SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2013, 2015-2020 ARM Limited
   4 # All rights reserved.
   5 #
   6 # The license below extends only to copyright in the software and shall
   7 # not be construed as granting a license to any other intellectual
   8 # property including but not limited to intellectual property relating
   9 # to a hardware implementation of the functionality of the software
  10 # licensed hereunder.  You may use the software subject to the license
  11 # terms below provided that you ensure that this notice is replicated
  12 # unmodified and in its entirety in all distributions of the software,
  13 # modified or unmodified, in source code or in binary form.
  14 #
  15 # Copyright (c) 2011 Advanced Micro Devices, Inc.
  16 # Copyright (c) 2009 The Hewlett-Packard Development Company
  17 # Copyright (c) 2004-2005 The Regents of The University of Michigan
  18 # All rights reserved.
  19 #
  20 # Redistribution and use in source and binary forms, with or without
  21 # modification, are permitted provided that the following conditions are
  22 # met: redistributions of source code must retain the above copyright
  23 # notice, this list of conditions and the following disclaimer;
  24 # redistributions in binary form must reproduce the above copyright
  25 # notice, this list of conditions and the following disclaimer in the
  26 # documentation and/or other materials provided with the distribution;
  27 # neither the name of the copyright holders nor the names of its
  28 # contributors may be used to endorse or promote products derived from
  29 # this software without specific prior written permission.
  30 #
  31 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42
  43 ###################################################
  44 #
  45 # SCons top-level build description (SConstruct) file.
  46 #
  47 # While in this directory ('gem5'), just type 'scons' to build the default
  48 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
  49 # to build some other configuration (e.g., 'build/X86/gem5.opt' for
  50 # the optimized full-system version).
  51 #
  52 # You can build gem5 in a different directory as long as there is a
  53 # 'build/<CONFIG>' somewhere along the target path.  The build system
  54 # expects that all configs under the same build directory are being
  55 # built for the same host system.
  56 #
  57 # Examples:
  58 #
  59 #   The following two commands are equivalent.  The '-u' option tells
  60 #   scons to search up the directory tree for this SConstruct file.
  61 #   % cd <path-to-src>/gem5 ; scons build/X86/gem5.debug
  62 #   % cd <path-to-src>/gem5/build/X86; scons -u gem5.debug
  63 #
  64 #   The following two commands are equivalent and demonstrate building
  65 #   in a directory outside of the source tree.  The '-C' option tells
  66 #   scons to chdir to the specified directory to find this SConstruct
  67 #   file.
  68 #   % cd <path-to-src>/gem5 ; scons /local/foo/build/X86/gem5.debug
  69 #   % cd /local/foo/build/X86; scons -C <path-to-src>/gem5 gem5.debug
  70 #
  71 # You can use 'scons -H' to print scons options.  If you're in this
  72 # 'gem5' directory (or use -u or -C to tell scons where to find this
  73 # file), you can use 'scons -h' to print all the gem5-specific build
  74 # options as well.
  75 #
  76 ###################################################
  77
  78 from __future__ import print_function
  79
  80 # Global Python includes
  81 import atexit
  82 import itertools
  83 import os
  84 import re
  85 import shutil
  86 import subprocess
  87 import sys
  88
  89 from os import mkdir, environ
  90 from os.path import abspath, basename, dirname, expanduser, normpath
  91 from os.path import exists,  isdir, isfile
  92 from os.path import join as joinpath, split as splitpath
  93 from re import match
  94
  95 # SCons includes
  96 import SCons
  97 import SCons.Node
  98 import SCons.Node.FS
  99
 100 from m5.util import compareVersions, readCommand, readCommandWithReturn
 101
 102 AddOption('--colors', dest='use_colors', action='store_true',
 103           help="Add color to abbreviated scons output")
 104 AddOption('--no-colors', dest='use_colors', action='store_false',
 105           help="Don't add color to abbreviated scons output")
 106 AddOption('--with-cxx-config', action='store_true',
 107           help="Build with support for C++-based configuration")
 108 AddOption('--default',
 109           help='Override which build_opts file to use for defaults')
 110 AddOption('--ignore-style', action='store_true',
 111           help='Disable style checking hooks')
 112 AddOption('--gold-linker', action='store_true', help='Use the gold linker')
 113 AddOption('--no-lto', action='store_true',
 114           help='Disable Link-Time Optimization for fast')
 115 AddOption('--force-lto', action='store_true',
 116           help='Use Link-Time Optimization instead of partial linking' +
 117                ' when the compiler doesn\'t support using them together.')
 118 AddOption('--verbose', action='store_true',
 119           help='Print full tool command lines')
 120 AddOption('--without-python', action='store_true',
 121           help='Build without Python configuration support')
 122 AddOption('--without-tcmalloc', action='store_true',
 123           help='Disable linking against tcmalloc')
 124 AddOption('--with-ubsan', action='store_true',
 125           help='Build with Undefined Behavior Sanitizer if available')
 126 AddOption('--with-asan', action='store_true',
 127           help='Build with Address Sanitizer if available')
 128 AddOption('--with-systemc-tests', action='store_true',
 129           help='Build systemc tests')
 130
 131 from gem5_scons import Transform, error, warning, summarize_warnings
 132
 133 if GetOption('no_lto') and GetOption('force_lto'):
 134     error('--no-lto and --force-lto are mutually exclusive')
 135
 136 ########################################################################
 137 #
 138 # Set up the main build environment.
 139 #
 140 ########################################################################
 141
 142 main = Environment()
 143
 144 from gem5_scons.util import get_termcap
 145 termcap = get_termcap()
 146
 147 main_dict_keys = main.Dictionary().keys()
 148
 149 # Check that we have a C/C++ compiler
 150 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 151     error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 152
 153 ###################################################
 154 #
 155 # Figure out which configurations to set up based on the path(s) of
 156 # the target(s).
