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/X86/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/X86/gem5.debug
  62 #   % cd <path-to-src>/gem5/build/X86; 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/X86/gem5.debug
  69 #   % cd /local/foo/build/X86; 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 atexit
  82 import itertools
  83 import os
  84 import re
  85 import shutil
  86 import subprocess
  87 import sys
  88
  89 from os import mkdir, environ
  90 from os.path import abspath, basename, dirname, expanduser, normpath
  91 from os.path import exists,  isdir, isfile
  92 from os.path import join as joinpath, split as splitpath
  93 from re import match
  94
  95 # SCons includes
  96 import SCons
  97 import SCons.Node
  98 import SCons.Node.FS
  99
 100 from m5.util import compareVersions, readCommand, readCommandWithReturn
 101
 102 AddOption('--colors', dest='use_colors', action='store_true',
 103           help="Add color to abbreviated scons output")
 104 AddOption('--no-colors', dest='use_colors', action='store_false',
 105           help="Don't add color to abbreviated scons output")
 106 AddOption('--with-cxx-config', action='store_true',
 107           help="Build with support for C++-based configuration")
 108 AddOption('--default',
 109           help='Override which build_opts file to use for defaults')
 110 AddOption('--ignore-style', action='store_true',
 111           help='Disable style checking hooks')
 112 AddOption('--gold-linker', action='store_true', help='Use the gold linker')
 113 AddOption('--no-lto', action='store_true',
 114           help='Disable Link-Time Optimization for fast')
 115 AddOption('--force-lto', action='store_true',
 116           help='Use Link-Time Optimization instead of partial linking' +
 117                ' when the compiler doesn\'t support using them together.')
 118 AddOption('--verbose', action='store_true',
 119           help='Print full tool command lines')
 120 AddOption('--without-python', action='store_true',
 121           help='Build without Python configuration support')
 122 AddOption('--without-tcmalloc', action='store_true',
 123           help='Disable linking against tcmalloc')
 124 AddOption('--with-ubsan', action='store_true',
 125           help='Build with Undefined Behavior Sanitizer if available')
 126 AddOption('--with-asan', action='store_true',
 127           help='Build with Address Sanitizer if available')
 128 AddOption('--with-systemc-tests', action='store_true',
 129           help='Build systemc tests')
 130
 131 from gem5_scons import Transform, error, warning, summarize_warnings
 132
 133 if GetOption('no_lto') and GetOption('force_lto'):
 134     error('--no-lto and --force-lto are mutually exclusive')
 135
 136 ########################################################################
 137 #
 138 # Set up the main build environment.
 139 #
 140 ########################################################################
 141
 142 main = Environment()
 143
 144 from gem5_scons.util import get_termcap
 145 termcap = get_termcap()
 146
 147 main_dict_keys = main.Dictionary().keys()
 148
 149 # Check that we have a C/C++ compiler
 150 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 151     error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 152
 153 ###################################################
 154 #
 155 # Figure out which configurations to set up based on the path(s) of
 156 # the target(s).
 157 #
 158 ###################################################
 159
 160 # Find default configuration & binary.
 161 Default(environ.get('M5_DEFAULT_BINARY', 'build/ARM/gem5.debug'))
 162
 163 # helper function: find last occurrence of element in list
 164 def rfind(l, elt, offs = -1):
 165     for i in range(len(l)+offs, 0, -1):
 166         if l[i] == elt:
 167             return i
 168     raise ValueError("element not found")
 169
 170 # Take a list of paths (or SCons Nodes) and return a list with all
 171 # paths made absolute and ~-expanded.  Paths will be interpreted
 172 # relative to the launch directory unless a different root is provided
 173 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 174     return [abspath(joinpath(root, expanduser(str(p))))
 175             for p in path_list]
 176
 177 # Each target must have 'build' in the interior of the path; the
 178 # directory below this will determine the build parameters.  For
 179 # example, for target 'foo/bar/build/X86/arch/x86/blah.do' we
 180 # recognize that X86 specifies the configuration because it
 181 # follow 'build' in the build path.
 182
 183 # The funky assignment to "[:]" is needed to replace the list contents
 184 # in place rather than reassign the symbol to a new list, which
 185 # doesn't work (obviously!).
 186 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 187
 188 # Generate a list of the unique build roots and configs that the
 189 # collected targets reference.
 190 variant_paths = []
 191 build_root = None
 192 for t in BUILD_TARGETS:
 193     path_dirs = t.split('/')
 194     try:
 195         build_top = rfind(path_dirs, 'build', -2)
 196     except:
 197         error("No non-leaf 'build' dir found on target path.", t)
 198     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 199     if not build_root:
 200         build_root = this_build_root
 201     else:
 202         if this_build_root != build_root:
 203             error("build targets not under same build root\n"
 204                   "  %s\n  %s" % (build_root, this_build_root))
 205     variant_path = joinpath('/',*path_dirs[:build_top+2])
 206     if variant_path not in variant_paths:
 207         variant_paths.append(variant_path)
 208
 209 # Make sure build_root exists (might not if this is the first build there)
 210 if not isdir(build_root):
 211     mkdir(build_root)
 212 main['BUILDROOT'] = build_root
 213
 214 Export('main')
 215
 216 main.SConsignFile(joinpath(build_root, "sconsign"))
 217
 218 # Default duplicate option is to use hard links, but this messes up
 219 # when you use emacs to edit a file in the target dir, as emacs moves
 220 # file to file~ then copies to file, breaking the link.  Symbolic
 221 # (soft) links work better.
