| # Ceres Solver - A fast non-linear least squares minimizer | 
 | # Copyright 2019 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) | 
 |  | 
 | # Usage: enable_sanitizer(REQUIRED_SANITIZERS) where REQUIRED_SANITIZERS should | 
 | # contain the list of sanitizers to enable by updating CMAKE_CXX_FLAGS and | 
 | # CMAKE_EXE_LINKER_FLAGS. | 
 | # | 
 | # The specified sanitizers will be checked both for compatibility with the | 
 | # current compiler and with each other as some sanitizers are mutually | 
 | # exclusive. | 
 | macro(enable_sanitizer) | 
 |   # According to the Clang documentation [1] the following sanitizers are | 
 |   # mututally exclusive. | 
 |   # [1]: https://clang.llvm.org/docs/UsersManual.html#controlling-code-generation | 
 |   set(INCOMPATIBLE_SANITIZERS address thread memory) | 
 |   # Set the recommended additional common compile flags for any sanitizer to | 
 |   # get the best possible output, e.g [2] but make them visible in the cache | 
 |   # so that the user can edit them if required. | 
 |   # [2]: https://clang.llvm.org/docs/AddressSanitizer.html#usage | 
 |   set(COMMON_SANITIZER_COMPILE_OPTIONS | 
 |     "-g -fno-omit-frame-pointer -fno-optimize-sibling-calls" | 
 |     CACHE STRING "Common compile flags enabled for any sanitizer") | 
 |  | 
 |   # Check that the specified list of sanitizers to enable does not include | 
 |   # multiple entries from the incompatible list. | 
 |   set(MERGED_SANITIZERS ${ARGN} ${INCOMPATIBLE_SANITIZERS}) | 
 |   list(LENGTH MERGED_SANITIZERS COMBINED_LENGTH) | 
 |   list(REMOVE_DUPLICATES MERGED_SANITIZERS) | 
 |   list(LENGTH MERGED_SANITIZERS COMBINED_LENGTH_NO_DUPLICATES) | 
 |   math(EXPR VALID_LENGTH "${COMBINED_LENGTH} - 1") | 
 |   if (COMBINED_LENGTH_NO_DUPLICATES LESS VALID_LENGTH) | 
 |     include(PrettyPrintCMakeList) | 
 |     pretty_print_cmake_list(REQUESTED_SANITIZERS ${ARGN}) | 
 |     pretty_print_cmake_list( | 
 |       PRETTY_INCOMPATIBLE_SANITIZERS ${INCOMPATIBLE_SANITIZERS}) | 
 |     message(FATAL_ERROR "Found incompatible sanitizers in requested set: " | 
 |       "${REQUESTED_SANITIZERS}. The following sanitizers are mutually " | 
 |       "exclusive: ${PRETTY_INCOMPATIBLE_SANITIZERS}") | 
 |   endif() | 
 |  | 
 |   # Until CMake 3.14 and CMAKE_REQUIRED_LINK_OPTIONS there was no equivalent to | 
 |   # CMAKE_REQUIRED_FLAGS for try_compile() for linker flags. However, in CMake | 
 |   # 3.2 CMP0056 was introduced that when enabled passes CMAKE_EXE_LINKER_FLAGS | 
 |   # to try_compile() which allows us to achieve the same effect. | 
 |   cmake_policy(SET CMP0056 NEW) | 
 |   include(CheckCXXCompilerFlag) | 
 |  | 
 |   unset(ADDED_SANITIZER) | 
 |   foreach(REQUESTED_SANITIZER ${ARGN}) | 
 |     set(SANITIZER_FLAG -fsanitize=${REQUESTED_SANITIZER}) | 
 |     # Save the current CMAKE_EXE_LINKER_FLAGS before modifying it to test for | 
 |     # the existence of the sanitizer flag so that we can revert after the test. | 
 |     set(INITIAL_CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}") | 
 |     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${SANITIZER_FLAG}") | 
 |     check_cxx_compiler_flag(${SANITIZER_FLAG} HAVE_SANITIZER) | 
 |     set(CMAKE_EXE_LINKER_FLAGS "${INITIAL_CMAKE_EXE_LINKER_FLAGS}") | 
 |     if (NOT HAVE_SANITIZER) | 
 |       message(FATAL_ERROR "Specified sanitizer: ${REQUESTED_SANITIZER} is not " | 
 |         "supported by the compiler.") | 
 |     endif() | 
 |     message(STATUS "Enabling sanitizer: ${REQUESTED_SANITIZER}") | 
 |     set(ADDED_SANITIZER TRUE) | 
 |     # As per the Clang documentation, the sanitizer flags must be added to both | 
 |     # the compiler and linker flags. | 
 |     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SANITIZER_FLAG}") | 
 |     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${SANITIZER_FLAG}") | 
 |   endforeach() | 
 |   if (ADDED_SANITIZER) | 
 |     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COMMON_SANITIZER_COMPILE_OPTIONS}") | 
 |   endif() | 
 | endmacro() |