SConstruct revision 10671:d59e40b074c6
1# -*- mode:python -*-
2
3# Copyright (c) 2013 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# Check for recent-enough Python and SCons versions.
82try:
83    # Really old versions of scons only take two options for the
84    # function, so check once without the revision and once with the
85    # revision, the first instance will fail for stuff other than
86    # 0.98, and the second will fail for 0.98.0
87    EnsureSConsVersion(0, 98)
88    EnsureSConsVersion(0, 98, 1)
89except SystemExit, e:
90    print """
91For more details, see:
92    http://gem5.org/Dependencies
93"""
94    raise
95
96# We ensure the python version early because because python-config
97# requires python 2.5
98try:
99    EnsurePythonVersion(2, 5)
100except SystemExit, e:
101    print """
102You can use a non-default installation of the Python interpreter by
103rearranging your PATH so that scons finds the non-default 'python' and
104'python-config' first.
105
106For more details, see:
107    http://gem5.org/wiki/index.php/Using_a_non-default_Python_installation
108"""
109    raise
110
111# Global Python includes
112import itertools
113import os
114import re
115import subprocess
116import sys
117
118from os import mkdir, environ
119from os.path import abspath, basename, dirname, expanduser, normpath
120from os.path import exists,  isdir, isfile
121from os.path import join as joinpath, split as splitpath
122
123# SCons includes
124import SCons
125import SCons.Node
126
127extra_python_paths = [
128    Dir('src/python').srcnode().abspath, # gem5 includes
129    Dir('ext/ply').srcnode().abspath, # ply is used by several files
130    ]
131
132sys.path[1:1] = extra_python_paths
133
134from m5.util import compareVersions, readCommand
135from m5.util.terminal import get_termcap
136
137help_texts = {
138    "options" : "",
139    "global_vars" : "",
140    "local_vars" : ""
141}
142
143Export("help_texts")
144
145
146# There's a bug in scons in that (1) by default, the help texts from
147# AddOption() are supposed to be displayed when you type 'scons -h'
148# and (2) you can override the help displayed by 'scons -h' using the
149# Help() function, but these two features are incompatible: once
150# you've overridden the help text using Help(), there's no way to get
151# at the help texts from AddOptions.  See:
152#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
153#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
154# This hack lets us extract the help text from AddOptions and
155# re-inject it via Help().  Ideally someday this bug will be fixed and
156# we can just use AddOption directly.
157def AddLocalOption(*args, **kwargs):
158    col_width = 30
159
160    help = "  " + ", ".join(args)
161    if "help" in kwargs:
162        length = len(help)
163        if length >= col_width:
164            help += "\n" + " " * col_width
165        else:
166            help += " " * (col_width - length)
167        help += kwargs["help"]
168    help_texts["options"] += help + "\n"
169
170    AddOption(*args, **kwargs)
171
172AddLocalOption('--colors', dest='use_colors', action='store_true',
173               help="Add color to abbreviated scons output")
174AddLocalOption('--no-colors', dest='use_colors', action='store_false',
175               help="Don't add color to abbreviated scons output")
176AddLocalOption('--with-cxx-config', dest='with_cxx_config',
177               action='store_true',
178               help="Build with support for C++-based configuration")
179AddLocalOption('--default', dest='default', type='string', action='store',
180               help='Override which build_opts file to use for defaults')
181AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
182               help='Disable style checking hooks')
183AddLocalOption('--no-lto', dest='no_lto', action='store_true',
184               help='Disable Link-Time Optimization for fast')
185AddLocalOption('--update-ref', dest='update_ref', action='store_true',
186               help='Update test reference outputs')
187AddLocalOption('--verbose', dest='verbose', action='store_true',
188               help='Print full tool command lines')
189AddLocalOption('--without-python', dest='without_python',
190               action='store_true',
191               help='Build without Python configuration support')
192AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
193               action='store_true',
194               help='Disable linking against tcmalloc')
195AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
196               help='Build with Undefined Behavior Sanitizer if available')
197
198termcap = get_termcap(GetOption('use_colors'))
199
200########################################################################
201#
202# Set up the main build environment.
203#
204########################################################################
205
206# export TERM so that clang reports errors in color
207use_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH',
208                 'LIBRARY_PATH', 'PATH', 'PKG_CONFIG_PATH', 'PROTOC',
209                 'PYTHONPATH', 'RANLIB', 'SWIG', 'TERM' ])
210
211use_prefixes = [
212    "M5",           # M5 configuration (e.g., path to kernels)
213    "DISTCC_",      # distcc (distributed compiler wrapper) configuration
214    "CCACHE_",      # ccache (caching compiler wrapper) configuration
215    "CCC_",         # clang static analyzer configuration
216    ]
217
218use_env = {}
219for key,val in sorted(os.environ.iteritems()):
220    if key in use_vars or \
221            any([key.startswith(prefix) for prefix in use_prefixes]):
222        use_env[key] = val
223
224# Tell scons to avoid implicit command dependencies to avoid issues
225# with the param wrappes being compiled twice (see
226# http://scons.tigris.org/issues/show_bug.cgi?id=2811)
227main = Environment(ENV=use_env, IMPLICIT_COMMAND_DEPENDENCIES=0)
228main.Decider('MD5-timestamp')
229main.root = Dir(".")         # The current directory (where this file lives).
230main.srcdir = Dir("src")     # The source directory
231
232main_dict_keys = main.Dictionary().keys()
233
234# Check that we have a C/C++ compiler
235if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
236    print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
237    Exit(1)
238
239# Check that swig is present
240if not 'SWIG' in main_dict_keys:
241    print "swig is not installed (package swig on Ubuntu and RedHat)"
242    Exit(1)
243
244# add useful python code PYTHONPATH so it can be used by subprocesses
245# as well
246main.AppendENVPath('PYTHONPATH', extra_python_paths)
247
248########################################################################
249#
250# Mercurial Stuff.
251#
252# If the gem5 directory is a mercurial repository, we should do some
253# extra things.