 157 #
 158 ###################################################
 159
 160 # Find default configuration & binary.
 161 Default(environ.get('M5_DEFAULT_BINARY', 'build/ARM/gem5.debug'))
 162
 163 # helper function: find last occurrence of element in list
 164 def rfind(l, elt, offs = -1):
 165     for i in range(len(l)+offs, 0, -1):
 166         if l[i] == elt:
 167             return i
 168     raise ValueError("element not found")
 169
 170 # Take a list of paths (or SCons Nodes) and return a list with all
 171 # paths made absolute and ~-expanded.  Paths will be interpreted
 172 # relative to the launch directory unless a different root is provided
 173 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 174     return [abspath(joinpath(root, expanduser(str(p))))
 175             for p in path_list]
 176
 177 # Each target must have 'build' in the interior of the path; the
 178 # directory below this will determine the build parameters.  For
 179 # example, for target 'foo/bar/build/X86/arch/x86/blah.do' we
 180 # recognize that X86 specifies the configuration because it
 181 # follow 'build' in the build path.
 182
 183 # The funky assignment to "[:]" is needed to replace the list contents
 184 # in place rather than reassign the symbol to a new list, which
 185 # doesn't work (obviously!).
 186 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 187
 188 # Generate a list of the unique build roots and configs that the
 189 # collected targets reference.
 190 variant_paths = []
 191 build_root = None
 192 for t in BUILD_TARGETS:
 193     path_dirs = t.split('/')
 194     try:
 195         build_top = rfind(path_dirs, 'build', -2)
 196     except:
 197         error("No non-leaf 'build' dir found on target path.", t)
 198     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 199     if not build_root:
 200         build_root = this_build_root
 201     else:
 202         if this_build_root != build_root:
 203             error("build targets not under same build root\n"
 204                   "  %s\n  %s" % (build_root, this_build_root))
 205     variant_path = joinpath('/',*path_dirs[:build_top+2])
 206     if variant_path not in variant_paths:
 207         variant_paths.append(variant_path)
 208
 209 # Make sure build_root exists (might not if this is the first build there)
 210 if not isdir(build_root):
 211     mkdir(build_root)
 212 main['BUILDROOT'] = build_root
 213
 214 Export('main')
 215
 216 main.SConsignFile(joinpath(build_root, "sconsign"))
 217
 218 # Default duplicate option is to use hard links, but this messes up
 219 # when you use emacs to edit a file in the target dir, as emacs moves
 220 # file to file~ then copies to file, breaking the link.  Symbolic
 221 # (soft) links work better.
 222 main.SetOption('duplicate', 'soft-copy')
 223
 224 #
 225 # Set up global sticky variables... these are common to an entire build
 226 # tree (not specific to a particular build like X86)
 227 #
 228
 229 global_vars_file = joinpath(build_root, 'variables.global')
 230
 231 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 232
 233 global_vars.AddVariables(
 234     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 235     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 236     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 237     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 238     ('MARSHAL_CCFLAGS_EXTRA', 'Extra C and C++ marshal compiler flags', ''),
 239     ('MARSHAL_LDFLAGS_EXTRA', 'Extra marshal linker flags', ''),
 240     ('PYTHON_CONFIG', 'Python config binary to use',
 241      [ 'python2.7-config', 'python-config', 'python3-config' ]),
 242     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 243     ('BATCH', 'Use batch pool for build and tests', False),
 244     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 245     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 246     ('EXTRAS', 'Add extra directories to the compilation', '')
 247     )
 248
 249 # Update main environment with values from ARGUMENTS & global_vars_file
 250 global_vars.Update(main)
 251 Help('''
 252 Global build variables:
 253 {help}
 254 '''.format(help=global_vars.GenerateHelpText(main)), append=True)
 255
 256 # Save sticky variable settings back to current variables file
 257 global_vars.Save(global_vars_file, main)
 258
 259 # Parse EXTRAS variable to build list of all directories where we're
 260 # look for sources etc.  This list is exported as extras_dir_list.
 261 base_dir = main.srcdir.abspath
 262 if main['EXTRAS']:
 263     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 264 else:
 265     extras_dir_list = []
 266
 267 Export('base_dir')
 268 Export('extras_dir_list')
 269
 270 # the ext directory should be on the #includes path
 271 main.Append(CPPPATH=[Dir('ext')])
 272
 273 # Add shared top-level headers
 274 main.Prepend(CPPPATH=Dir('include'))
 275
 276 if GetOption('verbose'):
 277     def MakeAction(action, string, *args, **kwargs):
 278         return Action(action, *args, **kwargs)
 279 else:
 280     MakeAction = Action
 281     main['CCCOMSTR']        = Transform("CC")
 282     main['CXXCOMSTR']       = Transform("CXX")
 283     main['ASCOMSTR']        = Transform("AS")
 284     main['ARCOMSTR']        = Transform("AR", 0)
 285     main['LINKCOMSTR']      = Transform("LINK", 0)
 286     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 287     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 288     main['M4COMSTR']        = Transform("M4")
 289     main['SHCCCOMSTR']      = Transform("SHCC")
 290     main['SHCXXCOMSTR']     = Transform("SHCXX")
 291 Export('MakeAction')
 292
 293 # Initialize the Link-Time Optimization (LTO) flags
 294 main['LTO_CCFLAGS'] = []
 295 main['LTO_LDFLAGS'] = []
 296
 297 # According to the readme, tcmalloc works best if the compiler doesn't
 298 # assume that we're using the builtin malloc and friends. These flags
 299 # are compiler-specific, so we need to set them after we detect which
 300 # compiler we're using.