 222 main.SetOption('duplicate', 'soft-copy')
 223
 224 #
 225 # Set up global sticky variables... these are common to an entire build
 226 # tree (not specific to a particular build like X86)
 227 #
 228
 229 global_vars_file = joinpath(build_root, 'variables.global')
 230
 231 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 232
 233 global_vars.AddVariables(
 234     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 235     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 236     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 237     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 238     ('MARSHAL_CCFLAGS_EXTRA', 'Extra C and C++ marshal compiler flags', ''),
 239     ('MARSHAL_LDFLAGS_EXTRA', 'Extra marshal linker flags', ''),
 240     ('PYTHON_CONFIG', 'Python config binary to use',
 241      [ 'python3-config', 'python-config', 'python2.7-config', 'python2-config']
 242     ),
 243     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 244     ('BATCH', 'Use batch pool for build and tests', False),
 245     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 246     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 247     ('EXTRAS', 'Add extra directories to the compilation', '')
 248     )
 249
 250 # Update main environment with values from ARGUMENTS & global_vars_file
 251 global_vars.Update(main)
 252 Help('''
 253 Global build variables:
 254 {help}
 255 '''.format(help=global_vars.GenerateHelpText(main)), append=True)
 256
 257 # Save sticky variable settings back to current variables file
 258 global_vars.Save(global_vars_file, main)
 259
 260 # Parse EXTRAS variable to build list of all directories where we're
 261 # look for sources etc.  This list is exported as extras_dir_list.
 262 base_dir = main.srcdir.abspath
 263 if main['EXTRAS']:
 264     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 265 else:
 266     extras_dir_list = []
 267
 268 Export('base_dir')
 269 Export('extras_dir_list')
 270
 271 # the ext directory should be on the #includes path
 272 main.Append(CPPPATH=[Dir('ext')])
 273
 274 # Add shared top-level headers
 275 main.Prepend(CPPPATH=Dir('include'))
 276
 277 if GetOption('verbose'):
 278     def MakeAction(action, string, *args, **kwargs):
 279         return Action(action, *args, **kwargs)
 280 else:
 281     MakeAction = Action
 282     main['CCCOMSTR']        = Transform("CC")
 283     main['CXXCOMSTR']       = Transform("CXX")
 284     main['ASCOMSTR']        = Transform("AS")
 285     main['ARCOMSTR']        = Transform("AR", 0)
 286     main['LINKCOMSTR']      = Transform("LINK", 0)
 287     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 288     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 289     main['M4COMSTR']        = Transform("M4")
 290     main['SHCCCOMSTR']      = Transform("SHCC")
 291     main['SHCXXCOMSTR']     = Transform("SHCXX")
 292 Export('MakeAction')
 293
 294 # Initialize the Link-Time Optimization (LTO) flags
 295 main['LTO_CCFLAGS'] = []
 296 main['LTO_LDFLAGS'] = []
 297
 298 # According to the readme, tcmalloc works best if the compiler doesn't
 299 # assume that we're using the builtin malloc and friends. These flags
 300 # are compiler-specific, so we need to set them after we detect which
 301 # compiler we're using.
 302 main['TCMALLOC_CCFLAGS'] = []
 303
 304 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 305 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 306
 307 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 308 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 309 if main['GCC'] + main['CLANG'] > 1:
 310     error('Two compilers enabled at once?')
 311
 312 # Set up default C++ compiler flags
 313 if main['GCC'] or main['CLANG']:
 314     # As gcc and clang share many flags, do the common parts here
 315     main.Append(CCFLAGS=['-pipe'])
 316     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 317     # Enable -Wall and -Wextra and then disable the few warnings that
 318     # we consistently violate
 319     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 320                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 321     # We always compile using C++14
 322     main.Append(CXXFLAGS=['-std=c++14'])
 323     if sys.platform.startswith('freebsd'):
 324         main.Append(CCFLAGS=['-I/usr/local/include'])
 325         main.Append(CXXFLAGS=['-I/usr/local/include'])
 326
 327     # On Mac OS X/Darwin the default linker doesn't support the
 328     # option --as-needed
 329     if sys.platform != "darwin":
 330         main.Append(LINKFLAGS='-Wl,--as-needed')
 331     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 332     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 333     if GetOption('gold_linker'):
 334         main.Append(LINKFLAGS='-fuse-ld=gold')
 335     main['PLINKFLAGS'] = main.get('LINKFLAGS')
 336     shared_partial_flags = ['-r', '-nostdlib']
 337     main.Append(PSHLINKFLAGS=shared_partial_flags)
 338     main.Append(PLINKFLAGS=shared_partial_flags)
 339
 340 else:
 341     error('\n'.join((
 342           "Don't know what compiler options to use for your compiler.",
 343           "compiler: " + main['CXX'],
 344           "version: " + CXX_version.replace('\n', '<nl>') if
 345                 CXX_version else 'COMMAND NOT FOUND!',
 346           "If you're trying to use a compiler other than GCC",
 347           "or clang, there appears to be something wrong with your",
 348           "environment.",
 349           "",
 350           "If you are trying to use a compiler other than those listed",
 351           "above you will need to ease fix SConstruct and ",
 352           "src/SConscript to support that compiler.")))
