/libsub-1.0?
最佳答案
不幸的是,默认的查找脚本不是很强大。如果该库不在find_library
搜索的one of the default directories中,则必须依靠 pkg-config
来告诉您该库的位置。
在(不太可能)事件也没有向pkg-config
注册该库的情况下,您别无选择,只能在调用查找脚本之前手动设置PC_LIBUSB_LIBDIR
和PC_LIBUSB_INCLUDEDIR
变量。可以从命令行(使用 -D
parameter)或在随附的CMake脚本中(使用 set
)完成此操作。
如果您愿意更改find脚本,请考虑将其他HINTS
添加到find调用中以使其更加灵活。例如,使用环境变量作为提示是一种非常流行的机制,该机制也适用于非Unix平台。
FIND_PATH(LIBUSB_INCLUDE_DIR libusb.h
HINTS $ENV{LIBUSB_ROOT}
PATHS ${PC_LIBUSB_INCLUDEDIR} ${PC_LIBUSB_INCLUDE_DIRS}
PATH_SUFFIXES include)
FIND_LIBRARY(LIBUSB_LIBRARIES NAMES usb-1.0
HINTS $ENV{LIBUSB_ROOT}
PATHS ${PC_LIBUSB_LIBDIR} ${PC_LIBUSB_LIBRARY_DIRS}
PATH_SUFFIXES lib)