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     if compareVersions(clang_version, "10.0") >= 0:
 480         main.Append(CCFLAGS=['-Wno-c99-designator'])
 481
 482     if compareVersions(clang_version, "8.0") >= 0:
 483         main.Append(CCFLAGS=['-Wno-defaulted-function-deleted'])
 484
 485     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 486
 487     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 488     # opposed to libstdc++, as the later is dated.
 489     if sys.platform == "darwin":
 490         main.Append(CXXFLAGS=['-stdlib=libc++'])
 491         main.Append(LIBS=['c++'])
 492
 493     # On FreeBSD we need libthr.
 494     if sys.platform.startswith('freebsd'):
 495         main.Append(LIBS=['thr'])
 496
 497 # Add sanitizers flags
 498 sanitizers=[]
 499 if GetOption('with_ubsan'):
 500     # Only gcc >= 4.9 supports UBSan, so check both the version
 501     # and the command-line option before adding the compiler and
 502     # linker flags.
 503     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 504         sanitizers.append('undefined')
 505 if GetOption('with_asan'):
 506     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 507     # by the build system
 508     sanitizers.append('address')
 509     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 510     suppressions_opt = 'suppressions=%s' % suppressions_file
 511     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 512                                             'print_suppressions=0'])
 513     print()
 514     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 515             'environment variable to "%s" when running gem5' %
 516             suppressions_opt)
 517     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 518     print()
 519 if sanitizers:
 520     sanitizers = ','.join(sanitizers)
 521     if main['GCC'] or main['CLANG']:
 522         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 523                              '-fno-omit-frame-pointer'],
 524                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 525     else:
 526         warning("Don't know how to enable %s sanitizer(s) for your "
 527                 "compiler." % sanitizers)
 528
 529 # Set up common yacc/bison flags (needed for Ruby)
 530 main['YACCFLAGS'] = '-d'
 531 main['YACCHXXFILESUFFIX'] = '.hh'
 532
 533 # Do this after we save setting back, or else we'll tack on an
 534 # extra 'qdo' every time we run scons.
 535 if main['BATCH']:
 536     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 537     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 538     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 539     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 540     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 541
 542 if sys.platform == 'cygwin':
 543     # cygwin has some header file issues...
 544     main.Append(CCFLAGS=["-Wno-uninitialized"])
 545
 546
 547 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 548
 549 # Check for the protobuf compiler
 550 try:
 551     main['HAVE_PROTOC'] = True
 552     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 553
 554     # First two words should be "libprotoc x.y.z"
 555     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 556         warning('Protocol buffer compiler (protoc) not found.\n'
 557                 'Please install protobuf-compiler for tracing support.')
 558         main['HAVE_PROTOC'] = False
 559     else:
 560         # Based on the availability of the compress stream wrappers,
 561         # require 2.1.0
 562         min_protoc_version = '2.1.0'
 563         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 564             warning('protoc version', min_protoc_version,
 565                     'or newer required.\n'
 566                     'Installed version:', protoc_version[1])
 567             main['HAVE_PROTOC'] = False
 568         else:
 569             # Attempt to determine the appropriate include path and
 570             # library path using pkg-config, that means we also need to
 571             # check for pkg-config. Note that it is possible to use
 572             # protobuf without the involvement of pkg-config. Later on we
 573             # check go a library config check and at that point the test
 574             # will fail if libprotobuf cannot be found.
 575             if have_pkg_config:
 576                 try:
 577                     # Attempt to establish what linking flags to add for
 578                     # protobuf
 579                     # using pkg-config
 580                     main.ParseConfig(
 581                             'pkg-config --cflags --libs-only-L protobuf')
 582                 except:
 583                     warning('pkg-config could not get protobuf flags.')
 584 except Exception as e:
 585     warning('While checking protoc version:', str(e))
 586     main['HAVE_PROTOC'] = False
 587
 588 # Check for 'timeout' from GNU coreutils. If present, regressions will
 589 # be run with a time limit. We require version 8.13 since we rely on
 590 # support for the '--foreground' option.
