1# - Find python libraries
2# This module finds the libraries corresponding to the Python interpreter
3# FindPythonInterp provides.
4# This code sets the following variables:
5#
6#  PYTHONLIBS_FOUND           - have the Python libs been found
7#  PYTHON_PREFIX              - path to the Python installation
8#  PYTHON_LIBRARIES           - path to the python library
9#  PYTHON_INCLUDE_DIRS        - path to where Python.h is found
10#  PYTHON_MODULE_EXTENSION    - lib extension, e.g. '.so' or '.pyd'
11#  PYTHON_MODULE_PREFIX       - lib name prefix: usually an empty string
12#  PYTHON_SITE_PACKAGES       - path to installation site-packages
13#  PYTHON_IS_DEBUG            - whether the Python interpreter is a debug build
14#
15# Thanks to talljimbo for the patch adding the 'LDVERSION' config
16# variable usage.
17
18#=============================================================================
19# Copyright 2001-2009 Kitware, Inc.
20# Copyright 2012 Continuum Analytics, Inc.
21#
22# All rights reserved.
23#
24# Redistribution and use in source and binary forms, with or without
25# modification, are permitted provided that the following conditions
26# are met:
27#
28# * Redistributions of source code must retain the above copyright
29# notice, this list of conditions and the following disclaimer.
30#
31# * Redistributions in binary form must reproduce the above copyright
32# notice, this list of conditions and the following disclaimer in the
33# documentation and/or other materials provided with the distribution.
34#
35# * Neither the names of Kitware, Inc., the Insight Software Consortium,
36# nor the names of their contributors may be used to endorse or promote
37# products derived from this software without specific prior written
38# permission.
39#
40# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
41# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
42# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
43# # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
44# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
46# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
47# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
48# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
49# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
50# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51#=============================================================================
52
53# Checking for the extension makes sure that `LibsNew` was found and not just `Libs`.
54if(PYTHONLIBS_FOUND AND PYTHON_MODULE_EXTENSION)
55    return()
56endif()
57
58# Use the Python interpreter to find the libs.
59if(PythonLibsNew_FIND_REQUIRED)
60    find_package(PythonInterp ${PythonLibsNew_FIND_VERSION} REQUIRED)
61else()
62    find_package(PythonInterp ${PythonLibsNew_FIND_VERSION})
63endif()
64
65if(NOT PYTHONINTERP_FOUND)
66    set(PYTHONLIBS_FOUND FALSE)
67    set(PythonLibsNew_FOUND FALSE)
68    return()
69endif()
70
71# According to http://stackoverflow.com/questions/646518/python-how-to-detect-debug-interpreter
72# testing whether sys has the gettotalrefcount function is a reliable, cross-platform
73# way to detect a CPython debug interpreter.
74#
75# The library suffix is from the config var LDVERSION sometimes, otherwise
76# VERSION. VERSION will typically be like "2.7" on unix, and "27" on windows.
77execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
78    "from distutils import sysconfig as s;import sys;import struct;
79print('.'.join(str(v) for v in sys.version_info));
80print(sys.prefix);
81print(s.get_python_inc(plat_specific=True));
82print(s.get_python_lib(plat_specific=True));
83print(s.get_config_var('SO'));
84print(hasattr(sys, 'gettotalrefcount')+0);
85print(struct.calcsize('@P'));
86print(s.get_config_var('LDVERSION') or s.get_config_var('VERSION'));
87print(s.get_config_var('LIBDIR') or '');
88print(s.get_config_var('MULTIARCH') or '');
89"
90    RESULT_VARIABLE _PYTHON_SUCCESS
91    OUTPUT_VARIABLE _PYTHON_VALUES
92    ERROR_VARIABLE _PYTHON_ERROR_VALUE)
93
94if(NOT _PYTHON_SUCCESS MATCHES 0)
95    if(PythonLibsNew_FIND_REQUIRED)
96        message(FATAL_ERROR
97            "Python config failure:\n${_PYTHON_ERROR_VALUE}")
98    endif()
99    set(PYTHONLIBS_FOUND FALSE)
100    set(PythonLibsNew_FOUND FALSE)
