SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2013, 2015-2019 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 # Authors: Steve Reinhardt
  44 #          Nathan Binkert
  45
  46 ###################################################
  47 #
  48 # SCons top-level build description (SConstruct) file.
  49 #
  50 # While in this directory ('gem5'), just type 'scons' to build the default
  51 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
  52 # to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
  53 # the optimized full-system version).
  54 #
  55 # You can build gem5 in a different directory as long as there is a
  56 # 'build/<CONFIG>' somewhere along the target path.  The build system
  57 # expects that all configs under the same build directory are being
  58 # built for the same host system.
  59 #
  60 # Examples:
  61 #
  62 #   The following two commands are equivalent.  The '-u' option tells
  63 #   scons to search up the directory tree for this SConstruct file.
  64 #   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
  65 #   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
  66 #
  67 #   The following two commands are equivalent and demonstrate building
  68 #   in a directory outside of the source tree.  The '-C' option tells
  69 #   scons to chdir to the specified directory to find this SConstruct
  70 #   file.
  71 #   % cd <path-to-src>/gem5 ; scons /local/foo/build/ALPHA/gem5.debug
  72 #   % cd /local/foo/build/ALPHA; scons -C <path-to-src>/gem5 gem5.debug
  73 #
  74 # You can use 'scons -H' to print scons options.  If you're in this
  75 # 'gem5' directory (or use -u or -C to tell scons where to find this
  76 # file), you can use 'scons -h' to print all the gem5-specific build
  77 # options as well.
  78 #
  79 ###################################################
  80
  81 from __future__ import print_function
  82
  83 # Global Python includes
  84 import itertools
  85 import os
  86 import re
  87 import shutil
  88 import subprocess
  89 import sys
  90
  91 from os import mkdir, environ
  92 from os.path import abspath, basename, dirname, expanduser, normpath
  93 from os.path import exists,  isdir, isfile
  94 from os.path import join as joinpath, split as splitpath
  95 from re import match
  96
  97 # SCons includes
  98 import SCons
  99 import SCons.Node
 100 import SCons.Node.FS
 101
 102 from m5.util import compareVersions, readCommand
 103
 104 help_texts = {
 105     "options" : "",
 106     "global_vars" : "",
 107     "local_vars" : ""
 108 }
 109
 110 Export("help_texts")
 111
 112
 113 # There's a bug in scons in that (1) by default, the help texts from
 114 # AddOption() are supposed to be displayed when you type 'scons -h'
 115 # and (2) you can override the help displayed by 'scons -h' using the
 116 # Help() function, but these two features are incompatible: once
 117 # you've overridden the help text using Help(), there's no way to get
 118 # at the help texts from AddOptions.  See:
 119 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 120 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 121 # This hack lets us extract the help text from AddOptions and
 122 # re-inject it via Help().  Ideally someday this bug will be fixed and
 123 # we can just use AddOption directly.
 124 def AddLocalOption(*args, **kwargs):
 125     col_width = 30
 126
 127     help = "  " + ", ".join(args)
 128     if "help" in kwargs:
 129         length = len(help)
 130         if length >= col_width:
 131             help += "\n" + " " * col_width
 132         else:
 133             help += " " * (col_width - length)
 134         help += kwargs["help"]
 135     help_texts["options"] += help + "\n"
 136
 137     AddOption(*args, **kwargs)
 138
 139 AddLocalOption('--colors', dest='use_colors', action='store_true',
 140                help="Add color to abbreviated scons output")
 141 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 142                help="Don't add color to abbreviated scons output")
 143 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 144                action='store_true',
 145                help="Build with support for C++-based configuration")
 146 AddLocalOption('--default', dest='default', type='string', action='store',
 147                help='Override which build_opts file to use for defaults')
 148 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 149                help='Disable style checking hooks')
 150 AddLocalOption('--gold-linker', dest='gold_linker', action='store_true',
 151                help='Use the gold linker')
 152 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 153                help='Disable Link-Time Optimization for fast')
 154 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 155                help='Use Link-Time Optimization instead of partial linking' +
 156                     ' when the compiler doesn\'t support using them together.')
 157 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 158                help='Update test reference outputs')
 159 AddLocalOption('--verbose', dest='verbose', action='store_true',
 160                help='Print full tool command lines')
 161 AddLocalOption('--without-python', dest='without_python',
 162                action='store_true',
 163                help='Build without Python configuration support')
 164 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 165                action='store_true',
 166                help='Disable linking against tcmalloc')
 167 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 168                help='Build with Undefined Behavior Sanitizer if available')
 169 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 170                help='Build with Address Sanitizer if available')
 171
 172 from gem5_scons import Transform, error, warning
 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/ALPHA/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 def find_first_prog(prog_names):
 219     """Find the absolute path to the first existing binary in prog_names"""
 220
 221     if not isinstance(prog_names, (list, tuple)):
 222         prog_names = [ prog_names ]
 223
 224     for p in prog_names:
 225         p = main.WhereIs(p)
 226         if p is not None:
 227             return p
 228
 229     return None
 230
 231 # Each target must have 'build' in the interior of the path; the
 232 # directory below this will determine the build parameters.  For
 233 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 234 # recognize that ALPHA_SE specifies the configuration because it
 235 # follow 'build' in the build path.
 236
 237 # The funky assignment to "[:]" is needed to replace the list contents
 238 # in place rather than reassign the symbol to a new list, which
 239 # doesn't work (obviously!).
