SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2013, 2015-2020 ARM Limited
   4 # All rights reserved.
   5 #
   6 # The license below extends only to copyright in the software and shall
   7 # not be construed as granting a license to any other intellectual
   8 # property including but not limited to intellectual property relating
   9 # to a hardware implementation of the functionality of the software
  10 # licensed hereunder.  You may use the software subject to the license
  11 # terms below provided that you ensure that this notice is replicated
  12 # unmodified and in its entirety in all distributions of the software,
  13 # modified or unmodified, in source code or in binary form.
  14 #
  15 # Copyright (c) 2011 Advanced Micro Devices, Inc.
  16 # Copyright (c) 2009 The Hewlett-Packard Development Company
  17 # Copyright (c) 2004-2005 The Regents of The University of Michigan
  18 # All rights reserved.
  19 #
  20 # Redistribution and use in source and binary forms, with or without
  21 # modification, are permitted provided that the following conditions are
  22 # met: redistributions of source code must retain the above copyright
  23 # notice, this list of conditions and the following disclaimer;
  24 # redistributions in binary form must reproduce the above copyright
  25 # notice, this list of conditions and the following disclaimer in the
  26 # documentation and/or other materials provided with the distribution;
  27 # neither the name of the copyright holders nor the names of its
  28 # contributors may be used to endorse or promote products derived from
  29 # this software without specific prior written permission.
  30 #
  31 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  34 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  37 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  41 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42
  43 ###################################################
  44 #
  45 # SCons top-level build description (SConstruct) file.
  46 #
  47 # While in this directory ('gem5'), just type 'scons' to build the default
  48 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
  49 # to build some other configuration (e.g., 'build/X86/gem5.opt' for
  50 # the optimized full-system version).
  51 #
  52 # You can build gem5 in a different directory as long as there is a
  53 # 'build/<CONFIG>' somewhere along the target path.  The build system
  54 # expects that all configs under the same build directory are being
  55 # built for the same host system.
  56 #
  57 # Examples:
  58 #
  59 #   The following two commands are equivalent.  The '-u' option tells
  60 #   scons to search up the directory tree for this SConstruct file.
  61 #   % cd <path-to-src>/gem5 ; scons build/X86/gem5.debug
  62 #   % cd <path-to-src>/gem5/build/X86; scons -u gem5.debug
  63 #
  64 #   The following two commands are equivalent and demonstrate building
  65 #   in a directory outside of the source tree.  The '-C' option tells
  66 #   scons to chdir to the specified directory to find this SConstruct
  67 #   file.
  68 #   % cd <path-to-src>/gem5 ; scons /local/foo/build/X86/gem5.debug
  69 #   % cd /local/foo/build/X86; scons -C <path-to-src>/gem5 gem5.debug
  70 #
  71 # You can use 'scons -H' to print scons options.  If you're in this
  72 # 'gem5' directory (or use -u or -C to tell scons where to find this
  73 # file), you can use 'scons -h' to print all the gem5-specific build
  74 # options as well.
  75 #
  76 ###################################################
  77
  78 from __future__ import print_function
  79
  80 # Global Python includes
  81 import atexit
  82 import itertools
  83 import os
  84 import re
  85 import shutil
  86 import subprocess
  87 import sys
  88
  89 from os import mkdir, environ
  90 from os.path import abspath, basename, dirname, expanduser, normpath
  91 from os.path import exists,  isdir, isfile
  92 from os.path import join as joinpath, split as splitpath
  93 from re import match
  94
  95 # SCons includes
  96 import SCons
  97 import SCons.Node
  98 import SCons.Node.FS
  99
 100 from m5.util import compareVersions, readCommand, readCommandWithReturn
 101
 102 help_texts = {
 103     "options" : "",
 104     "global_vars" : "",
 105     "local_vars" : ""
 106 }
 107
 108 Export("help_texts")
 109
 110
 111 # There's a bug in scons in that (1) by default, the help texts from
 112 # AddOption() are supposed to be displayed when you type 'scons -h'
 113 # and (2) you can override the help displayed by 'scons -h' using the
 114 # Help() function, but these two features are incompatible: once
 115 # you've overridden the help text using Help(), there's no way to get
 116 # at the help texts from AddOptions.  See:
 117 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 118 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 119 # This hack lets us extract the help text from AddOptions and
 120 # re-inject it via Help().  Ideally someday this bug will be fixed and
 121 # we can just use AddOption directly.
 122 def AddLocalOption(*args, **kwargs):
 123     col_width = 30
 124
 125     help = "  " + ", ".join(args)
 126     if "help" in kwargs:
 127         length = len(help)
 128         if length >= col_width:
 129             help += "\n" + " " * col_width
 130         else:
 131             help += " " * (col_width - length)
 132         help += kwargs["help"]
 133     help_texts["options"] += help + "\n"
 134
 135     AddOption(*args, **kwargs)
 136
 137 AddLocalOption('--colors', dest='use_colors', action='store_true',
 138                help="Add color to abbreviated scons output")
 139 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 140                help="Don't add color to abbreviated scons output")
 141 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 142                action='store_true',
 143                help="Build with support for C++-based configuration")
 144 AddLocalOption('--default', dest='default', type='string', action='store',
 145                help='Override which build_opts file to use for defaults')
 146 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 147                help='Disable style checking hooks')
 148 AddLocalOption('--gold-linker', dest='gold_linker', action='store_true',
 149                help='Use the gold linker')
 150 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 151                help='Disable Link-Time Optimization for fast')
 152 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 153                help='Use Link-Time Optimization instead of partial linking' +
 154                     ' when the compiler doesn\'t support using them together.')
