SConstruct

   1 # -*- mode:python -*-
   2
   3 # Copyright (c) 2013, 2015-2017 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
 101 from m5.util import compareVersions, readCommand
 102
 103 help_texts = {
 104     "options" : "",
 105     "global_vars" : "",
 106     "local_vars" : ""
 107 }
 108
 109 Export("help_texts")
 110
 111
 112 # There's a bug in scons in that (1) by default, the help texts from
 113 # AddOption() are supposed to be displayed when you type 'scons -h'
 114 # and (2) you can override the help displayed by 'scons -h' using the
 115 # Help() function, but these two features are incompatible: once
 116 # you've overridden the help text using Help(), there's no way to get
 117 # at the help texts from AddOptions.  See:
 118 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 119 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 120 # This hack lets us extract the help text from AddOptions and
 121 # re-inject it via Help().  Ideally someday this bug will be fixed and
 122 # we can just use AddOption directly.
 123 def AddLocalOption(*args, **kwargs):
 124     col_width = 30
 125
 126     help = "  " + ", ".join(args)
 127     if "help" in kwargs:
 128         length = len(help)
 129         if length >= col_width:
 130             help += "\n" + " " * col_width
 131         else:
 132             help += " " * (col_width - length)
 133         help += kwargs["help"]
 134     help_texts["options"] += help + "\n"
 135
 136     AddOption(*args, **kwargs)
 137
 138 AddLocalOption('--colors', dest='use_colors', action='store_true',
 139                help="Add color to abbreviated scons output")
 140 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 141                help="Don't add color to abbreviated scons output")
 142 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 143                action='store_true',
 144                help="Build with support for C++-based configuration")
 145 AddLocalOption('--default', dest='default', type='string', action='store',
 146                help='Override which build_opts file to use for defaults')
 147 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 148                help='Disable style checking hooks')
 149 AddLocalOption('--gold-linker', dest='gold_linker', action='store_true',
 150                help='Use the gold linker')
 151 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 152                help='Disable Link-Time Optimization for fast')
 153 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 154                help='Use Link-Time Optimization instead of partial linking' +
 155                     ' when the compiler doesn\'t support using them together.')
 156 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 157                help='Update test reference outputs')
 158 AddLocalOption('--verbose', dest='verbose', action='store_true',
 159                help='Print full tool command lines')
 160 AddLocalOption('--without-python', dest='without_python',
 161                action='store_true',
 162                help='Build without Python configuration support')
 163 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 164                action='store_true',
 165                help='Disable linking against tcmalloc')
 166 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 167                help='Build with Undefined Behavior Sanitizer if available')
 168 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 169                help='Build with Address Sanitizer if available')
 170
 171 if GetOption('no_lto') and GetOption('force_lto'):
 172     print('--no-lto and --force-lto are mutually exclusive')
 173     Exit(1)
 174
 175 ########################################################################
 176 #
 177 # Set up the main build environment.
 178 #
 179 ########################################################################
 180
 181 main = Environment()
 182
 183 from gem5_scons import Transform
 184 from gem5_scons.util import get_termcap
 185 termcap = get_termcap()
 186
 187 main_dict_keys = main.Dictionary().keys()
 188
 189 # Check that we have a C/C++ compiler
 190 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 191     print("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 192     Exit(1)
 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 # Each target must have 'build' in the interior of the path; the
 219 # directory below this will determine the build parameters.  For
 220 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 221 # recognize that ALPHA_SE specifies the configuration because it
 222 # follow 'build' in the build path.
 223
 224 # The funky assignment to "[:]" is needed to replace the list contents
 225 # in place rather than reassign the symbol to a new list, which
 226 # doesn't work (obviously!).
 227 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 228
 229 # Generate a list of the unique build roots and configs that the
 230 # collected targets reference.
 231 variant_paths = []
 232 build_root = None
 233 for t in BUILD_TARGETS:
 234     path_dirs = t.split('/')
 235     try:
 236         build_top = rfind(path_dirs, 'build', -2)
 237     except:
 238         print("Error: no non-leaf 'build' dir found on target path", t)
 239         Exit(1)
 240     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 241     if not build_root:
 242         build_root = this_build_root
 243     else:
 244         if this_build_root != build_root:
 245             print("Error: build targets not under same build root\n"
 246                   "  %s\n  %s" % (build_root, this_build_root))
 247             Exit(1)
 248     variant_path = joinpath('/',*path_dirs[:build_top+2])
 249     if variant_path not in variant_paths:
 250         variant_paths.append(variant_path)
 251
 252 # Make sure build_root exists (might not if this is the first build there)
 253 if not isdir(build_root):
 254     mkdir(build_root)
 255 main['BUILDROOT'] = build_root
 256
 257 Export('main')
 258
 259 main.SConsignFile(joinpath(build_root, "sconsign"))
 260
 261 # Default duplicate option is to use hard links, but this messes up
 262 # when you use emacs to edit a file in the target dir, as emacs moves
 263 # file to file~ then copies to file, breaking the link.  Symbolic
 264 # (soft) links work better.
