SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2004-2005 The Regents of The University of Michigan
   4 # All rights reserved.
   5 #
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions are
   8 # met: redistributions of source code must retain the above copyright
   9 # notice, this list of conditions and the following disclaimer;
  10 # redistributions in binary form must reproduce the above copyright
  11 # notice, this list of conditions and the following disclaimer in the
  12 # documentation and/or other materials provided with the distribution;
  13 # neither the name of the copyright holders nor the names of its
  14 # contributors may be used to endorse or promote products derived from
  15 # this software without specific prior written permission.
  16 #
  17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28 #
  29 # Authors: Steve Reinhardt
  30
  31 ###################################################
  32 #
  33 # SCons top-level build description (SConstruct) file.
  34 #
  35 # While in this directory ('m5'), just type 'scons' to build the default
  36 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
  37 # to build some other configuration (e.g., 'build/ALPHA_FS/m5.opt' for
  38 # the optimized full-system version).
  39 #
  40 # You can build M5 in a different directory as long as there is a
  41 # 'build/<CONFIG>' somewhere along the target path.  The build system
  42 # expects that all configs under the same build directory are being
  43 # built for the same host system.
  44 #
  45 # Examples:
  46 #
  47 #   The following two commands are equivalent.  The '-u' option tells
  48 #   scons to search up the directory tree for this SConstruct file.
  49 #   % cd <path-to-src>/m5 ; scons build/ALPHA_FS/m5.debug
  50 #   % cd <path-to-src>/m5/build/ALPHA_FS; scons -u m5.debug
  51 #
  52 #   The following two commands are equivalent and demonstrate building
  53 #   in a directory outside of the source tree.  The '-C' option tells
  54 #   scons to chdir to the specified directory to find this SConstruct
  55 #   file.
  56 #   % cd <path-to-src>/m5 ; scons /local/foo/build/ALPHA_FS/m5.debug
  57 #   % cd /local/foo/build/ALPHA_FS; scons -C <path-to-src>/m5 m5.debug
  58 #
  59 # You can use 'scons -H' to print scons options.  If you're in this
  60 # 'm5' directory (or use -u or -C to tell scons where to find this
  61 # file), you can use 'scons -h' to print all the M5-specific build
  62 # options as well.
  63 #
  64 ###################################################
  65
  66 # Python library imports
  67 import sys
  68 import os
  69 from os.path import join as joinpath
  70
  71 # Check for recent-enough Python and SCons versions.  If your system's
  72 # default installation of Python is not recent enough, you can use a
  73 # non-default installation of the Python interpreter by either (1)
  74 # rearranging your PATH so that scons finds the non-default 'python'
  75 # first or (2) explicitly invoking an alternative interpreter on the
  76 # scons script, e.g., "/usr/local/bin/python2.4 `which scons` [args]".
  77 EnsurePythonVersion(2,4)
  78
  79 # Ironically, SCons 0.96 dies if you give EnsureSconsVersion a
  80 # 3-element version number.
  81 min_scons_version = (0,96,91)
  82 try:
  83     EnsureSConsVersion(*min_scons_version)
  84 except:
  85     print "Error checking current SCons version."
  86     print "SCons", ".".join(map(str,min_scons_version)), "or greater required."
  87     Exit(2)
  88
  89
  90 # The absolute path to the current directory (where this file lives).
  91 ROOT = Dir('.').abspath
  92
  93 # Path to the M5 source tree.
  94 SRCDIR = joinpath(ROOT, 'src')
  95
  96 # tell python where to find m5 python code
  97 sys.path.append(joinpath(ROOT, 'src/python'))
  98
  99 ###################################################
 100 #
 101 # Figure out which configurations to set up based on the path(s) of
 102 # the target(s).
 103 #
 104 ###################################################
 105
 106 # Find default configuration & binary.
 107 Default(os.environ.get('M5_DEFAULT_BINARY', 'build/ALPHA_SE/m5.debug'))
 108
 109 # helper function: find last occurrence of element in list
 110 def rfind(l, elt, offs = -1):
 111     for i in range(len(l)+offs, 0, -1):
 112         if l[i] == elt:
 113             return i
 114     raise ValueError, "element not found"
 115
 116 # helper function: compare dotted version numbers.
 117 # E.g., compare_version('1.3.25', '1.4.1')
 118 # returns -1, 0, 1 if v1 is <, ==, > v2
 119 def compare_versions(v1, v2):
 120     # Convert dotted strings to lists
 121     v1 = map(int, v1.split('.'))