 301 main['TCMALLOC_CCFLAGS'] = []
 302
 303 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 304 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 305
 306 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 307 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 308 if main['GCC'] + main['CLANG'] > 1:
 309     error('Two compilers enabled at once?')
 310
 311 # Set up default C++ compiler flags
 312 if main['GCC'] or main['CLANG']:
 313     # As gcc and clang share many flags, do the common parts here
 314     main.Append(CCFLAGS=['-pipe'])
 315     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 316     # Enable -Wall and -Wextra and then disable the few warnings that
 317     # we consistently violate
 318     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 319                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 320     # We always compile using C++11
 321     main.Append(CXXFLAGS=['-std=c++11'])
 322     if sys.platform.startswith('freebsd'):
 323         main.Append(CCFLAGS=['-I/usr/local/include'])
 324         main.Append(CXXFLAGS=['-I/usr/local/include'])
 325
 326     # On Mac OS X/Darwin the default linker doesn't support the
 327     # option --as-needed
 328     if sys.platform != "darwin":
 329         main.Append(LINKFLAGS='-Wl,--as-needed')
 330     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 331     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 332     if GetOption('gold_linker'):
 333         main.Append(LINKFLAGS='-fuse-ld=gold')
 334     main['PLINKFLAGS'] = main.get('LINKFLAGS')
 335     shared_partial_flags = ['-r', '-nostdlib']
 336     main.Append(PSHLINKFLAGS=shared_partial_flags)
 337     main.Append(PLINKFLAGS=shared_partial_flags)
 338
 339     # Treat warnings as errors but white list some warnings that we
 340     # want to allow (e.g., deprecation warnings).
 341     main.Append(CCFLAGS=['-Werror',
 342                          '-Wno-error=deprecated-declarations',
 343                          '-Wno-error=deprecated',
 344                         ])
 345 else:
 346     error('\n'.join((
 347           "Don't know what compiler options to use for your compiler.",
 348           "compiler: " + main['CXX'],
 349           "version: " + CXX_version.replace('\n', '<nl>') if
 350                 CXX_version else 'COMMAND NOT FOUND!',
 351           "If you're trying to use a compiler other than GCC",
 352           "or clang, there appears to be something wrong with your",
 353           "environment.",
 354           "",
 355           "If you are trying to use a compiler other than those listed",
 356           "above you will need to ease fix SConstruct and ",
 357           "src/SConscript to support that compiler.")))
 358
 359 if main['GCC']:
 360     # Check for a supported version of gcc. >= 4.8 is chosen for its
 361     # level of c++11 support. See
 362     # http://gcc.gnu.org/projects/cxx0x.html for details.
 363     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 364     if compareVersions(gcc_version, "4.8") < 0:
 365         error('gcc version 4.8 or newer required.\n'
 366               'Installed version:', gcc_version)
 367         Exit(1)
 368
 369     main['GCC_VERSION'] = gcc_version
 370
 371     if compareVersions(gcc_version, '4.9') >= 0:
 372         # Incremental linking with LTO is currently broken in gcc versions
 373         # 4.9 and above. A version where everything works completely hasn't
 374         # yet been identified.
 375         #
 376         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 377         main['BROKEN_INCREMENTAL_LTO'] = True
 378     if compareVersions(gcc_version, '6.0') >= 0:
 379         # gcc versions 6.0 and greater accept an -flinker-output flag which
 380         # selects what type of output the linker should generate. This is
 381         # necessary for incremental lto to work, but is also broken in
 382         # current versions of gcc. It may not be necessary in future
 383         # versions. We add it here since it might be, and as a reminder that
 384         # it exists. It's excluded if lto is being forced.
 385         #
 386         # https://gcc.gnu.org/gcc-6/changes.html
 387         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 388         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 389         if not GetOption('force_lto'):
 390             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 391             main.Append(PLINKFLAGS='-flinker-output=rel')
 392
 393     disable_lto = GetOption('no_lto')
 394     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 395             not GetOption('force_lto'):
 396         warning('Your compiler doesn\'t support incremental linking and lto '
 397                 'at the same time, so lto is being disabled. To force lto on '
 398                 'anyway, use the --force-lto option. That will disable '
 399                 'partial linking.')
 400         disable_lto = True
 401
 402     # Add the appropriate Link-Time Optimization (LTO) flags
 403     # unless LTO is explicitly turned off. Note that these flags
 404     # are only used by the fast target.
 405     if not disable_lto:
 406         # Pass the LTO flag when compiling to produce GIMPLE
 407         # output, we merely create the flags here and only append
 408         # them later
 409         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 410
 411         # Use the same amount of jobs for LTO as we are running
 412         # scons with
 413         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 414
 415     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 416                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 417
 418 elif main['CLANG']:
 419     # Check for a supported version of clang, >= 3.1 is needed to
 420     # support similar features as gcc 4.8. See
 421     # http://clang.llvm.org/cxx_status.html for details
 422     clang_version_re = re.compile(".* version (\d+\.\d+)")
 423     clang_version_match = clang_version_re.search(CXX_version)
 424     if (clang_version_match):
 425         clang_version = clang_version_match.groups()[0]
 426         if compareVersions(clang_version, "3.1") < 0:
 427             error('clang version 3.1 or newer required.\n'
 428                   'Installed version:', clang_version)
 429     else:
 430         error('Unable to determine clang version.')
 431
 432     # clang has a few additional warnings that we disable, extraneous
 433     # parantheses are allowed due to Ruby's printing of the AST,
 434     # finally self assignments are allowed as the generated CPU code
 435     # is relying on this
 436     main.Append(CCFLAGS=['-Wno-parentheses',
 437                          '-Wno-self-assign',
 438                          # Some versions of libstdc++ (4.8?) seem to
 439                          # use struct hash and class hash
 440                          # interchangeably.
