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
 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' ]),
 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 and \
 408        compareVersions(gcc_version, '8.1') < 0:
 409         # Incremental linking with LTO is currently broken in gcc versions
 410         # 4.9 to 8.1.
 411         #
 412         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 413         #
 414         # gcc versions 6.0 and greater accept an -flinker-output flag which
 415         # selects what type of output the linker should generate. This is
 416         # necessary for incremental lto to work, but is also broken in
 417         # versions of gcc up to 8.1.
 418         #
 419         # https://gcc.gnu.org/gcc-6/changes.html
 420         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 421         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 422         main['BROKEN_INCREMENTAL_LTO'] = True
 423
 424     disable_lto = GetOption('no_lto')
 425     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 426             not GetOption('force_lto'):
 427         warning('Your compiler doesn\'t support incremental linking and lto '
 428                 'at the same time, so lto is being disabled. To force lto on '
 429                 'anyway, use the --force-lto option. That will disable '
 430                 'partial linking.')
 431         disable_lto = True
 432
 433     # Add the appropriate Link-Time Optimization (LTO) flags
 434     # unless LTO is explicitly turned off. Note that these flags
 435     # are only used by the fast target.
 436     if not disable_lto:
 437         # Pass the LTO flag when compiling to produce GIMPLE
 438         # output, we merely create the flags here and only append
 439         # them later
 440         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 441
 442         # Use the same amount of jobs for LTO as we are running
 443         # scons with
 444         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 445
 446     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 447                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 448
 449 elif main['CLANG']:
 450     # Check for a supported version of clang, >= 3.1 is needed to
 451     # support similar features as gcc 4.8. See
 452     # http://clang.llvm.org/cxx_status.html for details
 453     clang_version_re = re.compile(".* version (\d+\.\d+)")
 454     clang_version_match = clang_version_re.search(CXX_version)
 455     if (clang_version_match):
 456         clang_version = clang_version_match.groups()[0]
 457         if compareVersions(clang_version, "3.1") < 0:
 458             error('clang version 3.1 or newer required.\n'
 459                   'Installed version:', clang_version)
 460     else:
 461         error('Unable to determine clang version.')
 462
 463     # clang has a few additional warnings that we disable, extraneous
 464     # parantheses are allowed due to Ruby's printing of the AST,
 465     # finally self assignments are allowed as the generated CPU code
 466     # is relying on this
 467     main.Append(CCFLAGS=['-Wno-parentheses',
 468                          '-Wno-self-assign',
 469                          # Some versions of libstdc++ (4.8?) seem to
 470                          # use struct hash and class hash
 471                          # interchangeably.
 472                          '-Wno-mismatched-tags',
 473                          ])
 474
 475     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 476
 477     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 478     # opposed to libstdc++, as the later is dated.
 479     if sys.platform == "darwin":
 480         main.Append(CXXFLAGS=['-stdlib=libc++'])
 481         main.Append(LIBS=['c++'])
 482
 483     # On FreeBSD we need libthr.
 484     if sys.platform.startswith('freebsd'):
 485         main.Append(LIBS=['thr'])
 486
 487 # Add sanitizers flags
 488 sanitizers=[]
 489 if GetOption('with_ubsan'):
 490     # Only gcc >= 4.9 supports UBSan, so check both the version
 491     # and the command-line option before adding the compiler and
 492     # linker flags.
 493     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 494         sanitizers.append('undefined')
 495 if GetOption('with_asan'):
 496     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 497     # by the build system
 498     sanitizers.append('address')
 499     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 500     suppressions_opt = 'suppressions=%s' % suppressions_file
 501     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 502                                             'print_suppressions=0'])
 503     print()
 504     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 505             'environment variable to "%s" when running gem5' %
 506             suppressions_opt)
 507     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 508     print()
 509 if sanitizers:
 510     sanitizers = ','.join(sanitizers)
 511     if main['GCC'] or main['CLANG']:
 512         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 513                              '-fno-omit-frame-pointer'],
 514                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 515     else:
 516         warning("Don't know how to enable %s sanitizer(s) for your "
 517                 "compiler." % sanitizers)
 518
 519 # Set up common yacc/bison flags (needed for Ruby)
 520 main['YACCFLAGS'] = '-d'
 521 main['YACCHXXFILESUFFIX'] = '.hh'
 522
 523 # Do this after we save setting back, or else we'll tack on an
 524 # extra 'qdo' every time we run scons.
