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 if GetOption('no_lto') and GetOption('force_lto'):
 173     print('--no-lto and --force-lto are mutually exclusive')
 174     Exit(1)
 175
 176 ########################################################################
 177 #
 178 # Set up the main build environment.
 179 #
 180 ########################################################################
 181
 182 main = Environment()
 183
 184 from gem5_scons import Transform
 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     print("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 193     Exit(1)
 194
 195 ###################################################
 196 #
 197 # Figure out which configurations to set up based on the path(s) of
 198 # the target(s).
 199 #
 200 ###################################################
 201
 202 # Find default configuration & binary.
 203 Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
 204
 205 # helper function: find last occurrence of element in list
 206 def rfind(l, elt, offs = -1):
 207     for i in range(len(l)+offs, 0, -1):
 208         if l[i] == elt:
 209             return i
 210     raise ValueError, "element not found"
 211
 212 # Take a list of paths (or SCons Nodes) and return a list with all
 213 # paths made absolute and ~-expanded.  Paths will be interpreted
 214 # relative to the launch directory unless a different root is provided
 215 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 216     return [abspath(joinpath(root, expanduser(str(p))))
 217             for p in path_list]
 218
 219 def find_first_prog(prog_names):
 220     """Find the absolute path to the first existing binary in prog_names"""
 221
 222     if not isinstance(prog_names, (list, tuple)):
 223         prog_names = [ prog_names ]
 224
 225     for p in prog_names:
 226         p = main.WhereIs(p)
 227         if p is not None:
 228             return p
 229
 230     return None
 231
 232 # Each target must have 'build' in the interior of the path; the
 233 # directory below this will determine the build parameters.  For
 234 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 235 # recognize that ALPHA_SE specifies the configuration because it
 236 # follow 'build' in the build path.
 237
 238 # The funky assignment to "[:]" is needed to replace the list contents
 239 # in place rather than reassign the symbol to a new list, which
 240 # doesn't work (obviously!).
 241 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 242
 243 # Generate a list of the unique build roots and configs that the
 244 # collected targets reference.
 245 variant_paths = []
 246 build_root = None
 247 for t in BUILD_TARGETS:
 248     path_dirs = t.split('/')
 249     try:
 250         build_top = rfind(path_dirs, 'build', -2)
 251     except:
 252         print("Error: no non-leaf 'build' dir found on target path", t)
 253         Exit(1)
 254     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 255     if not build_root:
 256         build_root = this_build_root
 257     else:
 258         if this_build_root != build_root:
 259             print("Error: build targets not under same build root\n"
 260                   "  %s\n  %s" % (build_root, this_build_root))
 261             Exit(1)
 262     variant_path = joinpath('/',*path_dirs[:build_top+2])
 263     if variant_path not in variant_paths:
 264         variant_paths.append(variant_path)
 265
 266 # Make sure build_root exists (might not if this is the first build there)
 267 if not isdir(build_root):
 268     mkdir(build_root)
 269 main['BUILDROOT'] = build_root
 270
 271 Export('main')
 272
 273 main.SConsignFile(joinpath(build_root, "sconsign"))
 274
 275 # Default duplicate option is to use hard links, but this messes up
 276 # when you use emacs to edit a file in the target dir, as emacs moves
 277 # file to file~ then copies to file, breaking the link.  Symbolic
 278 # (soft) links work better.
 279 main.SetOption('duplicate', 'soft-copy')
 280
 281 #
 282 # Set up global sticky variables... these are common to an entire build
 283 # tree (not specific to a particular build like ALPHA_SE)
 284 #
 285
 286 global_vars_file = joinpath(build_root, 'variables.global')
 287
 288 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 289
 290 global_vars.AddVariables(
 291     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 292     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 293     ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
 294     ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
 295     ('PYTHON_CONFIG', 'Python config binary to use',
 296      [ 'python2.7-config', 'python-config' ]),
 297     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 298     ('BATCH', 'Use batch pool for build and tests', False),
 299     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 300     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 301     ('EXTRAS', 'Add extra directories to the compilation', '')
 302     )
 303
 304 # Update main environment with values from ARGUMENTS & global_vars_file
 305 global_vars.Update(main)
 306 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 307
 308 # Save sticky variable settings back to current variables file
 309 global_vars.Save(global_vars_file, main)
 310
 311 # Parse EXTRAS variable to build list of all directories where we're
 312 # look for sources etc.  This list is exported as extras_dir_list.
 313 base_dir = main.srcdir.abspath
 314 if main['EXTRAS']:
 315     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 316 else:
 317     extras_dir_list = []
 318
 319 Export('base_dir')
 320 Export('extras_dir_list')
 321
 322 # the ext directory should be on the #includes path
 323 main.Append(CPPPATH=[Dir('ext')])
 324
 325 # Add shared top-level headers
 326 main.Prepend(CPPPATH=Dir('include'))
 327
 328 if GetOption('verbose'):
 329     def MakeAction(action, string, *args, **kwargs):
 330         return Action(action, *args, **kwargs)
 331 else:
 332     MakeAction = Action
 333     main['CCCOMSTR']        = Transform("CC")
 334     main['CXXCOMSTR']       = Transform("CXX")
 335     main['ASCOMSTR']        = Transform("AS")
 336     main['ARCOMSTR']        = Transform("AR", 0)
 337     main['LINKCOMSTR']      = Transform("LINK", 0)
 338     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 339     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 340     main['M4COMSTR']        = Transform("M4")
 341     main['SHCCCOMSTR']      = Transform("SHCC")
 342     main['SHCXXCOMSTR']     = Transform("SHCXX")
 343 Export('MakeAction')
 344
 345 # Initialize the Link-Time Optimization (LTO) flags
 346 main['LTO_CCFLAGS'] = []
 347 main['LTO_LDFLAGS'] = []
 348
 349 # According to the readme, tcmalloc works best if the compiler doesn't
 350 # assume that we're using the builtin malloc and friends. These flags
 351 # are compiler-specific, so we need to set them after we detect which
 352 # compiler we're using.
