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
  96 # SCons includes
  97 import SCons
  98 import SCons.Node
  99
 100 from m5.util import compareVersions, readCommand
 101
 102 help_texts = {
 103     "options" : "",
 104     "global_vars" : "",
 105     "local_vars" : ""
 106 }
 107
 108 Export("help_texts")
 109
 110
 111 # There's a bug in scons in that (1) by default, the help texts from
 112 # AddOption() are supposed to be displayed when you type 'scons -h'
 113 # and (2) you can override the help displayed by 'scons -h' using the
 114 # Help() function, but these two features are incompatible: once
 115 # you've overridden the help text using Help(), there's no way to get
 116 # at the help texts from AddOptions.  See:
 117 #     http://scons.tigris.org/issues/show_bug.cgi?id=2356
 118 #     http://scons.tigris.org/issues/show_bug.cgi?id=2611
 119 # This hack lets us extract the help text from AddOptions and
 120 # re-inject it via Help().  Ideally someday this bug will be fixed and
 121 # we can just use AddOption directly.
 122 def AddLocalOption(*args, **kwargs):
 123     col_width = 30
 124
 125     help = "  " + ", ".join(args)
 126     if "help" in kwargs:
 127         length = len(help)
 128         if length >= col_width:
 129             help += "\n" + " " * col_width
 130         else:
 131             help += " " * (col_width - length)
 132         help += kwargs["help"]
 133     help_texts["options"] += help + "\n"
 134
 135     AddOption(*args, **kwargs)
 136
 137 AddLocalOption('--colors', dest='use_colors', action='store_true',
 138                help="Add color to abbreviated scons output")
 139 AddLocalOption('--no-colors', dest='use_colors', action='store_false',
 140                help="Don't add color to abbreviated scons output")
 141 AddLocalOption('--with-cxx-config', dest='with_cxx_config',
 142                action='store_true',
 143                help="Build with support for C++-based configuration")
 144 AddLocalOption('--default', dest='default', type='string', action='store',
 145                help='Override which build_opts file to use for defaults')
 146 AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
 147                help='Disable style checking hooks')
 148 AddLocalOption('--no-lto', dest='no_lto', action='store_true',
 149                help='Disable Link-Time Optimization for fast')
 150 AddLocalOption('--force-lto', dest='force_lto', action='store_true',
 151                help='Use Link-Time Optimization instead of partial linking' +
 152                     ' when the compiler doesn\'t support using them together.')
 153 AddLocalOption('--update-ref', dest='update_ref', action='store_true',
 154                help='Update test reference outputs')
 155 AddLocalOption('--verbose', dest='verbose', action='store_true',
 156                help='Print full tool command lines')
 157 AddLocalOption('--without-python', dest='without_python',
 158                action='store_true',
 159                help='Build without Python configuration support')
 160 AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
 161                action='store_true',
 162                help='Disable linking against tcmalloc')
 163 AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
 164                help='Build with Undefined Behavior Sanitizer if available')
 165 AddLocalOption('--with-asan', dest='with_asan', action='store_true',
 166                help='Build with Address Sanitizer if available')
 167
 168 if GetOption('no_lto') and GetOption('force_lto'):
 169     print('--no-lto and --force-lto are mutually exclusive')
 170     Exit(1)
 171
 172 ########################################################################
 173 #
 174 # Set up the main build environment.
 175 #
 176 ########################################################################
 177
 178 main = Environment()
 179
 180 from gem5_scons import Transform
 181 from gem5_scons.util import get_termcap
 182 termcap = get_termcap()
 183
 184 main_dict_keys = main.Dictionary().keys()
 185
 186 # Check that we have a C/C++ compiler
 187 if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
 188     print("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
 189     Exit(1)
 190
 191 ###################################################
 192 #
 193 # Figure out which configurations to set up based on the path(s) of
 194 # the target(s).
 195 #
 196 ###################################################
 197
 198 # Find default configuration & binary.
 199 Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
 200
 201 # helper function: find last occurrence of element in list
 202 def rfind(l, elt, offs = -1):
 203     for i in range(len(l)+offs, 0, -1):
 204         if l[i] == elt:
 205             return i
 206     raise ValueError, "element not found"
 207
 208 # Take a list of paths (or SCons Nodes) and return a list with all
 209 # paths made absolute and ~-expanded.  Paths will be interpreted
 210 # relative to the launch directory unless a different root is provided
 211 def makePathListAbsolute(path_list, root=GetLaunchDir()):
 212     return [abspath(joinpath(root, expanduser(str(p))))
 213             for p in path_list]
 214
 215 # Each target must have 'build' in the interior of the path; the
 216 # directory below this will determine the build parameters.  For
 217 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
 218 # recognize that ALPHA_SE specifies the configuration because it
 219 # follow 'build' in the build path.
 220
 221 # The funky assignment to "[:]" is needed to replace the list contents
 222 # in place rather than reassign the symbol to a new list, which
 223 # doesn't work (obviously!).
 224 BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
 225
 226 # Generate a list of the unique build roots and configs that the
 227 # collected targets reference.
 228 variant_paths = []
 229 build_root = None
 230 for t in BUILD_TARGETS:
 231     path_dirs = t.split('/')
 232     try:
 233         build_top = rfind(path_dirs, 'build', -2)
 234     except:
 235         print("Error: no non-leaf 'build' dir found on target path", t)
 236         Exit(1)
 237     this_build_root = joinpath('/',*path_dirs[:build_top+1])
 238     if not build_root:
 239         build_root = this_build_root
 240     else:
 241         if this_build_root != build_root:
 242             print("Error: build targets not under same build root\n"
 243                   "  %s\n  %s" % (build_root, this_build_root))
 244             Exit(1)
 245     variant_path = joinpath('/',*path_dirs[:build_top+2])
 246     if variant_path not in variant_paths:
 247         variant_paths.append(variant_path)
 248
 249 # Make sure build_root exists (might not if this is the first build there)
 250 if not isdir(build_root):
 251     mkdir(build_root)
 252 main['BUILDROOT'] = build_root
 253
 254 Export('main')
 255
 256 main.SConsignFile(joinpath(build_root, "sconsign"))
 257
 258 # Default duplicate option is to use hard links, but this messes up
 259 # when you use emacs to edit a file in the target dir, as emacs moves
 260 # file to file~ then copies to file, breaking the link.  Symbolic
 261 # (soft) links work better.
