# Ceres Solver - A fast non-linear least squares minimizer
# Copyright 2015 Google Inc. All rights reserved.
# http://ceres-solver.org/
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of Google Inc. nor the names of its contributors may be
# used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# Author: alexs.mac@gmail.com (Alex Stewart)
#
# FindGflags.cmake - Find Google gflags logging library.
#
# This module will attempt to find gflags, either via an exported CMake
# configuration (generated by gflags >= 2.1 which are built with CMake), or
# by performing a standard search for all gflags components. The order of
# precedence for these two methods of finding gflags is controlled by:
# GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION.
#
# This module defines the following variables:
#
# GFLAGS_FOUND: TRUE iff gflags is found.
# GFLAGS_INCLUDE_DIRS: Include directories for gflags.
# GFLAGS_LIBRARIES: Libraries required to link gflags.
# GFLAGS_NAMESPACE: The namespace in which gflags is defined. In versions of
# gflags < 2.1, this was google, for versions >= 2.1 it is
# by default gflags, although can be configured when building
# gflags to be something else (i.e. google for legacy
# compatibility).
# FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION: True iff the version of gflags
# found was built & installed /
# exported as a CMake package.
#
# The following variables control the behaviour of this module when an exported
# gflags CMake configuration is not found.
#
# GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION: TRUE/FALSE, iff TRUE then
# then prefer using an exported CMake configuration
# generated by gflags >= 2.1 over searching for the
# gflags components manually. Otherwise (FALSE)
# ignore any exported gflags CMake configurations and
# always perform a manual search for the components.
# Default: TRUE iff user does not define this variable
# before we are called, and does NOT specify either
# GFLAGS_INCLUDE_DIR_HINTS or GFLAGS_LIBRARY_DIR_HINTS
# otherwise FALSE.
# GFLAGS_INCLUDE_DIR_HINTS: List of additional directories in which to
# search for gflags includes, e.g: /timbuktu/include.
# GFLAGS_LIBRARY_DIR_HINTS: List of additional directories in which to
# search for gflags libraries, e.g: /timbuktu/lib.
#
# The following variables are also defined by this module, but in line with
# CMake recommended FindPackage() module style should NOT be referenced directly
# by callers (use the plural variables detailed above instead). These variables
# do however affect the behaviour of the module via FIND_[PATH/LIBRARY]() which
# are NOT re-called (i.e. search for library is not repeated) if these variables
# are set with valid values _in the CMake cache_. This means that if these
# variables are set directly in the cache, either by the user in the CMake GUI,
# or by the user passing -DVAR=VALUE directives to CMake when called (which
# explicitly defines a cache variable), then they will be used verbatim,
# bypassing the HINTS variables and other hard-coded search locations.
#
# GFLAGS_INCLUDE_DIR: Include directory for gflags, not including the
# include directory of any dependencies.
# GFLAGS_LIBRARY: gflags library, not including the libraries of any
# dependencies.
# Reset CALLERS_CMAKE_FIND_LIBRARY_PREFIXES to its value when FindGflags was
# invoked, necessary for MSVC.
macro(GFLAGS_RESET_FIND_LIBRARY_PREFIX)
if (MSVC AND CALLERS_CMAKE_FIND_LIBRARY_PREFIXES)
set(CMAKE_FIND_LIBRARY_PREFIXES "${CALLERS_CMAKE_FIND_LIBRARY_PREFIXES}")
endif()
endmacro(GFLAGS_RESET_FIND_LIBRARY_PREFIX)
# Called if we failed to find gflags or any of it's required dependencies,
# unsets all public (designed to be used externally) variables and reports
# error message at priority depending upon [REQUIRED/QUIET/<NONE>] argument.
macro(GFLAGS_REPORT_NOT_FOUND REASON_MSG)
unset(GFLAGS_FOUND)
unset(GFLAGS_INCLUDE_DIRS)
unset(GFLAGS_LIBRARIES)
# Do not use unset, as we want to keep GFLAGS_NAMESPACE in the cache,
# but simply clear its value.
set(GFLAGS_NAMESPACE "" CACHE STRING
"gflags namespace (google or gflags)" FORCE)