 591 if sys.platform.startswith('freebsd'):
 592     timeout_lines = readCommand(['gtimeout', '--version'],
 593                                 exception='').splitlines()
 594 else:
 595     timeout_lines = readCommand(['timeout', '--version'],
 596                                 exception='').splitlines()
 597 # Get the first line and tokenize it
 598 timeout_version = timeout_lines[0].split() if timeout_lines else []
 599 main['TIMEOUT'] =  timeout_version and \
 600     compareVersions(timeout_version[-1], '8.13') >= 0
 601
 602 # Add a custom Check function to test for structure members.
 603 def CheckMember(context, include, decl, member, include_quotes="<>"):
 604     context.Message("Checking for member %s in %s..." %
 605                     (member, decl))
 606     text = """
 607 #include %(header)s
 608 int main(){
 609   %(decl)s test;
 610   (void)test.%(member)s;
 611   return 0;
 612 };
 613 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 614         "decl" : decl,
 615         "member" : member,
 616         }
 617
 618     ret = context.TryCompile(text, extension=".cc")
 619     context.Result(ret)
 620     return ret
 621
 622 # Platform-specific configuration.  Note again that we assume that all
 623 # builds under a given build root run on the same host platform.
 624 conf = Configure(main,
 625                  conf_dir = joinpath(build_root, '.scons_config'),
 626                  log_file = joinpath(build_root, 'scons_config.log'),
 627                  custom_tests = {
 628         'CheckMember' : CheckMember,
 629         })
 630
 631 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 632 try:
 633     import platform
 634     uname = platform.uname()
 635     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 636         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 637             main.Append(CCFLAGS=['-arch', 'x86_64'])
 638             main.Append(CFLAGS=['-arch', 'x86_64'])
 639             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 640             main.Append(ASFLAGS=['-arch', 'x86_64'])
 641 except:
 642     pass
 643
 644 # Recent versions of scons substitute a "Null" object for Configure()
 645 # when configuration isn't necessary, e.g., if the "--help" option is
 646 # present.  Unfortuantely this Null object always returns false,
 647 # breaking all our configuration checks.  We replace it with our own
 648 # more optimistic null object that returns True instead.
 649 if not conf:
 650     def NullCheck(*args, **kwargs):
 651         return True
 652
 653     class NullConf:
 654         def __init__(self, env):
 655             self.env = env
 656         def Finish(self):
 657             return self.env
 658         def __getattr__(self, mname):
 659             return NullCheck
 660
 661     conf = NullConf(main)
 662
 663 # Cache build files in the supplied directory.
 664 if main['M5_BUILD_CACHE']:
 665     print('Using build cache located at', main['M5_BUILD_CACHE'])
 666     CacheDir(main['M5_BUILD_CACHE'])
 667
 668 main['USE_PYTHON'] = not GetOption('without_python')
 669 if main['USE_PYTHON']:
 670     # Find Python include and library directories for embedding the
 671     # interpreter. We rely on python-config to resolve the appropriate
 672     # includes and linker flags. ParseConfig does not seem to understand
 673     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 674     # we add them explicitly below. If you want to link in an alternate
 675     # version of python, see above for instructions on how to invoke
 676     # scons with the appropriate PATH set.
 677
 678     python_config = main.Detect(main['PYTHON_CONFIG'])
 679     if python_config is None:
 680         error("Can't find a suitable python-config, tried %s" % \
 681               main['PYTHON_CONFIG'])
 682
 683     print("Info: Using Python config: %s" % (python_config, ))
 684     py_includes = readCommand([python_config, '--includes'],
 685                               exception='').split()
 686     py_includes = list(filter(
 687         lambda s: match(r'.*\/include\/.*',s), py_includes))
 688     # Strip the -I from the include folders before adding them to the
 689     # CPPPATH
 690     py_includes = list(map(
 691         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 692     main.Append(CPPPATH=py_includes)
 693
 694     # Read the linker flags and split them into libraries and other link
 695     # flags. The libraries are added later through the call the CheckLib.
