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 # Global Python includes
  82 import itertools
  83 import os
  84 import re
  85 import shutil
  86 import subprocess
  87 import sys
  88
  89 from os import mkdir, environ
  90 from os.path import abspath, basename, dirname, expanduser, normpath
  91 from os.path import exists,  isdir, isfile
  92 from os.path import join as joinpath, split as splitpath
  93
  94 # SCons includes
  95 import SCons
  96 import SCons.Node
  97
  98 from m5.util import compareVersions, readCommand
  99
 100 help_texts = {
 101     "options" : "",
 102     "global_vars" : "",
 103     "local_vars" : ""
 104 }
 105
 106 Export("help_texts")
 107
 108
 109 # There's a bug in scons in that (1) by default, the help texts from
 110 # AddOption() are supposed to be displayed when you type 'scons -h'
 111 # and (2) you can override the help displayed by 'scons -h' using the
 112 # Help() function, but these two features are incompatible: once
 113 # you've overridden the help text using Help(), there's no way to get
 114 # at the help texts from AddOptions.  See:
 115 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 116 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 117 # This hack lets us extract the help text from AddOptions and
 118 # re-inject it via Help().  Ideally someday this bug will be fixed and
 119 # we can just use AddOption directly.
 120 def AddLocalOption(*args, **kwargs):
 121     col_width = 30
 122
 123     help = "  " + ", ".join(args)
 124     if "help" in kwargs:
 125         length = len(help)
 126         if length >= col_width:
 127             help += "\n" + " " * col_width
 128         else:
 129             help += " " * (col_width - length)
 130         help += kwargs["help"]
 131     help_texts["options"] += help + "\n"
 132
 133     AddOption(*args, **kwargs)
 134
 135 AddLocalOption('--colors', dest='use_colors', action='store_true',
 136                help="Add color to abbreviated scons output")
 137 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 138                help="Don't add color to abbreviated scons output")
 139 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 140                action='store_true',
 141                help="Build with support for C++-based configuration")
 142 AddLocalOption('--default', dest='default', type='string', action='store',
 143                help='Override which build_opts file to use for defaults')
 144 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 145                help='Disable style checking hooks')
 146 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 147                help='Disable Link-Time Optimization for fast')
 148 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 149                help='Use Link-Time Optimization instead of partial linking' +
 150                     ' when the compiler doesn\'t support using them together.')
 151 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 152                help='Update test reference outputs')
 153 AddLocalOption('--verbose', dest='verbose', action='store_true',
 154                help='Print full tool command lines')
 155 AddLocalOption('--without-python', dest='without_python',
 156                action='store_true',
 157                help='Build without Python configuration support')
 158 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 159                action='store_true',
 160                help='Disable linking against tcmalloc')
 161 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 162                help='Build with Undefined Behavior Sanitizer if available')
 163 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 164                help='Build with Address Sanitizer if available')
 165
 166 if GetOption('no_lto') and GetOption('force_lto'):
 167     print '--no-lto and --force-lto are mutually exclusive'
 168     Exit(1)
 169
 170 ########################################################################
 171 #
 172 # Set up the main build environment.
 173 #
 174 ########################################################################
 175
 176 main = Environment()
 177
 178 from gem5_scons import Transform
 179 from gem5_scons.util import get_termcap
 180 termcap = get_termcap()
 181
 182 main_dict_keys = main.Dictionary().keys()
 183
 184 # Check that we have a C/C++ compiler
 185 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 186     print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
 187     Exit(1)
 188
 189 ###################################################
 190 #
 191 # Figure out which configurations to set up based on the path(s) of
 192 # the target(s).
 193 #
 194 ###################################################
 195
 196 # Find default configuration & binary.
 197 Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
 198
 199 # helper function: find last occurrence of element in list
 200 def rfind(l, elt, offs = -1):
 201     for i in range(len(l)+offs, 0, -1):
 202         if l[i] == elt:
 203             return i
 204     raise ValueError, "element not found"
 205
 206 # Take a list of paths (or SCons Nodes) and return a list with all
 207 # paths made absolute and ~-expanded.  Paths will be interpreted
 208 # relative to the launch directory unless a different root is provided
 209 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 210     return [abspath(joinpath(root, expanduser(str(p))))
 211             for p in path_list]
 212
 213 # Each target must have 'build' in the interior of the path; the
 214 # directory below this will determine the build parameters.  For
 215 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 216 # recognize that ALPHA_SE specifies the configuration because it
 217 # follow 'build' in the build path.
 218
 219 # The funky assignment to "[:]" is needed to replace the list contents
 220 # in place rather than reassign the symbol to a new list, which
 221 # doesn't work (obviously!).
 222 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 223
 224 # Generate a list of the unique build roots and configs that the
 225 # collected targets reference.
