"""gallium
Frontend-tool for Gallium3D architecture.
"""
#
# Copyright 2008 VMware, Inc.
# All Rights Reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sub license, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice (including the
# next paragraph) shall be included in all copies or substantial portions
# of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
# IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
# ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
import distutils.version
import os
import os.path
import re
import subprocess
import platform as host_platform
import sys
import tempfile
import SCons.Action
import SCons.Builder
import SCons.Scanner
def symlink(target, source, env):
target = str(target[0])
source = str(source[0])
if os.path.islink(target) or os.path.exists(target):
os.remove(target)
os.symlink(os.path.basename(source), target)
def install(env, source, subdir):
target_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'], subdir)
return env.Install(target_dir, source)
def install_program(env, source):
return install(env, source, 'bin')
def install_shared_library(env, sources, version = ()):
targets = []
install_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'])
version = tuple(map(str, version))
if env['SHLIBSUFFIX'] == '.dll':
dlls = env.FindIxes(sources, 'SHLIBPREFIX', 'SHLIBSUFFIX')
targets += install(env, dlls, 'bin')
libs = env.FindIxes(sources, 'LIBPREFIX', 'LIBSUFFIX')
targets += install(env, libs, 'lib')
else:
for source in sources:
target_dir = os.path.join(install_dir, 'lib')
target_name = '.'.join((str(source),) + version)
last = env.InstallAs(os.path.join(target_dir, target_name), source)
targets += last
while len(version):
version = version[:-1]
target_name = '.'.join((str(source),) + version)
action = SCons.Action.Action(symlink, " Symlinking $TARGET ...")
last = env.Command(os.path.join(target_dir, target_name), last, action)
targets += last
return targets
def createInstallMethods(env):
env.AddMethod(install_program, 'InstallProgram')
env.AddMethod(install_shared_library, 'InstallSharedLibrary')
def msvc2013_compat(env):
if env['gcc']:
env.Append(CCFLAGS = [
'-Werror=vla',
'-Werror=pointer-arith',
])
def msvc2008_compat(env):
msvc2013_compat(env)
if env['gcc']:
env.Append(CFLAGS = [
'-Werror=declaration-after-statement',
])
def createMSVCCompatMethods(env):
env.AddMethod(msvc2013_compat, 'MSVC2013Compat')
env.AddMethod(msvc2008_compat, 'MSVC2008Compat')
def num_jobs():
try:
return int(os.environ['NUMBER_OF_PROCESSORS'])
except (ValueError, KeyError):
pass
try:
return os.sysconf('SC_NPROCESSORS_ONLN')
except (ValueError, OSError, AttributeError):
pass
try:
return int(os.popen2("sysctl -n hw.ncpu")[1].read())
except ValueError:
pass
return 1
def check_cc(env, cc, expr, cpp_opt = '-E'):
# Invoke C-preprocessor to determine whether the specified expression is
# true or not.
sys.stdout.write('Checking for %s ... ' % cc)
source = tempfile.NamedTemporaryFile(suffix='.c', delete=False)
source.write('#if !(%s)\n#error\n#endif\n' % expr)
source.close()
pipe = SCons.Action._subproc(env, [env['CC'], cpp_opt, source.name],
stdin = 'devnull',
stderr = 'devnull',
stdout = 'devnull')
result = pipe.wait() == 0
os.unlink(source.name)
sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
return result
def check_prog(env, prog):
"""Check whether this program exists."""
sys.stdout.write('Checking for %s ... ' % prog)
result = env.Detect(prog)
sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
return result
def generate(env):
"""Common environment generation code"""
# Tell tools which machine to compile for
env['TARGET_ARCH'] = env['machine']
env['MSVS_ARCH'] = env['machine']
# Toolchain
platform = env['platform']
env.Tool(env['toolchain'])
# Allow override compiler and specify additional flags from environment
if os.environ.has_key('CC'):
env['CC'] = os.environ['CC']
# Update CCVERSION to match
pipe = SCons.Action._subproc(env, [env['CC'], '--version'],
stdin = 'devnull',
stderr = 'devnull',
stdout = subprocess.PIPE)
if pipe.wait() == 0:
line = pipe.stdout.readline()
match = re.search(r'[0-9]+(\.[0-9]+)+', line)
if match:
env['CCVERSION'] = match.group(0)
if os.environ.has_key('CFLAGS'):
env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
if os.environ.has_key('CXX'):
env['CXX'] = os.environ['CXX']
if os.environ.has_key('CXXFLAGS'):
env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
if os.environ.has_key('LDFLAGS'):
env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])