 240 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 241
 242 # Generate a list of the unique build roots and configs that the
 243 # collected targets reference.
 244 variant_paths = []
 245 build_root = None
 246 for t in BUILD_TARGETS:
 247     path_dirs = t.split('/')
 248     try:
 249         build_top = rfind(path_dirs, 'build', -2)
 250     except:
 251         error("No non-leaf 'build' dir found on target path.", t)
 252     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 253     if not build_root:
 254         build_root = this_build_root
 255     else:
 256         if this_build_root != build_root:
 257             error("build targets not under same build root\n"
 258                   "  %s\n  %s" % (build_root, this_build_root))
 259     variant_path = joinpath('/',*path_dirs[:build_top+2])
 260     if variant_path not in variant_paths:
 261         variant_paths.append(variant_path)
 262
 263 # Make sure build_root exists (might not if this is the first build there)
 264 if not isdir(build_root):
 265     mkdir(build_root)
 266 main['BUILDROOT'] = build_root
 267
 268 Export('main')
 269
 270 main.SConsignFile(joinpath(build_root, "sconsign"))
 271
 272 # Default duplicate option is to use hard links, but this messes up
 273 # when you use emacs to edit a file in the target dir, as emacs moves
 274 # file to file~ then copies to file, breaking the link.  Symbolic
 275 # (soft) links work better.
 276 main.SetOption('duplicate', 'soft-copy')
 277
 278 #
 279 # Set up global sticky variables... these are common to an entire build
 280 # tree (not specific to a particular build like ALPHA_SE)
 281 #
 282
 283 global_vars_file = joinpath(build_root, 'variables.global')
 284
 285 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 286
 287 global_vars.AddVariables(
 288     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 289     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 290     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 291     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 292     ('PYTHON_CONFIG', 'Python config binary to use',
 293      [ 'python2.7-config', 'python-config' ]),
 294     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 295     ('BATCH', 'Use batch pool for build and tests', False),
 296     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 297     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 298     ('EXTRAS', 'Add extra directories to the compilation', '')
 299     )
 300
 301 # Update main environment with values from ARGUMENTS & global_vars_file
 302 global_vars.Update(main)
 303 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 304
 305 # Save sticky variable settings back to current variables file
 306 global_vars.Save(global_vars_file, main)
 307
 308 # Parse EXTRAS variable to build list of all directories where we're
 309 # look for sources etc.  This list is exported as extras_dir_list.
 310 base_dir = main.srcdir.abspath
 311 if main['EXTRAS']:
 312     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 313 else:
 314     extras_dir_list = []
 315
 316 Export('base_dir')
 317 Export('extras_dir_list')
 318
 319 # the ext directory should be on the #includes path
 320 main.Append(CPPPATH=[Dir('ext')])
 321
 322 # Add shared top-level headers
 323 main.Prepend(CPPPATH=Dir('include'))
 324
 325 if GetOption('verbose'):
 326     def MakeAction(action, string, *args, **kwargs):
 327         return Action(action, *args, **kwargs)
 328 else:
 329     MakeAction = Action
 330     main['CCCOMSTR']        = Transform("CC")
 331     main['CXXCOMSTR']       = Transform("CXX")
 332     main['ASCOMSTR']        = Transform("AS")
 333     main['ARCOMSTR']        = Transform("AR", 0)
 334     main['LINKCOMSTR']      = Transform("LINK", 0)
 335     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 336     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 337     main['M4COMSTR']        = Transform("M4")
 338     main['SHCCCOMSTR']      = Transform("SHCC")
 339     main['SHCXXCOMSTR']     = Transform("SHCXX")
 340 Export('MakeAction')
 341
 342 # Initialize the Link-Time Optimization (LTO) flags
 343 main['LTO_CCFLAGS'] = []
 344 main['LTO_LDFLAGS'] = []
 345
 346 # According to the readme, tcmalloc works best if the compiler doesn't
 347 # assume that we're using the builtin malloc and friends. These flags
 348 # are compiler-specific, so we need to set them after we detect which
 349 # compiler we're using.
 350 main['TCMALLOC_CCFLAGS'] = []
 351
 352 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 353 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 354
 355 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 356 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 357 if main['GCC'] + main['CLANG'] > 1:
 358     error('Two compilers enabled at once?')
 359
 360 # Set up default C++ compiler flags
 361 if main['GCC'] or main['CLANG']:
 362     # As gcc and clang share many flags, do the common parts here
 363     main.Append(CCFLAGS=['-pipe'])
 364     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 365     # Enable -Wall and -Wextra and then disable the few warnings that
 366     # we consistently violate
 367     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 368                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 369     # We always compile using C++11
 370     main.Append(CXXFLAGS=['-std=c++11'])
 371     if sys.platform.startswith('freebsd'):
 372         main.Append(CCFLAGS=['-I/usr/local/include'])
 373         main.Append(CXXFLAGS=['-I/usr/local/include'])
 374
 375     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 376     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 377     if GetOption('gold_linker'):
 378         main.Append(LINKFLAGS='-fuse-ld=gold')
 379     main['PLINKFLAGS'] = main.subst('${LINKFLAGS}')
 380     shared_partial_flags = ['-r', '-nostdlib']
 381     main.Append(PSHLINKFLAGS=shared_partial_flags)
 382     main.Append(PLINKFLAGS=shared_partial_flags)
 383
 384     # Treat warnings as errors but white list some warnings that we
 385     # want to allow (e.g., deprecation warnings).