 353
 354 if main['GCC']:
 355     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 356     if compareVersions(gcc_version, "5") < 0:
 357         error('gcc version 5 or newer required.\n'
 358               'Installed version:', gcc_version)
 359         Exit(1)
 360
 361     main['GCC_VERSION'] = gcc_version
 362
 363     # Incremental linking with LTO is currently broken in gcc versions
 364     # 4.9 and above. A version where everything works completely hasn't
 365     # yet been identified.
 366     #
 367     # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 368     main['BROKEN_INCREMENTAL_LTO'] = True
 369
 370     if compareVersions(gcc_version, '6.0') >= 0:
 371         # gcc versions 6.0 and greater accept an -flinker-output flag which
 372         # selects what type of output the linker should generate. This is
 373         # necessary for incremental lto to work, but is also broken in
 374         # current versions of gcc. It may not be necessary in future
 375         # versions. We add it here since it might be, and as a reminder that
 376         # it exists. It's excluded if lto is being forced.
 377         #
 378         # https://gcc.gnu.org/gcc-6/changes.html
 379         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 380         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 381         if not GetOption('force_lto'):
 382             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 383             main.Append(PLINKFLAGS='-flinker-output=rel')
 384
 385     disable_lto = GetOption('no_lto')
 386     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 387             not GetOption('force_lto'):
 388         warning('Your compiler doesn\'t support incremental linking and lto '
 389                 'at the same time, so lto is being disabled. To force lto on '
 390                 'anyway, use the --force-lto option. That will disable '
 391                 'partial linking.')
 392         disable_lto = True
 393
 394     # Add the appropriate Link-Time Optimization (LTO) flags
 395     # unless LTO is explicitly turned off. Note that these flags
 396     # are only used by the fast target.
 397     if not disable_lto:
 398         # Pass the LTO flag when compiling to produce GIMPLE
 399         # output, we merely create the flags here and only append
 400         # them later
 401         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 402
 403         # Use the same amount of jobs for LTO as we are running
 404         # scons with
 405         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 406
 407     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 408                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 409
 410 elif main['CLANG']:
 411     clang_version_re = re.compile(".* version (\d+\.\d+)")
 412     clang_version_match = clang_version_re.search(CXX_version)
 413     if (clang_version_match):
 414         clang_version = clang_version_match.groups()[0]
 415         if compareVersions(clang_version, "3.9") < 0:
 416             error('clang version 3.9 or newer required.\n'
 417                   'Installed version:', clang_version)
 418     else:
 419         error('Unable to determine clang version.')
 420
 421     # clang has a few additional warnings that we disable, extraneous
 422     # parantheses are allowed due to Ruby's printing of the AST,
 423     # finally self assignments are allowed as the generated CPU code
 424     # is relying on this
 425     main.Append(CCFLAGS=['-Wno-parentheses',
 426                          '-Wno-self-assign',
 427                          # Some versions of libstdc++ (4.8?) seem to
 428                          # use struct hash and class hash
 429                          # interchangeably.
 430                          '-Wno-mismatched-tags',
 431                          ])
 432     if sys.platform != "darwin" and \
 433        compareVersions(clang_version, "10.0") >= 0:
 434         main.Append(CCFLAGS=['-Wno-c99-designator'])
 435
 436     if compareVersions(clang_version, "8.0") >= 0:
 437         main.Append(CCFLAGS=['-Wno-defaulted-function-deleted'])
 438
 439     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 440
 441     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 442     # opposed to libstdc++, as the later is dated.
 443     if sys.platform == "darwin":
 444         main.Append(CXXFLAGS=['-stdlib=libc++'])
 445         main.Append(LIBS=['c++'])
 446
 447     # On FreeBSD we need libthr.
 448     if sys.platform.startswith('freebsd'):
 449         main.Append(LIBS=['thr'])
 450
 451 # Add sanitizers flags
 452 sanitizers=[]
 453 if GetOption('with_ubsan'):
 454     sanitizers.append('undefined')
 455 if GetOption('with_asan'):
 456     # Available for gcc >= 5 or llvm >= 3.1 both a requirement
 457     # by the build system
 458     sanitizers.append('address')
 459     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 460     suppressions_opt = 'suppressions=%s' % suppressions_file
 461     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 462                                             'print_suppressions=0'])
 463     print()
 464     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 465             'environment variable to "%s" when running gem5' %
 466             suppressions_opt)
 467     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 468     print()
 469 if sanitizers:
 470     sanitizers = ','.join(sanitizers)
 471     if main['GCC'] or main['CLANG']:
 472         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 473                              '-fno-omit-frame-pointer'],
 474                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 475     else:
 476         warning("Don't know how to enable %s sanitizer(s) for your "
 477                 "compiler." % sanitizers)
 478
 479 # Set up common yacc/bison flags (needed for Ruby)
 480 main['YACCFLAGS'] = '-d'
 481 main['YACCHXXFILESUFFIX'] = '.hh'
 482
 483 # Do this after we save setting back, or else we'll tack on an
 484 # extra 'qdo' every time we run scons.
 485 if main['BATCH']:
 486     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 487     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 488     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 489     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 490     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 491
 492 if sys.platform == 'cygwin':
 493     # cygwin has some header file issues...