 696     # Note: starting in Python 3.8 the --embed flag is required to get the
 697     # -lpython3.8 linker flag
 698     retcode, cmd_stdout = readCommandWithReturn(
 699         [python_config, '--ldflags', '--embed'], exception='')
 700     if retcode != 0:
 701         # If --embed isn't detected then we're running python <3.8
 702         retcode, cmd_stdout = readCommandWithReturn(
 703             [python_config, '--ldflags'], exception='')
 704
 705     # Checking retcode again
 706     if retcode != 0:
 707         error("Failing on python-config --ldflags command")
 708
 709     py_ld_flags = cmd_stdout.split()
 710
 711     py_libs = []
 712     for lib in py_ld_flags:
 713          if not lib.startswith('-l'):
 714              main.Append(LINKFLAGS=[lib])
 715          else:
 716              lib = lib[2:]
 717              if lib not in py_libs:
 718                  py_libs.append(lib)
 719
 720     # verify that this stuff works
 721     if not conf.CheckHeader('Python.h', '<>'):
 722         error("Check failed for Python.h header in",
 723                 ' '.join(py_includes), "\n"
 724               "Two possible reasons:\n"
 725               "1. Python headers are not installed (You can install the "
 726               "package python-dev on Ubuntu and RedHat)\n"
 727               "2. SCons is using a wrong C compiler. This can happen if "
 728               "CC has the wrong value.\n"
 729               "CC = %s" % main['CC'])
 730
 731     for lib in py_libs:
 732         if not conf.CheckLib(lib):
 733             error("Can't find library %s required by python." % lib)
 734
 735 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
 736 # Bare minimum environment that only includes python
 737 base_py_env = main.Clone()
 738
 739 # On Solaris you need to use libsocket for socket ops
 740 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 741    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 742                                   'C++', 'accept(0,0,0);'):
 743        error("Can't find library with socket calls (e.g. accept()).")
 744
 745 # Check for zlib.  If the check passes, libz will be automatically
 746 # added to the LIBS environment variable.
 747 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 748     error('Did not find needed zlib compression library '
 749           'and/or zlib.h header file.\n'
 750           'Please install zlib and try again.')
 751
 752 # If we have the protobuf compiler, also make sure we have the
 753 # development libraries. If the check passes, libprotobuf will be
 754 # automatically added to the LIBS environment variable. After
 755 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 756 # got both protoc and libprotobuf available.
 757 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 758     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 759                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 760
 761 # Valgrind gets much less confused if you tell it when you're using
 762 # alternative stacks.
 763 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 764
 765 # If we have the compiler but not the library, print another warning.
 766 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 767     warning('Did not find protocol buffer library and/or headers.\n'
 768             'Please install libprotobuf-dev for tracing support.')
 769
 770 # Check for librt.
 771 have_posix_clock = \
 772     conf.CheckLibWithHeader(None, 'time.h', 'C',
 773                             'clock_nanosleep(0,0,NULL,NULL);') or \
 774     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 775                             'clock_nanosleep(0,0,NULL,NULL);')
 776
 777 have_posix_timers = \
 778     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 779                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 780
 781 if not GetOption('without_tcmalloc'):
 782     if conf.CheckLib('tcmalloc'):
 783         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 784     elif conf.CheckLib('tcmalloc_minimal'):
 785         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 786     else:
 787         warning("You can get a 12% performance improvement by "
 788                 "installing tcmalloc (libgoogle-perftools-dev package "
 789                 "on Ubuntu or RedHat).")
 790
 791
 792 # Detect back trace implementations. The last implementation in the
 793 # list will be used by default.
 794 backtrace_impls = [ "none" ]
 795
 796 backtrace_checker = 'char temp;' + \
 797     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 798 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 799     backtrace_impls.append("glibc")
 800 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 801                              backtrace_checker):
 802     # NetBSD and FreeBSD need libexecinfo.
 803     backtrace_impls.append("glibc")
 804     main.Append(LIBS=['execinfo'])
 805
 806 if backtrace_impls[-1] == "none":
 807     default_backtrace_impl = "none"
 808     warning("No suitable back trace implementation found.")
 809
 810 if not have_posix_clock:
 811     warning("Can't find library for POSIX clocks.")
