SConstruct revision 11500:024291dab733
1# -*- mode:python -*-
2
3# Copyright (c) 2013, 2015, 2016 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 shutil
116import subprocess
117import sys
118
119from os import mkdir, environ
120from os.path import abspath, basename, dirname, expanduser, normpath
121from os.path import exists,  isdir, isfile
122from os.path import join as joinpath, split as splitpath
123
124# SCons includes
125import SCons
126import SCons.Node
127
128extra_python_paths = [
129    Dir('src/python').srcnode().abspath, # gem5 includes
130    Dir('ext/ply').srcnode().abspath, # ply is used by several files
131    ]
132
133sys.path[1:1] = extra_python_paths
134
135from m5.util import compareVersions, readCommand
136from m5.util.terminal import get_termcap
137
138help_texts = {
139    "options" : "",
140    "global_vars" : "",
141    "local_vars" : ""
142}
143
144Export("help_texts")
145
146
147# There's a bug in scons in that (1) by default, the help texts from
148# AddOption() are supposed to be displayed when you type 'scons -h'
149# and (2) you can override the help displayed by 'scons -h' using the
150# Help() function, but these two features are incompatible: once
151# you've overridden the help text using Help(), there's no way to get
152# at the help texts from AddOptions.  See:
153#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
154#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
155# This hack lets us extract the help text from AddOptions and
156# re-inject it via Help().  Ideally someday this bug will be fixed and
157# we can just use AddOption directly.
158def AddLocalOption(*args, **kwargs):
159    col_width = 30
160
161    help = "  " + ", ".join(args)
162    if "help" in kwargs:
163        length = len(help)
164        if length >= col_width:
165            help += "\n" + " " * col_width
166        else:
167            help += " " * (col_width - length)
168        help += kwargs["help"]
169    help_texts["options"] += help + "\n"
170
171    AddOption(*args, **kwargs)
172
173AddLocalOption('--colors', dest='use_colors', action='store_true',
174               help="Add color to abbreviated scons output")
175AddLocalOption('--no-colors', dest='use_colors', action='store_false',
176               help="Don't add color to abbreviated scons output")
177AddLocalOption('--with-cxx-config', dest='with_cxx_config',
178               action='store_true',
179               help="Build with support for C++-based configuration")
180AddLocalOption('--default', dest='default', type='string', action='store',
181               help='Override which build_opts file to use for defaults')
182AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
183               help='Disable style checking hooks')
184AddLocalOption('--no-lto', dest='no_lto', action='store_true',
185               help='Disable Link-Time Optimization for fast')
186AddLocalOption('--update-ref', dest='update_ref', action='store_true',
187               help='Update test reference outputs')
188AddLocalOption('--verbose', dest='verbose', action='store_true',
189               help='Print full tool command lines')
190AddLocalOption('--without-python', dest='without_python',
191               action='store_true',
192               help='Build without Python configuration support')
193AddLocalOption('--without-tcmalloc', dest='without_tcmalloc',
194               action='store_true',
195               help='Disable linking against tcmalloc')
196AddLocalOption('--with-ubsan', dest='with_ubsan', action='store_true',
197               help='Build with Undefined Behavior Sanitizer if available')
198AddLocalOption('--with-asan', dest='with_asan', action='store_true',
199               help='Build with Address Sanitizer if available')
200
201termcap = get_termcap(GetOption('use_colors'))
202
203########################################################################
204#
205# Set up the main build environment.
206#
207########################################################################
208
209# export TERM so that clang reports errors in color
210use_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH',
211                 'LIBRARY_PATH', 'PATH', 'PKG_CONFIG_PATH', 'PROTOC',
212                 'PYTHONPATH', 'RANLIB', 'SWIG', 'TERM' ])
213
214use_prefixes = [
215    "ASAN_",           # address sanitizer symbolizer path and settings
216    "CCACHE_",         # ccache (caching compiler wrapper) configuration
217    "CCC_",            # clang static analyzer configuration
218    "DISTCC_",         # distcc (distributed compiler wrapper) configuration
219    "INCLUDE_SERVER_", # distcc pump server settings
220    "M5",              # M5 configuration (e.g., path to kernels)
221    ]
222
223use_env = {}
224for key,val in sorted(os.environ.iteritems()):
225    if key in use_vars or \
226            any([key.startswith(prefix) for prefix in use_prefixes]):
227        use_env[key] = val
228
229# Tell scons to avoid implicit command dependencies to avoid issues
230# with the param wrappes being compiled twice (see
231# http://scons.tigris.org/issues/show_bug.cgi?id=2811)
232main = Environment(ENV=use_env, IMPLICIT_COMMAND_DEPENDENCIES=0)
233main.Decider('MD5-timestamp')
234main.root = Dir(".")         # The current directory (where this file lives).