 262 main.SetOption('duplicate', 'soft-copy')
 263
 264 #
 265 # Set up global sticky variables... these are common to an entire build
 266 # tree (not specific to a particular build like ALPHA_SE)
 267 #
 268
 269 global_vars_file = joinpath(build_root, 'variables.global')
 270
 271 global_vars = Variables(global_vars_file, args=ARGUMENTS)
 272
 273 global_vars.AddVariables(
 274     ('CC', 'C compiler', environ.get('CC', main['CC'])),
 275     ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
 276     ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
 277     ('BATCH', 'Use batch pool for build and tests', False),
 278     ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
 279     ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
 280     ('EXTRAS', 'Add extra directories to the compilation', '')
 281     )
 282
 283 # Update main environment with values from ARGUMENTS & global_vars_file
 284 global_vars.Update(main)
 285 help_texts["global_vars"] += global_vars.GenerateHelpText(main)
 286
 287 # Save sticky variable settings back to current variables file
 288 global_vars.Save(global_vars_file, main)
 289
 290 # Parse EXTRAS variable to build list of all directories where we're
 291 # look for sources etc.  This list is exported as extras_dir_list.
 292 base_dir = main.srcdir.abspath
 293 if main['EXTRAS']:
 294     extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
 295 else:
 296     extras_dir_list = []
 297
 298 Export('base_dir')
 299 Export('extras_dir_list')
 300
 301 # the ext directory should be on the #includes path
 302 main.Append(CPPPATH=[Dir('ext')])
 303
 304 # Add shared top-level headers
 305 main.Prepend(CPPPATH=Dir('include'))
 306
 307 if GetOption('verbose'):
 308     def MakeAction(action, string, *args, **kwargs):
 309         return Action(action, *args, **kwargs)
 310 else:
 311     MakeAction = Action
 312     main['CCCOMSTR']        = Transform("CC")
 313     main['CXXCOMSTR']       = Transform("CXX")
 314     main['ASCOMSTR']        = Transform("AS")
 315     main['ARCOMSTR']        = Transform("AR", 0)
 316     main['LINKCOMSTR']      = Transform("LINK", 0)
 317     main['SHLINKCOMSTR']    = Transform("SHLINK", 0)
 318     main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
 319     main['M4COMSTR']        = Transform("M4")
 320     main['SHCCCOMSTR']      = Transform("SHCC")
 321     main['SHCXXCOMSTR']     = Transform("SHCXX")
 322 Export('MakeAction')
 323
 324 # Initialize the Link-Time Optimization (LTO) flags
 325 main['LTO_CCFLAGS'] = []
 326 main['LTO_LDFLAGS'] = []
 327
 328 # According to the readme, tcmalloc works best if the compiler doesn't
 329 # assume that we're using the builtin malloc and friends. These flags
 330 # are compiler-specific, so we need to set them after we detect which
 331 # compiler we're using.
 332 main['TCMALLOC_CCFLAGS'] = []
 333
 334 CXX_version = readCommand([main['CXX'],'--version'], exception=False)
 335 CXX_V = readCommand([main['CXX'],'-V'], exception=False)
 336
 337 main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
 338 main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
 339 if main['GCC'] + main['CLANG'] > 1:
 340     print('Error: How can we have two at the same time?')
 341     Exit(1)
 342
 343 # Set up default C++ compiler flags
 344 if main['GCC'] or main['CLANG']:
 345     # As gcc and clang share many flags, do the common parts here
 346     main.Append(CCFLAGS=['-pipe'])
 347     main.Append(CCFLAGS=['-fno-strict-aliasing'])
 348     # Enable -Wall and -Wextra and then disable the few warnings that
 349     # we consistently violate
 350     main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
 351                          '-Wno-sign-compare', '-Wno-unused-parameter'])
 352     # We always compile using C++11
 353     main.Append(CXXFLAGS=['-std=c++11'])
 354     if sys.platform.startswith('freebsd'):
 355         main.Append(CCFLAGS=['-I/usr/local/include'])
 356         main.Append(CXXFLAGS=['-I/usr/local/include'])
 357
 358     main['FILTER_PSHLINKFLAGS'] = lambda x: str(x).replace(' -shared', '')
 359     main['PSHLINKFLAGS'] = main.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
 360     main['PLINKFLAGS'] = main.subst('${LINKFLAGS}')
 361     shared_partial_flags = ['-r', '-nostdlib']
 362     main.Append(PSHLINKFLAGS=shared_partial_flags)
 363     main.Append(PLINKFLAGS=shared_partial_flags)
 364
 365     # Treat warnings as errors but white list some warnings that we
 366     # want to allow (e.g., deprecation warnings).
 367     main.Append(CCFLAGS=['-Werror',
 368                          '-Wno-error=deprecated-declarations',
 369                          '-Wno-error=deprecated',
 370                         ])
 371 else:
 372     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 373     print("Don't know what compiler options to use for your compiler.")
 374     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 375     print(termcap.Yellow + '       version:' + termcap.Normal, end = ' ')
 376     if not CXX_version:
 377         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 378               termcap.Normal)
 379     else:
 380         print(CXX_version.replace('\n', '<nl>'))
 381     print("       If you're trying to use a compiler other than GCC")
 382     print("       or clang, there appears to be something wrong with your")
 383     print("       environment.")