# Make results of search visible in the CMake GUI if gflags has not
# been found so that user does not have to toggle to advanced view.
mark_as_advanced(CLEAR GFLAGS_INCLUDE_DIR
GFLAGS_LIBRARY
GFLAGS_NAMESPACE)
gflags_reset_find_library_prefix()
# Note <package>_FIND_[REQUIRED/QUIETLY] variables defined by FindPackage()
# use the camelcase library name, not uppercase.
if (Gflags_FIND_QUIETLY)
message(STATUS "Failed to find gflags - " ${REASON_MSG} ${ARGN})
elseif (Gflags_FIND_REQUIRED)
message(FATAL_ERROR "Failed to find gflags - " ${REASON_MSG} ${ARGN})
else()
# Neither QUIETLY nor REQUIRED, use no priority which emits a message
# but continues configuration and allows generation.
message("-- Failed to find gflags - " ${REASON_MSG} ${ARGN})
endif ()
return()
endmacro(GFLAGS_REPORT_NOT_FOUND)
# Verify that all variable names passed as arguments are defined (can be empty
# but must be defined) or raise a fatal error.
macro(GFLAGS_CHECK_VARS_DEFINED)
foreach(CHECK_VAR ${ARGN})
if (NOT DEFINED ${CHECK_VAR})
message(FATAL_ERROR "Ceres Bug: ${CHECK_VAR} is not defined.")
endif()
endforeach()
endmacro(GFLAGS_CHECK_VARS_DEFINED)
# Use check_cxx_source_compiles() to compile trivial test programs to determine
# the gflags namespace. This works on all OSs except Windows. If using Visual
# Studio, it fails because msbuild forces check_cxx_source_compiles() to use
# CMAKE_BUILD_TYPE=Debug for the test project, which usually breaks detection
# because MSVC requires that the test project use the same build type as gflags,
# which would normally be built in Release.
#
# Defines: GFLAGS_NAMESPACE in the caller's scope with the detected namespace,
# which is blank (empty string, will test FALSE is CMake conditionals)
# if detection failed.
function(GFLAGS_CHECK_GFLAGS_NAMESPACE_USING_TRY_COMPILE)
# Verify that all required variables are defined.
gflags_check_vars_defined(
GFLAGS_INCLUDE_DIR GFLAGS_LIBRARY)
# Ensure that GFLAGS_NAMESPACE is always unset on completion unless
# we explicitly set if after having the correct namespace.
set(GFLAGS_NAMESPACE "" PARENT_SCOPE)
include(CheckCXXSourceCompiles)
# Setup include path & link library for gflags for CHECK_CXX_SOURCE_COMPILES.
set(CMAKE_REQUIRED_INCLUDES ${GFLAGS_INCLUDE_DIR})
set(CMAKE_REQUIRED_LIBRARIES ${GFLAGS_LIBRARY} ${GFLAGS_LINK_LIBRARIES})
# First try the (older) google namespace. Note that the output variable
# MUST be unique to the build type as otherwise the test is not repeated as
# it is assumed to have already been performed.
check_cxx_source_compiles(
"#include <gflags/gflags.h>
int main(int argc, char * argv[]) {
google::ParseCommandLineFlags(&argc, &argv, true);
return 0;
}"
GFLAGS_IN_GOOGLE_NAMESPACE)
if (GFLAGS_IN_GOOGLE_NAMESPACE)
set(GFLAGS_NAMESPACE google PARENT_SCOPE)
return()
endif()
# Try (newer) gflags namespace instead. Note that the output variable
# MUST be unique to the build type as otherwise the test is not repeated as
# it is assumed to have already been performed.
set(CMAKE_REQUIRED_INCLUDES ${GFLAGS_INCLUDE_DIR})
set(CMAKE_REQUIRED_LIBRARIES ${GFLAGS_LIBRARY} ${GFLAGS_LINK_LIBRARIES})
check_cxx_source_compiles(
"#include <gflags/gflags.h>
int main(int argc, char * argv[]) {
gflags::ParseCommandLineFlags(&argc, &argv, true);
return 0;
}"
GFLAGS_IN_GFLAGS_NAMESPACE)
if (GFLAGS_IN_GFLAGS_NAMESPACE)
set(GFLAGS_NAMESPACE gflags PARENT_SCOPE)
return()
endif (GFLAGS_IN_GFLAGS_NAMESPACE)
endfunction(GFLAGS_CHECK_GFLAGS_NAMESPACE_USING_TRY_COMPILE)