 525 if main['BATCH']:
 526     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 527     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 528     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 529     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 530     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 531
 532 if sys.platform == 'cygwin':
 533     # cygwin has some header file issues...
 534     main.Append(CCFLAGS=["-Wno-uninitialized"])
 535
 536
 537 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 538
 539 # Check for the protobuf compiler
 540 try:
 541     main['HAVE_PROTOC'] = True
 542     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 543
 544     # First two words should be "libprotoc x.y.z"
 545     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 546         warning('Protocol buffer compiler (protoc) not found.\n'
 547                 'Please install protobuf-compiler for tracing support.')
 548         main['HAVE_PROTOC'] = False
 549     else:
 550         # Based on the availability of the compress stream wrappers,
 551         # require 2.1.0
 552         min_protoc_version = '2.1.0'
 553         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 554             warning('protoc version', min_protoc_version,
 555                     'or newer required.\n'
 556                     'Installed version:', protoc_version[1])
 557             main['HAVE_PROTOC'] = False
 558         else:
 559             # Attempt to determine the appropriate include path and
 560             # library path using pkg-config, that means we also need to
 561             # check for pkg-config. Note that it is possible to use
 562             # protobuf without the involvement of pkg-config. Later on we
 563             # check go a library config check and at that point the test
 564             # will fail if libprotobuf cannot be found.
 565             if have_pkg_config:
 566                 try:
 567                     # Attempt to establish what linking flags to add for
 568                     # protobuf
 569                     # using pkg-config
 570                     main.ParseConfig(
 571                             'pkg-config --cflags --libs-only-L protobuf')
 572                 except:
 573                     warning('pkg-config could not get protobuf flags.')
 574 except Exception as e:
 575     warning('While checking protoc version:', str(e))
 576     main['HAVE_PROTOC'] = False
 577
 578 # Check for 'timeout' from GNU coreutils. If present, regressions will
 579 # be run with a time limit. We require version 8.13 since we rely on
 580 # support for the '--foreground' option.
 581 if sys.platform.startswith('freebsd'):
 582     timeout_lines = readCommand(['gtimeout', '--version'],
 583                                 exception='').splitlines()
 584 else:
 585     timeout_lines = readCommand(['timeout', '--version'],
 586                                 exception='').splitlines()
 587 # Get the first line and tokenize it
 588 timeout_version = timeout_lines[0].split() if timeout_lines else []
 589 main['TIMEOUT'] =  timeout_version and \
 590     compareVersions(timeout_version[-1], '8.13') >= 0
 591
 592 # Add a custom Check function to test for structure members.
 593 def CheckMember(context, include, decl, member, include_quotes="<>"):
 594     context.Message("Checking for member %s in %s..." %
 595                     (member, decl))
 596     text = """
 597 #include %(header)s
 598 int main(){
 599   %(decl)s test;
 600   (void)test.%(member)s;
 601   return 0;
 602 };
 603 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 604         "decl" : decl,
 605         "member" : member,
 606         }
 607
 608     ret = context.TryCompile(text, extension=".cc")
 609     context.Result(ret)
 610     return ret
 611
 612 # Platform-specific configuration.  Note again that we assume that all
 613 # builds under a given build root run on the same host platform.
 614 conf = Configure(main,
 615                  conf_dir = joinpath(build_root, '.scons_config'),
 616                  log_file = joinpath(build_root, 'scons_config.log'),
 617                  custom_tests = {
 618         'CheckMember' : CheckMember,
 619         })
 620
 621 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 622 try:
 623     import platform
 624     uname = platform.uname()
 625     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 626         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 627             main.Append(CCFLAGS=['-arch', 'x86_64'])
 628             main.Append(CFLAGS=['-arch', 'x86_64'])
 629             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 630             main.Append(ASFLAGS=['-arch', 'x86_64'])
 631 except:
 632     pass
 633
 634 # Recent versions of scons substitute a "Null" object for Configure()
 635 # when configuration isn't necessary, e.g., if the "--help" option is
 636 # present.  Unfortuantely this Null object always returns false,
 637 # breaking all our configuration checks.  We replace it with our own
 638 # more optimistic null object that returns True instead.
