SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2013, 2015-2020 ARM Limited
   4 # All rights reserved.
   5 #
   6 # The license below extends only to copyright in the software and shall
   7 # not be construed as granting a license to any other intellectual
   8 # property including but not limited to intellectual property relating
   9 # to a hardware implementation of the functionality of the software
  10 # licensed hereunder.  You may use the software subject to the license
  11 # terms below provided that you ensure that this notice is replicated
  12 # unmodified and in its entirety in all distributions of the software,
  13 # modified or unmodified, in source code or in binary form.
  14 #
  15 # Copyright (c) 2011 Advanced Micro Devices, Inc.
  16 # Copyright (c) 2009 The Hewlett-Packard Development Company
  17 # Copyright (c) 2004-2005 The Regents of The University of Michigan
  18 # All rights reserved.
  19 #
  20 # Redistribution and use in source and binary forms, with or without
  21 # modification, are permitted provided that the following conditions are
  22 # met: redistributions of source code must retain the above copyright
  23 # notice, this list of conditions and the following disclaimer;
  24 # redistributions in binary form must reproduce the above copyright
  25 # notice, this list of conditions and the following disclaimer in the
  26 # documentation and/or other materials provided with the distribution;
  27 # neither the name of the copyright holders nor the names of its
  28 # contributors may be used to endorse or promote products derived from
  29 # this software without specific prior written permission.
  30 #
  31 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42
  43 ###################################################
  44 #
  45 # SCons top-level build description (SConstruct) file.
  46 #
  47 # While in this directory ('gem5'), just type 'scons' to build the default
  48 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
  49 # to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
  50 # the optimized full-system version).
  51 #
  52 # You can build gem5 in a different directory as long as there is a
  53 # 'build/<CONFIG>' somewhere along the target path.  The build system
  54 # expects that all configs under the same build directory are being
  55 # built for the same host system.
  56 #
  57 # Examples:
  58 #
  59 #   The following two commands are equivalent.  The '-u' option tells
  60 #   scons to search up the directory tree for this SConstruct file.
  61 #   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
  62 #   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
  63 #
  64 #   The following two commands are equivalent and demonstrate building
  65 #   in a directory outside of the source tree.  The '-C' option tells
  66 #   scons to chdir to the specified directory to find this SConstruct
  67 #   file.
  68 #   % cd <path-to-src>/gem5 ; scons /local/foo/build/ALPHA/gem5.debug
  69 #   % cd /local/foo/build/ALPHA; scons -C <path-to-src>/gem5 gem5.debug
  70 #
  71 # You can use 'scons -H' to print scons options.  If you're in this
  72 # 'gem5' directory (or use -u or -C to tell scons where to find this
  73 # file), you can use 'scons -h' to print all the gem5-specific build
  74 # options as well.
  75 #
  76 ###################################################
  77
  78 from __future__ import print_function
  79
  80 # Global Python includes
  81 import itertools
  82 import os
  83 import re
  84 import shutil
  85 import subprocess
  86 import sys
  87
  88 from os import mkdir, environ
  89 from os.path import abspath, basename, dirname, expanduser, normpath
  90 from os.path import exists,  isdir, isfile
  91 from os.path import join as joinpath, split as splitpath
  92 from re import match
  93
  94 # SCons includes
  95 import SCons
  96 import SCons.Node
  97 import SCons.Node.FS
  98
  99 from m5.util import compareVersions, readCommand
 100
 101 help_texts = {
 102     "options" : "",
 103     "global_vars" : "",
 104     "local_vars" : ""
 105 }
 106
 107 Export("help_texts")
 108
 109
 110 # There's a bug in scons in that (1) by default, the help texts from
 111 # AddOption() are supposed to be displayed when you type 'scons -h'
 112 # and (2) you can override the help displayed by 'scons -h' using the
 113 # Help() function, but these two features are incompatible: once
 114 # you've overridden the help text using Help(), there's no way to get
 115 # at the help texts from AddOptions.  See:
 116 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 117 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 118 # This hack lets us extract the help text from AddOptions and
 119 # re-inject it via Help().  Ideally someday this bug will be fixed and
 120 # we can just use AddOption directly.
 121 def AddLocalOption(*args, **kwargs):
 122     col_width = 30
 123
 124     help = "  " + ", ".join(args)
 125     if "help" in kwargs:
 126         length = len(help)
 127         if length >= col_width:
 128             help += "\n" + " " * col_width
 129         else:
 130             help += " " * (col_width - length)
 131         help += kwargs["help"]
 132     help_texts["options"] += help + "\n"
 133
 134     AddOption(*args, **kwargs)
 135
 136 AddLocalOption('--colors', dest='use_colors', action='store_true',
 137                help="Add color to abbreviated scons output")
 138 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 139                help="Don't add color to abbreviated scons output")
 140 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 141                action='store_true',
 142                help="Build with support for C++-based configuration")
 143 AddLocalOption('--default', dest='default', type='string', action='store',
 144                help='Override which build_opts file to use for defaults')
 145 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 146                help='Disable style checking hooks')
 147 AddLocalOption('--gold-linker', dest='gold_linker', action='store_true',
 148                help='Use the gold linker')
 149 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 150                help='Disable Link-Time Optimization for fast')
 151 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 152                help='Use Link-Time Optimization instead of partial linking' +
 153                     ' when the compiler doesn\'t support using them together.')
