SConstruct revision 11235
1360SN/A# -*- mode:python -*-
21458SN/A
3360SN/A# Copyright (c) 2013, 2015 ARM Limited
4360SN/A# All rights reserved.
5360SN/A#
6360SN/A# The license below extends only to copyright in the software and shall
7360SN/A# not be construed as granting a license to any other intellectual
8360SN/A# property including but not limited to intellectual property relating
9360SN/A# to a hardware implementation of the functionality of the software
10360SN/A# licensed hereunder.  You may use the software subject to the license
11360SN/A# terms below provided that you ensure that this notice is replicated
12360SN/A# unmodified and in its entirety in all distributions of the software,
13360SN/A# modified or unmodified, in source code or in binary form.
14360SN/A#
15360SN/A# Copyright (c) 2011 Advanced Micro Devices, Inc.
16360SN/A# Copyright (c) 2009 The Hewlett-Packard Development Company
17360SN/A# Copyright (c) 2004-2005 The Regents of The University of Michigan
18360SN/A# All rights reserved.
19360SN/A#
20360SN/A# Redistribution and use in source and binary forms, with or without
21360SN/A# modification, are permitted provided that the following conditions are
22360SN/A# met: redistributions of source code must retain the above copyright
23360SN/A# notice, this list of conditions and the following disclaimer;
24360SN/A# redistributions in binary form must reproduce the above copyright
25360SN/A# notice, this list of conditions and the following disclaimer in the
26360SN/A# documentation and/or other materials provided with the distribution;
272665Ssaidi@eecs.umich.edu# neither the name of the copyright holders nor the names of its
282665Ssaidi@eecs.umich.edu# contributors may be used to endorse or promote products derived from
292665Ssaidi@eecs.umich.edu# this software without specific prior written permission.
30360SN/A#
31360SN/A# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
322093SN/A# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33360SN/A# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34360SN/A# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35360SN/A# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36360SN/A# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37360SN/A# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38360SN/A# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
392474SN/A# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40360SN/A# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
412680Sktlim@umich.edu# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
421717SN/A#
432474SN/A# Authors: Steve Reinhardt
44360SN/A#          Nathan Binkert
456029Ssteve.reinhardt@amd.com
46360SN/A###################################################
472667Sstever@eecs.umich.edu#
48360SN/A# SCons top-level build description (SConstruct) file.
49360SN/A#
502107SN/A# While in this directory ('gem5'), just type 'scons' to build the default
51360SN/A# configuration (see below), or type 'scons build/<CONFIG>/<binary>'
52360SN/A# to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
533114Sgblack@eecs.umich.edu# the optimized full-system version).
54360SN/A#
556111Ssteve.reinhardt@amd.com# You can build gem5 in a different directory as long as there is a
566111Ssteve.reinhardt@amd.com# 'build/<CONFIG>' somewhere along the target path.  The build system
576111Ssteve.reinhardt@amd.com# expects that all configs under the same build directory are being
585958Sgblack@eecs.umich.edu# built for the same host system.
595958Sgblack@eecs.umich.edu#
60360SN/A# Examples:
612680Sktlim@umich.edu#
62360SN/A#   The following two commands are equivalent.  The '-u' option tells
632495SN/A#   scons to search up the directory tree for this SConstruct file.
642680Sktlim@umich.edu#   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
65360SN/A#   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
661450SN/A#
675958Sgblack@eecs.umich.edu#   The following two commands are equivalent and demonstrate building
68360SN/A#   in a directory outside of the source tree.  The '-C' option tells
69360SN/A#   scons to chdir to the specified directory to find this SConstruct
70360SN/A#   file.
711450SN/A#   % cd <path-to-src>/gem5 ; scons /local/foo/build/ALPHA/gem5.debug
723114Sgblack@eecs.umich.edu#   % cd /local/foo/build/ALPHA; scons -C <path-to-src>/gem5 gem5.debug
732680Sktlim@umich.edu#
74360SN/A# You can use 'scons -H' to print scons options.  If you're in this
751969SN/A# 'gem5' directory (or use -u or -C to tell scons where to find this
762484SN/A# file), you can use 'scons -h' to print all the gem5-specific build
772484SN/A# options as well.
78360SN/A#
79360SN/A###################################################
80360SN/A
811450SN/A# Check for recent-enough Python and SCons versions.
823114Sgblack@eecs.umich.edutry:
832680Sktlim@umich.edu    # Really old versions of scons only take two options for the
84360SN/A    # function, so check once without the revision and once with the
851969SN/A    # revision, the first instance will fail for stuff other than
865958Sgblack@eecs.umich.edu    # 0.98, and the second will fail for 0.98.0
87360SN/A    EnsureSConsVersion(0, 98)
881458SN/A    EnsureSConsVersion(0, 98, 1)
89360SN/Aexcept SystemExit, e:
90360SN/A    print """
91360SN/AFor more details, see:
921450SN/A    http://gem5.org/Dependencies
933114Sgblack@eecs.umich.edu"""
942680Sktlim@umich.edu    raise
95360SN/A
966029Ssteve.reinhardt@amd.com# We ensure the python version early because because python-config
976029Ssteve.reinhardt@amd.com# requires python 2.5
985958Sgblack@eecs.umich.edutry:
996029Ssteve.reinhardt@amd.com    EnsurePythonVersion(2, 5)
1006029Ssteve.reinhardt@amd.comexcept SystemExit, e:
1016029Ssteve.reinhardt@amd.com    print """
1026029Ssteve.reinhardt@amd.comYou can use a non-default installation of the Python interpreter by
1032834Sksewell@umich.edurearranging your PATH so that scons finds the non-default 'python' and
104360SN/A'python-config' first.
1051458SN/A
106360SN/AFor more details, see:
107360SN/A    http://gem5.org/wiki/index.php/Using_a_non-default_Python_installation
108360SN/A"""
1091450SN/A    raise
1106109Ssanchezd@stanford.edu
1116109Ssanchezd@stanford.edu# Global Python includes
1126109Ssanchezd@stanford.eduimport itertools
1136109Ssanchezd@stanford.eduimport os
1146109Ssanchezd@stanford.eduimport re
1156109Ssanchezd@stanford.eduimport subprocess
1166109Ssanchezd@stanford.eduimport sys
1176109Ssanchezd@stanford.edu
1186109Ssanchezd@stanford.edufrom os import mkdir, environ
1196109Ssanchezd@stanford.edufrom os.path import abspath, basename, dirname, expanduser, normpath
1206109Ssanchezd@stanford.edufrom os.path import exists,  isdir, isfile
1216109Ssanchezd@stanford.edufrom os.path import join as joinpath, split as splitpath
1226109Ssanchezd@stanford.edu
1233114Sgblack@eecs.umich.edu# SCons includes
124360SN/Aimport SCons
1252107SN/Aimport SCons.Node
126360SN/A
127360SN/Aextra_python_paths = [
128360SN/A    Dir('src/python').srcnode().abspath, # gem5 includes
1291450SN/A    Dir('ext/ply').srcnode().abspath, # ply is used by several files
1305748SSteve.Reinhardt@amd.com    ]
131360SN/A
132360SN/Asys.path[1:1] = extra_python_paths
1335958Sgblack@eecs.umich.edu
1345748SSteve.Reinhardt@amd.comfrom m5.util import compareVersions, readCommand
1355748SSteve.Reinhardt@amd.comfrom m5.util.terminal import get_termcap
1365748SSteve.Reinhardt@amd.com
1375748SSteve.Reinhardt@amd.comhelp_texts = {
1385748SSteve.Reinhardt@amd.com    "options" : "",
1395748SSteve.Reinhardt@amd.com    "global_vars" : "",
1405748SSteve.Reinhardt@amd.com    "local_vars" : ""
1415748SSteve.Reinhardt@amd.com}
1422474SN/A
1432474SN/AExport("help_texts")
1445748SSteve.Reinhardt@amd.com
1452474SN/A
1462474SN/A# There's a bug in scons in that (1) by default, the help texts from
1472474SN/A# AddOption() are supposed to be displayed when you type 'scons -h'
1481450SN/A# and (2) you can override the help displayed by 'scons -h' using the
1495748SSteve.Reinhardt@amd.com# Help() function, but these two features are incompatible: once
1505748SSteve.Reinhardt@amd.com# you've overridden the help text using Help(), there's no way to get
1511458SN/A# at the help texts from AddOptions.  See:
1521458SN/A#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
153360SN/A#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
154360SN/A# This hack lets us extract the help text from AddOptions and
155360SN/A# re-inject it via Help().  Ideally someday this bug will be fixed and
1561450SN/A# we can just use AddOption directly.