 353 main['TCMALLOC_CCFLAGS'] = []
 354
 355 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 356 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 357
 358 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 359 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 360 if main['GCC'] + main['CLANG'] > 1:
 361     print('Error: How can we have two at the same time?')
 362     Exit(1)
 363
 364 # Set up default C++ compiler flags
 365 if main['GCC'] or main['CLANG']:
 366     # As gcc and clang share many flags, do the common parts here
 367     main.Append(CCFLAGS=['-pipe'])
 368     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 369     # Enable -Wall and -Wextra and then disable the few warnings that
 370     # we consistently violate
 371     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 372                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 373     # We always compile using C++11
 374     main.Append(CXXFLAGS=['-std=c++11'])
 375     if sys.platform.startswith('freebsd'):
 376         main.Append(CCFLAGS=['-I/usr/local/include'])
 377         main.Append(CXXFLAGS=['-I/usr/local/include'])
 378
 379     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 380     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 381     if GetOption('gold_linker'):
 382         main.Append(LINKFLAGS='-fuse-ld=gold')
 383     main['PLINKFLAGS'] = main.subst('${LINKFLAGS}')
 384     shared_partial_flags = ['-r', '-nostdlib']
 385     main.Append(PSHLINKFLAGS=shared_partial_flags)
 386     main.Append(PLINKFLAGS=shared_partial_flags)
 387
 388     # Treat warnings as errors but white list some warnings that we
 389     # want to allow (e.g., deprecation warnings).
 390     main.Append(CCFLAGS=['-Werror',
 391                          '-Wno-error=deprecated-declarations',
 392                          '-Wno-error=deprecated',
 393                         ])
 394 else:
 395     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 396     print("Don't know what compiler options to use for your compiler.")
 397     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 398     print(termcap.Yellow + '       version:' + termcap.Normal, end = ' ')
 399     if not CXX_version:
 400         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 401               termcap.Normal)
 402     else:
 403         print(CXX_version.replace('\n', '<nl>'))
 404     print("       If you're trying to use a compiler other than GCC")
 405     print("       or clang, there appears to be something wrong with your")
 406     print("       environment.")
 407     print("       ")
 408     print("       If you are trying to use a compiler other than those listed")
 409     print("       above you will need to ease fix SConstruct and ")
 410     print("       src/SConscript to support that compiler.")
 411     Exit(1)
 412
 413 if main['GCC']:
 414     # Check for a supported version of gcc. >= 4.8 is chosen for its
 415     # level of c++11 support. See
 416     # http://gcc.gnu.org/projects/cxx0x.html for details.
 417     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 418     if compareVersions(gcc_version, "4.8") < 0:
 419         print('Error: gcc version 4.8 or newer required.')
 420         print('       Installed version: ', gcc_version)
 421         Exit(1)
 422
 423     main['GCC_VERSION'] = gcc_version
 424
 425     if compareVersions(gcc_version, '4.9') >= 0:
 426         # Incremental linking with LTO is currently broken in gcc versions
 427         # 4.9 and above. A version where everything works completely hasn't
 428         # yet been identified.
 429         #
 430         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 431         main['BROKEN_INCREMENTAL_LTO'] = True
 432     if compareVersions(gcc_version, '6.0') >= 0:
 433         # gcc versions 6.0 and greater accept an -flinker-output flag which
 434         # selects what type of output the linker should generate. This is
 435         # necessary for incremental lto to work, but is also broken in
 436         # current versions of gcc. It may not be necessary in future
 437         # versions. We add it here since it might be, and as a reminder that
 438         # it exists. It's excluded if lto is being forced.
 439         #
 440         # https://gcc.gnu.org/gcc-6/changes.html
 441         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 442         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 443         if not GetOption('force_lto'):
 444             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 445             main.Append(PLINKFLAGS='-flinker-output=rel')
 446
 447     # Make sure we warn if the user has requested to compile with the
 448     # Undefined Benahvior Sanitizer and this version of gcc does not
 449     # support it.
 450     if GetOption('with_ubsan') and \
 451             compareVersions(gcc_version, '4.9') < 0:
 452         print(termcap.Yellow + termcap.Bold +
 453             'Warning: UBSan is only supported using gcc 4.9 and later.' +
 454             termcap.Normal)
 455
 456     disable_lto = GetOption('no_lto')
 457     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 458             not GetOption('force_lto'):
 459         print(termcap.Yellow + termcap.Bold +
 460             'Warning: Your compiler doesn\'t support incremental linking' +
 461             ' and lto at the same time, so lto is being disabled. To force' +
 462             ' lto on anyway, use the --force-lto option. That will disable' +
 463             ' partial linking.' +
 464             termcap.Normal)
 465         disable_lto = True
 466
 467     # Add the appropriate Link-Time Optimization (LTO) flags
 468     # unless LTO is explicitly turned off. Note that these flags
 469     # are only used by the fast target.