254#
255########################################################################
256
257hgdir = main.root.Dir(".hg")
258
259mercurial_style_message = """
260You're missing the gem5 style hook, which automatically checks your code
261against the gem5 style rules on hg commit and qrefresh commands.  This
262script will now install the hook in your .hg/hgrc file.
263Press enter to continue, or ctrl-c to abort: """
264
265mercurial_style_hook = """
266# The following lines were automatically added by gem5/SConstruct
267# to provide the gem5 style-checking hooks
268[extensions]
269style = %s/util/style.py
270
271[hooks]
272pretxncommit.style = python:style.check_style
273pre-qrefresh.style = python:style.check_style
274# End of SConstruct additions
275
276""" % (main.root.abspath)
277
278mercurial_lib_not_found = """
279Mercurial libraries cannot be found, ignoring style hook.  If
280you are a gem5 developer, please fix this and run the style
281hook. It is important.
282"""
283
284# Check for style hook and prompt for installation if it's not there.
285# Skip this if --ignore-style was specified, there's no .hg dir to
286# install a hook in, or there's no interactive terminal to prompt.
287if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
288    style_hook = True
289    try:
290        from mercurial import ui
291        ui = ui.ui()
292        ui.readconfig(hgdir.File('hgrc').abspath)
293        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
294                     ui.config('hooks', 'pre-qrefresh.style', None)
295    except ImportError:
296        print mercurial_lib_not_found
297
298    if not style_hook:
299        print mercurial_style_message,
300        # continue unless user does ctrl-c/ctrl-d etc.
301        try:
302            raw_input()
303        except:
304            print "Input exception, exiting scons.\n"
305            sys.exit(1)
306        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
307        print "Adding style hook to", hgrc_path, "\n"
308        try:
309            hgrc = open(hgrc_path, 'a')
310            hgrc.write(mercurial_style_hook)
311            hgrc.close()
312        except:
313            print "Error updating", hgrc_path
314            sys.exit(1)
315
316
317###################################################
318#
319# Figure out which configurations to set up based on the path(s) of
320# the target(s).
321#
322###################################################
323
324# Find default configuration & binary.
325Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
326
327# helper function: find last occurrence of element in list
328def rfind(l, elt, offs = -1):
329    for i in range(len(l)+offs, 0, -1):
330        if l[i] == elt:
331            return i
332    raise ValueError, "element not found"
333
334# Take a list of paths (or SCons Nodes) and return a list with all
335# paths made absolute and ~-expanded.  Paths will be interpreted
336# relative to the launch directory unless a different root is provided
337def makePathListAbsolute(path_list, root=GetLaunchDir()):
338    return [abspath(joinpath(root, expanduser(str(p))))
339            for p in path_list]
340
341# Each target must have 'build' in the interior of the path; the
342# directory below this will determine the build parameters.  For
343# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
344# recognize that ALPHA_SE specifies the configuration because it
345# follow 'build' in the build path.
346
347# The funky assignment to "[:]" is needed to replace the list contents
348# in place rather than reassign the symbol to a new list, which
349# doesn't work (obviously!).
350BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
351
352# Generate a list of the unique build roots and configs that the
353# collected targets reference.
354variant_paths = []
355build_root = None
356for t in BUILD_TARGETS:
357    path_dirs = t.split('/')
358    try:
359        build_top = rfind(path_dirs, 'build', -2)
360    except:
361        print "Error: no non-leaf 'build' dir found on target path", t
362        Exit(1)
363    this_build_root = joinpath('/',*path_dirs[:build_top+1])
364    if not build_root:
365        build_root = this_build_root
366    else:
367        if this_build_root != build_root:
368            print "Error: build targets not under same build root\n"\
369                  "  %s\n  %s" % (build_root, this_build_root)
370            Exit(1)
371    variant_path = joinpath('/',*path_dirs[:build_top+2])
372    if variant_path not in variant_paths:
373        variant_paths.append(variant_path)
374
375# Make sure build_root exists (might not if this is the first build there)
376if not isdir(build_root):
377    mkdir(build_root)
378main['BUILDROOT'] = build_root
379
380Export('main')
381
382main.SConsignFile(joinpath(build_root, "sconsign"))
383
384# Default duplicate option is to use hard links, but this messes up
385# when you use emacs to edit a file in the target dir, as emacs moves
386# file to file~ then copies to file, breaking the link.  Symbolic
387# (soft) links work better.
388main.SetOption('duplicate', 'soft-copy')
389
390#
391# Set up global sticky variables... these are common to an entire build
392# tree (not specific to a particular build like ALPHA_SE)
393#
394
395global_vars_file = joinpath(build_root, 'variables.global')
396
397global_vars = Variables(global_vars_file, args=ARGUMENTS)
398
399global_vars.AddVariables(
400    ('CC', 'C compiler', environ.get('CC', main['CC'])),
401    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
402    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
403    ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
404    ('BATCH', 'Use batch pool for build and tests', False),
405    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
406    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
407    ('EXTRAS', 'Add extra directories to the compilation', '')
408    )
409
410# Update main environment with values from ARGUMENTS & global_vars_file
411global_vars.Update(main)
412help_texts["global_vars"] += global_vars.GenerateHelpText(main)
413
414# Save sticky variable settings back to current variables file
415global_vars.Save(global_vars_file, main)
416
417# Parse EXTRAS variable to build list of all directories where we're
418# look for sources etc.  This list is exported as extras_dir_list.
419base_dir = main.srcdir.abspath
420if main['EXTRAS']:
421    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
422else:
423    extras_dir_list = []
424
425Export('base_dir')
426Export('extras_dir_list')
427
428# the ext directory should be on the #includes path
429main.Append(CPPPATH=[Dir('ext')])
430
431def strip_build_path(path, env):
432    path = str(path)
433    variant_base = env['BUILDROOT'] + os.path.sep
434    if path.startswith(variant_base):
435        path = path[len(variant_base):]
436    elif path.startswith('build/'):
437        path = path[6:]
438    return path
439
440# Generate a string of the form:
441#   common/path/prefix/src1, src2 -> tgt1, tgt2
442# to print while building.