 265 main.SetOption('duplicate', 'soft-copy')
 266
 267 #
 268 # Set up global sticky variables... these are common to an entire build
 269 # tree (not specific to a particular build like ALPHA_SE)
 270 #
 271
 272 global_vars_file = joinpath(build_root, 'variables.global')
 273
 274 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 275
 276 global_vars.AddVariables(
 277     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 278     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 279     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 280     ('BATCH', 'Use batch pool for build and tests', False),
 281     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 282     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 283     ('EXTRAS', 'Add extra directories to the compilation', '')
 284     )
 285
 286 # Update main environment with values from ARGUMENTS & global_vars_file
 287 global_vars.Update(main)
 288 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 289
 290 # Save sticky variable settings back to current variables file
 291 global_vars.Save(global_vars_file, main)
 292
 293 # Parse EXTRAS variable to build list of all directories where we're
 294 # look for sources etc.  This list is exported as extras_dir_list.
 295 base_dir = main.srcdir.abspath
 296 if main['EXTRAS']:
 297     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 298 else:
 299     extras_dir_list = []
 300
 301 Export('base_dir')
 302 Export('extras_dir_list')
 303
 304 # the ext directory should be on the #includes path
 305 main.Append(CPPPATH=[Dir('ext')])
 306
 307 # Add shared top-level headers
 308 main.Prepend(CPPPATH=Dir('include'))
 309
 310 if GetOption('verbose'):
 311     def MakeAction(action, string, *args, **kwargs):
 312         return Action(action, *args, **kwargs)
 313 else:
 314     MakeAction = Action
 315     main['CCCOMSTR']        = Transform("CC")
 316     main['CXXCOMSTR']       = Transform("CXX")
 317     main['ASCOMSTR']        = Transform("AS")
 318     main['ARCOMSTR']        = Transform("AR", 0)
 319     main['LINKCOMSTR']      = Transform("LINK", 0)
 320     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 321     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 322     main['M4COMSTR']        = Transform("M4")
 323     main['SHCCCOMSTR']      = Transform("SHCC")
 324     main['SHCXXCOMSTR']     = Transform("SHCXX")
 325 Export('MakeAction')
 326
 327 # Initialize the Link-Time Optimization (LTO) flags
 328 main['LTO_CCFLAGS'] = []
 329 main['LTO_LDFLAGS'] = []
 330
 331 # According to the readme, tcmalloc works best if the compiler doesn't
 332 # assume that we're using the builtin malloc and friends. These flags
 333 # are compiler-specific, so we need to set them after we detect which
 334 # compiler we're using.
 335 main['TCMALLOC_CCFLAGS'] = []
 336
 337 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 338 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 339
 340 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 341 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 342 if main['GCC'] + main['CLANG'] > 1:
 343     print('Error: How can we have two at the same time?')
 344     Exit(1)
 345
 346 # Set up default C++ compiler flags
 347 if main['GCC'] or main['CLANG']:
 348     # As gcc and clang share many flags, do the common parts here
 349     main.Append(CCFLAGS=['-pipe'])
 350     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 351     # Enable -Wall and -Wextra and then disable the few warnings that
 352     # we consistently violate
 353     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 354                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 355     # We always compile using C++11
 356     main.Append(CXXFLAGS=['-std=c++11'])
 357     if sys.platform.startswith('freebsd'):
 358         main.Append(CCFLAGS=['-I/usr/local/include'])
 359         main.Append(CXXFLAGS=['-I/usr/local/include'])
 360
 361     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 362     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 363     if GetOption('gold_linker'):
 364         main.Append(LINKFLAGS='-fuse-ld=gold')
 365     main['PLINKFLAGS'] = main.subst('${LINKFLAGS}')
 366     shared_partial_flags = ['-r', '-nostdlib']
 367     main.Append(PSHLINKFLAGS=shared_partial_flags)
 368     main.Append(PLINKFLAGS=shared_partial_flags)
 369
 370     # Treat warnings as errors but white list some warnings that we
 371     # want to allow (e.g., deprecation warnings).
 372     main.Append(CCFLAGS=['-Werror',
 373                          '-Wno-error=deprecated-declarations',
 374                          '-Wno-error=deprecated',
 375                         ])
 376 else:
 377     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 378     print("Don't know what compiler options to use for your compiler.")
 379     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 380     print(termcap.Yellow + '       version:' + termcap.Normal, end = ' ')
 381     if not CXX_version:
 382         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 383               termcap.Normal)
 384     else:
 385         print(CXX_version.replace('\n', '<nl>'))
 386     print("       If you're trying to use a compiler other than GCC")
 387     print("       or clang, there appears to be something wrong with your")
 388     print("       environment.")
 389     print("       ")
 390     print("       If you are trying to use a compiler other than those listed")
 391     print("       above you will need to ease fix SConstruct and ")
 392     print("       src/SConscript to support that compiler.")
 393     Exit(1)
 394
 395 if main['GCC']:
 396     # Check for a supported version of gcc. >= 4.8 is chosen for its
 397     # level of c++11 support. See
 398     # http://gcc.gnu.org/projects/cxx0x.html for details.
 399     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 400     if compareVersions(gcc_version, "4.8") < 0:
 401         print('Error: gcc version 4.8 or newer required.')
 402         print('       Installed version: ', gcc_version)
 403         Exit(1)
 404
 405     main['GCC_VERSION'] = gcc_version
 406
 407     if compareVersions(gcc_version, '4.9') >= 0:
 408         # Incremental linking with LTO is currently broken in gcc versions
 409         # 4.9 and above. A version where everything works completely hasn't
 410         # yet been identified.