 470     if not disable_lto:
 471         # Pass the LTO flag when compiling to produce GIMPLE
 472         # output, we merely create the flags here and only append
 473         # them later
 474         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 475
 476         # Use the same amount of jobs for LTO as we are running
 477         # scons with
 478         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 479
 480     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 481                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 482
 483     # The address sanitizer is available for gcc >= 4.8
 484     if GetOption('with_asan'):
 485         if GetOption('with_ubsan') and \
 486                 compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 487             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 488                                  '-fno-omit-frame-pointer'],
 489                         LINKFLAGS='-fsanitize=address,undefined')
 490         else:
 491             main.Append(CCFLAGS=['-fsanitize=address',
 492                                  '-fno-omit-frame-pointer'],
 493                         LINKFLAGS='-fsanitize=address')
 494     # Only gcc >= 4.9 supports UBSan, so check both the version
 495     # and the command-line option before adding the compiler and
 496     # linker flags.
 497     elif GetOption('with_ubsan') and \
 498             compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 499         main.Append(CCFLAGS='-fsanitize=undefined')
 500         main.Append(LINKFLAGS='-fsanitize=undefined')
 501
 502 elif main['CLANG']:
 503     # Check for a supported version of clang, >= 3.1 is needed to
 504     # support similar features as gcc 4.8. See
 505     # http://clang.llvm.org/cxx_status.html for details
 506     clang_version_re = re.compile(".* version (\d+\.\d+)")
 507     clang_version_match = clang_version_re.search(CXX_version)
 508     if (clang_version_match):
 509         clang_version = clang_version_match.groups()[0]
 510         if compareVersions(clang_version, "3.1") < 0:
 511             print('Error: clang version 3.1 or newer required.')
 512             print('       Installed version:', clang_version)
 513             Exit(1)
 514     else:
 515         print('Error: Unable to determine clang version.')
 516         Exit(1)
 517
 518     # clang has a few additional warnings that we disable, extraneous
 519     # parantheses are allowed due to Ruby's printing of the AST,
 520     # finally self assignments are allowed as the generated CPU code
 521     # is relying on this
 522     main.Append(CCFLAGS=['-Wno-parentheses',
 523                          '-Wno-self-assign',
 524                          # Some versions of libstdc++ (4.8?) seem to
 525                          # use struct hash and class hash
 526                          # interchangeably.
 527                          '-Wno-mismatched-tags',
 528                          ])
 529
 530     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 531
 532     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 533     # opposed to libstdc++, as the later is dated.
 534     if sys.platform == "darwin":
 535         main.Append(CXXFLAGS=['-stdlib=libc++'])
 536         main.Append(LIBS=['c++'])
 537
 538     # On FreeBSD we need libthr.
 539     if sys.platform.startswith('freebsd'):
 540         main.Append(LIBS=['thr'])
 541
 542     # We require clang >= 3.1, so there is no need to check any
 543     # versions here.
 544     if GetOption('with_ubsan'):
 545         if GetOption('with_asan'):
 546             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 547                                  '-fno-omit-frame-pointer'],
 548                        LINKFLAGS='-fsanitize=address,undefined')
 549         else:
 550             main.Append(CCFLAGS='-fsanitize=undefined',
 551                         LINKFLAGS='-fsanitize=undefined')
 552
 553     elif GetOption('with_asan'):
 554         main.Append(CCFLAGS=['-fsanitize=address',
 555                              '-fno-omit-frame-pointer'],
 556                    LINKFLAGS='-fsanitize=address')
 557
 558 else:
 559     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 560     print("Don't know what compiler options to use for your compiler.")
 561     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 562     print(termcap.Yellow + '       version:' + termcap.Normal, end=' ')
 563     if not CXX_version:
 564         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 565               termcap.Normal)
 566     else:
 567         print(CXX_version.replace('\n', '<nl>'))
 568     print("       If you're trying to use a compiler other than GCC")
 569     print("       or clang, there appears to be something wrong with your")
 570     print("       environment.")
 571     print("       ")
 572     print("       If you are trying to use a compiler other than those listed")
 573     print("       above you will need to ease fix SConstruct and ")
 574     print("       src/SConscript to support that compiler.")
 575     Exit(1)
 576
 577 # Set up common yacc/bison flags (needed for Ruby)
 578 main['YACCFLAGS'] = '-d'
 579 main['YACCHXXFILESUFFIX'] = '.hh'
 580
 581 # Do this after we save setting back, or else we'll tack on an
 582 # extra 'qdo' every time we run scons.
 583 if main['BATCH']:
 584     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 585     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 586     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 587     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 588     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 589
 590 if sys.platform == 'cygwin':
 591     # cygwin has some header file issues...