 154 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 155                help='Update test reference outputs')
 156 AddLocalOption('--verbose', dest='verbose', action='store_true',
 157                help='Print full tool command lines')
 158 AddLocalOption('--without-python', dest='without_python',
 159                action='store_true',
 160                help='Build without Python configuration support')
 161 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 162                action='store_true',
 163                help='Disable linking against tcmalloc')
 164 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 165                help='Build with Undefined Behavior Sanitizer if available')
 166 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 167                help='Build with Address Sanitizer if available')
 168
 169 from gem5_scons import Transform, error, warning
 170
 171 if GetOption('no_lto') and GetOption('force_lto'):
 172     error('--no-lto and --force-lto are mutually exclusive')
 173
 174 ########################################################################
 175 #
 176 # Set up the main build environment.
 177 #
 178 ########################################################################
 179
 180 main = Environment()
 181
 182 from gem5_scons.util import get_termcap
 183 termcap = get_termcap()
 184
 185 main_dict_keys = main.Dictionary().keys()
 186
 187 # Check that we have a C/C++ compiler
 188 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 189     error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 190
 191 ###################################################
 192 #
 193 # Figure out which configurations to set up based on the path(s) of
 194 # the target(s).
 195 #
 196 ###################################################
 197
 198 # Find default configuration & binary.
 199 Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
 200
 201 # helper function: find last occurrence of element in list
 202 def rfind(l, elt, offs = -1):
 203     for i in range(len(l)+offs, 0, -1):
 204         if l[i] == elt:
 205             return i
 206     raise ValueError("element not found")
 207
 208 # Take a list of paths (or SCons Nodes) and return a list with all
 209 # paths made absolute and ~-expanded.  Paths will be interpreted
 210 # relative to the launch directory unless a different root is provided
 211 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 212     return [abspath(joinpath(root, expanduser(str(p))))
 213             for p in path_list]
 214
 215 def find_first_prog(prog_names):
 216     """Find the absolute path to the first existing binary in prog_names"""
 217
 218     if not isinstance(prog_names, (list, tuple)):
 219         prog_names = [ prog_names ]
 220
 221     for p in prog_names:
 222         p = main.WhereIs(p)
 223         if p is not None:
 224             return p
 225
 226     return None
 227
 228 # Each target must have 'build' in the interior of the path; the
 229 # directory below this will determine the build parameters.  For
 230 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 231 # recognize that ALPHA_SE specifies the configuration because it
 232 # follow 'build' in the build path.
 233
 234 # The funky assignment to "[:]" is needed to replace the list contents
 235 # in place rather than reassign the symbol to a new list, which
 236 # doesn't work (obviously!).
 237 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 238
 239 # Generate a list of the unique build roots and configs that the
 240 # collected targets reference.
 241 variant_paths = []
 242 build_root = None
 243 for t in BUILD_TARGETS:
 244     path_dirs = t.split('/')
 245     try:
 246         build_top = rfind(path_dirs, 'build', -2)
 247     except:
 248         error("No non-leaf 'build' dir found on target path.", t)
 249     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 250     if not build_root:
 251         build_root = this_build_root
 252     else:
 253         if this_build_root != build_root:
 254             error("build targets not under same build root\n"
 255                   "  %s\n  %s" % (build_root, this_build_root))
 256     variant_path = joinpath('/',*path_dirs[:build_top+2])
 257     if variant_path not in variant_paths:
 258         variant_paths.append(variant_path)
 259
 260 # Make sure build_root exists (might not if this is the first build there)
 261 if not isdir(build_root):
 262     mkdir(build_root)
 263 main['BUILDROOT'] = build_root
 264
 265 Export('main')
 266
 267 main.SConsignFile(joinpath(build_root, "sconsign"))
 268
 269 # Default duplicate option is to use hard links, but this messes up
 270 # when you use emacs to edit a file in the target dir, as emacs moves
 271 # file to file~ then copies to file, breaking the link.  Symbolic
 272 # (soft) links work better.
 273 main.SetOption('duplicate', 'soft-copy')
 274
 275 #
 276 # Set up global sticky variables... these are common to an entire build
 277 # tree (not specific to a particular build like ALPHA_SE)
 278 #
 279
 280 global_vars_file = joinpath(build_root, 'variables.global')
 281
 282 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 283
 284 global_vars.AddVariables(
 285     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 286     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 287     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 288     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 289     ('PYTHON_CONFIG', 'Python config binary to use',
 290      [ 'python2.7-config', 'python-config' ]),
 291     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 292     ('BATCH', 'Use batch pool for build and tests', False),
 293     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 294     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 295     ('EXTRAS', 'Add extra directories to the compilation', '')
 296     )
 297
 298 # Update main environment with values from ARGUMENTS & global_vars_file
 299 global_vars.Update(main)
 300 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 301
 302 # Save sticky variable settings back to current variables file
 303 global_vars.Save(global_vars_file, main)
 304
 305 # Parse EXTRAS variable to build list of all directories where we're
 306 # look for sources etc.  This list is exported as extras_dir_list.
 307 base_dir = main.srcdir.abspath
 308 if main['EXTRAS']:
 309     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 310 else:
 311     extras_dir_list = []
 312
 313 Export('base_dir')
 314 Export('extras_dir_list')
 315
 316 # the ext directory should be on the #includes path
 317 main.Append(CPPPATH=[Dir('ext')])
 318
 319 # Add shared top-level headers
 320 main.Prepend(CPPPATH=Dir('include'))
 321
 322 if GetOption('verbose'):
 323     def MakeAction(action, string, *args, **kwargs):
 324         return Action(action, *args, **kwargs)
 325 else:
 326     MakeAction = Action
 327     main['CCCOMSTR']        = Transform("CC")
 328     main['CXXCOMSTR']       = Transform("CXX")
 329     main['ASCOMSTR']        = Transform("AS")
 330     main['ARCOMSTR']        = Transform("AR", 0)
 331     main['LINKCOMSTR']      = Transform("LINK", 0)
 332     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 333     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 334     main['M4COMSTR']        = Transform("M4")
 335     main['SHCCCOMSTR']      = Transform("SHCC")
 336     main['SHCXXCOMSTR']     = Transform("SHCXX")
 337 Export('MakeAction')
 338
 339 # Initialize the Link-Time Optimization (LTO) flags
 340 main['LTO_CCFLAGS'] = []
 341 main['LTO_LDFLAGS'] = []
 342
 343 # According to the readme, tcmalloc works best if the compiler doesn't
 344 # assume that we're using the builtin malloc and friends. These flags
 345 # are compiler-specific, so we need to set them after we detect which
 346 # compiler we're using.