1573114Sgblack@eecs.umich.edudef AddLocalOption(*args, **kwargs):
158360SN/A    col_width = 30
1595958Sgblack@eecs.umich.edu
1601970SN/A    help = "  " + ", ".join(args)
1611970SN/A    if "help" in kwargs:
1621970SN/A        length = len(help)
1631970SN/A        if length >= col_width:
164360SN/A            help += "\n" + " " * col_width
165360SN/A        else:
166360SN/A            help += " " * (col_width - length)
1671450SN/A        help += kwargs["help"]
1683114Sgblack@eecs.umich.edu    help_texts["options"] += help + "\n"
169360SN/A
1705958Sgblack@eecs.umich.edu    AddOption(*args, **kwargs)
1715958Sgblack@eecs.umich.edu
1725958Sgblack@eecs.umich.eduAddLocalOption('--colors', dest='use_colors', action='store_true',
173360SN/A               help="Add color to abbreviated scons output")
174360SN/AAddLocalOption('--no-colors', dest='use_colors', action='store_false',
175360SN/A               help="Don't add color to abbreviated scons output")
176360SN/AAddLocalOption('--with-cxx-config', dest='with_cxx_config',
1772680Sktlim@umich.edu               action='store_true',
178360SN/A               help="Build with support for C++-based configuration")
1791458SN/AAddLocalOption('--default', dest='default', type='string', action='store',
180360SN/A               help='Override which build_opts file to use for defaults')
181360SN/AAddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
1821450SN/A               help='Disable style checking hooks')
1833114Sgblack@eecs.umich.eduAddLocalOption('--no-lto', dest='no_lto', action='store_true',
184360SN/A               help='Disable Link-Time Optimization for fast')
1855958Sgblack@eecs.umich.eduAddLocalOption('--update-ref', dest='update_ref', action='store_true',
1865958Sgblack@eecs.umich.edu               help='Update test reference outputs')
1875958Sgblack@eecs.umich.eduAddLocalOption('--verbose', dest='verbose', action='store_true',
188360SN/A               help='Print full tool command lines')
1892680Sktlim@umich.eduAddLocalOption('--without-python', dest='without_python',
190360SN/A               action='store_true',
191360SN/A               help='Build without Python configuration support')
192360SN/AAddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
193360SN/A               action='store_true',
194360SN/A               help='Disable linking against tcmalloc')
1951458SN/AAddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
196360SN/A               help='Build with Undefined Behavior Sanitizer if available')
197360SN/A
198360SN/Atermcap = get_termcap(GetOption('use_colors'))
1991450SN/A
2003114Sgblack@eecs.umich.edu########################################################################
201360SN/A#
2025958Sgblack@eecs.umich.edu# Set up the main build environment.
2035958Sgblack@eecs.umich.edu#
2045958Sgblack@eecs.umich.edu########################################################################
205360SN/A
206360SN/A# export TERM so that clang reports errors in color
207360SN/Ause_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH',
2081458SN/A                 'LIBRARY_PATH', 'PATH', 'PKG_CONFIG_PATH', 'PROTOC',
209360SN/A                 'PYTHONPATH', 'RANLIB', 'SWIG', 'TERM' ])
210360SN/A
211360SN/Ause_prefixes = [
2121450SN/A    "CCACHE_",         # ccache (caching compiler wrapper) configuration
2134118Sgblack@eecs.umich.edu    "CCC_",            # clang static analyzer configuration
2144118Sgblack@eecs.umich.edu    "DISTCC_",         # distcc (distributed compiler wrapper) configuration
2155958Sgblack@eecs.umich.edu    "INCLUDE_SERVER_", # distcc pump server settings
2165958Sgblack@eecs.umich.edu    "M5",              # M5 configuration (e.g., path to kernels)
2175958Sgblack@eecs.umich.edu    ]
2185958Sgblack@eecs.umich.edu
2195958Sgblack@eecs.umich.eduuse_env = {}
2204118Sgblack@eecs.umich.edufor key,val in sorted(os.environ.iteritems()):
2214118Sgblack@eecs.umich.edu    if key in use_vars or \
2224118Sgblack@eecs.umich.edu            any([key.startswith(prefix) for prefix in use_prefixes]):
2234118Sgblack@eecs.umich.edu        use_env[key] = val
2244118Sgblack@eecs.umich.edu
2254118Sgblack@eecs.umich.edu# Tell scons to avoid implicit command dependencies to avoid issues
2264118Sgblack@eecs.umich.edu# with the param wrappes being compiled twice (see
2274118Sgblack@eecs.umich.edu# http://scons.tigris.org/issues/show_bug.cgi?id=2811)
2284118Sgblack@eecs.umich.edumain = Environment(ENV=use_env, IMPLICIT_COMMAND_DEPENDENCIES=0)
2294118Sgblack@eecs.umich.edumain.Decider('MD5-timestamp')
2306111Ssteve.reinhardt@amd.commain.root = Dir(".")         # The current directory (where this file lives).
2316111Ssteve.reinhardt@amd.commain.srcdir = Dir("src")     # The source directory
2326111Ssteve.reinhardt@amd.com
2336111Ssteve.reinhardt@amd.commain_dict_keys = main.Dictionary().keys()
2344118Sgblack@eecs.umich.edu
2354118Sgblack@eecs.umich.edu# Check that we have a C/C++ compiler
2364118Sgblack@eecs.umich.eduif not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
2374118Sgblack@eecs.umich.edu    print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
2384118Sgblack@eecs.umich.edu    Exit(1)
2394118Sgblack@eecs.umich.edu
2404118Sgblack@eecs.umich.edu# Check that swig is present
2414118Sgblack@eecs.umich.eduif not 'SWIG' in main_dict_keys:
2424118Sgblack@eecs.umich.edu    print "swig is not installed (package swig on Ubuntu and RedHat)"
2434118Sgblack@eecs.umich.edu    Exit(1)
2444118Sgblack@eecs.umich.edu
2454118Sgblack@eecs.umich.edu# add useful python code PYTHONPATH so it can be used by subprocesses
2463114Sgblack@eecs.umich.edu# as well
247360SN/Amain.AppendENVPath('PYTHONPATH', extra_python_paths)
248360SN/A
2491458SN/A########################################################################
250360SN/A#
251360SN/A# Mercurial Stuff.
252360SN/A#
253360SN/A# If the gem5 directory is a mercurial repository, we should do some
254360SN/A# extra things.
2551450SN/A#
2563114Sgblack@eecs.umich.edu########################################################################
257360SN/A
2585958Sgblack@eecs.umich.eduhgdir = main.root.Dir(".hg")
2595958Sgblack@eecs.umich.edu
260360SN/Amercurial_style_message = """
261360SN/AYou're missing the gem5 style hook, which automatically checks your code
262360SN/Aagainst the gem5 style rules on hg commit and qrefresh commands.  This
2632680Sktlim@umich.eduscript will now install the hook in your .hg/hgrc file.
264360SN/APress enter to continue, or ctrl-c to abort: """
2651458SN/A
266360SN/Amercurial_style_hook = """
267360SN/A# The following lines were automatically added by gem5/SConstruct
2681450SN/A# to provide the gem5 style-checking hooks
2695513SMichael.Adler@intel.com[extensions]
2705513SMichael.Adler@intel.comstyle = %s/util/style.py
2715513SMichael.Adler@intel.com
2725958Sgblack@eecs.umich.edu[hooks]
2735958Sgblack@eecs.umich.edupretxncommit.style = python:style.check_style
2745513SMichael.Adler@intel.compre-qrefresh.style = python:style.check_style
2755513SMichael.Adler@intel.com# End of SConstruct additions
2765513SMichael.Adler@intel.com
2775513SMichael.Adler@intel.com""" % (main.root.abspath)
2785513SMichael.Adler@intel.com
2795513SMichael.Adler@intel.commercurial_lib_not_found = """
2805513SMichael.Adler@intel.comMercurial libraries cannot be found, ignoring style hook.  If
2815513SMichael.Adler@intel.comyou are a gem5 developer, please fix this and run the style
2825513SMichael.Adler@intel.comhook. It is important.
2835513SMichael.Adler@intel.com"""
2845513SMichael.Adler@intel.com
2855513SMichael.Adler@intel.com# Check for style hook and prompt for installation if it's not there.
2865513SMichael.Adler@intel.com# Skip this if --ignore-style was specified, there's no .hg dir to
2875513SMichael.Adler@intel.com# install a hook in, or there's no interactive terminal to prompt.
2885513SMichael.Adler@intel.comif not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
2895513SMichael.Adler@intel.com    style_hook = True
2905513SMichael.Adler@intel.com    try:
2915513SMichael.Adler@intel.com        from mercurial import ui
2925513SMichael.Adler@intel.com        ui = ui.ui()
2935513SMichael.Adler@intel.com        ui.readconfig(hgdir.File('hgrc').abspath)
2945513SMichael.Adler@intel.com        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
2955513SMichael.Adler@intel.com                     ui.config('hooks', 'pre-qrefresh.style', None)
2965513SMichael.Adler@intel.com    except ImportError:
2975513SMichael.Adler@intel.com        print mercurial_lib_not_found
2985513SMichael.Adler@intel.com
2995513SMichael.Adler@intel.com    if not style_hook:
3005513SMichael.Adler@intel.com        print mercurial_style_message,
3015513SMichael.Adler@intel.com        # continue unless user does ctrl-c/ctrl-d etc.