 494     main.Append(CCFLAGS=["-Wno-uninitialized"])
 495
 496
 497 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 498
 499 # Check for the protobuf compiler
 500 try:
 501     main['HAVE_PROTOC'] = True
 502     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 503
 504     # First two words should be "libprotoc x.y.z"
 505     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 506         warning('Protocol buffer compiler (protoc) not found.\n'
 507                 'Please install protobuf-compiler for tracing support.')
 508         main['HAVE_PROTOC'] = False
 509     else:
 510         # Based on the availability of the compress stream wrappers,
 511         # require 2.1.0
 512         min_protoc_version = '2.1.0'
 513         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 514             warning('protoc version', min_protoc_version,
 515                     'or newer required.\n'
 516                     'Installed version:', protoc_version[1])
 517             main['HAVE_PROTOC'] = False
 518         else:
 519             # Attempt to determine the appropriate include path and
 520             # library path using pkg-config, that means we also need to
 521             # check for pkg-config. Note that it is possible to use
 522             # protobuf without the involvement of pkg-config. Later on we
 523             # check go a library config check and at that point the test
 524             # will fail if libprotobuf cannot be found.
 525             if have_pkg_config:
 526                 try:
 527                     # Attempt to establish what linking flags to add for
 528                     # protobuf
 529                     # using pkg-config
 530                     main.ParseConfig(
 531                             'pkg-config --cflags --libs-only-L protobuf')
 532                 except:
 533                     warning('pkg-config could not get protobuf flags.')
 534 except Exception as e:
 535     warning('While checking protoc version:', str(e))
 536     main['HAVE_PROTOC'] = False
 537
 538 # Check for 'timeout' from GNU coreutils. If present, regressions will
 539 # be run with a time limit. We require version 8.13 since we rely on
 540 # support for the '--foreground' option.
 541 if sys.platform.startswith('freebsd'):
 542     timeout_lines = readCommand(['gtimeout', '--version'],
 543                                 exception='').splitlines()
 544 else:
 545     timeout_lines = readCommand(['timeout', '--version'],
 546                                 exception='').splitlines()
 547 # Get the first line and tokenize it
 548 timeout_version = timeout_lines[0].split() if timeout_lines else []
 549 main['TIMEOUT'] =  timeout_version and \
 550     compareVersions(timeout_version[-1], '8.13') >= 0
 551
 552 # Add a custom Check function to test for structure members.
 553 def CheckMember(context, include, decl, member, include_quotes="<>"):
 554     context.Message("Checking for member %s in %s..." %
 555                     (member, decl))
 556     text = """
 557 #include %(header)s
 558 int main(){
 559   %(decl)s test;
 560   (void)test.%(member)s;
 561   return 0;
 562 };
 563 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 564         "decl" : decl,
 565         "member" : member,
 566         }
 567
 568     ret = context.TryCompile(text, extension=".cc")
 569     context.Result(ret)
 570     return ret
 571
 572 # Platform-specific configuration.  Note again that we assume that all
 573 # builds under a given build root run on the same host platform.
 574 conf = Configure(main,
 575                  conf_dir = joinpath(build_root, '.scons_config'),
 576                  log_file = joinpath(build_root, 'scons_config.log'),
 577                  custom_tests = {
 578         'CheckMember' : CheckMember,
 579         })
 580
 581 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 582 try:
 583     import platform
 584     uname = platform.uname()
 585     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 586         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 587             main.Append(CCFLAGS=['-arch', 'x86_64'])
 588             main.Append(CFLAGS=['-arch', 'x86_64'])
 589             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 590             main.Append(ASFLAGS=['-arch', 'x86_64'])
 591 except:
 592     pass
 593
 594 # Recent versions of scons substitute a "Null" object for Configure()
 595 # when configuration isn't necessary, e.g., if the "--help" option is
 596 # present.  Unfortuantely this Null object always returns false,
 597 # breaking all our configuration checks.  We replace it with our own
 598 # more optimistic null object that returns True instead.
 599 if not conf:
 600     def NullCheck(*args, **kwargs):
 601         return True
 602
 603     class NullConf:
 604         def __init__(self, env):
 605             self.env = env
 606         def Finish(self):
 607             return self.env
 608         def __getattr__(self, mname):
 609             return NullCheck
 610
 611     conf = NullConf(main)
 612
 613 # Cache build files in the supplied directory.
 614 if main['M5_BUILD_CACHE']:
 615     print('Using build cache located at', main['M5_BUILD_CACHE'])
 616     CacheDir(main['M5_BUILD_CACHE'])
 617
 618 main['USE_PYTHON'] = not GetOption('without_python')
 619 if main['USE_PYTHON']:
 620     # Find Python include and library directories for embedding the
 621     # interpreter. We rely on python-config to resolve the appropriate
 622     # includes and linker flags. ParseConfig does not seem to understand
 623     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 624     # we add them explicitly below. If you want to link in an alternate
 625     # version of python, see above for instructions on how to invoke
 626     # scons with the appropriate PATH set.
 627
 628     python_config = main.Detect(main['PYTHON_CONFIG'])
 629     if python_config is None:
 630         error("Can't find a suitable python-config, tried %s" % \
 631               main['PYTHON_CONFIG'])
 632
 633     print("Info: Using Python config: %s" % (python_config, ))
 634     if python_config != 'python3-config':
 635         warning('python3-config could not be found.\n'
 636                 'Future releases of gem5 will drop support for python2.')