 812
 813 # Check for <fenv.h> (C99 FP environment control)
 814 have_fenv = conf.CheckHeader('fenv.h', '<>')
 815 if not have_fenv:
 816     warning("Header file <fenv.h> not found.\n"
 817             "This host has no IEEE FP rounding mode control.")
 818
 819 # Check for <png.h> (libpng library needed if wanting to dump
 820 # frame buffer image in png format)
 821 have_png = conf.CheckHeader('png.h', '<>')
 822 if not have_png:
 823     warning("Header file <png.h> not found.\n"
 824             "This host has no libpng library.\n"
 825             "Disabling support for PNG framebuffers.")
 826
 827 # Check if we should enable KVM-based hardware virtualization. The API
 828 # we rely on exists since version 2.6.36 of the kernel, but somehow
 829 # the KVM_API_VERSION does not reflect the change. We test for one of
 830 # the types as a fall back.
 831 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 832 if not have_kvm:
 833     print("Info: Compatible header file <linux/kvm.h> not found, "
 834           "disabling KVM support.")
 835
 836 # Check if the TUN/TAP driver is available.
 837 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 838 if not have_tuntap:
 839     print("Info: Compatible header file <linux/if_tun.h> not found.")
 840
 841 # x86 needs support for xsave. We test for the structure here since we
 842 # won't be able to run new tests by the time we know which ISA we're
 843 # targeting.
 844 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 845                                     '#include <linux/kvm.h>') != 0
 846
 847 # Check if the requested target ISA is compatible with the host
 848 def is_isa_kvm_compatible(isa):
 849     try:
 850         import platform
 851         host_isa = platform.machine()
 852     except:
 853         warning("Failed to determine host ISA.")
 854         return False
 855
 856     if not have_posix_timers:
 857         warning("Can not enable KVM, host seems to lack support "
 858                 "for POSIX timers")
 859         return False
 860
 861     if isa == "arm":
 862         return host_isa in ( "armv7l", "aarch64" )
 863     elif isa == "x86":
 864         if host_isa != "x86_64":
 865             return False
 866
 867         if not have_kvm_xsave:
 868             warning("KVM on x86 requires xsave support in kernel headers.")
 869             return False
 870
 871         return True
 872     else:
 873         return False
 874
 875
 876 # Check if the exclude_host attribute is available. We want this to
 877 # get accurate instruction counts in KVM.
 878 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 879     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 880
 881 def check_hdf5():
 882     return \
 883         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 884                                 'H5Fcreate("", 0, 0, 0);') and \
 885         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 886                                 'H5::H5File("", 0);')
 887
 888 def check_hdf5_pkg(name):
 889     print("Checking for %s using pkg-config..." % name, end="")
 890     if not have_pkg_config:
 891         print(" pkg-config not found")
 892         return False
 893
 894     try:
 895         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 896         print(" yes")
 897         return True
 898     except:
 899         print(" no")
 900         return False
 901
 902 # Check if there is a pkg-config configuration for hdf5. If we find
 903 # it, setup the environment to enable linking and header inclusion. We
 904 # don't actually try to include any headers or link with hdf5 at this
 905 # stage.
 906 if not check_hdf5_pkg('hdf5-serial'):
 907     check_hdf5_pkg('hdf5')
 908
 909 # Check if the HDF5 libraries can be found. This check respects the
 910 # include path and library path provided by pkg-config. We perform
 911 # this check even if there isn't a pkg-config configuration for hdf5
 912 # since some installations don't use pkg-config.
 913 have_hdf5 = check_hdf5()
 914 if not have_hdf5:
 915     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 916     print("         HDF5 support.")
 917
 918 ######################################################################
 919 #
 920 # Finish the configuration
 921 #
 922 main = conf.Finish()
 923
 924 ######################################################################
 925 #
 926 # Collect all non-global variables
 927 #
 928
 929 # Define the universe of supported ISAs
 930 all_isa_list = [ ]
 931 all_gpu_isa_list = [ ]
 932 Export('all_isa_list')
 933 Export('all_gpu_isa_list')
 934
 935 class CpuModel(object):
 936     '''The CpuModel class encapsulates everything the ISA parser needs to
 937     know about a particular CPU model.'''