 226 variant_paths = []
 227 build_root = None
 228 for t in BUILD_TARGETS:
 229     path_dirs = t.split('/')
 230     try:
 231         build_top = rfind(path_dirs, 'build', -2)
 232     except:
 233         print "Error: no non-leaf 'build' dir found on target path", t
 234         Exit(1)
 235     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 236     if not build_root:
 237         build_root = this_build_root
 238     else:
 239         if this_build_root != build_root:
 240             print "Error: build targets not under same build root\n"\
 241                   "  %s\n  %s" % (build_root, this_build_root)
 242             Exit(1)
 243     variant_path = joinpath('/',*path_dirs[:build_top+2])
 244     if variant_path not in variant_paths:
 245         variant_paths.append(variant_path)
 246
 247 # Make sure build_root exists (might not if this is the first build there)
 248 if not isdir(build_root):
 249     mkdir(build_root)
 250 main['BUILDROOT'] = build_root
 251
 252 Export('main')
 253
 254 main.SConsignFile(joinpath(build_root, "sconsign"))
 255
 256 # Default duplicate option is to use hard links, but this messes up
 257 # when you use emacs to edit a file in the target dir, as emacs moves
 258 # file to file~ then copies to file, breaking the link.  Symbolic
 259 # (soft) links work better.
 260 main.SetOption('duplicate', 'soft-copy')
 261
 262 #
 263 # Set up global sticky variables... these are common to an entire build
 264 # tree (not specific to a particular build like ALPHA_SE)
 265 #
 266
 267 global_vars_file = joinpath(build_root, 'variables.global')
 268
 269 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 270
 271 global_vars.AddVariables(
 272     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 273     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 274     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 275     ('BATCH', 'Use batch pool for build and tests', False),
 276     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 277     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 278     ('EXTRAS', 'Add extra directories to the compilation', '')
 279     )
 280
 281 # Update main environment with values from ARGUMENTS & global_vars_file
 282 global_vars.Update(main)
 283 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 284
 285 # Save sticky variable settings back to current variables file
 286 global_vars.Save(global_vars_file, main)
 287
 288 # Parse EXTRAS variable to build list of all directories where we're
 289 # look for sources etc.  This list is exported as extras_dir_list.
 290 base_dir = main.srcdir.abspath
 291 if main['EXTRAS']:
 292     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 293 else:
 294     extras_dir_list = []
 295
 296 Export('base_dir')
 297 Export('extras_dir_list')
 298
 299 # the ext directory should be on the #includes path
 300 main.Append(CPPPATH=[Dir('ext')])
 301
 302 # Add shared top-level headers
 303 main.Prepend(CPPPATH=Dir('include'))
 304
 305 if GetOption('verbose'):
 306     def MakeAction(action, string, *args, **kwargs):
 307         return Action(action, *args, **kwargs)
 308 else:
 309     MakeAction = Action
 310     main['CCCOMSTR']        = Transform("CC")
 311     main['CXXCOMSTR']       = Transform("CXX")
 312     main['ASCOMSTR']        = Transform("AS")
 313     main['ARCOMSTR']        = Transform("AR", 0)
 314     main['LINKCOMSTR']      = Transform("LINK", 0)
 315     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 316     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 317     main['M4COMSTR']        = Transform("M4")
 318     main['SHCCCOMSTR']      = Transform("SHCC")
 319     main['SHCXXCOMSTR']     = Transform("SHCXX")
 320 Export('MakeAction')
 321
 322 # Initialize the Link-Time Optimization (LTO) flags
 323 main['LTO_CCFLAGS'] = []
 324 main['LTO_LDFLAGS'] = []
 325
 326 # According to the readme, tcmalloc works best if the compiler doesn't
 327 # assume that we're using the builtin malloc and friends. These flags
 328 # are compiler-specific, so we need to set them after we detect which
 329 # compiler we're using.
 330 main['TCMALLOC_CCFLAGS'] = []
 331
 332 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 333 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 334
 335 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 336 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 337 if main['GCC'] + main['CLANG'] > 1:
 338     print 'Error: How can we have two at the same time?'
 339     Exit(1)
 340
 341 # Set up default C++ compiler flags
 342 if main['GCC'] or main['CLANG']:
 343     # As gcc and clang share many flags, do the common parts here
 344     main.Append(CCFLAGS=['-pipe'])
 345     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 346     # Enable -Wall and -Wextra and then disable the few warnings that
 347     # we consistently violate
 348     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 349                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 350     # We always compile using C++11
 351     main.Append(CXXFLAGS=['-std=c++11'])
 352     if sys.platform.startswith('freebsd'):
 353         main.Append(CCFLAGS=['-I/usr/local/include'])
 354         main.Append(CXXFLAGS=['-I/usr/local/include'])
 355
 356     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 357     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 358     main['PLINKFLAGS'] = main.subst('${LINKFLAGS}')
 359     shared_partial_flags = ['-r', '-nostdlib']
 360     main.Append(PSHLINKFLAGS=shared_partial_flags)
 361     main.Append(PLINKFLAGS=shared_partial_flags)
 362
 363     # Treat warnings as errors but white list some warnings that we
 364     # want to allow (e.g., deprecation warnings).