 441                          '-Wno-mismatched-tags',
 442                          ])
 443     if sys.platform != "darwin" and \
 444        compareVersions(clang_version, "10.0") >= 0:
 445         main.Append(CCFLAGS=['-Wno-c99-designator'])
 446
 447     if compareVersions(clang_version, "8.0") >= 0:
 448         main.Append(CCFLAGS=['-Wno-defaulted-function-deleted'])
 449
 450     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 451
 452     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 453     # opposed to libstdc++, as the later is dated.
 454     if sys.platform == "darwin":
 455         main.Append(CXXFLAGS=['-stdlib=libc++'])
 456         main.Append(LIBS=['c++'])
 457
 458     # On FreeBSD we need libthr.
 459     if sys.platform.startswith('freebsd'):
 460         main.Append(LIBS=['thr'])
 461
 462 # Add sanitizers flags
 463 sanitizers=[]
 464 if GetOption('with_ubsan'):
 465     # Only gcc >= 4.9 supports UBSan, so check both the version
 466     # and the command-line option before adding the compiler and
 467     # linker flags.
 468     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 469         sanitizers.append('undefined')
 470 if GetOption('with_asan'):
 471     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 472     # by the build system
 473     sanitizers.append('address')
 474     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 475     suppressions_opt = 'suppressions=%s' % suppressions_file
 476     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 477                                             'print_suppressions=0'])
 478     print()
 479     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 480             'environment variable to "%s" when running gem5' %
 481             suppressions_opt)
 482     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 483     print()
 484 if sanitizers:
 485     sanitizers = ','.join(sanitizers)
 486     if main['GCC'] or main['CLANG']:
 487         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 488                              '-fno-omit-frame-pointer'],
 489                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 490     else:
 491         warning("Don't know how to enable %s sanitizer(s) for your "
 492                 "compiler." % sanitizers)
 493
 494 # Set up common yacc/bison flags (needed for Ruby)
 495 main['YACCFLAGS'] = '-d'
 496 main['YACCHXXFILESUFFIX'] = '.hh'
 497
 498 # Do this after we save setting back, or else we'll tack on an
 499 # extra 'qdo' every time we run scons.
 500 if main['BATCH']:
 501     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 502     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 503     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 504     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 505     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 506
 507 if sys.platform == 'cygwin':
 508     # cygwin has some header file issues...
 509     main.Append(CCFLAGS=["-Wno-uninitialized"])
 510
 511
 512 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 513
 514 # Check for the protobuf compiler
 515 try:
 516     main['HAVE_PROTOC'] = True
 517     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 518
 519     # First two words should be "libprotoc x.y.z"
 520     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 521         warning('Protocol buffer compiler (protoc) not found.\n'
 522                 'Please install protobuf-compiler for tracing support.')
 523         main['HAVE_PROTOC'] = False
 524     else:
 525         # Based on the availability of the compress stream wrappers,
 526         # require 2.1.0
 527         min_protoc_version = '2.1.0'
 528         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 529             warning('protoc version', min_protoc_version,
 530                     'or newer required.\n'
 531                     'Installed version:', protoc_version[1])
 532             main['HAVE_PROTOC'] = False
 533         else:
 534             # Attempt to determine the appropriate include path and
 535             # library path using pkg-config, that means we also need to
 536             # check for pkg-config. Note that it is possible to use
 537             # protobuf without the involvement of pkg-config. Later on we
 538             # check go a library config check and at that point the test
 539             # will fail if libprotobuf cannot be found.
 540             if have_pkg_config:
 541                 try:
 542                     # Attempt to establish what linking flags to add for
 543                     # protobuf
 544                     # using pkg-config
 545                     main.ParseConfig(
 546                             'pkg-config --cflags --libs-only-L protobuf')
 547                 except:
 548                     warning('pkg-config could not get protobuf flags.')
 549 except Exception as e:
 550     warning('While checking protoc version:', str(e))
 551     main['HAVE_PROTOC'] = False
 552
 553 # Check for 'timeout' from GNU coreutils. If present, regressions will
 554 # be run with a time limit. We require version 8.13 since we rely on
 555 # support for the '--foreground' option.
 556 if sys.platform.startswith('freebsd'):
 557     timeout_lines = readCommand(['gtimeout', '--version'],
 558                                 exception='').splitlines()
 559 else:
 560     timeout_lines = readCommand(['timeout', '--version'],
 561                                 exception='').splitlines()
 562 # Get the first line and tokenize it
 563 timeout_version = timeout_lines[0].split() if timeout_lines else []
 564 main['TIMEOUT'] =  timeout_version and \
 565     compareVersions(timeout_version[-1], '8.13') >= 0
 566
 567 # Add a custom Check function to test for structure members.
 568 def CheckMember(context, include, decl, member, include_quotes="<>"):
 569     context.Message("Checking for member %s in %s..." %
 570                     (member, decl))
 571     text = """
 572 #include %(header)s
 573 int main(){
 574   %(decl)s test;
 575   (void)test.%(member)s;
 576   return 0;
 577 };
 578 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 579         "decl" : decl,
 580         "member" : member,
 581         }
 582
 583     ret = context.TryCompile(text, extension=".cc")
 584     context.Result(ret)
 585     return ret
 586
 587 # Platform-specific configuration.  Note again that we assume that all
 588 # builds under a given build root run on the same host platform.