3025513SMichael.Adler@intel.com        try:
3035513SMichael.Adler@intel.com            raw_input()
3045513SMichael.Adler@intel.com        except:
3055958Sgblack@eecs.umich.edu            print "Input exception, exiting scons.\n"
3065513SMichael.Adler@intel.com            sys.exit(1)
3075513SMichael.Adler@intel.com        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
3085513SMichael.Adler@intel.com        print "Adding style hook to", hgrc_path, "\n"
3095513SMichael.Adler@intel.com        try:
3105513SMichael.Adler@intel.com            hgrc = open(hgrc_path, 'a')
3115958Sgblack@eecs.umich.edu            hgrc.write(mercurial_style_hook)
3125958Sgblack@eecs.umich.edu            hgrc.close()
3135513SMichael.Adler@intel.com        except:
3145513SMichael.Adler@intel.com            print "Error updating", hgrc_path
3155513SMichael.Adler@intel.com            sys.exit(1)
3165513SMichael.Adler@intel.com
3175513SMichael.Adler@intel.com
3185513SMichael.Adler@intel.com###################################################
3195513SMichael.Adler@intel.com#
3205513SMichael.Adler@intel.com# Figure out which configurations to set up based on the path(s) of
3215513SMichael.Adler@intel.com# the target(s).
3223114Sgblack@eecs.umich.edu#
323511SN/A###################################################
3241706SN/A
325360SN/A# Find default configuration & binary.
3265958Sgblack@eecs.umich.eduDefault(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
3271450SN/A
328511SN/A# helper function: find last occurrence of element in list
3293669Sbinkertn@umich.edudef rfind(l, elt, offs = -1):
3303669Sbinkertn@umich.edu    for i in range(len(l)+offs, 0, -1):
3313669Sbinkertn@umich.edu        if l[i] == elt:
332511SN/A            return i
3331458SN/A    raise ValueError, "element not found"
334511SN/A
335511SN/A# Take a list of paths (or SCons Nodes) and return a list with all
3365513SMichael.Adler@intel.com# paths made absolute and ~-expanded.  Paths will be interpreted
3375513SMichael.Adler@intel.com# relative to the launch directory unless a different root is provided
3385513SMichael.Adler@intel.comdef makePathListAbsolute(path_list, root=GetLaunchDir()):
3395513SMichael.Adler@intel.com    return [abspath(joinpath(root, expanduser(str(p))))
3405513SMichael.Adler@intel.com            for p in path_list]
3415513SMichael.Adler@intel.com
3425958Sgblack@eecs.umich.edu# Each target must have 'build' in the interior of the path; the
3435513SMichael.Adler@intel.com# directory below this will determine the build parameters.  For
3445513SMichael.Adler@intel.com# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
3455513SMichael.Adler@intel.com# recognize that ALPHA_SE specifies the configuration because it
3465513SMichael.Adler@intel.com# follow 'build' in the build path.
3475513SMichael.Adler@intel.com
3485958Sgblack@eecs.umich.edu# The funky assignment to "[:]" is needed to replace the list contents
3495513SMichael.Adler@intel.com# in place rather than reassign the symbol to a new list, which
3505513SMichael.Adler@intel.com# doesn't work (obviously!).
3515513SMichael.Adler@intel.comBUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
3525513SMichael.Adler@intel.com
3535513SMichael.Adler@intel.com# Generate a list of the unique build roots and configs that the
3541450SN/A# collected targets reference.
3553114Sgblack@eecs.umich.eduvariant_paths = []
356511SN/Abuild_root = None
3571706SN/Afor t in BUILD_TARGETS:
358511SN/A    path_dirs = t.split('/')
3595958Sgblack@eecs.umich.edu    try:
3601458SN/A        build_top = rfind(path_dirs, 'build', -2)
361511SN/A    except:
3621706SN/A        print "Error: no non-leaf 'build' dir found on target path", t
363511SN/A        Exit(1)
3645958Sgblack@eecs.umich.edu    this_build_root = joinpath('/',*path_dirs[:build_top+1])
3651458SN/A    if not build_root:
366511SN/A        build_root = this_build_root
3673669Sbinkertn@umich.edu    else:
3683669Sbinkertn@umich.edu        if this_build_root != build_root:
3693669Sbinkertn@umich.edu            print "Error: build targets not under same build root\n"\
3703669Sbinkertn@umich.edu                  "  %s\n  %s" % (build_root, this_build_root)
3711706SN/A            Exit(1)
3721458SN/A    variant_path = joinpath('/',*path_dirs[:build_top+2])
373511SN/A    if variant_path not in variant_paths:
374511SN/A        variant_paths.append(variant_path)
3751706SN/A
3763114Sgblack@eecs.umich.edu# Make sure build_root exists (might not if this is the first build there)
3771706SN/Aif not isdir(build_root):
3781706SN/A    mkdir(build_root)
3791706SN/Amain['BUILDROOT'] = build_root
3805958Sgblack@eecs.umich.edu
3811706SN/AExport('main')
3821706SN/A
3835958Sgblack@eecs.umich.edumain.SConsignFile(joinpath(build_root, "sconsign"))
3841706SN/A
3853669Sbinkertn@umich.edu# Default duplicate option is to use hard links, but this messes up
3863669Sbinkertn@umich.edu# when you use emacs to edit a file in the target dir, as emacs moves
3873669Sbinkertn@umich.edu# file to file~ then copies to file, breaking the link.  Symbolic
3881706SN/A# (soft) links work better.
3891706SN/Amain.SetOption('duplicate', 'soft-copy')
3901706SN/A
3911706SN/A#
3921706SN/A# Set up global sticky variables... these are common to an entire build
3936111Ssteve.reinhardt@amd.com# tree (not specific to a particular build like ALPHA_SE)
3946111Ssteve.reinhardt@amd.com#
3951706SN/A
3965958Sgblack@eecs.umich.eduglobal_vars_file = joinpath(build_root, 'variables.global')
3971706SN/A
3981706SN/Aglobal_vars = Variables(global_vars_file, args=ARGUMENTS)
3991706SN/A
4001706SN/Aglobal_vars.AddVariables(
4015958Sgblack@eecs.umich.edu    ('CC', 'C compiler', environ.get('CC', main['CC'])),
4021706SN/A    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
4031706SN/A    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
4041706SN/A    ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
4051706SN/A    ('BATCH', 'Use batch pool for build and tests', False),
4061999SN/A    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
4071999SN/A    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
4085513SMichael.Adler@intel.com    ('EXTRAS', 'Add extra directories to the compilation', '')
4095513SMichael.Adler@intel.com    )
4105513SMichael.Adler@intel.com
4115513SMichael.Adler@intel.com# Update main environment with values from ARGUMENTS & global_vars_file
4125513SMichael.Adler@intel.comglobal_vars.Update(main)
4135513SMichael.Adler@intel.comhelp_texts["global_vars"] += global_vars.GenerateHelpText(main)
4145513SMichael.Adler@intel.com
4155521Snate@binkert.org# Save sticky variable settings back to current variables file
4165513SMichael.Adler@intel.comglobal_vars.Save(global_vars_file, main)
4175513SMichael.Adler@intel.com
4185513SMichael.Adler@intel.com# Parse EXTRAS variable to build list of all directories where we're
4193114Sgblack@eecs.umich.edu# look for sources etc.  This list is exported as extras_dir_list.
4201999SN/Abase_dir = main.srcdir.abspath
4211999SN/Aif main['EXTRAS']:
4221999SN/A    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
4235958Sgblack@eecs.umich.eduelse:
4241999SN/A    extras_dir_list = []
4251999SN/A
4261999SN/AExport('base_dir')
4275958Sgblack@eecs.umich.eduExport('extras_dir_list')
4281999SN/A
4295958Sgblack@eecs.umich.edu# the ext directory should be on the #includes path
4301999SN/Amain.Append(CPPPATH=[Dir('ext')])
4311999SN/A
4323669Sbinkertn@umich.edudef strip_build_path(path, env):
4333669Sbinkertn@umich.edu    path = str(path)
4343669Sbinkertn@umich.edu    variant_base = env['BUILDROOT'] + os.path.sep
4351999SN/A    if path.startswith(variant_base):
4361999SN/A        path = path[len(variant_base):]
4371999SN/A    elif path.startswith('build/'):
4381999SN/A        path = path[6:]
4391999SN/A    return path
4403114Sgblack@eecs.umich.edu
4411999SN/A# Generate a string of the form:
4425958Sgblack@eecs.umich.edu#   common/path/prefix/src1, src2 -> tgt1, tgt2
4431999SN/A# to print while building.