 365     main.Append(CCFLAGS=['-Werror',
 366                          '-Wno-error=deprecated-declarations',
 367                          '-Wno-error=deprecated',
 368                         ])
 369 else:
 370     print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
 371     print "Don't know what compiler options to use for your compiler."
 372     print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
 373     print termcap.Yellow + '       version:' + termcap.Normal,
 374     if not CXX_version:
 375         print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
 376                termcap.Normal
 377     else:
 378         print CXX_version.replace('\n', '<nl>')
 379     print "       If you're trying to use a compiler other than GCC"
 380     print "       or clang, there appears to be something wrong with your"
 381     print "       environment."
 382     print "       "
 383     print "       If you are trying to use a compiler other than those listed"
 384     print "       above you will need to ease fix SConstruct and "
 385     print "       src/SConscript to support that compiler."
 386     Exit(1)
 387
 388 if main['GCC']:
 389     # Check for a supported version of gcc. >= 4.8 is chosen for its
 390     # level of c++11 support. See
 391     # http://gcc.gnu.org/projects/cxx0x.html for details.
 392     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 393     if compareVersions(gcc_version, "4.8") < 0:
 394         print 'Error: gcc version 4.8 or newer required.'
 395         print '       Installed version:', gcc_version
 396         Exit(1)
 397
 398     main['GCC_VERSION'] = gcc_version
 399
 400     if compareVersions(gcc_version, '4.9') >= 0:
 401         # Incremental linking with LTO is currently broken in gcc versions
 402         # 4.9 and above. A version where everything works completely hasn't
 403         # yet been identified.
 404         #
 405         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 406         main['BROKEN_INCREMENTAL_LTO'] = True
 407     if compareVersions(gcc_version, '6.0') >= 0:
 408         # gcc versions 6.0 and greater accept an -flinker-output flag which
 409         # selects what type of output the linker should generate. This is
 410         # necessary for incremental lto to work, but is also broken in
 411         # current versions of gcc. It may not be necessary in future
 412         # versions. We add it here since it might be, and as a reminder that
 413         # it exists. It's excluded if lto is being forced.
 414         #
 415         # https://gcc.gnu.org/gcc-6/changes.html
 416         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 417         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 418         if not GetOption('force_lto'):
 419             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 420             main.Append(PLINKFLAGS='-flinker-output=rel')
 421
 422     # gcc from version 4.8 and above generates "rep; ret" instructions
 423     # to avoid performance penalties on certain AMD chips. Older
 424     # assemblers detect this as an error, "Error: expecting string
 425     # instruction after `rep'"
 426     as_version_raw = readCommand([main['AS'], '-v', '/dev/null',
 427                                   '-o', '/dev/null'],
 428                                  exception=False).split()
 429
 430     # version strings may contain extra distro-specific
 431     # qualifiers, so play it safe and keep only what comes before
 432     # the first hyphen
 433     as_version = as_version_raw[-1].split('-')[0] if as_version_raw else None
 434
 435     if not as_version or compareVersions(as_version, "2.23") < 0:
 436         print termcap.Yellow + termcap.Bold + \
 437             'Warning: This combination of gcc and binutils have' + \
 438             ' known incompatibilities.\n' + \
 439             '         If you encounter build problems, please update ' + \
 440             'binutils to 2.23.' + \
 441             termcap.Normal
 442
 443     # Make sure we warn if the user has requested to compile with the
 444     # Undefined Benahvior Sanitizer and this version of gcc does not
 445     # support it.
 446     if GetOption('with_ubsan') and \
 447             compareVersions(gcc_version, '4.9') < 0:
 448         print termcap.Yellow + termcap.Bold + \
 449             'Warning: UBSan is only supported using gcc 4.9 and later.' + \
 450             termcap.Normal
 451
 452     disable_lto = GetOption('no_lto')
 453     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 454             not GetOption('force_lto'):
 455         print termcap.Yellow + termcap.Bold + \
 456             'Warning: Your compiler doesn\'t support incremental linking' + \
 457             ' and lto at the same time, so lto is being disabled. To force' + \
 458             ' lto on anyway, use the --force-lto option. That will disable' + \
 459             ' partial linking.' + \
 460             termcap.Normal
 461         disable_lto = True
 462
 463     # Add the appropriate Link-Time Optimization (LTO) flags
 464     # unless LTO is explicitly turned off. Note that these flags
 465     # are only used by the fast target.