 155 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 156                help='Update test reference outputs')
 157 AddLocalOption('--verbose', dest='verbose', action='store_true',
 158                help='Print full tool command lines')
 159 AddLocalOption('--without-python', dest='without_python',
 160                action='store_true',
 161                help='Build without Python configuration support')
 162 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 163                action='store_true',
 164                help='Disable linking against tcmalloc')
 165 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 166                help='Build with Undefined Behavior Sanitizer if available')
 167 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 168                help='Build with Address Sanitizer if available')
 169 AddLocalOption('--with-systemc-tests', dest='with_systemc_tests',
 170                action='store_true', help='Build systemc tests')
 171
 172 from gem5_scons import Transform, error, warning, summarize_warnings
 173
 174 if GetOption('no_lto') and GetOption('force_lto'):
 175     error('--no-lto and --force-lto are mutually exclusive')
 176
 177 ########################################################################
 178 #
 179 # Set up the main build environment.
 180 #
 181 ########################################################################
 182
 183 main = Environment()
 184
 185 from gem5_scons.util import get_termcap
 186 termcap = get_termcap()
 187
 188 main_dict_keys = main.Dictionary().keys()
 189
 190 # Check that we have a C/C++ compiler
 191 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 192     error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 193
 194 ###################################################
 195 #
 196 # Figure out which configurations to set up based on the path(s) of
 197 # the target(s).
 198 #
 199 ###################################################
 200
 201 # Find default configuration & binary.
 202 Default(environ.get('M5_DEFAULT_BINARY', 'build/ARM/gem5.debug'))
 203
 204 # helper function: find last occurrence of element in list
 205 def rfind(l, elt, offs = -1):
 206     for i in range(len(l)+offs, 0, -1):
 207         if l[i] == elt:
 208             return i
 209     raise ValueError("element not found")
 210
 211 # Take a list of paths (or SCons Nodes) and return a list with all
 212 # paths made absolute and ~-expanded.  Paths will be interpreted
 213 # relative to the launch directory unless a different root is provided
 214 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 215     return [abspath(joinpath(root, expanduser(str(p))))
 216             for p in path_list]
 217
 218 # Each target must have 'build' in the interior of the path; the
 219 # directory below this will determine the build parameters.  For
 220 # example, for target 'foo/bar/build/X86/arch/x86/blah.do' we
 221 # recognize that X86 specifies the configuration because it
 222 # follow 'build' in the build path.
 223
 224 # The funky assignment to "[:]" is needed to replace the list contents
 225 # in place rather than reassign the symbol to a new list, which
 226 # doesn't work (obviously!).
 227 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 228
 229 # Generate a list of the unique build roots and configs that the
 230 # collected targets reference.
 231 variant_paths = []
 232 build_root = None
 233 for t in BUILD_TARGETS:
 234     path_dirs = t.split('/')
 235     try:
 236         build_top = rfind(path_dirs, 'build', -2)
 237     except:
 238         error("No non-leaf 'build' dir found on target path.", t)
 239     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 240     if not build_root:
 241         build_root = this_build_root
 242     else:
 243         if this_build_root != build_root:
 244             error("build targets not under same build root\n"
 245                   "  %s\n  %s" % (build_root, this_build_root))
 246     variant_path = joinpath('/',*path_dirs[:build_top+2])
 247     if variant_path not in variant_paths:
 248         variant_paths.append(variant_path)
 249
 250 # Make sure build_root exists (might not if this is the first build there)
 251 if not isdir(build_root):
 252     mkdir(build_root)
 253 main['BUILDROOT'] = build_root
 254
 255 Export('main')
 256
 257 main.SConsignFile(joinpath(build_root, "sconsign"))
 258
 259 # Default duplicate option is to use hard links, but this messes up
 260 # when you use emacs to edit a file in the target dir, as emacs moves
 261 # file to file~ then copies to file, breaking the link.  Symbolic
 262 # (soft) links work better.
 263 main.SetOption('duplicate', 'soft-copy')
 264
 265 #
 266 # Set up global sticky variables... these are common to an entire build
 267 # tree (not specific to a particular build like X86)
 268 #
 269
 270 global_vars_file = joinpath(build_root, 'variables.global')
 271
 272 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 273
 274 global_vars.AddVariables(
 275     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 276     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 277     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 278     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 279     ('MARSHAL_CCFLAGS_EXTRA', 'Extra C and C++ marshal compiler flags', ''),
 280     ('MARSHAL_LDFLAGS_EXTRA', 'Extra marshal linker flags', ''),
 281     ('PYTHON_CONFIG', 'Python config binary to use',
 282      [ 'python2.7-config', 'python-config', 'python3-config' ]),
 283     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 284     ('BATCH', 'Use batch pool for build and tests', False),
 285     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 286     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 287     ('EXTRAS', 'Add extra directories to the compilation', '')
 288     )
 289
 290 # Update main environment with values from ARGUMENTS & global_vars_file
 291 global_vars.Update(main)
 292 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 293
 294 # Save sticky variable settings back to current variables file
 295 global_vars.Save(global_vars_file, main)
 296
 297 # Parse EXTRAS variable to build list of all directories where we're
 298 # look for sources etc.  This list is exported as extras_dir_list.
 299 base_dir = main.srcdir.abspath
 300 if main['EXTRAS']:
 301     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 302 else:
 303     extras_dir_list = []
 304
 305 Export('base_dir')
 306 Export('extras_dir_list')
 307
 308 # the ext directory should be on the #includes path
 309 main.Append(CPPPATH=[Dir('ext')])
 310
 311 # Add shared top-level headers
 312 main.Prepend(CPPPATH=Dir('include'))
 313
 314 if GetOption('verbose'):
 315     def MakeAction(action, string, *args, **kwargs):
 316         return Action(action, *args, **kwargs)
 317 else:
 318     MakeAction = Action
 319     main['CCCOMSTR']        = Transform("CC")
 320     main['CXXCOMSTR']       = Transform("CXX")
 321     main['ASCOMSTR']        = Transform("AS")
 322     main['ARCOMSTR']        = Transform("AR", 0)
 323     main['LINKCOMSTR']      = Transform("LINK", 0)
 324     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 325     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 326     main['M4COMSTR']        = Transform("M4")
 327     main['SHCCCOMSTR']      = Transform("SHCC")
 328     main['SHCXXCOMSTR']     = Transform("SHCXX")
 329 Export('MakeAction')
 330
 331 # Initialize the Link-Time Optimization (LTO) flags
 332 main['LTO_CCFLAGS'] = []
 333 main['LTO_LDFLAGS'] = []
 334
 335 # According to the readme, tcmalloc works best if the compiler doesn't
 336 # assume that we're using the builtin malloc and friends. These flags
 337 # are compiler-specific, so we need to set them after we detect which
 338 # compiler we're using.