 384     print("       ")
 385     print("       If you are trying to use a compiler other than those listed")
 386     print("       above you will need to ease fix SConstruct and ")
 387     print("       src/SConscript to support that compiler.")
 388     Exit(1)
 389
 390 if main['GCC']:
 391     # Check for a supported version of gcc. >= 4.8 is chosen for its
 392     # level of c++11 support. See
 393     # http://gcc.gnu.org/projects/cxx0x.html for details.
 394     gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
 395     if compareVersions(gcc_version, "4.8") < 0:
 396         print('Error: gcc version 4.8 or newer required.')
 397         print('       Installed version: ', gcc_version)
 398         Exit(1)
 399
 400     main['GCC_VERSION'] = gcc_version
 401
 402     if compareVersions(gcc_version, '4.9') >= 0:
 403         # Incremental linking with LTO is currently broken in gcc versions
 404         # 4.9 and above. A version where everything works completely hasn't
 405         # yet been identified.
 406         #
 407         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
 408         main['BROKEN_INCREMENTAL_LTO'] = True
 409     if compareVersions(gcc_version, '6.0') >= 0:
 410         # gcc versions 6.0 and greater accept an -flinker-output flag which
 411         # selects what type of output the linker should generate. This is
 412         # necessary for incremental lto to work, but is also broken in
 413         # current versions of gcc. It may not be necessary in future
 414         # versions. We add it here since it might be, and as a reminder that
 415         # it exists. It's excluded if lto is being forced.
 416         #
 417         # https://gcc.gnu.org/gcc-6/changes.html
 418         # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
 419         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
 420         if not GetOption('force_lto'):
 421             main.Append(PSHLINKFLAGS='-flinker-output=rel')
 422             main.Append(PLINKFLAGS='-flinker-output=rel')
 423
 424     # gcc from version 4.8 and above generates "rep; ret" instructions
 425     # to avoid performance penalties on certain AMD chips. Older
 426     # assemblers detect this as an error, "Error: expecting string
 427     # instruction after `rep'"
 428     as_version_raw = readCommand([main['AS'], '-v', '/dev/null',
 429                                   '-o', '/dev/null'],
 430                                  exception=False).split()
 431
 432     # version strings may contain extra distro-specific
 433     # qualifiers, so play it safe and keep only what comes before
 434     # the first hyphen
 435     as_version = as_version_raw[-1].split('-')[0] if as_version_raw else None
 436
 437     if not as_version or compareVersions(as_version, "2.23") < 0:
 438         print(termcap.Yellow + termcap.Bold +
 439             'Warning: This combination of gcc and binutils have' +
 440             ' known incompatibilities.\n' +
 441             '         If you encounter build problems, please update ' +
 442             'binutils to 2.23.' +
 443             termcap.Normal)
 444
 445     # Make sure we warn if the user has requested to compile with the
 446     # Undefined Benahvior Sanitizer and this version of gcc does not
 447     # support it.
 448     if GetOption('with_ubsan') and \
 449             compareVersions(gcc_version, '4.9') < 0:
 450         print(termcap.Yellow + termcap.Bold +
 451             'Warning: UBSan is only supported using gcc 4.9 and later.' +
 452             termcap.Normal)
 453
 454     disable_lto = GetOption('no_lto')
 455     if not disable_lto and main.get('BROKEN_INCREMENTAL_LTO', False) and \
 456             not GetOption('force_lto'):
 457         print(termcap.Yellow + termcap.Bold +
 458             'Warning: Your compiler doesn\'t support incremental linking' +
 459             ' and lto at the same time, so lto is being disabled. To force' +
 460             ' lto on anyway, use the --force-lto option. That will disable' +
 461             ' partial linking.' +
 462             termcap.Normal)
 463         disable_lto = True
 464
 465     # Add the appropriate Link-Time Optimization (LTO) flags
 466     # unless LTO is explicitly turned off. Note that these flags
 467     # are only used by the fast target.
 468     if not disable_lto:
 469         # Pass the LTO flag when compiling to produce GIMPLE
 470         # output, we merely create the flags here and only append
 471         # them later
 472         main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 473
 474         # Use the same amount of jobs for LTO as we are running
 475         # scons with
 476         main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
 477
 478     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
 479                                   '-fno-builtin-realloc', '-fno-builtin-free'])
 480
 481     # The address sanitizer is available for gcc >= 4.8
 482     if GetOption('with_asan'):
 483         if GetOption('with_ubsan') and \
 484                 compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 485             main.Append(CCFLAGS=['-fsanitize=address,undefined',
 486                                  '-fno-omit-frame-pointer'],
 487                        LINKFLAGS='-fsanitize=address,undefined')
 488         else:
 489             main.Append(CCFLAGS=['-fsanitize=address',
 490                                  '-fno-omit-frame-pointer'],
 491                        LINKFLAGS='-fsanitize=address')
 492     # Only gcc >= 4.9 supports UBSan, so check both the version
 493     # and the command-line option before adding the compiler and
 494     # linker flags.
 495     elif GetOption('with_ubsan') and \
 496             compareVersions(main['GCC_VERSION'], '4.9') >= 0:
 497         main.Append(CCFLAGS='-fsanitize=undefined')
 498         main.Append(LINKFLAGS='-fsanitize=undefined')
 499
 500 elif main['CLANG']:
 501     # Check for a supported version of clang, >= 3.1 is needed to
 502     # support similar features as gcc 4.8. See
 503     # http://clang.llvm.org/cxx_status.html for details
 504     clang_version_re = re.compile(".* version (\d+\.\d+)")
 505     clang_version_match = clang_version_re.search(CXX_version)
 506     if (clang_version_match):
 507         clang_version = clang_version_match.groups()[0]
 508         if compareVersions(clang_version, "3.1") < 0:
 509             print('Error: clang version 3.1 or newer required.')
