File: CMakePushCheckState.cmake

package info (click to toggle)
cmake 4.1.0-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 147,284 kB
  • sloc: ansic: 403,915; cpp: 290,772; sh: 4,102; python: 3,357; yacc: 3,106; lex: 1,189; f90: 532; asm: 471; lisp: 375; cs: 270; java: 266; fortran: 230; perl: 217; objc: 215; xml: 198; makefile: 97; javascript: 83; pascal: 63; tcl: 55; php: 25; ruby: 22
file content (235 lines) | stat: -rw-r--r-- 8,208 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file LICENSE.rst or https://cmake.org/licensing for details.

include_guard(GLOBAL)

#[=======================================================================[.rst:
CMakePushCheckState
-------------------

This module provides commands for managing the state of variables that influence
how various CMake check commands (e.g., :command:`check_symbol_exists`, etc.)
are performed.

Load this module in CMake project with:

.. code-block:: cmake

  include(CMakePushCheckState)

This module provides the following commands, which are useful for scoped
configuration, for example, in CMake modules or when performing checks in a
controlled environment, ensuring that temporary modifications are isolated
to the scope of the check and do not propagate into other parts of the build
system:

* :command:`cmake_push_check_state`
* :command:`cmake_reset_check_state`
* :command:`cmake_pop_check_state`

Affected Variables
^^^^^^^^^^^^^^^^^^

The following CMake variables are saved, reset, and restored by this module's
commands:

.. include:: /module/include/CMAKE_REQUIRED_FLAGS.rst

.. include:: /module/include/CMAKE_REQUIRED_DEFINITIONS.rst

.. include:: /module/include/CMAKE_REQUIRED_INCLUDES.rst

.. include:: /module/include/CMAKE_REQUIRED_LINK_OPTIONS.rst

.. include:: /module/include/CMAKE_REQUIRED_LIBRARIES.rst

.. include:: /module/include/CMAKE_REQUIRED_LINK_DIRECTORIES.rst

.. include:: /module/include/CMAKE_REQUIRED_QUIET.rst

``CMAKE_EXTRA_INCLUDE_FILES``
  .. versionadded:: 3.6
    Previously used already by the :command:`check_type_size` command;  now
    also supported by this module.

  A :ref:`semicolon-separated list <CMake Language Lists>` of extra header
  files to include when performing the check.

.. note::

  Other CMake variables, such as :variable:`CMAKE_<LANG>_FLAGS`, propagate
  to all checks regardless of commands provided by this module, as those
  fundamental variables are designed to influence the global state of the
  build system.

Commands
^^^^^^^^

.. command:: cmake_push_check_state

  Pushes (saves) the current states of the above variables onto a stack:

  .. code-block:: cmake

    cmake_push_check_state([RESET])

  Use this command to preserve the current configuration before making
  temporary modifications for specific checks.

  ``RESET``
    When this option is specified, the command not only saves the current states
    of the listed variables but also resets them to empty, allowing them to be
    reconfigured from a clean state.

.. command:: cmake_reset_check_state

  Resets (clears) the contents of the variables listed above to empty states:

  .. code-block:: cmake

    cmake_reset_check_state()

  Use this command when performing multiple sequential checks that require
  entirely new configurations, ensuring no previous configuration
  unintentionally carries over.

.. command:: cmake_pop_check_state

  Restores the states of the variables listed above to their values at the time
  of the most recent ``cmake_push_check_state()`` call:

  .. code-block:: cmake

    cmake_pop_check_state()

  Use this command to revert temporary changes made during a check.  To
  prevent unexpected behavior, pair each ``cmake_push_check_state()`` with a
  corresponding ``cmake_pop_check_state()``.

Examples
^^^^^^^^

Example: Isolated Check With Compile Definitions
""""""""""""""""""""""""""""""""""""""""""""""""

In the following example, a check for the C symbol ``memfd_create()`` is
performed with an additional ``_GNU_SOURCE`` compile definition,  without
affecting global compile flags.  The ``RESET`` option is used to ensure
that any prior values of the check-related variables are explicitly cleared
before the check.

.. code-block:: cmake

  include(CMakePushCheckState)

  # Save and reset the current state
  cmake_push_check_state(RESET)

  # Perform check with specific compile definitions
  set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
  include(CheckSymbolExists)
  check_symbol_exists(memfd_create "sys/mman.h" HAVE_MEMFD_CREATE)

  # Restore the original state
  cmake_pop_check_state()

Example: Nested Configuration Scopes
""""""""""""""""""""""""""""""""""""

In the following example, variable states are pushed onto the stack multiple
times, allowing for sequential or nested checks.  Each
``cmake_pop_check_state()`` restores the most recent pushed states.