 466     if not disable_lto:
 467         # Pass the LTO flag when compiling to produce GIMPLE
 468         # output, we merely create the flags here and only append
 469         # them later
 470         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 471
 472         # Use the same amount of jobs for LTO as we are running
 473         # scons with
 474         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 475
 476     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 477                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 478
 479     # add option to check for undeclared overrides
 480     if compareVersions(gcc_version, "5.0") > 0:
 481         main.Append(CCFLAGS=['-Wno-error=suggest-override'])
 482
 483     # The address sanitizer is available for gcc >= 4.8
 484     if GetOption('with_asan'):
 485         if GetOption('with_ubsan') and \
 486                 compareVersions(env['GCC_VERSION'], '4.9') >= 0:
 487             env.Append(CCFLAGS=['-fsanitize=address,undefined',
 488                                 '-fno-omit-frame-pointer'],
 489                        LINKFLAGS='-fsanitize=address,undefined')
 490         else:
 491             env.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(env['GCC_VERSION'], '4.9') >= 0:
 499         env.Append(CCFLAGS='-fsanitize=undefined')
 500         env.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             env.Append(CCFLAGS=['-fsanitize=address,undefined',
 547                                 '-fno-omit-frame-pointer'],
 548                        LINKFLAGS='-fsanitize=address,undefined')
 549         else:
 550             env.Append(CCFLAGS='-fsanitize=undefined',
 551                        LINKFLAGS='-fsanitize=undefined')
 552
 553     elif GetOption('with_asan'):
 554         env.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,
 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,
 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 # Check for the protobuf compiler
 595 protoc_version = readCommand([main['PROTOC'], '--version'],
 596                              exception='').split()
 597
 598 # First two words should be "libprotoc x.y.z"
 599 if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 600     print termcap.Yellow + termcap.Bold + \
 601         'Warning: Protocol buffer compiler (protoc) not found.\n' + \
 602         '         Please install protobuf-compiler for tracing support.' + \
 603         termcap.Normal
 604     main['PROTOC'] = False
 605 else:
 606     # Based on the availability of the compress stream wrappers,
 607     # require 2.1.0
 608     min_protoc_version = '2.1.0'
 609     if compareVersions(protoc_version[1], min_protoc_version) < 0:
 610         print termcap.Yellow + termcap.Bold + \
 611             'Warning: protoc version', min_protoc_version, \
 612             'or newer required.\n' + \
 613             '         Installed version:', protoc_version[1], \
 614             termcap.Normal
 615         main['PROTOC'] = False
 616     else:
 617         # Attempt to determine the appropriate include path and
 618         # library path using pkg-config, that means we also need to
 619         # check for pkg-config. Note that it is possible to use
 620         # protobuf without the involvement of pkg-config. Later on we
 621         # check go a library config check and at that point the test
 622         # will fail if libprotobuf cannot be found.
 623         if readCommand(['pkg-config', '--version'], exception=''):
 624             try:
 625                 # Attempt to establish what linking flags to add for protobuf
 626                 # using pkg-config
 627                 main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
 628             except:
 629                 print termcap.Yellow + termcap.Bold + \
 630                     'Warning: pkg-config could not get protobuf flags.' + \
 631                     termcap.Normal
 632
 633
 634 # Check for 'timeout' from GNU coreutils. If present, regressions will
 635 # be run with a time limit. We require version 8.13 since we rely on
 636 # support for the '--foreground' option.
 637 if sys.platform.startswith('freebsd'):
 638     timeout_lines = readCommand(['gtimeout', '--version'],
 639                                 exception='').splitlines()
 640 else:
 641     timeout_lines = readCommand(['timeout', '--version'],
 642                                 exception='').splitlines()
 643 # Get the first line and tokenize it
 644 timeout_version = timeout_lines[0].split() if timeout_lines else []
 645 main['TIMEOUT'] =  timeout_version and \
 646     compareVersions(timeout_version[-1], '8.13') >= 0
 647
 648 # Add a custom Check function to test for structure members.
 649 def CheckMember(context, include, decl, member, include_quotes="<>"):
 650     context.Message("Checking for member %s in %s..." %
 651                     (member, decl))
 652     text = """
 653 #include %(header)s
 654 int main(){
 655   %(decl)s test;
 656   (void)test.%(member)s;
 657   return 0;
 658 };
 659 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 660         "decl" : decl,
 661         "member" : member,
 662         }
 663
 664     ret = context.TryCompile(text, extension=".cc")
 665     context.Result(ret)
 666     return ret
 667
 668 # Platform-specific configuration.  Note again that we assume that all
 669 # builds under a given build root run on the same host platform.
 670 conf = Configure(main,
 671                  conf_dir = joinpath(build_root, '.scons_config'),
 672                  log_file = joinpath(build_root, 'scons_config.log'),
 673                  custom_tests = {
 674         'CheckMember' : CheckMember,
 675         })
 676
 677 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 678 try:
 679     import platform
 680     uname = platform.uname()
 681     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 682         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 683             main.Append(CCFLAGS=['-arch', 'x86_64'])
 684             main.Append(CFLAGS=['-arch', 'x86_64'])
 685             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 686             main.Append(ASFLAGS=['-arch', 'x86_64'])
 687 except:
 688     pass
 689
 690 # Recent versions of scons substitute a "Null" object for Configure()
 691 # when configuration isn't necessary, e.g., if the "--help" option is
 692 # present.  Unfortuantely this Null object always returns false,
 693 # breaking all our configuration checks.  We replace it with our own
 694 # more optimistic null object that returns True instead.
