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 help_texts = {
 103     "options" : "",
 104     "global_vars" : "",
 105     "local_vars" : ""
 106 }
 107
 108 Export("help_texts")
 109
 110
 111 # There's a bug in scons in that (1) by default, the help texts from
 112 # AddOption() are supposed to be displayed when you type 'scons -h'
 113 # and (2) you can override the help displayed by 'scons -h' using the
 114 # Help() function, but these two features are incompatible: once
 115 # you've overridden the help text using Help(), there's no way to get
 116 # at the help texts from AddOptions.  See:
 117 #     https://github.com/SCons/scons/issues/2356
 118 #     https://github.com/SCons/scons/issues/2611
 119 # This hack lets us extract the help text from AddOptions and
 120 # re-inject it via Help().  Ideally someday this bug will be fixed and
 121 # we can just use AddOption directly.
 122 def AddLocalOption(*args, **kwargs):
 123     col_width = 30
 124
 125     help = "  " + ", ".join(args)
 126     if "help" in kwargs:
 127         length = len(help)
 128         if length >= col_width:
 129             help += "\n" + " " * col_width
 130         else:
 131             help += " " * (col_width - length)
 132         help += kwargs["help"]
 133     help_texts["options"] += help + "\n"
 134
 135     AddOption(*args, **kwargs)
 136
 137 AddLocalOption('--colors', dest='use_colors', action='store_true',
 138                help="Add color to abbreviated scons output")
 139 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 140                help="Don't add color to abbreviated scons output")
 141 AddLocalOption('--with-cxx-config', action='store_true',
 142                help="Build with support for C++-based configuration")
 143 AddLocalOption('--default',
 144                help='Override which build_opts file to use for defaults')
 145 AddLocalOption('--ignore-style', action='store_true',
 146                help='Disable style checking hooks')
 147 AddLocalOption('--gold-linker', action='store_true',
 148                help='Use the gold linker')
 149 AddLocalOption('--no-lto', action='store_true',
 150                help='Disable Link-Time Optimization for fast')
 151 AddLocalOption('--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('--verbose', action='store_true',
 155                help='Print full tool command lines')
 156 AddLocalOption('--without-python', action='store_true',
 157                help='Build without Python configuration support')
 158 AddLocalOption('--without-tcmalloc', action='store_true',
 159                help='Disable linking against tcmalloc')
 160 AddLocalOption('--with-ubsan', action='store_true',
 161                help='Build with Undefined Behavior Sanitizer if available')
 162 AddLocalOption('--with-asan', action='store_true',
 163                help='Build with Address Sanitizer if available')
 164 AddLocalOption('--with-systemc-tests', action='store_true',
 165                help='Build systemc tests')
 166
 167 from gem5_scons import Transform, error, warning, summarize_warnings
 168
 169 if GetOption('no_lto') and GetOption('force_lto'):
 170     error('--no-lto and --force-lto are mutually exclusive')
 171
 172 ########################################################################
 173 #
 174 # Set up the main build environment.
 175 #
 176 ########################################################################
 177
 178 main = Environment()
 179
 180 from gem5_scons.util import get_termcap
 181 termcap = get_termcap()
 182
 183 main_dict_keys = main.Dictionary().keys()
 184
 185 # Check that we have a C/C++ compiler
 186 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 187     error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 188
 189 ###################################################
 190 #
 191 # Figure out which configurations to set up based on the path(s) of
 192 # the target(s).
 193 #
 194 ###################################################
 195
 196 # Find default configuration & binary.
 197 Default(environ.get('M5_DEFAULT_BINARY', 'build/ARM/gem5.debug'))
 198
 199 # helper function: find last occurrence of element in list
 200 def rfind(l, elt, offs = -1):
 201     for i in range(len(l)+offs, 0, -1):
 202         if l[i] == elt:
 203             return i
 204     raise ValueError("element not found")
 205
 206 # Take a list of paths (or SCons Nodes) and return a list with all
 207 # paths made absolute and ~-expanded.  Paths will be interpreted
 208 # relative to the launch directory unless a different root is provided
 209 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 210     return [abspath(joinpath(root, expanduser(str(p))))
 211             for p in path_list]
 212
 213 # Each target must have 'build' in the interior of the path; the
 214 # directory below this will determine the build parameters.  For
 215 # example, for target 'foo/bar/build/X86/arch/x86/blah.do' we
 216 # recognize that X86 specifies the configuration because it
 217 # follow 'build' in the build path.
 218
 219 # The funky assignment to "[:]" is needed to replace the list contents
 220 # in place rather than reassign the symbol to a new list, which
 221 # doesn't work (obviously!).
 222 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 223
 224 # Generate a list of the unique build roots and configs that the
 225 # collected targets reference.
 226 variant_paths = []
 227 build_root = None
 228 for t in BUILD_TARGETS:
 229     path_dirs = t.split('/')
 230     try:
 231         build_top = rfind(path_dirs, 'build', -2)
 232     except:
 233         error("No non-leaf 'build' dir found on target path.", t)
 234     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 235     if not build_root:
 236         build_root = this_build_root
 237     else:
 238         if this_build_root != build_root:
 239             error("build targets not under same build root\n"
 240                   "  %s\n  %s" % (build_root, this_build_root))
 241     variant_path = joinpath('/',*path_dirs[:build_top+2])
 242     if variant_path not in variant_paths:
 243         variant_paths.append(variant_path)
 244
 245 # Make sure build_root exists (might not if this is the first build there)
 246 if not isdir(build_root):
 247     mkdir(build_root)
 248 main['BUILDROOT'] = build_root
 249
 250 Export('main')
 251
 252 main.SConsignFile(joinpath(build_root, "sconsign"))
 253
 254 # Default duplicate option is to use hard links, but this messes up
 255 # when you use emacs to edit a file in the target dir, as emacs moves
 256 # file to file~ then copies to file, breaking the link.  Symbolic
 257 # (soft) links work better.