 411         #
 412         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 413         main['BROKEN_INCREMENTAL_LTO'] = True
 414     if compareVersions(gcc_version, '6.0') >= 0:
 415         # gcc versions 6.0 and greater accept an -flinker-output flag which
 416         # selects what type of output the linker should generate. This is
 417         # necessary for incremental lto to work, but is also broken in
 418         # current versions of gcc. It may not be necessary in future
 419         # versions. We add it here since it might be, and as a reminder that
 420         # it exists. It's excluded if lto is being forced.
 421         #
 422         # https://gcc.gnu.org/gcc-6/changes.html
 423         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 424         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 425         if not GetOption('force_lto'):
 426             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 427             main.Append(PLINKFLAGS='-flinker-output=rel')
 428
 429     # Make sure we warn if the user has requested to compile with the
 430     # Undefined Benahvior Sanitizer and this version of gcc does not
 431     # support it.
 432     if GetOption('with_ubsan') and \
 433             compareVersions(gcc_version, '4.9') < 0:
 434         print(termcap.Yellow + termcap.Bold +
 435             'Warning: UBSan is only supported using gcc 4.9 and later.' +
 436             termcap.Normal)
 437
 438     disable_lto = GetOption('no_lto')
 439     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 440             not GetOption('force_lto'):
 441         print(termcap.Yellow + termcap.Bold +
 442             'Warning: Your compiler doesn\'t support incremental linking' +
 443             ' and lto at the same time, so lto is being disabled. To force' +
 444             ' lto on anyway, use the --force-lto option. That will disable' +
 445             ' partial linking.' +
 446             termcap.Normal)
 447         disable_lto = True
 448
 449     # Add the appropriate Link-Time Optimization (LTO) flags
 450     # unless LTO is explicitly turned off. Note that these flags
 451     # are only used by the fast target.
 452     if not disable_lto:
 453         # Pass the LTO flag when compiling to produce GIMPLE
 454         # output, we merely create the flags here and only append
 455         # them later
 456         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 457
 458         # Use the same amount of jobs for LTO as we are running
 459         # scons with
 460         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 461
 462     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 463                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 464
 465     # The address sanitizer is available for gcc >= 4.8
 466     if GetOption('with_asan'):
 467         if GetOption('with_ubsan') and \
 468                 compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 469             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 470                                  '-fno-omit-frame-pointer'],
 471                         LINKFLAGS='-fsanitize=address,undefined')
 472         else:
 473             main.Append(CCFLAGS=['-fsanitize=address',
 474                                  '-fno-omit-frame-pointer'],
 475                         LINKFLAGS='-fsanitize=address')
 476     # Only gcc >= 4.9 supports UBSan, so check both the version
 477     # and the command-line option before adding the compiler and
 478     # linker flags.
 479     elif GetOption('with_ubsan') and \
 480             compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 481         main.Append(CCFLAGS='-fsanitize=undefined')
 482         main.Append(LINKFLAGS='-fsanitize=undefined')
 483
 484 elif main['CLANG']:
 485     # Check for a supported version of clang, >= 3.1 is needed to
 486     # support similar features as gcc 4.8. See
 487     # http://clang.llvm.org/cxx_status.html for details
 488     clang_version_re = re.compile(".* version (\d+\.\d+)")
 489     clang_version_match = clang_version_re.search(CXX_version)
 490     if (clang_version_match):
 491         clang_version = clang_version_match.groups()[0]
 492         if compareVersions(clang_version, "3.1") < 0:
 493             print('Error: clang version 3.1 or newer required.')
 494             print('       Installed version:', clang_version)
 495             Exit(1)
 496     else:
 497         print('Error: Unable to determine clang version.')
 498         Exit(1)
 499
 500     # clang has a few additional warnings that we disable, extraneous
 501     # parantheses are allowed due to Ruby's printing of the AST,
 502     # finally self assignments are allowed as the generated CPU code
 503     # is relying on this
 504     main.Append(CCFLAGS=['-Wno-parentheses',
 505                          '-Wno-self-assign',
 506                          # Some versions of libstdc++ (4.8?) seem to
 507                          # use struct hash and class hash
 508                          # interchangeably.
 509                          '-Wno-mismatched-tags',
 510                          ])
 511
 512     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 513
 514     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 515     # opposed to libstdc++, as the later is dated.
 516     if sys.platform == "darwin":
 517         main.Append(CXXFLAGS=['-stdlib=libc++'])
 518         main.Append(LIBS=['c++'])
 519
 520     # On FreeBSD we need libthr.
 521     if sys.platform.startswith('freebsd'):
 522         main.Append(LIBS=['thr'])
 523
 524     # We require clang >= 3.1, so there is no need to check any
 525     # versions here.
 526     if GetOption('with_ubsan'):
 527         if GetOption('with_asan'):
 528             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 529                                  '-fno-omit-frame-pointer'],
 530                        LINKFLAGS='-fsanitize=address,undefined')
 531         else:
 532             main.Append(CCFLAGS='-fsanitize=undefined',
 533                         LINKFLAGS='-fsanitize=undefined')
 534
 535     elif GetOption('with_asan'):
 536         main.Append(CCFLAGS=['-fsanitize=address',
 537                              '-fno-omit-frame-pointer'],
 538                    LINKFLAGS='-fsanitize=address')
 539
 540 else:
 541     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 542     print("Don't know what compiler options to use for your compiler.")