 637
 638     py_includes = readCommand([python_config, '--includes'],
 639                               exception='').split()
 640     py_includes = list(filter(
 641         lambda s: match(r'.*\/include\/.*',s), py_includes))
 642     # Strip the -I from the include folders before adding them to the
 643     # CPPPATH
 644     py_includes = list(map(
 645         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 646     main.Append(CPPPATH=py_includes)
 647
 648     # Read the linker flags and split them into libraries and other link
 649     # flags. The libraries are added later through the call the CheckLib.
 650     # Note: starting in Python 3.8 the --embed flag is required to get the
 651     # -lpython3.8 linker flag
 652     retcode, cmd_stdout = readCommandWithReturn(
 653         [python_config, '--ldflags', '--embed'], exception='')
 654     if retcode != 0:
 655         # If --embed isn't detected then we're running python <3.8
 656         retcode, cmd_stdout = readCommandWithReturn(
 657             [python_config, '--ldflags'], exception='')
 658
 659     # Checking retcode again
 660     if retcode != 0:
 661         error("Failing on python-config --ldflags command")
 662
 663     py_ld_flags = cmd_stdout.split()
 664
 665     py_libs = []
 666     for lib in py_ld_flags:
 667          if not lib.startswith('-l'):
 668              main.Append(LINKFLAGS=[lib])
 669          else:
 670              lib = lib[2:]
 671              if lib not in py_libs:
 672                  py_libs.append(lib)
 673
 674     # verify that this stuff works
 675     if not conf.CheckHeader('Python.h', '<>'):
 676         error("Check failed for Python.h header in",
 677                 ' '.join(py_includes), "\n"
 678               "Two possible reasons:\n"
 679               "1. Python headers are not installed (You can install the "
 680               "package python-dev on Ubuntu and RedHat)\n"
 681               "2. SCons is using a wrong C compiler. This can happen if "
 682               "CC has the wrong value.\n"
 683               "CC = %s" % main['CC'])
 684
 685     for lib in py_libs:
 686         if not conf.CheckLib(lib):
 687             error("Can't find library %s required by python." % lib)
 688
 689 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
 690 # Bare minimum environment that only includes python
 691 marshal_env = main.Clone()
 692 marshal_env.Append(CCFLAGS='$MARSHAL_CCFLAGS_EXTRA')
 693 marshal_env.Append(LINKFLAGS='$MARSHAL_LDFLAGS_EXTRA')
 694
 695 # On Solaris you need to use libsocket for socket ops
 696 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 697    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 698                                   'C++', 'accept(0,0,0);'):
 699        error("Can't find library with socket calls (e.g. accept()).")
 700
 701 # Check for zlib.  If the check passes, libz will be automatically
 702 # added to the LIBS environment variable.
 703 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 704     error('Did not find needed zlib compression library '
 705           'and/or zlib.h header file.\n'
 706           'Please install zlib and try again.')
 707
 708 # If we have the protobuf compiler, also make sure we have the
 709 # development libraries. If the check passes, libprotobuf will be
 710 # automatically added to the LIBS environment variable. After
 711 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 712 # got both protoc and libprotobuf available.
 713 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 714     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 715                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 716
 717 # Valgrind gets much less confused if you tell it when you're using
 718 # alternative stacks.
 719 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 720
 721 # If we have the compiler but not the library, print another warning.
 722 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 723     warning('Did not find protocol buffer library and/or headers.\n'
 724             'Please install libprotobuf-dev for tracing support.')
 725
 726 # Check for librt.
 727 have_posix_clock = \
 728     conf.CheckLibWithHeader(None, 'time.h', 'C',
 729                             'clock_nanosleep(0,0,NULL,NULL);') or \
 730     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 731                             'clock_nanosleep(0,0,NULL,NULL);')
 732
 733 have_posix_timers = \
 734     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 735                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 736
 737 if not GetOption('without_tcmalloc'):
 738     if conf.CheckLib('tcmalloc'):
 739         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 740     elif conf.CheckLib('tcmalloc_minimal'):
 741         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 742     else:
 743         warning("You can get a 12% performance improvement by "
 744                 "installing tcmalloc (libgoogle-perftools-dev package "
 745                 "on Ubuntu or RedHat).")
 746
 747
 748 # Detect back trace implementations. The last implementation in the
 749 # list will be used by default.
 750 backtrace_impls = [ "none" ]
 751
 752 backtrace_checker = 'char temp;' + \
 753     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 754 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 755     backtrace_impls.append("glibc")
 756 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 757                              backtrace_checker):
 758     # NetBSD and FreeBSD need libexecinfo.
 759     backtrace_impls.append("glibc")
 760     main.Append(LIBS=['execinfo'])
 761
 762 if backtrace_impls[-1] == "none":
 763     default_backtrace_impl = "none"
 764     warning("No suitable back trace implementation found.")
 765
 766 if not have_posix_clock:
 767     warning("Can't find library for POSIX clocks.")
 768
 769 # Check for <fenv.h> (C99 FP environment control)
 770 have_fenv = conf.CheckHeader('fenv.h', '<>')
 771 if not have_fenv:
 772     warning("Header file <fenv.h> not found.\n"
 773             "This host has no IEEE FP rounding mode control.")