 122     v2 = map(int, v2.split('.'))
 123     # Compare corresponding elements of lists
 124     for n1,n2 in zip(v1, v2):
 125         if n1 < n2: return -1
 126         if n1 > n2: return  1
 127     # all corresponding values are equal... see if one has extra values
 128     if len(v1) < len(v2): return -1
 129     if len(v1) > len(v2): return  1
 130     return 0
 131
 132 # Each target must have 'build' in the interior of the path; the
 133 # directory below this will determine the build parameters.  For
 134 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 135 # recognize that ALPHA_SE specifies the configuration because it
 136 # follow 'build' in the bulid path.
 137
 138 # Generate absolute paths to targets so we can see where the build dir is
 139 if COMMAND_LINE_TARGETS:
 140     # Ask SCons which directory it was invoked from
 141     launch_dir = GetLaunchDir()
 142     # Make targets relative to invocation directory
 143     abs_targets = map(lambda x: os.path.normpath(joinpath(launch_dir, str(x))),
 144                       COMMAND_LINE_TARGETS)
 145 else:
 146     # Default targets are relative to root of tree
 147     abs_targets = map(lambda x: os.path.normpath(joinpath(ROOT, str(x))),
 148                       DEFAULT_TARGETS)
 149
 150
 151 # Generate a list of the unique build roots and configs that the
 152 # collected targets reference.
 153 build_paths = []
 154 build_root = None
 155 for t in abs_targets:
 156     path_dirs = t.split('/')
 157     try:
 158         build_top = rfind(path_dirs, 'build', -2)
 159     except:
 160         print "Error: no non-leaf 'build' dir found on target path", t
 161         Exit(1)
 162     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 163     if not build_root:
 164         build_root = this_build_root
 165     else:
 166         if this_build_root != build_root:
 167             print "Error: build targets not under same build root\n"\
 168                   "  %s\n  %s" % (build_root, this_build_root)
 169             Exit(1)
 170     build_path = joinpath('/',*path_dirs[:build_top+2])
 171     if build_path not in build_paths:
 172         build_paths.append(build_path)
 173
 174 ###################################################
 175 #
 176 # Set up the default build environment.  This environment is copied
 177 # and modified according to each selected configuration.
 178 #
 179 ###################################################
 180
 181 env = Environment(ENV = os.environ,  # inherit user's environment vars
 182                   ROOT = ROOT,
 183                   SRCDIR = SRCDIR)
 184
 185 #Parse CC/CXX early so that we use the correct compiler for
 186 # to test for dependencies/versions/libraries/includes
 187 if ARGUMENTS.get('CC', None):
 188     env['CC'] = ARGUMENTS.get('CC')
 189
 190 if ARGUMENTS.get('CXX', None):
 191     env['CXX'] = ARGUMENTS.get('CXX')
 192
 193 env.SConsignFile(joinpath(build_root,"sconsign"))
 194
 195 # Default duplicate option is to use hard links, but this messes up
 196 # when you use emacs to edit a file in the target dir, as emacs moves
 197 # file to file~ then copies to file, breaking the link.  Symbolic
 198 # (soft) links work better.
 199 env.SetOption('duplicate', 'soft-copy')
 200
 201 # I waffle on this setting... it does avoid a few painful but
 202 # unnecessary builds, but it also seems to make trivial builds take
 203 # noticeably longer.
 204 if False:
 205     env.TargetSignatures('content')
 206
 207 # M5_PLY is used by isa_parser.py to find the PLY package.
 208 env.Append(ENV = { 'M5_PLY' : Dir('ext/ply') })
 209
 210 # Set up default C++ compiler flags
 211 env.Append(CCFLAGS='-pipe')
 212 env.Append(CCFLAGS='-fno-strict-aliasing')
 213 env.Append(CCFLAGS=Split('-Wall -Wno-sign-compare -Werror -Wundef'))
 214 if sys.platform == 'cygwin':
 215     # cygwin has some header file issues...
 216     env.Append(CCFLAGS=Split("-Wno-uninitialized"))
 217 env.Append(CPPPATH=[Dir('ext/dnet')])
 218
 219 # Check for SWIG
 220 if not env.has_key('SWIG'):
 221     print 'Error: SWIG utility not found.'