 347 main['TCMALLOC_CCFLAGS'] = []
 348
 349 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 350 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 351
 352 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 353 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 354 if main['GCC'] + main['CLANG'] > 1:
 355     error('Two compilers enabled at once?')
 356
 357 # Set up default C++ compiler flags
 358 if main['GCC'] or main['CLANG']:
 359     # As gcc and clang share many flags, do the common parts here
 360     main.Append(CCFLAGS=['-pipe'])
 361     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 362     # Enable -Wall and -Wextra and then disable the few warnings that
 363     # we consistently violate
 364     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 365                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 366     # We always compile using C++11
 367     main.Append(CXXFLAGS=['-std=c++11'])
 368     if sys.platform.startswith('freebsd'):
 369         main.Append(CCFLAGS=['-I/usr/local/include'])
 370         main.Append(CXXFLAGS=['-I/usr/local/include'])
 371
 372     main.Append(LINKFLAGS='-Wl,--as-needed')
 373     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 374     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 375     if GetOption('gold_linker'):
 376         main.Append(LINKFLAGS='-fuse-ld=gold')
 377     main['PLINKFLAGS'] = main.get('LINKFLAGS')
 378     shared_partial_flags = ['-r', '-nostdlib']
 379     main.Append(PSHLINKFLAGS=shared_partial_flags)
 380     main.Append(PLINKFLAGS=shared_partial_flags)
 381
 382     # Treat warnings as errors but white list some warnings that we
 383     # want to allow (e.g., deprecation warnings).
 384     main.Append(CCFLAGS=['-Werror',
 385                          '-Wno-error=deprecated-declarations',
 386                          '-Wno-error=deprecated',
 387                         ])
 388 else:
 389     error('\n'.join((
 390           "Don't know what compiler options to use for your compiler.",
 391           "compiler: " + main['CXX'],
 392           "version: " + CXX_version.replace('\n', '<nl>') if
 393                 CXX_version else 'COMMAND NOT FOUND!',
 394           "If you're trying to use a compiler other than GCC",
 395           "or clang, there appears to be something wrong with your",
 396           "environment.",
 397           "",
 398           "If you are trying to use a compiler other than those listed",
 399           "above you will need to ease fix SConstruct and ",
 400           "src/SConscript to support that compiler.")))
 401
 402 if main['GCC']:
 403     # Check for a supported version of gcc. >= 4.8 is chosen for its
 404     # level of c++11 support. See
 405     # http://gcc.gnu.org/projects/cxx0x.html for details.
 406     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 407     if compareVersions(gcc_version, "4.8") < 0:
 408         error('gcc version 4.8 or newer required.\n'
 409               'Installed version:', gcc_version)
 410         Exit(1)
 411
 412     main['GCC_VERSION'] = gcc_version
 413
 414     if compareVersions(gcc_version, '4.9') >= 0:
 415         # Incremental linking with LTO is currently broken in gcc versions
 416         # 4.9 and above. A version where everything works completely hasn't
 417         # yet been identified.
 418         #
 419         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 420         main['BROKEN_INCREMENTAL_LTO'] = True
 421     if compareVersions(gcc_version, '6.0') >= 0:
 422         # gcc versions 6.0 and greater accept an -flinker-output flag which
 423         # selects what type of output the linker should generate. This is
 424         # necessary for incremental lto to work, but is also broken in
 425         # current versions of gcc. It may not be necessary in future
 426         # versions. We add it here since it might be, and as a reminder that
 427         # it exists. It's excluded if lto is being forced.
 428         #
 429         # https://gcc.gnu.org/gcc-6/changes.html
 430         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 431         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 432         if not GetOption('force_lto'):
 433             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 434             main.Append(PLINKFLAGS='-flinker-output=rel')
 435
 436     disable_lto = GetOption('no_lto')
 437     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 438             not GetOption('force_lto'):
 439         warning('Warning: Your compiler doesn\'t support incremental linking '
 440                 'and lto at the same time, so lto is being disabled. To force '
 441                 'lto on anyway, use the --force-lto option. That will disable '
 442                 'partial linking.')
 443         disable_lto = True
 444
 445     # Add the appropriate Link-Time Optimization (LTO) flags
 446     # unless LTO is explicitly turned off. Note that these flags
 447     # are only used by the fast target.
 448     if not disable_lto:
 449         # Pass the LTO flag when compiling to produce GIMPLE
 450         # output, we merely create the flags here and only append
 451         # them later
 452         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 453
 454         # Use the same amount of jobs for LTO as we are running
 455         # scons with
 456         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 457
 458     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 459                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 460
 461 elif main['CLANG']:
 462     # Check for a supported version of clang, >= 3.1 is needed to
 463     # support similar features as gcc 4.8. See
 464     # http://clang.llvm.org/cxx_status.html for details
 465     clang_version_re = re.compile(".* version (\d+\.\d+)")
 466     clang_version_match = clang_version_re.search(CXX_version)
 467     if (clang_version_match):
 468         clang_version = clang_version_match.groups()[0]
 469         if compareVersions(clang_version, "3.1") < 0:
 470             error('clang version 3.1 or newer required.\n'
 471                   'Installed version:', clang_version)
 472     else:
 473         error('Unable to determine clang version.')