4441999SN/Aclass Transform(object):
4451999SN/A    # all specific color settings should be here and nowhere else
4461999SN/A    tool_color = termcap.Normal
4471999SN/A    pfx_color = termcap.Yellow
4485958Sgblack@eecs.umich.edu    srcs_color = termcap.Yellow + termcap.Bold
4491999SN/A    arrow_color = termcap.Blue + termcap.Bold
4505958Sgblack@eecs.umich.edu    tgts_color = termcap.Yellow + termcap.Bold
4511999SN/A
4521999SN/A    def __init__(self, tool, max_sources=99):
4531999SN/A        self.format = self.tool_color + (" [%8s] " % tool) \
4541999SN/A                      + self.pfx_color + "%s" \
4551999SN/A                      + self.srcs_color + "%s" \
4562093SN/A                      + self.arrow_color + " -> " \
4572093SN/A                      + self.tgts_color + "%s" \
4582093SN/A                      + termcap.Normal
4593114Sgblack@eecs.umich.edu        self.max_sources = max_sources
4603079Sstever@eecs.umich.edu
4615958Sgblack@eecs.umich.edu    def __call__(self, target, source, env, for_signature=None):
4623079Sstever@eecs.umich.edu        # truncate source list according to max_sources param
4633079Sstever@eecs.umich.edu        source = source[0:self.max_sources]
4643079Sstever@eecs.umich.edu        def strip(f):
4655958Sgblack@eecs.umich.edu            return strip_build_path(str(f), env)
4665282Srstrong@cs.ucsd.edu        if len(source) > 0:
4673079Sstever@eecs.umich.edu            srcs = map(strip, source)
4686111Ssteve.reinhardt@amd.com        else:
4696111Ssteve.reinhardt@amd.com            srcs = ['']
4703079Sstever@eecs.umich.edu        tgts = map(strip, target)
4713079Sstever@eecs.umich.edu        # surprisingly, os.path.commonprefix is a dumb char-by-char string
4723079Sstever@eecs.umich.edu        # operation that has nothing to do with paths.
4733079Sstever@eecs.umich.edu        com_pfx = os.path.commonprefix(srcs + tgts)
4743114Sgblack@eecs.umich.edu        com_pfx_len = len(com_pfx)
4752680Sktlim@umich.edu        if com_pfx:
4762093SN/A            # do some cleanup and sanity checking on common prefix
4775958Sgblack@eecs.umich.edu            if com_pfx[-1] == ".":
4782093SN/A                # prefix matches all but file extension: ok
4792093SN/A                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
4802093SN/A                com_pfx = com_pfx[0:-1]
4812093SN/A            elif com_pfx[-1] == "/":
4825958Sgblack@eecs.umich.edu                # common prefix is directory path: OK
4832093SN/A                pass
4842093SN/A            else:
4852093SN/A                src0_len = len(srcs[0])
4862093SN/A                tgt0_len = len(tgts[0])
4872093SN/A                if src0_len == com_pfx_len:
4882093SN/A                    # source is a substring of target, OK
4892093SN/A                    pass
4902093SN/A                elif tgt0_len == com_pfx_len:
4912093SN/A                    # target is a substring of source, need to back up to
4922093SN/A                    # avoid empty string on RHS of arrow
4932093SN/A                    sep_idx = com_pfx.rfind(".")
4942093SN/A                    if sep_idx != -1:
4952093SN/A                        com_pfx = com_pfx[0:sep_idx]
4962093SN/A                    else:
4972093SN/A                        com_pfx = ''
4982093SN/A                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
4992093SN/A                    # still splitting at file extension: ok
5002093SN/A                    pass
5012093SN/A                else:
5022093SN/A                    # probably a fluke; ignore it
5032093SN/A                    com_pfx = ''
5042093SN/A        # recalculate length in case com_pfx was modified
5052093SN/A        com_pfx_len = len(com_pfx)
5062093SN/A        def fmt(files):
5072093SN/A            f = map(lambda s: s[com_pfx_len:], files)
5082093SN/A            return ', '.join(f)
5092093SN/A        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
5102093SN/A
5112093SN/AExport('Transform')
5122093SN/A
5132093SN/A# enable the regression script to use the termcap
5142093SN/Amain['TERMCAP'] = termcap
5152238SN/A
5163114Sgblack@eecs.umich.eduif GetOption('verbose'):
5172687Sksewell@umich.edu    def MakeAction(action, string, *args, **kwargs):
5182687Sksewell@umich.edu        return Action(action, *args, **kwargs)
5195958Sgblack@eecs.umich.eduelse:
5202687Sksewell@umich.edu    MakeAction = Action
5212687Sksewell@umich.edu    main['CCCOMSTR']        = Transform("CC")
5222687Sksewell@umich.edu    main['CXXCOMSTR']       = Transform("CXX")
5232687Sksewell@umich.edu    main['ASCOMSTR']        = Transform("AS")
5245958Sgblack@eecs.umich.edu    main['SWIGCOMSTR']      = Transform("SWIG")
5252687Sksewell@umich.edu    main['ARCOMSTR']        = Transform("AR", 0)
5262687Sksewell@umich.edu    main['LINKCOMSTR']      = Transform("LINK", 0)
5272687Sksewell@umich.edu    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
5282687Sksewell@umich.edu    main['M4COMSTR']        = Transform("M4")
5292687Sksewell@umich.edu    main['SHCCCOMSTR']      = Transform("SHCC")
5302687Sksewell@umich.edu    main['SHCXXCOMSTR']     = Transform("SHCXX")
5312687Sksewell@umich.eduExport('MakeAction')
5322687Sksewell@umich.edu
5332687Sksewell@umich.edu# Initialize the Link-Time Optimization (LTO) flags
5342687Sksewell@umich.edumain['LTO_CCFLAGS'] = []
5352687Sksewell@umich.edumain['LTO_LDFLAGS'] = []
5362687Sksewell@umich.edu
5372687Sksewell@umich.edu# According to the readme, tcmalloc works best if the compiler doesn't
5382687Sksewell@umich.edu# assume that we're using the builtin malloc and friends. These flags
5392687Sksewell@umich.edu# are compiler-specific, so we need to set them after we detect which
5402687Sksewell@umich.edu# compiler we're using.
5412687Sksewell@umich.edumain['TCMALLOC_CCFLAGS'] = []
5422687Sksewell@umich.edu
5432687Sksewell@umich.eduCXX_version = readCommand([main['CXX'],'--version'], exception=False)
5442687Sksewell@umich.eduCXX_V = readCommand([main['CXX'],'-V'], exception=False)
5453114Sgblack@eecs.umich.edu
5462680Sktlim@umich.edumain['GCC'] = CXX_version and CXX_version.find('g++') >= 0
5472238SN/Amain['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
5482238SN/Aif main['GCC'] + main['CLANG'] > 1:
5492238SN/A    print 'Error: How can we have two at the same time?'
5502093SN/A    Exit(1)
5512238SN/A
5522238SN/A# Set up default C++ compiler flags
5532238SN/Aif main['GCC'] or main['CLANG']:
5542238SN/A    # As gcc and clang share many flags, do the common parts here
5552238SN/A    main.Append(CCFLAGS=['-pipe'])
5565282Srstrong@cs.ucsd.edu    main.Append(CCFLAGS=['-fno-strict-aliasing'])
5575282Srstrong@cs.ucsd.edu    # Enable -Wall and then disable the few warnings that we
5582238SN/A    # consistently violate
5595282Srstrong@cs.ucsd.edu    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
5602238SN/A    # We always compile using C++11
5612238SN/A    main.Append(CXXFLAGS=['-std=c++11'])
5622680Sktlim@umich.edu    # Add selected sanity checks from -Wextra
5632238SN/A    main.Append(CXXFLAGS=['-Wmissing-field-initializers',
5642238SN/A                          '-Woverloaded-virtual'])
5652238SN/Aelse:
5662238SN/A    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
5672238SN/A    print "Don't know what compiler options to use for your compiler."
5683114Sgblack@eecs.umich.edu    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
5692680Sktlim@umich.edu    print termcap.Yellow + '       version:' + termcap.Normal,
5702238SN/A    if not CXX_version:
5712238SN/A        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
5722238SN/A               termcap.Normal
5732238SN/A    else:
5742238SN/A        print CXX_version.replace('\n', '<nl>')
5753114Sgblack@eecs.umich.edu    print "       If you're trying to use a compiler other than GCC"
5763114Sgblack@eecs.umich.edu    print "       or clang, there appears to be something wrong with your"
5772238SN/A    print "       environment."