 592     main.Append(CCFLAGS=["-Wno-uninitialized"])
 593
 594
 595 have_pkg_config = readCommand(['pkg-config', '--version'], exception='')
 596
 597 # Check for the protobuf compiler
 598 try:
 599     main['HAVE_PROTOC'] = True
 600     protoc_version = readCommand([main['PROTOC'], '--version']).split()
 601
 602     # First two words should be "libprotoc x.y.z"
 603     if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 604         print(termcap.Yellow + termcap.Bold +
 605             'Warning: Protocol buffer compiler (protoc) not found.\n' +
 606             '         Please install protobuf-compiler for tracing support.' +
 607             termcap.Normal)
 608         main['HAVE_PROTOC'] = False
 609     else:
 610         # Based on the availability of the compress stream wrappers,
 611         # require 2.1.0
 612         min_protoc_version = '2.1.0'
 613         if compareVersions(protoc_version[1], min_protoc_version) < 0:
 614             print(termcap.Yellow + termcap.Bold +
 615                 'Warning: protoc version', min_protoc_version,
 616                 'or newer required.\n' +
 617                 '         Installed version:', protoc_version[1],
 618                 termcap.Normal)
 619             main['HAVE_PROTOC'] = False
 620         else:
 621             # Attempt to determine the appropriate include path and
 622             # library path using pkg-config, that means we also need to
 623             # check for pkg-config. Note that it is possible to use
 624             # protobuf without the involvement of pkg-config. Later on we
 625             # check go a library config check and at that point the test
 626             # will fail if libprotobuf cannot be found.
 627             if have_pkg_config:
 628                 try:
 629                     # Attempt to establish what linking flags to add for
 630                     # protobuf
 631                     # using pkg-config
 632                     main.ParseConfig(
 633                             'pkg-config --cflags --libs-only-L protobuf')
 634                 except:
 635                     print(termcap.Yellow + termcap.Bold +
 636                         'Warning: pkg-config could not get protobuf flags.' +
 637                         termcap.Normal)
 638 except Exception as e:
 639     print(termcap.Yellow + termcap.Bold + str(e) + termcap.Normal)
 640     main['HAVE_PROTOC'] = False
 641
 642 # Check for 'timeout' from GNU coreutils. If present, regressions will
 643 # be run with a time limit. We require version 8.13 since we rely on
 644 # support for the '--foreground' option.
 645 if sys.platform.startswith('freebsd'):
 646     timeout_lines = readCommand(['gtimeout', '--version'],
 647                                 exception='').splitlines()
 648 else:
 649     timeout_lines = readCommand(['timeout', '--version'],
 650                                 exception='').splitlines()
 651 # Get the first line and tokenize it
 652 timeout_version = timeout_lines[0].split() if timeout_lines else []
 653 main['TIMEOUT'] =  timeout_version and \
 654     compareVersions(timeout_version[-1], '8.13') >= 0
 655
 656 # Add a custom Check function to test for structure members.
 657 def CheckMember(context, include, decl, member, include_quotes="<>"):
 658     context.Message("Checking for member %s in %s..." %
 659                     (member, decl))
 660     text = """
 661 #include %(header)s
 662 int main(){
 663   %(decl)s test;
 664   (void)test.%(member)s;
 665   return 0;
 666 };
 667 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 668         "decl" : decl,
 669         "member" : member,
 670         }
 671
 672     ret = context.TryCompile(text, extension=".cc")
 673     context.Result(ret)
 674     return ret
 675
 676 # Platform-specific configuration.  Note again that we assume that all
 677 # builds under a given build root run on the same host platform.
 678 conf = Configure(main,
 679                  conf_dir = joinpath(build_root, '.scons_config'),
 680                  log_file = joinpath(build_root, 'scons_config.log'),
 681                  custom_tests = {
 682         'CheckMember' : CheckMember,
 683         })
 684
 685 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 686 try:
 687     import platform
 688     uname = platform.uname()
 689     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 690         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 691             main.Append(CCFLAGS=['-arch', 'x86_64'])
 692             main.Append(CFLAGS=['-arch', 'x86_64'])
 693             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 694             main.Append(ASFLAGS=['-arch', 'x86_64'])
 695 except:
 696     pass
 697
 698 # Recent versions of scons substitute a "Null" object for Configure()
 699 # when configuration isn't necessary, e.g., if the "--help" option is
 700 # present.  Unfortuantely this Null object always returns false,
 701 # breaking all our configuration checks.  We replace it with our own
 702 # more optimistic null object that returns True instead.
 703 if not conf:
 704     def NullCheck(*args, **kwargs):
 705         return True
 706
 707     class NullConf:
 708         def __init__(self, env):
 709             self.env = env
 710         def Finish(self):
 711             return self.env
 712         def __getattr__(self, mname):
 713             return NullCheck
 714
 715     conf = NullConf(main)
 716
 717 # Cache build files in the supplied directory.
 718 if main['M5_BUILD_CACHE']:
 719     print('Using build cache located at', main['M5_BUILD_CACHE'])
 720     CacheDir(main['M5_BUILD_CACHE'])
 721
 722 main['USE_PYTHON'] = not GetOption('without_python')
 723 if main['USE_PYTHON']:
 724     # Find Python include and library directories for embedding the
 725     # interpreter. We rely on python-config to resolve the appropriate
 726     # includes and linker flags. ParseConfig does not seem to understand
 727     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 728     # we add them explicitly below. If you want to link in an alternate
 729     # version of python, see above for instructions on how to invoke
 730     # scons with the appropriate PATH set.