443class Transform(object):
444    # all specific color settings should be here and nowhere else
445    tool_color = termcap.Normal
446    pfx_color = termcap.Yellow
447    srcs_color = termcap.Yellow + termcap.Bold
448    arrow_color = termcap.Blue + termcap.Bold
449    tgts_color = termcap.Yellow + termcap.Bold
450
451    def __init__(self, tool, max_sources=99):
452        self.format = self.tool_color + (" [%8s] " % tool) \
453                      + self.pfx_color + "%s" \
454                      + self.srcs_color + "%s" \
455                      + self.arrow_color + " -> " \
456                      + self.tgts_color + "%s" \
457                      + termcap.Normal
458        self.max_sources = max_sources
459
460    def __call__(self, target, source, env, for_signature=None):
461        # truncate source list according to max_sources param
462        source = source[0:self.max_sources]
463        def strip(f):
464            return strip_build_path(str(f), env)
465        if len(source) > 0:
466            srcs = map(strip, source)
467        else:
468            srcs = ['']
469        tgts = map(strip, target)
470        # surprisingly, os.path.commonprefix is a dumb char-by-char string
471        # operation that has nothing to do with paths.
472        com_pfx = os.path.commonprefix(srcs + tgts)
473        com_pfx_len = len(com_pfx)
474        if com_pfx:
475            # do some cleanup and sanity checking on common prefix
476            if com_pfx[-1] == ".":
477                # prefix matches all but file extension: ok
478                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
479                com_pfx = com_pfx[0:-1]
480            elif com_pfx[-1] == "/":
481                # common prefix is directory path: OK
482                pass
483            else:
484                src0_len = len(srcs[0])
485                tgt0_len = len(tgts[0])
486                if src0_len == com_pfx_len:
487                    # source is a substring of target, OK
488                    pass
489                elif tgt0_len == com_pfx_len:
490                    # target is a substring of source, need to back up to
491                    # avoid empty string on RHS of arrow
492                    sep_idx = com_pfx.rfind(".")
493                    if sep_idx != -1:
494                        com_pfx = com_pfx[0:sep_idx]
495                    else:
496                        com_pfx = ''
497                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
498                    # still splitting at file extension: ok
499                    pass
500                else:
501                    # probably a fluke; ignore it
502                    com_pfx = ''
503        # recalculate length in case com_pfx was modified
504        com_pfx_len = len(com_pfx)
505        def fmt(files):
506            f = map(lambda s: s[com_pfx_len:], files)
507            return ', '.join(f)
508        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
509
510Export('Transform')
511
512# enable the regression script to use the termcap
513main['TERMCAP'] = termcap
514
515if GetOption('verbose'):
516    def MakeAction(action, string, *args, **kwargs):
517        return Action(action, *args, **kwargs)
518else:
519    MakeAction = Action
520    main['CCCOMSTR']        = Transform("CC")
521    main['CXXCOMSTR']       = Transform("CXX")
522    main['ASCOMSTR']        = Transform("AS")
523    main['SWIGCOMSTR']      = Transform("SWIG")
524    main['ARCOMSTR']        = Transform("AR", 0)
525    main['LINKCOMSTR']      = Transform("LINK", 0)
526    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
527    main['M4COMSTR']        = Transform("M4")
528    main['SHCCCOMSTR']      = Transform("SHCC")
529    main['SHCXXCOMSTR']     = Transform("SHCXX")
530Export('MakeAction')
531
532# Initialize the Link-Time Optimization (LTO) flags
533main['LTO_CCFLAGS'] = []
534main['LTO_LDFLAGS'] = []
535
536# According to the readme, tcmalloc works best if the compiler doesn't
537# assume that we're using the builtin malloc and friends. These flags
538# are compiler-specific, so we need to set them after we detect which
539# compiler we're using.
540main['TCMALLOC_CCFLAGS'] = []
541
542CXX_version = readCommand([main['CXX'],'--version'], exception=False)
543CXX_V = readCommand([main['CXX'],'-V'], exception=False)
544
545main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
546main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
547if main['GCC'] + main['CLANG'] > 1:
548    print 'Error: How can we have two at the same time?'
549    Exit(1)
550
551# Set up default C++ compiler flags
552if main['GCC'] or main['CLANG']:
553    # As gcc and clang share many flags, do the common parts here
554    main.Append(CCFLAGS=['-pipe'])
555    main.Append(CCFLAGS=['-fno-strict-aliasing'])
556    # Enable -Wall and then disable the few warnings that we
557    # consistently violate
558    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
559    # We always compile using C++11, but only gcc >= 4.7 and clang 3.1
560    # actually use that name, so we stick with c++0x
561    main.Append(CXXFLAGS=['-std=c++0x'])
562    # Add selected sanity checks from -Wextra
563    main.Append(CXXFLAGS=['-Wmissing-field-initializers',
564                          '-Woverloaded-virtual'])
565else:
566    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
567    print "Don't know what compiler options to use for your compiler."
568    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
569    print termcap.Yellow + '       version:' + termcap.Normal,
570    if not CXX_version:
571        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
572               termcap.Normal
573    else:
574        print CXX_version.replace('\n', '<nl>')
575    print "       If you're trying to use a compiler other than GCC"
576    print "       or clang, there appears to be something wrong with your"
577    print "       environment."
578    print "       "
579    print "       If you are trying to use a compiler other than those listed"
580    print "       above you will need to ease fix SConstruct and "
581    print "       src/SConscript to support that compiler."
582    Exit(1)
583
584if main['GCC']:
585    # Check for a supported version of gcc. >= 4.6 is chosen for its
586    # level of c++11 support. See
587    # http://gcc.gnu.org/projects/cxx0x.html for details. 4.6 is also
588    # the first version with proper LTO support.