235main.srcdir = Dir("src")     # The source directory
236
237main_dict_keys = main.Dictionary().keys()
238
239# Check that we have a C/C++ compiler
240if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
241    print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
242    Exit(1)
243
244# Check that swig is present
245if not 'SWIG' in main_dict_keys:
246    print "swig is not installed (package swig on Ubuntu and RedHat)"
247    Exit(1)
248
249# add useful python code PYTHONPATH so it can be used by subprocesses
250# as well
251main.AppendENVPath('PYTHONPATH', extra_python_paths)
252
253########################################################################
254#
255# Mercurial Stuff.
256#
257# If the gem5 directory is a mercurial repository, we should do some
258# extra things.
259#
260########################################################################
261
262hgdir = main.root.Dir(".hg")
263
264
265style_message = """
266You're missing the gem5 style hook, which automatically checks your code
267against the gem5 style rules on %s.
268This script will now install the hook in your %s.
269Press enter to continue, or ctrl-c to abort: """
270
271mercurial_style_message = style_message % ("hg commit and qrefresh commands",
272                                           ".hg/hgrc file")
273git_style_message = style_message % ("'git commit'",
274                                     ".git/hooks/ directory")
275
276mercurial_style_upgrade_message = """
277Your Mercurial style hooks are not up-to-date. This script will now
278try to automatically update them. A backup of your hgrc will be saved
279in .hg/hgrc.old.
280Press enter to continue, or ctrl-c to abort: """
281
282mercurial_style_hook = """
283# The following lines were automatically added by gem5/SConstruct
284# to provide the gem5 style-checking hooks
285[extensions]
286hgstyle = %s/util/hgstyle.py
287
288[hooks]
289pretxncommit.style = python:hgstyle.check_style
290pre-qrefresh.style = python:hgstyle.check_style
291# End of SConstruct additions
292
293""" % (main.root.abspath)
294
295mercurial_lib_not_found = """
296Mercurial libraries cannot be found, ignoring style hook.  If
297you are a gem5 developer, please fix this and run the style
298hook. It is important.
299"""
300
301# Check for style hook and prompt for installation if it's not there.
302# Skip this if --ignore-style was specified, there's no interactive
303# terminal to prompt, or no recognized revision control system can be
304# found.
305ignore_style = GetOption('ignore_style') or not sys.stdin.isatty()
306
307# Try wire up Mercurial to the style hooks
308if not ignore_style and hgdir.exists():
309    style_hook = True
310    style_hooks = tuple()
311    hgrc = hgdir.File('hgrc')
312    hgrc_old = hgdir.File('hgrc.old')
313    try:
314        from mercurial import ui
315        ui = ui.ui()
316        ui.readconfig(hgrc.abspath)
317        style_hooks = (ui.config('hooks', 'pretxncommit.style', None),
318                       ui.config('hooks', 'pre-qrefresh.style', None))
319        style_hook = all(style_hooks)
320        style_extension = ui.config('extensions', 'style', None)
321    except ImportError:
322        print mercurial_lib_not_found
323
324    if "python:style.check_style" in style_hooks:
325        # Try to upgrade the style hooks
326        print mercurial_style_upgrade_message
327        # continue unless user does ctrl-c/ctrl-d etc.
328        try:
329            raw_input()
330        except:
331            print "Input exception, exiting scons.\n"
332            sys.exit(1)
333        shutil.copyfile(hgrc.abspath, hgrc_old.abspath)
334        re_style_hook = re.compile(r"^([^=#]+)\.style\s*=\s*([^#\s]+).*")
335        re_style_extension = re.compile("style\s*=\s*([^#\s]+).*")
336        old, new = open(hgrc_old.abspath, 'r'), open(hgrc.abspath, 'w')
337        for l in old:
338            m_hook = re_style_hook.match(l)
339            m_ext = re_style_extension.match(l)
340            if m_hook:
341                hook, check = m_hook.groups()
342                if check != "python:style.check_style":
343                    print "Warning: %s.style is using a non-default " \
344                        "checker: %s" % (hook, check)
345                if hook not in ("pretxncommit", "pre-qrefresh"):
346                    print "Warning: Updating unknown style hook: %s" % hook
347
348                l = "%s.style = python:hgstyle.check_style\n" % hook
349            elif m_ext and m_ext.group(1) == style_extension:
350                l = "hgstyle = %s/util/hgstyle.py\n" % main.root.abspath
351
352            new.write(l)
353    elif not style_hook:
354        print mercurial_style_message,
355        # continue unless user does ctrl-c/ctrl-d etc.