 474
 475     # clang has a few additional warnings that we disable, extraneous
 476     # parantheses are allowed due to Ruby's printing of the AST,
 477     # finally self assignments are allowed as the generated CPU code
 478     # is relying on this
 479     main.Append(CCFLAGS=['-Wno-parentheses',
 480                          '-Wno-self-assign',
 481                          # Some versions of libstdc++ (4.8?) seem to
 482                          # use struct hash and class hash
 483                          # interchangeably.
 484                          '-Wno-mismatched-tags',
 485                          ])
 486
 487     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 488
 489     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 490     # opposed to libstdc++, as the later is dated.
 491     if sys.platform == "darwin":
 492         main.Append(CXXFLAGS=['-stdlib=libc++'])
 493         main.Append(LIBS=['c++'])
 494
 495     # On FreeBSD we need libthr.
 496     if sys.platform.startswith('freebsd'):
 497         main.Append(LIBS=['thr'])
 498
 499 # Add sanitizers flags
 500 sanitizers=[]
 501 if GetOption('with_ubsan'):
 502     # Only gcc >= 4.9 supports UBSan, so check both the version
 503     # and the command-line option before adding the compiler and
 504     # linker flags.
 505     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 506         sanitizers.append('undefined')
 507 if GetOption('with_asan'):
 508     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 509     # by the build system
 510     sanitizers.append('address')
 511 if sanitizers:
 512     sanitizers = ','.join(sanitizers)
 513     if main['GCC'] or main['CLANG']:
 514         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 515                              '-fno-omit-frame-pointer'],
 516                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 517     else:
 518         warning("Don't know how to enable %s sanitizer(s) for your "
 519                 "compiler." % sanitizers)
 520
 521 # Set up common yacc/bison flags (needed for Ruby)
 522 main['YACCFLAGS'] = '-d'
 523 main['YACCHXXFILESUFFIX'] = '.hh'
 524
 525 # Do this after we save setting back, or else we'll tack on an
 526 # extra 'qdo' every time we run scons.
 527 if main['BATCH']:
 528     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 529     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 530     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 531     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 532     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 533
 534 if sys.platform == 'cygwin':
 535     # cygwin has some header file issues...
 536     main.Append(CCFLAGS=["-Wno-uninitialized"])
 537
 538
 539 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 540
 541 # Check for the protobuf compiler
 542 try:
 543     main['HAVE_PROTOC'] = True
 544     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 545
 546     # First two words should be "libprotoc x.y.z"
 547     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 548         warning('Protocol buffer compiler (protoc) not found.\n'
 549                 'Please install protobuf-compiler for tracing support.')
 550         main['HAVE_PROTOC'] = False
 551     else:
 552         # Based on the availability of the compress stream wrappers,
 553         # require 2.1.0
 554         min_protoc_version = '2.1.0'
 555         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 556             warning('protoc version', min_protoc_version,
 557                     'or newer required.\n'
 558                     'Installed version:', protoc_version[1])
 559             main['HAVE_PROTOC'] = False
 560         else:
 561             # Attempt to determine the appropriate include path and
 562             # library path using pkg-config, that means we also need to
 563             # check for pkg-config. Note that it is possible to use
 564             # protobuf without the involvement of pkg-config. Later on we
 565             # check go a library config check and at that point the test
 566             # will fail if libprotobuf cannot be found.
 567             if have_pkg_config:
 568                 try:
 569                     # Attempt to establish what linking flags to add for
 570                     # protobuf
 571                     # using pkg-config
 572                     main.ParseConfig(
 573                             'pkg-config --cflags --libs-only-L protobuf')
 574                 except:
 575                     warning('pkg-config could not get protobuf flags.')
 576 except Exception as e:
 577     warning('While checking protoc version:', str(e))
 578     main['HAVE_PROTOC'] = False
 579
 580 # Check for 'timeout' from GNU coreutils. If present, regressions will
 581 # be run with a time limit. We require version 8.13 since we rely on
 582 # support for the '--foreground' option.
 583 if sys.platform.startswith('freebsd'):
 584     timeout_lines = readCommand(['gtimeout', '--version'],
 585                                 exception='').splitlines()
 586 else:
 587     timeout_lines = readCommand(['timeout', '--version'],
 588                                 exception='').splitlines()
 589 # Get the first line and tokenize it
 590 timeout_version = timeout_lines[0].split() if timeout_lines else []
 591 main['TIMEOUT'] =  timeout_version and \
 592     compareVersions(timeout_version[-1], '8.13') >= 0
 593
 594 # Add a custom Check function to test for structure members.
 595 def CheckMember(context, include, decl, member, include_quotes="<>"):
 596     context.Message("Checking for member %s in %s..." %
 597                     (member, decl))
 598     text = """
 599 #include %(header)s
 600 int main(){
 601   %(decl)s test;
 602   (void)test.%(member)s;
 603   return 0;
 604 };
 605 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 606         "decl" : decl,
 607         "member" : member,
 608         }
 609
 610     ret = context.TryCompile(text, extension=".cc")
 611     context.Result(ret)
 612     return ret
 613
 614 # Platform-specific configuration.  Note again that we assume that all
 615 # builds under a given build root run on the same host platform.