 386     main.Append(CCFLAGS=['-Werror',
 387                          '-Wno-error=deprecated-declarations',
 388                          '-Wno-error=deprecated',
 389                         ])
 390 else:
 391     error('\n'.join(
 392           "Don't know what compiler options to use for your compiler.",
 393           "compiler: " + main['CXX'],
 394           "version: " + CXX_version.replace('\n', '<nl>') if
 395                 CXX_version else 'COMMAND NOT FOUND!',
 396           "If you're trying to use a compiler other than GCC",
 397           "or clang, there appears to be something wrong with your",
 398           "environment.",
 399           "",
 400           "If you are trying to use a compiler other than those listed",
 401           "above you will need to ease fix SConstruct and ",
 402           "src/SConscript to support that compiler."))
 403
 404 if main['GCC']:
 405     # Check for a supported version of gcc. >= 4.8 is chosen for its
 406     # level of c++11 support. See
 407     # http://gcc.gnu.org/projects/cxx0x.html for details.
 408     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 409     if compareVersions(gcc_version, "4.8") < 0:
 410         error('gcc version 4.8 or newer required.\n'
 411               'Installed version:', gcc_version)
 412         Exit(1)
 413
 414     main['GCC_VERSION'] = gcc_version
 415
 416     if compareVersions(gcc_version, '4.9') >= 0:
 417         # Incremental linking with LTO is currently broken in gcc versions
 418         # 4.9 and above. A version where everything works completely hasn't
 419         # yet been identified.
 420         #
 421         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 422         main['BROKEN_INCREMENTAL_LTO'] = True
 423     if compareVersions(gcc_version, '6.0') >= 0:
 424         # gcc versions 6.0 and greater accept an -flinker-output flag which
 425         # selects what type of output the linker should generate. This is
 426         # necessary for incremental lto to work, but is also broken in
 427         # current versions of gcc. It may not be necessary in future
 428         # versions. We add it here since it might be, and as a reminder that
 429         # it exists. It's excluded if lto is being forced.
 430         #
 431         # https://gcc.gnu.org/gcc-6/changes.html
 432         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 433         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 434         if not GetOption('force_lto'):
 435             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 436             main.Append(PLINKFLAGS='-flinker-output=rel')
 437
 438     # Make sure we warn if the user has requested to compile with the
 439     # Undefined Benahvior Sanitizer and this version of gcc does not
 440     # support it.
 441     if GetOption('with_ubsan') and compareVersions(gcc_version, '4.9') < 0:
 442         warning('UBSan is only supported using gcc 4.9 and later.')
 443
 444     disable_lto = GetOption('no_lto')
 445     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 446             not GetOption('force_lto'):
 447         warning('Warning: Your compiler doesn\'t support incremental linking '
 448                 'and lto at the same time, so lto is being disabled. To force '
 449                 'lto on anyway, use the --force-lto option. That will disable '
 450                 'partial linking.')
 451         disable_lto = True
 452
 453     # Add the appropriate Link-Time Optimization (LTO) flags
 454     # unless LTO is explicitly turned off. Note that these flags
 455     # are only used by the fast target.
 456     if not disable_lto:
 457         # Pass the LTO flag when compiling to produce GIMPLE
 458         # output, we merely create the flags here and only append
 459         # them later
 460         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 461
 462         # Use the same amount of jobs for LTO as we are running
 463         # scons with
 464         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 465
 466     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 467                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 468
 469     # The address sanitizer is available for gcc >= 4.8
 470     if GetOption('with_asan'):
 471         if GetOption('with_ubsan') and \
 472                 compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 473             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 474                                  '-fno-omit-frame-pointer'],
 475                         LINKFLAGS='-fsanitize=address,undefined')
 476         else:
 477             main.Append(CCFLAGS=['-fsanitize=address',
 478                                  '-fno-omit-frame-pointer'],
 479                         LINKFLAGS='-fsanitize=address')
 480     # Only gcc >= 4.9 supports UBSan, so check both the version
 481     # and the command-line option before adding the compiler and
 482     # linker flags.
 483     elif GetOption('with_ubsan') and \
 484             compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 485         main.Append(CCFLAGS='-fsanitize=undefined')
 486         main.Append(LINKFLAGS='-fsanitize=undefined')
 487
 488 elif main['CLANG']:
 489     # Check for a supported version of clang, >= 3.1 is needed to
 490     # support similar features as gcc 4.8. See
 491     # http://clang.llvm.org/cxx_status.html for details
 492     clang_version_re = re.compile(".* version (\d+\.\d+)")
 493     clang_version_match = clang_version_re.search(CXX_version)
 494     if (clang_version_match):
 495         clang_version = clang_version_match.groups()[0]
 496         if compareVersions(clang_version, "3.1") < 0:
 497             error('clang version 3.1 or newer required.\n'
 498                   'Installed version:', clang_version)
 499     else:
 500         error('Unable to determine clang version.')
 501
 502     # clang has a few additional warnings that we disable, extraneous
 503     # parantheses are allowed due to Ruby's printing of the AST,
 504     # finally self assignments are allowed as the generated CPU code
 505     # is relying on this
 506     main.Append(CCFLAGS=['-Wno-parentheses',
 507                          '-Wno-self-assign',
 508                          # Some versions of libstdc++ (4.8?) seem to
 509                          # use struct hash and class hash
 510                          # interchangeably.
 511                          '-Wno-mismatched-tags',
 512                          ])
 513
 514     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 515
 516     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 517     # opposed to libstdc++, as the later is dated.