 589 conf = Configure(main,
 590                  conf_dir = joinpath(build_root, '.scons_config'),
 591                  log_file = joinpath(build_root, 'scons_config.log'),
 592                  custom_tests = {
 593         'CheckMember' : CheckMember,
 594         })
 595
 596 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 597 try:
 598     import platform
 599     uname = platform.uname()
 600     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 601         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 602             main.Append(CCFLAGS=['-arch', 'x86_64'])
 603             main.Append(CFLAGS=['-arch', 'x86_64'])
 604             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 605             main.Append(ASFLAGS=['-arch', 'x86_64'])
 606 except:
 607     pass
 608
 609 # Recent versions of scons substitute a "Null" object for Configure()
 610 # when configuration isn't necessary, e.g., if the "--help" option is
 611 # present.  Unfortuantely this Null object always returns false,
 612 # breaking all our configuration checks.  We replace it with our own
 613 # more optimistic null object that returns True instead.
 614 if not conf:
 615     def NullCheck(*args, **kwargs):
 616         return True
 617
 618     class NullConf:
 619         def __init__(self, env):
 620             self.env = env
 621         def Finish(self):
 622             return self.env
 623         def __getattr__(self, mname):
 624             return NullCheck
 625
 626     conf = NullConf(main)
 627
 628 # Cache build files in the supplied directory.
 629 if main['M5_BUILD_CACHE']:
 630     print('Using build cache located at', main['M5_BUILD_CACHE'])
 631     CacheDir(main['M5_BUILD_CACHE'])
 632
 633 main['USE_PYTHON'] = not GetOption('without_python')
 634 if main['USE_PYTHON']:
 635     # Find Python include and library directories for embedding the
 636     # interpreter. We rely on python-config to resolve the appropriate
 637     # includes and linker flags. ParseConfig does not seem to understand
 638     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 639     # we add them explicitly below. If you want to link in an alternate
 640     # version of python, see above for instructions on how to invoke
 641     # scons with the appropriate PATH set.
 642
 643     python_config = main.Detect(main['PYTHON_CONFIG'])
 644     if python_config is None:
 645         error("Can't find a suitable python-config, tried %s" % \
 646               main['PYTHON_CONFIG'])
 647
 648     print("Info: Using Python config: %s" % (python_config, ))
 649     py_includes = readCommand([python_config, '--includes'],
 650                               exception='').split()
 651     py_includes = list(filter(
 652         lambda s: match(r'.*\/include\/.*',s), py_includes))
 653     # Strip the -I from the include folders before adding them to the
 654     # CPPPATH
 655     py_includes = list(map(
 656         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 657     main.Append(CPPPATH=py_includes)
 658
 659     # Read the linker flags and split them into libraries and other link
 660     # flags. The libraries are added later through the call the CheckLib.
 661     # Note: starting in Python 3.8 the --embed flag is required to get the
 662     # -lpython3.8 linker flag
 663     retcode, cmd_stdout = readCommandWithReturn(
 664         [python_config, '--ldflags', '--embed'], exception='')
 665     if retcode != 0:
 666         # If --embed isn't detected then we're running python <3.8
 667         retcode, cmd_stdout = readCommandWithReturn(
 668             [python_config, '--ldflags'], exception='')
 669
 670     # Checking retcode again
 671     if retcode != 0:
 672         error("Failing on python-config --ldflags command")
 673
 674     py_ld_flags = cmd_stdout.split()
 675
 676     py_libs = []
 677     for lib in py_ld_flags:
 678          if not lib.startswith('-l'):
 679              main.Append(LINKFLAGS=[lib])
 680          else:
 681              lib = lib[2:]
 682              if lib not in py_libs:
 683                  py_libs.append(lib)
 684
 685     # verify that this stuff works
 686     if not conf.CheckHeader('Python.h', '<>'):
 687         error("Check failed for Python.h header in",
 688                 ' '.join(py_includes), "\n"
 689               "Two possible reasons:\n"
 690               "1. Python headers are not installed (You can install the "
 691               "package python-dev on Ubuntu and RedHat)\n"
 692               "2. SCons is using a wrong C compiler. This can happen if "
 693               "CC has the wrong value.\n"
 694               "CC = %s" % main['CC'])
 695
 696     for lib in py_libs:
 697         if not conf.CheckLib(lib):
 698             error("Can't find library %s required by python." % lib)
 699
 700 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
 701 # Bare minimum environment that only includes python
 702 marshal_env = main.Clone()
 703 marshal_env.Append(CCFLAGS='$MARSHAL_CCFLAGS_EXTRA')
 704 marshal_env.Append(LINKFLAGS='$MARSHAL_LDFLAGS_EXTRA')
 705
 706 # On Solaris you need to use libsocket for socket ops
 707 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 708    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 709                                   'C++', 'accept(0,0,0);'):
 710        error("Can't find library with socket calls (e.g. accept()).")
 711
 712 # Check for zlib.  If the check passes, libz will be automatically
 713 # added to the LIBS environment variable.
 714 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 715     error('Did not find needed zlib compression library '
 716           'and/or zlib.h header file.\n'
 717           'Please install zlib and try again.')
 718
 719 # If we have the protobuf compiler, also make sure we have the
 720 # development libraries. If the check passes, libprotobuf will be
 721 # automatically added to the LIBS environment variable. After
 722 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 723 # got both protoc and libprotobuf available.
 724 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 725     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 726                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 727
 728 # Valgrind gets much less confused if you tell it when you're using
 729 # alternative stacks.
 730 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 731
 732 # If we have the compiler but not the library, print another warning.
 733 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 734     warning('Did not find protocol buffer library and/or headers.\n'
 735             'Please install libprotobuf-dev for tracing support.')
 736
 737 # Check for librt.