5782238SN/A    print "       "
5792238SN/A    print "       If you are trying to use a compiler other than those listed"
5802238SN/A    print "       above you will need to ease fix SConstruct and "
5813114Sgblack@eecs.umich.edu    print "       src/SConscript to support that compiler."
5822680Sktlim@umich.edu    Exit(1)
5832238SN/A
5842238SN/Aif main['GCC']:
5852238SN/A    # Check for a supported version of gcc. >= 4.7 is chosen for its
5862238SN/A    # level of c++11 support. See
5872238SN/A    # http://gcc.gnu.org/projects/cxx0x.html for details.
5883114Sgblack@eecs.umich.edu    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
5895543Ssaidi@eecs.umich.edu    if compareVersions(gcc_version, "4.7") < 0:
5902238SN/A        print 'Error: gcc version 4.7 or newer required.'
5912238SN/A        print '       Installed version:', gcc_version
5922238SN/A        Exit(1)
5932238SN/A
5943114Sgblack@eecs.umich.edu    main['GCC_VERSION'] = gcc_version
5952680Sktlim@umich.edu
5962238SN/A    # gcc from version 4.8 and above generates "rep; ret" instructions
5972238SN/A    # to avoid performance penalties on certain AMD chips. Older
5983114Sgblack@eecs.umich.edu    # assemblers detect this as an error, "Error: expecting string
5993114Sgblack@eecs.umich.edu    # instruction after `rep'"
6002238SN/A    if compareVersions(gcc_version, "4.8") > 0:
6012238SN/A        as_version_raw = readCommand([main['AS'], '-v', '/dev/null'],
6022238SN/A                                     exception=False).split()
6032238SN/A
6043114Sgblack@eecs.umich.edu        # version strings may contain extra distro-specific
6052680Sktlim@umich.edu        # qualifiers, so play it safe and keep only what comes before
6062238SN/A        # the first hyphen
6072238SN/A        as_version = as_version_raw[-1].split('-')[0] if as_version_raw \
6085958Sgblack@eecs.umich.edu            else None
6092238SN/A
6102238SN/A        if not as_version or compareVersions(as_version, "2.23") < 0:
6112238SN/A            print termcap.Yellow + termcap.Bold + \
6122238SN/A                'Warning: This combination of gcc and binutils have' + \
6133114Sgblack@eecs.umich.edu                ' known incompatibilities.\n' + \
6142680Sktlim@umich.edu                '         If you encounter build problems, please update ' + \
6152238SN/A                'binutils to 2.23.' + \
6162238SN/A                termcap.Normal
6172238SN/A
6182238SN/A    # Make sure we warn if the user has requested to compile with the
6192238SN/A    # Undefined Benahvior Sanitizer and this version of gcc does not
6203114Sgblack@eecs.umich.edu    # support it.
6213114Sgblack@eecs.umich.edu    if GetOption('with_ubsan') and \
6222238SN/A            compareVersions(gcc_version, '4.9') < 0:
6232238SN/A        print termcap.Yellow + termcap.Bold + \
6242238SN/A            'Warning: UBSan is only supported using gcc 4.9 and later.' + \
6253114Sgblack@eecs.umich.edu            termcap.Normal
6262680Sktlim@umich.edu
6272238SN/A    # Add the appropriate Link-Time Optimization (LTO) flags
6283114Sgblack@eecs.umich.edu    # unless LTO is explicitly turned off. Note that these flags
6292238SN/A    # are only used by the fast target.
6302238SN/A    if not GetOption('no_lto'):
6312238SN/A        # Pass the LTO flag when compiling to produce GIMPLE
6323114Sgblack@eecs.umich.edu        # output, we merely create the flags here and only append
6332680Sktlim@umich.edu        # them later
6342238SN/A        main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
6355543Ssaidi@eecs.umich.edu
6362238SN/A        # Use the same amount of jobs for LTO as we are running
6372238SN/A        # scons with
6382238SN/A        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
6393114Sgblack@eecs.umich.edu
6402680Sktlim@umich.edu    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
6412238SN/A                                  '-fno-builtin-realloc', '-fno-builtin-free'])
6425543Ssaidi@eecs.umich.edu
6432238SN/Aelif main['CLANG']:
6442238SN/A    # Check for a supported version of clang, >= 3.1 is needed to
6452238SN/A    # support similar features as gcc 4.7. See
6463114Sgblack@eecs.umich.edu    # http://clang.llvm.org/cxx_status.html for details
6472680Sktlim@umich.edu    clang_version_re = re.compile(".* version (\d+\.\d+)")
6482238SN/A    clang_version_match = clang_version_re.search(CXX_version)
6493114Sgblack@eecs.umich.edu    if (clang_version_match):
6502238SN/A        clang_version = clang_version_match.groups()[0]
6512238SN/A        if compareVersions(clang_version, "3.1") < 0:
6522238SN/A            print 'Error: clang version 3.1 or newer required.'
6533114Sgblack@eecs.umich.edu            print '       Installed version:', clang_version
6542680Sktlim@umich.edu            Exit(1)
6552238SN/A    else:
6563114Sgblack@eecs.umich.edu        print 'Error: Unable to determine clang version.'
6572238SN/A        Exit(1)
6582238SN/A
6592238SN/A    # clang has a few additional warnings that we disable,
6606109Ssanchezd@stanford.edu    # tautological comparisons are allowed due to unsigned integers
6616109Ssanchezd@stanford.edu    # being compared to constants that happen to be 0, and extraneous
6626109Ssanchezd@stanford.edu    # parantheses are allowed due to Ruby's printing of the AST,
6636109Ssanchezd@stanford.edu    # finally self assignments are allowed as the generated CPU code
6646109Ssanchezd@stanford.edu    # is relying on this
6656110Ssteve.reinhardt@amd.com    main.Append(CCFLAGS=['-Wno-tautological-compare',
6666111Ssteve.reinhardt@amd.com                         '-Wno-parentheses',
6676111Ssteve.reinhardt@amd.com                         '-Wno-self-assign',
6686109Ssanchezd@stanford.edu                         # Some versions of libstdc++ (4.8?) seem to
6696109Ssanchezd@stanford.edu                         # use struct hash and class hash
6706110Ssteve.reinhardt@amd.com                         # interchangeably.
6716111Ssteve.reinhardt@amd.com                         '-Wno-mismatched-tags',
6726111Ssteve.reinhardt@amd.com                         ])
6736111Ssteve.reinhardt@amd.com
6746111Ssteve.reinhardt@amd.com    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
6756109Ssanchezd@stanford.edu
6766109Ssanchezd@stanford.edu    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
6776111Ssteve.reinhardt@amd.com    # opposed to libstdc++, as the later is dated.
6786109Ssanchezd@stanford.edu    if sys.platform == "darwin":
6796109Ssanchezd@stanford.edu        main.Append(CXXFLAGS=['-stdlib=libc++'])
6806109Ssanchezd@stanford.edu        main.Append(LIBS=['c++'])
6816109Ssanchezd@stanford.edu
6826109Ssanchezd@stanford.eduelse:
6836111Ssteve.reinhardt@amd.com    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
6846109Ssanchezd@stanford.edu    print "Don't know what compiler options to use for your compiler."
6856111Ssteve.reinhardt@amd.com    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
6866109Ssanchezd@stanford.edu    print termcap.Yellow + '       version:' + termcap.Normal,
6876109Ssanchezd@stanford.edu    if not CXX_version:
6886109Ssanchezd@stanford.edu        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
6896109Ssanchezd@stanford.edu               termcap.Normal
6906111Ssteve.reinhardt@amd.com    else:
6916109Ssanchezd@stanford.edu        print CXX_version.replace('\n', '<nl>')
6926109Ssanchezd@stanford.edu    print "       If you're trying to use a compiler other than GCC"
6936109Ssanchezd@stanford.edu    print "       or clang, there appears to be something wrong with your"
6946109Ssanchezd@stanford.edu    print "       environment."
6956109Ssanchezd@stanford.edu    print "       "
6966109Ssanchezd@stanford.edu    print "       If you are trying to use a compiler other than those listed"
6976109Ssanchezd@stanford.edu    print "       above you will need to ease fix SConstruct and "
6986109Ssanchezd@stanford.edu    print "       src/SConscript to support that compiler."
6996109Ssanchezd@stanford.edu    Exit(1)
7006109Ssanchezd@stanford.edu
7016109Ssanchezd@stanford.edu# Set up common yacc/bison flags (needed for Ruby)
7026109Ssanchezd@stanford.edumain['YACCFLAGS'] = '-d'
7036109Ssanchezd@stanford.edumain['YACCHXXFILESUFFIX'] = '.hh'
7046109Ssanchezd@stanford.edu
7056109Ssanchezd@stanford.edu# Do this after we save setting back, or else we'll tack on an
7066111Ssteve.reinhardt@amd.com# extra 'qdo' every time we run scons.