# Use regex on the gflags headers to attempt to determine the gflags namespace.
# Checks both gflags.h (contained namespace on versions < 2.1.2) and
# gflags_declare.h, which contains the namespace on versions >= 2.1.2.
# In general, this method should only be used when
# GFLAGS_CHECK_GFLAGS_NAMESPACE_USING_TRY_COMPILE() cannot be used, or has
# failed.
#
# Defines: GFLAGS_NAMESPACE in the caller's scope with the detected namespace,
# which is blank (empty string, will test FALSE is CMake conditionals)
# if detection failed.
function(GFLAGS_CHECK_GFLAGS_NAMESPACE_USING_REGEX)
# Verify that all required variables are defined.
gflags_check_vars_defined(GFLAGS_INCLUDE_DIR)
# Ensure that GFLAGS_NAMESPACE is always undefined on completion unless
# we explicitly set if after having the correct namespace.
set(GFLAGS_NAMESPACE "" PARENT_SCOPE)
# Scan gflags.h to identify what namespace gflags was built with. On
# versions of gflags < 2.1.2, gflags.h was configured with the namespace
# directly, on >= 2.1.2, gflags.h uses the GFLAGS_NAMESPACE #define which
# is defined in gflags_declare.h, we try each location in turn.
set(GFLAGS_HEADER_FILE ${GFLAGS_INCLUDE_DIR}/gflags/gflags.h)
if (NOT EXISTS ${GFLAGS_HEADER_FILE})
gflags_report_not_found(
"Could not find file: ${GFLAGS_HEADER_FILE} "
"containing namespace information in gflags install located at: "
"${GFLAGS_INCLUDE_DIR}.")
endif()
file(READ ${GFLAGS_HEADER_FILE} GFLAGS_HEADER_FILE_CONTENTS)
string(REGEX MATCH "namespace [A-Za-z]+"
GFLAGS_NAMESPACE "${GFLAGS_HEADER_FILE_CONTENTS}")
string(REGEX REPLACE "namespace ([A-Za-z]+)" "\\1"
GFLAGS_NAMESPACE "${GFLAGS_NAMESPACE}")
if (NOT GFLAGS_NAMESPACE)
gflags_report_not_found(
"Failed to extract gflags namespace from header file: "
"${GFLAGS_HEADER_FILE}.")
endif (NOT GFLAGS_NAMESPACE)
if (GFLAGS_NAMESPACE STREQUAL "google" OR
GFLAGS_NAMESPACE STREQUAL "gflags")
# Found valid gflags namespace from gflags.h.
set(GFLAGS_NAMESPACE "${GFLAGS_NAMESPACE}" PARENT_SCOPE)
return()
endif()
# Failed to find gflags namespace from gflags.h, gflags is likely a new
# version, check gflags_declare.h, which in newer versions (>= 2.1.2) contains
# the GFLAGS_NAMESPACE #define, which is then referenced in gflags.h.
set(GFLAGS_DECLARE_FILE ${GFLAGS_INCLUDE_DIR}/gflags/gflags_declare.h)
if (NOT EXISTS ${GFLAGS_DECLARE_FILE})
gflags_report_not_found(
"Could not find file: ${GFLAGS_DECLARE_FILE} "
"containing namespace information in gflags install located at: "
"${GFLAGS_INCLUDE_DIR}.")
endif()
file(READ ${GFLAGS_DECLARE_FILE} GFLAGS_DECLARE_FILE_CONTENTS)
string(REGEX MATCH "#define GFLAGS_NAMESPACE [A-Za-z]+"
GFLAGS_NAMESPACE "${GFLAGS_DECLARE_FILE_CONTENTS}")
string(REGEX REPLACE "#define GFLAGS_NAMESPACE ([A-Za-z]+)" "\\1"
GFLAGS_NAMESPACE "${GFLAGS_NAMESPACE}")
if (NOT GFLAGS_NAMESPACE)
gflags_report_not_found(
"Failed to extract gflags namespace from declare file: "
"${GFLAGS_DECLARE_FILE}.")