 258 main.SetOption('duplicate', 'soft-copy')
 259
 260 #
 261 # Set up global sticky variables... these are common to an entire build
 262 # tree (not specific to a particular build like X86)
 263 #
 264
 265 global_vars_file = joinpath(build_root, 'variables.global')
 266
 267 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 268
 269 global_vars.AddVariables(
 270     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 271     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 272     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 273     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 274     ('MARSHAL_CCFLAGS_EXTRA', 'Extra C and C++ marshal compiler flags', ''),
 275     ('MARSHAL_LDFLAGS_EXTRA', 'Extra marshal linker flags', ''),
 276     ('PYTHON_CONFIG', 'Python config binary to use',
 277      [ 'python2.7-config', 'python-config', 'python3-config' ]),
 278     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 279     ('BATCH', 'Use batch pool for build and tests', False),
 280     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 281     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 282     ('EXTRAS', 'Add extra directories to the compilation', '')
 283     )
 284
 285 # Update main environment with values from ARGUMENTS & global_vars_file
 286 global_vars.Update(main)
 287 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 288
 289 # Save sticky variable settings back to current variables file
 290 global_vars.Save(global_vars_file, main)
 291
 292 # Parse EXTRAS variable to build list of all directories where we're
 293 # look for sources etc.  This list is exported as extras_dir_list.
 294 base_dir = main.srcdir.abspath
 295 if main['EXTRAS']:
 296     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 297 else:
 298     extras_dir_list = []
 299
 300 Export('base_dir')
 301 Export('extras_dir_list')
 302
 303 # the ext directory should be on the #includes path
 304 main.Append(CPPPATH=[Dir('ext')])
 305
 306 # Add shared top-level headers
 307 main.Prepend(CPPPATH=Dir('include'))
 308
 309 if GetOption('verbose'):
 310     def MakeAction(action, string, *args, **kwargs):
 311         return Action(action, *args, **kwargs)
 312 else:
 313     MakeAction = Action
 314     main['CCCOMSTR']        = Transform("CC")
 315     main['CXXCOMSTR']       = Transform("CXX")
 316     main['ASCOMSTR']        = Transform("AS")
 317     main['ARCOMSTR']        = Transform("AR", 0)
 318     main['LINKCOMSTR']      = Transform("LINK", 0)
 319     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 320     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 321     main['M4COMSTR']        = Transform("M4")
 322     main['SHCCCOMSTR']      = Transform("SHCC")
 323     main['SHCXXCOMSTR']     = Transform("SHCXX")
 324 Export('MakeAction')
 325
 326 # Initialize the Link-Time Optimization (LTO) flags
 327 main['LTO_CCFLAGS'] = []
 328 main['LTO_LDFLAGS'] = []
 329
 330 # According to the readme, tcmalloc works best if the compiler doesn't
 331 # assume that we're using the builtin malloc and friends. These flags
 332 # are compiler-specific, so we need to set them after we detect which
 333 # compiler we're using.
 334 main['TCMALLOC_CCFLAGS'] = []
 335
 336 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 337 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 338
 339 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 340 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 341 if main['GCC'] + main['CLANG'] > 1:
 342     error('Two compilers enabled at once?')
 343
 344 # Set up default C++ compiler flags
 345 if main['GCC'] or main['CLANG']:
 346     # As gcc and clang share many flags, do the common parts here
 347     main.Append(CCFLAGS=['-pipe'])
 348     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 349     # Enable -Wall and -Wextra and then disable the few warnings that
 350     # we consistently violate
 351     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 352                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 353     # We always compile using C++11
 354     main.Append(CXXFLAGS=['-std=c++11'])
 355     if sys.platform.startswith('freebsd'):
 356         main.Append(CCFLAGS=['-I/usr/local/include'])
 357         main.Append(CXXFLAGS=['-I/usr/local/include'])
 358
 359     # On Mac OS X/Darwin the default linker doesn't support the
 360     # option --as-needed
 361     if sys.platform != "darwin":
 362         main.Append(LINKFLAGS='-Wl,--as-needed')
 363     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 364     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 365     if GetOption('gold_linker'):
 366         main.Append(LINKFLAGS='-fuse-ld=gold')
 367     main['PLINKFLAGS'] = main.get('LINKFLAGS')
 368     shared_partial_flags = ['-r', '-nostdlib']
 369     main.Append(PSHLINKFLAGS=shared_partial_flags)
 370     main.Append(PLINKFLAGS=shared_partial_flags)
 371
 372     # Treat warnings as errors but white list some warnings that we
 373     # want to allow (e.g., deprecation warnings).
