关于Visual Studio：如何使用cmake检测64位MSVC？

How to detect if 64 bit MSVC with cmake?

我有一个使用cmake的项目，一个目标设置为仅使用MSVC构建：

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if (MSVC)
add_library(test SHARED source.cpp)
endif()

现在另一个问题是该目标仅适用于MSVC 32位。那么，如何检测生成器是MSVC64并跳过此目标？

检查您是否为64位体系结构生成的通常方法是测试CMAKE_SIZEOF_VOID_P：

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if(CMAKE_SIZEOF_VOID_P EQUAL 8)
# 64 bits
elseif(CMAKE_SIZEOF_VOID_P EQUAL 4)
# 32 bits
endif()

相关讨论

在最新版本的CMake / Visual Studio中，位数是通过CMAKE_GENERATOR_PLATFORM选择的，可以在命令行上使用-A选项指定：

1	cmake -G"Visual Studio 16 2019" -A Win32 -DCMAKE_BUILD_TYPE=Release ..

因此，基于此功能，您可以从CMakeLists.txt中查询值：

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if(NOT ("${CMAKE_GENERATOR_PLATFORM}" STREQUAL"Win64"))
...
ENDIF()

这是我最初开始编写的脚本，用于检测目标是x86(32位x86)还是amd64(64位x86)。然后，我找到了Jake Petroules的脚本，并继续吸收了从Internet上搜出的多个来源的点点滴滴，通常使用C编译器来检测目标体系结构。有许多不同的C编译器，它们给出了许多不一致的答案。该脚本旨在处理所有这些问题(理论上)，并赋予CMake更高的检测保真度。它通过使用预处理器传达回CMake脚本来工作。将其放在您的CMake模块文件夹中，并至少include()在您的项目中将其放置一次(它具有包含保护，因此可以包含多个包含物)。然后，在included()此脚本的文件夹以及所有子文件夹中，将有一个变量CMAKE_CPU_ARCHITECTURES。该变量是一个列表(因为XCode项目文件可以一次针对多个体系结构)。您应该检查一下想要的列表中是否有该列表。

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if("amd64" IN_LIST CMAKE_CPU_ARCHITECTURES) # I am targeting 64-bit x86.
...
if("x86" IN_LIST CMAKE_CPU_ARCHITECTURES) # I am targeting 32-bit x86.
...

x86(32位)或amd64(64位)。这只是目标架构(即CPU芯片)。要检测操作系统，生成器，编译器等是另一回事，但是您可以使用嵌套在各种其他if语句中的体系结构检查，例如if(WIN32)(令人困惑的意思是只针对某种Windows，不一定是32位)或if(MSVC)(如果您对编译器感兴趣)等等，依此类推，视情况而定。

(我有一个类似的脚本来检查特定的操作系统，它能够检测特定的事物并返回诸如watchOS vs. iOS vs. macOS或Windows CE之类的值，依此类推，但这是另一回事了。 )。

detect_cpu_architectures.cmake：

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if(NOT detect_cpu_architectures_INC) # include guard
set(detect_cpu_architectures_INC)

# This code was originally written by Jake Petroules,
# https://github.com/axr/solar-cmake/blob/master/TargetArch.cmake

# then edited/extended by Daniel Russell with help from
# https://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/global/qprocessordetection.h
# https://opensource.apple.com/source/WTFEmbedded/WTFEmbedded-95/wtf/Platform.h.auto.html
# http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.kui0098a/armccref_babjidgc.htm
# https://sourceforge.net/p/predef/wiki/Architectures/
# https://blog.kowalczyk.info/article/j/guide-to-predefined-macros-in-c-compilers-gcc-clang-msvc-etc..html

# Regarding POWER/PowerPC, just as is noted in the Qt source,
#"There are many more known variants/revisions that we do not handle/detect."
# Set ppc_support to TRUE before including this file or ppc and ppc64
# will be treated as invalid architectures since they are no longer supported by Apple

# TODO: add more chips!!!! Tedious though.
enable_language(C) # this must be at file-scope not function scope. Thus include-guard.

set(archdetect_c_code"
/* -----------------------------------ARM ---------------------------------- */