 731
 732     python_config = find_first_prog(main['PYTHON_CONFIG'])
 733     if python_config is None:
 734         print("Error: can't find a suitable python-config, tried %s" % \
 735               main['PYTHON_CONFIG'])
 736         Exit(1)
 737
 738     print("Info: Using Python config: %s" % (python_config, ))
 739     py_includes = readCommand([python_config, '--includes'],
 740                               exception='').split()
 741     py_includes = filter(lambda s: match(r'.*\/include\/.*',s), py_includes)
 742     # Strip the -I from the include folders before adding them to the
 743     # CPPPATH
 744     py_includes = map(lambda s: s[2:] if s.startswith('-I') else s, py_includes)
 745     main.Append(CPPPATH=py_includes)
 746
 747     # Read the linker flags and split them into libraries and other link
 748     # flags. The libraries are added later through the call the CheckLib.
 749     py_ld_flags = readCommand([python_config, '--ldflags'],
 750         exception='').split()
 751     py_libs = []
 752     for lib in py_ld_flags:
 753          if not lib.startswith('-l'):
 754              main.Append(LINKFLAGS=[lib])
 755          else:
 756              lib = lib[2:]
 757              if lib not in py_libs:
 758                  py_libs.append(lib)
 759
 760     # verify that this stuff works
 761     if not conf.CheckHeader('Python.h', '<>'):
 762         print("Error: Check failed for Python.h header in", py_includes)
 763         print("Two possible reasons:")
 764         print("1. Python headers are not installed (You can install the "
 765               "package python-dev on Ubuntu and RedHat)")
 766         print("2. SCons is using a wrong C compiler. This can happen if "
 767               "CC has the wrong value.")
 768         print("CC = %s" % main['CC'])
 769         Exit(1)
 770
 771     for lib in py_libs:
 772         if not conf.CheckLib(lib):
 773             print("Error: can't find library %s required by python" % lib)
 774             Exit(1)
 775
 776 # On Solaris you need to use libsocket for socket ops
 777 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 778    if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 779        print("Can't find library with socket calls (e.g. accept())")
 780        Exit(1)
 781
 782 # Check for zlib.  If the check passes, libz will be automatically
 783 # added to the LIBS environment variable.
 784 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 785     print('Error: did not find needed zlib compression library '
 786           'and/or zlib.h header file.')
 787     print('       Please install zlib and try again.')
 788     Exit(1)
 789
 790 # If we have the protobuf compiler, also make sure we have the
 791 # development libraries. If the check passes, libprotobuf will be
 792 # automatically added to the LIBS environment variable. After
 793 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 794 # got both protoc and libprotobuf available.
 795 main['HAVE_PROTOBUF'] = main['HAVE_PROTOC'] and \
 796     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 797                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 798
 799 # Valgrind gets much less confused if you tell it when you're using
 800 # alternative stacks.
 801 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 802
 803 # If we have the compiler but not the library, print another warning.
 804 if main['HAVE_PROTOC'] and not main['HAVE_PROTOBUF']:
 805     print(termcap.Yellow + termcap.Bold +
 806         'Warning: did not find protocol buffer library and/or headers.\n' +
 807     '       Please install libprotobuf-dev for tracing support.' +
 808     termcap.Normal)
 809
 810 # Check for librt.
 811 have_posix_clock = \
 812     conf.CheckLibWithHeader(None, 'time.h', 'C',
 813                             'clock_nanosleep(0,0,NULL,NULL);') or \
 814     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 815                             'clock_nanosleep(0,0,NULL,NULL);')
 816
 817 have_posix_timers = \
 818     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 819                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 820
 821 if not GetOption('without_tcmalloc'):
 822     if conf.CheckLib('tcmalloc'):
 823         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 824     elif conf.CheckLib('tcmalloc_minimal'):
 825         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 826     else:
 827         print(termcap.Yellow + termcap.Bold +
 828               "You can get a 12% performance improvement by "
 829               "installing tcmalloc (libgoogle-perftools-dev package "
 830               "on Ubuntu or RedHat)." + termcap.Normal)
 831
 832
 833 # Detect back trace implementations. The last implementation in the
 834 # list will be used by default.
 835 backtrace_impls = [ "none" ]
 836
 837 backtrace_checker = 'char temp;' + \
 838     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 839 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 840     backtrace_impls.append("glibc")
 841 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 842                              backtrace_checker):
 843     # NetBSD and FreeBSD need libexecinfo.
 844     backtrace_impls.append("glibc")
 845     main.Append(LIBS=['execinfo'])
 846
 847 if backtrace_impls[-1] == "none":
 848     default_backtrace_impl = "none"
 849     print(termcap.Yellow + termcap.Bold +
 850         "No suitable back trace implementation found." +
 851         termcap.Normal)
 852
 853 if not have_posix_clock:
 854     print("Can't find library for POSIX clocks.")
 855
 856 # Check for <fenv.h> (C99 FP environment control)
 857 have_fenv = conf.CheckHeader('fenv.h', '<>')
 858 if not have_fenv:
 859     print("Warning: Header file <fenv.h> not found.")
 860     print("         This host has no IEEE FP rounding mode control.")
 861
 862 # Check for <png.h> (libpng library needed if wanting to dump
 863 # frame buffer image in png format)
 864 have_png = conf.CheckHeader('png.h', '<>')
 865 if not have_png:
 866     print("Warning: Header file <png.h> not found.")
 867     print("         This host has no libpng library.")
 868     print("         Disabling support for PNG framebuffers.")