 374     main.Append(CCFLAGS=['-Werror',
 375                          '-Wno-error=deprecated-declarations',
 376                          '-Wno-error=deprecated',
 377                         ])
 378 else:
 379     error('\n'.join((
 380           "Don't know what compiler options to use for your compiler.",
 381           "compiler: " + main['CXX'],
 382           "version: " + CXX_version.replace('\n', '<nl>') if
 383                 CXX_version else 'COMMAND NOT FOUND!',
 384           "If you're trying to use a compiler other than GCC",
 385           "or clang, there appears to be something wrong with your",
 386           "environment.",
 387           "",
 388           "If you are trying to use a compiler other than those listed",
 389           "above you will need to ease fix SConstruct and ",
 390           "src/SConscript to support that compiler.")))
 391
 392 if main['GCC']:
 393     # Check for a supported version of gcc. >= 4.8 is chosen for its
 394     # level of c++11 support. See
 395     # http://gcc.gnu.org/projects/cxx0x.html for details.
 396     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 397     if compareVersions(gcc_version, "4.8") < 0:
 398         error('gcc version 4.8 or newer required.\n'
 399               'Installed version:', gcc_version)
 400         Exit(1)
 401
 402     main['GCC_VERSION'] = gcc_version
 403
 404     if compareVersions(gcc_version, '4.9') >= 0:
 405         # Incremental linking with LTO is currently broken in gcc versions
 406         # 4.9 and above. A version where everything works completely hasn't
 407         # yet been identified.
 408         #
 409         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 410         main['BROKEN_INCREMENTAL_LTO'] = True
 411     if compareVersions(gcc_version, '6.0') >= 0:
 412         # gcc versions 6.0 and greater accept an -flinker-output flag which
 413         # selects what type of output the linker should generate. This is
 414         # necessary for incremental lto to work, but is also broken in
 415         # current versions of gcc. It may not be necessary in future
 416         # versions. We add it here since it might be, and as a reminder that
 417         # it exists. It's excluded if lto is being forced.
 418         #
 419         # https://gcc.gnu.org/gcc-6/changes.html
 420         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 421         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 422         if not GetOption('force_lto'):
 423             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 424             main.Append(PLINKFLAGS='-flinker-output=rel')
 425
 426     disable_lto = GetOption('no_lto')
 427     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 428             not GetOption('force_lto'):
 429         warning('Your compiler doesn\'t support incremental linking and lto '
 430                 'at the same time, so lto is being disabled. To force lto on '
 431                 'anyway, use the --force-lto option. That will disable '
 432                 'partial linking.')
 433         disable_lto = True
 434
 435     # Add the appropriate Link-Time Optimization (LTO) flags
 436     # unless LTO is explicitly turned off. Note that these flags
 437     # are only used by the fast target.
 438     if not disable_lto:
 439         # Pass the LTO flag when compiling to produce GIMPLE
 440         # output, we merely create the flags here and only append
 441         # them later
 442         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 443
 444         # Use the same amount of jobs for LTO as we are running
 445         # scons with
 446         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 447
 448     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 449                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 450
 451 elif main['CLANG']:
 452     # Check for a supported version of clang, >= 3.1 is needed to
 453     # support similar features as gcc 4.8. See
 454     # http://clang.llvm.org/cxx_status.html for details
 455     clang_version_re = re.compile(".* version (\d+\.\d+)")
 456     clang_version_match = clang_version_re.search(CXX_version)
 457     if (clang_version_match):
 458         clang_version = clang_version_match.groups()[0]
 459         if compareVersions(clang_version, "3.1") < 0:
 460             error('clang version 3.1 or newer required.\n'
 461                   'Installed version:', clang_version)
 462     else:
 463         error('Unable to determine clang version.')
 464
 465     # clang has a few additional warnings that we disable, extraneous
 466     # parantheses are allowed due to Ruby's printing of the AST,
 467     # finally self assignments are allowed as the generated CPU code
 468     # is relying on this
 469     main.Append(CCFLAGS=['-Wno-parentheses',
 470                          '-Wno-self-assign',
 471                          # Some versions of libstdc++ (4.8?) seem to
 472                          # use struct hash and class hash
 473                          # interchangeably.
 474                          '-Wno-mismatched-tags',
 475                          ])
 476     if compareVersions(clang_version, "10.0") >= 0:
 477         main.Append(CCFLAGS=['-Wno-c99-designator'])
 478
 479     if compareVersions(clang_version, "8.0") >= 0:
 480         main.Append(CCFLAGS=['-Wno-defaulted-function-deleted'])
 481
 482     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 483
 484     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 485     # opposed to libstdc++, as the later is dated.
 486     if sys.platform == "darwin":
 487         main.Append(CXXFLAGS=['-stdlib=libc++'])
 488         main.Append(LIBS=['c++'])
 489
 490     # On FreeBSD we need libthr.
 491     if sys.platform.startswith('freebsd'):
 492         main.Append(LIBS=['thr'])
 493
 494 # Add sanitizers flags
 495 sanitizers=[]
 496 if GetOption('with_ubsan'):
 497     # Only gcc >= 4.9 supports UBSan, so check both the version
 498     # and the command-line option before adding the compiler and
 499     # linker flags.
 500     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 501         sanitizers.append('undefined')
 502 if GetOption('with_asan'):
 503     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 504     # by the build system
 505     sanitizers.append('address')
 506     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 507     suppressions_opt = 'suppressions=%s' % suppressions_file
 508     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 509                                             'print_suppressions=0'])
 510     print()
 511     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 512             'environment variable to "%s" when running gem5' %
 513             suppressions_opt)
 514     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 515     print()
 516 if sanitizers:
 517     sanitizers = ','.join(sanitizers)
 518     if main['GCC'] or main['CLANG']:
 519         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 520                              '-fno-omit-frame-pointer'],
 521                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 522     else:
 523         warning("Don't know how to enable %s sanitizer(s) for your "
 524                 "compiler." % sanitizers)
 525
 526 # Set up common yacc/bison flags (needed for Ruby)
 527 main['YACCFLAGS'] = '-d'
 528 main['YACCHXXFILESUFFIX'] = '.hh'
 529
 530 # Do this after we save setting back, or else we'll tack on an
 531 # extra 'qdo' every time we run scons.
