CMake/Modules/FindCurses.cmake
Brad King c4275592a8 Modules: Include builtin FindPackageHandleStandardArgs directly
The FindPackageHandleStandardArgs module was originally created outside
of CMake.  It was added for CMake 2.6.0 by commit e118a627 (add a macro
FIND_PACKAGE_HANDLE_STANDARD_ARGS..., 2007-07-18).  However, it also
proliferated into a number of other projects that at the time required
only CMake 2.4 and thus could not depend on CMake to provide the module.
CMake's own find modules started using the module in commit b5f656e0
(use the new FIND_PACKAGE_HANDLE_STANDARD_ARGS in some of the FindXXX
modules..., 2007-07-18).

Then commit d358cf5c (add 2nd, more powerful mode to
find_package_handle_standard_args, 2010-07-29) added a new feature to
the interface of the module that was fully optional and backward
compatible with all existing users of the module.  Later commit 5f183caa
(FindZLIB: use the FPHSA version mode, 2010-08-04) and others shortly
thereafter started using the new interface in CMake's own find modules.
This change was also backward compatible because it was only an
implementation detail within each module.

Unforutnately these changes introduced a problem for projects that still
have an old copy of FindPackageHandleStandardArgs in CMAKE_MODULE_PATH.
When any such project uses one of CMake's builtin find modules the line

  include(FindPackageHandleStandardArgs)

loads the copy from the project which does not have the new interface!
Then the including find module tries to use the new interface with the
old module and fails.

Whether this breakage can be considered a backward incompatible change
in CMake is debatable.  The situation is analagous to copying a standard
library header from one version of a compiler into a project and then
observing problems when the next version of the compiler reports errors
in its other headers that depend on its new version of the original
header.  Nevertheless it is a change to CMake that causes problems for
projects that worked with previous versions.

This problem was discovered during the 2.8.3 release candidate cycle.
It is an instance of a more general problem with projects that provide
their own versions of CMake modules when other CMake modules depend on
them.  At the time we resolved this instance of the problem with commit
b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake
everywhere, 2010-09-28) for the 2.8.3 release.

In order to address the more general problem we introduced policy
CMP0017 in commit db44848f (Prefer files from CMAKE_ROOT when including
from CMAKE_ROOT, 2010-11-17).  That change was followed by commit
ce28737c (Remove usage of CMAKE_CURRENT_LIST_DIR now that we have
CMP0017, 2010-12-20) which reverted the original workaround in favor of
using the policy.  However, existing project releases do not set the
policy behavior to NEW and therefore still exhibit the problem.

We introduced in commit a364daf1 (Allow users to specify defaults for
unset policies, 2011-01-03) an option for users to build existing
projects by adding -DCMAKE_POLICY_DEFAULT_CMP0017=NEW to the command
line.  Unfortunately this solution still does not allow such projects to
build out of the box, and there is no good way to suggest the use of the
new option.

The only remaining solution to keep existing projects that exhibit this
problem building is to restore the change originally made in commit
b0118402 (Use absolute path to FindPackageHandleStandardArgs.cmake
everywhere, 2010-09-28).  This also avoids policy CMP0017 warnings for
this particular instance of the problem the policy addresses.
2011-01-20 10:56:49 -05:00