 222     print '       Please install (see http://www.swig.org) and retry.'
 223     Exit(1)
 224
 225 # Check for appropriate SWIG version
 226 swig_version = os.popen('swig -version').read().split()
 227 # First 3 words should be "SWIG Version x.y.z"
 228 if swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
 229     print 'Error determining SWIG version.'
 230     Exit(1)
 231
 232 min_swig_version = '1.3.28'
 233 if compare_versions(swig_version[2], min_swig_version) < 0:
 234     print 'Error: SWIG version', min_swig_version, 'or newer required.'
 235     print '       Installed version:', swig_version[2]
 236     Exit(1)
 237
 238 # Set up SWIG flags & scanner
 239 env.Append(SWIGFLAGS=Split('-c++ -python -modern $_CPPINCFLAGS'))
 240
 241 import SCons.Scanner
 242
 243 swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
 244
 245 swig_scanner = SCons.Scanner.ClassicCPP("SwigScan", ".i", "CPPPATH",
 246                                         swig_inc_re)
 247
 248 env.Append(SCANNERS = swig_scanner)
 249
 250 # Platform-specific configuration.  Note again that we assume that all
 251 # builds under a given build root run on the same host platform.
 252 conf = Configure(env,
 253                  conf_dir = joinpath(build_root, '.scons_config'),
 254                  log_file = joinpath(build_root, 'scons_config.log'))
 255
 256 # Find Python include and library directories for embedding the
 257 # interpreter.  For consistency, we will use the same Python
 258 # installation used to run scons (and thus this script).  If you want
 259 # to link in an alternate version, see above for instructions on how
 260 # to invoke scons with a different copy of the Python interpreter.
 261
 262 # Get brief Python version name (e.g., "python2.4") for locating
 263 # include & library files
 264 py_version_name = 'python' + sys.version[:3]
 265
 266 # include path, e.g. /usr/local/include/python2.4
 267 py_header_path = joinpath(sys.exec_prefix, 'include', py_version_name)
 268 env.Append(CPPPATH = py_header_path)
 269 # verify that it works
 270 if not conf.CheckHeader('Python.h', '<>'):
 271     print "Error: can't find Python.h header in", py_header_path
 272     Exit(1)
 273
 274 # add library path too if it's not in the default place
 275 py_lib_path = None
 276 if sys.exec_prefix != '/usr':
 277     py_lib_path = joinpath(sys.exec_prefix, 'lib')
 278 elif sys.platform == 'cygwin':
 279     # cygwin puts the .dll in /bin for some reason
 280     py_lib_path = '/bin'
 281 if py_lib_path:
 282     env.Append(LIBPATH = py_lib_path)
 283     print 'Adding', py_lib_path, 'to LIBPATH for', py_version_name
 284 if not conf.CheckLib(py_version_name):
 285     print "Error: can't find Python library", py_version_name
 286     Exit(1)
 287
 288 # On Solaris you need to use libsocket for socket ops
 289 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 290    if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 291        print "Can't find library with socket calls (e.g. accept())"
 292        Exit(1)
 293
 294 # Check for zlib.  If the check passes, libz will be automatically
 295 # added to the LIBS environment variable.
 296 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++'):
 297     print 'Error: did not find needed zlib compression library '\
 298           'and/or zlib.h header file.'
 299     print '       Please install zlib and try again.'
 300     Exit(1)
 301
 302 # Check for <fenv.h> (C99 FP environment control)
 303 have_fenv = conf.CheckHeader('fenv.h', '<>')
 304 if not have_fenv:
 305     print "Warning: Header file <fenv.h> not found."
 306     print "         This host has no IEEE FP rounding mode control."
 307
 308 # Check for mysql.
 309 mysql_config = WhereIs('mysql_config')
 310 have_mysql = mysql_config != None
 311
 312 # Check MySQL version.
 313 if have_mysql:
 314     mysql_version = os.popen(mysql_config + ' --version').read()
 315     min_mysql_version = '4.1'
 316     if compare_versions(mysql_version, min_mysql_version) < 0:
 317         print 'Warning: MySQL', min_mysql_version, 'or newer required.'
 318         print '         Version', mysql_version, 'detected.'
 319         have_mysql = False
 320
 321 # Set up mysql_config commands.