 339 main['TCMALLOC_CCFLAGS'] = []
 340
 341 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 342 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 343
 344 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 345 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 346 if main['GCC'] + main['CLANG'] > 1:
 347     error('Two compilers enabled at once?')
 348
 349 # Set up default C++ compiler flags
 350 if main['GCC'] or main['CLANG']:
 351     # As gcc and clang share many flags, do the common parts here
 352     main.Append(CCFLAGS=['-pipe'])
 353     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 354     # Enable -Wall and -Wextra and then disable the few warnings that
 355     # we consistently violate
 356     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 357                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 358     # We always compile using C++11
 359     main.Append(CXXFLAGS=['-std=c++11'])
 360     if sys.platform.startswith('freebsd'):
 361         main.Append(CCFLAGS=['-I/usr/local/include'])
 362         main.Append(CXXFLAGS=['-I/usr/local/include'])
 363
 364     # On Mac OS X/Darwin the default linker doesn't support the
 365     # option --as-needed
 366     if sys.platform != "darwin":
 367         main.Append(LINKFLAGS='-Wl,--as-needed')
 368     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 369     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 370     if GetOption('gold_linker'):
 371         main.Append(LINKFLAGS='-fuse-ld=gold')
 372     main['PLINKFLAGS'] = main.get('LINKFLAGS')
 373     shared_partial_flags = ['-r', '-nostdlib']
 374     main.Append(PSHLINKFLAGS=shared_partial_flags)
 375     main.Append(PLINKFLAGS=shared_partial_flags)
 376
 377     # Treat warnings as errors but white list some warnings that we
 378     # want to allow (e.g., deprecation warnings).
 379     main.Append(CCFLAGS=['-Werror',
 380                          '-Wno-error=deprecated-declarations',
 381                          '-Wno-error=deprecated',
 382                         ])
 383 else:
 384     error('\n'.join((
 385           "Don't know what compiler options to use for your compiler.",
 386           "compiler: " + main['CXX'],
 387           "version: " + CXX_version.replace('\n', '<nl>') if
 388                 CXX_version else 'COMMAND NOT FOUND!',
 389           "If you're trying to use a compiler other than GCC",
 390           "or clang, there appears to be something wrong with your",
 391           "environment.",
 392           "",
 393           "If you are trying to use a compiler other than those listed",
 394           "above you will need to ease fix SConstruct and ",
 395           "src/SConscript to support that compiler.")))
 396
 397 if main['GCC']:
 398     # Check for a supported version of gcc. >= 4.8 is chosen for its
 399     # level of c++11 support. See
 400     # http://gcc.gnu.org/projects/cxx0x.html for details.
 401     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 402     if compareVersions(gcc_version, "4.8") < 0:
 403         error('gcc version 4.8 or newer required.\n'
 404               'Installed version:', gcc_version)
 405         Exit(1)
 406
 407     main['GCC_VERSION'] = gcc_version
 408
 409     if compareVersions(gcc_version, '4.9') >= 0:
 410         # Incremental linking with LTO is currently broken in gcc versions
 411         # 4.9 and above. A version where everything works completely hasn't
 412         # yet been identified.
 413         #
 414         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 415         main['BROKEN_INCREMENTAL_LTO'] = True
 416     if compareVersions(gcc_version, '6.0') >= 0:
 417         # gcc versions 6.0 and greater accept an -flinker-output flag which
 418         # selects what type of output the linker should generate. This is
 419         # necessary for incremental lto to work, but is also broken in
 420         # current versions of gcc. It may not be necessary in future
 421         # versions. We add it here since it might be, and as a reminder that
 422         # it exists. It's excluded if lto is being forced.
 423         #
 424         # https://gcc.gnu.org/gcc-6/changes.html
 425         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 426         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 427         if not GetOption('force_lto'):
 428             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 429             main.Append(PLINKFLAGS='-flinker-output=rel')
 430
 431     disable_lto = GetOption('no_lto')
 432     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 433             not GetOption('force_lto'):
 434         warning('Your compiler doesn\'t support incremental linking and lto '
 435                 'at the same time, so lto is being disabled. To force lto on '
 436                 'anyway, use the --force-lto option. That will disable '
 437                 'partial linking.')
 438         disable_lto = True
 439
 440     # Add the appropriate Link-Time Optimization (LTO) flags
 441     # unless LTO is explicitly turned off. Note that these flags
 442     # are only used by the fast target.
 443     if not disable_lto:
 444         # Pass the LTO flag when compiling to produce GIMPLE
 445         # output, we merely create the flags here and only append
 446         # them later
 447         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 448
 449         # Use the same amount of jobs for LTO as we are running
 450         # scons with
 451         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 452
 453     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 454                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 455
 456 elif main['CLANG']:
 457     # Check for a supported version of clang, >= 3.1 is needed to
 458     # support similar features as gcc 4.8. See
 459     # http://clang.llvm.org/cxx_status.html for details
 460     clang_version_re = re.compile(".* version (\d+\.\d+)")
 461     clang_version_match = clang_version_re.search(CXX_version)
 462     if (clang_version_match):
 463         clang_version = clang_version_match.groups()[0]
 464         if compareVersions(clang_version, "3.1") < 0:
 465             error('clang version 3.1 or newer required.\n'
 466                   'Installed version:', clang_version)
 467     else:
 468         error('Unable to determine clang version.')
