SConstruct

   1 import os.path
   2
   3 opts = Options('scache.conf')
   4 ### These options are global defaults.
   5 ### If you want to change your options locally,
   6 ### give them to SCons on the command line, or
   7 ### edit scache.conf. Don't edit them here.
   8 opts.AddOptions(
   9     ('CC', 'Set the C compiler to use'),
  10     ('AS', 'Set the NASM executable name'),
  11     ('LINK', 'Set the linker to use'),
  12     ('CFLAGS', 'Set the C compiler flags', '-ffreestanding -m32 -O3 -Wall -std=c99 -pedantic'),
  13     ('ASFLAGS', 'Set the assembler flags', ''),
  14     ('LINKFLAGS', 'Set the linker flags', '-ffreestanding -nostdlib -Wl,--gc-sections,-m,elf_i386'),
  15     ('BUILDDIR', 'Set the sub-directory to put object files in', 'build'),
  16     BoolOption('verbose', 'Show full commands during the build process', False),
  17 )
  18
  19 env = Environment(options = opts, tools=['default', 'nasm'])
  20 Help(opts.GenerateHelpText(env))
  21 opts.Save('scache.conf', env)
  22
  23 class OurTests:
  24     def check_nasm32(context):
  25         """check whether nasm uses -f elf or -f elf32"""
  26         context.Message('Checking for nasm -f elf32... ')
  27         context.env['ASFLAGS'] = '-f elf32'
  28         result = context.TryCompile('', '.asm')
  29         context.Result(result)
  30         return result
  31
  32     def check_stack_prot(context):
  33         """check whether gcc supports -fno-stack-protector"""
  34         context.Message('Checking for -fno-stack-protector... ')
  35         context.env['CFLAGS'] = '-fno-stack-protector'
  36         result = context.TryCompile('', '.c')
  37         context.Result(result)
  38         return result
  39
  40 old_env = env.Clone()
  41
  42 if not env.GetOption('clean'):
  43     ### RUN TESTS AND CONFIGURE ENVIRONMENT ###
  44     conf = Configure(env, custom_tests = OurTests.__dict__)
  45
  46     # Does NASM want '-f elf' or '-f elf32' ?
  47     if conf.check_nasm32():
  48         env['ASFLAGS'] = old_env['ASFLAGS'] + ' -f elf32'
  49     else:
  50         env['ASFLAGS'] = old_env['ASFLAGS'] + ' -f elf'
  51
  52     # If the compiler has -fno-stack-protector, we need to disable
  53     # it to stop gcc inserting stack protection code (which doesn't
  54     # work in a kernel)
  55     if conf.check_stack_prot():
  56         env['CFLAGS'] = old_env['CFLAGS'] + ' -fno-stack-protector'
  57     else:
  58         env['CFLAGS'] = old_env['CFLAGS']
  59
  60     env = conf.Finish()
  61
  62 # set nice pretty messages
  63 if not env['verbose']:
  64     env['CCCOMSTR'] =     '     Compiling \e[32m$TARGET\e[0m'
  65     env['ASCOMSTR'] =     '    Assembling \e[32m$TARGET\e[0m'
  66     env['LINKCOMSTR'] =   '       Linking \e[32m$TARGET\e[0m'
  67     env['ARCOMSTR'] =     '     Archiving \e[32m$TARGET\e[0m'
  68     env['RANLIBCOMSTR'] = '      Indexing \e[32m$TARGET\e[0m'
  69     env['NMCOMSTR'] =     '  Creating map \e[32m$TARGET\e[0m'
  70
  71 SConscript('SConscript',
  72     exports = ['env'],
  73     build_dir = env['BUILDDIR'],
  74     duplicate = 0)
  75
  76 # clean config data
  77 env.Clean('.', ['config.log', '.sconf_temp'])