 518     if sys.platform == "darwin":
 519         main.Append(CXXFLAGS=['-stdlib=libc++'])
 520         main.Append(LIBS=['c++'])
 521
 522     # On FreeBSD we need libthr.
 523     if sys.platform.startswith('freebsd'):
 524         main.Append(LIBS=['thr'])
 525
 526     # We require clang >= 3.1, so there is no need to check any
 527     # versions here.
 528     if GetOption('with_ubsan'):
 529         if GetOption('with_asan'):
 530             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 531                                  '-fno-omit-frame-pointer'],
 532                        LINKFLAGS='-fsanitize=address,undefined')
 533         else:
 534             main.Append(CCFLAGS='-fsanitize=undefined',
 535                         LINKFLAGS='-fsanitize=undefined')
 536
 537     elif GetOption('with_asan'):
 538         main.Append(CCFLAGS=['-fsanitize=address',
 539                              '-fno-omit-frame-pointer'],
 540                    LINKFLAGS='-fsanitize=address')
 541
 542 # Set up common yacc/bison flags (needed for Ruby)
 543 main['YACCFLAGS'] = '-d'
 544 main['YACCHXXFILESUFFIX'] = '.hh'
 545
 546 # Do this after we save setting back, or else we'll tack on an
 547 # extra 'qdo' every time we run scons.
 548 if main['BATCH']:
 549     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 550     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 551     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 552     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 553     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 554
 555 if sys.platform == 'cygwin':
 556     # cygwin has some header file issues...
 557     main.Append(CCFLAGS=["-Wno-uninitialized"])
 558
 559
 560 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 561
 562 # Check for the protobuf compiler
 563 try:
 564     main['HAVE_PROTOC'] = True
 565     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 566
 567     # First two words should be "libprotoc x.y.z"
 568     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 569         warning('Protocol buffer compiler (protoc) not found.\n'
 570                 'Please install protobuf-compiler for tracing support.')
 571         main['HAVE_PROTOC'] = False
 572     else:
 573         # Based on the availability of the compress stream wrappers,
 574         # require 2.1.0
 575         min_protoc_version = '2.1.0'
 576         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 577             warning('protoc version', min_protoc_version,
 578                     'or newer required.\n'
 579                     'Installed version:', protoc_version[1])
 580             main['HAVE_PROTOC'] = False
 581         else:
 582             # Attempt to determine the appropriate include path and
 583             # library path using pkg-config, that means we also need to
 584             # check for pkg-config. Note that it is possible to use
 585             # protobuf without the involvement of pkg-config. Later on we
 586             # check go a library config check and at that point the test
 587             # will fail if libprotobuf cannot be found.
 588             if have_pkg_config:
 589                 try:
 590                     # Attempt to establish what linking flags to add for
 591                     # protobuf
 592                     # using pkg-config
 593                     main.ParseConfig(
 594                             'pkg-config --cflags --libs-only-L protobuf')
 595                 except:
 596                     warning('pkg-config could not get protobuf flags.')
 597 except Exception as e:
 598     warning('While checking protoc version:', str(e))
 599     main['HAVE_PROTOC'] = False
 600
 601 # Check for 'timeout' from GNU coreutils. If present, regressions will
 602 # be run with a time limit. We require version 8.13 since we rely on
 603 # support for the '--foreground' option.
 604 if sys.platform.startswith('freebsd'):
 605     timeout_lines = readCommand(['gtimeout', '--version'],
 606                                 exception='').splitlines()
 607 else:
 608     timeout_lines = readCommand(['timeout', '--version'],
 609                                 exception='').splitlines()
 610 # Get the first line and tokenize it
 611 timeout_version = timeout_lines[0].split() if timeout_lines else []
 612 main['TIMEOUT'] =  timeout_version and \
 613     compareVersions(timeout_version[-1], '8.13') >= 0
 614
 615 # Add a custom Check function to test for structure members.
 616 def CheckMember(context, include, decl, member, include_quotes="<>"):
 617     context.Message("Checking for member %s in %s..." %
 618                     (member, decl))
 619     text = """
 620 #include %(header)s
 621 int main(){
 622   %(decl)s test;
 623   (void)test.%(member)s;
 624   return 0;
 625 };
 626 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 627         "decl" : decl,
 628         "member" : member,
 629         }
 630
 631     ret = context.TryCompile(text, extension=".cc")
 632     context.Result(ret)
 633     return ret
 634
 635 # Platform-specific configuration.  Note again that we assume that all
 636 # builds under a given build root run on the same host platform.
 637 conf = Configure(main,
 638                  conf_dir = joinpath(build_root, '.scons_config'),
 639                  log_file = joinpath(build_root, 'scons_config.log'),
 640                  custom_tests = {
 641         'CheckMember' : CheckMember,
 642         })
 643
 644 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 645 try:
 646     import platform
 647     uname = platform.uname()
 648     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 649         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 650             main.Append(CCFLAGS=['-arch', 'x86_64'])
 651             main.Append(CFLAGS=['-arch', 'x86_64'])
 652             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 653             main.Append(ASFLAGS=['-arch', 'x86_64'])
 654 except:
 655     pass
 656
 657 # Recent versions of scons substitute a "Null" object for Configure()
 658 # when configuration isn't necessary, e.g., if the "--help" option is
 659 # present.  Unfortuantely this Null object always returns false,
 660 # breaking all our configuration checks.  We replace it with our own
 661 # more optimistic null object that returns True instead.