 322 if have_mysql:
 323     mysql_config_include = mysql_config + ' --include'
 324     if os.system(mysql_config_include + ' > /dev/null') != 0:
 325         # older mysql_config versions don't support --include, use
 326         # --cflags instead
 327         mysql_config_include = mysql_config + ' --cflags | sed s/\\\'//g'
 328     # This seems to work in all versions
 329     mysql_config_libs = mysql_config + ' --libs'
 330
 331 env = conf.Finish()
 332
 333 # Define the universe of supported ISAs
 334 env['ALL_ISA_LIST'] = ['alpha', 'sparc', 'mips']
 335
 336 # Define the universe of supported CPU models
 337 env['ALL_CPU_LIST'] = ['AtomicSimpleCPU', 'TimingSimpleCPU',
 338                        'O3CPU', 'OzoneCPU']
 339
 340 if os.path.isdir(joinpath(SRCDIR, 'encumbered/cpu/full')):
 341     env['ALL_CPU_LIST'] += ['FullCPU']
 342
 343 # Sticky options get saved in the options file so they persist from
 344 # one invocation to the next (unless overridden, in which case the new
 345 # value becomes sticky).
 346 sticky_opts = Options(args=ARGUMENTS)
 347 sticky_opts.AddOptions(
 348     EnumOption('TARGET_ISA', 'Target ISA', 'alpha', env['ALL_ISA_LIST']),
 349     BoolOption('FULL_SYSTEM', 'Full-system support', False),
 350     # There's a bug in scons 0.96.1 that causes ListOptions with list
 351     # values (more than one value) not to be able to be restored from
 352     # a saved option file.  If this causes trouble then upgrade to
 353     # scons 0.96.90 or later.
 354     ListOption('CPU_MODELS', 'CPU models', 'AtomicSimpleCPU,TimingSimpleCPU,O3CPU',
 355                env['ALL_CPU_LIST']),
 356     BoolOption('ALPHA_TLASER',
 357                'Model Alpha TurboLaser platform (vs. Tsunami)', False),
 358     BoolOption('NO_FAST_ALLOC', 'Disable fast object allocator', False),
 359     BoolOption('EFENCE', 'Link with Electric Fence malloc debugger',
 360                False),
 361     BoolOption('SS_COMPATIBLE_FP',
 362                'Make floating-point results compatible with SimpleScalar',
 363                False),
 364     BoolOption('USE_SSE2',
 365                'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 366                False),
 367     BoolOption('USE_MYSQL', 'Use MySQL for stats output', have_mysql),
 368     BoolOption('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 369     BoolOption('USE_CHECKER', 'Use checker for detailed CPU models', False),
 370     ('CC', 'C compiler', os.environ.get('CC', env['CC'])),
 371     ('CXX', 'C++ compiler', os.environ.get('CXX', env['CXX'])),
 372     BoolOption('BATCH', 'Use batch pool for build and tests', False),
 373     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 374     ('PYTHONHOME',
 375      'Override the default PYTHONHOME for this system (use with caution)',
 376      '%s:%s' % (sys.prefix, sys.exec_prefix))
 377     )
 378
 379 # Non-sticky options only apply to the current build.
 380 nonsticky_opts = Options(args=ARGUMENTS)
 381 nonsticky_opts.AddOptions(
 382     BoolOption('update_ref', 'Update test reference outputs', False)
 383     )
 384
 385 # These options get exported to #defines in config/*.hh (see src/SConscript).
 386 env.ExportOptions = ['FULL_SYSTEM', 'ALPHA_TLASER', 'USE_FENV', \
 387                      'USE_MYSQL', 'NO_FAST_ALLOC', 'SS_COMPATIBLE_FP', \
 388                      'USE_CHECKER', 'PYTHONHOME', 'TARGET_ISA']
 389
 390 # Define a handy 'no-op' action
 391 def no_action(target, source, env):
 392     return 0
 393
 394 env.NoAction = Action(no_action, None)
 395
 396 ###################################################
 397 #
 398 # Define a SCons builder for configuration flag headers.
 399 #
 400 ###################################################
 401
 402 # This function generates a config header file that #defines the
 403 # option symbol to the current option setting (0 or 1).  The source
 404 # operands are the name of the option and a Value node containing the
 405 # value of the option.
 406 def build_config_file(target, source, env):
 407     (option, value) = [s.get_contents() for s in source]
 408     f = file(str(target[0]), 'w')
 409     print >> f, '#define', option, value
 410     f.close()
 411     return None
 412
 413 # Generate the message to be printed when building the config file.