 869
 870 # Check if we should enable KVM-based hardware virtualization. The API
 871 # we rely on exists since version 2.6.36 of the kernel, but somehow
 872 # the KVM_API_VERSION does not reflect the change. We test for one of
 873 # the types as a fall back.
 874 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 875 if not have_kvm:
 876     print("Info: Compatible header file <linux/kvm.h> not found, "
 877           "disabling KVM support.")
 878
 879 # Check if the TUN/TAP driver is available.
 880 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 881 if not have_tuntap:
 882     print("Info: Compatible header file <linux/if_tun.h> not found.")
 883
 884 # x86 needs support for xsave. We test for the structure here since we
 885 # won't be able to run new tests by the time we know which ISA we're
 886 # targeting.
 887 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 888                                     '#include <linux/kvm.h>') != 0
 889
 890 # Check if the requested target ISA is compatible with the host
 891 def is_isa_kvm_compatible(isa):
 892     try:
 893         import platform
 894         host_isa = platform.machine()
 895     except:
 896         print("Warning: Failed to determine host ISA.")
 897         return False
 898
 899     if not have_posix_timers:
 900         print("Warning: Can not enable KVM, host seems to lack support "
 901               "for POSIX timers")
 902         return False
 903
 904     if isa == "arm":
 905         return host_isa in ( "armv7l", "aarch64" )
 906     elif isa == "x86":
 907         if host_isa != "x86_64":
 908             return False
 909
 910         if not have_kvm_xsave:
 911             print("KVM on x86 requires xsave support in kernel headers.")
 912             return False
 913
 914         return True
 915     else:
 916         return False
 917
 918
 919 # Check if the exclude_host attribute is available. We want this to
 920 # get accurate instruction counts in KVM.
 921 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 922     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 923
 924 def check_hdf5():
 925     return \
 926         conf.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
 927                                 'H5Fcreate("", 0, 0, 0);') and \
 928         conf.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
 929                                 'H5::H5File("", 0);')
 930
 931 def check_hdf5_pkg(name):
 932     print("Checking for %s using pkg-config..." % name, end="")
 933     if not have_pkg_config:
 934         print(" pkg-config not found")
 935         return False
 936
 937     try:
 938         main.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name)
 939         print(" yes")
 940         return True
 941     except:
 942         print(" no")
 943         return False
 944
 945 # Check if there is a pkg-config configuration for hdf5. If we find
 946 # it, setup the environment to enable linking and header inclusion. We
 947 # don't actually try to include any headers or link with hdf5 at this
 948 # stage.
 949 if not check_hdf5_pkg('hdf5-serial'):
 950     check_hdf5_pkg('hdf5')
 951
 952 # Check if the HDF5 libraries can be found. This check respects the
 953 # include path and library path provided by pkg-config. We perform
 954 # this check even if there isn't a pkg-config configuration for hdf5
 955 # since some installations don't use pkg-config.
 956 have_hdf5 = check_hdf5()
 957 if not have_hdf5:
 958     print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
 959     print("         HDF5 support.")
 960
 961 ######################################################################
 962 #
 963 # Finish the configuration
 964 #
 965 main = conf.Finish()
 966
 967 ######################################################################
 968 #
 969 # Collect all non-global variables
 970 #
 971
 972 # Define the universe of supported ISAs
 973 all_isa_list = [ ]
 974 all_gpu_isa_list = [ ]
 975 Export('all_isa_list')
 976 Export('all_gpu_isa_list')
 977
 978 class CpuModel(object):
 979     '''The CpuModel class encapsulates everything the ISA parser needs to
 980     know about a particular CPU model.'''
 981
 982     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 983     dict = {}
 984
 985     # Constructor.  Automatically adds models to CpuModel.dict.
 986     def __init__(self, name, default=False):
 987         self.name = name           # name of model
 988
 989         # This cpu is enabled by default
 990         self.default = default
 991
 992         # Add self to dict
 993         if name in CpuModel.dict:
 994             raise AttributeError, "CpuModel '%s' already registered" % name
 995         CpuModel.dict[name] = self
 996
 997 Export('CpuModel')
 998
 999 # Sticky variables get saved in the variables file so they persist from
1000 # one invocation to the next (unless overridden, in which case the new
1001 # value becomes sticky).
1002 sticky_vars = Variables(args=ARGUMENTS)
1003 Export('sticky_vars')
1004
1005 # Sticky variables that should be exported
1006 export_vars = []
1007 Export('export_vars')
1008
1009 # For Ruby
1010 all_protocols = []
1011 Export('all_protocols')
1012 protocol_dirs = []
1013 Export('protocol_dirs')
1014 slicc_includes = []
1015 Export('slicc_includes')
1016
1017 # Walk the tree and execute all SConsopts scripts that wil add to the
1018 # above variables
1019 if GetOption('verbose'):
1020     print("Reading SConsopts")
1021 for bdir in [ base_dir ] + extras_dir_list:
1022     if not isdir(bdir):
1023         print("Error: directory '%s' does not exist" % bdir)
1024         Exit(1)
1025     for root, dirs, files in os.walk(bdir):
1026         if 'SConsopts' in files:
1027             if GetOption('verbose'):
1028                 print("Reading", joinpath(root, 'SConsopts'))
1029             SConscript(joinpath(root, 'SConsopts'))
1030
1031 all_isa_list.sort()
1032 all_gpu_isa_list.sort()
1033
1034 sticky_vars.AddVariables(
1035     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1036     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
1037     ListVariable('CPU_MODELS', 'CPU models',
1038                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1039                  sorted(CpuModel.dict.keys())),
1040     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1041                  False),
1042     BoolVariable('SS_COMPATIBLE_FP',
1043                  'Make floating-point results compatible with SimpleScalar',
1044                  False),
1045     BoolVariable('USE_SSE2',
1046                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1047                  False),
1048     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1049     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1050     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
1051     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
1052                  False),
1053     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1054                  have_kvm),
1055     BoolVariable('USE_TUNTAP',
1056                  'Enable using a tap device to bridge to the host network',
1057                  have_tuntap),
1058     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1059     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1060                   all_protocols),
1061     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1062                  backtrace_impls[-1], backtrace_impls),
1063     ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1064                  64),
1065     BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5),
1066     )
1067
1068 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1069 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1070                 'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP',
1071                 'PROTOCOL', 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1072                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1073                 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1074
1075 ###################################################
1076 #
1077 # Define a SCons builder for configuration flag headers.