356        try:
357            raw_input()
358        except:
359            print "Input exception, exiting scons.\n"
360            sys.exit(1)
361        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
362        print "Adding style hook to", hgrc_path, "\n"
363        try:
364            with open(hgrc_path, 'a') as f:
365                f.write(mercurial_style_hook)
366        except:
367            print "Error updating", hgrc_path
368            sys.exit(1)
369
370def install_git_style_hooks():
371    try:
372        gitdir = Dir(readCommand(
373            ["git", "rev-parse", "--git-dir"]).strip("\n"))
374    except Exception, e:
375        print "Warning: Failed to find git repo directory: %s" % e
376        return
377
378    git_hooks = gitdir.Dir("hooks")
379    git_pre_commit_hook = git_hooks.File("pre-commit")
380    git_style_script = File("util/git-pre-commit.py")
381
382    if git_pre_commit_hook.exists():
383        return
384
385    print git_style_message,
386    try:
387        raw_input()
388    except:
389        print "Input exception, exiting scons.\n"
390        sys.exit(1)
391
392    if not git_hooks.exists():
393        mkdir(git_hooks.get_abspath())
394
395    # Use a relative symlink if the hooks live in the source directory
396    if git_pre_commit_hook.is_under(main.root):
397        script_path = os.path.relpath(
398            git_style_script.get_abspath(),
399            git_pre_commit_hook.Dir(".").get_abspath())
400    else:
401        script_path = git_style_script.get_abspath()
402
403    try:
404        os.symlink(script_path, git_pre_commit_hook.get_abspath())
405    except:
406        print "Error updating git pre-commit hook"
407        raise
408
409# Try to wire up git to the style hooks
410if not ignore_style and main.root.Entry(".git").exists():
411    install_git_style_hooks()
412
413###################################################
414#
415# Figure out which configurations to set up based on the path(s) of
416# the target(s).
417#
418###################################################
419
420# Find default configuration & binary.
421Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
422
423# helper function: find last occurrence of element in list
424def rfind(l, elt, offs = -1):
425    for i in range(len(l)+offs, 0, -1):
426        if l[i] == elt:
427            return i
428    raise ValueError, "element not found"
429
430# Take a list of paths (or SCons Nodes) and return a list with all
431# paths made absolute and ~-expanded.  Paths will be interpreted
432# relative to the launch directory unless a different root is provided
433def makePathListAbsolute(path_list, root=GetLaunchDir()):
434    return [abspath(joinpath(root, expanduser(str(p))))
435            for p in path_list]
436
437# Each target must have 'build' in the interior of the path; the
438# directory below this will determine the build parameters.  For
439# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
440# recognize that ALPHA_SE specifies the configuration because it
441# follow 'build' in the build path.
442
443# The funky assignment to "[:]" is needed to replace the list contents
444# in place rather than reassign the symbol to a new list, which
445# doesn't work (obviously!).
446BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
447
448# Generate a list of the unique build roots and configs that the
449# collected targets reference.
450variant_paths = []
451build_root = None
452for t in BUILD_TARGETS:
453    path_dirs = t.split('/')
454    try:
455        build_top = rfind(path_dirs, 'build', -2)
456    except:
457        print "Error: no non-leaf 'build' dir found on target path", t
458        Exit(1)
459    this_build_root = joinpath('/',*path_dirs[:build_top+1])
460    if not build_root:
461        build_root = this_build_root
462    else:
463        if this_build_root != build_root:
464            print "Error: build targets not under same build root\n"\
465                  "  %s\n  %s" % (build_root, this_build_root)
466            Exit(1)
467    variant_path = joinpath('/',*path_dirs[:build_top+2])
468    if variant_path not in variant_paths:
469        variant_paths.append(variant_path)
470
471# Make sure build_root exists (might not if this is the first build there)
472if not isdir(build_root):
473    mkdir(build_root)
474main['BUILDROOT'] = build_root
475
476Export('main')
477
478main.SConsignFile(joinpath(build_root, "sconsign"))
479
480# Default duplicate option is to use hard links, but this messes up
481# when you use emacs to edit a file in the target dir, as emacs moves
482# file to file~ then copies to file, breaking the link.  Symbolic
483# (soft) links work better.