589    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
590    if compareVersions(gcc_version, "4.6") < 0:
591        print 'Error: gcc version 4.6 or newer required.'
592        print '       Installed version:', gcc_version
593        Exit(1)
594
595    main['GCC_VERSION'] = gcc_version
596
597    # gcc from version 4.8 and above generates "rep; ret" instructions
598    # to avoid performance penalties on certain AMD chips. Older
599    # assemblers detect this as an error, "Error: expecting string
600    # instruction after `rep'"
601    if compareVersions(gcc_version, "4.8") > 0:
602        as_version = readCommand([main['AS'], '-v', '/dev/null'],
603                                 exception=False).split()
604
605        if not as_version or compareVersions(as_version[-1], "2.23") < 0:
606            print termcap.Yellow + termcap.Bold + \
607                'Warning: This combination of gcc and binutils have' + \
608                ' known incompatibilities.\n' + \
609                '         If you encounter build problems, please update ' + \
610                'binutils to 2.23.' + \
611                termcap.Normal
612
613    # Make sure we warn if the user has requested to compile with the
614    # Undefined Benahvior Sanitizer and this version of gcc does not
615    # support it.
616    if GetOption('with_ubsan') and \
617            compareVersions(gcc_version, '4.9') < 0:
618        print termcap.Yellow + termcap.Bold + \
619            'Warning: UBSan is only supported using gcc 4.9 and later.' + \
620            termcap.Normal
621
622    # Add the appropriate Link-Time Optimization (LTO) flags
623    # unless LTO is explicitly turned off. Note that these flags
624    # are only used by the fast target.
625    if not GetOption('no_lto'):
626        # Pass the LTO flag when compiling to produce GIMPLE
627        # output, we merely create the flags here and only append
628        # them later
629        main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
630
631        # Use the same amount of jobs for LTO as we are running
632        # scons with
633        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
634
635    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
636                                  '-fno-builtin-realloc', '-fno-builtin-free'])
637
638elif main['CLANG']:
639    # Check for a supported version of clang, >= 3.0 is needed to
640    # support similar features as gcc 4.6. See
641    # http://clang.llvm.org/cxx_status.html for details
642    clang_version_re = re.compile(".* version (\d+\.\d+)")
643    clang_version_match = clang_version_re.search(CXX_version)
644    if (clang_version_match):
645        clang_version = clang_version_match.groups()[0]
646        if compareVersions(clang_version, "3.0") < 0:
647            print 'Error: clang version 3.0 or newer required.'
648            print '       Installed version:', clang_version
649            Exit(1)
650    else:
651        print 'Error: Unable to determine clang version.'
652        Exit(1)
653
654    # clang has a few additional warnings that we disable,
655    # tautological comparisons are allowed due to unsigned integers
656    # being compared to constants that happen to be 0, and extraneous
657    # parantheses are allowed due to Ruby's printing of the AST,
658    # finally self assignments are allowed as the generated CPU code
659    # is relying on this
660    main.Append(CCFLAGS=['-Wno-tautological-compare',
661                         '-Wno-parentheses',
662                         '-Wno-self-assign',
663                         # Some versions of libstdc++ (4.8?) seem to
664                         # use struct hash and class hash
665                         # interchangeably.
666                         '-Wno-mismatched-tags',
667                         ])
668
669    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
670
671    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
672    # opposed to libstdc++, as the later is dated.
673    if sys.platform == "darwin":
674        main.Append(CXXFLAGS=['-stdlib=libc++'])
675        main.Append(LIBS=['c++'])
676
677else:
678    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
679    print "Don't know what compiler options to use for your compiler."
680    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
681    print termcap.Yellow + '       version:' + termcap.Normal,
682    if not CXX_version:
683        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
684               termcap.Normal
685    else:
686        print CXX_version.replace('\n', '<nl>')
687    print "       If you're trying to use a compiler other than GCC"
688    print "       or clang, there appears to be something wrong with your"
689    print "       environment."
690    print "       "
691    print "       If you are trying to use a compiler other than those listed"
692    print "       above you will need to ease fix SConstruct and "
693    print "       src/SConscript to support that compiler."
694    Exit(1)
695
696# Set up common yacc/bison flags (needed for Ruby)
697main['YACCFLAGS'] = '-d'
698main['YACCHXXFILESUFFIX'] = '.hh'
699
700# Do this after we save setting back, or else we'll tack on an
701# extra 'qdo' every time we run scons.
702if main['BATCH']:
703    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
704    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
705    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
706    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
707    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
708
709if sys.platform == 'cygwin':
710    # cygwin has some header file issues...
711    main.Append(CCFLAGS=["-Wno-uninitialized"])
712
713# Check for the protobuf compiler
714protoc_version = readCommand([main['PROTOC'], '--version'],
715                             exception='').split()
716
717# First two words should be "libprotoc x.y.z"
718if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
719    print termcap.Yellow + termcap.Bold + \
720        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
721        '         Please install protobuf-compiler for tracing support.' + \
722        termcap.Normal
723    main['PROTOC'] = False
724else:
725    # Based on the availability of the compress stream wrappers,
726    # require 2.1.0
727    min_protoc_version = '2.1.0'
728    if compareVersions(protoc_version[1], min_protoc_version) < 0:
729        print termcap.Yellow + termcap.Bold + \
730            'Warning: protoc version', min_protoc_version, \
731            'or newer required.\n' + \
732            '         Installed version:', protoc_version[1], \
733            termcap.Normal
734        main['PROTOC'] = False
735    else:
736        # Attempt to determine the appropriate include path and
737        # library path using pkg-config, that means we also need to
738        # check for pkg-config. Note that it is possible to use
739        # protobuf without the involvement of pkg-config. Later on we
740        # check go a library config check and at that point the test
741        # will fail if libprotobuf cannot be found.