 695 if not conf:
 696     def NullCheck(*args, **kwargs):
 697         return True
 698
 699     class NullConf:
 700         def __init__(self, env):
 701             self.env = env
 702         def Finish(self):
 703             return self.env
 704         def __getattr__(self, mname):
 705             return NullCheck
 706
 707     conf = NullConf(main)
 708
 709 # Cache build files in the supplied directory.
 710 if main['M5_BUILD_CACHE']:
 711     print 'Using build cache located at', main['M5_BUILD_CACHE']
 712     CacheDir(main['M5_BUILD_CACHE'])
 713
 714 main['USE_PYTHON'] = not GetOption('without_python')
 715 if main['USE_PYTHON']:
 716     # Find Python include and library directories for embedding the
 717     # interpreter. We rely on python-config to resolve the appropriate
 718     # includes and linker flags. ParseConfig does not seem to understand
 719     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 720     # we add them explicitly below. If you want to link in an alternate
 721     # version of python, see above for instructions on how to invoke
 722     # scons with the appropriate PATH set.
 723     #
 724     # First we check if python2-config exists, else we use python-config
 725     python_config = readCommand(['which', 'python2-config'],
 726                                 exception='').strip()
 727     if not os.path.exists(python_config):
 728         python_config = readCommand(['which', 'python-config'],
 729                                     exception='').strip()
 730     py_includes = readCommand([python_config, '--includes'],
 731                               exception='').split()
 732     # Strip the -I from the include folders before adding them to the
 733     # CPPPATH
 734     main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
 735
 736     # Read the linker flags and split them into libraries and other link
 737     # flags. The libraries are added later through the call the CheckLib.
 738     py_ld_flags = readCommand([python_config, '--ldflags'],
 739         exception='').split()
 740     py_libs = []
 741     for lib in py_ld_flags:
 742          if not lib.startswith('-l'):
 743              main.Append(LINKFLAGS=[lib])
 744          else:
 745              lib = lib[2:]
 746              if lib not in py_libs:
 747                  py_libs.append(lib)
 748
 749     # verify that this stuff works
 750     if not conf.CheckHeader('Python.h', '<>'):
 751         print "Error: can't find Python.h header in", py_includes
 752         print "Install Python headers (package python-dev on Ubuntu and RedHat)"
 753         Exit(1)
 754
 755     for lib in py_libs:
 756         if not conf.CheckLib(lib):
 757             print "Error: can't find library %s required by python" % lib
 758             Exit(1)
 759
 760 # On Solaris you need to use libsocket for socket ops
 761 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 762    if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 763        print "Can't find library with socket calls (e.g. accept())"
 764        Exit(1)
 765
 766 # Check for zlib.  If the check passes, libz will be automatically
 767 # added to the LIBS environment variable.
 768 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 769     print 'Error: did not find needed zlib compression library '\
 770           'and/or zlib.h header file.'
 771     print '       Please install zlib and try again.'
 772     Exit(1)
 773
 774 # If we have the protobuf compiler, also make sure we have the
 775 # development libraries. If the check passes, libprotobuf will be
 776 # automatically added to the LIBS environment variable. After
 777 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 778 # got both protoc and libprotobuf available.
 779 main['HAVE_PROTOBUF'] = main['PROTOC'] and \
 780     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 781                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 782
 783 # If we have the compiler but not the library, print another warning.
 784 if main['PROTOC'] and not main['HAVE_PROTOBUF']:
 785     print termcap.Yellow + termcap.Bold + \
 786         'Warning: did not find protocol buffer library and/or headers.\n' + \
 787     '       Please install libprotobuf-dev for tracing support.' + \
 788     termcap.Normal
 789
 790 # Check for librt.
 791 have_posix_clock = \
 792     conf.CheckLibWithHeader(None, 'time.h', 'C',
 793                             'clock_nanosleep(0,0,NULL,NULL);') or \
 794     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 795                             'clock_nanosleep(0,0,NULL,NULL);')
 796
 797 have_posix_timers = \
 798     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 799                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 800
 801 if not GetOption('without_tcmalloc'):
 802     if conf.CheckLib('tcmalloc'):
 803         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 804     elif conf.CheckLib('tcmalloc_minimal'):
 805         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 806     else:
 807         print termcap.Yellow + termcap.Bold + \
 808               "You can get a 12% performance improvement by "\
 809               "installing tcmalloc (libgoogle-perftools-dev package "\
 810               "on Ubuntu or RedHat)." + termcap.Normal
 811
 812
 813 # Detect back trace implementations. The last implementation in the
 814 # list will be used by default.
 815 backtrace_impls = [ "none" ]
 816
 817 backtrace_checker = 'char temp;' + \
 818     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 819 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 820     backtrace_impls.append("glibc")
 821 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 822                              backtrace_checker):
 823     # NetBSD and FreeBSD need libexecinfo.