 639 if not conf:
 640     def NullCheck(*args, **kwargs):
 641         return True
 642
 643     class NullConf:
 644         def __init__(self, env):
 645             self.env = env
 646         def Finish(self):
 647             return self.env
 648         def __getattr__(self, mname):
 649             return NullCheck
 650
 651     conf = NullConf(main)
 652
 653 # Cache build files in the supplied directory.
 654 if main['M5_BUILD_CACHE']:
 655     print('Using build cache located at', main['M5_BUILD_CACHE'])
 656     CacheDir(main['M5_BUILD_CACHE'])
 657
 658 main['USE_PYTHON'] = not GetOption('without_python')
 659 if main['USE_PYTHON']:
 660     # Find Python include and library directories for embedding the
 661     # interpreter. We rely on python-config to resolve the appropriate
 662     # includes and linker flags. ParseConfig does not seem to understand
 663     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 664     # we add them explicitly below. If you want to link in an alternate
 665     # version of python, see above for instructions on how to invoke
 666     # scons with the appropriate PATH set.
 667
 668     python_config = main.Detect(main['PYTHON_CONFIG'])
 669     if python_config is None:
 670         error("Can't find a suitable python-config, tried %s" % \
 671               main['PYTHON_CONFIG'])
 672
 673     print("Info: Using Python config: %s" % (python_config, ))
 674     py_includes = readCommand([python_config, '--includes'],
 675                               exception='').split()
 676     py_includes = list(filter(
 677         lambda s: match(r'.*\/include\/.*',s), py_includes))
 678     # Strip the -I from the include folders before adding them to the
 679     # CPPPATH
 680     py_includes = list(map(
 681         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 682     main.Append(CPPPATH=py_includes)
 683
 684     # Read the linker flags and split them into libraries and other link
 685     # flags. The libraries are added later through the call the CheckLib.
 686     py_ld_flags = readCommand([python_config, '--ldflags'],
 687         exception='').split()
 688     py_libs = []
 689     for lib in py_ld_flags:
 690          if not lib.startswith('-l'):
 691              main.Append(LINKFLAGS=[lib])
 692          else:
 693              lib = lib[2:]
 694              if lib not in py_libs:
 695                  py_libs.append(lib)
 696
 697     # verify that this stuff works
 698     if not conf.CheckHeader('Python.h', '<>'):
 699         error("Check failed for Python.h header in",
 700                 ' '.join(py_includes), "\n"
 701               "Two possible reasons:\n"
 702               "1. Python headers are not installed (You can install the "
 703               "package python-dev on Ubuntu and RedHat)\n"
 704               "2. SCons is using a wrong C compiler. This can happen if "
 705               "CC has the wrong value.\n"
 706               "CC = %s" % main['CC'])
 707
 708     for lib in py_libs:
 709         if not conf.CheckLib(lib):
 710             error("Can't find library %s required by python." % lib)
 711
 712 # On Solaris you need to use libsocket for socket ops
 713 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 714    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 715                                   'C++', 'accept(0,0,0);'):
 716        error("Can't find library with socket calls (e.g. accept()).")
 717
 718 # Check for zlib.  If the check passes, libz will be automatically
 719 # added to the LIBS environment variable.
 720 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 721     error('Did not find needed zlib compression library '
 722           'and/or zlib.h header file.\n'
 723           'Please install zlib and try again.')
 724
 725 # If we have the protobuf compiler, also make sure we have the
 726 # development libraries. If the check passes, libprotobuf will be
 727 # automatically added to the LIBS environment variable. After
 728 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 729 # got both protoc and libprotobuf available.
 730 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 731     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 732                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 733
 734 # Valgrind gets much less confused if you tell it when you're using
 735 # alternative stacks.
 736 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 737
 738 # If we have the compiler but not the library, print another warning.
 739 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 740     warning('Did not find protocol buffer library and/or headers.\n'
 741             'Please install libprotobuf-dev for tracing support.')
 742
 743 # Check for librt.
 744 have_posix_clock = \
 745     conf.CheckLibWithHeader(None, 'time.h', 'C',
 746                             'clock_nanosleep(0,0,NULL,NULL);') or \
 747     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 748                             'clock_nanosleep(0,0,NULL,NULL);')
 749
 750 have_posix_timers = \
 751     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 752                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 753
 754 if not GetOption('without_tcmalloc'):
 755     if conf.CheckLib('tcmalloc'):
 756         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 757     elif conf.CheckLib('tcmalloc_minimal'):
 758         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 759     else:
 760         warning("You can get a 12% performance improvement by "
 761                 "installing tcmalloc (libgoogle-perftools-dev package "
 762                 "on Ubuntu or RedHat).")