 532 if main['BATCH']:
 533     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 534     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 535     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 536     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 537     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 538
 539 if sys.platform == 'cygwin':
 540     # cygwin has some header file issues...
 541     main.Append(CCFLAGS=["-Wno-uninitialized"])
 542
 543
 544 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 545
 546 # Check for the protobuf compiler
 547 try:
 548     main['HAVE_PROTOC'] = True
 549     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 550
 551     # First two words should be "libprotoc x.y.z"
 552     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 553         warning('Protocol buffer compiler (protoc) not found.\n'
 554                 'Please install protobuf-compiler for tracing support.')
 555         main['HAVE_PROTOC'] = False
 556     else:
 557         # Based on the availability of the compress stream wrappers,
 558         # require 2.1.0
 559         min_protoc_version = '2.1.0'
 560         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 561             warning('protoc version', min_protoc_version,
 562                     'or newer required.\n'
 563                     'Installed version:', protoc_version[1])
 564             main['HAVE_PROTOC'] = False
 565         else:
 566             # Attempt to determine the appropriate include path and
 567             # library path using pkg-config, that means we also need to
 568             # check for pkg-config. Note that it is possible to use
 569             # protobuf without the involvement of pkg-config. Later on we
 570             # check go a library config check and at that point the test
 571             # will fail if libprotobuf cannot be found.
 572             if have_pkg_config:
 573                 try:
 574                     # Attempt to establish what linking flags to add for
 575                     # protobuf
 576                     # using pkg-config
 577                     main.ParseConfig(
 578                             'pkg-config --cflags --libs-only-L protobuf')
 579                 except:
 580                     warning('pkg-config could not get protobuf flags.')
 581 except Exception as e:
 582     warning('While checking protoc version:', str(e))
 583     main['HAVE_PROTOC'] = False
 584
 585 # Check for 'timeout' from GNU coreutils. If present, regressions will
 586 # be run with a time limit. We require version 8.13 since we rely on
 587 # support for the '--foreground' option.
 588 if sys.platform.startswith('freebsd'):
 589     timeout_lines = readCommand(['gtimeout', '--version'],
 590                                 exception='').splitlines()
 591 else:
 592     timeout_lines = readCommand(['timeout', '--version'],
 593                                 exception='').splitlines()
 594 # Get the first line and tokenize it
 595 timeout_version = timeout_lines[0].split() if timeout_lines else []
 596 main['TIMEOUT'] =  timeout_version and \
 597     compareVersions(timeout_version[-1], '8.13') >= 0
 598
 599 # Add a custom Check function to test for structure members.
 600 def CheckMember(context, include, decl, member, include_quotes="<>"):
 601     context.Message("Checking for member %s in %s..." %
 602                     (member, decl))
 603     text = """
 604 #include %(header)s
 605 int main(){
 606   %(decl)s test;
 607   (void)test.%(member)s;
 608   return 0;
 609 };
 610 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 611         "decl" : decl,
 612         "member" : member,
 613         }
 614
 615     ret = context.TryCompile(text, extension=".cc")
 616     context.Result(ret)
 617     return ret
 618
 619 # Platform-specific configuration.  Note again that we assume that all
 620 # builds under a given build root run on the same host platform.
 621 conf = Configure(main,
 622                  conf_dir = joinpath(build_root, '.scons_config'),
 623                  log_file = joinpath(build_root, 'scons_config.log'),
 624                  custom_tests = {
 625         'CheckMember' : CheckMember,
 626         })
 627
 628 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 629 try:
 630     import platform
 631     uname = platform.uname()
 632     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 633         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 634             main.Append(CCFLAGS=['-arch', 'x86_64'])
 635             main.Append(CFLAGS=['-arch', 'x86_64'])
 636             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 637             main.Append(ASFLAGS=['-arch', 'x86_64'])
 638 except:
 639     pass
 640
 641 # Recent versions of scons substitute a "Null" object for Configure()
 642 # when configuration isn't necessary, e.g., if the "--help" option is
 643 # present.  Unfortuantely this Null object always returns false,
 644 # breaking all our configuration checks.  We replace it with our own
 645 # more optimistic null object that returns True instead.
 646 if not conf:
 647     def NullCheck(*args, **kwargs):
 648         return True
 649
 650     class NullConf:
 651         def __init__(self, env):
 652             self.env = env
 653         def Finish(self):
 654             return self.env
 655         def __getattr__(self, mname):
 656             return NullCheck
 657
 658     conf = NullConf(main)
 659
 660 # Cache build files in the supplied directory.
 661 if main['M5_BUILD_CACHE']:
 662     print('Using build cache located at', main['M5_BUILD_CACHE'])
 663     CacheDir(main['M5_BUILD_CACHE'])
 664
 665 main['USE_PYTHON'] = not GetOption('without_python')
 666 if main['USE_PYTHON']:
 667     # Find Python include and library directories for embedding the
 668     # interpreter. We rely on python-config to resolve the appropriate
 669     # includes and linker flags. ParseConfig does not seem to understand
 670     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 671     # we add them explicitly below. If you want to link in an alternate
 672     # version of python, see above for instructions on how to invoke
 673     # scons with the appropriate PATH set.