 824     backtrace_impls.append("glibc")
 825     main.Append(LIBS=['execinfo'])
 826
 827 if backtrace_impls[-1] == "none":
 828     default_backtrace_impl = "none"
 829     print termcap.Yellow + termcap.Bold + \
 830         "No suitable back trace implementation found." + \
 831         termcap.Normal
 832
 833 if not have_posix_clock:
 834     print "Can't find library for POSIX clocks."
 835
 836 # Check for <fenv.h> (C99 FP environment control)
 837 have_fenv = conf.CheckHeader('fenv.h', '<>')
 838 if not have_fenv:
 839     print "Warning: Header file <fenv.h> not found."
 840     print "         This host has no IEEE FP rounding mode control."
 841
 842 # Check for <png.h> (libpng library needed if wanting to dump
 843 # frame buffer image in png format)
 844 have_png = conf.CheckHeader('png.h', '<>')
 845 if not have_png:
 846     print "Warning: Header file <png.h> not found."
 847     print "         This host has no libpng library."
 848     print "         Disabling support for PNG framebuffers."
 849
 850 # Check if we should enable KVM-based hardware virtualization. The API
 851 # we rely on exists since version 2.6.36 of the kernel, but somehow
 852 # the KVM_API_VERSION does not reflect the change. We test for one of
 853 # the types as a fall back.
 854 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 855 if not have_kvm:
 856     print "Info: Compatible header file <linux/kvm.h> not found, " \
 857         "disabling KVM support."
 858
 859 # Check if the TUN/TAP driver is available.
 860 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 861 if not have_tuntap:
 862     print "Info: Compatible header file <linux/if_tun.h> not found."
 863
 864 # x86 needs support for xsave. We test for the structure here since we
 865 # won't be able to run new tests by the time we know which ISA we're
 866 # targeting.
 867 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 868                                     '#include <linux/kvm.h>') != 0
 869
 870 # Check if the requested target ISA is compatible with the host
 871 def is_isa_kvm_compatible(isa):
 872     try:
 873         import platform
 874         host_isa = platform.machine()
 875     except:
 876         print "Warning: Failed to determine host ISA."
 877         return False
 878
 879     if not have_posix_timers:
 880         print "Warning: Can not enable KVM, host seems to lack support " \
 881             "for POSIX timers"
 882         return False
 883
 884     if isa == "arm":
 885         return host_isa in ( "armv7l", "aarch64" )
 886     elif isa == "x86":
 887         if host_isa != "x86_64":
 888             return False
 889
 890         if not have_kvm_xsave:
 891             print "KVM on x86 requires xsave support in kernel headers."
 892             return False
 893
 894         return True
 895     else:
 896         return False
 897
 898
 899 # Check if the exclude_host attribute is available. We want this to
 900 # get accurate instruction counts in KVM.
 901 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 902     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 903
 904
 905 ######################################################################
 906 #
 907 # Finish the configuration
 908 #
 909 main = conf.Finish()
 910
 911 ######################################################################
 912 #
 913 # Collect all non-global variables
 914 #
 915
 916 # Define the universe of supported ISAs
 917 all_isa_list = [ ]
 918 all_gpu_isa_list = [ ]
 919 Export('all_isa_list')
 920 Export('all_gpu_isa_list')
 921
 922 class CpuModel(object):
 923     '''The CpuModel class encapsulates everything the ISA parser needs to
 924     know about a particular CPU model.'''
 925
 926     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 927     dict = {}
 928
 929     # Constructor.  Automatically adds models to CpuModel.dict.
 930     def __init__(self, name, default=False):
 931         self.name = name           # name of model
 932
 933         # This cpu is enabled by default
 934         self.default = default
 935
 936         # Add self to dict
 937         if name in CpuModel.dict:
 938             raise AttributeError, "CpuModel '%s' already registered" % name
 939         CpuModel.dict[name] = self
 940
 941 Export('CpuModel')
 942
 943 # Sticky variables get saved in the variables file so they persist from
 944 # one invocation to the next (unless overridden, in which case the new
 945 # value becomes sticky).