 763
 764
 765 # Detect back trace implementations. The last implementation in the
 766 # list will be used by default.
 767 backtrace_impls = [ "none" ]
 768
 769 backtrace_checker = 'char temp;' + \
 770     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 771 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 772     backtrace_impls.append("glibc")
 773 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 774                              backtrace_checker):
 775     # NetBSD and FreeBSD need libexecinfo.
 776     backtrace_impls.append("glibc")
 777     main.Append(LIBS=['execinfo'])
 778
 779 if backtrace_impls[-1] == "none":
 780     default_backtrace_impl = "none"
 781     warning("No suitable back trace implementation found.")
 782
 783 if not have_posix_clock:
 784     warning("Can't find library for POSIX clocks.")
 785
 786 # Check for <fenv.h> (C99 FP environment control)
 787 have_fenv = conf.CheckHeader('fenv.h', '<>')
 788 if not have_fenv:
 789     warning("Header file <fenv.h> not found.\n"
 790             "This host has no IEEE FP rounding mode control.")
 791
 792 # Check for <png.h> (libpng library needed if wanting to dump
 793 # frame buffer image in png format)
 794 have_png = conf.CheckHeader('png.h', '<>')
 795 if not have_png:
 796     warning("Header file <png.h> not found.\n"
 797             "This host has no libpng library.\n"
 798             "Disabling support for PNG framebuffers.")
 799
 800 # Check if we should enable KVM-based hardware virtualization. The API
 801 # we rely on exists since version 2.6.36 of the kernel, but somehow
 802 # the KVM_API_VERSION does not reflect the change. We test for one of
 803 # the types as a fall back.
 804 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 805 if not have_kvm:
 806     print("Info: Compatible header file <linux/kvm.h> not found, "
 807           "disabling KVM support.")
 808
 809 # Check if the TUN/TAP driver is available.
 810 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 811 if not have_tuntap:
 812     print("Info: Compatible header file <linux/if_tun.h> not found.")
 813
 814 # x86 needs support for xsave. We test for the structure here since we
 815 # won't be able to run new tests by the time we know which ISA we're
 816 # targeting.
 817 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 818                                     '#include <linux/kvm.h>') != 0
 819
 820 # Check if the requested target ISA is compatible with the host
 821 def is_isa_kvm_compatible(isa):
 822     try:
 823         import platform
 824         host_isa = platform.machine()
 825     except:
 826         warning("Failed to determine host ISA.")
 827         return False
 828
 829     if not have_posix_timers:
 830         warning("Can not enable KVM, host seems to lack support "
 831                 "for POSIX timers")
 832         return False
 833
 834     if isa == "arm":
 835         return host_isa in ( "armv7l", "aarch64" )
 836     elif isa == "x86":
 837         if host_isa != "x86_64":
 838             return False
 839
 840         if not have_kvm_xsave:
 841             warning("KVM on x86 requires xsave support in kernel headers.")
 842             return False
 843
 844         return True
 845     else:
 846         return False
 847
 848
 849 # Check if the exclude_host attribute is available. We want this to
 850 # get accurate instruction counts in KVM.
 851 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 852     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 853
 854 def check_hdf5():
 855     return \
 856         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 857                                 'H5Fcreate("", 0, 0, 0);') and \
 858         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 859                                 'H5::H5File("", 0);')
 860
 861 def check_hdf5_pkg(name):
 862     print("Checking for %s using pkg-config..." % name, end="")
 863     if not have_pkg_config:
 864         print(" pkg-config not found")
 865         return False
 866
 867     try:
 868         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 869         print(" yes")
 870         return True
 871     except:
 872         print(" no")
 873         return False
 874
 875 # Check if there is a pkg-config configuration for hdf5. If we find
 876 # it, setup the environment to enable linking and header inclusion. We
 877 # don't actually try to include any headers or link with hdf5 at this
 878 # stage.