7076110Ssteve.reinhardt@amd.comif main['BATCH']:
7086109Ssanchezd@stanford.edu    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
7096111Ssteve.reinhardt@amd.com    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
7106111Ssteve.reinhardt@amd.com    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
7116109Ssanchezd@stanford.edu    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
7126111Ssteve.reinhardt@amd.com    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
7136109Ssanchezd@stanford.edu
7146110Ssteve.reinhardt@amd.comif sys.platform == 'cygwin':
7156109Ssanchezd@stanford.edu    # cygwin has some header file issues...
7166109Ssanchezd@stanford.edu    main.Append(CCFLAGS=["-Wno-uninitialized"])
7176111Ssteve.reinhardt@amd.com
7186111Ssteve.reinhardt@amd.com# Check for the protobuf compiler
7196109Ssanchezd@stanford.eduprotoc_version = readCommand([main['PROTOC'], '--version'],
7206109Ssanchezd@stanford.edu                             exception='').split()
7216109Ssanchezd@stanford.edu
7226109Ssanchezd@stanford.edu# First two words should be "libprotoc x.y.z"
7236109Ssanchezd@stanford.eduif len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
7246109Ssanchezd@stanford.edu    print termcap.Yellow + termcap.Bold + \
7256109Ssanchezd@stanford.edu        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
7266134Sgblack@eecs.umich.edu        '         Please install protobuf-compiler for tracing support.' + \
7276109Ssanchezd@stanford.edu        termcap.Normal
7286109Ssanchezd@stanford.edu    main['PROTOC'] = False
7296109Ssanchezd@stanford.eduelse:
7306109Ssanchezd@stanford.edu    # Based on the availability of the compress stream wrappers,
7316109Ssanchezd@stanford.edu    # require 2.1.0
7326109Ssanchezd@stanford.edu    min_protoc_version = '2.1.0'
7336109Ssanchezd@stanford.edu    if compareVersions(protoc_version[1], min_protoc_version) < 0:
7346109Ssanchezd@stanford.edu        print termcap.Yellow + termcap.Bold + \
7356109Ssanchezd@stanford.edu            'Warning: protoc version', min_protoc_version, \
7366109Ssanchezd@stanford.edu            'or newer required.\n' + \
7376109Ssanchezd@stanford.edu            '         Installed version:', protoc_version[1], \
7386109Ssanchezd@stanford.edu            termcap.Normal
739        main['PROTOC'] = False
740    else:
741        # Attempt to determine the appropriate include path and
742        # library path using pkg-config, that means we also need to
743        # check for pkg-config. Note that it is possible to use
744        # protobuf without the involvement of pkg-config. Later on we
745        # check go a library config check and at that point the test
746        # will fail if libprotobuf cannot be found.
747        if readCommand(['pkg-config', '--version'], exception=''):
748            try:
749                # Attempt to establish what linking flags to add for protobuf
750                # using pkg-config
751                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
752            except:
753                print termcap.Yellow + termcap.Bold + \
754                    'Warning: pkg-config could not get protobuf flags.' + \
755                    termcap.Normal
756
757# Check for SWIG
758if not main.has_key('SWIG'):
759    print 'Error: SWIG utility not found.'
760    print '       Please install (see http://www.swig.org) and retry.'
761    Exit(1)
762
763# Check for appropriate SWIG version
764swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
765# First 3 words should be "SWIG Version x.y.z"
766if len(swig_version) < 3 or \
767        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
768    print 'Error determining SWIG version.'
769    Exit(1)
770
771min_swig_version = '2.0.4'
772if compareVersions(swig_version[2], min_swig_version) < 0:
773    print 'Error: SWIG version', min_swig_version, 'or newer required.'
774    print '       Installed version:', swig_version[2]
775    Exit(1)
776
777# Check for known incompatibilities. The standard library shipped with
778# gcc >= 4.9 does not play well with swig versions prior to 3.0
779if main['GCC'] and compareVersions(gcc_version, '4.9') >= 0 and \
780        compareVersions(swig_version[2], '3.0') < 0:
781    print termcap.Yellow + termcap.Bold + \
782        'Warning: This combination of gcc and swig have' + \
783        ' known incompatibilities.\n' + \
784        '         If you encounter build problems, please update ' + \
785        'swig to 3.0 or later.' + \
786        termcap.Normal
787
788# Set up SWIG flags & scanner
789swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
790main.Append(SWIGFLAGS=swig_flags)
791
792# Check for 'timeout' from GNU coreutils. If present, regressions will
793# be run with a time limit. We require version 8.13 since we rely on
794# support for the '--foreground' option.
795timeout_lines = readCommand(['timeout', '--version'],
796                            exception='').splitlines()
797# Get the first line and tokenize it
798timeout_version = timeout_lines[0].split() if timeout_lines else []
799main['TIMEOUT'] =  timeout_version and \
800    compareVersions(timeout_version[-1], '8.13') >= 0
801
802# filter out all existing swig scanners, they mess up the dependency
803# stuff for some reason
804scanners = []
805for scanner in main['SCANNERS']:
806    skeys = scanner.skeys
807    if skeys == '.i':
808        continue
809
810    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
811        continue
812
813    scanners.append(scanner)
814
815# add the new swig scanner that we like better
816from SCons.Scanner import ClassicCPP as CPPScanner
817swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
818scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
819
820# replace the scanners list that has what we want
821main['SCANNERS'] = scanners
822
823# Add a custom Check function to test for structure members.
824def CheckMember(context, include, decl, member, include_quotes="<>"):
825    context.Message("Checking for member %s in %s..." %
826                    (member, decl))
827    text = """
828#include %(header)s
829int main(){
830  %(decl)s test;
831  (void)test.%(member)s;
832  return 0;
833};
834""" % { "header" : include_quotes[0] + include + include_quotes[1],
835        "decl" : decl,
836        "member" : member,
837        }
838
839    ret = context.TryCompile(text, extension=".cc")
840    context.Result(ret)
841    return ret
842
843# Platform-specific configuration.  Note again that we assume that all
844# builds under a given build root run on the same host platform.
845conf = Configure(main,
846                 conf_dir = joinpath(build_root, '.scons_config'),
847                 log_file = joinpath(build_root, 'scons_config.log'),
848                 custom_tests = {
849        'CheckMember' : CheckMember,
850        })
851
852# Check if we should compile a 64 bit binary on Mac OS X/Darwin
853try:
854    import platform
855    uname = platform.uname()
856    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
857        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
858            main.Append(CCFLAGS=['-arch', 'x86_64'])
859            main.Append(CFLAGS=['-arch', 'x86_64'])
860            main.Append(LINKFLAGS=['-arch', 'x86_64'])
861            main.Append(ASFLAGS=['-arch', 'x86_64'])
862except:
863    pass
864
865# Recent versions of scons substitute a "Null" object for Configure()
866# when configuration isn't necessary, e.g., if the "--help" option is
867# present.  Unfortuantely this Null object always returns false,
868# breaking all our configuration checks.  We replace it with our own
869# more optimistic null object that returns True instead.
870if not conf:
871    def NullCheck(*args, **kwargs):
872        return True
873
874    class NullConf:
875        def __init__(self, env):
876            self.env = env
877        def Finish(self):
878            return self.env
879        def __getattr__(self, mname):
880            return NullCheck
881
882    conf = NullConf(main)
883
884# Cache build files in the supplied directory.
885if main['M5_BUILD_CACHE']:
886    print 'Using build cache located at', main['M5_BUILD_CACHE']
887    CacheDir(main['M5_BUILD_CACHE'])
888
889if not GetOption('without_python'):
890    # Find Python include and library directories for embedding the
891    # interpreter. We rely on python-config to resolve the appropriate
892    # includes and linker flags. ParseConfig does not seem to understand
893    # the more exotic linker flags such as -Xlinker and -export-dynamic so
894    # we add them explicitly below. If you want to link in an alternate
895    # version of python, see above for instructions on how to invoke
896    # scons with the appropriate PATH set.
897    #
898    # First we check if python2-config exists, else we use python-config
899    python_config = readCommand(['which', 'python2-config'],
900                                exception='').strip()
901    if not os.path.exists(python_config):
902        python_config = readCommand(['which', 'python-config'],
903                                    exception='').strip()
904    py_includes = readCommand([python_config, '--includes'],
905                              exception='').split()
906    # Strip the -I from the include folders before adding them to the
907    # CPPPATH
908    main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
909
910    # Read the linker flags and split them into libraries and other link
911    # flags. The libraries are added later through the call the CheckLib.