 543     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 544     print(termcap.Yellow + '       version:' + termcap.Normal, end=' ')
 545     if not CXX_version:
 546         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 547               termcap.Normal)
 548     else:
 549         print(CXX_version.replace('\n', '<nl>'))
 550     print("       If you're trying to use a compiler other than GCC")
 551     print("       or clang, there appears to be something wrong with your")
 552     print("       environment.")
 553     print("       ")
 554     print("       If you are trying to use a compiler other than those listed")
 555     print("       above you will need to ease fix SConstruct and ")
 556     print("       src/SConscript to support that compiler.")
 557     Exit(1)
 558
 559 # Set up common yacc/bison flags (needed for Ruby)
 560 main['YACCFLAGS'] = '-d'
 561 main['YACCHXXFILESUFFIX'] = '.hh'
 562
 563 # Do this after we save setting back, or else we'll tack on an
 564 # extra 'qdo' every time we run scons.
 565 if main['BATCH']:
 566     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 567     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 568     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 569     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 570     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 571
 572 if sys.platform == 'cygwin':
 573     # cygwin has some header file issues...
 574     main.Append(CCFLAGS=["-Wno-uninitialized"])
 575
 576 # Check for the protobuf compiler
 577 protoc_version = readCommand([main['PROTOC'], '--version'],
 578                              exception='').split()
 579
 580 # First two words should be "libprotoc x.y.z"
 581 if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 582     print(termcap.Yellow + termcap.Bold +
 583         'Warning: Protocol buffer compiler (protoc) not found.\n' +
 584         '         Please install protobuf-compiler for tracing support.' +
 585         termcap.Normal)
 586     main['PROTOC'] = False
 587 else:
 588     # Based on the availability of the compress stream wrappers,
 589     # require 2.1.0
 590     min_protoc_version = '2.1.0'
 591     if compareVersions(protoc_version[1], min_protoc_version) < 0:
 592         print(termcap.Yellow + termcap.Bold +
 593             'Warning: protoc version', min_protoc_version,
 594             'or newer required.\n' +
 595             '         Installed version:', protoc_version[1],
 596             termcap.Normal)
 597         main['PROTOC'] = False
 598     else:
 599         # Attempt to determine the appropriate include path and
 600         # library path using pkg-config, that means we also need to
 601         # check for pkg-config. Note that it is possible to use
 602         # protobuf without the involvement of pkg-config. Later on we
 603         # check go a library config check and at that point the test
 604         # will fail if libprotobuf cannot be found.
 605         if readCommand(['pkg-config', '--version'], exception=''):
 606             try:
 607                 # Attempt to establish what linking flags to add for protobuf
 608                 # using pkg-config
 609                 main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
 610             except:
 611                 print(termcap.Yellow + termcap.Bold +
 612                     'Warning: pkg-config could not get protobuf flags.' +
 613                     termcap.Normal)
 614
 615
 616 # Check for 'timeout' from GNU coreutils. If present, regressions will
 617 # be run with a time limit. We require version 8.13 since we rely on
 618 # support for the '--foreground' option.
 619 if sys.platform.startswith('freebsd'):
 620     timeout_lines = readCommand(['gtimeout', '--version'],
 621                                 exception='').splitlines()
 622 else:
 623     timeout_lines = readCommand(['timeout', '--version'],
 624                                 exception='').splitlines()
 625 # Get the first line and tokenize it
 626 timeout_version = timeout_lines[0].split() if timeout_lines else []
 627 main['TIMEOUT'] =  timeout_version and \
 628     compareVersions(timeout_version[-1], '8.13') >= 0
 629
 630 # Add a custom Check function to test for structure members.
 631 def CheckMember(context, include, decl, member, include_quotes="<>"):
 632     context.Message("Checking for member %s in %s..." %
 633                     (member, decl))
 634     text = """
 635 #include %(header)s
 636 int main(){
 637   %(decl)s test;
 638   (void)test.%(member)s;
 639   return 0;
 640 };
 641 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 642         "decl" : decl,
 643         "member" : member,
 644         }
 645
 646     ret = context.TryCompile(text, extension=".cc")
 647     context.Result(ret)
 648     return ret
 649
 650 # Platform-specific configuration.  Note again that we assume that all
 651 # builds under a given build root run on the same host platform.
 652 conf = Configure(main,
 653                  conf_dir = joinpath(build_root, '.scons_config'),
 654                  log_file = joinpath(build_root, 'scons_config.log'),
 655                  custom_tests = {
 656         'CheckMember' : CheckMember,
 657         })
 658
 659 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 660 try:
 661     import platform
 662     uname = platform.uname()
 663     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 664         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 665             main.Append(CCFLAGS=['-arch', 'x86_64'])
 666             main.Append(CFLAGS=['-arch', 'x86_64'])
 667             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 668             main.Append(ASFLAGS=['-arch', 'x86_64'])
 669 except:
 670     pass
 671
 672 # Recent versions of scons substitute a "Null" object for Configure()
 673 # when configuration isn't necessary, e.g., if the "--help" option is
 674 # present.  Unfortuantely this Null object always returns false,
 675 # breaking all our configuration checks.  We replace it with our own
 676 # more optimistic null object that returns True instead.