 469
 470     # clang has a few additional warnings that we disable, extraneous
 471     # parantheses are allowed due to Ruby's printing of the AST,
 472     # finally self assignments are allowed as the generated CPU code
 473     # is relying on this
 474     main.Append(CCFLAGS=['-Wno-parentheses',
 475                          '-Wno-self-assign',
 476                          # Some versions of libstdc++ (4.8?) seem to
 477                          # use struct hash and class hash
 478                          # interchangeably.
 479                          '-Wno-mismatched-tags',
 480                          ])
 481     if compareVersions(clang_version, "10.0") >= 0:
 482         main.Append(CCFLAGS=['-Wno-c99-designator'])
 483
 484     if compareVersions(clang_version, "8.0") >= 0:
 485         main.Append(CCFLAGS=['-Wno-defaulted-function-deleted'])
 486
 487     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 488
 489     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 490     # opposed to libstdc++, as the later is dated.
 491     if sys.platform == "darwin":
 492         main.Append(CXXFLAGS=['-stdlib=libc++'])
 493         main.Append(LIBS=['c++'])
 494
 495     # On FreeBSD we need libthr.
 496     if sys.platform.startswith('freebsd'):
 497         main.Append(LIBS=['thr'])
 498
 499 # Add sanitizers flags
 500 sanitizers=[]
 501 if GetOption('with_ubsan'):
 502     # Only gcc >= 4.9 supports UBSan, so check both the version
 503     # and the command-line option before adding the compiler and
 504     # linker flags.
 505     if not main['GCC'] or compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 506         sanitizers.append('undefined')
 507 if GetOption('with_asan'):
 508     # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
 509     # by the build system
 510     sanitizers.append('address')
 511     suppressions_file = Dir('util').File('lsan-suppressions').get_abspath()
 512     suppressions_opt = 'suppressions=%s' % suppressions_file
 513     main['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt,
 514                                             'print_suppressions=0'])
 515     print()
 516     warning('To suppress false positive leaks, set the LSAN_OPTIONS '
 517             'environment variable to "%s" when running gem5' %
 518             suppressions_opt)
 519     warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt)
 520     print()
 521 if sanitizers:
 522     sanitizers = ','.join(sanitizers)
 523     if main['GCC'] or main['CLANG']:
 524         main.Append(CCFLAGS=['-fsanitize=%s' % sanitizers,
 525                              '-fno-omit-frame-pointer'],
 526                     LINKFLAGS='-fsanitize=%s' % sanitizers)
 527     else:
 528         warning("Don't know how to enable %s sanitizer(s) for your "
 529                 "compiler." % sanitizers)
 530
 531 # Set up common yacc/bison flags (needed for Ruby)
 532 main['YACCFLAGS'] = '-d'
 533 main['YACCHXXFILESUFFIX'] = '.hh'
 534
 535 # Do this after we save setting back, or else we'll tack on an
 536 # extra 'qdo' every time we run scons.
 537 if main['BATCH']:
 538     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 539     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 540     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 541     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 542     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 543
 544 if sys.platform == 'cygwin':
 545     # cygwin has some header file issues...
 546     main.Append(CCFLAGS=["-Wno-uninitialized"])
 547
 548
 549 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 550
 551 # Check for the protobuf compiler
 552 try:
 553     main['HAVE_PROTOC'] = True
 554     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 555
 556     # First two words should be "libprotoc x.y.z"
 557     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 558         warning('Protocol buffer compiler (protoc) not found.\n'
 559                 'Please install protobuf-compiler for tracing support.')
 560         main['HAVE_PROTOC'] = False
 561     else:
 562         # Based on the availability of the compress stream wrappers,
 563         # require 2.1.0
 564         min_protoc_version = '2.1.0'
 565         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 566             warning('protoc version', min_protoc_version,
 567                     'or newer required.\n'
 568                     'Installed version:', protoc_version[1])
 569             main['HAVE_PROTOC'] = False
 570         else:
 571             # Attempt to determine the appropriate include path and
 572             # library path using pkg-config, that means we also need to
 573             # check for pkg-config. Note that it is possible to use
 574             # protobuf without the involvement of pkg-config. Later on we
 575             # check go a library config check and at that point the test
 576             # will fail if libprotobuf cannot be found.
 577             if have_pkg_config:
 578                 try:
 579                     # Attempt to establish what linking flags to add for
 580                     # protobuf
 581                     # using pkg-config
 582                     main.ParseConfig(
 583                             'pkg-config --cflags --libs-only-L protobuf')
 584                 except:
 585                     warning('pkg-config could not get protobuf flags.')
 586 except Exception as e:
 587     warning('While checking protoc version:', str(e))
 588     main['HAVE_PROTOC'] = False
 589
 590 # Check for 'timeout' from GNU coreutils. If present, regressions will
 591 # be run with a time limit. We require version 8.13 since we rely on
 592 # support for the '--foreground' option.
 593 if sys.platform.startswith('freebsd'):
 594     timeout_lines = readCommand(['gtimeout', '--version'],
 595                                 exception='').splitlines()
 596 else:
 597     timeout_lines = readCommand(['timeout', '--version'],
 598                                 exception='').splitlines()
 599 # Get the first line and tokenize it
 600 timeout_version = timeout_lines[0].split() if timeout_lines else []
 601 main['TIMEOUT'] =  timeout_version and \
 602     compareVersions(timeout_version[-1], '8.13') >= 0
 603
 604 # Add a custom Check function to test for structure members.
 605 def CheckMember(context, include, decl, member, include_quotes="<>"):
 606     context.Message("Checking for member %s in %s..." %
 607                     (member, decl))
 608     text = """
 609 #include %(header)s
 610 int main(){
 611   %(decl)s test;
 612   (void)test.%(member)s;
 613   return 0;
 614 };
 615 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 616         "decl" : decl,
 617         "member" : member,
 618         }
 619
 620     ret = context.TryCompile(text, extension=".cc")
 621     context.Result(ret)
 622     return ret
 623
 624 # Platform-specific configuration.  Note again that we assume that all
 625 # builds under a given build root run on the same host platform.