 414 def build_config_file_string(target, source, env):
 415     (option, value) = [s.get_contents() for s in source]
 416     return "Defining %s as %s in %s." % (option, value, target[0])
 417
 418 # Combine the two functions into a scons Action object.
 419 config_action = Action(build_config_file, build_config_file_string)
 420
 421 # The emitter munges the source & target node lists to reflect what
 422 # we're really doing.
 423 def config_emitter(target, source, env):
 424     # extract option name from Builder arg
 425     option = str(target[0])
 426     # True target is config header file
 427     target = joinpath('config', option.lower() + '.hh')
 428     val = env[option]
 429     if isinstance(val, bool):
 430         # Force value to 0/1
 431         val = int(val)
 432     elif isinstance(val, str):
 433         val = '"' + val + '"'
 434
 435     # Sources are option name & value (packaged in SCons Value nodes)
 436     return ([target], [Value(option), Value(val)])
 437
 438 config_builder = Builder(emitter = config_emitter, action = config_action)
 439
 440 env.Append(BUILDERS = { 'ConfigFile' : config_builder })
 441
 442 ###################################################
 443 #
 444 # Define a SCons builder for copying files.  This is used by the
 445 # Python zipfile code in src/python/SConscript, but is placed up here
 446 # since it's potentially more generally applicable.
 447 #
 448 ###################################################
 449
 450 copy_builder = Builder(action = Copy("$TARGET", "$SOURCE"))
 451
 452 env.Append(BUILDERS = { 'CopyFile' : copy_builder })
 453
 454 ###################################################
 455 #
 456 # Define a simple SCons builder to concatenate files.
 457 #
 458 # Used to append the Python zip archive to the executable.
 459 #
 460 ###################################################
 461
 462 concat_builder = Builder(action = Action(['cat $SOURCES > $TARGET',
 463                                           'chmod +x $TARGET']))
 464
 465 env.Append(BUILDERS = { 'Concat' : concat_builder })
 466
 467
 468 # base help text
 469 help_text = '''
 470 Usage: scons [scons options] [build options] [target(s)]
 471
 472 '''
 473
 474 # libelf build is shared across all configs in the build root.
 475 env.SConscript('ext/libelf/SConscript',
 476                build_dir = joinpath(build_root, 'libelf'),
 477                exports = 'env')
 478
 479 ###################################################
 480 #
 481 # This function is used to set up a directory with switching headers
 482 #
 483 ###################################################
 484
 485 def make_switching_dir(dirname, switch_headers, env):
 486     # Generate the header.  target[0] is the full path of the output
 487     # header to generate.  'source' is a dummy variable, since we get the
 488     # list of ISAs from env['ALL_ISA_LIST'].
 489     def gen_switch_hdr(target, source, env):
 490         fname = str(target[0])
 491         basename = os.path.basename(fname)
 492         f = open(fname, 'w')
 493         f.write('#include "arch/isa_specific.hh"\n')
 494         cond = '#if'
 495         for isa in env['ALL_ISA_LIST']:
 496             f.write('%s THE_ISA == %s_ISA\n#include "%s/%s/%s"\n'
 497                     % (cond, isa.upper(), dirname, isa, basename))
 498             cond = '#elif'
 499         f.write('#else\n#error "THE_ISA not set"\n#endif\n')
 500         f.close()
 501         return 0
 502
 503     # String to print when generating header
 504     def gen_switch_hdr_string(target, source, env):
 505         return "Generating switch header " + str(target[0])
 506
 507     # Build SCons Action object. 'varlist' specifies env vars that this
 508     # action depends on; when env['ALL_ISA_LIST'] changes these actions
 509     # should get re-executed.
 510     switch_hdr_action = Action(gen_switch_hdr, gen_switch_hdr_string,
 511                                varlist=['ALL_ISA_LIST'])
 512
 513     # Instantiate actions for each header
 514     for hdr in switch_headers:
 515         env.Command(hdr, [], switch_hdr_action)
 516
 517 env.make_switching_dir = make_switching_dir
 518
 519 ###################################################
 520 #
 521 # Define build environments for selected configurations.
 522 #
 523 ###################################################
 524
 525 # rename base env
 526 base_env = env
 527
 528 for build_path in build_paths:
 529     print "Building in", build_path
 530     # build_dir is the tail component of build path, and is used to
 531     # determine the build parameters (e.g., 'ALPHA_SE')
 532     (build_root, build_dir) = os.path.split(build_path)
 533     # Make a copy of the build-root environment to use for this config.