 938
 939     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 940     dict = {}
 941
 942     # Constructor.  Automatically adds models to CpuModel.dict.
 943     def __init__(self, name, default=False):
 944         self.name = name           # name of model
 945
 946         # This cpu is enabled by default
 947         self.default = default
 948
 949         # Add self to dict
 950         if name in CpuModel.dict:
 951             raise AttributeError("CpuModel '%s' already registered" % name)
 952         CpuModel.dict[name] = self
 953
 954 Export('CpuModel')
 955
 956 # Sticky variables get saved in the variables file so they persist from
 957 # one invocation to the next (unless overridden, in which case the new
 958 # value becomes sticky).
 959 sticky_vars = Variables(args=ARGUMENTS)
 960 Export('sticky_vars')
 961
 962 # Sticky variables that should be exported
 963 export_vars = []
 964 Export('export_vars')
 965
 966 # For Ruby
 967 all_protocols = []
 968 Export('all_protocols')
 969 protocol_dirs = []
 970 Export('protocol_dirs')
 971 slicc_includes = []
 972 Export('slicc_includes')
 973
 974 # Walk the tree and execute all SConsopts scripts that wil add to the
 975 # above variables
 976 if GetOption('verbose'):
 977     print("Reading SConsopts")
 978 for bdir in [ base_dir ] + extras_dir_list:
 979     if not isdir(bdir):
 980         error("Directory '%s' does not exist." % bdir)
 981     for root, dirs, files in os.walk(bdir):
 982         if 'SConsopts' in files:
 983             if GetOption('verbose'):
 984                 print("Reading", joinpath(root, 'SConsopts'))
 985             SConscript(joinpath(root, 'SConsopts'))
 986
 987 all_isa_list.sort()
 988 all_gpu_isa_list.sort()
 989
 990 sticky_vars.AddVariables(
 991     EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list),
 992     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 993     ListVariable('CPU_MODELS', 'CPU models',
 994                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 995                  sorted(CpuModel.dict.keys())),
 996     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 997                  False),
 998     BoolVariable('USE_SSE2',
 999                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1000                  False),
1001     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1002     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1003     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
1004     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
1005                  False),
1006     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1007                  have_kvm),
1008     BoolVariable('USE_TUNTAP',
1009                  'Enable using a tap device to bridge to the host network',
1010                  have_tuntap),
1011     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1012     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1013                   all_protocols),
1014     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1015                  backtrace_impls[-1], backtrace_impls),
1016     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1017                  64),
1018     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
1019     )
1020
1021 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1022 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
1023                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
1024                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1025                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1026                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1027
1028 ###################################################
1029 #
1030 # Define a SCons builder for configuration flag headers.
1031 #
1032 ###################################################
1033
1034 # This function generates a config header file that #defines the
1035 # variable symbol to the current variable setting (0 or 1).  The source
1036 # operands are the name of the variable and a Value node containing the
1037 # value of the variable.
1038 def build_config_file(target, source, env):
1039     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
1040     with open(str(target[0]), 'w') as f:
1041         print('#define', variable, value, file=f)
1042     return None
1043
1044 # Combine the two functions into a scons Action object.
1045 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1046
1047 # The emitter munges the source & target node lists to reflect what
1048 # we're really doing.
1049 def config_emitter(target, source, env):
1050     # extract variable name from Builder arg
1051     variable = str(target[0])
1052     # True target is config header file
1053     target = joinpath('config', variable.lower() + '.hh')
1054     val = env[variable]
1055     if isinstance(val, bool):
1056         # Force value to 0/1
1057         val = int(val)
1058     elif isinstance(val, str):
1059         val = '"' + val + '"'
1060
1061     # Sources are variable name & value (packaged in SCons Value nodes)
1062     return ([target], [Value(variable), Value(val)])
1063
1064 config_builder = Builder(emitter = config_emitter, action = config_action)
1065
1066 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1067
1068 ###################################################
1069 #
1070 # Builders for static and shared partially linked object files.