 774
 775 # Check for <png.h> (libpng library needed if wanting to dump
 776 # frame buffer image in png format)
 777 have_png = conf.CheckHeader('png.h', '<>')
 778 if not have_png:
 779     warning("Header file <png.h> not found.\n"
 780             "This host has no libpng library.\n"
 781             "Disabling support for PNG framebuffers.")
 782
 783 # Check if we should enable KVM-based hardware virtualization. The API
 784 # we rely on exists since version 2.6.36 of the kernel, but somehow
 785 # the KVM_API_VERSION does not reflect the change. We test for one of
 786 # the types as a fall back.
 787 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 788 if not have_kvm:
 789     print("Info: Compatible header file <linux/kvm.h> not found, "
 790           "disabling KVM support.")
 791
 792 # Check if the TUN/TAP driver is available.
 793 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 794 if not have_tuntap:
 795     print("Info: Compatible header file <linux/if_tun.h> not found.")
 796
 797 # x86 needs support for xsave. We test for the structure here since we
 798 # won't be able to run new tests by the time we know which ISA we're
 799 # targeting.
 800 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 801                                     '#include <linux/kvm.h>') != 0
 802
 803 # Check if the requested target ISA is compatible with the host
 804 def is_isa_kvm_compatible(isa):
 805     try:
 806         import platform
 807         host_isa = platform.machine()
 808     except:
 809         warning("Failed to determine host ISA.")
 810         return False
 811
 812     if not have_posix_timers:
 813         warning("Can not enable KVM, host seems to lack support "
 814                 "for POSIX timers")
 815         return False
 816
 817     if isa == "arm":
 818         return host_isa in ( "armv7l", "aarch64" )
 819     elif isa == "x86":
 820         if host_isa != "x86_64":
 821             return False
 822
 823         if not have_kvm_xsave:
 824             warning("KVM on x86 requires xsave support in kernel headers.")
 825             return False
 826
 827         return True
 828     else:
 829         return False
 830
 831
 832 # Check if the exclude_host attribute is available. We want this to
 833 # get accurate instruction counts in KVM.
 834 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 835     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 836
 837 def check_hdf5():
 838     return \
 839         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 840                                 'H5Fcreate("", 0, 0, 0);') and \
 841         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 842                                 'H5::H5File("", 0);')
 843
 844 def check_hdf5_pkg(name):
 845     print("Checking for %s using pkg-config..." % name, end="")
 846     if not have_pkg_config:
 847         print(" pkg-config not found")
 848         return False
 849
 850     try:
 851         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 852         print(" yes")
 853         return True
 854     except:
 855         print(" no")
 856         return False
 857
 858 # Check if there is a pkg-config configuration for hdf5. If we find
 859 # it, setup the environment to enable linking and header inclusion. We
 860 # don't actually try to include any headers or link with hdf5 at this
 861 # stage.
 862 if not check_hdf5_pkg('hdf5-serial'):
 863     check_hdf5_pkg('hdf5')
 864
 865 # Check if the HDF5 libraries can be found. This check respects the
 866 # include path and library path provided by pkg-config. We perform
 867 # this check even if there isn't a pkg-config configuration for hdf5
 868 # since some installations don't use pkg-config.
 869 have_hdf5 = check_hdf5()
 870 if not have_hdf5:
 871     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 872     print("         HDF5 support.")
 873
 874 ######################################################################
 875 #
 876 # Finish the configuration
 877 #
 878 main = conf.Finish()
 879
 880 ######################################################################
 881 #
 882 # Collect all non-global variables
 883 #
 884
 885 # Define the universe of supported ISAs
 886 all_isa_list = [ ]
 887 all_gpu_isa_list = [ ]
 888 Export('all_isa_list')
 889 Export('all_gpu_isa_list')
 890
 891 class CpuModel(object):
 892     '''The CpuModel class encapsulates everything the ISA parser needs to
 893     know about a particular CPU model.'''
 894
 895     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 896     dict = {}
 897
 898     # Constructor.  Automatically adds models to CpuModel.dict.
 899     def __init__(self, name, default=False):
 900         self.name = name           # name of model
 901
 902         # This cpu is enabled by default
 903         self.default = default
 904
 905         # Add self to dict
 906         if name in CpuModel.dict:
 907             raise AttributeError("CpuModel '%s' already registered" % name)
 908         CpuModel.dict[name] = self
 909
 910 Export('CpuModel')
 911
 912 # Sticky variables get saved in the variables file so they persist from
 913 # one invocation to the next (unless overridden, in which case the new
 914 # value becomes sticky).