 677 if not conf:
 678     def NullCheck(*args, **kwargs):
 679         return True
 680
 681     class NullConf:
 682         def __init__(self, env):
 683             self.env = env
 684         def Finish(self):
 685             return self.env
 686         def __getattr__(self, mname):
 687             return NullCheck
 688
 689     conf = NullConf(main)
 690
 691 # Cache build files in the supplied directory.
 692 if main['M5_BUILD_CACHE']:
 693     print('Using build cache located at', main['M5_BUILD_CACHE'])
 694     CacheDir(main['M5_BUILD_CACHE'])
 695
 696 main['USE_PYTHON'] = not GetOption('without_python')
 697 if main['USE_PYTHON']:
 698     # Find Python include and library directories for embedding the
 699     # interpreter. We rely on python-config to resolve the appropriate
 700     # includes and linker flags. ParseConfig does not seem to understand
 701     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 702     # we add them explicitly below. If you want to link in an alternate
 703     # version of python, see above for instructions on how to invoke
 704     # scons with the appropriate PATH set.
 705     #
 706     # First we check if python2-config exists, else we use python-config
 707     python_config = readCommand(['which', 'python2-config'],
 708                                 exception='').strip()
 709     if not os.path.exists(python_config):
 710         python_config = readCommand(['which', 'python-config'],
 711                                     exception='').strip()
 712     py_includes = readCommand([python_config, '--includes'],
 713                               exception='').split()
 714     py_includes = filter(lambda s: match(r'.*\/include\/.*',s), py_includes)
 715     # Strip the -I from the include folders before adding them to the
 716     # CPPPATH
 717     py_includes = map(lambda s: s[2:] if s.startswith('-I') else s, py_includes)
 718     main.Append(CPPPATH=py_includes)
 719
 720     # Read the linker flags and split them into libraries and other link
 721     # flags. The libraries are added later through the call the CheckLib.
 722     py_ld_flags = readCommand([python_config, '--ldflags'],
 723         exception='').split()
 724     py_libs = []
 725     for lib in py_ld_flags:
 726          if not lib.startswith('-l'):
 727              main.Append(LINKFLAGS=[lib])
 728          else:
 729              lib = lib[2:]
 730              if lib not in py_libs:
 731                  py_libs.append(lib)
 732
 733     # verify that this stuff works
 734     if not conf.CheckHeader('Python.h', '<>'):
 735         print("Error: Check failed for Python.h header in", py_includes)
 736         print("Two possible reasons:")
 737         print("1. Python headers are not installed (You can install the "
 738               "package python-dev on Ubuntu and RedHat)")
 739         print("2. SCons is using a wrong C compiler. This can happen if "
 740               "CC has the wrong value.")
 741         print("CC = %s" % main['CC'])
 742         Exit(1)
 743
 744     for lib in py_libs:
 745         if not conf.CheckLib(lib):
 746             print("Error: can't find library %s required by python" % lib)
 747             Exit(1)
 748
 749 # On Solaris you need to use libsocket for socket ops
 750 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 751    if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 752        print("Can't find library with socket calls (e.g. accept())")
 753        Exit(1)
 754
 755 # Check for zlib.  If the check passes, libz will be automatically
 756 # added to the LIBS environment variable.
 757 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 758     print('Error: did not find needed zlib compression library '
 759           'and/or zlib.h header file.')
 760     print('       Please install zlib and try again.')
 761     Exit(1)
 762
 763 # If we have the protobuf compiler, also make sure we have the
 764 # development libraries. If the check passes, libprotobuf will be
 765 # automatically added to the LIBS environment variable. After
 766 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 767 # got both protoc and libprotobuf available.
 768 main['HAVE_PROTOBUF'] = main['PROTOC'] and \
 769     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 770                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 771
 772 # Valgrind gets much less confused if you tell it when you're using
 773 # alternative stacks.
 774 main['HAVE_VALGRIND'] = conf.CheckCHeader('valgrind/valgrind.h')
 775
 776 # If we have the compiler but not the library, print another warning.
 777 if main['PROTOC'] and not main['HAVE_PROTOBUF']:
 778     print(termcap.Yellow + termcap.Bold +
 779         'Warning: did not find protocol buffer library and/or headers.\n' +
 780     '       Please install libprotobuf-dev for tracing support.' +
 781     termcap.Normal)
 782
 783 # Check for librt.
 784 have_posix_clock = \
 785     conf.CheckLibWithHeader(None, 'time.h', 'C',
 786                             'clock_nanosleep(0,0,NULL,NULL);') or \
 787     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 788                             'clock_nanosleep(0,0,NULL,NULL);')
 789
 790 have_posix_timers = \
 791     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 792                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 793
 794 if not GetOption('without_tcmalloc'):
 795     if conf.CheckLib('tcmalloc'):
 796         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 797     elif conf.CheckLib('tcmalloc_minimal'):
 798         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 799     else:
 800         print(termcap.Yellow + termcap.Bold +
 801               "You can get a 12% performance improvement by "
 802               "installing tcmalloc (libgoogle-perftools-dev package "
 803               "on Ubuntu or RedHat)." + termcap.Normal)
 804
 805
 806 # Detect back trace implementations. The last implementation in the
 807 # list will be used by default.
 808 backtrace_impls = [ "none" ]
 809
 810 backtrace_checker = 'char temp;' + \
 811     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 812 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 813     backtrace_impls.append("glibc")
 814 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 815                              backtrace_checker):
 816     # NetBSD and FreeBSD need libexecinfo.