 510             print('       Installed version:', clang_version)
 511             Exit(1)
 512     else:
 513         print('Error: Unable to determine clang version.')
 514         Exit(1)
 515
 516     # clang has a few additional warnings that we disable, extraneous
 517     # parantheses are allowed due to Ruby's printing of the AST,
 518     # finally self assignments are allowed as the generated CPU code
 519     # is relying on this
 520     main.Append(CCFLAGS=['-Wno-parentheses',
 521                          '-Wno-self-assign',
 522                          # Some versions of libstdc++ (4.8?) seem to
 523                          # use struct hash and class hash
 524                          # interchangeably.
 525                          '-Wno-mismatched-tags',
 526                          ])
 527
 528     main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
 529
 530     # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
 531     # opposed to libstdc++, as the later is dated.
 532     if sys.platform == "darwin":
 533         main.Append(CXXFLAGS=['-stdlib=libc++'])
 534         main.Append(LIBS=['c++'])
 535
 536     # On FreeBSD we need libthr.
 537     if sys.platform.startswith('freebsd'):
 538         main.Append(LIBS=['thr'])
 539
 540     # We require clang >= 3.1, so there is no need to check any
 541     # versions here.
 542     if GetOption('with_ubsan'):
 543         if GetOption('with_asan'):
 544             env.Append(CCFLAGS=['-fsanitize=address,undefined',
 545                                 '-fno-omit-frame-pointer'],
 546                        LINKFLAGS='-fsanitize=address,undefined')
 547         else:
 548             env.Append(CCFLAGS='-fsanitize=undefined',
 549                        LINKFLAGS='-fsanitize=undefined')
 550
 551     elif GetOption('with_asan'):
 552         env.Append(CCFLAGS=['-fsanitize=address',
 553                             '-fno-omit-frame-pointer'],
 554                    LINKFLAGS='-fsanitize=address')
 555
 556 else:
 557     print(termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal, end=' ')
 558     print("Don't know what compiler options to use for your compiler.")
 559     print(termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX'])
 560     print(termcap.Yellow + '       version:' + termcap.Normal, end=' ')
 561     if not CXX_version:
 562         print(termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +
 563               termcap.Normal)
 564     else:
 565         print(CXX_version.replace('\n', '<nl>'))
 566     print("       If you're trying to use a compiler other than GCC")
 567     print("       or clang, there appears to be something wrong with your")
 568     print("       environment.")
 569     print("       ")
 570     print("       If you are trying to use a compiler other than those listed")
 571     print("       above you will need to ease fix SConstruct and ")
 572     print("       src/SConscript to support that compiler.")
 573     Exit(1)
 574
 575 # Set up common yacc/bison flags (needed for Ruby)
 576 main['YACCFLAGS'] = '-d'
 577 main['YACCHXXFILESUFFIX'] = '.hh'
 578
 579 # Do this after we save setting back, or else we'll tack on an
 580 # extra 'qdo' every time we run scons.
 581 if main['BATCH']:
 582     main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
 583     main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
 584     main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
 585     main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
 586     main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
 587
 588 if sys.platform == 'cygwin':
 589     # cygwin has some header file issues...
 590     main.Append(CCFLAGS=["-Wno-uninitialized"])
 591
 592 # Check for the protobuf compiler
 593 protoc_version = readCommand([main['PROTOC'], '--version'],
 594                              exception='').split()
 595
 596 # First two words should be "libprotoc x.y.z"
 597 if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
 598     print(termcap.Yellow + termcap.Bold +
 599         'Warning: Protocol buffer compiler (protoc) not found.\n' +
 600         '         Please install protobuf-compiler for tracing support.' +
 601         termcap.Normal)
 602     main['PROTOC'] = False
 603 else:
 604     # Based on the availability of the compress stream wrappers,
 605     # require 2.1.0
 606     min_protoc_version = '2.1.0'
 607     if compareVersions(protoc_version[1], min_protoc_version) < 0:
 608         print(termcap.Yellow + termcap.Bold +
 609             'Warning: protoc version', min_protoc_version,
 610             'or newer required.\n' +
 611             '         Installed version:', protoc_version[1],
 612             termcap.Normal)
 613         main['PROTOC'] = False
 614     else:
 615         # Attempt to determine the appropriate include path and
 616         # library path using pkg-config, that means we also need to
 617         # check for pkg-config. Note that it is possible to use
 618         # protobuf without the involvement of pkg-config. Later on we
 619         # check go a library config check and at that point the test
 620         # will fail if libprotobuf cannot be found.
 621         if readCommand(['pkg-config', '--version'], exception=''):
 622             try:
 623                 # Attempt to establish what linking flags to add for protobuf
 624                 # using pkg-config
 625                 main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
 626             except:
 627                 print(termcap.Yellow + termcap.Bold +
 628                     'Warning: pkg-config could not get protobuf flags.' +
 629                     termcap.Normal)
 630
 631
 632 # Check for 'timeout' from GNU coreutils. If present, regressions will
 633 # be run with a time limit. We require version 8.13 since we rely on
 634 # support for the '--foreground' option.
 635 if sys.platform.startswith('freebsd'):
 636     timeout_lines = readCommand(['gtimeout', '--version'],
 637                                 exception='').splitlines()
 638 else:
 639     timeout_lines = readCommand(['timeout', '--version'],
 640                                 exception='').splitlines()
 641 # Get the first line and tokenize it
 642 timeout_version = timeout_lines[0].split() if timeout_lines else []
 643 main['TIMEOUT'] =  timeout_version and \
 644     compareVersions(timeout_version[-1], '8.13') >= 0
 645
 646 # Add a custom Check function to test for structure members.