endif (NOT GFLAGS_NAMESPACE)
if (GFLAGS_NAMESPACE STREQUAL "google" OR
GFLAGS_NAMESPACE STREQUAL "gflags")
# Found valid gflags namespace from gflags.h.
set(GFLAGS_NAMESPACE "${GFLAGS_NAMESPACE}" PARENT_SCOPE)
return()
endif()
endfunction(GFLAGS_CHECK_GFLAGS_NAMESPACE_USING_REGEX)
# Protect against any alternative find_package scripts for this library having
# been called previously (in a client project) which set GFLAGS_FOUND, but not
# the other variables we require / set here which could cause the search logic
# here to fail.
unset(GFLAGS_FOUND)
# -----------------------------------------------------------------
# By default, if the user has expressed no preference for using an exported
# gflags CMake configuration over performing a search for the installed
# components, and has not specified any hints for the search locations, then
# prefer a gflags exported configuration if available.
if (NOT DEFINED GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION
AND NOT GFLAGS_INCLUDE_DIR_HINTS
AND NOT GFLAGS_LIBRARY_DIR_HINTS)
message(STATUS "No preference for use of exported gflags CMake configuration "
"set, and no hints for include/library directories provided. "
"Defaulting to preferring an installed/exported gflags CMake configuration "
"if available.")
set(GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION TRUE)
endif()
if (GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION)
# Try to find an exported CMake configuration for gflags, as generated by
# gflags versions >= 2.1.
#
# We search twice, s/t we can invert the ordering of precedence used by
# find_package() for exported package build directories, and installed
# packages (found via CMAKE_SYSTEM_PREFIX_PATH), listed as items 6) and 7)
# respectively in [1].
#
# By default, exported build directories are (in theory) detected first, and
# this is usually the case on Windows. However, on OS X & Linux, the install
# path (/usr/local) is typically present in the PATH environment variable
# which is checked in item 4) in [1] (i.e. before both of the above, unless
# NO_SYSTEM_ENVIRONMENT_PATH is passed). As such on those OSs installed
# packages are usually detected in preference to exported package build
# directories.
#
# To ensure a more consistent response across all OSs, and as users usually
# want to prefer an installed version of a package over a locally built one
# where both exist (esp. as the exported build directory might be removed
# after installation), we first search with NO_CMAKE_PACKAGE_REGISTRY which
# means any build directories exported by the user are ignored, and thus
# installed directories are preferred. If this fails to find the package
# we then research again, but without NO_CMAKE_PACKAGE_REGISTRY, so any
# exported build directories will now be detected.
#
# To prevent confusion on Windows, we also pass NO_CMAKE_BUILDS_PATH (which
# is item 5) in [1]), to not preferentially use projects that were built
# recently with the CMake GUI to ensure that we always prefer an installed
# version if available.
#
# [1] http://www.cmake.org/cmake/help/v2.8.11/cmake.html#command:find_package
find_package(gflags QUIET
NO_MODULE
NO_CMAKE_PACKAGE_REGISTRY
NO_CMAKE_BUILDS_PATH)
if (gflags_FOUND)
message(STATUS "Found installed version of gflags: ${gflags_DIR}")
else(gflags_FOUND)
# Failed to find an installed version of gflags, repeat search allowing
# exported build directories.
message(STATUS "Failed to find installed gflags CMake configuration, "
"searching for gflags build directories exported with CMake.")