 946 sticky_vars = Variables(args=ARGUMENTS)
 947 Export('sticky_vars')
 948
 949 # Sticky variables that should be exported
 950 export_vars = []
 951 Export('export_vars')
 952
 953 # For Ruby
 954 all_protocols = []
 955 Export('all_protocols')
 956 protocol_dirs = []
 957 Export('protocol_dirs')
 958 slicc_includes = []
 959 Export('slicc_includes')
 960
 961 # Walk the tree and execute all SConsopts scripts that wil add to the
 962 # above variables
 963 if GetOption('verbose'):
 964     print "Reading SConsopts"
 965 for bdir in [ base_dir ] + extras_dir_list:
 966     if not isdir(bdir):
 967         print "Error: directory '%s' does not exist" % bdir
 968         Exit(1)
 969     for root, dirs, files in os.walk(bdir):
 970         if 'SConsopts' in files:
 971             if GetOption('verbose'):
 972                 print "Reading", joinpath(root, 'SConsopts')
 973             SConscript(joinpath(root, 'SConsopts'))
 974
 975 all_isa_list.sort()
 976 all_gpu_isa_list.sort()
 977
 978 sticky_vars.AddVariables(
 979     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 980     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 981     ListVariable('CPU_MODELS', 'CPU models',
 982                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
 983                  sorted(CpuModel.dict.keys())),
 984     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 985                  False),
 986     BoolVariable('SS_COMPATIBLE_FP',
 987                  'Make floating-point results compatible with SimpleScalar',
 988                  False),
 989     BoolVariable('USE_SSE2',
 990                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 991                  False),
 992     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 993     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 994     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 995     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
 996                  False),
 997     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
 998                  have_kvm),
 999     BoolVariable('USE_TUNTAP',
1000                  'Enable using a tap device to bridge to the host network',
1001                  have_tuntap),
1002     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1003     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1004                   all_protocols),
1005     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1006                  backtrace_impls[-1], backtrace_impls)
1007     )
1008
1009 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1010 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1011                 'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP',
1012                 'PROTOCOL', 'HAVE_PROTOBUF', 'HAVE_PERF_ATTR_EXCLUDE_HOST',
1013                 'USE_PNG']
1014
1015 ###################################################
1016 #
1017 # Define a SCons builder for configuration flag headers.
1018 #
1019 ###################################################
1020
1021 # This function generates a config header file that #defines the
1022 # variable symbol to the current variable setting (0 or 1).  The source
1023 # operands are the name of the variable and a Value node containing the
1024 # value of the variable.
1025 def build_config_file(target, source, env):
1026     (variable, value) = [s.get_contents() for s in source]
1027     f = file(str(target[0]), 'w')
1028     print >> f, '#define', variable, value
1029     f.close()
1030     return None
1031
1032 # Combine the two functions into a scons Action object.
1033 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1034
1035 # The emitter munges the source & target node lists to reflect what
1036 # we're really doing.
1037 def config_emitter(target, source, env):
1038     # extract variable name from Builder arg
1039     variable = str(target[0])
1040     # True target is config header file
1041     target = joinpath('config', variable.lower() + '.hh')
1042     val = env[variable]
1043     if isinstance(val, bool):
1044         # Force value to 0/1
1045         val = int(val)
1046     elif isinstance(val, str):
1047         val = '"' + val + '"'
1048
1049     # Sources are variable name & value (packaged in SCons Value nodes)
1050     return ([target], [Value(variable), Value(val)])
1051
1052 config_builder = Builder(emitter = config_emitter, action = config_action)
1053
1054 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1055
1056 ###################################################
1057 #
1058 # Builders for static and shared partially linked object files.
1059 #
1060 ###################################################
1061
1062 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1063                                  src_suffix='$OBJSUFFIX',
1064                                  src_builder=['StaticObject', 'Object'],
1065                                  LINKFLAGS='$PLINKFLAGS',
1066                                  LIBS='')
1067
1068 def partial_shared_emitter(target, source, env):
1069     for tgt in target:
1070         tgt.attributes.shared = 1
1071     return (target, source)
1072 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1073                                  emitter=partial_shared_emitter,
1074                                  src_suffix='$SHOBJSUFFIX',
1075                                  src_builder='SharedObject',
1076                                  SHLINKFLAGS='$PSHLINKFLAGS',
1077                                  LIBS='')
1078
1079 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1080                          'PartialStatic' : partial_static_builder })
1081
1082 # builds in ext are shared across all configs in the build root.
1083 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1084 ext_build_dirs = []
1085 for root, dirs, files in os.walk(ext_dir):
1086     if 'SConscript' in files:
1087         build_dir = os.path.relpath(root, ext_dir)
1088         ext_build_dirs.append(build_dir)
1089         main.SConscript(joinpath(root, 'SConscript'),
1090                         variant_dir=joinpath(build_root, build_dir))
1091
1092 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1093
1094 ###################################################
1095 #
1096 # This builder and wrapper method are used to set up a directory with
1097 # switching headers. Those are headers which are in a generic location and
1098 # that include more specific headers from a directory chosen at build time
1099 # based on the current build settings.
1100 #
1101 ###################################################
1102
1103 def build_switching_header(target, source, env):
1104     path = str(target[0])
1105     subdir = str(source[0])
1106     dp, fp = os.path.split(path)
1107     dp = os.path.relpath(os.path.realpath(dp),
1108                          os.path.realpath(env['BUILDDIR']))
1109     with open(path, 'w') as hdr:
1110         print >>hdr, '#include "%s/%s/%s"' % (dp, subdir, fp)
1111
1112 switching_header_action = MakeAction(build_switching_header,
1113                                      Transform('GENERATE'))
1114
1115 switching_header_builder = Builder(action=switching_header_action,
1116                                    source_factory=Value,
1117                                    single_source=True)
1118
1119 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1120
1121 def switching_headers(self, headers, source):
1122     for header in headers:
1123         self.SwitchingHeader(header, source)
1124
1125 main.AddMethod(switching_headers, 'SwitchingHeaders')
1126
1127 ###################################################
1128 #
1129 # Define build environments for selected configurations.
