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)
4#
5# The macro is invoked at the end of the file.
6#
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
15# are user-visible.
16
17### Helper macros: ###
18macro(make_crt_regex regex crts)
19  set(${regex} "")
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}($| +)")
24  endforeach(crt)
25  string(REGEX REPLACE "^\\|" "" ${regex} "${${regex}}")
26endmacro(make_crt_regex)
27
28macro(get_current_crt crt_current regex flagsvar)
29  # Find the selected-by-CMake CRT for each build type, if any.
30  # Strip off the leading slash and any whitespace.
31  string(REGEX MATCH "${${regex}}" ${crt_current} "${${flagsvar}}")
32  string(REPLACE "/" " " ${crt_current} "${${crt_current}}")
33  string(STRIP "${${crt_current}}" ${crt_current})
34endmacro(get_current_crt)
35
36# Replaces or adds a flag to a variable.
37# Expects 'flag' to be padded with spaces.
38macro(set_flag_in_var flagsvar regex flag)
39  string(REGEX MATCH "${${regex}}" current_flag "${${flagsvar}}")
40  if("${current_flag}" STREQUAL "")
41    set(${flagsvar} "${${flagsvar}}${${flag}}")
42  else()
43    string(REGEX REPLACE "${${regex}}" "${${flag}}" ${flagsvar} "${${flagsvar}}")
44  endif()
45  string(STRIP "${${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)
51endmacro(set_flag_in_var)
52
53
54macro(choose_msvc_crt MSVC_CRT)
55  if(LLVM_USE_CRT)
56    message(FATAL_ERROR
57      "LLVM_USE_CRT is deprecated. Use the CMAKE_BUILD_TYPE-specific
58variables (LLVM_USE_CRT_DEBUG, etc) instead.")
59  endif()
60
61  make_crt_regex(MSVC_CRT_REGEX ${MSVC_CRT})
62
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}
67	MSVC_CRT_REGEX
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 ${build_type} configurations."
72	FORCE)
73      set_property(CACHE LLVM_USE_CRT_${build}
74	PROPERTY STRINGS "";${${MSVC_CRT}})
75    endif(NOT LLVM_USE_CRT_${build})
76  endforeach(build_type)
77
78  foreach(build_type ${CMAKE_CONFIGURATION_TYPES} ${CMAKE_BUILD_TYPE})
79    string(TOUPPER "${build_type}" build)
80    if ("${LLVM_USE_CRT_${build}}" STREQUAL "")
81      set(flag_string " ")
82    else()
83      set(flag_string " /${LLVM_USE_CRT_${build}} ")
84      list(FIND ${MSVC_CRT} ${LLVM_USE_CRT_${build}} idx)
85      if (idx LESS 0)
86        message(FATAL_ERROR
87	  "Invalid value for LLVM_USE_CRT_${build}: ${LLVM_USE_CRT_${build}}. Valid options are one of: ${${MSVC_CRT}}")
88      endif (idx LESS 0)
89      message(STATUS "Using ${build_type} VC++ CRT: ${LLVM_USE_CRT_${build}}")
90    endif()
91    foreach(lang C CXX)
92      set_flag_in_var(CMAKE_${lang}_FLAGS_${build} MSVC_CRT_REGEX flag_string)
93    endforeach(lang)
94  endforeach(build_type)
95endmacro(choose_msvc_crt MSVC_CRT)
96
97
98# List of valid CRTs for MSVC
99set(MSVC_CRT
100  MD
101  MDd
102  MT
103  MTd)
104
105choose_msvc_crt(MSVC_CRT)
106
107