 616 conf = Configure(main,
 617                  conf_dir = joinpath(build_root, '.scons_config'),
 618                  log_file = joinpath(build_root, 'scons_config.log'),
 619                  custom_tests = {
 620         'CheckMember' : CheckMember,
 621         })
 622
 623 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 624 try:
 625     import platform
 626     uname = platform.uname()
 627     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 628         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 629             main.Append(CCFLAGS=['-arch', 'x86_64'])
 630             main.Append(CFLAGS=['-arch', 'x86_64'])
 631             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 632             main.Append(ASFLAGS=['-arch', 'x86_64'])
 633 except:
 634     pass
 635
 636 # Recent versions of scons substitute a "Null" object for Configure()
 637 # when configuration isn't necessary, e.g., if the "--help" option is
 638 # present.  Unfortuantely this Null object always returns false,
 639 # breaking all our configuration checks.  We replace it with our own
 640 # more optimistic null object that returns True instead.
 641 if not conf:
 642     def NullCheck(*args, **kwargs):
 643         return True
 644
 645     class NullConf:
 646         def __init__(self, env):
 647             self.env = env
 648         def Finish(self):
 649             return self.env
 650         def __getattr__(self, mname):
 651             return NullCheck
 652
 653     conf = NullConf(main)
 654
 655 # Cache build files in the supplied directory.
 656 if main['M5_BUILD_CACHE']:
 657     print('Using build cache located at', main['M5_BUILD_CACHE'])
 658     CacheDir(main['M5_BUILD_CACHE'])
 659
 660 main['USE_PYTHON'] = not GetOption('without_python')
 661 if main['USE_PYTHON']:
 662     # Find Python include and library directories for embedding the
 663     # interpreter. We rely on python-config to resolve the appropriate
 664     # includes and linker flags. ParseConfig does not seem to understand
 665     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 666     # we add them explicitly below. If you want to link in an alternate
 667     # version of python, see above for instructions on how to invoke
 668     # scons with the appropriate PATH set.
 669
 670     python_config = find_first_prog(main['PYTHON_CONFIG'])
 671     if python_config is None:
 672         error("Can't find a suitable python-config, tried %s" % \
 673               main['PYTHON_CONFIG'])
 674
 675     print("Info: Using Python config: %s" % (python_config, ))
 676     py_includes = readCommand([python_config, '--includes'],
 677                               exception='').split()
 678     py_includes = filter(lambda s: match(r'.*\/include\/.*',s), py_includes)
 679     # Strip the -I from the include folders before adding them to the
 680     # CPPPATH
 681     py_includes = map(lambda s: s[2:] if s.startswith('-I') else s, py_includes)
 682     main.Append(CPPPATH=py_includes)
 683
 684     # Read the linker flags and split them into libraries and other link
 685     # flags. The libraries are added later through the call the CheckLib.
 686     py_ld_flags = readCommand([python_config, '--ldflags'],
 687         exception='').split()
 688     py_libs = []
 689     for lib in py_ld_flags:
 690          if not lib.startswith('-l'):
 691              main.Append(LINKFLAGS=[lib])
 692          else:
 693              lib = lib[2:]
 694              if lib not in py_libs:
 695                  py_libs.append(lib)
 696
 697     # verify that this stuff works
 698     if not conf.CheckHeader('Python.h', '<>'):
 699         error("Check failed for Python.h header in",
 700                 ' '.join(py_includes), "\n"
 701               "Two possible reasons:\n"
 702               "1. Python headers are not installed (You can install the "
 703               "package python-dev on Ubuntu and RedHat)\n"
 704               "2. SCons is using a wrong C compiler. This can happen if "
 705               "CC has the wrong value.\n"
 706               "CC = %s" % main['CC'])
 707
 708     for lib in py_libs:
 709         if not conf.CheckLib(lib):
 710             error("Can't find library %s required by python." % lib)
 711
 712 # On Solaris you need to use libsocket for socket ops
 713 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 714    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 715                                   'C++', 'accept(0,0,0);'):
 716        error("Can't find library with socket calls (e.g. accept()).")
 717
 718 # Check for zlib.  If the check passes, libz will be automatically
 719 # added to the LIBS environment variable.
 720 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 721     error('Did not find needed zlib compression library '
 722           'and/or zlib.h header file.\n'
 723           'Please install zlib and try again.')
 724
 725 # If we have the protobuf compiler, also make sure we have the
 726 # development libraries. If the check passes, libprotobuf will be
 727 # automatically added to the LIBS environment variable. After
 728 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 729 # got both protoc and libprotobuf available.
 730 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 731     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 732                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 733
 734 # Valgrind gets much less confused if you tell it when you're using
 735 # alternative stacks.
 736 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 737
 738 # If we have the compiler but not the library, print another warning.
 739 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 740     warning('Did not find protocol buffer library and/or headers.\n'
 741             'Please install libprotobuf-dev for tracing support.')
 742
 743 # Check for librt.
 744 have_posix_clock = \
 745     conf.CheckLibWithHeader(None, 'time.h', 'C',
 746                             'clock_nanosleep(0,0,NULL,NULL);') or \
 747     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 748                             'clock_nanosleep(0,0,NULL,NULL);')
 749
 750 have_posix_timers = \
 751     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 752                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 753
 754 if not GetOption('without_tcmalloc'):
 755     if conf.CheckLib('tcmalloc'):
 756         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 757     elif conf.CheckLib('tcmalloc_minimal'):
 758         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 759     else:
 760         warning("You can get a 12% performance improvement by "
 761                 "installing tcmalloc (libgoogle-perftools-dev package "
 762                 "on Ubuntu or RedHat).")