 647 def CheckMember(context, include, decl, member, include_quotes="<>"):
 648     context.Message("Checking for member %s in %s..." %
 649                     (member, decl))
 650     text = """
 651 #include %(header)s
 652 int main(){
 653   %(decl)s test;
 654   (void)test.%(member)s;
 655   return 0;
 656 };
 657 """ % { "header" : include_quotes[0] + include + include_quotes[1],
 658         "decl" : decl,
 659         "member" : member,
 660         }
 661
 662     ret = context.TryCompile(text, extension=".cc")
 663     context.Result(ret)
 664     return ret
 665
 666 # Platform-specific configuration.  Note again that we assume that all
 667 # builds under a given build root run on the same host platform.
 668 conf = Configure(main,
 669                  conf_dir = joinpath(build_root, '.scons_config'),
 670                  log_file = joinpath(build_root, 'scons_config.log'),
 671                  custom_tests = {
 672         'CheckMember' : CheckMember,
 673         })
 674
 675 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
 676 try:
 677     import platform
 678     uname = platform.uname()
 679     if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
 680         if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
 681             main.Append(CCFLAGS=['-arch', 'x86_64'])
 682             main.Append(CFLAGS=['-arch', 'x86_64'])
 683             main.Append(LINKFLAGS=['-arch', 'x86_64'])
 684             main.Append(ASFLAGS=['-arch', 'x86_64'])
 685 except:
 686     pass
 687
 688 # Recent versions of scons substitute a "Null" object for Configure()
 689 # when configuration isn't necessary, e.g., if the "--help" option is
 690 # present.  Unfortuantely this Null object always returns false,
 691 # breaking all our configuration checks.  We replace it with our own
 692 # more optimistic null object that returns True instead.
 693 if not conf:
 694     def NullCheck(*args, **kwargs):
 695         return True
 696
 697     class NullConf:
 698         def __init__(self, env):
 699             self.env = env
 700         def Finish(self):
 701             return self.env
 702         def __getattr__(self, mname):
 703             return NullCheck
 704
 705     conf = NullConf(main)
 706
 707 # Cache build files in the supplied directory.
 708 if main['M5_BUILD_CACHE']:
 709     print('Using build cache located at', main['M5_BUILD_CACHE'])
 710     CacheDir(main['M5_BUILD_CACHE'])
 711
 712 main['USE_PYTHON'] = not GetOption('without_python')
 713 if main['USE_PYTHON']:
 714     # Find Python include and library directories for embedding the
 715     # interpreter. We rely on python-config to resolve the appropriate
 716     # includes and linker flags. ParseConfig does not seem to understand
 717     # the more exotic linker flags such as -Xlinker and -export-dynamic so
 718     # we add them explicitly below. If you want to link in an alternate
 719     # version of python, see above for instructions on how to invoke
 720     # scons with the appropriate PATH set.
 721     #
 722     # First we check if python2-config exists, else we use python-config
 723     python_config = readCommand(['which', 'python2-config'],
 724                                 exception='').strip()
 725     if not os.path.exists(python_config):
 726         python_config = readCommand(['which', 'python-config'],
 727                                     exception='').strip()
 728     py_includes = readCommand([python_config, '--includes'],
 729                               exception='').split()
 730     # Strip the -I from the include folders before adding them to the
 731     # CPPPATH
 732     main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
 733
 734     # Read the linker flags and split them into libraries and other link
 735     # flags. The libraries are added later through the call the CheckLib.
 736     py_ld_flags = readCommand([python_config, '--ldflags'],
 737         exception='').split()
 738     py_libs = []
 739     for lib in py_ld_flags:
 740          if not lib.startswith('-l'):
 741              main.Append(LINKFLAGS=[lib])
 742          else:
 743              lib = lib[2:]
 744              if lib not in py_libs:
 745                  py_libs.append(lib)
 746
 747     # verify that this stuff works
 748     if not conf.CheckHeader('Python.h', '<>'):
 749         print("Error: Check failed for Python.h header in", py_includes)
 750         print("Two possible reasons:")
 751         print("1. Python headers are not installed (You can install the "
 752               "package python-dev on Ubuntu and RedHat)")
 753         print("2. SCons is using a wrong C compiler. This can happen if "
 754               "CC has the wrong value.")
 755         print("CC = %s" % main['CC'])
 756         Exit(1)
 757
 758     for lib in py_libs:
 759         if not conf.CheckLib(lib):
 760             print("Error: can't find library %s required by python" % lib)
 761             Exit(1)
 762
 763 # On Solaris you need to use libsocket for socket ops
 764 if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 765    if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
 766        print("Can't find library with socket calls (e.g. accept())")
 767        Exit(1)
 768
 769 # Check for zlib.  If the check passes, libz will be automatically
 770 # added to the LIBS environment variable.
 771 if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
 772     print('Error: did not find needed zlib compression library '
 773           'and/or zlib.h header file.')
 774     print('       Please install zlib and try again.')
 775     Exit(1)
 776
 777 # If we have the protobuf compiler, also make sure we have the
 778 # development libraries. If the check passes, libprotobuf will be
 779 # automatically added to the LIBS environment variable. After
 780 # this, we can use the HAVE_PROTOBUF flag to determine if we have
 781 # got both protoc and libprotobuf available.
 782 main['HAVE_PROTOBUF'] = main['PROTOC'] and \
 783     conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
 784                             'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
 785
 786 # If we have the compiler but not the library, print another warning.
 787 if main['PROTOC'] and not main['HAVE_PROTOBUF']:
 788     print(termcap.Yellow + termcap.Bold +
 789         'Warning: did not find protocol buffer library and/or headers.\n' +
 790     '       Please install libprotobuf-dev for tracing support.' +
 791     termcap.Normal)
 792
 793 # Check for librt.
