ceph/cmake/modules/FindBacktrace.cmake

   1 #.rst:
   2 # FindBacktrace
   3 # -------------
   4 #
   5 # Find provider for backtrace(3).
   6 #
   7 # Checks if OS supports backtrace(3) via either libc or custom library.
   8 # This module defines the following variables:
   9 #
  10 # ``Backtrace_HEADER``
  11 #   The header file needed for backtrace(3). Cached.
  12 #   Could be forcibly set by user.
  13 # ``Backtrace_INCLUDE_DIRS``
  14 #   The include directories needed to use backtrace(3) header.
  15 # ``Backtrace_LIBRARIES``
  16 #   The libraries (linker flags) needed to use backtrace(3), if any.
  17 # ``Backtrace_FOUND``
  18 #   Is set if and only if backtrace(3) support detected.
  19 #
  20 # The following cache variables are also available to set or use:
  21 #
  22 # ``Backtrace_LIBRARY``
  23 #   The external library providing backtrace, if any.
  24 # ``Backtrace_INCLUDE_DIR``
  25 #   The directory holding the backtrace(3) header.
  26 #
  27 # Typical usage is to generate of header file using configure_file() with the
  28 # contents like the following::
  29 #
  30 #  #cmakedefine01 Backtrace_FOUND
  31 #  #if Backtrace_FOUND
  32 #  # include <${Backtrace_HEADER}>
  33 #  #endif
  34 #
  35 # And then reference that generated header file in actual source.
  36
  37 #=============================================================================
  38 # Copyright 2013 Vadim Zhukov
  39 #
  40 # Distributed under the OSI-approved BSD License (the "License");
  41 # see accompanying file Copyright.txt for details.
  42 #
  43 # This software is distributed WITHOUT ANY WARRANTY; without even the
  44 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  45 # See the License for more information.
  46 #=============================================================================
  47 # (To distribute this file outside of CMake, substitute the full
  48 #  License text for the above reference.)
  49
  50
  51 include(CMakePushCheckState)
  52 include(CheckSymbolExists)
  53 include(FindPackageHandleStandardArgs)
  54
  55 # List of variables to be provided to find_package_handle_standard_args()
  56 set(_Backtrace_STD_ARGS Backtrace_INCLUDE_DIR)
  57
  58 if(Backtrace_HEADER)
  59   set(_Backtrace_HEADER_TRY "${Backtrace_HEADER}")
  60 else(Backtrace_HEADER)
  61   set(_Backtrace_HEADER_TRY "execinfo.h")
  62 endif(Backtrace_HEADER)
  63
  64 find_path(Backtrace_INCLUDE_DIR "${_Backtrace_HEADER_TRY}")
  65 set(Backtrace_INCLUDE_DIRS ${Backtrace_INCLUDE_DIR})
  66
  67 if (NOT DEFINED Backtrace_LIBRARY)
  68   # First, check if we already have backtrace(), e.g., in libc
  69   cmake_push_check_state(RESET)
  70   set(CMAKE_REQUIRED_INCLUDES ${Backtrace_INCLUDE_DIRS})
  71   set(CMAKE_REQUIRED_QUIET ${Backtrace_FIND_QUIETLY})
  72   check_symbol_exists("backtrace" "${_Backtrace_HEADER_TRY}" _Backtrace_SYM_FOUND)
  73   cmake_pop_check_state()
  74 endif()
  75
  76 if(_Backtrace_SYM_FOUND)
  77   # Avoid repeating the message() call below each time CMake is run.
  78   if(NOT Backtrace_FIND_QUIETLY AND NOT DEFINED Backtrace_LIBRARY)
  79     message(STATUS "backtrace facility detected in default set of libraries")
  80   endif()
  81   set(Backtrace_LIBRARY "" CACHE FILEPATH "Library providing backtrace(3), empty for default set of libraries")
  82 else()
  83   # Check for external library, for non-glibc systems
  84   if(Backtrace_INCLUDE_DIR)
  85     # OpenBSD has libbacktrace renamed to libexecinfo
  86     find_library(Backtrace_LIBRARY "execinfo")
  87   elseif()     # respect user wishes
  88     set(_Backtrace_HEADER_TRY "backtrace.h")
  89     find_path(Backtrace_INCLUDE_DIR ${_Backtrace_HEADER_TRY})
  90     find_library(Backtrace_LIBRARY "backtrace")
  91   endif()
  92
  93   # Prepend list with library path as it's more common practice
  94   set(_Backtrace_STD_ARGS Backtrace_LIBRARY ${_Backtrace_STD_ARGS})
  95 endif()
  96
  97 set(Backtrace_LIBRARIES ${Backtrace_LIBRARY})
  98 set(Backtrace_HEADER "${_Backtrace_HEADER_TRY}" CACHE STRING "Header providing backtrace(3) facility")
  99
 100 find_package_handle_standard_args(Backtrace FOUND_VAR Backtrace_FOUND REQUIRED_VARS ${_Backtrace_STD_ARGS})
 101 mark_as_advanced(Backtrace_HEADER Backtrace_INCLUDE_DIR Backtrace_LIBRARY)