 626 conf = Configure(main,
 627                  conf_dir = joinpath(build_root, '.scons_config'),
 628                  log_file = joinpath(build_root, 'scons_config.log'),
 629                  custom_tests = {
 630         'CheckMember' : CheckMember,
 631         })
 632
 633 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 634 try:
 635     import platform
 636     uname = platform.uname()
 637     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 638         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 639             main.Append(CCFLAGS=['-arch', 'x86_64'])
 640             main.Append(CFLAGS=['-arch', 'x86_64'])
 641             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 642             main.Append(ASFLAGS=['-arch', 'x86_64'])
 643 except:
 644     pass
 645
 646 # Recent versions of scons substitute a "Null" object for Configure()
 647 # when configuration isn't necessary, e.g., if the "--help" option is
 648 # present.  Unfortuantely this Null object always returns false,
 649 # breaking all our configuration checks.  We replace it with our own
 650 # more optimistic null object that returns True instead.
 651 if not conf:
 652     def NullCheck(*args, **kwargs):
 653         return True
 654
 655     class NullConf:
 656         def __init__(self, env):
 657             self.env = env
 658         def Finish(self):
 659             return self.env
 660         def __getattr__(self, mname):
 661             return NullCheck
 662
 663     conf = NullConf(main)
 664
 665 # Cache build files in the supplied directory.
 666 if main['M5_BUILD_CACHE']:
 667     print('Using build cache located at', main['M5_BUILD_CACHE'])
 668     CacheDir(main['M5_BUILD_CACHE'])
 669
 670 main['USE_PYTHON'] = not GetOption('without_python')
 671 if main['USE_PYTHON']:
 672     # Find Python include and library directories for embedding the
 673     # interpreter. We rely on python-config to resolve the appropriate
 674     # includes and linker flags. ParseConfig does not seem to understand
 675     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 676     # we add them explicitly below. If you want to link in an alternate
 677     # version of python, see above for instructions on how to invoke
 678     # scons with the appropriate PATH set.
 679
 680     python_config = main.Detect(main['PYTHON_CONFIG'])
 681     if python_config is None:
 682         error("Can't find a suitable python-config, tried %s" % \
 683               main['PYTHON_CONFIG'])
 684
 685     print("Info: Using Python config: %s" % (python_config, ))
 686     py_includes = readCommand([python_config, '--includes'],
 687                               exception='').split()
 688     py_includes = list(filter(
 689         lambda s: match(r'.*\/include\/.*',s), py_includes))
 690     # Strip the -I from the include folders before adding them to the
 691     # CPPPATH
 692     py_includes = list(map(
 693         lambda s: s[2:] if s.startswith('-I') else s, py_includes))
 694     main.Append(CPPPATH=py_includes)
 695
 696     # Read the linker flags and split them into libraries and other link
 697     # flags. The libraries are added later through the call the CheckLib.
 698     # Note: starting in Python 3.8 the --embed flag is required to get the
 699     # -lpython3.8 linker flag
 700     retcode, cmd_stdout = readCommandWithReturn(
 701         [python_config, '--ldflags', '--embed'], exception='')
 702     if retcode != 0:
 703         # If --embed isn't detected then we're running python <3.8
 704         retcode, cmd_stdout = readCommandWithReturn(
 705             [python_config, '--ldflags'], exception='')
 706
 707     # Checking retcode again
 708     if retcode != 0:
 709         error("Failing on python-config --ldflags command")
 710
 711     py_ld_flags = cmd_stdout.split()
 712
 713     py_libs = []
 714     for lib in py_ld_flags:
 715          if not lib.startswith('-l'):
 716              main.Append(LINKFLAGS=[lib])
 717          else:
 718              lib = lib[2:]
 719              if lib not in py_libs:
 720                  py_libs.append(lib)
 721
 722     # verify that this stuff works
 723     if not conf.CheckHeader('Python.h', '<>'):
 724         error("Check failed for Python.h header in",
 725                 ' '.join(py_includes), "\n"
 726               "Two possible reasons:\n"
 727               "1. Python headers are not installed (You can install the "
 728               "package python-dev on Ubuntu and RedHat)\n"
 729               "2. SCons is using a wrong C compiler. This can happen if "
 730               "CC has the wrong value.\n"
 731               "CC = %s" % main['CC'])
 732
 733     for lib in py_libs:
 734         if not conf.CheckLib(lib):
 735             error("Can't find library %s required by python." % lib)
 736
 737 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
 738 # Bare minimum environment that only includes python
 739 marshal_env = main.Clone()
 740 marshal_env.Append(CCFLAGS='$MARSHAL_CCFLAGS_EXTRA')
 741 marshal_env.Append(LINKFLAGS='$MARSHAL_LDFLAGS_EXTRA')
 742
 743 # On Solaris you need to use libsocket for socket ops
 744 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 745    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 746                                   'C++', 'accept(0,0,0);'):
 747        error("Can't find library with socket calls (e.g. accept()).")
 748
 749 # Check for zlib.  If the check passes, libz will be automatically
 750 # added to the LIBS environment variable.
 751 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 752     error('Did not find needed zlib compression library '
 753           'and/or zlib.h header file.\n'
 754           'Please install zlib and try again.')
 755
 756 # If we have the protobuf compiler, also make sure we have the
 757 # development libraries. If the check passes, libprotobuf will be
 758 # automatically added to the LIBS environment variable. After
 759 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 760 # got both protoc and libprotobuf available.
 761 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 762     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 763                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 764
 765 # Valgrind gets much less confused if you tell it when you're using
 766 # alternative stacks.
 767 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 768
 769 # If we have the compiler but not the library, print another warning.
 770 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 771     warning('Did not find protocol buffer library and/or headers.\n'
 772             'Please install libprotobuf-dev for tracing support.')
 773
 774 # Check for librt.