 763
 764
 765 # Detect back trace implementations. The last implementation in the
 766 # list will be used by default.
 767 backtrace_impls = [ "none" ]
 768
 769 backtrace_checker = 'char temp;' + \
 770     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 771 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 772     backtrace_impls.append("glibc")
 773 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 774                              backtrace_checker):
 775     # NetBSD and FreeBSD need libexecinfo.
 776     backtrace_impls.append("glibc")
 777     main.Append(LIBS=['execinfo'])
 778
 779 if backtrace_impls[-1] == "none":
 780     default_backtrace_impl = "none"
 781     warning("No suitable back trace implementation found.")
 782
 783 if not have_posix_clock:
 784     warning("Can't find library for POSIX clocks.")
 785
 786 # Check for <fenv.h> (C99 FP environment control)
 787 have_fenv = conf.CheckHeader('fenv.h', '<>')
 788 if not have_fenv:
 789     warning("Header file <fenv.h> not found.\n"
 790             "This host has no IEEE FP rounding mode control.")
 791
 792 # Check for <png.h> (libpng library needed if wanting to dump
 793 # frame buffer image in png format)
 794 have_png = conf.CheckHeader('png.h', '<>')
 795 if not have_png:
 796     warning("Header file <png.h> not found.\n"
 797             "This host has no libpng library.\n"
 798             "Disabling support for PNG framebuffers.")
 799
 800 # Check if we should enable KVM-based hardware virtualization. The API
 801 # we rely on exists since version 2.6.36 of the kernel, but somehow
 802 # the KVM_API_VERSION does not reflect the change. We test for one of
 803 # the types as a fall back.
 804 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 805 if not have_kvm:
 806     print("Info: Compatible header file <linux/kvm.h> not found, "
 807           "disabling KVM support.")
 808
 809 # Check if the TUN/TAP driver is available.
 810 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 811 if not have_tuntap:
 812     print("Info: Compatible header file <linux/if_tun.h> not found.")
 813
 814 # x86 needs support for xsave. We test for the structure here since we
 815 # won't be able to run new tests by the time we know which ISA we're
 816 # targeting.
 817 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 818                                     '#include <linux/kvm.h>') != 0
 819
 820 # Check if the requested target ISA is compatible with the host
 821 def is_isa_kvm_compatible(isa):
 822     try:
 823         import platform
 824         host_isa = platform.machine()
 825     except:
 826         warning("Failed to determine host ISA.")
 827         return False
 828
 829     if not have_posix_timers:
 830         warning("Can not enable KVM, host seems to lack support "
 831                 "for POSIX timers")
 832         return False
 833
 834     if isa == "arm":
 835         return host_isa in ( "armv7l", "aarch64" )
 836     elif isa == "x86":
 837         if host_isa != "x86_64":
 838             return False
 839
 840         if not have_kvm_xsave:
 841             warning("KVM on x86 requires xsave support in kernel headers.")
 842             return False
 843
 844         return True
 845     else:
 846         return False
 847
 848
 849 # Check if the exclude_host attribute is available. We want this to
 850 # get accurate instruction counts in KVM.
 851 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 852     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 853
 854 def check_hdf5():
 855     return \
 856         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 857                                 'H5Fcreate("", 0, 0, 0);') and \
 858         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 859                                 'H5::H5File("", 0);')
 860
 861 def check_hdf5_pkg(name):
 862     print("Checking for %s using pkg-config..." % name, end="")
 863     if not have_pkg_config:
 864         print(" pkg-config not found")
 865         return False
 866
 867     try:
 868         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 869         print(" yes")
 870         return True
 871     except:
 872         print(" no")
 873         return False
 874
 875 # Check if there is a pkg-config configuration for hdf5. If we find
 876 # it, setup the environment to enable linking and header inclusion. We
 877 # don't actually try to include any headers or link with hdf5 at this
 878 # stage.
 879 if not check_hdf5_pkg('hdf5-serial'):
 880     check_hdf5_pkg('hdf5')
 881
 882 # Check if the HDF5 libraries can be found. This check respects the
 883 # include path and library path provided by pkg-config. We perform
 884 # this check even if there isn't a pkg-config configuration for hdf5
 885 # since some installations don't use pkg-config.
 886 have_hdf5 = check_hdf5()
 887 if not have_hdf5:
 888     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 889     print("         HDF5 support.")
 890
 891 ######################################################################
 892 #
 893 # Finish the configuration
 894 #
 895 main = conf.Finish()
 896
 897 ######################################################################
 898 #
 899 # Collect all non-global variables
 900 #
 901
 902 # Define the universe of supported ISAs
 903 all_isa_list = [ ]
 904 all_gpu_isa_list = [ ]
 905 Export('all_isa_list')
 906 Export('all_gpu_isa_list')
 907
 908 class CpuModel(object):
 909     '''The CpuModel class encapsulates everything the ISA parser needs to
 910     know about a particular CPU model.'''
 911
 912     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 913     dict = {}
 914
 915     # Constructor.  Automatically adds models to CpuModel.dict.
 916     def __init__(self, name, default=False):
 917         self.name = name           # name of model
 918
 919         # This cpu is enabled by default
 920         self.default = default
 921
 922         # Add self to dict
 923         if name in CpuModel.dict:
 924             raise AttributeError("CpuModel '%s' already registered" % name)
 925         CpuModel.dict[name] = self
 926
 927 Export('CpuModel')
 928
 929 # Sticky variables get saved in the variables file so they persist from
 930 # one invocation to the next (unless overridden, in which case the new
 931 # value becomes sticky).