 674
 675     python_config = main.Detect(main['PYTHON_CONFIG'])
 676     if python_config is None:
 677         error("Can't find a suitable python-config, tried %s" % \
 678               main['PYTHON_CONFIG'])
 679
 680     print("Info: Using Python config: %s" % (python_config, ))
 681     py_includes = readCommand([python_config, '--includes'],
 682                               exception='').split()
 683     py_includes = list(filter(
 684         lambda s: match(r'.*\/include\/.*',s), py_includes))
 685     # Strip the -I from the include folders before adding them to the
 686     # CPPPATH
 687     py_includes = list(map(
 688         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 689     main.Append(CPPPATH=py_includes)
 690
 691     # Read the linker flags and split them into libraries and other link
 692     # flags. The libraries are added later through the call the CheckLib.
 693     # Note: starting in Python 3.8 the --embed flag is required to get the
 694     # -lpython3.8 linker flag
 695     retcode, cmd_stdout = readCommandWithReturn(
 696         [python_config, '--ldflags', '--embed'], exception='')
 697     if retcode != 0:
 698         # If --embed isn't detected then we're running python <3.8
 699         retcode, cmd_stdout = readCommandWithReturn(
 700             [python_config, '--ldflags'], exception='')
 701
 702     # Checking retcode again
 703     if retcode != 0:
 704         error("Failing on python-config --ldflags command")
 705
 706     py_ld_flags = cmd_stdout.split()
 707
 708     py_libs = []
 709     for lib in py_ld_flags:
 710          if not lib.startswith('-l'):
 711              main.Append(LINKFLAGS=[lib])
 712          else:
 713              lib = lib[2:]
 714              if lib not in py_libs:
 715                  py_libs.append(lib)
 716
 717     # verify that this stuff works
 718     if not conf.CheckHeader('Python.h', '<>'):
 719         error("Check failed for Python.h header in",
 720                 ' '.join(py_includes), "\n"
 721               "Two possible reasons:\n"
 722               "1. Python headers are not installed (You can install the "
 723               "package python-dev on Ubuntu and RedHat)\n"
 724               "2. SCons is using a wrong C compiler. This can happen if "
 725               "CC has the wrong value.\n"
 726               "CC = %s" % main['CC'])
 727
 728     for lib in py_libs:
 729         if not conf.CheckLib(lib):
 730             error("Can't find library %s required by python." % lib)
 731
 732 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
 733 # Bare minimum environment that only includes python
 734 marshal_env = main.Clone()
 735 marshal_env.Append(CCFLAGS='$MARSHAL_CCFLAGS_EXTRA')
 736 marshal_env.Append(LINKFLAGS='$MARSHAL_LDFLAGS_EXTRA')
 737
 738 # On Solaris you need to use libsocket for socket ops
 739 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 740    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 741                                   'C++', 'accept(0,0,0);'):
 742        error("Can't find library with socket calls (e.g. accept()).")
 743
 744 # Check for zlib.  If the check passes, libz will be automatically
 745 # added to the LIBS environment variable.
 746 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 747     error('Did not find needed zlib compression library '
 748           'and/or zlib.h header file.\n'
 749           'Please install zlib and try again.')
 750
 751 # If we have the protobuf compiler, also make sure we have the
 752 # development libraries. If the check passes, libprotobuf will be
 753 # automatically added to the LIBS environment variable. After
 754 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 755 # got both protoc and libprotobuf available.
 756 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 757     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 758                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 759
 760 # Valgrind gets much less confused if you tell it when you're using
 761 # alternative stacks.
 762 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 763
 764 # If we have the compiler but not the library, print another warning.
 765 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 766     warning('Did not find protocol buffer library and/or headers.\n'
 767             'Please install libprotobuf-dev for tracing support.')
 768
 769 # Check for librt.
 770 have_posix_clock = \
 771     conf.CheckLibWithHeader(None, 'time.h', 'C',
 772                             'clock_nanosleep(0,0,NULL,NULL);') or \
 773     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 774                             'clock_nanosleep(0,0,NULL,NULL);')
 775
 776 have_posix_timers = \
 777     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 778                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 779
 780 if not GetOption('without_tcmalloc'):
 781     if conf.CheckLib('tcmalloc'):
 782         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 783     elif conf.CheckLib('tcmalloc_minimal'):
 784         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 785     else:
 786         warning("You can get a 12% performance improvement by "
 787                 "installing tcmalloc (libgoogle-perftools-dev package "
 788                 "on Ubuntu or RedHat).")
 789
 790
 791 # Detect back trace implementations. The last implementation in the
 792 # list will be used by default.
 793 backtrace_impls = [ "none" ]
 794
 795 backtrace_checker = 'char temp;' + \
 796     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 797 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 798     backtrace_impls.append("glibc")
 799 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 800                              backtrace_checker):
 801     # NetBSD and FreeBSD need libexecinfo.
 802     backtrace_impls.append("glibc")
 803     main.Append(LIBS=['execinfo'])
 804
 805 if backtrace_impls[-1] == "none":
 806     default_backtrace_impl = "none"
 807     warning("No suitable back trace implementation found.")
 808
 809 if not have_posix_clock:
 810     warning("Can't find library for POSIX clocks.")