# Again pass NO_CMAKE_BUILDS_PATH, as we know that gflags is exported and
# do not want to treat projects built with the CMake GUI preferentially.
find_package(gflags QUIET
NO_MODULE
NO_CMAKE_BUILDS_PATH)
if (gflags_FOUND)
message(STATUS "Found exported gflags build directory: ${gflags_DIR}")
endif(gflags_FOUND)
endif(gflags_FOUND)
set(FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION ${gflags_FOUND})
# gflags v2.1 - 2.1.2 shipped with a bug in their gflags-config.cmake [1]
# whereby gflags_LIBRARIES = "gflags", but there was no imported target
# called "gflags", they were called: gflags[_nothreads]-[static/shared].
# As this causes linker errors when gflags is not installed in a location
# on the current library paths, detect if this problem is present and
# fix it.
#
# [1] https://github.com/gflags/gflags/issues/110
if (gflags_FOUND)
# NOTE: This is not written as additional conditions in the outer
# if (gflags_FOUND) as the NOT TARGET "${gflags_LIBRARIES}"
# condition causes problems if gflags is not found.
if (${gflags_VERSION} VERSION_LESS 2.1.3 AND
NOT TARGET "${gflags_LIBRARIES}")
message(STATUS "Detected broken gflags install in: ${gflags_DIR}, "
"version: ${gflags_VERSION} <= 2.1.2 which defines gflags_LIBRARIES = "
"${gflags_LIBRARIES} which is not an imported CMake target, see: "
"https://github.com/gflags/gflags/issues/110. Attempting to fix by "
"detecting correct gflags target.")
# Ordering here expresses preference for detection, specifically we do not
# want to use the _nothreads variants if the full library is available.
list(APPEND CHECK_GFLAGS_IMPORTED_TARGET_NAMES
gflags-shared gflags-static
gflags_nothreads-shared gflags_nothreads-static)
foreach(CHECK_GFLAGS_TARGET ${CHECK_GFLAGS_IMPORTED_TARGET_NAMES})
if (TARGET ${CHECK_GFLAGS_TARGET})
message(STATUS "Found valid gflags target: ${CHECK_GFLAGS_TARGET}, "
"updating gflags_LIBRARIES.")
set(gflags_LIBRARIES ${CHECK_GFLAGS_TARGET})
break()
endif()
endforeach()
if (NOT TARGET ${gflags_LIBRARIES})
message(STATUS "Failed to fix detected broken gflags install in: "
"${gflags_DIR}, version: ${gflags_VERSION} <= 2.1.2, none of the "
"imported targets for gflags: ${CHECK_GFLAGS_IMPORTED_TARGET_NAMES} "
"are defined. Will continue with a manual search for gflags "
"components. We recommend you build/install a version of gflags > "
"2.1.2 (or master).")
set(FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION FALSE)
endif()
endif()
endif()
if (FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION)
message(STATUS "Detected gflags version: ${gflags_VERSION}")
set(GFLAGS_FOUND ${gflags_FOUND})
set(GFLAGS_INCLUDE_DIR "/usr/include")
set(GFLAGS_LIBRARY ${gflags_LIBRARIES})
# gflags does not export the namespace in their CMake configuration, so
# use our function to determine what it should be, as it can be either
# gflags or google dependent upon version & configuration.
#
# NOTE: We use the regex method to determine the namespace here, as
# check_cxx_source_compiles() will not use imported targets, which
# is what gflags will be in this case.
gflags_check_gflags_namespace_using_regex()
if (NOT GFLAGS_NAMESPACE)
gflags_report_not_found(
"Failed to determine gflags namespace using regex for gflags "
"version: ${gflags_VERSION} exported here: ${gflags_DIR} using CMake.")
endif (NOT GFLAGS_NAMESPACE)
else (FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION)
message(STATUS "Failed to find an installed/exported CMake configuration "
"for gflags, will perform search for installed gflags components.")
endif (FOUND_INSTALLED_GFLAGS_CMAKE_CONFIGURATION)
endif(GFLAGS_PREFER_EXPORTED_GFLAGS_CMAKE_CONFIGURATION)
if (NOT GFLAGS_FOUND)
# Either failed to find an exported gflags CMake configuration, or user
# told us not to use one. Perform a manual search for all gflags components.
# Handle possible presence of lib prefix for libraries on MSVC, see
# also GFLAGS_RESET_FIND_LIBRARY_PREFIX().
if (MSVC)
# Preserve the caller's original values for CMAKE_FIND_LIBRARY_PREFIXES
# s/t we can set it back before returning.
set(CALLERS_CMAKE_FIND_LIBRARY_PREFIXES "${CMAKE_FIND_LIBRARY_PREFIXES}")
# The empty string in this list is important, it represents the case when
# the libraries have no prefix (shared libraries / DLLs).
set(CMAKE_FIND_LIBRARY_PREFIXES "lib" "" "${CMAKE_FIND_LIBRARY_PREFIXES}")
endif (MSVC)
# Search user-installed locations first, so that we prefer user installs
# to system installs where both exist.
list(APPEND GFLAGS_CHECK_INCLUDE_DIRS
/usr/local/include
/usr/local/homebrew/include # Mac OS X
/opt/local/var/macports/software # Mac OS X.