 662 if not conf:
 663     def NullCheck(*args, **kwargs):
 664         return True
 665
 666     class NullConf:
 667         def __init__(self, env):
 668             self.env = env
 669         def Finish(self):
 670             return self.env
 671         def __getattr__(self, mname):
 672             return NullCheck
 673
 674     conf = NullConf(main)
 675
 676 # Cache build files in the supplied directory.
 677 if main['M5_BUILD_CACHE']:
 678     print('Using build cache located at', main['M5_BUILD_CACHE'])
 679     CacheDir(main['M5_BUILD_CACHE'])
 680
 681 main['USE_PYTHON'] = not GetOption('without_python')
 682 if main['USE_PYTHON']:
 683     # Find Python include and library directories for embedding the
 684     # interpreter. We rely on python-config to resolve the appropriate
 685     # includes and linker flags. ParseConfig does not seem to understand
 686     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 687     # we add them explicitly below. If you want to link in an alternate
 688     # version of python, see above for instructions on how to invoke
 689     # scons with the appropriate PATH set.
 690
 691     python_config = find_first_prog(main['PYTHON_CONFIG'])
 692     if python_config is None:
 693         error("Can't find a suitable python-config, tried %s" % \
 694               main['PYTHON_CONFIG'])
 695
 696     print("Info: Using Python config: %s" % (python_config, ))
 697     py_includes = readCommand([python_config, '--includes'],
 698                               exception='').split()
 699     py_includes = filter(lambda s: match(r'.*\/include\/.*',s), py_includes)
 700     # Strip the -I from the include folders before adding them to the
 701     # CPPPATH
 702     py_includes = map(lambda s: s[2:] if s.startswith('-I') else s, py_includes)
 703     main.Append(CPPPATH=py_includes)
 704
 705     # Read the linker flags and split them into libraries and other link
 706     # flags. The libraries are added later through the call the CheckLib.
 707     py_ld_flags = readCommand([python_config, '--ldflags'],
 708         exception='').split()
 709     py_libs = []
 710     for lib in py_ld_flags:
 711          if not lib.startswith('-l'):
 712              main.Append(LINKFLAGS=[lib])
 713          else:
 714              lib = lib[2:]
 715              if lib not in py_libs:
 716                  py_libs.append(lib)
 717
 718     # verify that this stuff works
 719     if not conf.CheckHeader('Python.h', '<>'):
 720         error("Check failed for Python.h header in", py_includes, "\n"
 721               "Two possible reasons:\n"
 722               "1. Python headers are not installed (You can install the "
 723               "package python-dev on Ubuntu and RedHat)\n"
 724               "2. SCons is using a wrong C compiler. This can happen if "
 725               "CC has the wrong value.\n"
 726               "CC = %s" % main['CC'])
 727
 728     for lib in py_libs:
 729         if not conf.CheckLib(lib):
 730             error("Can't find library %s required by python." % lib)
 731
 732 # On Solaris you need to use libsocket for socket ops
 733 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 734    if not conf.CheckLibWithHeader('socket', 'sys/socket.h',
 735                                   'C++', 'accept(0,0,0);'):
 736        error("Can't find library with socket calls (e.g. accept()).")
 737
 738 # Check for zlib.  If the check passes, libz will be automatically
 739 # added to the LIBS environment variable.
 740 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 741     error('Did not find needed zlib compression library '
 742           'and/or zlib.h header file.\n'
 743           'Please install zlib and try again.')
 744
 745 # If we have the protobuf compiler, also make sure we have the
 746 # development libraries. If the check passes, libprotobuf will be
 747 # automatically added to the LIBS environment variable. After
 748 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 749 # got both protoc and libprotobuf available.
 750 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 751     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 752                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 753
 754 # Valgrind gets much less confused if you tell it when you're using
 755 # alternative stacks.
 756 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 757
 758 # If we have the compiler but not the library, print another warning.
 759 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 760     warning('Did not find protocol buffer library and/or headers.\n'
 761             'Please install libprotobuf-dev for tracing support.')
 762
 763 # Check for librt.
 764 have_posix_clock = \
 765     conf.CheckLibWithHeader(None, 'time.h', 'C',
 766                             'clock_nanosleep(0,0,NULL,NULL);') or \
 767     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 768                             'clock_nanosleep(0,0,NULL,NULL);')
 769
 770 have_posix_timers = \
 771     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 772                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 773
 774 if not GetOption('without_tcmalloc'):
 775     if conf.CheckLib('tcmalloc'):
 776         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 777     elif conf.CheckLib('tcmalloc_minimal'):
 778         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 779     else:
 780         warning("You can get a 12% performance improvement by "
 781                 "installing tcmalloc (libgoogle-perftools-dev package "
 782                 "on Ubuntu or RedHat).")
 783
 784
 785 # Detect back trace implementations. The last implementation in the
 786 # list will be used by default.
 787 backtrace_impls = [ "none" ]
 788
 789 backtrace_checker = 'char temp;' + \
 790     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 791 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 792     backtrace_impls.append("glibc")
 793 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 794                              backtrace_checker):
 795     # NetBSD and FreeBSD need libexecinfo.
 796     backtrace_impls.append("glibc")
 797     main.Append(LIBS=['execinfo'])
 798
 799 if backtrace_impls[-1] == "none":
 800     default_backtrace_impl = "none"
 801     warning("No suitable back trace implementation found.")
 802
 803 if not have_posix_clock:
 804     warning("Can't find library for POSIX clocks.")