 775 have_posix_clock = \
 776     conf.CheckLibWithHeader(None, 'time.h', 'C',
 777                             'clock_nanosleep(0,0,NULL,NULL);') or \
 778     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 779                             'clock_nanosleep(0,0,NULL,NULL);')
 780
 781 have_posix_timers = \
 782     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 783                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 784
 785 if not GetOption('without_tcmalloc'):
 786     if conf.CheckLib('tcmalloc'):
 787         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 788     elif conf.CheckLib('tcmalloc_minimal'):
 789         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 790     else:
 791         warning("You can get a 12% performance improvement by "
 792                 "installing tcmalloc (libgoogle-perftools-dev package "
 793                 "on Ubuntu or RedHat).")
 794
 795
 796 # Detect back trace implementations. The last implementation in the
 797 # list will be used by default.
 798 backtrace_impls = [ "none" ]
 799
 800 backtrace_checker = 'char temp;' + \
 801     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 802 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 803     backtrace_impls.append("glibc")
 804 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 805                              backtrace_checker):
 806     # NetBSD and FreeBSD need libexecinfo.
 807     backtrace_impls.append("glibc")
 808     main.Append(LIBS=['execinfo'])
 809
 810 if backtrace_impls[-1] == "none":
 811     default_backtrace_impl = "none"
 812     warning("No suitable back trace implementation found.")
 813
 814 if not have_posix_clock:
 815     warning("Can't find library for POSIX clocks.")
 816
 817 # Check for <fenv.h> (C99 FP environment control)
 818 have_fenv = conf.CheckHeader('fenv.h', '<>')
 819 if not have_fenv:
 820     warning("Header file <fenv.h> not found.\n"
 821             "This host has no IEEE FP rounding mode control.")
 822
 823 # Check for <png.h> (libpng library needed if wanting to dump
 824 # frame buffer image in png format)
 825 have_png = conf.CheckHeader('png.h', '<>')
 826 if not have_png:
 827     warning("Header file <png.h> not found.\n"
 828             "This host has no libpng library.\n"
 829             "Disabling support for PNG framebuffers.")
 830
 831 # Check if we should enable KVM-based hardware virtualization. The API
 832 # we rely on exists since version 2.6.36 of the kernel, but somehow
 833 # the KVM_API_VERSION does not reflect the change. We test for one of
 834 # the types as a fall back.
 835 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 836 if not have_kvm:
 837     print("Info: Compatible header file <linux/kvm.h> not found, "
 838           "disabling KVM support.")
 839
 840 # Check if the TUN/TAP driver is available.
 841 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 842 if not have_tuntap:
 843     print("Info: Compatible header file <linux/if_tun.h> not found.")
 844
 845 # x86 needs support for xsave. We test for the structure here since we
 846 # won't be able to run new tests by the time we know which ISA we're
 847 # targeting.
 848 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 849                                     '#include <linux/kvm.h>') != 0
 850
 851 # Check if the requested target ISA is compatible with the host
 852 def is_isa_kvm_compatible(isa):
 853     try:
 854         import platform
 855         host_isa = platform.machine()
 856     except:
 857         warning("Failed to determine host ISA.")
 858         return False
 859
 860     if not have_posix_timers:
 861         warning("Can not enable KVM, host seems to lack support "
 862                 "for POSIX timers")
 863         return False
 864
 865     if isa == "arm":
 866         return host_isa in ( "armv7l", "aarch64" )
 867     elif isa == "x86":
 868         if host_isa != "x86_64":
 869             return False
 870
 871         if not have_kvm_xsave:
 872             warning("KVM on x86 requires xsave support in kernel headers.")
 873             return False
 874
 875         return True
 876     else:
 877         return False
 878
 879
 880 # Check if the exclude_host attribute is available. We want this to
 881 # get accurate instruction counts in KVM.
 882 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 883     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 884
 885 def check_hdf5():
 886     return \
 887         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 888                                 'H5Fcreate("", 0, 0, 0);') and \
 889         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 890                                 'H5::H5File("", 0);')
 891
 892 def check_hdf5_pkg(name):
 893     print("Checking for %s using pkg-config..." % name, end="")
 894     if not have_pkg_config:
 895         print(" pkg-config not found")
 896         return False
 897
 898     try:
 899         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 900         print(" yes")
 901         return True
 902     except:
 903         print(" no")
 904         return False
 905
 906 # Check if there is a pkg-config configuration for hdf5. If we find
 907 # it, setup the environment to enable linking and header inclusion. We
 908 # don't actually try to include any headers or link with hdf5 at this
 909 # stage.
 910 if not check_hdf5_pkg('hdf5-serial'):
 911     check_hdf5_pkg('hdf5')
 912
 913 # Check if the HDF5 libraries can be found. This check respects the
 914 # include path and library path provided by pkg-config. We perform
 915 # this check even if there isn't a pkg-config configuration for hdf5
 916 # since some installations don't use pkg-config.
 917 have_hdf5 = check_hdf5()
 918 if not have_hdf5:
 919     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 920     print("         HDF5 support.")
 921
 922 ######################################################################
 923 #
 924 # Finish the configuration
 925 #
 926 main = conf.Finish()
 927
 928 ######################################################################
 929 #
 930 # Collect all non-global variables
 931 #
 932
 933 # Define the universe of supported ISAs
 934 all_isa_list = [ ]
 935 all_gpu_isa_list = [ ]
 936 Export('all_isa_list')
 937 Export('all_gpu_isa_list')
 938
 939 class CpuModel(object):
 940     '''The CpuModel class encapsulates everything the ISA parser needs to
 941     know about a particular CPU model.'''
 942
 943     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 944     dict = {}
 945
 946     # Constructor.  Automatically adds models to CpuModel.dict.