/opt/local/include
/usr/include)
list(APPEND GFLAGS_CHECK_PATH_SUFFIXES
gflags/include # Windows (for C:/Program Files prefix).
gflags/Include ) # Windows (for C:/Program Files prefix).
list(APPEND GFLAGS_CHECK_LIBRARY_DIRS
/usr/local/lib
/usr/local/homebrew/lib # Mac OS X.
/opt/local/lib
/usr/lib)
list(APPEND GFLAGS_CHECK_LIBRARY_SUFFIXES
gflags/lib # Windows (for C:/Program Files prefix).
gflags/Lib ) # Windows (for C:/Program Files prefix).
# Search supplied hint directories first if supplied.
find_path(GFLAGS_INCLUDE_DIR
NAMES gflags/gflags.h
HINTS ${GFLAGS_INCLUDE_DIR_HINTS}
PATHS ${GFLAGS_CHECK_INCLUDE_DIRS}
PATH_SUFFIXES ${GFLAGS_CHECK_PATH_SUFFIXES})
if (NOT GFLAGS_INCLUDE_DIR OR
NOT EXISTS ${GFLAGS_INCLUDE_DIR})
gflags_report_not_found(
"Could not find gflags include directory, set GFLAGS_INCLUDE_DIR "
"to directory containing gflags/gflags.h")
endif (NOT GFLAGS_INCLUDE_DIR OR
NOT EXISTS ${GFLAGS_INCLUDE_DIR})
find_library(GFLAGS_LIBRARY NAMES gflags
HINTS ${GFLAGS_LIBRARY_DIR_HINTS}
PATHS ${GFLAGS_CHECK_LIBRARY_DIRS}
PATH_SUFFIXES ${GFLAGS_CHECK_LIBRARY_SUFFIXES})
if (NOT GFLAGS_LIBRARY OR
NOT EXISTS ${GFLAGS_LIBRARY})
gflags_report_not_found(
"Could not find gflags library, set GFLAGS_LIBRARY "
"to full path to libgflags.")
endif (NOT GFLAGS_LIBRARY OR
NOT EXISTS ${GFLAGS_LIBRARY})
# gflags typically requires a threading library (which is OS dependent), note
# that this defines the CMAKE_THREAD_LIBS_INIT variable. If we are able to
# detect threads, we assume that gflags requires it.
find_package(Threads QUIET)
set(GFLAGS_LINK_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
# On Windows (including MinGW), the Shlwapi library is used by gflags if
# available.
if (WIN32)
include(CheckIncludeFileCXX)
check_include_file_cxx("shlwapi.h" HAVE_SHLWAPI)
if (HAVE_SHLWAPI)
list(APPEND GFLAGS_LINK_LIBRARIES shlwapi.lib)
endif(HAVE_SHLWAPI)
endif (WIN32)
# Mark internally as found, then verify. GFLAGS_REPORT_NOT_FOUND() unsets
# if called.
set(GFLAGS_FOUND TRUE)
# Identify what namespace gflags was built with.
if (GFLAGS_INCLUDE_DIR AND NOT GFLAGS_NAMESPACE)
# To handle Windows peculiarities / CMake bugs on MSVC we try two approaches
# to detect the gflags namespace:
#
# 1) Try to use check_cxx_source_compiles() to compile a trivial program
# with the two choices for the gflags namespace.
#
# 2) [In the event 1) fails] Use regex on the gflags headers to try to
# determine the gflags namespace. Whilst this is less robust than 1),
# it does avoid any interaction with msbuild.
gflags_check_gflags_namespace_using_try_compile()
if (NOT GFLAGS_NAMESPACE)
# Failed to determine gflags namespace using check_cxx_source_compiles()
# method, try and obtain it using regex on the gflags headers instead.
message(STATUS "Failed to find gflags namespace using using "
"check_cxx_source_compiles(), trying namespace regex instead, "
"this is expected on Windows.")