1078 #
1079 ###################################################
1080
1081 # This function generates a config header file that #defines the
1082 # variable symbol to the current variable setting (0 or 1).  The source
1083 # operands are the name of the variable and a Value node containing the
1084 # value of the variable.
1085 def build_config_file(target, source, env):
1086     (variable, value) = [s.get_contents() for s in source]
1087     f = file(str(target[0]), 'w')
1088     print('#define', variable, value, file=f)
1089     f.close()
1090     return None
1091
1092 # Combine the two functions into a scons Action object.
1093 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1094
1095 # The emitter munges the source & target node lists to reflect what
1096 # we're really doing.
1097 def config_emitter(target, source, env):
1098     # extract variable name from Builder arg
1099     variable = str(target[0])
1100     # True target is config header file
1101     target = joinpath('config', variable.lower() + '.hh')
1102     val = env[variable]
1103     if isinstance(val, bool):
1104         # Force value to 0/1
1105         val = int(val)
1106     elif isinstance(val, str):
1107         val = '"' + val + '"'
1108
1109     # Sources are variable name & value (packaged in SCons Value nodes)
1110     return ([target], [Value(variable), Value(val)])
1111
1112 config_builder = Builder(emitter = config_emitter, action = config_action)
1113
1114 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1115
1116 ###################################################
1117 #
1118 # Builders for static and shared partially linked object files.
1119 #
1120 ###################################################
1121
1122 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1123                                  src_suffix='$OBJSUFFIX',
1124                                  src_builder=['StaticObject', 'Object'],
1125                                  LINKFLAGS='$PLINKFLAGS',
1126                                  LIBS='')
1127
1128 def partial_shared_emitter(target, source, env):
1129     for tgt in target:
1130         tgt.attributes.shared = 1
1131     return (target, source)
1132 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1133                                  emitter=partial_shared_emitter,
1134                                  src_suffix='$SHOBJSUFFIX',
1135                                  src_builder='SharedObject',
1136                                  SHLINKFLAGS='$PSHLINKFLAGS',
1137                                  LIBS='')
1138
1139 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1140                          'PartialStatic' : partial_static_builder })
1141
1142 def add_local_rpath(env, *targets):
1143     '''Set up an RPATH for a library which lives in the build directory.
1144
1145     The construction environment variable BIN_RPATH_PREFIX should be set to
1146     the relative path of the build directory starting from the location of the
1147     binary.'''
1148     for target in targets:
1149         target = env.Entry(target)
1150         if not isinstance(target, SCons.Node.FS.Dir):
1151             target = target.dir
1152         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1153         components = [
1154             '\\$$ORIGIN',
1155             '${BIN_RPATH_PREFIX}',
1156             relpath
1157         ]
1158         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1159
1160 if sys.platform != "darwin":
1161     main.Append(LINKFLAGS=Split('-z origin'))
1162
1163 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1164
1165 # builds in ext are shared across all configs in the build root.
1166 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1167 ext_build_dirs = []
1168 for root, dirs, files in os.walk(ext_dir):
1169     if 'SConscript' in files:
1170         build_dir = os.path.relpath(root, ext_dir)
1171         ext_build_dirs.append(build_dir)
1172         main.SConscript(joinpath(root, 'SConscript'),
1173                         variant_dir=joinpath(build_root, build_dir))
1174
1175 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1176 Export('gdb_xml_dir')
1177
1178 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1179
1180 ###################################################
1181 #
1182 # This builder and wrapper method are used to set up a directory with
1183 # switching headers. Those are headers which are in a generic location and
1184 # that include more specific headers from a directory chosen at build time
1185 # based on the current build settings.
1186 #
1187 ###################################################
1188
1189 def build_switching_header(target, source, env):
1190     path = str(target[0])
1191     subdir = str(source[0])
1192     dp, fp = os.path.split(path)
1193     dp = os.path.relpath(os.path.realpath(dp),
1194                          os.path.realpath(env['BUILDDIR']))
1195     with open(path, 'w') as hdr:
1196         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1197
1198 switching_header_action = MakeAction(build_switching_header,
1199                                      Transform('GENERATE'))
1200
1201 switching_header_builder = Builder(action=switching_header_action,
1202                                    source_factory=Value,
1203                                    single_source=True)
1204
1205 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1206
1207 def switching_headers(self, headers, source):
1208     for header in headers:
1209         self.SwitchingHeader(header, source)
1210
1211 main.AddMethod(switching_headers, 'SwitchingHeaders')
1212
1213 ###################################################
1214 #
1215 # Define build environments for selected configurations.
