print "Using GNU tools configuration"

Import('defenv')

### workarounds

# patch #1184316 for SCons
# http://sourceforge.net/tracker/?func=detail&aid=1184316&group_id=30337&atid=398973
defenv['RCCOM'] = '$RC $RCINCFLAGS $RCINCPREFIX $SOURCE.dir $RCFLAGS -i $SOURCE -o $TARGET'

### cross compiling

def cross_env(env):
	if env['PLATFORM'] != 'win32'
		env.Tool('crossmingw', toolpath = ['../Tools'])

### flags

defenv['ENTRY_FLAG'] = lambda x: '-Wl,-e,_' + x + '@16'
defenv['MAP_FLAG'] = lambda x: '-Wl,-Map,' + x + '.map'
defenv['EXCEPTION_FLAG'] = ''
defenv['NODEFLIBS_FLAG'] = '-nostdlib -Wl,--exclude-libs,msvcrt.a'
defenv['C_FLAG'] = '-x c'
defenv['CPP_FLAG'] = '-x c++'
defenv['ALIGN_FLAG'] = '-Wl,--file-alignment,512'

### debug

if defenv['DEBUG']:
	defenv.Append(CCFLAGS = '-g')

### stub environment

stub_env = defenv.Copy()
cross_env(stub_env)

stub_env.Append(CCFLAGS = '-Os')                  # optimize for size
stub_env.Append(CCFLAGS = '-Wall')                # all warnings
stub_env.Append(CCFLAGS = '-x c')                 # force compile as c

stub_env.Append(LINKFLAGS = '-s')                 # strip
stub_env.Append(LINKFLAGS = '-mwindows')          # build windows executables
stub_env.Append(LINKFLAGS = '$NODEFLIBS_FLAG')    # no standard libraries
stub_env.Append(LINKFLAGS = '$ALIGN_FLAG')        # 512 bytes align
stub_env.Append(LINKFLAGS = '-Wl,-e,_WinMain@16') # entry point

### makensis environment

makensis_env = defenv.Copy()

makensis_env.Append(CCFLAGS = '-O2')              # optimize
makensis_env.Append(CCFLAGS = '-Wall')            # all warnings

makensis_env.Append(LINKFLAGS = '-s')             # strip

### plugin environment

plugin_env = defenv.Copy()
cross_env(plugin_env)

plugin_env.Append(CCFLAGS = '-Os')                # optimize for size
plugin_env.Append(CCFLAGS = '-Wall')              # level 3 warnings

plugin_env.Append(LINKFLAGS = '-s')               # strip
plugin_env.Append(LINKFLAGS = '$ALIGN_FLAG')      # 512 bytes align

### util environment

util_env = defenv.Copy()
cross_env(util_env)

util_env.Append(CCFLAGS = '-O2')                  # optimize
util_env.Append(CCFLAGS = '-Wall')                # all warnings

util_env.Append(LINKFLAGS = '-s')                 # strip
util_env.Append(LINKFLAGS = '-mwindows')          # build windows executables
util_env.Append(LINKFLAGS = '$ALIGN_FLAG')        # 512 bytes align


### weird GCC requirements

#
# GCC requires some functions from the CRT to be present, if certain
# operations are done. For example, if a small string is assigned to
# a larger buffer, GCC 3.4+ uses memset to fill the remaining of the
# buffer with zeros.
#

funcs_file = None
funcs_obj = None

def check_requirement(ctx, func, trigger):
	ctx.Message('Checking for %s requirement... ' % func)

	flags = ctx.env['LINKFLAGS']

	ctx.env.Append(LINKFLAGS = '$NODEFLIBS_FLAG')
	ctx.env.Append(LINKFLAGS = '-Wl,-e,___main')

	test = """
		int __main() {
			%s
			return 0;
		}
	""" % trigger

	ret = not ctx.TryLink(test, '.c')
	ctx.Result(ret)

	ctx.env['LINKFLAGS'] = flags

	return ret

def replace_emitter(env, builder_name):
	builder = env['BUILDERS'][builder_name]

	def new_emitter(target, source, env):
		res = builder.emitter(target, source, env)

		if '$NODEFLIBS_FLAG' not in env['LINKFLAGS']:
			return res

		global funcs_file, funcs_obj

		if not funcs_obj:
			funcs_obj = env.SharedObject(funcs_file)
		res[1].append(funcs_obj)

		return res

	env['BUILDERS'][builder_name] = Builder(
		action = builder.action,
		prefix = builder.prefix,
		suffix = builder.suffix,
		src_suffix = builder.src_suffix,
		target_scanner = builder.target_scanner,
		source_scanner = builder.source_scanner,
		target_factory = builder.target_factory,
		source_factory = builder.source_factory,
		emitter = new_emitter, # only thing being replaced
		src_builder = builder.src_builder,
		single_source = builder.single_source
	)

def add_func(func):
	global funcs_file

	if not funcs_file:
		import os
		funcs_file = File('#.sconf_temp/funcs.c')
		try:
			os.unlink(funcs_file.abspath)
		except OSError:
			pass

	f = file(funcs_file.abspath, 'a')
	f.write(func)
	f.write('\n')
	f.close()

conf = defenv.Configure(custom_tests = { 'CheckRequirement' : check_requirement })

if conf.CheckRequirement('memcpy', 'struct s { char c[128]; } t = { "test" };'):
	add_func("""
	  #include <stdlib.h> // for size_t
		void *memcpy(void *out, const void *in, size_t len)
		{
			char *c_out=(char*)out;
			char *c_in=(char *)in;
			while (len-- > 0)
			{
				*c_out++=*c_in++;
			}
			return out;
		}
	""")

if conf.CheckRequirement('memset', 'char c[128] = "test";'):
	add_func("""
	  #include <stdlib.h> // for size_t
		void *memset(void *mem, int c, size_t len)
		{
			char *p=(char*)mem;
			while (len-- > 0)
			{
				*p++=c;
			}
			return mem;
		}
	""")

if funcs_file:
	replace_emitter(stub_env, 'Program')
	replace_emitter(plugin_env, 'SharedLibrary')
	replace_emitter(util_env, 'Program')

conf.Finish()

### return

Return('stub_env makensis_env plugin_env util_env')