gflags_check_gflags_namespace_using_regex()
if (NOT GFLAGS_NAMESPACE)
gflags_report_not_found(
"Failed to determine gflags namespace either by "
"check_cxx_source_compiles(), or namespace regex.")
endif (NOT GFLAGS_NAMESPACE)
endif (NOT GFLAGS_NAMESPACE)
endif (GFLAGS_INCLUDE_DIR AND NOT GFLAGS_NAMESPACE)
# Make the GFLAGS_NAMESPACE a cache variable s/t the user can view it, and could
# overwrite it in the CMake GUI.
set(GFLAGS_NAMESPACE "${GFLAGS_NAMESPACE}" CACHE STRING
"gflags namespace (google or gflags)" FORCE)
# gflags does not seem to provide any record of the version in its
# source tree, thus cannot extract version.
# Catch case when caller has set GFLAGS_NAMESPACE in the cache / GUI
# with an invalid value.
if (GFLAGS_NAMESPACE AND
NOT GFLAGS_NAMESPACE STREQUAL "google" AND
NOT GFLAGS_NAMESPACE STREQUAL "gflags")
gflags_report_not_found(
"Caller defined GFLAGS_NAMESPACE:"
" ${GFLAGS_NAMESPACE} is not valid, not google or gflags.")
endif ()
# Catch case when caller has set GFLAGS_INCLUDE_DIR in the cache / GUI and
# thus FIND_[PATH/LIBRARY] are not called, but specified locations are
# invalid, otherwise we would report the library as found.
if (GFLAGS_INCLUDE_DIR AND
NOT EXISTS ${GFLAGS_INCLUDE_DIR}/gflags/gflags.h)
gflags_report_not_found(
"Caller defined GFLAGS_INCLUDE_DIR:"
" ${GFLAGS_INCLUDE_DIR} does not contain gflags/gflags.h header.")
endif (GFLAGS_INCLUDE_DIR AND
NOT EXISTS ${GFLAGS_INCLUDE_DIR}/gflags/gflags.h)
# TODO: This regex for gflags library is pretty primitive, we use lowercase
# for comparison to handle Windows using CamelCase library names, could
# this check be better?
string(TOLOWER "${GFLAGS_LIBRARY}" LOWERCASE_GFLAGS_LIBRARY)
if (GFLAGS_LIBRARY AND
NOT "${LOWERCASE_GFLAGS_LIBRARY}" MATCHES ".*gflags[^/]*")
gflags_report_not_found(
"Caller defined GFLAGS_LIBRARY: "
"${GFLAGS_LIBRARY} does not match gflags.")
endif (GFLAGS_LIBRARY AND
NOT "${LOWERCASE_GFLAGS_LIBRARY}" MATCHES ".*gflags[^/]*")
gflags_reset_find_library_prefix()
endif(NOT GFLAGS_FOUND)
# Set standard CMake FindPackage variables if found.
if (GFLAGS_FOUND)
set(GFLAGS_INCLUDE_DIRS ${GFLAGS_INCLUDE_DIR})
set(GFLAGS_LIBRARIES ${GFLAGS_LIBRARY} ${GFLAGS_LINK_LIBRARIES})
endif (GFLAGS_FOUND)
# Handle REQUIRED / QUIET optional arguments.
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(Gflags DEFAULT_MSG
GFLAGS_INCLUDE_DIRS GFLAGS_LIBRARIES GFLAGS_NAMESPACE)
# Only mark internal variables as advanced if we found gflags, otherwise
# leave them visible in the standard GUI for the user to set manually.
if (GFLAGS_FOUND)
mark_as_advanced(FORCE GFLAGS_INCLUDE_DIR
GFLAGS_LIBRARY
GFLAGS_NAMESPACE
gflags_DIR) # Autogenerated by find_package(gflags)
endif (GFLAGS_FOUND)