 738 have_posix_clock = \
 739     conf.CheckLibWithHeader(None, 'time.h', 'C',
 740                             'clock_nanosleep(0,0,NULL,NULL);') or \
 741     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 742                             'clock_nanosleep(0,0,NULL,NULL);')
 743
 744 have_posix_timers = \
 745     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 746                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 747
 748 if not GetOption('without_tcmalloc'):
 749     if conf.CheckLib('tcmalloc'):
 750         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 751     elif conf.CheckLib('tcmalloc_minimal'):
 752         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 753     else:
 754         warning("You can get a 12% performance improvement by "
 755                 "installing tcmalloc (libgoogle-perftools-dev package "
 756                 "on Ubuntu or RedHat).")
 757
 758
 759 # Detect back trace implementations. The last implementation in the
 760 # list will be used by default.
 761 backtrace_impls = [ "none" ]
 762
 763 backtrace_checker = 'char temp;' + \
 764     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 765 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 766     backtrace_impls.append("glibc")
 767 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 768                              backtrace_checker):
 769     # NetBSD and FreeBSD need libexecinfo.
 770     backtrace_impls.append("glibc")
 771     main.Append(LIBS=['execinfo'])
 772
 773 if backtrace_impls[-1] == "none":
 774     default_backtrace_impl = "none"
 775     warning("No suitable back trace implementation found.")
 776
 777 if not have_posix_clock:
 778     warning("Can't find library for POSIX clocks.")
 779
 780 # Check for <fenv.h> (C99 FP environment control)
 781 have_fenv = conf.CheckHeader('fenv.h', '<>')
 782 if not have_fenv:
 783     warning("Header file <fenv.h> not found.\n"
 784             "This host has no IEEE FP rounding mode control.")
 785
 786 # Check for <png.h> (libpng library needed if wanting to dump
 787 # frame buffer image in png format)
 788 have_png = conf.CheckHeader('png.h', '<>')
 789 if not have_png:
 790     warning("Header file <png.h> not found.\n"
 791             "This host has no libpng library.\n"
 792             "Disabling support for PNG framebuffers.")
 793
 794 # Check if we should enable KVM-based hardware virtualization. The API
 795 # we rely on exists since version 2.6.36 of the kernel, but somehow
 796 # the KVM_API_VERSION does not reflect the change. We test for one of
 797 # the types as a fall back.
 798 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 799 if not have_kvm:
 800     print("Info: Compatible header file <linux/kvm.h> not found, "
 801           "disabling KVM support.")
 802
 803 # Check if the TUN/TAP driver is available.
 804 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 805 if not have_tuntap:
 806     print("Info: Compatible header file <linux/if_tun.h> not found.")
 807
 808 # x86 needs support for xsave. We test for the structure here since we
 809 # won't be able to run new tests by the time we know which ISA we're
 810 # targeting.
 811 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 812                                     '#include <linux/kvm.h>') != 0
 813
 814 # Check if the requested target ISA is compatible with the host
 815 def is_isa_kvm_compatible(isa):
 816     try:
 817         import platform
 818         host_isa = platform.machine()
 819     except:
 820         warning("Failed to determine host ISA.")
 821         return False
 822
 823     if not have_posix_timers:
 824         warning("Can not enable KVM, host seems to lack support "
 825                 "for POSIX timers")
 826         return False
 827
 828     if isa == "arm":
 829         return host_isa in ( "armv7l", "aarch64" )
 830     elif isa == "x86":
 831         if host_isa != "x86_64":
 832             return False
 833
 834         if not have_kvm_xsave:
 835             warning("KVM on x86 requires xsave support in kernel headers.")
 836             return False
 837
 838         return True
 839     else:
 840         return False
 841
 842
 843 # Check if the exclude_host attribute is available. We want this to
 844 # get accurate instruction counts in KVM.
 845 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 846     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 847
 848 def check_hdf5():
 849     return \
 850         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 851                                 'H5Fcreate("", 0, 0, 0);') and \
 852         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 853                                 'H5::H5File("", 0);')
 854
 855 def check_hdf5_pkg(name):
 856     print("Checking for %s using pkg-config..." % name, end="")
 857     if not have_pkg_config:
 858         print(" pkg-config not found")
 859         return False
 860
 861     try:
 862         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 863         print(" yes")
 864         return True
 865     except:
 866         print(" no")
 867         return False
 868
 869 # Check if there is a pkg-config configuration for hdf5. If we find
 870 # it, setup the environment to enable linking and header inclusion. We
 871 # don't actually try to include any headers or link with hdf5 at this
 872 # stage.
 873 if not check_hdf5_pkg('hdf5-serial'):
 874     check_hdf5_pkg('hdf5')
 875
 876 # Check if the HDF5 libraries can be found. This check respects the
 877 # include path and library path provided by pkg-config. We perform
 878 # this check even if there isn't a pkg-config configuration for hdf5
 879 # since some installations don't use pkg-config.
 880 have_hdf5 = check_hdf5()
 881 if not have_hdf5:
 882     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 883     print("         HDF5 support.")
 884
 885 ######################################################################
 886 #
 887 # Finish the configuration
 888 #
 889 main = conf.Finish()
 890
 891 ######################################################################
 892 #
 893 # Collect all non-global variables
 894 #
 895
 896 # Define the universe of supported ISAs
 897 all_isa_list = [ ]
 898 all_gpu_isa_list = [ ]
 899 Export('all_isa_list')
 900 Export('all_gpu_isa_list')
 901
 902 class CpuModel(object):
 903     '''The CpuModel class encapsulates everything the ISA parser needs to
 904     know about a particular CPU model.'''
 905
 906     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 907     dict = {}
 908
 909     # Constructor.  Automatically adds models to CpuModel.dict.