 794 have_posix_clock = \
 795     conf.CheckLibWithHeader(None, 'time.h', 'C',
 796                             'clock_nanosleep(0,0,NULL,NULL);') or \
 797     conf.CheckLibWithHeader('rt', 'time.h', 'C',
 798                             'clock_nanosleep(0,0,NULL,NULL);')
 799
 800 have_posix_timers = \
 801     conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
 802                             'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
 803
 804 if not GetOption('without_tcmalloc'):
 805     if conf.CheckLib('tcmalloc'):
 806         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 807     elif conf.CheckLib('tcmalloc_minimal'):
 808         main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
 809     else:
 810         print(termcap.Yellow + termcap.Bold +
 811               "You can get a 12% performance improvement by "
 812               "installing tcmalloc (libgoogle-perftools-dev package "
 813               "on Ubuntu or RedHat)." + termcap.Normal)
 814
 815
 816 # Detect back trace implementations. The last implementation in the
 817 # list will be used by default.
 818 backtrace_impls = [ "none" ]
 819
 820 backtrace_checker = 'char temp;' + \
 821     ' backtrace_symbols_fd((void*)&temp, 0, 0);'
 822 if conf.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker):
 823     backtrace_impls.append("glibc")
 824 elif conf.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
 825                              backtrace_checker):
 826     # NetBSD and FreeBSD need libexecinfo.
 827     backtrace_impls.append("glibc")
 828     main.Append(LIBS=['execinfo'])
 829
 830 if backtrace_impls[-1] == "none":
 831     default_backtrace_impl = "none"
 832     print(termcap.Yellow + termcap.Bold +
 833         "No suitable back trace implementation found." +
 834         termcap.Normal)
 835
 836 if not have_posix_clock:
 837     print("Can't find library for POSIX clocks.")
 838
 839 # Check for <fenv.h> (C99 FP environment control)
 840 have_fenv = conf.CheckHeader('fenv.h', '<>')
 841 if not have_fenv:
 842     print("Warning: Header file <fenv.h> not found.")
 843     print("         This host has no IEEE FP rounding mode control.")
 844
 845 # Check for <png.h> (libpng library needed if wanting to dump
 846 # frame buffer image in png format)
 847 have_png = conf.CheckHeader('png.h', '<>')
 848 if not have_png:
 849     print("Warning: Header file <png.h> not found.")
 850     print("         This host has no libpng library.")
 851     print("         Disabling support for PNG framebuffers.")
 852
 853 # Check if we should enable KVM-based hardware virtualization. The API
 854 # we rely on exists since version 2.6.36 of the kernel, but somehow
 855 # the KVM_API_VERSION does not reflect the change. We test for one of
 856 # the types as a fall back.
 857 have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
 858 if not have_kvm:
 859     print("Info: Compatible header file <linux/kvm.h> not found, "
 860           "disabling KVM support.")
 861
 862 # Check if the TUN/TAP driver is available.
 863 have_tuntap = conf.CheckHeader('linux/if_tun.h', '<>')
 864 if not have_tuntap:
 865     print("Info: Compatible header file <linux/if_tun.h> not found.")
 866
 867 # x86 needs support for xsave. We test for the structure here since we
 868 # won't be able to run new tests by the time we know which ISA we're
 869 # targeting.
 870 have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
 871                                     '#include <linux/kvm.h>') != 0
 872
 873 # Check if the requested target ISA is compatible with the host
 874 def is_isa_kvm_compatible(isa):
 875     try:
 876         import platform
 877         host_isa = platform.machine()
 878     except:
 879         print("Warning: Failed to determine host ISA.")
 880         return False
 881
 882     if not have_posix_timers:
 883         print("Warning: Can not enable KVM, host seems to lack support "
 884               "for POSIX timers")
 885         return False
 886
 887     if isa == "arm":
 888         return host_isa in ( "armv7l", "aarch64" )
 889     elif isa == "x86":
 890         if host_isa != "x86_64":
 891             return False
 892
 893         if not have_kvm_xsave:
 894             print("KVM on x86 requires xsave support in kernel headers.")
 895             return False
 896
 897         return True
 898     else:
 899         return False
 900
 901
 902 # Check if the exclude_host attribute is available. We want this to
 903 # get accurate instruction counts in KVM.
 904 main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
 905     'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
 906
 907
 908 ######################################################################
 909 #
 910 # Finish the configuration
 911 #
 912 main = conf.Finish()
 913
 914 ######################################################################
 915 #
 916 # Collect all non-global variables
 917 #
 918
 919 # Define the universe of supported ISAs
 920 all_isa_list = [ ]
 921 all_gpu_isa_list = [ ]
 922 Export('all_isa_list')
 923 Export('all_gpu_isa_list')
 924
 925 class CpuModel(object):
 926     '''The CpuModel class encapsulates everything the ISA parser needs to
 927     know about a particular CPU model.'''
 928
 929     # Dict of available CPU model objects.  Accessible as CpuModel.dict.
 930     dict = {}
 931
 932     # Constructor.  Automatically adds models to CpuModel.dict.
 933     def __init__(self, name, default=False):
 934         self.name = name           # name of model
 935
 936         # This cpu is enabled by default
 937         self.default = default
 938
 939         # Add self to dict
 940         if name in CpuModel.dict:
 941             raise AttributeError, "CpuModel '%s' already registered" % name
 942         CpuModel.dict[name] = self
 943
 944 Export('CpuModel')
 945
 946 # Sticky variables get saved in the variables file so they persist from
 947 # one invocation to the next (unless overridden, in which case the new
 948 # value becomes sticky).