 915 sticky_vars = Variables(args=ARGUMENTS)
 916 Export('sticky_vars')
 917
 918 # Sticky variables that should be exported
 919 export_vars = []
 920 Export('export_vars')
 921
 922 # For Ruby
 923 all_protocols = []
 924 Export('all_protocols')
 925 protocol_dirs = []
 926 Export('protocol_dirs')
 927 slicc_includes = []
 928 Export('slicc_includes')
 929
 930 # Walk the tree and execute all SConsopts scripts that wil add to the
 931 # above variables
 932 if GetOption('verbose'):
 933     print("Reading SConsopts")
 934 for bdir in [ base_dir ] + extras_dir_list:
 935     if not isdir(bdir):
 936         error("Directory '%s' does not exist." % bdir)
 937     for root, dirs, files in os.walk(bdir):
 938         if 'SConsopts' in files:
 939             if GetOption('verbose'):
 940                 print("Reading", joinpath(root, 'SConsopts'))
 941             SConscript(joinpath(root, 'SConsopts'))
 942
 943 all_isa_list.sort()
 944 all_gpu_isa_list.sort()
 945
 946 sticky_vars.AddVariables(
 947     EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list),
 948     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'gcn3', all_gpu_isa_list),
 949     ListVariable('CPU_MODELS', 'CPU models',
 950                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 951                  sorted(CpuModel.dict.keys())),
 952     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 953                  False),
 954     BoolVariable('USE_SSE2',
 955                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 956                  False),
 957     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 958     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 959     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 960     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 961                  have_kvm),
 962     BoolVariable('USE_TUNTAP',
 963                  'Enable using a tap device to bridge to the host network',
 964                  have_tuntap),
 965     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
 966     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
 967                   all_protocols),
 968     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
 969                  backtrace_impls[-1], backtrace_impls),
 970     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
 971                  64),
 972     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
 973     )
 974
 975 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 976 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA',
 977                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
 978                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
 979                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
 980                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
 981
 982 ###################################################
 983 #
 984 # Define a SCons builder for configuration flag headers.
 985 #
 986 ###################################################
 987
 988 # This function generates a config header file that #defines the
 989 # variable symbol to the current variable setting (0 or 1).  The source
 990 # operands are the name of the variable and a Value node containing the
 991 # value of the variable.
 992 def build_config_file(target, source, env):
 993     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
 994     with open(str(target[0]), 'w') as f:
 995         print('#define', variable, value, file=f)
 996     return None
 997
 998 # Combine the two functions into a scons Action object.
 999 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1000
1001 # The emitter munges the source & target node lists to reflect what
1002 # we're really doing.
1003 def config_emitter(target, source, env):
1004     # extract variable name from Builder arg
1005     variable = str(target[0])
1006     # True target is config header file
1007     target = joinpath('config', variable.lower() + '.hh')
1008     val = env[variable]
1009     if isinstance(val, bool):
1010         # Force value to 0/1
1011         val = int(val)
1012     elif isinstance(val, str):
1013         val = '"' + val + '"'
1014
1015     # Sources are variable name & value (packaged in SCons Value nodes)
1016     return ([target], [Value(variable), Value(val)])
1017
1018 config_builder = Builder(emitter = config_emitter, action = config_action)
1019
1020 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1021
1022 ###################################################
1023 #
1024 # Builders for static and shared partially linked object files.
1025 #
1026 ###################################################
1027
1028 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1029                                  src_suffix='$OBJSUFFIX',
1030                                  src_builder=['StaticObject', 'Object'],
1031                                  LINKFLAGS='$PLINKFLAGS',
1032                                  LIBS='')
1033
1034 def partial_shared_emitter(target, source, env):
1035     for tgt in target:
1036         tgt.attributes.shared = 1
1037     return (target, source)
1038 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1039                                  emitter=partial_shared_emitter,
1040                                  src_suffix='$SHOBJSUFFIX',
1041                                  src_builder='SharedObject',
1042                                  SHLINKFLAGS='$PSHLINKFLAGS',
1043                                  LIBS='')
1044
1045 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1046                          'PartialStatic' : partial_static_builder })
1047
1048 def add_local_rpath(env, *targets):
1049     '''Set up an RPATH for a library which lives in the build directory.
1050
1051     The construction environment variable BIN_RPATH_PREFIX should be set to
1052     the relative path of the build directory starting from the location of the
1053     binary.'''
1054     for target in targets:
1055         target = env.Entry(target)
1056         if not isinstance(target, SCons.Node.FS.Dir):
1057             target = target.dir
1058         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1059         components = [
1060             '\\$$ORIGIN',
1061             '${BIN_RPATH_PREFIX}',
1062             relpath
1063         ]
1064         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1065
1066 if sys.platform != "darwin":
1067     main.Append(LINKFLAGS=Split('-z origin'))
1068
1069 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1070
1071 # builds in ext are shared across all configs in the build root.
1072 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1073 ext_build_dirs = []
1074 for root, dirs, files in os.walk(ext_dir):
1075     if 'SConscript' in files:
1076         build_dir = os.path.relpath(root, ext_dir)
1077         ext_build_dirs.append(build_dir)
1078         main.SConscript(joinpath(root, 'SConscript'),
1079                         variant_dir=joinpath(build_root, build_dir))
1080
1081 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1082 Export('gdb_xml_dir')
1083
1084 ###################################################
1085 #
1086 # This builder and wrapper method are used to set up a directory with
1087 # switching headers. Those are headers which are in a generic location and
1088 # that include more specific headers from a directory chosen at build time
1089 # based on the current build settings.