 947     def __init__(self, name, default=False):
 948         self.name = name           # name of model
 949
 950         # This cpu is enabled by default
 951         self.default = default
 952
 953         # Add self to dict
 954         if name in CpuModel.dict:
 955             raise AttributeError("CpuModel '%s' already registered" % name)
 956         CpuModel.dict[name] = self
 957
 958 Export('CpuModel')
 959
 960 # Sticky variables get saved in the variables file so they persist from
 961 # one invocation to the next (unless overridden, in which case the new
 962 # value becomes sticky).
 963 sticky_vars = Variables(args=ARGUMENTS)
 964 Export('sticky_vars')
 965
 966 # Sticky variables that should be exported
 967 export_vars = []
 968 Export('export_vars')
 969
 970 # For Ruby
 971 all_protocols = []
 972 Export('all_protocols')
 973 protocol_dirs = []
 974 Export('protocol_dirs')
 975 slicc_includes = []
 976 Export('slicc_includes')
 977
 978 # Walk the tree and execute all SConsopts scripts that wil add to the
 979 # above variables
 980 if GetOption('verbose'):
 981     print("Reading SConsopts")
 982 for bdir in [ base_dir ] + extras_dir_list:
 983     if not isdir(bdir):
 984         error("Directory '%s' does not exist." % bdir)
 985     for root, dirs, files in os.walk(bdir):
 986         if 'SConsopts' in files:
 987             if GetOption('verbose'):
 988                 print("Reading", joinpath(root, 'SConsopts'))
 989             SConscript(joinpath(root, 'SConsopts'))
 990
 991 all_isa_list.sort()
 992 all_gpu_isa_list.sort()
 993
 994 sticky_vars.AddVariables(
 995     EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list),
 996     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'gcn3', all_gpu_isa_list),
 997     ListVariable('CPU_MODELS', 'CPU models',
 998                  sorted(n for n,m in CpuModel.dict.items() if m.default),
 999                  sorted(CpuModel.dict.keys())),
1000     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1001                  False),
1002     BoolVariable('USE_SSE2',
1003                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1004                  False),
1005     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1006     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1007     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
1008     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
1009                  False),
1010     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1011                  have_kvm),
1012     BoolVariable('USE_TUNTAP',
1013                  'Enable using a tap device to bridge to the host network',
1014                  have_tuntap),
1015     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1016     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1017                   all_protocols),
1018     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1019                  backtrace_impls[-1], backtrace_impls),
1020     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1021                  64),
1022     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
1023     )
1024
1025 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1026 export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
1027                 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
1028                 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1029                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1030                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1031
1032 ###################################################
1033 #
1034 # Define a SCons builder for configuration flag headers.
1035 #
1036 ###################################################
1037
1038 # This function generates a config header file that #defines the
1039 # variable symbol to the current variable setting (0 or 1).  The source
1040 # operands are the name of the variable and a Value node containing the
1041 # value of the variable.
1042 def build_config_file(target, source, env):
1043     (variable, value) = [s.get_contents().decode('utf-8') for s in source]
1044     with open(str(target[0]), 'w') as f:
1045         print('#define', variable, value, file=f)
1046     return None
1047
1048 # Combine the two functions into a scons Action object.
1049 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1050
1051 # The emitter munges the source & target node lists to reflect what
1052 # we're really doing.
1053 def config_emitter(target, source, env):
1054     # extract variable name from Builder arg
1055     variable = str(target[0])
1056     # True target is config header file
1057     target = joinpath('config', variable.lower() + '.hh')
1058     val = env[variable]
1059     if isinstance(val, bool):
1060         # Force value to 0/1
1061         val = int(val)
1062     elif isinstance(val, str):
1063         val = '"' + val + '"'
1064
1065     # Sources are variable name & value (packaged in SCons Value nodes)
1066     return ([target], [Value(variable), Value(val)])
1067
1068 config_builder = Builder(emitter = config_emitter, action = config_action)
1069
1070 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1071
1072 ###################################################
1073 #
1074 # Builders for static and shared partially linked object files.
1075 #
1076 ###################################################
1077
1078 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1079                                  src_suffix='$OBJSUFFIX',
1080                                  src_builder=['StaticObject', 'Object'],
1081                                  LINKFLAGS='$PLINKFLAGS',
1082                                  LIBS='')
1083
1084 def partial_shared_emitter(target, source, env):
1085     for tgt in target:
1086         tgt.attributes.shared = 1
1087     return (target, source)
1088 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1089                                  emitter=partial_shared_emitter,
1090                                  src_suffix='$SHOBJSUFFIX',
1091                                  src_builder='SharedObject',
1092                                  SHLINKFLAGS='$PSHLINKFLAGS',
1093                                  LIBS='')
1094
1095 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1096                          'PartialStatic' : partial_static_builder })
1097
1098 def add_local_rpath(env, *targets):
1099     '''Set up an RPATH for a library which lives in the build directory.
1100
1101     The construction environment variable BIN_RPATH_PREFIX should be set to
1102     the relative path of the build directory starting from the location of the
1103     binary.'''
1104     for target in targets:
1105         target = env.Entry(target)
1106         if not isinstance(target, SCons.Node.FS.Dir):
1107             target = target.dir
1108         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1109         components = [
1110             '\\$$ORIGIN',
1111             '${BIN_RPATH_PREFIX}',
1112             relpath
1113         ]
1114         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1115
1116 if sys.platform != "darwin":
1117     main.Append(LINKFLAGS=Split('-z origin'))
1118
1119 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1120
1121 # builds in ext are shared across all configs in the build root.
1122 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1123 ext_build_dirs = []
1124 for root, dirs, files in os.walk(ext_dir):
1125     if 'SConscript' in files:
1126         build_dir = os.path.relpath(root, ext_dir)
1127         ext_build_dirs.append(build_dir)
1128         main.SConscript(joinpath(root, 'SConscript'),
1129                         variant_dir=joinpath(build_root, build_dir))
1130
1131 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1132 Export('gdb_xml_dir')
1133
1134 ###################################################
1135 #
1136 # This builder and wrapper method are used to set up a directory with
1137 # switching headers. Those are headers which are in a generic location and
1138 # that include more specific headers from a directory chosen at build time
1139 # based on the current build settings.