912    py_ld_flags = readCommand([python_config, '--ldflags'],
913        exception='').split()
914    py_libs = []
915    for lib in py_ld_flags:
916         if not lib.startswith('-l'):
917             main.Append(LINKFLAGS=[lib])
918         else:
919             lib = lib[2:]
920             if lib not in py_libs:
921                 py_libs.append(lib)
922
923    # verify that this stuff works
924    if not conf.CheckHeader('Python.h', '<>'):
925        print "Error: can't find Python.h header in", py_includes
926        print "Install Python headers (package python-dev on Ubuntu and RedHat)"
927        Exit(1)
928
929    for lib in py_libs:
930        if not conf.CheckLib(lib):
931            print "Error: can't find library %s required by python" % lib
932            Exit(1)
933
934# On Solaris you need to use libsocket for socket ops
935if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
936   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
937       print "Can't find library with socket calls (e.g. accept())"
938       Exit(1)
939
940# Check for zlib.  If the check passes, libz will be automatically
941# added to the LIBS environment variable.
942if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
943    print 'Error: did not find needed zlib compression library '\
944          'and/or zlib.h header file.'
945    print '       Please install zlib and try again.'
946    Exit(1)
947
948# If we have the protobuf compiler, also make sure we have the
949# development libraries. If the check passes, libprotobuf will be
950# automatically added to the LIBS environment variable. After
951# this, we can use the HAVE_PROTOBUF flag to determine if we have
952# got both protoc and libprotobuf available.
953main['HAVE_PROTOBUF'] = main['PROTOC'] and \
954    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
955                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
956
957# If we have the compiler but not the library, print another warning.
958if main['PROTOC'] and not main['HAVE_PROTOBUF']:
959    print termcap.Yellow + termcap.Bold + \
960        'Warning: did not find protocol buffer library and/or headers.\n' + \
961    '       Please install libprotobuf-dev for tracing support.' + \
962    termcap.Normal
963
964# Check for librt.
965have_posix_clock = \
966    conf.CheckLibWithHeader(None, 'time.h', 'C',
967                            'clock_nanosleep(0,0,NULL,NULL);') or \
968    conf.CheckLibWithHeader('rt', 'time.h', 'C',
969                            'clock_nanosleep(0,0,NULL,NULL);')
970
971have_posix_timers = \
972    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
973                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
974
975if not GetOption('without_tcmalloc'):
976    if conf.CheckLib('tcmalloc'):
977        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
978    elif conf.CheckLib('tcmalloc_minimal'):
979        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
980    else:
981        print termcap.Yellow + termcap.Bold + \
982              "You can get a 12% performance improvement by "\
983              "installing tcmalloc (libgoogle-perftools-dev package "\
984              "on Ubuntu or RedHat)." + termcap.Normal
985
986
987# Detect back trace implementations. The last implementation in the
988# list will be used by default.
989backtrace_impls = [ "none" ]
990
991if conf.CheckLibWithHeader(None, 'execinfo.h', 'C',
992                           'backtrace_symbols_fd((void*)0, 0, 0);'):
993    backtrace_impls.append("glibc")
994
995if backtrace_impls[-1] == "none":
996    default_backtrace_impl = "none"
997    print termcap.Yellow + termcap.Bold + \
998        "No suitable back trace implementation found." + \
999        termcap.Normal
1000
1001if not have_posix_clock:
1002    print "Can't find library for POSIX clocks."
1003
1004# Check for <fenv.h> (C99 FP environment control)
1005have_fenv = conf.CheckHeader('fenv.h', '<>')
1006if not have_fenv:
1007    print "Warning: Header file <fenv.h> not found."
1008    print "         This host has no IEEE FP rounding mode control."
1009
1010# Check if we should enable KVM-based hardware virtualization. The API
1011# we rely on exists since version 2.6.36 of the kernel, but somehow
1012# the KVM_API_VERSION does not reflect the change. We test for one of
1013# the types as a fall back.
1014have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
1015if not have_kvm:
1016    print "Info: Compatible header file <linux/kvm.h> not found, " \
1017        "disabling KVM support."
1018
1019# x86 needs support for xsave. We test for the structure here since we
1020# won't be able to run new tests by the time we know which ISA we're
1021# targeting.
1022have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
1023                                    '#include <linux/kvm.h>') != 0
1024
1025# Check if the requested target ISA is compatible with the host
1026def is_isa_kvm_compatible(isa):
1027    try:
1028        import platform
1029        host_isa = platform.machine()
1030    except:
1031        print "Warning: Failed to determine host ISA."
1032        return False
1033
1034    if not have_posix_timers:
1035        print "Warning: Can not enable KVM, host seems to lack support " \
1036            "for POSIX timers"
1037        return False
1038
1039    if isa == "arm":
1040        return host_isa in ( "armv7l", "aarch64" )
1041    elif isa == "x86":
1042        if host_isa != "x86_64":
1043            return False
1044
1045        if not have_kvm_xsave:
1046            print "KVM on x86 requires xsave support in kernel headers."
1047            return False
1048
1049        return True
1050    else:
1051        return False
1052
1053
1054# Check if the exclude_host attribute is available. We want this to
1055# get accurate instruction counts in KVM.
1056main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1057    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1058
1059
1060######################################################################
1061#
1062# Finish the configuration
1063#
1064main = conf.Finish()
1065
1066######################################################################
1067#
1068# Collect all non-global variables
1069#
1070
1071# Define the universe of supported ISAs
1072all_isa_list = [ ]
1073Export('all_isa_list')
1074
1075class CpuModel(object):
1076    '''The CpuModel class encapsulates everything the ISA parser needs to
1077    know about a particular CPU model.'''
1078
1079    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1080    dict = {}
1081
1082    # Constructor.  Automatically adds models to CpuModel.dict.
1083    def __init__(self, name, default=False):
1084        self.name = name           # name of model
1085
1086        # This cpu is enabled by default
1087        self.default = default
1088
1089        # Add self to dict
1090        if name in CpuModel.dict:
1091            raise AttributeError, "CpuModel '%s' already registered" % name
1092        CpuModel.dict[name] = self
1093
1094Export('CpuModel')
1095
1096# Sticky variables get saved in the variables file so they persist from
1097# one invocation to the next (unless overridden, in which case the new
1098# value becomes sticky).
1099sticky_vars = Variables(args=ARGUMENTS)
1100Export('sticky_vars')
1101
1102# Sticky variables that should be exported
1103export_vars = []
1104Export('export_vars')
1105
1106# For Ruby
1107all_protocols = []
1108Export('all_protocols')
1109protocol_dirs = []
1110Export('protocol_dirs')
1111slicc_includes = []
1112Export('slicc_includes')
1113
1114# Walk the tree and execute all SConsopts scripts that wil add to the
1115# above variables
1116if GetOption('verbose'):
1117    print "Reading SConsopts"
1118for bdir in [ base_dir ] + extras_dir_list:
1119    if not isdir(bdir):
1120        print "Error: directory '%s' does not exist" % bdir
1121        Exit(1)
1122    for root, dirs, files in os.walk(bdir):
1123        if 'SConsopts' in files:
1124            if GetOption('verbose'):
1125                print "Reading", joinpath(root, 'SConsopts')
1126            SConscript(joinpath(root, 'SConsopts'))
1127
1128all_isa_list.sort()
1129
1130sticky_vars.AddVariables(
1131    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1132    ListVariable('CPU_MODELS', 'CPU models',
1133                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1134                 sorted(CpuModel.dict.keys())),
1135    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1136                 False),
1137    BoolVariable('SS_COMPATIBLE_FP',
1138                 'Make floating-point results compatible with SimpleScalar',
1139                 False),
1140    BoolVariable('USE_SSE2',
1141                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1142                 False),
1143    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1144    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1145    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1146    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1147    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1148                  all_protocols),
1149    EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1150                 backtrace_impls[-1], backtrace_impls)
1151    )
1152
1153# These variables get exported to #defines in config/*.hh (see src/SConscript).
1154export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
1155                'USE_POSIX_CLOCK', 'USE_KVM', 'PROTOCOL', 'HAVE_PROTOBUF',
1156                'HAVE_PERF_ATTR_EXCLUDE_HOST']
1157
1158###################################################
1159#
1160# Define a SCons builder for configuration flag headers.
1161#
1162###################################################
1163
1164# This function generates a config header file that #defines the
1165# variable symbol to the current variable setting (0 or 1).  The source
1166# operands are the name of the variable and a Value node containing the
1167# value of the variable.
1168def build_config_file(target, source, env):
1169    (variable, value) = [s.get_contents() for s in source]
1170    f = file(str(target[0]), 'w')
1171    print >> f, '#define', variable, value
1172    f.close()
1173    return None
1174
1175# Combine the two functions into a scons Action object.
1176config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1177
1178# The emitter munges the source & target node lists to reflect what
1179# we're really doing.