742        if readCommand(['pkg-config', '--version'], exception=''):
743            try:
744                # Attempt to establish what linking flags to add for protobuf
745                # using pkg-config
746                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
747            except:
748                print termcap.Yellow + termcap.Bold + \
749                    'Warning: pkg-config could not get protobuf flags.' + \
750                    termcap.Normal
751
752# Check for SWIG
753if not main.has_key('SWIG'):
754    print 'Error: SWIG utility not found.'
755    print '       Please install (see http://www.swig.org) and retry.'
756    Exit(1)
757
758# Check for appropriate SWIG version
759swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
760# First 3 words should be "SWIG Version x.y.z"
761if len(swig_version) < 3 or \
762        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
763    print 'Error determining SWIG version.'
764    Exit(1)
765
766min_swig_version = '2.0.4'
767if compareVersions(swig_version[2], min_swig_version) < 0:
768    print 'Error: SWIG version', min_swig_version, 'or newer required.'
769    print '       Installed version:', swig_version[2]
770    Exit(1)
771
772# Check for known incompatibilities. The standard library shipped with
773# gcc >= 4.9 does not play well with swig versions prior to 3.0
774if main['GCC'] and compareVersions(gcc_version, '4.9') >= 0 and \
775        compareVersions(swig_version[2], '3.0') < 0:
776    print termcap.Yellow + termcap.Bold + \
777        'Warning: This combination of gcc and swig have' + \
778        ' known incompatibilities.\n' + \
779        '         If you encounter build problems, please update ' + \
780        'swig to 3.0 or later.' + \
781        termcap.Normal
782
783# Set up SWIG flags & scanner
784swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
785main.Append(SWIGFLAGS=swig_flags)
786
787# Check for 'timeout' from GNU coreutils.  If present, regressions
788# will be run with a time limit.
789TIMEOUT_version = readCommand(['timeout', '--version'], exception=False)
790main['TIMEOUT'] = TIMEOUT_version and TIMEOUT_version.find('timeout') == 0
791
792# filter out all existing swig scanners, they mess up the dependency
793# stuff for some reason
794scanners = []
795for scanner in main['SCANNERS']:
796    skeys = scanner.skeys
797    if skeys == '.i':
798        continue
799
800    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
801        continue
802
803    scanners.append(scanner)
804
805# add the new swig scanner that we like better
806from SCons.Scanner import ClassicCPP as CPPScanner
807swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
808scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
809
810# replace the scanners list that has what we want
811main['SCANNERS'] = scanners
812
813# Add a custom Check function to the Configure context so that we can
814# figure out if the compiler adds leading underscores to global
815# variables.  This is needed for the autogenerated asm files that we
816# use for embedding the python code.
817def CheckLeading(context):
818    context.Message("Checking for leading underscore in global variables...")
819    # 1) Define a global variable called x from asm so the C compiler
820    #    won't change the symbol at all.
821    # 2) Declare that variable.
822    # 3) Use the variable
823    #
824    # If the compiler prepends an underscore, this will successfully
825    # link because the external symbol 'x' will be called '_x' which
826    # was defined by the asm statement.  If the compiler does not
827    # prepend an underscore, this will not successfully link because
828    # '_x' will have been defined by assembly, while the C portion of
829    # the code will be trying to use 'x'
830    ret = context.TryLink('''
831        asm(".globl _x; _x: .byte 0");
832        extern int x;
833        int main() { return x; }
834        ''', extension=".c")
835    context.env.Append(LEADING_UNDERSCORE=ret)
836    context.Result(ret)
837    return ret
838
839# Add a custom Check function to test for structure members.
840def CheckMember(context, include, decl, member, include_quotes="<>"):
841    context.Message("Checking for member %s in %s..." %
842                    (member, decl))
843    text = """
844#include %(header)s
845int main(){
846  %(decl)s test;
847  (void)test.%(member)s;
848  return 0;
849};
850""" % { "header" : include_quotes[0] + include + include_quotes[1],
851        "decl" : decl,
852        "member" : member,
853        }
854
855    ret = context.TryCompile(text, extension=".cc")
856    context.Result(ret)
857    return ret
858
859# Platform-specific configuration.  Note again that we assume that all
860# builds under a given build root run on the same host platform.
861conf = Configure(main,
862                 conf_dir = joinpath(build_root, '.scons_config'),
863                 log_file = joinpath(build_root, 'scons_config.log'),
864                 custom_tests = {
865        'CheckLeading' : CheckLeading,
866        'CheckMember' : CheckMember,
867        })
868
869# Check for leading underscores.  Don't really need to worry either
870# way so don't need to check the return code.
871conf.CheckLeading()
872
873# Check if we should compile a 64 bit binary on Mac OS X/Darwin
874try:
875    import platform
876    uname = platform.uname()
877    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
878        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
879            main.Append(CCFLAGS=['-arch', 'x86_64'])
880            main.Append(CFLAGS=['-arch', 'x86_64'])
881            main.Append(LINKFLAGS=['-arch', 'x86_64'])
882            main.Append(ASFLAGS=['-arch', 'x86_64'])
883except:
884    pass
885
886# Recent versions of scons substitute a "Null" object for Configure()
887# when configuration isn't necessary, e.g., if the "--help" option is
888# present.  Unfortuantely this Null object always returns false,
889# breaking all our configuration checks.  We replace it with our own
890# more optimistic null object that returns True instead.
891if not conf:
892    def NullCheck(*args, **kwargs):
893        return True
894
895    class NullConf:
896        def __init__(self, env):
897            self.env = env
898        def Finish(self):
899            return self.env
900        def __getattr__(self, mname):
901            return NullCheck
902
903    conf = NullConf(main)
904
905# Cache build files in the supplied directory.
906if main['M5_BUILD_CACHE']:
907    print 'Using build cache located at', main['M5_BUILD_CACHE']
908    CacheDir(main['M5_BUILD_CACHE'])
909
910if not GetOption('without_python'):
911    # Find Python include and library directories for embedding the
912    # interpreter. We rely on python-config to resolve the appropriate
913    # includes and linker flags. ParseConfig does not seem to understand
914    # the more exotic linker flags such as -Xlinker and -export-dynamic so
915    # we add them explicitly below. If you want to link in an alternate
916    # version of python, see above for instructions on how to invoke
917    # scons with the appropriate PATH set.