# Detect gcc/clang not by executable name, but through pre-defined macros
# as autoconf does, to avoid drawing wrong conclusions when using tools
# that overrice CC/CXX like scan-build.
env['gcc'] = 0
env['clang'] = 0
env['msvc'] = 0
if host_platform.system() == 'Windows':
env['msvc'] = check_cc(env, 'MSVC', 'defined(_MSC_VER)', '/E')
if not env['msvc']:
env['gcc'] = check_cc(env, 'GCC', 'defined(__GNUC__) && !defined(__clang__)')
env['clang'] = check_cc(env, 'Clang', '__clang__')
env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
env['icc'] = 'icc' == os.path.basename(env['CC'])
if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
# MSVC x64 support is broken in earlier versions of scons
env.EnsurePythonVersion(2, 0)
# shortcuts
machine = env['machine']
platform = env['platform']
x86 = env['machine'] == 'x86'
ppc = env['machine'] == 'ppc'
gcc_compat = env['gcc'] or env['clang']
msvc = env['msvc']
suncc = env['suncc']
icc = env['icc']
# Determine whether we are cross compiling; in particular, whether we need
# to compile code generators with a different compiler as the target code.
hosthost_platform = host_platform.system().lower()
if hosthost_platform.startswith('cygwin'):
hosthost_platform = 'cygwin'
host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', host_platform.machine()))
host_machine = {
'x86': 'x86',
'i386': 'x86',
'i486': 'x86',
'i586': 'x86',
'i686': 'x86',
'ppc' : 'ppc',
'AMD64': 'x86_64',
'x86_64': 'x86_64',
}.get(host_machine, 'generic')
env['crosscompile'] = platform != hosthost_platform
if machine == 'x86_64' and host_machine != 'x86_64':
env['crosscompile'] = True
env['hostonly'] = False
# Backwards compatability with the debug= profile= options
if env['build'] == 'debug':
if not env['debug']:
print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
print
print ' scons build=release'
print
env['build'] = 'release'
if env['profile']:
print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
print
print ' scons build=profile'
print
env['build'] = 'profile'
if False:
# Enforce SConscripts to use the new build variable
env.popitem('debug')
env.popitem('profile')
else:
# Backwards portability with older sconscripts
if env['build'] in ('debug', 'checked'):
env['debug'] = True
env['profile'] = False
if env['build'] == 'profile':
env['debug'] = False
env['profile'] = True
if env['build'] == 'release':
env['debug'] = False
env['profile'] = False
# Put build output in a separate dir, which depends on the current
# configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
build_topdir = 'build'
build_subdir = env['platform']
if env['embedded']:
build_subdir = 'embedded-' + build_subdir
if env['machine'] != 'generic':
build_subdir += '-' + env['machine']
if env['build'] != 'release':
build_subdir += '-' + env['build']
build_dir = os.path.join(build_topdir, build_subdir)
# Place the .sconsign file in the build dir too, to avoid issues with
# different scons versions building the same source file
env['build_dir'] = build_dir
env.SConsignFile(os.path.join(build_dir, '.sconsign'))
if 'SCONS_CACHE_DIR' in os.environ:
print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
env.CacheDir(os.environ['SCONS_CACHE_DIR'])
env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')
# Parallel build
if env.GetOption('num_jobs') <= 1:
env.SetOption('num_jobs', num_jobs())