 817     backtrace_impls.append("glibc")
 818     main.Append(LIBS=['execinfo'])
 819
 820 if backtrace_impls[-1] == "none":
 821     default_backtrace_impl = "none"
 822     print(termcap.Yellow + termcap.Bold +
 823         "No suitable back trace implementation found." +
 824         termcap.Normal)
 825
 826 if not have_posix_clock:
 827     print("Can't find library for POSIX clocks.")
 828
 829 # Check for <fenv.h> (C99 FP environment control)
 830 have_fenv = conf.CheckHeader('fenv.h', '<>')
 831 if not have_fenv:
 832     print("Warning: Header file <fenv.h> not found.")
 833     print("         This host has no IEEE FP rounding mode control.")
 834
 835 # Check for <png.h> (libpng library needed if wanting to dump
 836 # frame buffer image in png format)
 837 have_png = conf.CheckHeader('png.h', '<>')
 838 if not have_png:
 839     print("Warning: Header file <png.h> not found.")
 840     print("         This host has no libpng library.")
 841     print("         Disabling support for PNG framebuffers.")
 842
 843 # Check if we should enable KVM-based hardware virtualization. The API
 844 # we rely on exists since version 2.6.36 of the kernel, but somehow
 845 # the KVM_API_VERSION does not reflect the change. We test for one of
 846 # the types as a fall back.
 847 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 848 if not have_kvm:
 849     print("Info: Compatible header file <linux/kvm.h> not found, "
 850           "disabling KVM support.")
 851
 852 # Check if the TUN/TAP driver is available.
 853 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 854 if not have_tuntap:
 855     print("Info: Compatible header file <linux/if_tun.h> not found.")
 856
 857 # x86 needs support for xsave. We test for the structure here since we
 858 # won't be able to run new tests by the time we know which ISA we're
 859 # targeting.
 860 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 861                                     '#include <linux/kvm.h>') != 0
 862
 863 # Check if the requested target ISA is compatible with the host
 864 def is_isa_kvm_compatible(isa):
 865     try:
 866         import platform
 867         host_isa = platform.machine()
 868     except:
 869         print("Warning: Failed to determine host ISA.")
 870         return False
 871
 872     if not have_posix_timers:
 873         print("Warning: Can not enable KVM, host seems to lack support "
 874               "for POSIX timers")
 875         return False
 876
 877     if isa == "arm":
 878         return host_isa in ( "armv7l", "aarch64" )
 879     elif isa == "x86":
 880         if host_isa != "x86_64":
 881             return False
 882
 883         if not have_kvm_xsave:
 884             print("KVM on x86 requires xsave support in kernel headers.")
 885             return False
 886
 887         return True
 888     else:
 889         return False
 890
 891
 892 # Check if the exclude_host attribute is available. We want this to
 893 # get accurate instruction counts in KVM.
 894 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 895     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 896
 897
 898 ######################################################################
 899 #
 900 # Finish the configuration
 901 #
 902 main = conf.Finish()
 903
 904 ######################################################################
 905 #
 906 # Collect all non-global variables
 907 #
 908
 909 # Define the universe of supported ISAs
 910 all_isa_list = [ ]
 911 all_gpu_isa_list = [ ]
 912 Export('all_isa_list')
 913 Export('all_gpu_isa_list')
 914
 915 class CpuModel(object):
 916     '''The CpuModel class encapsulates everything the ISA parser needs to
 917     know about a particular CPU model.'''
 918
 919     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 920     dict = {}
 921
 922     # Constructor.  Automatically adds models to CpuModel.dict.
 923     def __init__(self, name, default=False):
 924         self.name = name           # name of model
 925
 926         # This cpu is enabled by default
 927         self.default = default
 928
 929         # Add self to dict
 930         if name in CpuModel.dict:
 931             raise AttributeError, "CpuModel '%s' already registered" % name
 932         CpuModel.dict[name] = self
 933
 934 Export('CpuModel')
 935
 936 # Sticky variables get saved in the variables file so they persist from
 937 # one invocation to the next (unless overridden, in which case the new
 938 # value becomes sticky).
 939 sticky_vars = Variables(args=ARGUMENTS)
 940 Export('sticky_vars')
 941
 942 # Sticky variables that should be exported
 943 export_vars = []
 944 Export('export_vars')
 945
 946 # For Ruby
 947 all_protocols = []
 948 Export('all_protocols')
 949 protocol_dirs = []
 950 Export('protocol_dirs')
 951 slicc_includes = []
 952 Export('slicc_includes')
 953
 954 # Walk the tree and execute all SConsopts scripts that wil add to the
 955 # above variables
 956 if GetOption('verbose'):
 957     print("Reading SConsopts")
 958 for bdir in [ base_dir ] + extras_dir_list:
 959     if not isdir(bdir):
 960         print("Error: directory '%s' does not exist" % bdir)
 961         Exit(1)
 962     for root, dirs, files in os.walk(bdir):
 963         if 'SConsopts' in files:
 964             if GetOption('verbose'):
 965                 print("Reading", joinpath(root, 'SConsopts'))
 966             SConscript(joinpath(root, 'SConsopts'))
 967
 968 all_isa_list.sort()
 969 all_gpu_isa_list.sort()
 970
 971 sticky_vars.AddVariables(
 972     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 973     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 974     ListVariable('CPU_MODELS', 'CPU models',
 975                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
 976                  sorted(CpuModel.dict.keys())),
 977     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 978                  False),
 979     BoolVariable('SS_COMPATIBLE_FP',
 980                  'Make floating-point results compatible with SimpleScalar',
 981                  False),
 982     BoolVariable('USE_SSE2',
 983                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 984                  False),
 985     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 986     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 987     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 988     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
 989                  False),
 990     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 991                  have_kvm),
 992     BoolVariable('USE_TUNTAP',
 993                  'Enable using a tap device to bridge to the host network',
 994                  have_tuntap),
 995     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
 996     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
 997                   all_protocols),
 998     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
 999                  backtrace_impls[-1], backtrace_impls)
1000     )
1001
1002 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1003 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1004                 'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP',
1005                 'PROTOCOL', 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1006                 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG']
1007
1008 ###################################################
1009 #
1010 # Define a SCons builder for configuration flag headers.
