[CMake] Detecting -m32 build target on 64-bit host

[Gregor Jasny]

Hi,

On 23/04/15 16:54, Mateusz Loskot wrote:
> Surprisingly, I'm having trouble to figure out how to determine,
> that in Linux 64-bit OS, I'm building a project with -m32 specified.
> IOW, any CMake variable or macro to tell me target architecture
> of a build that is being configured is 32 or 64 bit?

Does this help?

include(CheckSymbolExists)

if(WIN32)
  check_symbol_exists("_M_AMD64" "" RTC_ARCH_X64)
  if(NOT RTC_ARCH_X64)
    check_symbol_exists("_M_IX86" "" RTC_ARCH_X86)
  endif(NOT RTC_ARCH_X64)
  # add check for arm here
  # see http://msdn.microsoft.com/en-us/library/b0084kay.aspx
else(WIN32)
  check_symbol_exists("__i386__" "" RTC_ARCH_X86)
  check_symbol_exists("__x86_64__" "" RTC_ARCH_X64)
  check_symbol_exists("__arm__" "" RTC_ARCH_ARM)
endif(WIN32)


-Gregor