1216 #
1217 ###################################################
1218
1219 for variant_path in variant_paths:
1220     if not GetOption('silent'):
1221         print("Building in", variant_path)
1222
1223     # Make a copy of the build-root environment to use for this config.
1224     env = main.Clone()
1225     env['BUILDDIR'] = variant_path
1226
1227     # variant_dir is the tail component of build path, and is used to
1228     # determine the build parameters (e.g., 'ALPHA_SE')
1229     (build_root, variant_dir) = splitpath(variant_path)
1230
1231     # Set env variables according to the build directory config.
1232     sticky_vars.files = []
1233     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1234     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1235     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1236     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1237     if isfile(current_vars_file):
1238         sticky_vars.files.append(current_vars_file)
1239         if not GetOption('silent'):
1240             print("Using saved variables file %s" % current_vars_file)
1241     elif variant_dir in ext_build_dirs:
1242         # Things in ext are built without a variant directory.
1243         continue
1244     else:
1245         # Build dir-specific variables file doesn't exist.
1246
1247         # Make sure the directory is there so we can create it later
1248         opt_dir = dirname(current_vars_file)
1249         if not isdir(opt_dir):
1250             mkdir(opt_dir)
1251
1252         # Get default build variables from source tree.  Variables are
1253         # normally determined by name of $VARIANT_DIR, but can be
1254         # overridden by '--default=' arg on command line.
1255         default = GetOption('default')
1256         opts_dir = joinpath(main.root.abspath, 'build_opts')
1257         if default:
1258             default_vars_files = [joinpath(build_root, 'variables', default),
1259                                   joinpath(opts_dir, default)]
1260         else:
1261             default_vars_files = [joinpath(opts_dir, variant_dir)]
1262         existing_files = filter(isfile, default_vars_files)
1263         if existing_files:
1264             default_vars_file = existing_files[0]
1265             sticky_vars.files.append(default_vars_file)
1266             print("Variables file %s not found,\n  using defaults in %s"
1267                   % (current_vars_file, default_vars_file))
1268         else:
1269             print("Error: cannot find variables file %s or "
1270                   "default file(s) %s"
1271                   % (current_vars_file, ' or '.join(default_vars_files)))
1272             Exit(1)
1273
1274     # Apply current variable settings to env
1275     sticky_vars.Update(env)
1276
1277     help_texts["local_vars"] += \
1278         "Build variables for %s:\n" % variant_dir \
1279                  + sticky_vars.GenerateHelpText(env)
1280
1281     # Process variable settings.
1282
1283     if not have_fenv and env['USE_FENV']:
1284         print("Warning: <fenv.h> not available; "
1285               "forcing USE_FENV to False in", variant_dir + ".")
1286         env['USE_FENV'] = False
1287
1288     if not env['USE_FENV']:
1289         print("Warning: No IEEE FP rounding mode control in",
1290               variant_dir + ".")
1291         print("         FP results may deviate slightly from other platforms.")
1292
1293     if not have_png and env['USE_PNG']:
1294         print("Warning: <png.h> not available; "
1295               "forcing USE_PNG to False in", variant_dir + ".")
1296         env['USE_PNG'] = False
1297
1298     if env['USE_PNG']:
1299         env.Append(LIBS=['png'])
1300
1301     if env['EFENCE']:
1302         env.Append(LIBS=['efence'])
1303
1304     if env['USE_KVM']:
1305         if not have_kvm:
1306             print("Warning: Can not enable KVM, host seems to "
1307                   "lack KVM support")
1308             env['USE_KVM'] = False
1309         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1310             print("Info: KVM support disabled due to unsupported host and "
1311                   "target ISA combination")
1312             env['USE_KVM'] = False
1313
1314     if env['USE_TUNTAP']:
1315         if not have_tuntap:
1316             print("Warning: Can't connect EtherTap with a tap device.")
1317             env['USE_TUNTAP'] = False
1318
1319     if env['BUILD_GPU']:
1320         env.Append(CPPDEFINES=['BUILD_GPU'])
1321
1322     # Warn about missing optional functionality
1323     if env['USE_KVM']:
1324         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1325             print("Warning: perf_event headers lack support for the "
1326                   "exclude_host attribute. KVM instruction counts will "
1327                   "be inaccurate.")
1328
1329     # Save sticky variable settings back to current variables file
1330     sticky_vars.Save(current_vars_file, env)
1331
1332     if env['USE_SSE2']:
1333         env.Append(CCFLAGS=['-msse2'])
1334
1335     env.Append(CCFLAGS='$CCFLAGS_EXTRA')
1336     env.Append(LINKFLAGS='$LDFLAGS_EXTRA')
1337
1338     # The src/SConscript file sets up the build rules in 'env' according
1339     # to the configured variables.  It returns a list of environments,
1340     # one for each variant build (debug, opt, etc.)
1341     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1342
1343 # base help text
1344 Help('''
1345 Usage: scons [scons options] [build variables] [target(s)]
1346
1347 Extra scons options:
1348 %(options)s
1349
1350 Global build variables:
1351 %(global_vars)s
1352
1353 %(local_vars)s
1354 ''' % help_texts)