 805
 806 # Check for <fenv.h> (C99 FP environment control)
 807 have_fenv = conf.CheckHeader('fenv.h', '<>')
 808 if not have_fenv:
 809     warning("Header file <fenv.h> not found.\n"
 810             "This host has no IEEE FP rounding mode control.")
 811
 812 # Check for <png.h> (libpng library needed if wanting to dump
 813 # frame buffer image in png format)
 814 have_png = conf.CheckHeader('png.h', '<>')
 815 if not have_png:
 816     warning("Header file <png.h> not found.\n"
 817             "This host has no libpng library.\n"
 818             "Disabling support for PNG framebuffers.")
 819
 820 # Check if we should enable KVM-based hardware virtualization. The API
 821 # we rely on exists since version 2.6.36 of the kernel, but somehow
 822 # the KVM_API_VERSION does not reflect the change. We test for one of
 823 # the types as a fall back.
 824 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 825 if not have_kvm:
 826     print("Info: Compatible header file <linux/kvm.h> not found, "
 827           "disabling KVM support.")
 828
 829 # Check if the TUN/TAP driver is available.
 830 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 831 if not have_tuntap:
 832     print("Info: Compatible header file <linux/if_tun.h> not found.")
 833
 834 # x86 needs support for xsave. We test for the structure here since we
 835 # won't be able to run new tests by the time we know which ISA we're
 836 # targeting.
 837 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 838                                     '#include <linux/kvm.h>') != 0
 839
 840 # Check if the requested target ISA is compatible with the host
 841 def is_isa_kvm_compatible(isa):
 842     try:
 843         import platform
 844         host_isa = platform.machine()
 845     except:
 846         warning("Failed to determine host ISA.")
 847         return False
 848
 849     if not have_posix_timers:
 850         warning("Can not enable KVM, host seems to lack support "
 851                 "for POSIX timers")
 852         return False
 853
 854     if isa == "arm":
 855         return host_isa in ( "armv7l", "aarch64" )
 856     elif isa == "x86":
 857         if host_isa != "x86_64":
 858             return False
 859
 860         if not have_kvm_xsave:
 861             warning("KVM on x86 requires xsave support in kernel headers.")
 862             return False
 863
 864         return True
 865     else:
 866         return False
 867
 868
 869 # Check if the exclude_host attribute is available. We want this to
 870 # get accurate instruction counts in KVM.
 871 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 872     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 873
 874 def check_hdf5():
 875     return \
 876         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 877                                 'H5Fcreate("", 0, 0, 0);') and \
 878         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 879                                 'H5::H5File("", 0);')
 880
 881 def check_hdf5_pkg(name):
 882     print("Checking for %s using pkg-config..." % name, end="")
 883     if not have_pkg_config:
 884         print(" pkg-config not found")
 885         return False
 886
 887     try:
 888         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 889         print(" yes")
 890         return True
 891     except:
 892         print(" no")
 893         return False
 894
 895 # Check if there is a pkg-config configuration for hdf5. If we find
 896 # it, setup the environment to enable linking and header inclusion. We
 897 # don't actually try to include any headers or link with hdf5 at this
 898 # stage.
 899 if not check_hdf5_pkg('hdf5-serial'):
 900     check_hdf5_pkg('hdf5')
 901
 902 # Check if the HDF5 libraries can be found. This check respects the
 903 # include path and library path provided by pkg-config. We perform
 904 # this check even if there isn't a pkg-config configuration for hdf5
 905 # since some installations don't use pkg-config.
 906 have_hdf5 = check_hdf5()
 907 if not have_hdf5:
 908     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 909     print("         HDF5 support.")
 910
 911 ######################################################################
 912 #
 913 # Finish the configuration
 914 #
 915 main = conf.Finish()
 916
 917 ######################################################################
 918 #
 919 # Collect all non-global variables
 920 #
 921
 922 # Define the universe of supported ISAs
 923 all_isa_list = [ ]
 924 all_gpu_isa_list = [ ]
 925 Export('all_isa_list')
 926 Export('all_gpu_isa_list')
 927
 928 class CpuModel(object):
 929     '''The CpuModel class encapsulates everything the ISA parser needs to
 930     know about a particular CPU model.'''
 931
 932     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 933     dict = {}
 934
 935     # Constructor.  Automatically adds models to CpuModel.dict.
 936     def __init__(self, name, default=False):
 937         self.name = name           # name of model
 938
 939         # This cpu is enabled by default
 940         self.default = default
 941
 942         # Add self to dict
 943         if name in CpuModel.dict:
 944             raise AttributeError, "CpuModel '%s' already registered" % name
 945         CpuModel.dict[name] = self
 946
 947 Export('CpuModel')
 948
 949 # Sticky variables get saved in the variables file so they persist from
 950 # one invocation to the next (unless overridden, in which case the new
 951 # value becomes sticky).
