1 # The macro choose_msvc_crt() takes a list of possible
2 # C runtimes to choose from, in the form of compiler flags,
3 # to present to the user. (MTd for /MTd, etc)
5 # The macro is invoked at the end of the file.
7 # CMake already sets CRT flags in the CMAKE_CXX_FLAGS_* and
8 # CMAKE_C_FLAGS_* variables by default. To let the user
9 # override that for each build type:
10 # 1. Detect which CRT is already selected, and reflect this in
11 # LLVM_USE_CRT_* so the user can have a better idea of what
12 # changes they're making.
13 # 2. Replace the flags in both variables with the new flag via a regex.
14 # 3. set() the variables back into the cache so the changes
17 ### Helper macros: ###
18 macro(make_crt_regex regex crts)
20 foreach(crt ${${crts}})
21 # Trying to match the beginning or end of the string with stuff
22 # like [ ^]+ didn't work, so use a bunch of parentheses instead.
23 set(${regex} "${${regex}}|(^| +)/${crt}($| +)")
25 string(REGEX REPLACE "^\\|" "" ${regex} "${${regex}}")
26 endmacro(make_crt_regex)
28 macro(get_current_crt crt_current regex flagsvar)
29 # Find the selected-by-CMake CRT for each build type, if any.
30 # Strip off the leading slash and any whitespace.
31 string(REGEX MATCH "${${regex}}" ${crt_current} "${${flagsvar}}")
32 string(REPLACE "/" " " ${crt_current} "${${crt_current}}")
33 string(STRIP "${${crt_current}}" ${crt_current})
34 endmacro(get_current_crt)
36 # Replaces or adds a flag to a variable.
37 # Expects 'flag' to be padded with spaces.
38 macro(set_flag_in_var flagsvar regex flag)
39 string(REGEX MATCH "${${regex}}" current_flag "${${flagsvar}}")
40 if("${current_flag}" STREQUAL "")
41 set(${flagsvar} "${${flagsvar}}${${flag}}")
43 string(REGEX REPLACE "${${regex}}" "${${flag}}" ${flagsvar} "${${flagsvar}}")
45 string(STRIP "${${flagsvar}}" ${flagsvar})
46 # Make sure this change gets reflected in the cache/gui.
47 # CMake requires the docstring parameter whenever set() touches the cache,
48 # so get the existing docstring and re-use that.
49 get_property(flagsvar_docs CACHE ${flagsvar} PROPERTY HELPSTRING)
50 set(${flagsvar} "${${flagsvar}}" CACHE STRING "${flagsvar_docs}" FORCE)
51 endmacro(set_flag_in_var)
54 macro(choose_msvc_crt MSVC_CRT)
57 "LLVM_USE_CRT is deprecated. Use the CMAKE_BUILD_TYPE-specific
58 variables (LLVM_USE_CRT_DEBUG, etc) instead.")
61 make_crt_regex(MSVC_CRT_REGEX ${MSVC_CRT})
63 foreach(build_type ${CMAKE_CONFIGURATION_TYPES} ${CMAKE_BUILD_TYPE})
64 string(TOUPPER "${build_type}" build)
65 if (NOT LLVM_USE_CRT_${build})
66 get_current_crt(LLVM_USE_CRT_${build}
68 CMAKE_CXX_FLAGS_${build})
69 set(LLVM_USE_CRT_${build}
70 "${LLVM_USE_CRT_${build}}"
71 CACHE STRING "Specify VC++ CRT to use for ${build_type} configurations."
73 set_property(CACHE LLVM_USE_CRT_${build}
74 PROPERTY STRINGS ;${${MSVC_CRT}})
75 endif(NOT LLVM_USE_CRT_${build})
76 endforeach(build_type)
78 foreach(build_type ${CMAKE_CONFIGURATION_TYPES} ${CMAKE_BUILD_TYPE})
79 string(TOUPPER "${build_type}" build)
80 if ("${LLVM_USE_CRT_${build}}" STREQUAL "")
83 set(flag_string " /${LLVM_USE_CRT_${build}} ")
84 list(FIND ${MSVC_CRT} ${LLVM_USE_CRT_${build}} idx)
87 "Invalid value for LLVM_USE_CRT_${build}: ${LLVM_USE_CRT_${build}}. Valid options are one of: ${${MSVC_CRT}}")
89 message(STATUS "Using ${build_type} VC++ CRT: ${LLVM_USE_CRT_${build}}")
92 set_flag_in_var(CMAKE_${lang}_FLAGS_${build} MSVC_CRT_REGEX flag_string)
94 endforeach(build_type)
95 endmacro(choose_msvc_crt MSVC_CRT)
98 # List of valid CRTs for MSVC
105 choose_msvc_crt(MSVC_CRT)