101    return()
102endif()
103
104# Convert the process output into a list
105if(WIN32)
106    string(REGEX REPLACE "\\\\" "/" _PYTHON_VALUES ${_PYTHON_VALUES})
107endif()
108string(REGEX REPLACE ";" "\\\\;" _PYTHON_VALUES ${_PYTHON_VALUES})
109string(REGEX REPLACE "\n" ";" _PYTHON_VALUES ${_PYTHON_VALUES})
110list(GET _PYTHON_VALUES 0 _PYTHON_VERSION_LIST)
111list(GET _PYTHON_VALUES 1 PYTHON_PREFIX)
112list(GET _PYTHON_VALUES 2 PYTHON_INCLUDE_DIR)
113list(GET _PYTHON_VALUES 3 PYTHON_SITE_PACKAGES)
114list(GET _PYTHON_VALUES 4 PYTHON_MODULE_EXTENSION)
115list(GET _PYTHON_VALUES 5 PYTHON_IS_DEBUG)
116list(GET _PYTHON_VALUES 6 PYTHON_SIZEOF_VOID_P)
117list(GET _PYTHON_VALUES 7 PYTHON_LIBRARY_SUFFIX)
118list(GET _PYTHON_VALUES 8 PYTHON_LIBDIR)
119list(GET _PYTHON_VALUES 9 PYTHON_MULTIARCH)
120
121# Make sure the Python has the same pointer-size as the chosen compiler
122# Skip if CMAKE_SIZEOF_VOID_P is not defined
123if(CMAKE_SIZEOF_VOID_P AND (NOT "${PYTHON_SIZEOF_VOID_P}" STREQUAL "${CMAKE_SIZEOF_VOID_P}"))
124    if(PythonLibsNew_FIND_REQUIRED)
125        math(EXPR _PYTHON_BITS "${PYTHON_SIZEOF_VOID_P} * 8")
126        math(EXPR _CMAKE_BITS "${CMAKE_SIZEOF_VOID_P} * 8")
127        message(FATAL_ERROR
128            "Python config failure: Python is ${_PYTHON_BITS}-bit, "
129            "chosen compiler is  ${_CMAKE_BITS}-bit")
130    endif()
131    set(PYTHONLIBS_FOUND FALSE)
132    set(PythonLibsNew_FOUND FALSE)
133    return()
134endif()
135
136# The built-in FindPython didn't always give the version numbers
137string(REGEX REPLACE "\\." ";" _PYTHON_VERSION_LIST ${_PYTHON_VERSION_LIST})
138list(GET _PYTHON_VERSION_LIST 0 PYTHON_VERSION_MAJOR)
139list(GET _PYTHON_VERSION_LIST 1 PYTHON_VERSION_MINOR)
140list(GET _PYTHON_VERSION_LIST 2 PYTHON_VERSION_PATCH)
141
142# Make sure all directory separators are '/'
143string(REGEX REPLACE "\\\\" "/" PYTHON_PREFIX ${PYTHON_PREFIX})
144string(REGEX REPLACE "\\\\" "/" PYTHON_INCLUDE_DIR ${PYTHON_INCLUDE_DIR})
145string(REGEX REPLACE "\\\\" "/" PYTHON_SITE_PACKAGES ${PYTHON_SITE_PACKAGES})
146
147if(CMAKE_HOST_WIN32 AND NOT (MSYS OR MINGW))
148    set(PYTHON_LIBRARY
149        "${PYTHON_PREFIX}/libs/Python${PYTHON_LIBRARY_SUFFIX}.lib")
150
151    # when run in a venv, PYTHON_PREFIX points to it. But the libraries remain in the
152    # original python installation. They may be found relative to PYTHON_INCLUDE_DIR.
153    if(NOT EXISTS "${PYTHON_LIBRARY}")
154        get_filename_component(_PYTHON_ROOT ${PYTHON_INCLUDE_DIR} DIRECTORY)
155        set(PYTHON_LIBRARY
156            "${_PYTHON_ROOT}/libs/Python${PYTHON_LIBRARY_SUFFIX}.lib")
157    endif()
158
159    # raise an error if the python libs are still not found.
160    if(NOT EXISTS "${PYTHON_LIBRARY}")
161        message(FATAL_ERROR "Python libraries not found")
162    endif()
163
164else()
165    if(PYTHON_MULTIARCH)
166        set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
167    else()
168        set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
169    endif()
170    #message(STATUS "Searching for Python libs in ${_PYTHON_LIBS_SEARCH}")
171    # Probably this needs to be more involved. It would be nice if the config
172    # information the python interpreter itself gave us were more complete.
173    find_library(PYTHON_LIBRARY
174        NAMES "python${PYTHON_LIBRARY_SUFFIX}"
175        PATHS ${_PYTHON_LIBS_SEARCH}
176        NO_DEFAULT_PATH)
177
178    # If all else fails, just set the name/version and let the linker figure out the path.
179    if(NOT PYTHON_LIBRARY)
180        set(PYTHON_LIBRARY python${PYTHON_LIBRARY_SUFFIX})
181    endif()
182endif()
183
184MARK_AS_ADVANCED(
185  PYTHON_LIBRARY
186  PYTHON_INCLUDE_DIR
187)
188
189# We use PYTHON_INCLUDE_DIR, PYTHON_LIBRARY and PYTHON_DEBUG_LIBRARY for the
190# cache entries because they are meant to specify the location of a single
191# library. We now set the variables listed by the documentation for this
192# module.
193SET(PYTHON_INCLUDE_DIRS "${PYTHON_INCLUDE_DIR}")
194SET(PYTHON_LIBRARIES "${PYTHON_LIBRARY}")
195SET(PYTHON_DEBUG_LIBRARIES "${PYTHON_DEBUG_LIBRARY}")
196
197find_package_message(PYTHON
198    "Found PythonLibs: ${PYTHON_LIBRARY}"
199    "${PYTHON_EXECUTABLE}${PYTHON_VERSION}")
200
201set(PYTHONLIBS_FOUND TRUE)
202set(PythonLibsNew_FOUND TRUE)
203