 949 sticky_vars = Variables(args=ARGUMENTS)
 950 Export('sticky_vars')
 951
 952 # Sticky variables that should be exported
 953 export_vars = []
 954 Export('export_vars')
 955
 956 # For Ruby
 957 all_protocols = []
 958 Export('all_protocols')
 959 protocol_dirs = []
 960 Export('protocol_dirs')
 961 slicc_includes = []
 962 Export('slicc_includes')
 963
 964 # Walk the tree and execute all SConsopts scripts that wil add to the
 965 # above variables
 966 if GetOption('verbose'):
 967     print("Reading SConsopts")
 968 for bdir in [ base_dir ] + extras_dir_list:
 969     if not isdir(bdir):
 970         print("Error: directory '%s' does not exist" % bdir)
 971         Exit(1)
 972     for root, dirs, files in os.walk(bdir):
 973         if 'SConsopts' in files:
 974             if GetOption('verbose'):
 975                 print("Reading", joinpath(root, 'SConsopts'))
 976             SConscript(joinpath(root, 'SConsopts'))
 977
 978 all_isa_list.sort()
 979 all_gpu_isa_list.sort()
 980
 981 sticky_vars.AddVariables(
 982     EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
 983     EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
 984     ListVariable('CPU_MODELS', 'CPU models',
 985                  sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
 986                  sorted(CpuModel.dict.keys())),
 987     BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
 988                  False),
 989     BoolVariable('SS_COMPATIBLE_FP',
 990                  'Make floating-point results compatible with SimpleScalar',
 991                  False),
 992     BoolVariable('USE_SSE2',
 993                  'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
 994                  False),
 995     BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
 996     BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
 997     BoolVariable('USE_PNG',  'Enable support for PNG images', have_png),
 998     BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
 999                  False),
1000     BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1001                  have_kvm),
1002     BoolVariable('USE_TUNTAP',
1003                  'Enable using a tap device to bridge to the host network',
1004                  have_tuntap),
1005     BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1006     EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1007                   all_protocols),
1008     EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1009                  backtrace_impls[-1], backtrace_impls)
1010     )
1011
1012 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1013 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1014                 'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP',
1015                 'PROTOCOL', 'HAVE_PROTOBUF', 'HAVE_PERF_ATTR_EXCLUDE_HOST',
1016                 'USE_PNG']
1017
1018 ###################################################
1019 #
1020 # Define a SCons builder for configuration flag headers.
1021 #
1022 ###################################################
1023
1024 # This function generates a config header file that #defines the
1025 # variable symbol to the current variable setting (0 or 1).  The source
1026 # operands are the name of the variable and a Value node containing the
1027 # value of the variable.
1028 def build_config_file(target, source, env):
1029     (variable, value) = [s.get_contents() for s in source]
1030     f = file(str(target[0]), 'w')
1031     print('#define', variable, value, file=f)
1032     f.close()
1033     return None
1034
1035 # Combine the two functions into a scons Action object.
1036 config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1037
1038 # The emitter munges the source & target node lists to reflect what
1039 # we're really doing.
1040 def config_emitter(target, source, env):
1041     # extract variable name from Builder arg
1042     variable = str(target[0])
1043     # True target is config header file
1044     target = joinpath('config', variable.lower() + '.hh')
1045     val = env[variable]
1046     if isinstance(val, bool):
1047         # Force value to 0/1
1048         val = int(val)
1049     elif isinstance(val, str):
1050         val = '"' + val + '"'
1051
1052     # Sources are variable name & value (packaged in SCons Value nodes)
1053     return ([target], [Value(variable), Value(val)])
1054
1055 config_builder = Builder(emitter = config_emitter, action = config_action)
1056
1057 main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1058
1059 ###################################################
1060 #
1061 # Builders for static and shared partially linked object files.
1062 #
1063 ###################################################
1064
1065 partial_static_builder = Builder(action=SCons.Defaults.LinkAction,
1066                                  src_suffix='$OBJSUFFIX',
1067                                  src_builder=['StaticObject', 'Object'],
1068                                  LINKFLAGS='$PLINKFLAGS',
1069                                  LIBS='')
1070
1071 def partial_shared_emitter(target, source, env):
1072     for tgt in target:
1073         tgt.attributes.shared = 1
1074     return (target, source)
1075 partial_shared_builder = Builder(action=SCons.Defaults.ShLinkAction,
1076                                  emitter=partial_shared_emitter,
1077                                  src_suffix='$SHOBJSUFFIX',
1078                                  src_builder='SharedObject',
1079                                  SHLINKFLAGS='$PSHLINKFLAGS',
1080                                  LIBS='')
1081
1082 main.Append(BUILDERS = { 'PartialShared' : partial_shared_builder,
1083                          'PartialStatic' : partial_static_builder })
1084
1085 # builds in ext are shared across all configs in the build root.
1086 ext_dir = abspath(joinpath(str(main.root), 'ext'))
1087 ext_build_dirs = []
1088 for root, dirs, files in os.walk(ext_dir):
1089     if 'SConscript' in files:
1090         build_dir = os.path.relpath(root, ext_dir)
1091         ext_build_dirs.append(build_dir)
1092         main.SConscript(joinpath(root, 'SConscript'),
1093                         variant_dir=joinpath(build_root, build_dir))
1094
1095 main.Prepend(CPPPATH=Dir('ext/pybind11/include/'))
1096
1097 ###################################################
1098 #
1099 # This builder and wrapper method are used to set up a directory with
1100 # switching headers. Those are headers which are in a generic location and
1101 # that include more specific headers from a directory chosen at build time
1102 # based on the current build settings.