env.Decider('MD5-timestamp')
env.SetOption('max_drift', 60)
# C preprocessor options
cppdefines = []
if env['build'] in ('debug', 'checked'):
cppdefines += ['DEBUG']
else:
cppdefines += ['NDEBUG']
if env['build'] == 'profile':
cppdefines += ['PROFILE']
if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
cppdefines += [
'_POSIX_SOURCE',
('_POSIX_C_SOURCE', '199309L'),
'_SVID_SOURCE',
'_BSD_SOURCE',
'_GNU_SOURCE',
'_DEFAULT_SOURCE',
'HAVE_PTHREAD',
'HAVE_POSIX_MEMALIGN',
]
if env['platform'] == 'darwin':
cppdefines += [
'_DARWIN_C_SOURCE',
'GLX_USE_APPLEGL',
'GLX_DIRECT_RENDERING',
]
else:
cppdefines += [
'GLX_DIRECT_RENDERING',
'GLX_INDIRECT_RENDERING',
]
if env['platform'] in ('linux', 'freebsd'):
cppdefines += ['HAVE_ALIAS']
else:
cppdefines += ['GLX_ALIAS_UNSUPPORTED']
if env['platform'] in ('linux', 'darwin'):
cppdefines += ['HAVE_XLOCALE_H']
if env['platform'] == 'haiku':
cppdefines += [
'HAVE_PTHREAD',
'HAVE_POSIX_MEMALIGN'
]
if platform == 'windows':
cppdefines += [
'WIN32',
'_WINDOWS',
#'_UNICODE',
#'UNICODE',
# http://msdn.microsoft.com/en-us/library/aa383745.aspx
('_WIN32_WINNT', '0x0601'),
('WINVER', '0x0601'),
]
if gcc_compat:
cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
if msvc:
cppdefines += [
'VC_EXTRALEAN',
'_USE_MATH_DEFINES',
'_CRT_SECURE_NO_WARNINGS',
'_CRT_SECURE_NO_DEPRECATE',
'_SCL_SECURE_NO_WARNINGS',
'_SCL_SECURE_NO_DEPRECATE',
'_ALLOW_KEYWORD_MACROS',
'_HAS_EXCEPTIONS=0', # Tell C++ STL to not use exceptions
]
if env['build'] in ('debug', 'checked'):
cppdefines += ['_DEBUG']
if platform == 'windows':
cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
if env['embedded']:
cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
if env['texture_float']:
print 'warning: Floating-point textures enabled.'
print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
cppdefines += ['TEXTURE_FLOAT_ENABLED']
if gcc_compat:
ccversion = env['CCVERSION']
cppdefines += [
'HAVE___BUILTIN_EXPECT',
'HAVE___BUILTIN_FFS',
'HAVE___BUILTIN_FFSLL',
'HAVE_FUNC_ATTRIBUTE_FLATTEN',
'HAVE_FUNC_ATTRIBUTE_UNUSED',
# GCC 3.0
'HAVE_FUNC_ATTRIBUTE_FORMAT',
'HAVE_FUNC_ATTRIBUTE_PACKED',
# GCC 3.4
'HAVE___BUILTIN_CTZ',
'HAVE___BUILTIN_POPCOUNT',
'HAVE___BUILTIN_POPCOUNTLL',
'HAVE___BUILTIN_CLZ',
'HAVE___BUILTIN_CLZLL',
]
if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.5'):
cppdefines += ['HAVE___BUILTIN_UNREACHABLE']
env.Append(CPPDEFINES = cppdefines)
# C compiler options
cflags = [] # C
cxxflags = [] # C++
ccflags = [] # C & C++
if gcc_compat:
ccversion = env['CCVERSION']
if env['build'] == 'debug':
ccflags += ['-O0']
elif env['gcc'] and ccversion.startswith('4.2.'):
# gcc 4.2.x optimizer is broken
print "warning: gcc 4.2.x optimizer is broken -- disabling optimizations"
ccflags += ['-O0']
else:
ccflags += ['-O3']
if env['gcc']:
# gcc's builtin memcmp is slower than glibc's
# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
ccflags += ['-fno-builtin-memcmp']
# Work around aliasing bugs - developers should comment this out
ccflags += ['-fno-strict-aliasing']
ccflags += ['-g']
if env['build'] in ('checked', 'profile'):
# See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
ccflags += [
'-fno-omit-frame-pointer',
]
if env['gcc']:
ccflags += ['-fno-optimize-sibling-calls']
if env['machine'] == 'x86':
ccflags += [
'-m32',
#'-march=pentium4',
]
if platform != 'haiku':