 910     def __init__(self, name, default=False):
 911         self.name = name           # name of model
 912
 913         # This cpu is enabled by default
 914         self.default = default
 915
 916         # Add self to dict
 917         if name in CpuModel.dict:
 918             raise AttributeError("CpuModel '%s' already registered" % name)
 919         CpuModel.dict[name] = self
 920
 921 Export('CpuModel')
 922
 923 # Sticky variables get saved in the variables file so they persist from
 924 # one invocation to the next (unless overridden, in which case the new
 925 # value becomes sticky).
 926 sticky_vars = Variables(args=ARGUMENTS)
 927 Export('sticky_vars')
 928
 929 # Sticky variables that should be exported
 930 export_vars = []
 931 Export('export_vars')
 932
 933 # For Ruby
 934 all_protocols = []
 935 Export('all_protocols')
 936 protocol_dirs = []
 937 Export('protocol_dirs')
 938 slicc_includes = []
 939 Export('slicc_includes')
 940
 941 # Walk the tree and execute all SConsopts scripts that wil add to the
 942 # above variables
 943 if GetOption('verbose'):
 944     print("Reading SConsopts")
 945 for bdir in [ base_dir ] + extras_dir_list:
 946     if not isdir(bdir):
 947         error("Directory '%s' does not exist." % bdir)
 948     for root, dirs, files in os.walk(bdir):
 949         if 'SConsopts' in files:
 950             if GetOption('verbose'):
 951                 print("Reading", joinpath(root, 'SConsopts'))
 952             SConscript(joinpath(root, 'SConsopts'))
 953
 954 all_isa_list.sort()
 955 all_gpu_isa_list.sort()
 956
 957 sticky_vars.AddVariables(
 958     EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list),
 959     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'gcn3', all_gpu_isa_list),
 960     ListVariable('CPU_MODELS', 'CPU models',
 961                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 962                  sorted(CpuModel.dict.keys())),
 963     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 964                  False),
 965     BoolVariable('USE_SSE2',
 966                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 967                  False),
 968     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 969     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 970     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 971     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 972                  have_kvm),
 973     BoolVariable('USE_TUNTAP',
 974                  'Enable using a tap device to bridge to the host network',
 975                  have_tuntap),
 976     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
 977     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
 978                   all_protocols),
 979     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
 980                  backtrace_impls[-1], backtrace_impls),
 981     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
 982                  64),
 983     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
 984     )
 985
 986 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 987 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA',
 988                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
 989                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
 990                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
 991                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
 992
 993 ###################################################
 994 #
 995 # Define a SCons builder for configuration flag headers.
 996 #
 997 ###################################################
 998
 999 # This function generates a config header file that #defines the
1000 # variable symbol to the current variable setting (0 or 1).  The source
1001 # operands are the name of the variable and a Value node containing the
1002 # value of the variable.
1003 def build_config_file(target, source, env):
1004     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
1005     with open(str(target[0]), 'w') as f:
1006         print('#define', variable, value, file=f)
1007     return None
1008
1009 # Combine the two functions into a scons Action object.
1010 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1011
1012 # The emitter munges the source & target node lists to reflect what
1013 # we're really doing.
1014 def config_emitter(target, source, env):
1015     # extract variable name from Builder arg
1016     variable = str(target[0])
1017     # True target is config header file
1018     target = joinpath('config', variable.lower() + '.hh')
1019     val = env[variable]
1020     if isinstance(val, bool):
1021         # Force value to 0/1
1022         val = int(val)
1023     elif isinstance(val, str):
1024         val = '"' + val + '"'
1025
1026     # Sources are variable name & value (packaged in SCons Value nodes)
1027     return ([target], [Value(variable), Value(val)])
1028
1029 config_builder = Builder(emitter = config_emitter, action = config_action)
1030
1031 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1032
1033 ###################################################
1034 #
1035 # Builders for static and shared partially linked object files.
1036 #
1037 ###################################################
1038
1039 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1040                                  src_suffix='$OBJSUFFIX',
1041                                  src_builder=['StaticObject', 'Object'],
1042                                  LINKFLAGS='$PLINKFLAGS',
1043                                  LIBS='')
1044
1045 def partial_shared_emitter(target, source, env):
1046     for tgt in target:
1047         tgt.attributes.shared = 1
1048     return (target, source)
1049 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1050                                  emitter=partial_shared_emitter,
1051                                  src_suffix='$SHOBJSUFFIX',
1052                                  src_builder='SharedObject',
1053                                  SHLINKFLAGS='$PSHLINKFLAGS',
1054                                  LIBS='')
1055
1056 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1057                          'PartialStatic' : partial_static_builder })
1058
1059 def add_local_rpath(env, *targets):
1060     '''Set up an RPATH for a library which lives in the build directory.
1061
1062     The construction environment variable BIN_RPATH_PREFIX should be set to
1063     the relative path of the build directory starting from the location of the
1064     binary.'''
1065     for target in targets:
1066         target = env.Entry(target)
1067         if not isinstance(target, SCons.Node.FS.Dir):
1068             target = target.dir
1069         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1070         components = [
1071             '\\$$ORIGIN',
1072             '${BIN_RPATH_PREFIX}',
1073             relpath
1074         ]
1075         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1076
1077 if sys.platform != "darwin":
1078     main.Append(LINKFLAGS=Split('-z origin'))
1079
1080 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1081
1082 # builds in ext are shared across all configs in the build root.
1083 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1084 ext_build_dirs = []
1085 for root, dirs, files in os.walk(ext_dir):
1086     if 'SConscript' in files:
1087         build_dir = os.path.relpath(root, ext_dir)
1088         ext_build_dirs.append(build_dir)
1089         main.SConscript(joinpath(root, 'SConscript'),
1090                         variant_dir=joinpath(build_root, build_dir))
1091
1092 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1093 Export('gdb_xml_dir')
1094
1095 ###################################################
1096 #
1097 # This builder and wrapper method are used to set up a directory with
1098 # switching headers. Those are headers which are in a generic location and
1099 # that include more specific headers from a directory chosen at build time
1100 # based on the current build settings.