#if defined(__ARM64_ARCH_8__) || defined(__aarch64__) || defined(__ARMv8__) || defined(__ARMv8_A__) || defined(_M_ARM64)
#if defined(__thumb__) || defined(_M_ARMT)
#error cmake_ARCH armthumbv3
#elif
#error cmake_ARCH armv8
#endif

#elif defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__ ) || defined(__ARM_ARCH_7F__) || defined(__ARM_ARCH_7S__) || (defined(__TARGET_ARCH_ARM) && __TARGET_ARCH_ARM-0 >= 7)
#if defined(__thumb__) || defined(__thumb2__) || defined(_M_ARMT)
#error cmake_ARCH armthumbv2
#elif
#error cmake_ARCH armv7
#endif

#elif defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) || defined(__ARM_ARCH_6M__) || (defined(__TARGET_ARCH_ARM) && __TARGET_ARCH_ARM-0 >= 6)
#if defined(__thumb__) || defined(_M_ARMT)
#error cmake_ARCH armthumbv1
#elif
#error cmake_ARCH armv6
#endif

#elif defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5E__ ) || defined(__ARM_ARCH_5T__) || defined(__ARM_ARCH_5TE__) || defined(__ARM_ARCH_5TEJ__) || defined(__MARM_ARMV5__) || (defined(__TARGET_ARCH_ARM) && __TARGET_ARCH_ARM-0 >= 5)
#error cmake_ARCH armv5

#elif defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__) || defined(__MARM_ARMV4__)
#error cmake_ARCH armv4

#elif defined(__TARGET_ARCH_ARM)
#error cmake_ARCH armv ## __TARGET_ARCH_ARM

#elif defined(__arm__) || defined(_M_ARM)
#error arm

/* ----------------------------------- x86 ---------------------------------- */

#elif defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(i386) || defined(_M_IX86) || defined(_X86_) || defined(__THW_INTEL)
#error cmake_ARCH x86

#elif defined(__x86_64) || defined(__x86_64__) || defined(__amd64) || defined(_M_X64) || defined(__amd64__) || defined(_M_AMD64)
#error cmake_ARCH amd64

// AMD wrote the original x86_64 bit spec after cloning x86 for years.
// Then, in 2003, they renamed it to amd64. So basically x64 ~ amd64 ~ x86_64
// But the trend seems to be to tidy this up and go with the most officialish, amd64.
// Think of it this way, AMD was in fact the one pushing the architecture forwards at times.
// Even if Intel invented it. Therefore, I say, let's stick with amd64 and be over this mess already.

/* ------------------------------- Itanium ---------------------------------- */

#elif defined(__ia64) || defined(__ia64__) || defined(_M_IA64) || defined(_IA64) || defined(__IA64__) || defined(__itanium__)
/* 32-bit mode on Itanium */
#if !defined(__LP64__) && !defined(_M_X64) /* <-- Visual Studio macro (it USED to support Itanium) */
#error cmake_ARCH ia32
#else
#error cmake_ARCH ia64
#endif

/* ------------------------------ Power PC --------------------------------- */

#elif defined(__ppc__) || defined(__ppc) || defined(__PPC__) || defined(__PPC) || defined(__powerpc__) || defined(__powerpc) || defined(_ARCH_COM) || defined(_ARCH_PWR) || defined(_ARCH_PPC) || defined(_M_MPPC) || defined(_M_PPC) || defined(__POWERPC__)
#if defined(__ppc64__) || defined(__PPC64__) || defined(__powerpc64__) || defined(__64BIT__)
#error cmake_ARCH ppc64
#else
#error cmake_ARCH ppc32
#endif

/* ---------------------------------- Sparc --------------------------------- */

#elif defined(__sparc) && !defined(__arch64__) || defined(__sparcv8)
#error cmake_ARCH sparc32

#elif defined(__sparc__) && defined(__arch64__) || defined (__sparcv9)
#error cmake_ARCH sparc64

/* --------------------------- IBM Mainframes ------------------------------- */

/* 64 bit IBM z/Architecture */
#elif defined(__s390x__) || defined(__s390X__) || defined(__zarch__) || defined(__SYSC_ZARCH__)
#error cmake_ARCH zArch