 879 if not check_hdf5_pkg('hdf5-serial'):
 880     check_hdf5_pkg('hdf5')
 881
 882 # Check if the HDF5 libraries can be found. This check respects the
 883 # include path and library path provided by pkg-config. We perform
 884 # this check even if there isn't a pkg-config configuration for hdf5
 885 # since some installations don't use pkg-config.
 886 have_hdf5 = check_hdf5()
 887 if not have_hdf5:
 888     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 889     print("         HDF5 support.")
 890
 891 ######################################################################
 892 #
 893 # Finish the configuration
 894 #
 895 main = conf.Finish()
 896
 897 ######################################################################
 898 #
 899 # Collect all non-global variables
 900 #
 901
 902 # Define the universe of supported ISAs
 903 all_isa_list = [ ]
 904 all_gpu_isa_list = [ ]
 905 Export('all_isa_list')
 906 Export('all_gpu_isa_list')
 907
 908 class CpuModel(object):
 909     '''The CpuModel class encapsulates everything the ISA parser needs to
 910     know about a particular CPU model.'''
 911
 912     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 913     dict = {}
 914
 915     # Constructor.  Automatically adds models to CpuModel.dict.
 916     def __init__(self, name, default=False):
 917         self.name = name           # name of model
 918
 919         # This cpu is enabled by default
 920         self.default = default
 921
 922         # Add self to dict
 923         if name in CpuModel.dict:
 924             raise AttributeError("CpuModel '%s' already registered" % name)
 925         CpuModel.dict[name] = self
 926
 927 Export('CpuModel')
 928
 929 # Sticky variables get saved in the variables file so they persist from
 930 # one invocation to the next (unless overridden, in which case the new
 931 # value becomes sticky).
 932 sticky_vars = Variables(args=ARGUMENTS)
 933 Export('sticky_vars')
 934
 935 # Sticky variables that should be exported
 936 export_vars = []
 937 Export('export_vars')
 938
 939 # For Ruby
 940 all_protocols = []
 941 Export('all_protocols')
 942 protocol_dirs = []
 943 Export('protocol_dirs')
 944 slicc_includes = []
 945 Export('slicc_includes')
 946
 947 # Walk the tree and execute all SConsopts scripts that wil add to the
 948 # above variables
 949 if GetOption('verbose'):
 950     print("Reading SConsopts")
 951 for bdir in [ base_dir ] + extras_dir_list:
 952     if not isdir(bdir):
 953         error("Directory '%s' does not exist." % bdir)
 954     for root, dirs, files in os.walk(bdir):
 955         if 'SConsopts' in files:
 956             if GetOption('verbose'):
 957                 print("Reading", joinpath(root, 'SConsopts'))
 958             SConscript(joinpath(root, 'SConsopts'))
 959
 960 all_isa_list.sort()
 961 all_gpu_isa_list.sort()
 962
 963 sticky_vars.AddVariables(
 964     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 965     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 966     ListVariable('CPU_MODELS', 'CPU models',
 967                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 968                  sorted(CpuModel.dict.keys())),
 969     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 970                  False),
 971     BoolVariable('USE_SSE2',
 972                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 973                  False),
 974     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 975     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 976     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 977     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
 978                  False),
 979     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 980                  have_kvm),
 981     BoolVariable('USE_TUNTAP',
 982                  'Enable using a tap device to bridge to the host network',
 983                  have_tuntap),
 984     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
 985     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
 986                   all_protocols),
 987     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
 988                  backtrace_impls[-1], backtrace_impls),
 989     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
 990                  64),
 991     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
 992     )
 993
 994 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 995 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
 996                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
 997                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
 998                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
 999                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1000
1001 ###################################################
1002 #
1003 # Define a SCons builder for configuration flag headers.
1004 #
1005 ###################################################
1006
1007 # This function generates a config header file that #defines the
1008 # variable symbol to the current variable setting (0 or 1).  The source
1009 # operands are the name of the variable and a Value node containing the
1010 # value of the variable.
1011 def build_config_file(target, source, env):
1012     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
1013     with open(str(target[0]), 'w') as f:
1014         print('#define', variable, value, file=f)
1015     return None
1016
1017 # Combine the two functions into a scons Action object.
1018 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1019
1020 # The emitter munges the source & target node lists to reflect what
1021 # we're really doing.