 952 sticky_vars = Variables(args=ARGUMENTS)
 953 Export('sticky_vars')
 954
 955 # Sticky variables that should be exported
 956 export_vars = []
 957 Export('export_vars')
 958
 959 # For Ruby
 960 all_protocols = []
 961 Export('all_protocols')
 962 protocol_dirs = []
 963 Export('protocol_dirs')
 964 slicc_includes = []
 965 Export('slicc_includes')
 966
 967 # Walk the tree and execute all SConsopts scripts that wil add to the
 968 # above variables
 969 if GetOption('verbose'):
 970     print("Reading SConsopts")
 971 for bdir in [ base_dir ] + extras_dir_list:
 972     if not isdir(bdir):
 973         error("Directory '%s' does not exist." % bdir)
 974     for root, dirs, files in os.walk(bdir):
 975         if 'SConsopts' in files:
 976             if GetOption('verbose'):
 977                 print("Reading", joinpath(root, 'SConsopts'))
 978             SConscript(joinpath(root, 'SConsopts'))
 979
 980 all_isa_list.sort()
 981 all_gpu_isa_list.sort()
 982
 983 sticky_vars.AddVariables(
 984     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 985     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 986     ListVariable('CPU_MODELS', 'CPU models',
 987                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
 988                  sorted(CpuModel.dict.keys())),
 989     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 990                  False),
 991     BoolVariable('SS_COMPATIBLE_FP',
 992                  'Make floating-point results compatible with SimpleScalar',
 993                  False),
 994     BoolVariable('USE_SSE2',
 995                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 996                  False),
 997     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 998     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 999     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
1000     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
1001                  False),
1002     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1003                  have_kvm),
1004     BoolVariable('USE_TUNTAP',
1005                  'Enable using a tap device to bridge to the host network',
1006                  have_tuntap),
1007     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1008     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1009                   all_protocols),
1010     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1011                  backtrace_impls[-1], backtrace_impls),
1012     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1013                  64),
1014     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
1015     )
1016
1017 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1018 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1019                 'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP',
1020                 'PROTOCOL', 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1021                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1022                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1023
1024 ###################################################
1025 #
1026 # Define a SCons builder for configuration flag headers.
1027 #
1028 ###################################################
1029
1030 # This function generates a config header file that #defines the
1031 # variable symbol to the current variable setting (0 or 1).  The source
1032 # operands are the name of the variable and a Value node containing the
1033 # value of the variable.
1034 def build_config_file(target, source, env):
1035     (variable, value) = [s.get_contents() for s in source]
1036     f = file(str(target[0]), 'w')
1037     print('#define', variable, value, file=f)
1038     f.close()
1039     return None
1040
1041 # Combine the two functions into a scons Action object.
1042 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1043
1044 # The emitter munges the source & target node lists to reflect what
1045 # we're really doing.
1046 def config_emitter(target, source, env):
1047     # extract variable name from Builder arg
1048     variable = str(target[0])
1049     # True target is config header file
1050     target = joinpath('config', variable.lower() + '.hh')
1051     val = env[variable]
1052     if isinstance(val, bool):
1053         # Force value to 0/1
1054         val = int(val)
1055     elif isinstance(val, str):
1056         val = '"' + val + '"'
1057
1058     # Sources are variable name & value (packaged in SCons Value nodes)
1059     return ([target], [Value(variable), Value(val)])
1060
1061 config_builder = Builder(emitter = config_emitter, action = config_action)
1062
1063 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1064
1065 ###################################################
1066 #
1067 # Builders for static and shared partially linked object files.
1068 #
1069 ###################################################
1070
1071 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1072                                  src_suffix='$OBJSUFFIX',
1073                                  src_builder=['StaticObject', 'Object'],
1074                                  LINKFLAGS='$PLINKFLAGS',
1075                                  LIBS='')
1076
1077 def partial_shared_emitter(target, source, env):
1078     for tgt in target:
1079         tgt.attributes.shared = 1
1080     return (target, source)
1081 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1082                                  emitter=partial_shared_emitter,
1083                                  src_suffix='$SHOBJSUFFIX',
1084                                  src_builder='SharedObject',
1085                                  SHLINKFLAGS='$PSHLINKFLAGS',
1086                                  LIBS='')
1087
1088 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1089                          'PartialStatic' : partial_static_builder })
1090
1091 def add_local_rpath(env, *targets):
1092     '''Set up an RPATH for a library which lives in the build directory.
1093
1094     The construction environment variable BIN_RPATH_PREFIX should be set to
1095     the relative path of the build directory starting from the location of the
1096     binary.'''
1097     for target in targets:
1098         target = env.Entry(target)
1099         if not isinstance(target, SCons.Node.FS.Dir):
1100             target = target.dir
1101         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1102         components = [
1103             '\\$$ORIGIN',
1104             '${BIN_RPATH_PREFIX}',
1105             relpath
1106         ]
1107         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1108
1109 if sys.platform != "darwin":
1110     main.Append(LINKFLAGS=Split('-z origin'))
1111
1112 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1113
1114 # builds in ext are shared across all configs in the build root.
1115 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1116 ext_build_dirs = []
1117 for root, dirs, files in os.walk(ext_dir):
1118     if 'SConscript' in files:
1119         build_dir = os.path.relpath(root, ext_dir)
1120         ext_build_dirs.append(build_dir)
1121         main.SConscript(joinpath(root, 'SConscript'),
1122                         variant_dir=joinpath(build_root, build_dir))
1123
1124 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1125 Export('gdb_xml_dir')
1126
1127 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1128
1129 ###################################################
1130 #
1131 # This builder and wrapper method are used to set up a directory with
1132 # switching headers. Those are headers which are in a generic location and
1133 # that include more specific headers from a directory chosen at build time
1134 # based on the current build settings.