1011 #
1012 ###################################################
1013
1014 # This function generates a config header file that #defines the
1015 # variable symbol to the current variable setting (0 or 1).  The source
1016 # operands are the name of the variable and a Value node containing the
1017 # value of the variable.
1018 def build_config_file(target, source, env):
1019     (variable, value) = [s.get_contents() for s in source]
1020     f = file(str(target[0]), 'w')
1021     print('#define', variable, value, file=f)
1022     f.close()
1023     return None
1024
1025 # Combine the two functions into a scons Action object.
1026 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1027
1028 # The emitter munges the source & target node lists to reflect what
1029 # we're really doing.
1030 def config_emitter(target, source, env):
1031     # extract variable name from Builder arg
1032     variable = str(target[0])
1033     # True target is config header file
1034     target = joinpath('config', variable.lower() + '.hh')
1035     val = env[variable]
1036     if isinstance(val, bool):
1037         # Force value to 0/1
1038         val = int(val)
1039     elif isinstance(val, str):
1040         val = '"' + val + '"'
1041
1042     # Sources are variable name & value (packaged in SCons Value nodes)
1043     return ([target], [Value(variable), Value(val)])
1044
1045 config_builder = Builder(emitter = config_emitter, action = config_action)
1046
1047 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1048
1049 ###################################################
1050 #
1051 # Builders for static and shared partially linked object files.
1052 #
1053 ###################################################
1054
1055 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1056                                  src_suffix='$OBJSUFFIX',
1057                                  src_builder=['StaticObject', 'Object'],
1058                                  LINKFLAGS='$PLINKFLAGS',
1059                                  LIBS='')
1060
1061 def partial_shared_emitter(target, source, env):
1062     for tgt in target:
1063         tgt.attributes.shared = 1
1064     return (target, source)
1065 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1066                                  emitter=partial_shared_emitter,
1067                                  src_suffix='$SHOBJSUFFIX',
1068                                  src_builder='SharedObject',
1069                                  SHLINKFLAGS='$PSHLINKFLAGS',
1070                                  LIBS='')
1071
1072 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1073                          'PartialStatic' : partial_static_builder })
1074
1075 def add_local_rpath(env, *targets):
1076     '''Set up an RPATH for a library which lives in the build directory.
1077
1078     The construction environment variable BIN_RPATH_PREFIX should be set to
1079     the relative path of the build directory starting from the location of the
1080     binary.'''
1081     for target in targets:
1082         target = env.Entry(target)
1083         if not target.isdir():
1084             target = target.dir
1085         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
1086         components = [
1087             '\\$$ORIGIN',
1088             '${BIN_RPATH_PREFIX}',
1089             relpath
1090         ]
1091         env.Append(RPATH=[env.Literal(os.path.join(*components))])
1092
1093 main.Append(LINKFLAGS=Split('-z origin'))
1094 main.AddMethod(add_local_rpath, 'AddLocalRPATH')
1095
1096 # builds in ext are shared across all configs in the build root.
1097 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1098 ext_build_dirs = []
1099 for root, dirs, files in os.walk(ext_dir):
1100     if 'SConscript' in files:
1101         build_dir = os.path.relpath(root, ext_dir)
1102         ext_build_dirs.append(build_dir)
1103         main.SConscript(joinpath(root, 'SConscript'),
1104                         variant_dir=joinpath(build_root, build_dir))
1105
1106 gdb_xml_dir = joinpath(ext_dir, 'gdb-xml')
1107 Export('gdb_xml_dir')
1108
1109 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1110
1111 ###################################################
1112 #
1113 # This builder and wrapper method are used to set up a directory with
1114 # switching headers. Those are headers which are in a generic location and
1115 # that include more specific headers from a directory chosen at build time
1116 # based on the current build settings.
1117 #
1118 ###################################################
1119
1120 def build_switching_header(target, source, env):
1121     path = str(target[0])
1122     subdir = str(source[0])
1123     dp, fp = os.path.split(path)
1124     dp = os.path.relpath(os.path.realpath(dp),
1125                          os.path.realpath(env['BUILDDIR']))
1126     with open(path, 'w') as hdr:
1127         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1128
1129 switching_header_action = MakeAction(build_switching_header,
1130                                      Transform('GENERATE'))
1131
1132 switching_header_builder = Builder(action=switching_header_action,
1133                                    source_factory=Value,
1134                                    single_source=True)
1135
1136 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1137
1138 def switching_headers(self, headers, source):
1139     for header in headers:
1140         self.SwitchingHeader(header, source)
1141
1142 main.AddMethod(switching_headers, 'SwitchingHeaders')
1143
1144 ###################################################
1145 #
1146 # Define build environments for selected configurations.