 534     env = base_env.Copy()
 535
 536     # Set env options according to the build directory config.
 537     sticky_opts.files = []
 538     # Options for $BUILD_ROOT/$BUILD_DIR are stored in
 539     # $BUILD_ROOT/options/$BUILD_DIR so you can nuke
 540     # $BUILD_ROOT/$BUILD_DIR without losing your options settings.
 541     current_opts_file = joinpath(build_root, 'options', build_dir)
 542     if os.path.isfile(current_opts_file):
 543         sticky_opts.files.append(current_opts_file)
 544         print "Using saved options file %s" % current_opts_file
 545     else:
 546         # Build dir-specific options file doesn't exist.
 547
 548         # Make sure the directory is there so we can create it later
 549         opt_dir = os.path.dirname(current_opts_file)
 550         if not os.path.isdir(opt_dir):
 551             os.mkdir(opt_dir)
 552
 553         # Get default build options from source tree.  Options are
 554         # normally determined by name of $BUILD_DIR, but can be
 555         # overriden by 'default=' arg on command line.
 556         default_opts_file = joinpath('build_opts',
 557                                      ARGUMENTS.get('default', build_dir))
 558         if os.path.isfile(default_opts_file):
 559             sticky_opts.files.append(default_opts_file)
 560             print "Options file %s not found,\n  using defaults in %s" \
 561                   % (current_opts_file, default_opts_file)
 562         else:
 563             print "Error: cannot find options file %s or %s" \
 564                   % (current_opts_file, default_opts_file)
 565             Exit(1)
 566
 567     # Apply current option settings to env
 568     sticky_opts.Update(env)
 569     nonsticky_opts.Update(env)
 570
 571     help_text += "Sticky options for %s:\n" % build_dir \
 572                  + sticky_opts.GenerateHelpText(env) \
 573                  + "\nNon-sticky options for %s:\n" % build_dir \
 574                  + nonsticky_opts.GenerateHelpText(env)
 575
 576     # Process option settings.
 577
 578     if not have_fenv and env['USE_FENV']:
 579         print "Warning: <fenv.h> not available; " \
 580               "forcing USE_FENV to False in", build_dir + "."
 581         env['USE_FENV'] = False
 582
 583     if not env['USE_FENV']:
 584         print "Warning: No IEEE FP rounding mode control in", build_dir + "."
 585         print "         FP results may deviate slightly from other platforms."
 586
 587     if env['EFENCE']:
 588         env.Append(LIBS=['efence'])
 589
 590     if env['USE_MYSQL']:
 591         if not have_mysql:
 592             print "Warning: MySQL not available; " \
 593                   "forcing USE_MYSQL to False in", build_dir + "."
 594             env['USE_MYSQL'] = False
 595         else:
 596             print "Compiling in", build_dir, "with MySQL support."
 597             env.ParseConfig(mysql_config_libs)
 598             env.ParseConfig(mysql_config_include)
 599
 600     # Save sticky option settings back to current options file
 601     sticky_opts.Save(current_opts_file, env)
 602
 603     # Do this after we save setting back, or else we'll tack on an
 604     # extra 'qdo' every time we run scons.
 605     if env['BATCH']:
 606         env['CC']  = env['BATCH_CMD'] + ' ' + env['CC']
 607         env['CXX'] = env['BATCH_CMD'] + ' ' + env['CXX']
 608
 609     if env['USE_SSE2']:
 610         env.Append(CCFLAGS='-msse2')
 611
 612     # The src/SConscript file sets up the build rules in 'env' according
 613     # to the configured options.  It returns a list of environments,
 614     # one for each variant build (debug, opt, etc.)
 615     envList = SConscript('src/SConscript', build_dir = build_path,
 616                          exports = 'env')
 617
 618     # Set up the regression tests for each build.
 619     for e in envList:
 620         SConscript('tests/SConscript',
 621                    build_dir = joinpath(build_path, 'tests', e.Label),
 622                    exports = { 'env' : e }, duplicate = False)
 623
 624 Help(help_text)
 625
 626
 627 ###################################################
 628 #
 629 # Let SCons do its thing.  At this point SCons will use the defined
 630 # build environments to build the requested targets.
 631 #
 632 ###################################################
 633