1135 #
1136 ###################################################
1137
1138 def build_switching_header(target, source, env):
1139     path = str(target[0])
1140     subdir = str(source[0])
1141     dp, fp = os.path.split(path)
1142     dp = os.path.relpath(os.path.realpath(dp),
1143                          os.path.realpath(env['BUILDDIR']))
1144     with open(path, 'w') as hdr:
1145         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1146
1147 switching_header_action = MakeAction(build_switching_header,
1148                                      Transform('GENERATE'))
1149
1150 switching_header_builder = Builder(action=switching_header_action,
1151                                    source_factory=Value,
1152                                    single_source=True)
1153
1154 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1155
1156 def switching_headers(self, headers, source):
1157     for header in headers:
1158         self.SwitchingHeader(header, source)
1159
1160 main.AddMethod(switching_headers, 'SwitchingHeaders')
1161
1162 ###################################################
1163 #
1164 # Define build environments for selected configurations.
1165 #
1166 ###################################################
1167
1168 for variant_path in variant_paths:
1169     if not GetOption('silent'):
1170         print("Building in", variant_path)
1171
1172     # Make a copy of the build-root environment to use for this config.
1173     env = main.Clone()
1174     env['BUILDDIR'] = variant_path
1175
1176     # variant_dir is the tail component of build path, and is used to
1177     # determine the build parameters (e.g., 'ALPHA_SE')
1178     (build_root, variant_dir) = splitpath(variant_path)
1179
1180     # Set env variables according to the build directory config.
1181     sticky_vars.files = []
1182     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1183     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1184     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1185     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1186     if isfile(current_vars_file):
1187         sticky_vars.files.append(current_vars_file)
1188         if not GetOption('silent'):
1189             print("Using saved variables file %s" % current_vars_file)
1190     elif variant_dir in ext_build_dirs:
1191         # Things in ext are built without a variant directory.
1192         continue
1193     else:
1194         # Build dir-specific variables file doesn't exist.
1195
1196         # Make sure the directory is there so we can create it later
1197         opt_dir = dirname(current_vars_file)
1198         if not isdir(opt_dir):
1199             mkdir(opt_dir)
1200
1201         # Get default build variables from source tree.  Variables are
1202         # normally determined by name of $VARIANT_DIR, but can be
1203         # overridden by '--default=' arg on command line.
1204         default = GetOption('default')
1205         opts_dir = joinpath(main.root.abspath, 'build_opts')
1206         if default:
1207             default_vars_files = [joinpath(build_root, 'variables', default),
1208                                   joinpath(opts_dir, default)]
1209         else:
1210             default_vars_files = [joinpath(opts_dir, variant_dir)]
1211         existing_files = filter(isfile, default_vars_files)
1212         if existing_files:
1213             default_vars_file = existing_files[0]
1214             sticky_vars.files.append(default_vars_file)
1215             print("Variables file %s not found,\n  using defaults in %s"
1216                   % (current_vars_file, default_vars_file))
1217         else:
1218             error("Cannot find variables file %s or default file(s) %s"
1219                   % (current_vars_file, ' or '.join(default_vars_files)))
1220             Exit(1)
1221
1222     # Apply current variable settings to env
1223     sticky_vars.Update(env)
1224
1225     help_texts["local_vars"] += \
1226         "Build variables for %s:\n" % variant_dir \
1227                  + sticky_vars.GenerateHelpText(env)
1228
1229     # Process variable settings.
1230
1231     if not have_fenv and env['USE_FENV']:
1232         warning("<fenv.h> not available; forcing USE_FENV to False in",
1233                 variant_dir + ".")
1234         env['USE_FENV'] = False
1235
1236     if not env['USE_FENV']:
1237         warning("No IEEE FP rounding mode control in", variant_dir + ".\n"
1238                 "FP results may deviate slightly from other platforms.")
1239
1240     if not have_png and env['USE_PNG']:
1241         warning("<png.h> not available; forcing USE_PNG to False in",
1242                 variant_dir + ".")
1243         env['USE_PNG'] = False
1244
1245     if env['USE_PNG']:
1246         env.Append(LIBS=['png'])
1247
1248     if env['EFENCE']:
1249         env.Append(LIBS=['efence'])
1250
1251     if env['USE_KVM']:
1252         if not have_kvm:
1253             warning("Can not enable KVM, host seems to lack KVM support")
1254             env['USE_KVM'] = False
1255         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1256             print("Info: KVM support disabled due to unsupported host and "
1257                   "target ISA combination")
1258             env['USE_KVM'] = False
1259
1260     if env['USE_TUNTAP']:
1261         if not have_tuntap:
1262             warning("Can't connect EtherTap with a tap device.")
1263             env['USE_TUNTAP'] = False
1264
1265     if env['BUILD_GPU']:
1266         env.Append(CPPDEFINES=['BUILD_GPU'])
1267
1268     # Warn about missing optional functionality
1269     if env['USE_KVM']:
1270         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1271             warning("perf_event headers lack support for the exclude_host "
1272                     "attribute. KVM instruction counts will be inaccurate.")
1273
1274     # Save sticky variable settings back to current variables file
1275     sticky_vars.Save(current_vars_file, env)
1276
1277     if env['USE_SSE2']:
1278         env.Append(CCFLAGS=['-msse2'])
1279
1280     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1281     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1282
1283     # The src/SConscript file sets up the build rules in 'env' according
1284     # to the configured variables.  It returns a list of environments,
1285     # one for each variant build (debug, opt, etc.)
1286     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1287
1288 # base help text
1289 Help('''
1290 Usage: scons [scons options] [build variables] [target(s)]
1291
1292 Extra scons options:
1293 %(options)s
1294
1295 Global build variables:
1296 %(global_vars)s
1297
1298 %(local_vars)s
1299 ''' % help_texts)