 932 sticky_vars = Variables(args=ARGUMENTS)
 933 Export('sticky_vars')
 934
 935 # Sticky variables that should be exported
 936 export_vars = []
 937 Export('export_vars')
 938
 939 # For Ruby
 940 all_protocols = []
 941 Export('all_protocols')
 942 protocol_dirs = []
 943 Export('protocol_dirs')
 944 slicc_includes = []
 945 Export('slicc_includes')
 946
 947 # Walk the tree and execute all SConsopts scripts that wil add to the
 948 # above variables
 949 if GetOption('verbose'):
 950     print("Reading SConsopts")
 951 for bdir in [ base_dir ] + extras_dir_list:
 952     if not isdir(bdir):
 953         error("Directory '%s' does not exist." % bdir)
 954     for root, dirs, files in os.walk(bdir):
 955         if 'SConsopts' in files:
 956             if GetOption('verbose'):
 957                 print("Reading", joinpath(root, 'SConsopts'))
 958             SConscript(joinpath(root, 'SConsopts'))
 959
 960 all_isa_list.sort()
 961 all_gpu_isa_list.sort()
 962
 963 sticky_vars.AddVariables(
 964     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 965     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 966     ListVariable('CPU_MODELS', 'CPU models',
 967                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
 968                  sorted(CpuModel.dict.keys())),
 969     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 970                  False),
 971     BoolVariable('USE_SSE2',
 972                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 973                  False),
 974     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 975     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 976     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 977     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
 978                  False),
 979     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 980                  have_kvm),
 981     BoolVariable('USE_TUNTAP',
 982                  'Enable using a tap device to bridge to the host network',
 983                  have_tuntap),
 984     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
 985     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
 986                   all_protocols),
 987     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
 988                  backtrace_impls[-1], backtrace_impls),
 989     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
 990                  64),
 991     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
 992     )
 993
 994 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 995 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
 996                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
 997                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
 998                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
 999                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1000
1001 ###################################################
1002 #
1003 # Define a SCons builder for configuration flag headers.
1004 #
1005 ###################################################
1006
1007 # This function generates a config header file that #defines the
1008 # variable symbol to the current variable setting (0 or 1).  The source
1009 # operands are the name of the variable and a Value node containing the
1010 # value of the variable.
1011 def build_config_file(target, source, env):
1012     (variable, value) = [s.get_contents() for s in source]
1013     f = file(str(target[0]), 'w')
1014     print('#define', variable, value, file=f)
1015     f.close()
1016     return None
1017
1018 # Combine the two functions into a scons Action object.
1019 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1020
1021 # The emitter munges the source & target node lists to reflect what
1022 # we're really doing.
1023 def config_emitter(target, source, env):
1024     # extract variable name from Builder arg
1025     variable = str(target[0])
1026     # True target is config header file
1027     target = joinpath('config', variable.lower() + '.hh')
1028     val = env[variable]
1029     if isinstance(val, bool):
1030         # Force value to 0/1
1031         val = int(val)
1032     elif isinstance(val, str):
1033         val = '"' + val + '"'
1034
1035     # Sources are variable name & value (packaged in SCons Value nodes)
1036     return ([target], [Value(variable), Value(val)])
1037
1038 config_builder = Builder(emitter = config_emitter, action = config_action)
1039
1040 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1041
1042 ###################################################
1043 #
1044 # Builders for static and shared partially linked object files.
1045 #
1046 ###################################################
1047
1048 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1049                                  src_suffix='$OBJSUFFIX',
1050                                  src_builder=['StaticObject', 'Object'],
1051                                  LINKFLAGS='$PLINKFLAGS',
1052                                  LIBS='')
1053
1054 def partial_shared_emitter(target, source, env):
1055     for tgt in target:
1056         tgt.attributes.shared = 1
1057     return (target, source)
1058 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1059                                  emitter=partial_shared_emitter,
1060                                  src_suffix='$SHOBJSUFFIX',
1061                                  src_builder='SharedObject',
1062                                  SHLINKFLAGS='$PSHLINKFLAGS',
1063                                  LIBS='')
1064
1065 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1066                          'PartialStatic' : partial_static_builder })
1067
1068 def add_local_rpath(env, *targets):
1069     '''Set up an RPATH for a library which lives in the build directory.
1070
1071     The construction environment variable BIN_RPATH_PREFIX should be set to
1072     the relative path of the build directory starting from the location of the
1073     binary.'''
1074     for target in targets:
1075         target = env.Entry(target)
1076         if not isinstance(target, SCons.Node.FS.Dir):
1077             target = target.dir
1078         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1079         components = [
1080             '\\$$ORIGIN',
1081             '${BIN_RPATH_PREFIX}',
1082             relpath
1083         ]
1084         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1085
1086 if sys.platform != "darwin":
1087     main.Append(LINKFLAGS=Split('-z origin'))
1088
1089 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1090
1091 # builds in ext are shared across all configs in the build root.
1092 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1093 ext_build_dirs = []
1094 for root, dirs, files in os.walk(ext_dir):
1095     if 'SConscript' in files:
1096         build_dir = os.path.relpath(root, ext_dir)
1097         ext_build_dirs.append(build_dir)
1098         main.SConscript(joinpath(root, 'SConscript'),
1099                         variant_dir=joinpath(build_root, build_dir))
1100
1101 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1102 Export('gdb_xml_dir')
1103
1104 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1105
1106 ###################################################
1107 #
1108 # This builder and wrapper method are used to set up a directory with
1109 # switching headers. Those are headers which are in a generic location and
1110 # that include more specific headers from a directory chosen at build time
1111 # based on the current build settings.