1103 #
1104 ###################################################
1105
1106 def build_switching_header(target, source, env):
1107     path = str(target[0])
1108     subdir = str(source[0])
1109     dp, fp = os.path.split(path)
1110     dp = os.path.relpath(os.path.realpath(dp),
1111                          os.path.realpath(env['BUILDDIR']))
1112     with open(path, 'w') as hdr:
1113         print('#include "%s/%s/%s"' % (dp, subdir, fp), file=hdr)
1114
1115 switching_header_action = MakeAction(build_switching_header,
1116                                      Transform('GENERATE'))
1117
1118 switching_header_builder = Builder(action=switching_header_action,
1119                                    source_factory=Value,
1120                                    single_source=True)
1121
1122 main.Append(BUILDERS = { 'SwitchingHeader': switching_header_builder })
1123
1124 def switching_headers(self, headers, source):
1125     for header in headers:
1126         self.SwitchingHeader(header, source)
1127
1128 main.AddMethod(switching_headers, 'SwitchingHeaders')
1129
1130 ###################################################
1131 #
1132 # Define build environments for selected configurations.
1133 #
1134 ###################################################
1135
1136 for variant_path in variant_paths:
1137     if not GetOption('silent'):
1138         print("Building in", variant_path)
1139
1140     # Make a copy of the build-root environment to use for this config.
1141     env = main.Clone()
1142     env['BUILDDIR'] = variant_path
1143
1144     # variant_dir is the tail component of build path, and is used to
1145     # determine the build parameters (e.g., 'ALPHA_SE')
1146     (build_root, variant_dir) = splitpath(variant_path)
1147
1148     # Set env variables according to the build directory config.
1149     sticky_vars.files = []
1150     # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1151     # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1152     # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1153     current_vars_file = joinpath(build_root, 'variables', variant_dir)
1154     if isfile(current_vars_file):
1155         sticky_vars.files.append(current_vars_file)
1156         if not GetOption('silent'):
1157             print("Using saved variables file %s" % current_vars_file)
1158     elif variant_dir in ext_build_dirs:
1159         # Things in ext are built without a variant directory.
1160         continue
1161     else:
1162         # Build dir-specific variables file doesn't exist.
1163
1164         # Make sure the directory is there so we can create it later
1165         opt_dir = dirname(current_vars_file)
1166         if not isdir(opt_dir):
1167             mkdir(opt_dir)
1168
1169         # Get default build variables from source tree.  Variables are
1170         # normally determined by name of $VARIANT_DIR, but can be
1171         # overridden by '--default=' arg on command line.
1172         default = GetOption('default')
1173         opts_dir = joinpath(main.root.abspath, 'build_opts')
1174         if default:
1175             default_vars_files = [joinpath(build_root, 'variables', default),
1176                                   joinpath(opts_dir, default)]
1177         else:
1178             default_vars_files = [joinpath(opts_dir, variant_dir)]
1179         existing_files = filter(isfile, default_vars_files)
1180         if existing_files:
1181             default_vars_file = existing_files[0]
1182             sticky_vars.files.append(default_vars_file)
1183             print("Variables file %s not found,\n  using defaults in %s"
1184                   % (current_vars_file, default_vars_file))
1185         else:
1186             print("Error: cannot find variables file %s or "
1187                   "default file(s) %s"
1188                   % (current_vars_file, ' or '.join(default_vars_files)))
1189             Exit(1)
1190
1191     # Apply current variable settings to env
1192     sticky_vars.Update(env)
1193
1194     help_texts["local_vars"] += \
1195         "Build variables for %s:\n" % variant_dir \
1196                  + sticky_vars.GenerateHelpText(env)
1197
1198     # Process variable settings.
1199
1200     if not have_fenv and env['USE_FENV']:
1201         print("Warning: <fenv.h> not available; "
1202               "forcing USE_FENV to False in", variant_dir + ".")
1203         env['USE_FENV'] = False
1204
1205     if not env['USE_FENV']:
1206         print("Warning: No IEEE FP rounding mode control in",
1207               variant_dir + ".")
1208         print("         FP results may deviate slightly from other platforms.")
1209
1210     if not have_png and env['USE_PNG']:
1211         print("Warning: <png.h> not available; "
1212               "forcing USE_PNG to False in", variant_dir + ".")
1213         env['USE_PNG'] = False
1214
1215     if env['USE_PNG']:
1216         env.Append(LIBS=['png'])
1217
1218     if env['EFENCE']:
1219         env.Append(LIBS=['efence'])
1220
1221     if env['USE_KVM']:
1222         if not have_kvm:
1223             print("Warning: Can not enable KVM, host seems to "
1224                   "lack KVM support")
1225             env['USE_KVM'] = False
1226         elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1227             print("Info: KVM support disabled due to unsupported host and "
1228                   "target ISA combination")
1229             env['USE_KVM'] = False
1230
1231     if env['USE_TUNTAP']:
1232         if not have_tuntap:
1233             print("Warning: Can't connect EtherTap with a tap device.")
1234             env['USE_TUNTAP'] = False
1235
1236     if env['BUILD_GPU']:
1237         env.Append(CPPDEFINES=['BUILD_GPU'])
1238
1239     # Warn about missing optional functionality
1240     if env['USE_KVM']:
1241         if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1242             print("Warning: perf_event headers lack support for the "
1243                   "exclude_host attribute. KVM instruction counts will "
1244                   "be inaccurate.")
1245
1246     # Save sticky variable settings back to current variables file
1247     sticky_vars.Save(current_vars_file, env)
1248
1249     if env['USE_SSE2']:
1250         env.Append(CCFLAGS=['-msse2'])
1251
1252     # The src/SConscript file sets up the build rules in 'env' according
1253     # to the configured variables.  It returns a list of environments,
1254     # one for each variant build (debug, opt, etc.)
1255     SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1256
1257 # base help text
1258 Help('''
1259 Usage: scons [scons options] [build variables] [target(s)]
1260
1261 Extra scons options:
1262 %(options)s
1263
1264 Global build variables:
1265 %(global_vars)s
1266
1267 %(local_vars)s
1268 ''' % help_texts)