1147 #
1148 ###################################################
1149
1150 for variant_path in variant_paths:
1151     if not GetOption('silent'):
1152         print("Building in", variant_path)
1153
1154     # Make a copy of the build-root environment to use for this config.
1155     env = main.Clone()
1156     env['BUILDDIR'] = variant_path
1157
1158     # variant_dir is the tail component of build path, and is used to
1159     # determine the build parameters (e.g., 'ALPHA_SE')
1160     (build_root, variant_dir) = splitpath(variant_path)
1161
1162     # Set env variables according to the build directory config.
1163     sticky_vars.files = []
1164     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1165     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1166     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1167     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1168     if isfile(current_vars_file):
1169         sticky_vars.files.append(current_vars_file)
1170         if not GetOption('silent'):
1171             print("Using saved variables file %s" % current_vars_file)
1172     elif variant_dir in ext_build_dirs:
1173         # Things in ext are built without a variant directory.
1174         continue
1175     else:
1176         # Build dir-specific variables file doesn't exist.
1177
1178         # Make sure the directory is there so we can create it later
1179         opt_dir = dirname(current_vars_file)
1180         if not isdir(opt_dir):
1181             mkdir(opt_dir)
1182
1183         # Get default build variables from source tree.  Variables are
1184         # normally determined by name of $VARIANT_DIR, but can be
1185         # overridden by '--default=' arg on command line.
1186         default = GetOption('default')
1187         opts_dir = joinpath(main.root.abspath, 'build_opts')
1188         if default:
1189             default_vars_files = [joinpath(build_root, 'variables', default),
1190                                   joinpath(opts_dir, default)]
1191         else:
1192             default_vars_files = [joinpath(opts_dir, variant_dir)]
1193         existing_files = filter(isfile, default_vars_files)
1194         if existing_files:
1195             default_vars_file = existing_files[0]
1196             sticky_vars.files.append(default_vars_file)
1197             print("Variables file %s not found,\n  using defaults in %s"
1198                   % (current_vars_file, default_vars_file))
1199         else:
1200             print("Error: cannot find variables file %s or "
1201                   "default file(s) %s"
1202                   % (current_vars_file, ' or '.join(default_vars_files)))
1203             Exit(1)
1204
1205     # Apply current variable settings to env
1206     sticky_vars.Update(env)
1207
1208     help_texts["local_vars"] += \
1209         "Build variables for %s:\n" % variant_dir \
1210                  + sticky_vars.GenerateHelpText(env)
1211
1212     # Process variable settings.
1213
1214     if not have_fenv and env['USE_FENV']:
1215         print("Warning: <fenv.h> not available; "
1216               "forcing USE_FENV to False in", variant_dir + ".")
1217         env['USE_FENV'] = False
1218
1219     if not env['USE_FENV']:
1220         print("Warning: No IEEE FP rounding mode control in",
1221               variant_dir + ".")
1222         print("         FP results may deviate slightly from other platforms.")
1223
1224     if not have_png and env['USE_PNG']:
1225         print("Warning: <png.h> not available; "
1226               "forcing USE_PNG to False in", variant_dir + ".")
1227         env['USE_PNG'] = False
1228
1229     if env['USE_PNG']:
1230         env.Append(LIBS=['png'])
1231
1232     if env['EFENCE']:
1233         env.Append(LIBS=['efence'])
1234
1235     if env['USE_KVM']:
1236         if not have_kvm:
1237             print("Warning: Can not enable KVM, host seems to "
1238                   "lack KVM support")
1239             env['USE_KVM'] = False
1240         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1241             print("Info: KVM support disabled due to unsupported host and "
1242                   "target ISA combination")
1243             env['USE_KVM'] = False
1244
1245     if env['USE_TUNTAP']:
1246         if not have_tuntap:
1247             print("Warning: Can't connect EtherTap with a tap device.")
1248             env['USE_TUNTAP'] = False
1249
1250     if env['BUILD_GPU']:
1251         env.Append(CPPDEFINES=['BUILD_GPU'])
1252
1253     # Warn about missing optional functionality
1254     if env['USE_KVM']:
1255         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1256             print("Warning: perf_event headers lack support for the "
1257                   "exclude_host attribute. KVM instruction counts will "
1258                   "be inaccurate.")
1259
1260     # Save sticky variable settings back to current variables file
1261     sticky_vars.Save(current_vars_file, env)
1262
1263     if env['USE_SSE2']:
1264         env.Append(CCFLAGS=['-msse2'])
1265
1266     # The src/SConscript file sets up the build rules in 'env' according
1267     # to the configured variables.  It returns a list of environments,
1268     # one for each variant build (debug, opt, etc.)
1269     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1270
1271 # base help text
1272 Help('''
1273 Usage: scons [scons options] [build variables] [target(s)]
1274
1275 Extra scons options:
1276 %(options)s
1277
1278 Global build variables:
1279 %(global_vars)s
1280
1281 %(local_vars)s
1282 ''' % help_texts)