1022 def config_emitter(target, source, env):
1023     # extract variable name from Builder arg
1024     variable = str(target[0])
1025     # True target is config header file
1026     target = joinpath('config', variable.lower() + '.hh')
1027     val = env[variable]
1028     if isinstance(val, bool):
1029         # Force value to 0/1
1030         val = int(val)
1031     elif isinstance(val, str):
1032         val = '"' + val + '"'
1033
1034     # Sources are variable name & value (packaged in SCons Value nodes)
1035     return ([target], [Value(variable), Value(val)])
1036
1037 config_builder = Builder(emitter = config_emitter, action = config_action)
1038
1039 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1040
1041 ###################################################
1042 #
1043 # Builders for static and shared partially linked object files.
1044 #
1045 ###################################################
1046
1047 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1048                                  src_suffix='$OBJSUFFIX',
1049                                  src_builder=['StaticObject', 'Object'],
1050                                  LINKFLAGS='$PLINKFLAGS',
1051                                  LIBS='')
1052
1053 def partial_shared_emitter(target, source, env):
1054     for tgt in target:
1055         tgt.attributes.shared = 1
1056     return (target, source)
1057 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1058                                  emitter=partial_shared_emitter,
1059                                  src_suffix='$SHOBJSUFFIX',
1060                                  src_builder='SharedObject',
1061                                  SHLINKFLAGS='$PSHLINKFLAGS',
1062                                  LIBS='')
1063
1064 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1065                          'PartialStatic' : partial_static_builder })
1066
1067 def add_local_rpath(env, *targets):
1068     '''Set up an RPATH for a library which lives in the build directory.
1069
1070     The construction environment variable BIN_RPATH_PREFIX should be set to
1071     the relative path of the build directory starting from the location of the
1072     binary.'''
1073     for target in targets:
1074         target = env.Entry(target)
1075         if not isinstance(target, SCons.Node.FS.Dir):
1076             target = target.dir
1077         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1078         components = [
1079             '\\$$ORIGIN',
1080             '${BIN_RPATH_PREFIX}',
1081             relpath
1082         ]
1083         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1084
1085 if sys.platform != "darwin":
1086     main.Append(LINKFLAGS=Split('-z origin'))
1087
1088 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1089
1090 # builds in ext are shared across all configs in the build root.
1091 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1092 ext_build_dirs = []
1093 for root, dirs, files in os.walk(ext_dir):
1094     if 'SConscript' in files:
1095         build_dir = os.path.relpath(root, ext_dir)
1096         ext_build_dirs.append(build_dir)
1097         main.SConscript(joinpath(root, 'SConscript'),
1098                         variant_dir=joinpath(build_root, build_dir))
1099
1100 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1101 Export('gdb_xml_dir')
1102
1103 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1104
1105 ###################################################
1106 #
1107 # This builder and wrapper method are used to set up a directory with
1108 # switching headers. Those are headers which are in a generic location and
1109 # that include more specific headers from a directory chosen at build time
1110 # based on the current build settings.
1111 #
1112 ###################################################
1113
1114 def build_switching_header(target, source, env):
1115     path = str(target[0])
1116     subdir = str(source[0])
1117     dp, fp = os.path.split(path)
1118     dp = os.path.relpath(os.path.realpath(dp),
1119                          os.path.realpath(env['BUILDDIR']))
1120     with open(path, 'w') as hdr:
1121         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1122
1123 switching_header_action = MakeAction(build_switching_header,
1124                                      Transform('GENERATE'))
1125
1126 switching_header_builder = Builder(action=switching_header_action,
1127                                    source_factory=Value,
1128                                    single_source=True)
1129
1130 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1131
1132 def switching_headers(self, headers, source):
1133     for header in headers:
1134         self.SwitchingHeader(header, source)
1135
1136 main.AddMethod(switching_headers, 'SwitchingHeaders')
1137
1138 ###################################################
1139 #
1140 # Define build environments for selected configurations.
1141 #
1142 ###################################################
1143
1144 for variant_path in variant_paths:
1145     if not GetOption('silent'):
1146         print("Building in", variant_path)
1147
1148     # Make a copy of the build-root environment to use for this config.
1149     env = main.Clone()
1150     env['BUILDDIR'] = variant_path
1151
1152     # variant_dir is the tail component of build path, and is used to
1153     # determine the build parameters (e.g., 'X86')
1154     (build_root, variant_dir) = splitpath(variant_path)
1155
1156     # Set env variables according to the build directory config.