177 lines
7.0 KiB
CMake

# - Find the curses include file and library
#
# CURSES_FOUND - system has Curses
# CURSES_INCLUDE_DIR - the Curses include directory
# CURSES_LIBRARIES - The libraries needed to use Curses
# CURSES_HAVE_CURSES_H - true if curses.h is available
# CURSES_HAVE_NCURSES_H - true if ncurses.h is available
# CURSES_HAVE_NCURSES_NCURSES_H - true if ncurses/ncurses.h is available
# CURSES_HAVE_NCURSES_CURSES_H - true if ncurses/curses.h is available
# CURSES_LIBRARY - set for backwards compatibility with 2.4 CMake
#
# Set CURSES_NEED_NCURSES to TRUE before the FIND_PACKAGE() command if NCurses
# functionality is required.
#=============================================================================
# Copyright 2001-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
FIND_LIBRARY(CURSES_CURSES_LIBRARY NAMES curses )
FIND_LIBRARY(CURSES_NCURSES_LIBRARY NAMES ncurses )
SET(CURSES_USE_NCURSES FALSE)
IF(CURSES_NCURSES_LIBRARY AND NOT CURSES_CURSES_LIBRARY)
SET(CURSES_USE_NCURSES TRUE)
ENDIF(CURSES_NCURSES_LIBRARY AND NOT CURSES_CURSES_LIBRARY)
# http://cygwin.com/ml/cygwin-announce/2010-01/msg00002.html
# cygwin ncurses stopped providing curses.h symlinks see above
# message. Cygwin is an ncurses package, so force ncurses on
# cygwin if the curses.h is missing
IF(CYGWIN)
IF(NOT EXISTS /usr/include/curses.h)
SET(CURSES_USE_NCURSES TRUE)
ENDIF()
ENDIF()
# Not sure the logic is correct here.
# If NCurses is required, use the function wsyncup() to check if the library
# has NCurses functionality (at least this is where it breaks on NetBSD).
# If wsyncup is in curses, use this one.
# If not, try to find ncurses and check if this has the symbol.
# Once the ncurses library is found, search the ncurses.h header first, but
# some web pages also say that even with ncurses there is not always a ncurses.h:
# http://osdir.com/ml/gnome.apps.mc.devel/2002-06/msg00029.html
# So at first try ncurses.h, if not found, try to find curses.h under the same
# prefix as the library was found, if still not found, try curses.h with the
# default search paths.
IF(CURSES_CURSES_LIBRARY AND CURSES_NEED_NCURSES)
INCLUDE(CheckLibraryExists)
CHECK_LIBRARY_EXISTS("${CURSES_CURSES_LIBRARY}"
wsyncup "" CURSES_CURSES_HAS_WSYNCUP)
IF(CURSES_NCURSES_LIBRARY AND NOT CURSES_CURSES_HAS_WSYNCUP)
CHECK_LIBRARY_EXISTS("${CURSES_NCURSES_LIBRARY}"
wsyncup "" CURSES_NCURSES_HAS_WSYNCUP)
IF( CURSES_NCURSES_HAS_WSYNCUP)
SET(CURSES_USE_NCURSES TRUE)
ENDIF( CURSES_NCURSES_HAS_WSYNCUP)
ENDIF(CURSES_NCURSES_LIBRARY AND NOT CURSES_CURSES_HAS_WSYNCUP)
ENDIF(CURSES_CURSES_LIBRARY AND CURSES_NEED_NCURSES)
IF(NOT CURSES_USE_NCURSES)
FIND_FILE(CURSES_HAVE_CURSES_H curses.h )
FIND_PATH(CURSES_CURSES_H_PATH curses.h )
GET_FILENAME_COMPONENT(_cursesLibDir "${CURSES_CURSES_LIBRARY}" PATH)
GET_FILENAME_COMPONENT(_cursesParentDir "${_cursesLibDir}" PATH)
# for compatibility with older FindCurses.cmake this has to be in the cache
# FORCE must not be used since this would break builds which preload a cache wqith these variables set
SET(CURSES_INCLUDE_PATH "${CURSES_CURSES_H_PATH}"
CACHE FILEPATH "The curses include path")
SET(CURSES_LIBRARY "${CURSES_CURSES_LIBRARY}"
CACHE FILEPATH "The curses library")