/* Older 32 bit IBM System/390, maybe useful for Hercules emulation? */
#elif defined(__s390__)
#error cmake_ARCH s390

/* --------------------------- Hitachi SuperH ------------------------------- */

#elif defined(__sh1__)
#error cmake_ARCH superH1
#elif defined(__sh2__)
#error cmake_ARCH superH2
#elif defined(__sh3__) || defined(__SH3__)
#error cmake_ARCH superH3
#elif defined(__SH4__)
#error cmake_ARCH superH4
#elif defined(__SH5__)
#error cmake_ARCH superH5
#elif defined(__sh__) // not sure which version...unlikely?
#error cmake_ARCH superH

/* -------------------------- Analog Devices --------------------------------- */

#elif defined(__bfin) || defined(__BFIN__)
#error cmake_ARCH blackfin
#elif defined(__ADSPTS101__)
#error cmake_ARCH adps-ts101
#elif defined(__ADSPTS201__)
#error cmake_ARCH adps-ts201
#elif defined(__ADSPTS202__)
#error cmake_ARCH adps-ts202
#elif defined(__ADSPTS203__)
#error cmake_ARCH adps-ts203
#elif defined(__ADSPTS20x__) // this will be true for any of the above but we use as catchall
#error cmake_ARCH adps-ts20x

/* ------------------------------- Alpha ------------------------------------- */

#elif defined(__alpha_ev4__)
#error cmake_ARCH alpha_ev4
#elif defined(__alpha_ev5__)
#error cmake_ARCH alpha_ev5
#elif defined(__alpha_ev6__)
#error cmake_ARCH alpha_ev6
#elif defined(__alpha__) || defined(__alpha) || defined(_M_ALPHA)
#error cmake_ARCH alpha

/* ------------------------- Texas Instruments ------------------------------ */

#elif defined(_TMS320C6200)
#error cmake_ARCH c6200
#elif defined(_TMS320C6400)
#error cmake_ARCH c6400
#elif defined(_TMS320C6400_PLUS)
#error cmake_ARCH c6400+
#elif defined(_TMS320C6600)
#error cmake_ARCH c6600
#elif defined(_TMS320C6700)
#error cmake_ARCH c6700
#elif defined(_TMS320C6700_PLUS)
#error cmake_ARCH c6700+
#elif defined(_TMS320C6740)
#error cmake_ARCH c6740
#elif defined(__TMS470__)
#error cmake_ARCH tms470

/* -------------------------- Hewlett Packard ------------------------------ */

#elif defined(_PA_RISC1_0)
#error cmake_ARCH parisc1_0

#elif defined(_PA_RISC1_1) || defined(__HPPA11__) || defined(__PA7100__)
#error cmake_ARCH parisc1_1

#elif defined(_PA_RISC2_0) || defined(__RISC2_0__) || defined(__HPPA20__) || defined(__PA8000__)
#error cmake_ARCH parisc2_0

#elif defined(__hppa__) || defined(__HPPA__) || defined(__hppa)
#error cmake_ARCH parisc

/* ---------------------------- Adapteva --------------------------------- */

#elif defined(__epiphany__)
#error cmake_ARCH ephiphany

/* ------------------------------ MIPS ---------------------------------- */

#elif defined(_MIPS_ISA_MIPS1) || (__mips == 1)
#error cmake_ARCH mips1
#elif defined(_MIPS_ISA_MIPS2) || defined(__MIPS_ISA2__) || (__mips == 2)
#error cmake_ARCH mips2
#elif defined(_MIPS_ISA_MIPS3) || defined(__MIPS_ISA3__) || (__mips == 3)
#error cmake_ARCH mips3
#elif defined(_MIPS_ISA_MIPS4) || defined(__MIPS_ISA4__) || (__mips == 4)
#error cmake_ARCH mips4
#elif defined(__MIPS__) || defined(__mips__) || defined(mips) || defined(__mips)
#error cmake_ARCH mips