1180def config_emitter(target, source, env):
1181    # extract variable name from Builder arg
1182    variable = str(target[0])
1183    # True target is config header file
1184    target = joinpath('config', variable.lower() + '.hh')
1185    val = env[variable]
1186    if isinstance(val, bool):
1187        # Force value to 0/1
1188        val = int(val)
1189    elif isinstance(val, str):
1190        val = '"' + val + '"'
1191
1192    # Sources are variable name & value (packaged in SCons Value nodes)
1193    return ([target], [Value(variable), Value(val)])
1194
1195config_builder = Builder(emitter = config_emitter, action = config_action)
1196
1197main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1198
1199# libelf build is shared across all configs in the build root.
1200main.SConscript('ext/libelf/SConscript',
1201                variant_dir = joinpath(build_root, 'libelf'))
1202
1203# gzstream build is shared across all configs in the build root.
1204main.SConscript('ext/gzstream/SConscript',
1205                variant_dir = joinpath(build_root, 'gzstream'))
1206
1207# libfdt build is shared across all configs in the build root.
1208main.SConscript('ext/libfdt/SConscript',
1209                variant_dir = joinpath(build_root, 'libfdt'))
1210
1211# fputils build is shared across all configs in the build root.
1212main.SConscript('ext/fputils/SConscript',
1213                variant_dir = joinpath(build_root, 'fputils'))
1214
1215# DRAMSim2 build is shared across all configs in the build root.
1216main.SConscript('ext/dramsim2/SConscript',
1217                variant_dir = joinpath(build_root, 'dramsim2'))
1218
1219# DRAMPower build is shared across all configs in the build root.
1220main.SConscript('ext/drampower/SConscript',
1221                variant_dir = joinpath(build_root, 'drampower'))
1222
1223# nomali build is shared across all configs in the build root.
1224main.SConscript('ext/nomali/SConscript',
1225                variant_dir = joinpath(build_root, 'nomali'))
1226
1227###################################################
1228#
1229# This function is used to set up a directory with switching headers
1230#
1231###################################################
1232
1233main['ALL_ISA_LIST'] = all_isa_list
1234all_isa_deps = {}
1235def make_switching_dir(dname, switch_headers, env):
1236    # Generate the header.  target[0] is the full path of the output
1237    # header to generate.  'source' is a dummy variable, since we get the
1238    # list of ISAs from env['ALL_ISA_LIST'].
1239    def gen_switch_hdr(target, source, env):
1240        fname = str(target[0])
1241        isa = env['TARGET_ISA'].lower()
1242        try:
1243            f = open(fname, 'w')
1244            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1245            f.close()
1246        except IOError:
1247            print "Failed to create %s" % fname
1248            raise
1249
1250    # Build SCons Action object. 'varlist' specifies env vars that this
1251    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1252    # should get re-executed.
1253    switch_hdr_action = MakeAction(gen_switch_hdr,
1254                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1255
1256    # Instantiate actions for each header
1257    for hdr in switch_headers:
1258        env.Command(hdr, [], switch_hdr_action)
1259
1260    isa_target = Dir('.').up().name.lower().replace('_', '-')
1261    env['PHONY_BASE'] = '#'+isa_target
1262    all_isa_deps[isa_target] = None
1263
1264Export('make_switching_dir')
1265
1266# all-isas -> all-deps -> all-environs -> all_targets
1267main.Alias('#all-isas', [])
1268main.Alias('#all-deps', '#all-isas')
1269
1270# Dummy target to ensure all environments are created before telling
1271# SCons what to actually make (the command line arguments).  We attach
1272# them to the dependence graph after the environments are complete.
1273ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1274def environsComplete(target, source, env):
1275    for t in ORIG_BUILD_TARGETS:
1276        main.Depends('#all-targets', t)
1277
1278# Each build/* switching_dir attaches its *-environs target to #all-environs.
1279main.Append(BUILDERS = {'CompleteEnvirons' :
1280                        Builder(action=MakeAction(environsComplete, None))})
1281main.CompleteEnvirons('#all-environs', [])
1282
1283def doNothing(**ignored): pass
1284main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1285
1286# The final target to which all the original targets ultimately get attached.
1287main.Dummy('#all-targets', '#all-environs')
1288BUILD_TARGETS[:] = ['#all-targets']
1289
1290###################################################
1291#
1292# Define build environments for selected configurations.
1293#
1294###################################################
1295
1296for variant_path in variant_paths:
1297    if not GetOption('silent'):
1298        print "Building in", variant_path
1299
1300    # Make a copy of the build-root environment to use for this config.
1301    env = main.Clone()
1302    env['BUILDDIR'] = variant_path
1303
1304    # variant_dir is the tail component of build path, and is used to
1305    # determine the build parameters (e.g., 'ALPHA_SE')
1306    (build_root, variant_dir) = splitpath(variant_path)
1307
1308    # Set env variables according to the build directory config.
1309    sticky_vars.files = []
1310    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1311    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1312    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1313    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1314    if isfile(current_vars_file):
1315        sticky_vars.files.append(current_vars_file)
1316        if not GetOption('silent'):
1317            print "Using saved variables file %s" % current_vars_file
1318    else:
1319        # Build dir-specific variables file doesn't exist.
1320
1321        # Make sure the directory is there so we can create it later
1322        opt_dir = dirname(current_vars_file)
1323        if not isdir(opt_dir):
1324            mkdir(opt_dir)
1325
1326        # Get default build variables from source tree.  Variables are
1327        # normally determined by name of $VARIANT_DIR, but can be
1328        # overridden by '--default=' arg on command line.
1329        default = GetOption('default')
1330        opts_dir = joinpath(main.root.abspath, 'build_opts')
1331        if default:
1332            default_vars_files = [joinpath(build_root, 'variables', default),
1333                                  joinpath(opts_dir, default)]
1334        else:
1335            default_vars_files = [joinpath(opts_dir, variant_dir)]
1336        existing_files = filter(isfile, default_vars_files)
1337        if existing_files:
1338            default_vars_file = existing_files[0]
1339            sticky_vars.files.append(default_vars_file)
1340            print "Variables file %s not found,\n  using defaults in %s" \
1341                  % (current_vars_file, default_vars_file)
1342        else:
1343            print "Error: cannot find variables file %s or " \
1344                  "default file(s) %s" \
1345                  % (current_vars_file, ' or '.join(default_vars_files))
1346            Exit(1)
1347
1348    # Apply current variable settings to env
1349    sticky_vars.Update(env)
1350
1351    help_texts["local_vars"] += \
1352        "Build variables for %s:\n" % variant_dir \
1353                 + sticky_vars.GenerateHelpText(env)
1354
1355    # Process variable settings.
1356
1357    if not have_fenv and env['USE_FENV']:
1358        print "Warning: <fenv.h> not available; " \
1359              "forcing USE_FENV to False in", variant_dir + "."
1360        env['USE_FENV'] = False
1361
1362    if not env['USE_FENV']:
1363        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1364        print "         FP results may deviate slightly from other platforms."
1365
1366    if env['EFENCE']:
1367        env.Append(LIBS=['efence'])
1368
1369    if env['USE_KVM']:
1370        if not have_kvm:
1371            print "Warning: Can not enable KVM, host seems to lack KVM support"
1372            env['USE_KVM'] = False
1373        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1374            print "Info: KVM support disabled due to unsupported host and " \
1375                "target ISA combination"
1376            env['USE_KVM'] = False
1377
1378    # Warn about missing optional functionality
1379    if env['USE_KVM']:
1380        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1381            print "Warning: perf_event headers lack support for the " \
1382                "exclude_host attribute. KVM instruction counts will " \
1383                "be inaccurate."
1384
1385    # Save sticky variable settings back to current variables file
1386    sticky_vars.Save(current_vars_file, env)
1387
1388    if env['USE_SSE2']:
1389        env.Append(CCFLAGS=['-msse2'])
1390
1391    # The src/SConscript file sets up the build rules in 'env' according
1392    # to the configured variables.  It returns a list of environments,
1393    # one for each variant build (debug, opt, etc.)
1394    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1395
1396def pairwise(iterable):
1397    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1398    a, b = itertools.tee(iterable)
1399    b.next()
1400    return itertools.izip(a, b)
1401
1402# Create false dependencies so SCons will parse ISAs, establish
1403# dependencies, and setup the build Environments serially. Either
1404# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1405# greater than 1. It appears to be standard race condition stuff; it
1406# doesn't always fail, but usually, and the behaviors are different.
1407# Every time I tried to remove this, builds would fail in some
1408# creative new way. So, don't do that. You'll want to, though, because
1409# tests/SConscript takes a long time to make its Environments.
1410for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1411    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1412    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1413
1414# base help text
1415Help('''
1416Usage: scons [scons options] [build variables] [target(s)]
1417
1418Extra scons options:
1419%(options)s
1420
1421Global build variables:
1422%(global_vars)s
1423
1424%(local_vars)s
1425''' % help_texts)
1426