1101 #
1102 ###################################################
1103
1104 def build_switching_header(target, source, env):
1105     path = str(target[0])
1106     subdir = str(source[0])
1107     dp, fp = os.path.split(path)
1108     dp = os.path.relpath(os.path.realpath(dp),
1109                          os.path.realpath(env['BUILDDIR']))
1110     with open(path, 'w') as hdr:
1111         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1112
1113 switching_header_action = MakeAction(build_switching_header,
1114                                      Transform('GENERATE'))
1115
1116 switching_header_builder = Builder(action=switching_header_action,
1117                                    source_factory=Value,
1118                                    single_source=True)
1119
1120 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1121
1122 def switching_headers(self, headers, source):
1123     for header in headers:
1124         self.SwitchingHeader(header, source)
1125
1126 main.AddMethod(switching_headers, 'SwitchingHeaders')
1127
1128 ###################################################
1129 #
1130 # Define build environments for selected configurations.
1131 #
1132 ###################################################
1133
1134 for variant_path in variant_paths:
1135     if not GetOption('silent'):
1136         print("Building in", variant_path)
1137
1138     # Make a copy of the build-root environment to use for this config.
1139     env = main.Clone()
1140     env['BUILDDIR'] = variant_path
1141
1142     # variant_dir is the tail component of build path, and is used to
1143     # determine the build parameters (e.g., 'X86')
1144     (build_root, variant_dir) = splitpath(variant_path)
1145
1146     # Set env variables according to the build directory config.
1147     sticky_vars.files = []
1148     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1149     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1150     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1151     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1152     if isfile(current_vars_file):
1153         sticky_vars.files.append(current_vars_file)
1154         if not GetOption('silent'):
1155             print("Using saved variables file %s" % current_vars_file)
1156     elif variant_dir in ext_build_dirs:
1157         # Things in ext are built without a variant directory.
1158         continue
1159     else:
1160         # Build dir-specific variables file doesn't exist.
1161
1162         # Make sure the directory is there so we can create it later
1163         opt_dir = dirname(current_vars_file)
1164         if not isdir(opt_dir):
1165             mkdir(opt_dir)
1166
1167         # Get default build variables from source tree.  Variables are
1168         # normally determined by name of $VARIANT_DIR, but can be
1169         # overridden by '--default=' arg on command line.
1170         default = GetOption('default')
1171         opts_dir = joinpath(main.root.abspath, 'build_opts')
1172         if default:
1173             default_vars_files = [joinpath(build_root, 'variables', default),
1174                                   joinpath(opts_dir, default)]
1175         else:
1176             default_vars_files = [joinpath(opts_dir, variant_dir)]
1177         existing_files = list(filter(isfile, default_vars_files))
1178         if existing_files:
1179             default_vars_file = existing_files[0]
1180             sticky_vars.files.append(default_vars_file)
1181             print("Variables file %s not found,\n  using defaults in %s"
1182                   % (current_vars_file, default_vars_file))
1183         else:
1184             error("Cannot find variables file %s or default file(s) %s"
1185                   % (current_vars_file, ' or '.join(default_vars_files)))
1186             Exit(1)
1187
1188     # Apply current variable settings to env
1189     sticky_vars.Update(env)
1190
1191     Help('''
1192 Build variables for {dir}:
1193 {help}
1194 '''.format(dir=variant_dir, help=sticky_vars.GenerateHelpText(env)),
1195          append=True)
1196
1197     # Process variable settings.
1198
1199     if not have_fenv and env['USE_FENV']:
1200         warning("<fenv.h> not available; forcing USE_FENV to False in",
1201                 variant_dir + ".")
1202         env['USE_FENV'] = False
1203
1204     if not env['USE_FENV']:
1205         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1206                 "FP results may deviate slightly from other platforms.")
1207
1208     if not have_png and env['USE_PNG']:
1209         warning("<png.h> not available; forcing USE_PNG to False in",
1210                 variant_dir + ".")
1211         env['USE_PNG'] = False
1212
1213     if env['USE_PNG']:
1214         env.Append(LIBS=['png'])
1215
1216     if env['EFENCE']:
1217         env.Append(LIBS=['efence'])
1218
1219     if env['USE_KVM']:
1220         if not have_kvm:
1221             warning("Can not enable KVM, host seems to lack KVM support")
1222             env['USE_KVM'] = False
1223         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1224             print("Info: KVM support disabled due to unsupported host and "
1225                   "target ISA combination")
1226             env['USE_KVM'] = False
1227
1228     if env['USE_TUNTAP']:
1229         if not have_tuntap:
1230             warning("Can't connect EtherTap with a tap device.")
1231             env['USE_TUNTAP'] = False
1232
1233     if env['BUILD_GPU']:
1234         env.Append(CPPDEFINES=['BUILD_GPU'])
1235
1236     # Warn about missing optional functionality
1237     if env['USE_KVM']:
1238         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1239             warning("perf_event headers lack support for the exclude_host "
1240                     "attribute. KVM instruction counts will be inaccurate.")
1241
1242     # Save sticky variable settings back to current variables file
1243     sticky_vars.Save(current_vars_file, env)
1244
1245     if env['USE_SSE2']:
1246         env.Append(CCFLAGS=['-msse2'])
1247
1248     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1249     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1250
1251     # The src/SConscript file sets up the build rules in 'env' according
1252     # to the configured variables.  It returns a list of environments,
1253     # one for each variant build (debug, opt, etc.)
1254     SConscript('src/SConscript', variant_dir=variant_path,
1255                exports=['env', 'marshal_env'])
1256
1257 atexit.register(summarize_warnings)