 811
 812 # Check for <fenv.h> (C99 FP environment control)
 813 have_fenv = conf.CheckHeader('fenv.h', '<>')
 814 if not have_fenv:
 815     warning("Header file <fenv.h> not found.\n"
 816             "This host has no IEEE FP rounding mode control.")
 817
 818 # Check for <png.h> (libpng library needed if wanting to dump
 819 # frame buffer image in png format)
 820 have_png = conf.CheckHeader('png.h', '<>')
 821 if not have_png:
 822     warning("Header file <png.h> not found.\n"
 823             "This host has no libpng library.\n"
 824             "Disabling support for PNG framebuffers.")
 825
 826 # Check if we should enable KVM-based hardware virtualization. The API
 827 # we rely on exists since version 2.6.36 of the kernel, but somehow
 828 # the KVM_API_VERSION does not reflect the change. We test for one of
 829 # the types as a fall back.
 830 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 831 if not have_kvm:
 832     print("Info: Compatible header file <linux/kvm.h> not found, "
 833           "disabling KVM support.")
 834
 835 # Check if the TUN/TAP driver is available.
 836 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 837 if not have_tuntap:
 838     print("Info: Compatible header file <linux/if_tun.h> not found.")
 839
 840 # x86 needs support for xsave. We test for the structure here since we
 841 # won't be able to run new tests by the time we know which ISA we're
 842 # targeting.
 843 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 844                                     '#include <linux/kvm.h>') != 0
 845
 846 # Check if the requested target ISA is compatible with the host
 847 def is_isa_kvm_compatible(isa):
 848     try:
 849         import platform
 850         host_isa = platform.machine()
 851     except:
 852         warning("Failed to determine host ISA.")
 853         return False
 854
 855     if not have_posix_timers:
 856         warning("Can not enable KVM, host seems to lack support "
 857                 "for POSIX timers")
 858         return False
 859
 860     if isa == "arm":
 861         return host_isa in ( "armv7l", "aarch64" )
 862     elif isa == "x86":
 863         if host_isa != "x86_64":
 864             return False
 865
 866         if not have_kvm_xsave:
 867             warning("KVM on x86 requires xsave support in kernel headers.")
 868             return False
 869
 870         return True
 871     else:
 872         return False
 873
 874
 875 # Check if the exclude_host attribute is available. We want this to
 876 # get accurate instruction counts in KVM.
 877 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 878     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 879
 880 def check_hdf5():
 881     return \
 882         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 883                                 'H5Fcreate("", 0, 0, 0);') and \
 884         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 885                                 'H5::H5File("", 0);')
 886
 887 def check_hdf5_pkg(name):
 888     print("Checking for %s using pkg-config..." % name, end="")
 889     if not have_pkg_config:
 890         print(" pkg-config not found")
 891         return False
 892
 893     try:
 894         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 895         print(" yes")
 896         return True
 897     except:
 898         print(" no")
 899         return False
 900
 901 # Check if there is a pkg-config configuration for hdf5. If we find
 902 # it, setup the environment to enable linking and header inclusion. We
 903 # don't actually try to include any headers or link with hdf5 at this
 904 # stage.
 905 if not check_hdf5_pkg('hdf5-serial'):
 906     check_hdf5_pkg('hdf5')
 907
 908 # Check if the HDF5 libraries can be found. This check respects the
 909 # include path and library path provided by pkg-config. We perform
 910 # this check even if there isn't a pkg-config configuration for hdf5
 911 # since some installations don't use pkg-config.
 912 have_hdf5 = check_hdf5()
 913 if not have_hdf5:
 914     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 915     print("         HDF5 support.")
 916
 917 ######################################################################
 918 #
 919 # Finish the configuration
 920 #
 921 main = conf.Finish()
 922
 923 ######################################################################
 924 #
 925 # Collect all non-global variables
 926 #
 927
 928 # Define the universe of supported ISAs
 929 all_isa_list = [ ]
 930 all_gpu_isa_list = [ ]
 931 Export('all_isa_list')
 932 Export('all_gpu_isa_list')
 933
 934 class CpuModel(object):
 935     '''The CpuModel class encapsulates everything the ISA parser needs to
 936     know about a particular CPU model.'''
 937
 938     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 939     dict = {}
 940
 941     # Constructor.  Automatically adds models to CpuModel.dict.
 942     def __init__(self, name, default=False):
 943         self.name = name           # name of model
 944
 945         # This cpu is enabled by default
 946         self.default = default
 947
 948         # Add self to dict
 949         if name in CpuModel.dict:
 950             raise AttributeError("CpuModel '%s' already registered" % name)
 951         CpuModel.dict[name] = self
 952
 953 Export('CpuModel')
 954
 955 # Sticky variables get saved in the variables file so they persist from
 956 # one invocation to the next (unless overridden, in which case the new
 957 # value becomes sticky).