/* ---------------------------- Motorola -------------------------------- */

#elif defined(__mc68000__) || defined(__MC68000__)
#error cmake_ARCH mc68000
#elif defined(__mc68010__)
#error cmake_ARCH mc68010
#elif defined(__mc68020__) || defined(__MC68020__)
#error cmake_ARCH mc68020
#elif defined(__mc68030__) || defined(__MC68030__)
#error cmake_ARCH mc68030
#elif defined(__mc68040__) || defined(__MC68040__)
#error cmake_ARCH mc68040
#elif defined(__mc68060__) || defined(__MC68060__)
#error cmake_ARCH mc68060
#elif defined(__m68k__) || defined(M68000) || defined(__MC68K__)
#error cmake_ARCH mc68

#endif
")

if(APPLE AND CMAKE_OSX_ARCHITECTURES)
# On OS X we use CMAKE_OSX_ARCHITECTURES *if* it was set
# First let's normalize the order of the values

# Note that it's not possible to compile PowerPC applications if you are using
# the OS X SDK version 10.6 or later - you'll need 10.4/10.5 for that, so we
# disable it by default
# See this page for more information:
# http://stackoverflow.com/questions/5333490/how-can-we-restore-ppc-ppc64-as-well-as-full-10-4-10-5-sdk-support-to-xcode-4

# Architecture defaults to x86 or ppc on OS X 10.5 and earlier, depending on the CPU type detected at runtime.
# On OS X 10.6+ the default is x86_64 if the CPU supports it, x86 otherwise.

foreach(osx_arch ${CMAKE_OSX_ARCHITECTURES})
if("${osx_arch}" STREQUAL"ppc" AND ppc_support)
set(osx_arch_ppc TRUE)
elseif("${osx_arch}" STREQUAL"i386")
set(osx_arch_i386 TRUE)
elseif("${osx_arch}" STREQUAL"x86_64")
set(osx_arch_x86_64 TRUE)
elseif("${osx_arch}" STREQUAL"ppc64" AND ppc_support)
set(osx_arch_ppc64 TRUE)
else()
message(FATAL_ERROR"Invalid OS X arch name: ${osx_arch}")
endif()
endforeach()

# Now add all the architectures in our normalized order
if(osx_arch_ppc)
list(APPEND ARCH ppc32)
endif()

if(osx_arch_i386)
list(APPEND ARCH x86)
endif()

if(osx_arch_x86_64)
list(APPEND ARCH x64)
endif()

if(osx_arch_ppc64)
list(APPEND ARCH ppc64)
endif()
else()
file(WRITE"${CMAKE_BINARY_DIR}/CMakeFiles/detect_cpu_arch.c""${archdetect_c_code}")

# Detect the architecture in a rather creative way...
# This compiles a small C program which is a series of ifdefs that selects a
# particular #error preprocessor directive whose message string contains the
# target architecture. The program will always fail to compile (both because
# file is not a valid C program, and obviously because of the presence of the
# #error preprocessor directives... but by exploiting the preprocessor in this
# way, we can detect the correct target architecture even when cross-compiling,
# since the program itself never needs to be run (only the compiler/preprocessor)
try_run(
run_result_unused
compile_result_unused
"${CMAKE_BINARY_DIR}/CMakeFiles"
"${CMAKE_BINARY_DIR}/CMakeFiles/detect_cpu_arch.c"
COMPILE_OUTPUT_VARIABLE ARCH
CMAKE_FLAGS CMAKE_OSX_ARCHITECTURES=${CMAKE_OSX_ARCHITECTURES}
)

# Parse the architecture name from the compiler output
string(REGEX MATCH"cmake_ARCH ([a-zA-Z0-9_]+)" ARCH"${ARCH}")

# Get rid of the value marker leaving just the architecture name
string(REPLACE"cmake_ARCH""" ARCH"${ARCH}")

# If we are compiling with an unknown architecture this variable should
# already be set to"unknown" but in the case that it's empty (i.e. due
# to a typo in the code), then set it to unknown
if (NOT ARCH)
set(ARCH unknown)
endif()
endif()

set(CMAKE_CPU_ARCHITECTURES"${ARCH}")

endif(NOT detect_cpu_architectures_INC) # include guard