1112 #
1113 ###################################################
1114
1115 def build_switching_header(target, source, env):
1116     path = str(target[0])
1117     subdir = str(source[0])
1118     dp, fp = os.path.split(path)
1119     dp = os.path.relpath(os.path.realpath(dp),
1120                          os.path.realpath(env['BUILDDIR']))
1121     with open(path, 'w') as hdr:
1122         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1123
1124 switching_header_action = MakeAction(build_switching_header,
1125                                      Transform('GENERATE'))
1126
1127 switching_header_builder = Builder(action=switching_header_action,
1128                                    source_factory=Value,
1129                                    single_source=True)
1130
1131 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1132
1133 def switching_headers(self, headers, source):
1134     for header in headers:
1135         self.SwitchingHeader(header, source)
1136
1137 main.AddMethod(switching_headers, 'SwitchingHeaders')
1138
1139 ###################################################
1140 #
1141 # Define build environments for selected configurations.
1142 #
1143 ###################################################
1144
1145 for variant_path in variant_paths:
1146     if not GetOption('silent'):
1147         print("Building in", variant_path)
1148
1149     # Make a copy of the build-root environment to use for this config.
1150     env = main.Clone()
1151     env['BUILDDIR'] = variant_path
1152
1153     # variant_dir is the tail component of build path, and is used to
1154     # determine the build parameters (e.g., 'ALPHA_SE')
1155     (build_root, variant_dir) = splitpath(variant_path)
1156
1157     # Set env variables according to the build directory config.
1158     sticky_vars.files = []
1159     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1160     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1161     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1162     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1163     if isfile(current_vars_file):
1164         sticky_vars.files.append(current_vars_file)
1165         if not GetOption('silent'):
1166             print("Using saved variables file %s" % current_vars_file)
1167     elif variant_dir in ext_build_dirs:
1168         # Things in ext are built without a variant directory.
1169         continue
1170     else:
1171         # Build dir-specific variables file doesn't exist.
1172
1173         # Make sure the directory is there so we can create it later
1174         opt_dir = dirname(current_vars_file)
1175         if not isdir(opt_dir):
1176             mkdir(opt_dir)
1177
1178         # Get default build variables from source tree.  Variables are
1179         # normally determined by name of $VARIANT_DIR, but can be
1180         # overridden by '--default=' arg on command line.
1181         default = GetOption('default')
1182         opts_dir = joinpath(main.root.abspath, 'build_opts')
1183         if default:
1184             default_vars_files = [joinpath(build_root, 'variables', default),
1185                                   joinpath(opts_dir, default)]
1186         else:
1187             default_vars_files = [joinpath(opts_dir, variant_dir)]
1188         existing_files = filter(isfile, default_vars_files)
1189         if existing_files:
1190             default_vars_file = existing_files[0]
1191             sticky_vars.files.append(default_vars_file)
1192             print("Variables file %s not found,\n  using defaults in %s"
1193                   % (current_vars_file, default_vars_file))
1194         else:
1195             error("Cannot find variables file %s or default file(s) %s"
1196                   % (current_vars_file, ' or '.join(default_vars_files)))
1197             Exit(1)
1198
1199     # Apply current variable settings to env
1200     sticky_vars.Update(env)
1201
1202     help_texts["local_vars"] += \
1203         "Build variables for %s:\n" % variant_dir \
1204                  + sticky_vars.GenerateHelpText(env)
1205
1206     # Process variable settings.
1207
1208     if not have_fenv and env['USE_FENV']:
1209         warning("<fenv.h> not available; forcing USE_FENV to False in",
1210                 variant_dir + ".")
1211         env['USE_FENV'] = False
1212
1213     if not env['USE_FENV']:
1214         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1215                 "FP results may deviate slightly from other platforms.")
1216
1217     if not have_png and env['USE_PNG']:
1218         warning("<png.h> not available; forcing USE_PNG to False in",
1219                 variant_dir + ".")
1220         env['USE_PNG'] = False
1221
1222     if env['USE_PNG']:
1223         env.Append(LIBS=['png'])
1224
1225     if env['EFENCE']:
1226         env.Append(LIBS=['efence'])
1227
1228     if env['USE_KVM']:
1229         if not have_kvm:
1230             warning("Can not enable KVM, host seems to lack KVM support")
1231             env['USE_KVM'] = False
1232         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1233             print("Info: KVM support disabled due to unsupported host and "
1234                   "target ISA combination")
1235             env['USE_KVM'] = False
1236
1237     if env['USE_TUNTAP']:
1238         if not have_tuntap:
1239             warning("Can't connect EtherTap with a tap device.")
1240             env['USE_TUNTAP'] = False
1241
1242     if env['BUILD_GPU']:
1243         env.Append(CPPDEFINES=['BUILD_GPU'])
1244
1245     # Warn about missing optional functionality
1246     if env['USE_KVM']:
1247         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1248             warning("perf_event headers lack support for the exclude_host "
1249                     "attribute. KVM instruction counts will be inaccurate.")
1250
1251     # Save sticky variable settings back to current variables file
1252     sticky_vars.Save(current_vars_file, env)
1253
1254     if env['USE_SSE2']:
1255         env.Append(CCFLAGS=['-msse2'])
1256
1257     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1258     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1259
1260     # The src/SConscript file sets up the build rules in 'env' according
1261     # to the configured variables.  It returns a list of environments,
1262     # one for each variant build (debug, opt, etc.)
1263     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1264
1265 # base help text
1266 Help('''
1267 Usage: scons [scons options] [build variables] [target(s)]
1268
1269 Extra scons options:
1270 %(options)s
1271
1272 Global build variables:
1273 %(global_vars)s
1274
1275 %(local_vars)s
1276 ''' % help_texts)