.. code-block:: cmake

  include(CMakePushCheckState)

  # Save and reset the current state
  cmake_push_check_state(RESET)

  # Perform the first check with additional libraries
  set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_DL_LIBS})
  include(CheckSymbolExists)
  check_symbol_exists(dlopen "dlfcn.h" HAVE_DLOPEN)

  # Save current state
  cmake_push_check_state()

  # Perform the second check with libraries and additional compile definitions
  set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
  check_symbol_exists(dladdr "dlfcn.h" HAVE_DLADDR)

  message(STATUS "${CMAKE_REQUIRED_DEFINITIONS}")
  # Output: -D_GNU_SOURCE

  # Restore the previous state
  cmake_pop_check_state()

  message(STATUS "${CMAKE_REQUIRED_DEFINITIONS}")
  # Output here is empty

  # Reset variables to prepare for the next check
  cmake_reset_check_state()

  # Perform the next check only with additional compile definitions
  set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
  check_symbol_exists(dl_iterate_phdr "link.h" HAVE_DL_ITERATE_PHDR)

  # Restore the original state
  cmake_pop_check_state()
#]=======================================================================]

macro(CMAKE_RESET_CHECK_STATE)

  set(CMAKE_EXTRA_INCLUDE_FILES)
  set(CMAKE_REQUIRED_INCLUDES)
  set(CMAKE_REQUIRED_DEFINITIONS)
  set(CMAKE_REQUIRED_LINK_OPTIONS)
  set(CMAKE_REQUIRED_LIBRARIES)
  set(CMAKE_REQUIRED_LINK_DIRECTORIES)
  set(CMAKE_REQUIRED_FLAGS)
  set(CMAKE_REQUIRED_QUIET)

endmacro()

macro(CMAKE_PUSH_CHECK_STATE)

  if(NOT DEFINED _CMAKE_PUSH_CHECK_STATE_COUNTER)
    set(_CMAKE_PUSH_CHECK_STATE_COUNTER 0)
  endif()

  math(EXPR _CMAKE_PUSH_CHECK_STATE_COUNTER "${_CMAKE_PUSH_CHECK_STATE_COUNTER}+1")

  set(_CMAKE_EXTRA_INCLUDE_FILES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}        ${CMAKE_EXTRA_INCLUDE_FILES})
  set(_CMAKE_REQUIRED_INCLUDES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}          ${CMAKE_REQUIRED_INCLUDES})
  set(_CMAKE_REQUIRED_DEFINITIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}       ${CMAKE_REQUIRED_DEFINITIONS})
  set(_CMAKE_REQUIRED_LINK_OPTIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}      ${CMAKE_REQUIRED_LINK_OPTIONS})
  set(_CMAKE_REQUIRED_LIBRARIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}         ${CMAKE_REQUIRED_LIBRARIES})
  set(_CMAKE_REQUIRED_LINK_DIRECTORIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}  ${CMAKE_REQUIRED_LINK_DIRECTORIES})
  set(_CMAKE_REQUIRED_FLAGS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}             ${CMAKE_REQUIRED_FLAGS})
  set(_CMAKE_REQUIRED_QUIET_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}             ${CMAKE_REQUIRED_QUIET})

  if (${ARGC} GREATER 0 AND "${ARGV0}" STREQUAL "RESET")
    cmake_reset_check_state()
  endif()

endmacro()

macro(CMAKE_POP_CHECK_STATE)

# don't pop more than we pushed
  if("${_CMAKE_PUSH_CHECK_STATE_COUNTER}" GREATER "0")

    set(CMAKE_EXTRA_INCLUDE_FILES       ${_CMAKE_EXTRA_INCLUDE_FILES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_INCLUDES         ${_CMAKE_REQUIRED_INCLUDES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_DEFINITIONS      ${_CMAKE_REQUIRED_DEFINITIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_LINK_OPTIONS     ${_CMAKE_REQUIRED_LINK_OPTIONS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_LIBRARIES        ${_CMAKE_REQUIRED_LIBRARIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_LINK_DIRECTORIES ${_CMAKE_REQUIRED_LINK_DIRECTORIES_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_FLAGS            ${_CMAKE_REQUIRED_FLAGS_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})
    set(CMAKE_REQUIRED_QUIET            ${_CMAKE_REQUIRED_QUIET_SAVE_${_CMAKE_PUSH_CHECK_STATE_COUNTER}})

    math(EXPR _CMAKE_PUSH_CHECK_STATE_COUNTER "${_CMAKE_PUSH_CHECK_STATE_COUNTER}-1")
  endif()

endmacro()