 958 sticky_vars = Variables(args=ARGUMENTS)
 959 Export('sticky_vars')
 960
 961 # Sticky variables that should be exported
 962 export_vars = []
 963 Export('export_vars')
 964
 965 # For Ruby
 966 all_protocols = []
 967 Export('all_protocols')
 968 protocol_dirs = []
 969 Export('protocol_dirs')
 970 slicc_includes = []
 971 Export('slicc_includes')
 972
 973 # Walk the tree and execute all SConsopts scripts that wil add to the
 974 # above variables
 975 if GetOption('verbose'):
 976     print("Reading SConsopts")
 977 for bdir in [ base_dir ] + extras_dir_list:
 978     if not isdir(bdir):
 979         error("Directory '%s' does not exist." % bdir)
 980     for root, dirs, files in os.walk(bdir):
 981         if 'SConsopts' in files:
 982             if GetOption('verbose'):
 983                 print("Reading", joinpath(root, 'SConsopts'))
 984             SConscript(joinpath(root, 'SConsopts'))
 985
 986 all_isa_list.sort()
 987 all_gpu_isa_list.sort()
 988
 989 sticky_vars.AddVariables(
 990     EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list),
 991     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'gcn3', all_gpu_isa_list),
 992     ListVariable('CPU_MODELS', 'CPU models',
 993                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 994                  sorted(CpuModel.dict.keys())),
 995     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 996                  False),
 997     BoolVariable('USE_SSE2',
 998                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 999                  False),
1000     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1001     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1002     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
1003     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1004                  have_kvm),
1005     BoolVariable('USE_TUNTAP',
1006                  'Enable using a tap device to bridge to the host network',
1007                  have_tuntap),
1008     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1009     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1010                   all_protocols),
1011     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1012                  backtrace_impls[-1], backtrace_impls),
1013     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1014                  64),
1015     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
1016     )
1017
1018 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1019 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA',
1020                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
1021                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1022                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1023                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1024
1025 ###################################################
1026 #
1027 # Define a SCons builder for configuration flag headers.
1028 #
1029 ###################################################
1030
1031 # This function generates a config header file that #defines the
1032 # variable symbol to the current variable setting (0 or 1).  The source
1033 # operands are the name of the variable and a Value node containing the
1034 # value of the variable.
1035 def build_config_file(target, source, env):
1036     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
1037     with open(str(target[0]), 'w') as f:
1038         print('#define', variable, value, file=f)
1039     return None
1040
1041 # Combine the two functions into a scons Action object.
1042 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1043
1044 # The emitter munges the source & target node lists to reflect what
1045 # we're really doing.
1046 def config_emitter(target, source, env):
1047     # extract variable name from Builder arg
1048     variable = str(target[0])
1049     # True target is config header file
1050     target = joinpath('config', variable.lower() + '.hh')
1051     val = env[variable]
1052     if isinstance(val, bool):
1053         # Force value to 0/1
1054         val = int(val)
1055     elif isinstance(val, str):
1056         val = '"' + val + '"'
1057
1058     # Sources are variable name & value (packaged in SCons Value nodes)
1059     return ([target], [Value(variable), Value(val)])
1060
1061 config_builder = Builder(emitter = config_emitter, action = config_action)
1062
1063 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1064
1065 ###################################################
1066 #
1067 # Builders for static and shared partially linked object files.
1068 #
1069 ###################################################
1070
1071 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1072                                  src_suffix='$OBJSUFFIX',
1073                                  src_builder=['StaticObject', 'Object'],
1074                                  LINKFLAGS='$PLINKFLAGS',
1075                                  LIBS='')
1076
1077 def partial_shared_emitter(target, source, env):
1078     for tgt in target:
1079         tgt.attributes.shared = 1
1080     return (target, source)
1081 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1082                                  emitter=partial_shared_emitter,
1083                                  src_suffix='$SHOBJSUFFIX',
1084                                  src_builder='SharedObject',
1085                                  SHLINKFLAGS='$PSHLINKFLAGS',
1086                                  LIBS='')
1087
1088 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1089                          'PartialStatic' : partial_static_builder })
1090
1091 def add_local_rpath(env, *targets):
1092     '''Set up an RPATH for a library which lives in the build directory.
1093
1094     The construction environment variable BIN_RPATH_PREFIX should be set to
1095     the relative path of the build directory starting from the location of the
1096     binary.'''
1097     for target in targets:
1098         target = env.Entry(target)
1099         if not isinstance(target, SCons.Node.FS.Dir):
1100             target = target.dir
1101         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1102         components = [
1103             '\\$$ORIGIN',
1104             '${BIN_RPATH_PREFIX}',
1105             relpath
1106         ]
1107         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1108
1109 if sys.platform != "darwin":
1110     main.Append(LINKFLAGS=Split('-z origin'))
1111
1112 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1113
1114 # builds in ext are shared across all configs in the build root.
1115 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1116 ext_build_dirs = []
1117 for root, dirs, files in os.walk(ext_dir):
1118     if 'SConscript' in files:
1119         build_dir = os.path.relpath(root, ext_dir)
1120         ext_build_dirs.append(build_dir)
1121         main.SConscript(joinpath(root, 'SConscript'),
1122                         variant_dir=joinpath(build_root, build_dir))
1123
1124 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1125 Export('gdb_xml_dir')
1126
1127 ###################################################
1128 #
1129 # This builder and wrapper method are used to set up a directory with
1130 # switching headers. Those are headers which are in a generic location and
1131 # that include more specific headers from a directory chosen at build time
1132 # based on the current build settings.