918    #
919    # First we check if python2-config exists, else we use python-config
920    python_config = readCommand(['which', 'python2-config'],
921                                exception='').strip()
922    if not os.path.exists(python_config):
923        python_config = readCommand(['which', 'python-config'],
924                                    exception='').strip()
925    py_includes = readCommand([python_config, '--includes'],
926                              exception='').split()
927    # Strip the -I from the include folders before adding them to the
928    # CPPPATH
929    main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
930
931    # Read the linker flags and split them into libraries and other link
932    # flags. The libraries are added later through the call the CheckLib.
933    py_ld_flags = readCommand([python_config, '--ldflags'],
934        exception='').split()
935    py_libs = []
936    for lib in py_ld_flags:
937         if not lib.startswith('-l'):
938             main.Append(LINKFLAGS=[lib])
939         else:
940             lib = lib[2:]
941             if lib not in py_libs:
942                 py_libs.append(lib)
943
944    # verify that this stuff works
945    if not conf.CheckHeader('Python.h', '<>'):
946        print "Error: can't find Python.h header in", py_includes
947        print "Install Python headers (package python-dev on Ubuntu and RedHat)"
948        Exit(1)
949
950    for lib in py_libs:
951        if not conf.CheckLib(lib):
952            print "Error: can't find library %s required by python" % lib
953            Exit(1)
954
955# On Solaris you need to use libsocket for socket ops
956if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
957   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
958       print "Can't find library with socket calls (e.g. accept())"
959       Exit(1)
960
961# Check for zlib.  If the check passes, libz will be automatically
962# added to the LIBS environment variable.
963if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
964    print 'Error: did not find needed zlib compression library '\
965          'and/or zlib.h header file.'
966    print '       Please install zlib and try again.'
967    Exit(1)
968
969# If we have the protobuf compiler, also make sure we have the
970# development libraries. If the check passes, libprotobuf will be
971# automatically added to the LIBS environment variable. After
972# this, we can use the HAVE_PROTOBUF flag to determine if we have
973# got both protoc and libprotobuf available.
974main['HAVE_PROTOBUF'] = main['PROTOC'] and \
975    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
976                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
977
978# If we have the compiler but not the library, print another warning.
979if main['PROTOC'] and not main['HAVE_PROTOBUF']:
980    print termcap.Yellow + termcap.Bold + \
981        'Warning: did not find protocol buffer library and/or headers.\n' + \
982    '       Please install libprotobuf-dev for tracing support.' + \
983    termcap.Normal
984
985# Check for librt.
986have_posix_clock = \
987    conf.CheckLibWithHeader(None, 'time.h', 'C',
988                            'clock_nanosleep(0,0,NULL,NULL);') or \
989    conf.CheckLibWithHeader('rt', 'time.h', 'C',
990                            'clock_nanosleep(0,0,NULL,NULL);')
991
992have_posix_timers = \
993    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
994                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
995
996if not GetOption('without_tcmalloc'):
997    if conf.CheckLib('tcmalloc'):
998        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
999    elif conf.CheckLib('tcmalloc_minimal'):
1000        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
1001    else:
1002        print termcap.Yellow + termcap.Bold + \
1003              "You can get a 12% performance improvement by "\
1004              "installing tcmalloc (libgoogle-perftools-dev package "\
1005              "on Ubuntu or RedHat)." + termcap.Normal
1006
1007if not have_posix_clock:
1008    print "Can't find library for POSIX clocks."
1009
1010# Check for <fenv.h> (C99 FP environment control)
1011have_fenv = conf.CheckHeader('fenv.h', '<>')
1012if not have_fenv:
1013    print "Warning: Header file <fenv.h> not found."
1014    print "         This host has no IEEE FP rounding mode control."
1015
1016# Check if we should enable KVM-based hardware virtualization. The API
1017# we rely on exists since version 2.6.36 of the kernel, but somehow
1018# the KVM_API_VERSION does not reflect the change. We test for one of
1019# the types as a fall back.
1020have_kvm = conf.CheckHeader('linux/kvm.h', '<>') and \
1021    conf.CheckTypeSize('struct kvm_xsave', '#include <linux/kvm.h>') != 0
1022if not have_kvm:
1023    print "Info: Compatible header file <linux/kvm.h> not found, " \
1024        "disabling KVM support."
1025
1026# Check if the requested target ISA is compatible with the host
1027def is_isa_kvm_compatible(isa):
1028    isa_comp_table = {
1029        "arm" : ( "armv7l" ),
1030        "x86" : ( "x86_64" ),
1031        }
1032    try:
1033        import platform
1034        host_isa = platform.machine()
1035    except:
1036        print "Warning: Failed to determine host ISA."
1037        return False
1038
1039    return host_isa in isa_comp_table.get(isa, [])
1040
1041
1042# Check if the exclude_host attribute is available. We want this to
1043# get accurate instruction counts in KVM.
1044main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1045    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1046
1047
1048######################################################################
1049#
1050# Finish the configuration
1051#
1052main = conf.Finish()
1053
1054######################################################################
1055#
1056# Collect all non-global variables
1057#
1058
1059# Define the universe of supported ISAs
1060all_isa_list = [ ]
1061Export('all_isa_list')
1062
1063class CpuModel(object):
1064    '''The CpuModel class encapsulates everything the ISA parser needs to
1065    know about a particular CPU model.'''
1066
1067    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1068    dict = {}
1069
1070    # Constructor.  Automatically adds models to CpuModel.dict.