1140 #
1141 ###################################################
1142
1143 def build_switching_header(target, source, env):
1144     path = str(target[0])
1145     subdir = str(source[0])
1146     dp, fp = os.path.split(path)
1147     dp = os.path.relpath(os.path.realpath(dp),
1148                          os.path.realpath(env['BUILDDIR']))
1149     with open(path, 'w') as hdr:
1150         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1151
1152 switching_header_action = MakeAction(build_switching_header,
1153                                      Transform('GENERATE'))
1154
1155 switching_header_builder = Builder(action=switching_header_action,
1156                                    source_factory=Value,
1157                                    single_source=True)
1158
1159 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1160
1161 def switching_headers(self, headers, source):
1162     for header in headers:
1163         self.SwitchingHeader(header, source)
1164
1165 main.AddMethod(switching_headers, 'SwitchingHeaders')
1166
1167 ###################################################
1168 #
1169 # Define build environments for selected configurations.
1170 #
1171 ###################################################
1172
1173 for variant_path in variant_paths:
1174     if not GetOption('silent'):
1175         print("Building in", variant_path)
1176
1177     # Make a copy of the build-root environment to use for this config.
1178     env = main.Clone()
1179     env['BUILDDIR'] = variant_path
1180
1181     # variant_dir is the tail component of build path, and is used to
1182     # determine the build parameters (e.g., 'X86')
1183     (build_root, variant_dir) = splitpath(variant_path)
1184
1185     # Set env variables according to the build directory config.
1186     sticky_vars.files = []
1187     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1188     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1189     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1190     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1191     if isfile(current_vars_file):
1192         sticky_vars.files.append(current_vars_file)
1193         if not GetOption('silent'):
1194             print("Using saved variables file %s" % current_vars_file)
1195     elif variant_dir in ext_build_dirs:
1196         # Things in ext are built without a variant directory.
1197         continue
1198     else:
1199         # Build dir-specific variables file doesn't exist.
1200
1201         # Make sure the directory is there so we can create it later
1202         opt_dir = dirname(current_vars_file)
1203         if not isdir(opt_dir):
1204             mkdir(opt_dir)
1205
1206         # Get default build variables from source tree.  Variables are
1207         # normally determined by name of $VARIANT_DIR, but can be
1208         # overridden by '--default=' arg on command line.
1209         default = GetOption('default')
1210         opts_dir = joinpath(main.root.abspath, 'build_opts')
1211         if default:
1212             default_vars_files = [joinpath(build_root, 'variables', default),
1213                                   joinpath(opts_dir, default)]
1214         else:
1215             default_vars_files = [joinpath(opts_dir, variant_dir)]
1216         existing_files = list(filter(isfile, default_vars_files))
1217         if existing_files:
1218             default_vars_file = existing_files[0]
1219             sticky_vars.files.append(default_vars_file)
1220             print("Variables file %s not found,\n  using defaults in %s"
1221                   % (current_vars_file, default_vars_file))
1222         else:
1223             error("Cannot find variables file %s or default file(s) %s"
1224                   % (current_vars_file, ' or '.join(default_vars_files)))
1225             Exit(1)
1226
1227     # Apply current variable settings to env
1228     sticky_vars.Update(env)
1229
1230     help_texts["local_vars"] += \
1231         "Build variables for %s:\n" % variant_dir \
1232                  + sticky_vars.GenerateHelpText(env)
1233
1234     # Process variable settings.
1235
1236     if not have_fenv and env['USE_FENV']:
1237         warning("<fenv.h> not available; forcing USE_FENV to False in",
1238                 variant_dir + ".")
1239         env['USE_FENV'] = False
1240
1241     if not env['USE_FENV']:
1242         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1243                 "FP results may deviate slightly from other platforms.")
1244
1245     if not have_png and env['USE_PNG']:
1246         warning("<png.h> not available; forcing USE_PNG to False in",
1247                 variant_dir + ".")
1248         env['USE_PNG'] = False
1249
1250     if env['USE_PNG']:
1251         env.Append(LIBS=['png'])
1252
1253     if env['EFENCE']:
1254         env.Append(LIBS=['efence'])
1255
1256     if env['USE_KVM']:
1257         if not have_kvm:
1258             warning("Can not enable KVM, host seems to lack KVM support")
1259             env['USE_KVM'] = False
1260         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1261             print("Info: KVM support disabled due to unsupported host and "
1262                   "target ISA combination")
1263             env['USE_KVM'] = False
1264
1265     if env['USE_TUNTAP']:
1266         if not have_tuntap:
1267             warning("Can't connect EtherTap with a tap device.")
1268             env['USE_TUNTAP'] = False
1269
1270     if env['BUILD_GPU']:
1271         env.Append(CPPDEFINES=['BUILD_GPU'])
1272
1273     # Warn about missing optional functionality
1274     if env['USE_KVM']:
1275         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1276             warning("perf_event headers lack support for the exclude_host "
1277                     "attribute. KVM instruction counts will be inaccurate.")
1278
1279     # Save sticky variable settings back to current variables file
1280     sticky_vars.Save(current_vars_file, env)
1281
1282     if env['USE_SSE2']:
1283         env.Append(CCFLAGS=['-msse2'])
1284
1285     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1286     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1287
1288     # The src/SConscript file sets up the build rules in 'env' according
1289     # to the configured variables.  It returns a list of environments,
1290     # one for each variant build (debug, opt, etc.)
1291     SConscript('src/SConscript', variant_dir=variant_path,
1292                exports=['env', 'marshal_env'])
1293
1294 # base help text
1295 Help('''
1296 Usage: scons [scons options] [build variables] [target(s)]
1297
1298 Extra scons options:
1299 %(options)s
1300
1301 Global build variables:
1302 %(global_vars)s
1303
1304 %(local_vars)s
1305 ''' % help_texts)
1306
1307 atexit.register(summarize_warnings)