ELSE(NOT CURSES_USE_NCURSES)
# we need to find ncurses
GET_FILENAME_COMPONENT(_cursesLibDir "${CURSES_NCURSES_LIBRARY}" PATH)
GET_FILENAME_COMPONENT(_cursesParentDir "${_cursesLibDir}" PATH)
FIND_FILE(CURSES_HAVE_NCURSES_H ncurses.h)
FIND_FILE(CURSES_HAVE_NCURSES_NCURSES_H ncurses/ncurses.h)
FIND_FILE(CURSES_HAVE_NCURSES_CURSES_H ncurses/curses.h)
FIND_FILE(CURSES_HAVE_CURSES_H curses.h
HINTS "${_cursesParentDir}/include")
FIND_PATH(CURSES_NCURSES_INCLUDE_PATH ncurses.h ncurses/ncurses.h
ncurses/curses.h)
FIND_PATH(CURSES_NCURSES_INCLUDE_PATH curses.h
HINTS "${_cursesParentDir}/include")
# for compatibility with older FindCurses.cmake this has to be in the cache
# FORCE must not be used since this would break builds which preload
# however if the value of the variable has NOTFOUND in it, then
# it is OK to force, and we need to force in order to have it work.
# a cache wqith these variables set
# only put ncurses include and library into
# variables if they are found
IF(NOT CURSES_NCURSES_INCLUDE_PATH AND CURSES_HAVE_NCURSES_NCURSES_H)
GET_FILENAME_COMPONENT(CURSES_NCURSES_INCLUDE_PATH
"${CURSES_HAVE_NCURSES_NCURSES_H}" PATH)
ENDIF(NOT CURSES_NCURSES_INCLUDE_PATH AND CURSES_HAVE_NCURSES_NCURSES_H)
IF(CURSES_NCURSES_INCLUDE_PATH AND CURSES_NCURSES_LIBRARY)
SET( FORCE_IT )
IF(CURSES_INCLUDE_PATH MATCHES NOTFOUND)
SET(FORCE_IT FORCE)
ENDIF(CURSES_INCLUDE_PATH MATCHES NOTFOUND)
SET(CURSES_INCLUDE_PATH "${CURSES_NCURSES_INCLUDE_PATH}"
CACHE FILEPATH "The curses include path" ${FORCE_IT})
SET( FORCE_IT)
IF(CURSES_LIBRARY MATCHES NOTFOUND)
SET(FORCE_IT FORCE)
ENDIF(CURSES_LIBRARY MATCHES NOTFOUND)
SET(CURSES_LIBRARY "${CURSES_NCURSES_LIBRARY}"
CACHE FILEPATH "The curses library" ${FORCE_IT})
ENDIF(CURSES_NCURSES_INCLUDE_PATH AND CURSES_NCURSES_LIBRARY)
ENDIF(NOT CURSES_USE_NCURSES)
FIND_LIBRARY(CURSES_EXTRA_LIBRARY cur_colr HINTS "${_cursesLibDir}")
FIND_LIBRARY(CURSES_EXTRA_LIBRARY cur_colr )
FIND_LIBRARY(CURSES_FORM_LIBRARY form HINTS "${_cursesLibDir}")
FIND_LIBRARY(CURSES_FORM_LIBRARY form )
# for compatibility with older FindCurses.cmake this has to be in the cache
# FORCE must not be used since this would break builds which preload a cache
# qith these variables set
SET(FORM_LIBRARY "${CURSES_FORM_LIBRARY}"
CACHE FILEPATH "The curses form library")
# Need to provide the *_LIBRARIES
SET(CURSES_LIBRARIES ${CURSES_LIBRARY})
IF(CURSES_EXTRA_LIBRARY)
SET(CURSES_LIBRARIES ${CURSES_LIBRARIES} ${CURSES_EXTRA_LIBRARY})
ENDIF(CURSES_EXTRA_LIBRARY)
IF(CURSES_FORM_LIBRARY)
SET(CURSES_LIBRARIES ${CURSES_LIBRARIES} ${CURSES_FORM_LIBRARY})
ENDIF(CURSES_FORM_LIBRARY)
# Proper name is *_INCLUDE_DIR
SET(CURSES_INCLUDE_DIR ${CURSES_INCLUDE_PATH})
# handle the QUIETLY and REQUIRED arguments and set CURSES_FOUND to TRUE if
# all listed variables are TRUE
INCLUDE(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(Curses DEFAULT_MSG
CURSES_LIBRARY CURSES_INCLUDE_PATH)
MARK_AS_ADVANCED(
CURSES_INCLUDE_PATH
CURSES_LIBRARY
CURSES_CURSES_INCLUDE_PATH
CURSES_CURSES_LIBRARY
CURSES_NCURSES_INCLUDE_PATH
CURSES_NCURSES_LIBRARY
CURSES_EXTRA_LIBRARY
FORM_LIBRARY
CURSES_LIBRARIES
CURSES_INCLUDE_DIR
CURSES_CURSES_HAS_WSYNCUP
CURSES_NCURSES_HAS_WSYNCUP
)