1071    def __init__(self, name, default=False):
1072        self.name = name           # name of model
1073
1074        # This cpu is enabled by default
1075        self.default = default
1076
1077        # Add self to dict
1078        if name in CpuModel.dict:
1079            raise AttributeError, "CpuModel '%s' already registered" % name
1080        CpuModel.dict[name] = self
1081
1082Export('CpuModel')
1083
1084# Sticky variables get saved in the variables file so they persist from
1085# one invocation to the next (unless overridden, in which case the new
1086# value becomes sticky).
1087sticky_vars = Variables(args=ARGUMENTS)
1088Export('sticky_vars')
1089
1090# Sticky variables that should be exported
1091export_vars = []
1092Export('export_vars')
1093
1094# For Ruby
1095all_protocols = []
1096Export('all_protocols')
1097protocol_dirs = []
1098Export('protocol_dirs')
1099slicc_includes = []
1100Export('slicc_includes')
1101
1102# Walk the tree and execute all SConsopts scripts that wil add to the
1103# above variables
1104if GetOption('verbose'):
1105    print "Reading SConsopts"
1106for bdir in [ base_dir ] + extras_dir_list:
1107    if not isdir(bdir):
1108        print "Error: directory '%s' does not exist" % bdir
1109        Exit(1)
1110    for root, dirs, files in os.walk(bdir):
1111        if 'SConsopts' in files:
1112            if GetOption('verbose'):
1113                print "Reading", joinpath(root, 'SConsopts')
1114            SConscript(joinpath(root, 'SConsopts'))
1115
1116all_isa_list.sort()
1117
1118sticky_vars.AddVariables(
1119    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1120    ListVariable('CPU_MODELS', 'CPU models',
1121                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1122                 sorted(CpuModel.dict.keys())),
1123    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1124                 False),
1125    BoolVariable('SS_COMPATIBLE_FP',
1126                 'Make floating-point results compatible with SimpleScalar',
1127                 False),
1128    BoolVariable('USE_SSE2',
1129                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1130                 False),
1131    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1132    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1133    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1134    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1135    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1136                  all_protocols),
1137    )
1138
1139# These variables get exported to #defines in config/*.hh (see src/SConscript).
1140export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
1141                'USE_POSIX_CLOCK', 'USE_KVM', 'PROTOCOL', 'HAVE_PROTOBUF',
1142                'HAVE_PERF_ATTR_EXCLUDE_HOST']
1143
1144###################################################
1145#
1146# Define a SCons builder for configuration flag headers.
1147#
1148###################################################
1149
1150# This function generates a config header file that #defines the
1151# variable symbol to the current variable setting (0 or 1).  The source
1152# operands are the name of the variable and a Value node containing the
1153# value of the variable.
1154def build_config_file(target, source, env):
1155    (variable, value) = [s.get_contents() for s in source]
1156    f = file(str(target[0]), 'w')
1157    print >> f, '#define', variable, value
1158    f.close()
1159    return None
1160
1161# Combine the two functions into a scons Action object.
1162config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1163
1164# The emitter munges the source & target node lists to reflect what
1165# we're really doing.
1166def config_emitter(target, source, env):
1167    # extract variable name from Builder arg
1168    variable = str(target[0])
1169    # True target is config header file
1170    target = joinpath('config', variable.lower() + '.hh')
1171    val = env[variable]
1172    if isinstance(val, bool):
1173        # Force value to 0/1
1174        val = int(val)
1175    elif isinstance(val, str):
1176        val = '"' + val + '"'
1177
1178    # Sources are variable name & value (packaged in SCons Value nodes)
1179    return ([target], [Value(variable), Value(val)])
1180
1181config_builder = Builder(emitter = config_emitter, action = config_action)
1182
1183main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1184
1185# libelf build is shared across all configs in the build root.
1186main.SConscript('ext/libelf/SConscript',
1187                variant_dir = joinpath(build_root, 'libelf'))
1188
1189# gzstream build is shared across all configs in the build root.
1190main.SConscript('ext/gzstream/SConscript',
1191                variant_dir = joinpath(build_root, 'gzstream'))
1192
1193# libfdt build is shared across all configs in the build root.
1194main.SConscript('ext/libfdt/SConscript',
1195                variant_dir = joinpath(build_root, 'libfdt'))
1196
1197# fputils build is shared across all configs in the build root.
1198main.SConscript('ext/fputils/SConscript',
1199                variant_dir = joinpath(build_root, 'fputils'))
1200
1201# DRAMSim2 build is shared across all configs in the build root.
1202main.SConscript('ext/dramsim2/SConscript',
1203                variant_dir = joinpath(build_root, 'dramsim2'))
1204
1205# DRAMPower build is shared across all configs in the build root.
1206main.SConscript('ext/drampower/SConscript',
1207                variant_dir = joinpath(build_root, 'drampower'))
1208
1209###################################################
1210#
1211# This function is used to set up a directory with switching headers
1212#
1213###################################################
1214
1215main['ALL_ISA_LIST'] = all_isa_list
1216all_isa_deps = {}
1217def make_switching_dir(dname, switch_headers, env):
1218    # Generate the header.  target[0] is the full path of the output
1219    # header to generate.  'source' is a dummy variable, since we get the
1220    # list of ISAs from env['ALL_ISA_LIST'].
1221    def gen_switch_hdr(target, source, env):
1222        fname = str(target[0])
1223        isa = env['TARGET_ISA'].lower()
1224        try:
1225            f = open(fname, 'w')
1226            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1227            f.close()
1228        except IOError:
1229            print "Failed to create %s" % fname
1230            raise
1231
1232    # Build SCons Action object. 'varlist' specifies env vars that this
1233    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1234    # should get re-executed.
1235    switch_hdr_action = MakeAction(gen_switch_hdr,
1236                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1237
1238    # Instantiate actions for each header
1239    for hdr in switch_headers:
1240        env.Command(hdr, [], switch_hdr_action)
1241
1242    isa_target = Dir('.').up().name.lower().replace('_', '-')
1243    env['PHONY_BASE'] = '#'+isa_target
1244    all_isa_deps[isa_target] = None
1245
1246Export('make_switching_dir')
1247
1248# all-isas -> all-deps -> all-environs -> all_targets
1249main.Alias('#all-isas', [])
1250main.Alias('#all-deps', '#all-isas')
1251
1252# Dummy target to ensure all environments are created before telling
1253# SCons what to actually make (the command line arguments).  We attach
1254# them to the dependence graph after the environments are complete.