1130 #
1131 ###################################################
1132
1133 for variant_path in variant_paths:
1134     if not GetOption('silent'):
1135         print "Building in", variant_path
1136
1137     # Make a copy of the build-root environment to use for this config.
1138     env = main.Clone()
1139     env['BUILDDIR'] = variant_path
1140
1141     # variant_dir is the tail component of build path, and is used to
1142     # determine the build parameters (e.g., 'ALPHA_SE')
1143     (build_root, variant_dir) = splitpath(variant_path)
1144
1145     # Set env variables according to the build directory config.
1146     sticky_vars.files = []
1147     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1148     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1149     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1150     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1151     if isfile(current_vars_file):
1152         sticky_vars.files.append(current_vars_file)
1153         if not GetOption('silent'):
1154             print "Using saved variables file %s" % current_vars_file
1155     elif variant_dir in ext_build_dirs:
1156         # Things in ext are built without a variant directory.
1157         continue
1158     else:
1159         # Build dir-specific variables file doesn't exist.
1160
1161         # Make sure the directory is there so we can create it later
1162         opt_dir = dirname(current_vars_file)
1163         if not isdir(opt_dir):
1164             mkdir(opt_dir)
1165
1166         # Get default build variables from source tree.  Variables are
1167         # normally determined by name of $VARIANT_DIR, but can be
1168         # overridden by '--default=' arg on command line.
1169         default = GetOption('default')
1170         opts_dir = joinpath(main.root.abspath, 'build_opts')
1171         if default:
1172             default_vars_files = [joinpath(build_root, 'variables', default),
1173                                   joinpath(opts_dir, default)]
1174         else:
1175             default_vars_files = [joinpath(opts_dir, variant_dir)]
1176         existing_files = filter(isfile, default_vars_files)
1177         if existing_files:
1178             default_vars_file = existing_files[0]
1179             sticky_vars.files.append(default_vars_file)
1180             print "Variables file %s not found,\n  using defaults in %s" \
1181                   % (current_vars_file, default_vars_file)
1182         else:
1183             print "Error: cannot find variables file %s or " \
1184                   "default file(s) %s" \
1185                   % (current_vars_file, ' or '.join(default_vars_files))
1186             Exit(1)
1187
1188     # Apply current variable settings to env
1189     sticky_vars.Update(env)
1190
1191     help_texts["local_vars"] += \
1192         "Build variables for %s:\n" % variant_dir \
1193                  + sticky_vars.GenerateHelpText(env)
1194
1195     # Process variable settings.
1196
1197     if not have_fenv and env['USE_FENV']:
1198         print "Warning: <fenv.h> not available; " \
1199               "forcing USE_FENV to False in", variant_dir + "."
1200         env['USE_FENV'] = False
1201
1202     if not env['USE_FENV']:
1203         print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1204         print "         FP results may deviate slightly from other platforms."
1205
1206     if not have_png and env['USE_PNG']:
1207         print "Warning: <png.h> not available; " \
1208               "forcing USE_PNG to False in", variant_dir + "."
1209         env['USE_PNG'] = False
1210
1211     if env['USE_PNG']:
1212         env.Append(LIBS=['png'])
1213
1214     if env['EFENCE']:
1215         env.Append(LIBS=['efence'])
1216
1217     if env['USE_KVM']:
1218         if not have_kvm:
1219             print "Warning: Can not enable KVM, host seems to lack KVM support"
1220             env['USE_KVM'] = False
1221         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1222             print "Info: KVM support disabled due to unsupported host and " \
1223                 "target ISA combination"
1224             env['USE_KVM'] = False
1225
1226     if env['USE_TUNTAP']:
1227         if not have_tuntap:
1228             print "Warning: Can't connect EtherTap with a tap device."
1229             env['USE_TUNTAP'] = False
1230
1231     if env['BUILD_GPU']:
1232         env.Append(CPPDEFINES=['BUILD_GPU'])
1233
1234     # Warn about missing optional functionality
1235     if env['USE_KVM']:
1236         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1237             print "Warning: perf_event headers lack support for the " \
1238                 "exclude_host attribute. KVM instruction counts will " \
1239                 "be inaccurate."
1240
1241     # Save sticky variable settings back to current variables file
1242     sticky_vars.Save(current_vars_file, env)
1243
1244     if env['USE_SSE2']:
1245         env.Append(CCFLAGS=['-msse2'])
1246
1247     # The src/SConscript file sets up the build rules in 'env' according
1248     # to the configured variables.  It returns a list of environments,
1249     # one for each variant build (debug, opt, etc.)
1250     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1251
1252 # base help text
1253 Help('''
1254 Usage: scons [scons options] [build variables] [target(s)]
1255
1256 Extra scons options:
1257 %(options)s
1258
1259 Global build variables:
1260 %(global_vars)s
1261
1262 %(local_vars)s
1263 ''' % help_texts)