# NOTE: We need to ensure stack is realigned given that we
# produce shared objects, and have no control over the stack
# alignment policy of the application. Therefore we need
# -mstackrealign ore -mincoming-stack-boundary=2.
#
# XXX: We could have SSE without -mstackrealign if we always used
# __attribute__((force_align_arg_pointer)), but that's not
# always the case.
ccflags += [
'-mstackrealign', # ensure stack is aligned
'-msse', '-msse2', # enable SIMD intrinsics
'-mfpmath=sse', # generate SSE floating-point arithmetic
]
if platform in ['windows', 'darwin']:
# Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
ccflags += ['-fno-common']
if platform in ['haiku']:
# Make optimizations compatible with Pentium or higher on Haiku
ccflags += [
'-mstackrealign', # ensure stack is aligned
'-march=i586', # Haiku target is Pentium
'-mtune=i686' # use i686 where we can
]
if env['machine'] == 'x86_64':
ccflags += ['-m64']
if platform == 'darwin':
ccflags += ['-fno-common']
if env['platform'] not in ('cygwin', 'haiku', 'windows'):
ccflags += ['-fvisibility=hidden']
# See also:
# - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
ccflags += [
'-Wall',
'-Wno-long-long',
'-fmessage-length=0', # be nice to Eclipse
]
cflags += [
'-Wmissing-prototypes',
'-std=gnu99',
]
if icc:
cflags += [
'-std=gnu99',
]
if msvc:
# See also:
# - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
# - cl /?
if 'MSVC_VERSION' not in env or distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('12.0'):
# Use bundled stdbool.h and stdint.h headers for older MSVC
# versions. stdint.h was introduced in MSVC 2010, but stdbool.h
# was only introduced in MSVC 2013.
top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
env.Append(CPPPATH = [os.path.join(top_dir, 'include/c99')])
if env['build'] == 'debug':
ccflags += [
'/Od', # disable optimizations
'/Oi', # enable intrinsic functions
]
else:
if 'MSVC_VERSION' in env and distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('11.0'):
print 'scons: warning: Visual Studio versions prior to 2012 are known to produce incorrect code when optimizations are enabled ( https://bugs.freedesktop.org/show_bug.cgi?id=58718 )'
ccflags += [
'/O2', # optimize for speed
]
if env['build'] == 'release':
ccflags += [
'/GL', # enable whole program optimization
]
else:
ccflags += [
'/Oy-', # disable frame pointer omission
'/GL-', # disable whole program optimization
]
ccflags += [
'/W3', # warning level
'/wd4018', # signed/unsigned mismatch
'/wd4056', # overflow in floating-point constant arithmetic
'/wd4244', # conversion from 'type1' to 'type2', possible loss of data
'/wd4267', # 'var' : conversion from 'size_t' to 'type', possible loss of data
'/wd4305', # truncation from 'type1' to 'type2'
'/wd4351', # new behavior: elements of array 'array' will be default initialized
'/wd4756', # overflow in constant arithmetic
'/wd4800', # forcing value to bool 'true' or 'false' (performance warning)
'/wd4996', # disable deprecated POSIX name warnings
]
if env['machine'] == 'x86':
ccflags += [
'/arch:SSE2', # use the SSE2 instructions (default since MSVC 2012)
]
if platform == 'windows':
ccflags += [
# TODO
]
# Automatic pdb generation
# See http://scons.tigris.org/issues/show_bug.cgi?id=1656
env.EnsureSConsVersion(0, 98, 0)
env['PDB'] = '${TARGET.base}.pdb'
env.Append(CCFLAGS = ccflags)
env.Append(CFLAGS = cflags)
env.Append(CXXFLAGS = cxxflags)
if env['platform'] == 'windows' and msvc:
# Choose the appropriate MSVC CRT
# http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
if env['build'] in ('debug', 'checked'):
env.Append(CCFLAGS = ['/MTd'])
env.Append(SHCCFLAGS = ['/LDd'])
else:
env.Append(CCFLAGS = ['/MT'])
env.Append(SHCCFLAGS = ['/LD'])
# Static code analysis
if env['analyze']:
if env['msvc']:
# http://msdn.microsoft.com/en-us/library/ms173498.aspx
env.Append(CCFLAGS = [
'/analyze',
#'/analyze:log', '${TARGET.base}.xml',
'/wd28251', # Inconsistent annotation for function
])