1255ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1256def environsComplete(target, source, env):
1257    for t in ORIG_BUILD_TARGETS:
1258        main.Depends('#all-targets', t)
1259
1260# Each build/* switching_dir attaches its *-environs target to #all-environs.
1261main.Append(BUILDERS = {'CompleteEnvirons' :
1262                        Builder(action=MakeAction(environsComplete, None))})
1263main.CompleteEnvirons('#all-environs', [])
1264
1265def doNothing(**ignored): pass
1266main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1267
1268# The final target to which all the original targets ultimately get attached.
1269main.Dummy('#all-targets', '#all-environs')
1270BUILD_TARGETS[:] = ['#all-targets']
1271
1272###################################################
1273#
1274# Define build environments for selected configurations.
1275#
1276###################################################
1277
1278for variant_path in variant_paths:
1279    if not GetOption('silent'):
1280        print "Building in", variant_path
1281
1282    # Make a copy of the build-root environment to use for this config.
1283    env = main.Clone()
1284    env['BUILDDIR'] = variant_path
1285
1286    # variant_dir is the tail component of build path, and is used to
1287    # determine the build parameters (e.g., 'ALPHA_SE')
1288    (build_root, variant_dir) = splitpath(variant_path)
1289
1290    # Set env variables according to the build directory config.
1291    sticky_vars.files = []
1292    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1293    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1294    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1295    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1296    if isfile(current_vars_file):
1297        sticky_vars.files.append(current_vars_file)
1298        if not GetOption('silent'):
1299            print "Using saved variables file %s" % current_vars_file
1300    else:
1301        # Build dir-specific variables file doesn't exist.
1302
1303        # Make sure the directory is there so we can create it later
1304        opt_dir = dirname(current_vars_file)
1305        if not isdir(opt_dir):
1306            mkdir(opt_dir)
1307
1308        # Get default build variables from source tree.  Variables are
1309        # normally determined by name of $VARIANT_DIR, but can be
1310        # overridden by '--default=' arg on command line.
1311        default = GetOption('default')
1312        opts_dir = joinpath(main.root.abspath, 'build_opts')
1313        if default:
1314            default_vars_files = [joinpath(build_root, 'variables', default),
1315                                  joinpath(opts_dir, default)]
1316        else:
1317            default_vars_files = [joinpath(opts_dir, variant_dir)]
1318        existing_files = filter(isfile, default_vars_files)
1319        if existing_files:
1320            default_vars_file = existing_files[0]
1321            sticky_vars.files.append(default_vars_file)
1322            print "Variables file %s not found,\n  using defaults in %s" \
1323                  % (current_vars_file, default_vars_file)
1324        else:
1325            print "Error: cannot find variables file %s or " \
1326                  "default file(s) %s" \
1327                  % (current_vars_file, ' or '.join(default_vars_files))
1328            Exit(1)
1329
1330    # Apply current variable settings to env
1331    sticky_vars.Update(env)
1332
1333    help_texts["local_vars"] += \
1334        "Build variables for %s:\n" % variant_dir \
1335                 + sticky_vars.GenerateHelpText(env)
1336
1337    # Process variable settings.
1338
1339    if not have_fenv and env['USE_FENV']:
1340        print "Warning: <fenv.h> not available; " \
1341              "forcing USE_FENV to False in", variant_dir + "."
1342        env['USE_FENV'] = False
1343
1344    if not env['USE_FENV']:
1345        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1346        print "         FP results may deviate slightly from other platforms."
1347
1348    if env['EFENCE']:
1349        env.Append(LIBS=['efence'])
1350
1351    if env['USE_KVM']:
1352        if not have_kvm:
1353            print "Warning: Can not enable KVM, host seems to lack KVM support"
1354            env['USE_KVM'] = False
1355        elif not have_posix_timers:
1356            print "Warning: Can not enable KVM, host seems to lack support " \
1357                "for POSIX timers"
1358            env['USE_KVM'] = False
1359        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1360            print "Info: KVM support disabled due to unsupported host and " \
1361                "target ISA combination"
1362            env['USE_KVM'] = False
1363
1364    # Warn about missing optional functionality
1365    if env['USE_KVM']:
1366        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1367            print "Warning: perf_event headers lack support for the " \
1368                "exclude_host attribute. KVM instruction counts will " \
1369                "be inaccurate."
1370
1371    # Save sticky variable settings back to current variables file
1372    sticky_vars.Save(current_vars_file, env)
1373
1374    if env['USE_SSE2']:
1375        env.Append(CCFLAGS=['-msse2'])
1376
1377    # The src/SConscript file sets up the build rules in 'env' according
1378    # to the configured variables.  It returns a list of environments,
1379    # one for each variant build (debug, opt, etc.)
1380    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1381
1382def pairwise(iterable):
1383    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1384    a, b = itertools.tee(iterable)
1385    b.next()
1386    return itertools.izip(a, b)
1387
1388# Create false dependencies so SCons will parse ISAs, establish
1389# dependencies, and setup the build Environments serially. Either
1390# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1391# greater than 1. It appears to be standard race condition stuff; it
1392# doesn't always fail, but usually, and the behaviors are different.
1393# Every time I tried to remove this, builds would fail in some
1394# creative new way. So, don't do that. You'll want to, though, because
1395# tests/SConscript takes a long time to make its Environments.
1396for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1397    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1398    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1399
1400# base help text
1401Help('''
1402Usage: scons [scons options] [build variables] [target(s)]
1403
1404Extra scons options:
1405%(options)s
1406
1407Global build variables:
1408%(global_vars)s
1409
1410%(local_vars)s
1411''' % help_texts)
1412