1071 #
1072 ###################################################
1073
1074 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1075                                  src_suffix='$OBJSUFFIX',
1076                                  src_builder=['StaticObject', 'Object'],
1077                                  LINKFLAGS='$PLINKFLAGS',
1078                                  LIBS='')
1079
1080 def partial_shared_emitter(target, source, env):
1081     for tgt in target:
1082         tgt.attributes.shared = 1
1083     return (target, source)
1084 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1085                                  emitter=partial_shared_emitter,
1086                                  src_suffix='$SHOBJSUFFIX',
1087                                  src_builder='SharedObject',
1088                                  SHLINKFLAGS='$PSHLINKFLAGS',
1089                                  LIBS='')
1090
1091 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1092                          'PartialStatic' : partial_static_builder })
1093
1094 def add_local_rpath(env, *targets):
1095     '''Set up an RPATH for a library which lives in the build directory.
1096
1097     The construction environment variable BIN_RPATH_PREFIX should be set to
1098     the relative path of the build directory starting from the location of the
1099     binary.'''
1100     for target in targets:
1101         target = env.Entry(target)
1102         if not isinstance(target, SCons.Node.FS.Dir):
1103             target = target.dir
1104         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1105         components = [
1106             '\\$$ORIGIN',
1107             '${BIN_RPATH_PREFIX}',
1108             relpath
1109         ]
1110         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1111
1112 if sys.platform != "darwin":
1113     main.Append(LINKFLAGS=Split('-z origin'))
1114
1115 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1116
1117 # builds in ext are shared across all configs in the build root.
1118 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1119 ext_build_dirs = []
1120 for root, dirs, files in os.walk(ext_dir):
1121     if 'SConscript' in files:
1122         build_dir = os.path.relpath(root, ext_dir)
1123         ext_build_dirs.append(build_dir)
1124         main.SConscript(joinpath(root, 'SConscript'),
1125                         variant_dir=joinpath(build_root, build_dir))
1126
1127 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1128 Export('gdb_xml_dir')
1129
1130 ###################################################
1131 #
1132 # This builder and wrapper method are used to set up a directory with
1133 # switching headers. Those are headers which are in a generic location and
1134 # that include more specific headers from a directory chosen at build time
1135 # based on the current build settings.
1136 #
1137 ###################################################
1138
1139 def build_switching_header(target, source, env):
1140     path = str(target[0])
1141     subdir = str(source[0])
1142     dp, fp = os.path.split(path)
1143     dp = os.path.relpath(os.path.realpath(dp),
1144                          os.path.realpath(env['BUILDDIR']))
1145     with open(path, 'w') as hdr:
1146         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1147
1148 switching_header_action = MakeAction(build_switching_header,
1149                                      Transform('GENERATE'))
1150
1151 switching_header_builder = Builder(action=switching_header_action,
1152                                    source_factory=Value,
1153                                    single_source=True)
1154
1155 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1156
1157 def switching_headers(self, headers, source):
1158     for header in headers:
1159         self.SwitchingHeader(header, source)
1160
1161 main.AddMethod(switching_headers, 'SwitchingHeaders')
1162
1163 ###################################################
1164 #
1165 # Define build environments for selected configurations.
1166 #
1167 ###################################################
1168
1169 for variant_path in variant_paths:
1170     if not GetOption('silent'):
1171         print("Building in", variant_path)
1172
1173     # Make a copy of the build-root environment to use for this config.
1174     env = main.Clone()
1175     env['BUILDDIR'] = variant_path
1176
1177     # variant_dir is the tail component of build path, and is used to
1178     # determine the build parameters (e.g., 'X86')
1179     (build_root, variant_dir) = splitpath(variant_path)
1180
1181     # Set env variables according to the build directory config.
1182     sticky_vars.files = []
1183     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1184     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1185     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1186     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1187     if isfile(current_vars_file):
1188         sticky_vars.files.append(current_vars_file)
1189         if not GetOption('silent'):
1190             print("Using saved variables file %s" % current_vars_file)
1191     elif variant_dir in ext_build_dirs:
1192         # Things in ext are built without a variant directory.