1090 #
1091 ###################################################
1092
1093 def build_switching_header(target, source, env):
1094     path = str(target[0])
1095     subdir = str(source[0])
1096     dp, fp = os.path.split(path)
1097     dp = os.path.relpath(os.path.realpath(dp),
1098                          os.path.realpath(env['BUILDDIR']))
1099     with open(path, 'w') as hdr:
1100         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1101
1102 switching_header_action = MakeAction(build_switching_header,
1103                                      Transform('GENERATE'))
1104
1105 switching_header_builder = Builder(action=switching_header_action,
1106                                    source_factory=Value,
1107                                    single_source=True)
1108
1109 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1110
1111 def switching_headers(self, headers, source):
1112     for header in headers:
1113         self.SwitchingHeader(header, source)
1114
1115 main.AddMethod(switching_headers, 'SwitchingHeaders')
1116
1117 ###################################################
1118 #
1119 # Define build environments for selected configurations.
1120 #
1121 ###################################################
1122
1123 for variant_path in variant_paths:
1124     if not GetOption('silent'):
1125         print("Building in", variant_path)
1126
1127     # Make a copy of the build-root environment to use for this config.
1128     env = main.Clone()
1129     env['BUILDDIR'] = variant_path
1130
1131     # variant_dir is the tail component of build path, and is used to
1132     # determine the build parameters (e.g., 'X86')
1133     (build_root, variant_dir) = splitpath(variant_path)
1134
1135     # Set env variables according to the build directory config.
1136     sticky_vars.files = []
1137     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1138     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1139     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1140     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1141     if isfile(current_vars_file):
1142         sticky_vars.files.append(current_vars_file)
1143         if not GetOption('silent'):
1144             print("Using saved variables file %s" % current_vars_file)
1145     elif variant_dir in ext_build_dirs:
1146         # Things in ext are built without a variant directory.
1147         continue
1148     else:
1149         # Build dir-specific variables file doesn't exist.
1150
1151         # Make sure the directory is there so we can create it later
1152         opt_dir = dirname(current_vars_file)
1153         if not isdir(opt_dir):
1154             mkdir(opt_dir)
1155
1156         # Get default build variables from source tree.  Variables are
1157         # normally determined by name of $VARIANT_DIR, but can be
1158         # overridden by '--default=' arg on command line.
1159         default = GetOption('default')
1160         opts_dir = joinpath(main.root.abspath, 'build_opts')
1161         if default:
1162             default_vars_files = [joinpath(build_root, 'variables', default),
1163                                   joinpath(opts_dir, default)]
1164         else:
1165             default_vars_files = [joinpath(opts_dir, variant_dir)]
1166         existing_files = list(filter(isfile, default_vars_files))
1167         if existing_files:
1168             default_vars_file = existing_files[0]
1169             sticky_vars.files.append(default_vars_file)
1170             print("Variables file %s not found,\n  using defaults in %s"
1171                   % (current_vars_file, default_vars_file))
1172         else:
1173             error("Cannot find variables file %s or default file(s) %s"
1174                   % (current_vars_file, ' or '.join(default_vars_files)))
1175             Exit(1)
1176
1177     # Apply current variable settings to env
1178     sticky_vars.Update(env)
1179
1180     Help('''
1181 Build variables for {dir}:
1182 {help}
1183 '''.format(dir=variant_dir, help=sticky_vars.GenerateHelpText(env)),
1184          append=True)
1185
1186     # Process variable settings.
1187
1188     if not have_fenv and env['USE_FENV']:
1189         warning("<fenv.h> not available; forcing USE_FENV to False in",
1190                 variant_dir + ".")
1191         env['USE_FENV'] = False
1192
1193     if not env['USE_FENV']:
1194         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1195                 "FP results may deviate slightly from other platforms.")
1196
1197     if not have_png and env['USE_PNG']:
1198         warning("<png.h> not available; forcing USE_PNG to False in",
1199                 variant_dir + ".")
1200         env['USE_PNG'] = False
1201
1202     if env['USE_PNG']:
1203         env.Append(LIBS=['png'])
1204
1205     if env['EFENCE']:
1206         env.Append(LIBS=['efence'])
1207
1208     if env['USE_KVM']:
1209         if not have_kvm:
1210             warning("Can not enable KVM, host seems to lack KVM support")
1211             env['USE_KVM'] = False
1212         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1213             print("Info: KVM support disabled due to unsupported host and "
1214                   "target ISA combination")
1215             env['USE_KVM'] = False
1216
1217     if env['USE_TUNTAP']:
1218         if not have_tuntap:
1219             warning("Can't connect EtherTap with a tap device.")
1220             env['USE_TUNTAP'] = False
1221
1222     if env['BUILD_GPU']:
1223         env.Append(CPPDEFINES=['BUILD_GPU'])
1224
1225     # Warn about missing optional functionality
1226     if env['USE_KVM']:
1227         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1228             warning("perf_event headers lack support for the exclude_host "
1229                     "attribute. KVM instruction counts will be inaccurate.")
1230
1231     # Save sticky variable settings back to current variables file
1232     sticky_vars.Save(current_vars_file, env)
1233
1234     if env['USE_SSE2']:
1235         env.Append(CCFLAGS=['-msse2'])
1236
1237     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1238     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1239
1240     # The src/SConscript file sets up the build rules in 'env' according
1241     # to the configured variables.  It returns a list of environments,
1242     # one for each variant build (debug, opt, etc.)
1243     SConscript('src/SConscript', variant_dir=variant_path,
1244                exports=['env', 'marshal_env'])
1245
1246 atexit.register(summarize_warnings)