1133 #
1134 ###################################################
1135
1136 def build_switching_header(target, source, env):
1137     path = str(target[0])
1138     subdir = str(source[0])
1139     dp, fp = os.path.split(path)
1140     dp = os.path.relpath(os.path.realpath(dp),
1141                          os.path.realpath(env['BUILDDIR']))
1142     with open(path, 'w') as hdr:
1143         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1144
1145 switching_header_action = MakeAction(build_switching_header,
1146                                      Transform('GENERATE'))
1147
1148 switching_header_builder = Builder(action=switching_header_action,
1149                                    source_factory=Value,
1150                                    single_source=True)
1151
1152 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1153
1154 def switching_headers(self, headers, source):
1155     for header in headers:
1156         self.SwitchingHeader(header, source)
1157
1158 main.AddMethod(switching_headers, 'SwitchingHeaders')
1159
1160 ###################################################
1161 #
1162 # Define build environments for selected configurations.
1163 #
1164 ###################################################
1165
1166 for variant_path in variant_paths:
1167     if not GetOption('silent'):
1168         print("Building in", variant_path)
1169
1170     # Make a copy of the build-root environment to use for this config.
1171     env = main.Clone()
1172     env['BUILDDIR'] = variant_path
1173
1174     # variant_dir is the tail component of build path, and is used to
1175     # determine the build parameters (e.g., 'X86')
1176     (build_root, variant_dir) = splitpath(variant_path)
1177
1178     # Set env variables according to the build directory config.
1179     sticky_vars.files = []
1180     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1181     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1182     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1183     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1184     if isfile(current_vars_file):
1185         sticky_vars.files.append(current_vars_file)
1186         if not GetOption('silent'):
1187             print("Using saved variables file %s" % current_vars_file)
1188     elif variant_dir in ext_build_dirs:
1189         # Things in ext are built without a variant directory.
1190         continue
1191     else:
1192         # Build dir-specific variables file doesn't exist.
1193
1194         # Make sure the directory is there so we can create it later
1195         opt_dir = dirname(current_vars_file)
1196         if not isdir(opt_dir):
1197             mkdir(opt_dir)
1198
1199         # Get default build variables from source tree.  Variables are
1200         # normally determined by name of $VARIANT_DIR, but can be
1201         # overridden by '--default=' arg on command line.
1202         default = GetOption('default')
1203         opts_dir = joinpath(main.root.abspath, 'build_opts')
1204         if default:
1205             default_vars_files = [joinpath(build_root, 'variables', default),
1206                                   joinpath(opts_dir, default)]
1207         else:
1208             default_vars_files = [joinpath(opts_dir, variant_dir)]
1209         existing_files = list(filter(isfile, default_vars_files))
1210         if existing_files:
1211             default_vars_file = existing_files[0]
1212             sticky_vars.files.append(default_vars_file)
1213             print("Variables file %s not found,\n  using defaults in %s"
1214                   % (current_vars_file, default_vars_file))
1215         else:
1216             error("Cannot find variables file %s or default file(s) %s"
1217                   % (current_vars_file, ' or '.join(default_vars_files)))
1218             Exit(1)
1219
1220     # Apply current variable settings to env
1221     sticky_vars.Update(env)
1222
1223     help_texts["local_vars"] += \
1224         "Build variables for %s:\n" % variant_dir \
1225                  + sticky_vars.GenerateHelpText(env)
1226
1227     # Process variable settings.
1228
1229     if not have_fenv and env['USE_FENV']:
1230         warning("<fenv.h> not available; forcing USE_FENV to False in",
1231                 variant_dir + ".")
1232         env['USE_FENV'] = False
1233
1234     if not env['USE_FENV']:
1235         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1236                 "FP results may deviate slightly from other platforms.")
1237
1238     if not have_png and env['USE_PNG']:
1239         warning("<png.h> not available; forcing USE_PNG to False in",
1240                 variant_dir + ".")
1241         env['USE_PNG'] = False
1242
1243     if env['USE_PNG']:
1244         env.Append(LIBS=['png'])
1245
1246     if env['EFENCE']:
1247         env.Append(LIBS=['efence'])
1248
1249     if env['USE_KVM']:
1250         if not have_kvm:
1251             warning("Can not enable KVM, host seems to lack KVM support")
1252             env['USE_KVM'] = False
1253         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1254             print("Info: KVM support disabled due to unsupported host and "
1255                   "target ISA combination")
1256             env['USE_KVM'] = False
1257
1258     if env['USE_TUNTAP']:
1259         if not have_tuntap:
1260             warning("Can't connect EtherTap with a tap device.")
1261             env['USE_TUNTAP'] = False
1262
1263     if env['BUILD_GPU']:
1264         env.Append(CPPDEFINES=['BUILD_GPU'])
1265
1266     # Warn about missing optional functionality
1267     if env['USE_KVM']:
1268         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1269             warning("perf_event headers lack support for the exclude_host "
1270                     "attribute. KVM instruction counts will be inaccurate.")
1271
1272     # Save sticky variable settings back to current variables file
1273     sticky_vars.Save(current_vars_file, env)
1274
1275     if env['USE_SSE2']:
1276         env.Append(CCFLAGS=['-msse2'])
1277
1278     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1279     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1280
1281     # The src/SConscript file sets up the build rules in 'env' according
1282     # to the configured variables.  It returns a list of environments,
1283     # one for each variant build (debug, opt, etc.)
1284     SConscript('src/SConscript', variant_dir=variant_path,
1285                exports=['env', 'marshal_env'])
1286
1287 # base help text
1288 Help('''
1289 Usage: scons [scons options] [build variables] [target(s)]
1290
1291 Extra scons options:
1292 %(options)s
1293
1294 Global build variables:
1295 %(global_vars)s
1296
1297 %(local_vars)s
1298 ''' % help_texts)
1299
1300 atexit.register(summarize_warnings)