1193         continue
1194     else:
1195         # Build dir-specific variables file doesn't exist.
1196
1197         # Make sure the directory is there so we can create it later
1198         opt_dir = dirname(current_vars_file)
1199         if not isdir(opt_dir):
1200             mkdir(opt_dir)
1201
1202         # Get default build variables from source tree.  Variables are
1203         # normally determined by name of $VARIANT_DIR, but can be
1204         # overridden by '--default=' arg on command line.
1205         default = GetOption('default')
1206         opts_dir = joinpath(main.root.abspath, 'build_opts')
1207         if default:
1208             default_vars_files = [joinpath(build_root, 'variables', default),
1209                                   joinpath(opts_dir, default)]
1210         else:
1211             default_vars_files = [joinpath(opts_dir, variant_dir)]
1212         existing_files = list(filter(isfile, default_vars_files))
1213         if existing_files:
1214             default_vars_file = existing_files[0]
1215             sticky_vars.files.append(default_vars_file)
1216             print("Variables file %s not found,\n  using defaults in %s"
1217                   % (current_vars_file, default_vars_file))
1218         else:
1219             error("Cannot find variables file %s or default file(s) %s"
1220                   % (current_vars_file, ' or '.join(default_vars_files)))
1221             Exit(1)
1222
1223     # Apply current variable settings to env
1224     sticky_vars.Update(env)
1225
1226     help_texts["local_vars"] += \
1227         "Build variables for %s:\n" % variant_dir \
1228                  + sticky_vars.GenerateHelpText(env)
1229
1230     # Process variable settings.
1231
1232     if not have_fenv and env['USE_FENV']:
1233         warning("<fenv.h> not available; forcing USE_FENV to False in",
1234                 variant_dir + ".")
1235         env['USE_FENV'] = False
1236
1237     if not env['USE_FENV']:
1238         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1239                 "FP results may deviate slightly from other platforms.")
1240
1241     if not have_png and env['USE_PNG']:
1242         warning("<png.h> not available; forcing USE_PNG to False in",
1243                 variant_dir + ".")
1244         env['USE_PNG'] = False
1245
1246     if env['USE_PNG']:
1247         env.Append(LIBS=['png'])
1248
1249     if env['EFENCE']:
1250         env.Append(LIBS=['efence'])
1251
1252     if env['USE_KVM']:
1253         if not have_kvm:
1254             warning("Can not enable KVM, host seems to lack KVM support")
1255             env['USE_KVM'] = False
1256         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1257             print("Info: KVM support disabled due to unsupported host and "
1258                   "target ISA combination")
1259             env['USE_KVM'] = False
1260
1261     if env['USE_TUNTAP']:
1262         if not have_tuntap:
1263             warning("Can't connect EtherTap with a tap device.")
1264             env['USE_TUNTAP'] = False
1265
1266     if env['BUILD_GPU']:
1267         env.Append(CPPDEFINES=['BUILD_GPU'])
1268
1269     # Warn about missing optional functionality
1270     if env['USE_KVM']:
1271         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1272             warning("perf_event headers lack support for the exclude_host "
1273                     "attribute. KVM instruction counts will be inaccurate.")
1274
1275     # Save sticky variable settings back to current variables file
1276     sticky_vars.Save(current_vars_file, env)
1277
1278     if env['USE_SSE2']:
1279         env.Append(CCFLAGS=['-msse2'])
1280
1281     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1282     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1283
1284     # The src/SConscript file sets up the build rules in 'env' according
1285     # to the configured variables.  It returns a list of environments,
1286     # one for each variant build (debug, opt, etc.)
1287     SConscript('src/SConscript', variant_dir=variant_path,
1288                exports=['env', 'base_py_env'])
1289
1290 # base help text
1291 Help('''
1292 Usage: scons [scons options] [build variables] [target(s)]
1293
1294 Extra scons options:
1295 %(options)s
1296
1297 Global build variables:
1298 %(global_vars)s
1299
1300 %(local_vars)s
1301 ''' % help_texts)
1302
1303 atexit.register(summarize_warnings)