if env['clang']:
# scan-build will produce more comprehensive output
env.Append(CCFLAGS = ['--analyze'])
# Assembler options
if gcc_compat:
if env['machine'] == 'x86':
env.Append(ASFLAGS = ['-m32'])
if env['machine'] == 'x86_64':
env.Append(ASFLAGS = ['-m64'])
# Linker options
linkflags = []
shlinkflags = []
if gcc_compat:
if env['machine'] == 'x86':
linkflags += ['-m32']
if env['machine'] == 'x86_64':
linkflags += ['-m64']
if env['platform'] not in ('darwin'):
shlinkflags += [
'-Wl,-Bsymbolic',
]
# Handle circular dependencies in the libraries
if env['platform'] in ('darwin'):
pass
else:
env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
if env['platform'] == 'windows':
linkflags += [
'-Wl,--nxcompat', # DEP
'-Wl,--dynamicbase', # ASLR
]
# Avoid depending on gcc runtime DLLs
linkflags += ['-static-libgcc']
if 'w64' in env['CC'].split('-'):
linkflags += ['-static-libstdc++']
# Handle the @xx symbol munging of DLL exports
shlinkflags += ['-Wl,--enable-stdcall-fixup']
#shlinkflags += ['-Wl,--kill-at']
if msvc:
if env['build'] == 'release':
# enable Link-time Code Generation
linkflags += ['/LTCG']
env.Append(ARFLAGS = ['/LTCG'])
if platform == 'windows' and msvc:
# See also:
# - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
linkflags += [
'/fixed:no',
'/incremental:no',
'/dynamicbase', # ASLR
'/nxcompat', # DEP
]
env.Append(LINKFLAGS = linkflags)
env.Append(SHLINKFLAGS = shlinkflags)
# We have C++ in several libraries, so always link with the C++ compiler
if gcc_compat:
env['LINK'] = env['CXX']
# Default libs
libs = []
if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
libs += ['m', 'pthread', 'dl']
if env['platform'] in ('linux',):
libs += ['rt']
if env['platform'] in ('haiku'):
libs += ['root', 'be', 'network', 'translation']
env.Append(LIBS = libs)
# OpenMP
if env['openmp']:
if env['msvc']:
env.Append(CCFLAGS = ['/openmp'])
# When building openmp release VS2008 link.exe crashes with LNK1103 error.
# Workaround: overwrite PDB flags with empty value as it isn't required anyways
if env['build'] == 'release':
env['PDB'] = ''
if env['gcc']:
env.Append(CCFLAGS = ['-fopenmp'])
env.Append(LIBS = ['gomp'])
# Load tools
env.Tool('lex')
if env['msvc']:
env.Append(LEXFLAGS = [
# Force flex to use const keyword in prototypes, as relies on
# __cplusplus or __STDC__ macro to determine whether it's safe to
# use const keyword, but MSVC never defines __STDC__ unless we
# disable all MSVC extensions.
'-DYY_USE_CONST=',
])
# Flex relies on __STDC_VERSION__>=199901L to decide when to include
# C99 inttypes.h. We always have inttypes.h available with MSVC
# (either the one bundled with MSVC 2013, or the one we bundle
# ourselves), but we can't just define __STDC_VERSION__ without
# breaking stuff, as MSVC doesn't fully support C99. There's also no
# way to premptively include stdint.
env.Append(CCFLAGS = ['-FIinttypes.h'])
if host_platform.system() == 'Windows':
# Prefer winflexbison binaries, as not only they are easier to install
# (no additional dependencies), but also better Windows support.
if check_prog(env, 'win_flex'):
env["LEX"] = 'win_flex'
env.Append(LEXFLAGS = [
# windows compatibility (uses <io.h> instead of <unistd.h> and
# _isatty, _fileno functions)
'--wincompat'
])
env.Tool('yacc')
if host_platform.system() == 'Windows':
if check_prog(env, 'win_bison'):
env["YACC"] = 'win_bison'
if env['llvm']:
env.Tool('llvm')
# Custom builders and methods
env.Tool('custom')
createInstallMethods(env)
createMSVCCompatMethods(env)
env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage', 'xfixes', 'glproto >= 1.4.13'])
env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1', 'xcb-dri2 >= 1.8'])
env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
env.PkgCheckModules('DRM', ['libdrm >= 2.4.38'])
env.PkgCheckModules('UDEV', ['libudev >= 151'])
if env['x11']:
env.Append(CPPPATH = env['X11_CPPPATH'])
env['dri'] = env['x11'] and env['drm']
# for debugging
#print env.Dump()
def exists(env):
return 1