1157     sticky_vars.files = []
1158     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1159     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1160     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1161     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1162     if isfile(current_vars_file):
1163         sticky_vars.files.append(current_vars_file)
1164         if not GetOption('silent'):
1165             print("Using saved variables file %s" % current_vars_file)
1166     elif variant_dir in ext_build_dirs:
1167         # Things in ext are built without a variant directory.
1168         continue
1169     else:
1170         # Build dir-specific variables file doesn't exist.
1171
1172         # Make sure the directory is there so we can create it later
1173         opt_dir = dirname(current_vars_file)
1174         if not isdir(opt_dir):
1175             mkdir(opt_dir)
1176
1177         # Get default build variables from source tree.  Variables are
1178         # normally determined by name of $VARIANT_DIR, but can be
1179         # overridden by '--default=' arg on command line.
1180         default = GetOption('default')
1181         opts_dir = joinpath(main.root.abspath, 'build_opts')
1182         if default:
1183             default_vars_files = [joinpath(build_root, 'variables', default),
1184                                   joinpath(opts_dir, default)]
1185         else:
1186             default_vars_files = [joinpath(opts_dir, variant_dir)]
1187         existing_files = list(filter(isfile, default_vars_files))
1188         if existing_files:
1189             default_vars_file = existing_files[0]
1190             sticky_vars.files.append(default_vars_file)
1191             print("Variables file %s not found,\n  using defaults in %s"
1192                   % (current_vars_file, default_vars_file))
1193         else:
1194             error("Cannot find variables file %s or default file(s) %s"
1195                   % (current_vars_file, ' or '.join(default_vars_files)))
1196             Exit(1)
1197
1198     # Apply current variable settings to env
1199     sticky_vars.Update(env)
1200
1201     help_texts["local_vars"] += \
1202         "Build variables for %s:\n" % variant_dir \
1203                  + sticky_vars.GenerateHelpText(env)
1204
1205     # Process variable settings.
1206
1207     if not have_fenv and env['USE_FENV']:
1208         warning("<fenv.h> not available; forcing USE_FENV to False in",
1209                 variant_dir + ".")
1210         env['USE_FENV'] = False
1211
1212     if not env['USE_FENV']:
1213         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1214                 "FP results may deviate slightly from other platforms.")
1215
1216     if not have_png and env['USE_PNG']:
1217         warning("<png.h> not available; forcing USE_PNG to False in",
1218                 variant_dir + ".")
1219         env['USE_PNG'] = False
1220
1221     if env['USE_PNG']:
1222         env.Append(LIBS=['png'])
1223
1224     if env['EFENCE']:
1225         env.Append(LIBS=['efence'])
1226
1227     if env['USE_KVM']:
1228         if not have_kvm:
1229             warning("Can not enable KVM, host seems to lack KVM support")
1230             env['USE_KVM'] = False
1231         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1232             print("Info: KVM support disabled due to unsupported host and "
1233                   "target ISA combination")
1234             env['USE_KVM'] = False
1235
1236     if env['USE_TUNTAP']:
1237         if not have_tuntap:
1238             warning("Can't connect EtherTap with a tap device.")
1239             env['USE_TUNTAP'] = False
1240
1241     if env['BUILD_GPU']:
1242         env.Append(CPPDEFINES=['BUILD_GPU'])
1243
1244     # Warn about missing optional functionality
1245     if env['USE_KVM']:
1246         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1247             warning("perf_event headers lack support for the exclude_host "
1248                     "attribute. KVM instruction counts will be inaccurate.")
1249
1250     # Save sticky variable settings back to current variables file
1251     sticky_vars.Save(current_vars_file, env)
1252
1253     if env['USE_SSE2']:
1254         env.Append(CCFLAGS=['-msse2'])
1255
1256     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1257     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1258
1259     # The src/SConscript file sets up the build rules in 'env' according
1260     # to the configured variables.  It returns a list of environments,
1261     # one for each variant build (debug, opt, etc.)
1262     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1263
1264 # base help text
1265 Help('''
1266 Usage: scons [scons options] [build variables] [target(s)]
1267
1268 Extra scons options:
1269 %(options)s
1270
1271 Global build variables:
1272 %(global_vars)s
1273
1274 %(local_vars)s
1275 ''' % help_texts)
1276
1277 atexit.register(summarize_warnings)