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