484main.SetOption('duplicate', 'soft-copy')
485
486#
487# Set up global sticky variables... these are common to an entire build
488# tree (not specific to a particular build like ALPHA_SE)
489#
490
491global_vars_file = joinpath(build_root, 'variables.global')
492
493global_vars = Variables(global_vars_file, args=ARGUMENTS)
494
495global_vars.AddVariables(
496    ('CC', 'C compiler', environ.get('CC', main['CC'])),
497    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
498    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
499    ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
500    ('BATCH', 'Use batch pool for build and tests', False),
501    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
502    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
503    ('EXTRAS', 'Add extra directories to the compilation', '')
504    )
505
506# Update main environment with values from ARGUMENTS & global_vars_file
507global_vars.Update(main)
508help_texts["global_vars"] += global_vars.GenerateHelpText(main)
509
510# Save sticky variable settings back to current variables file
511global_vars.Save(global_vars_file, main)
512
513# Parse EXTRAS variable to build list of all directories where we're
514# look for sources etc.  This list is exported as extras_dir_list.
515base_dir = main.srcdir.abspath
516if main['EXTRAS']:
517    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
518else:
519    extras_dir_list = []
520
521Export('base_dir')
522Export('extras_dir_list')
523
524# the ext directory should be on the #includes path
525main.Append(CPPPATH=[Dir('ext')])
526
527def strip_build_path(path, env):
528    path = str(path)
529    variant_base = env['BUILDROOT'] + os.path.sep
530    if path.startswith(variant_base):
531        path = path[len(variant_base):]
532    elif path.startswith('build/'):
533        path = path[6:]
534    return path
535
536# Generate a string of the form:
537#   common/path/prefix/src1, src2 -> tgt1, tgt2
538# to print while building.
539class Transform(object):
540    # all specific color settings should be here and nowhere else
541    tool_color = termcap.Normal
542    pfx_color = termcap.Yellow
543    srcs_color = termcap.Yellow + termcap.Bold
544    arrow_color = termcap.Blue + termcap.Bold
545    tgts_color = termcap.Yellow + termcap.Bold
546
547    def __init__(self, tool, max_sources=99):
548        self.format = self.tool_color + (" [%8s] " % tool) \
549                      + self.pfx_color + "%s" \
550                      + self.srcs_color + "%s" \
551                      + self.arrow_color + " -> " \
552                      + self.tgts_color + "%s" \
553                      + termcap.Normal
554        self.max_sources = max_sources
555
556    def __call__(self, target, source, env, for_signature=None):
557        # truncate source list according to max_sources param
558        source = source[0:self.max_sources]
559        def strip(f):
560            return strip_build_path(str(f), env)
561        if len(source) > 0:
562            srcs = map(strip, source)
563        else:
564            srcs = ['']
565        tgts = map(strip, target)
566        # surprisingly, os.path.commonprefix is a dumb char-by-char string
567        # operation that has nothing to do with paths.
568        com_pfx = os.path.commonprefix(srcs + tgts)
569        com_pfx_len = len(com_pfx)
570        if com_pfx:
571            # do some cleanup and sanity checking on common prefix
572            if com_pfx[-1] == ".":
573                # prefix matches all but file extension: ok
574                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
575                com_pfx = com_pfx[0:-1]
576            elif com_pfx[-1] == "/":
577                # common prefix is directory path: OK
578                pass
579            else:
580                src0_len = len(srcs[0])
581                tgt0_len = len(tgts[0])
582                if src0_len == com_pfx_len:
583                    # source is a substring of target, OK
584                    pass
585                elif tgt0_len == com_pfx_len:
586                    # target is a substring of source, need to back up to
587                    # avoid empty string on RHS of arrow
588                    sep_idx = com_pfx.rfind(".")
589                    if sep_idx != -1:
590                        com_pfx = com_pfx[0:sep_idx]
591                    else:
592                        com_pfx = ''
593                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
594                    # still splitting at file extension: ok
595                    pass
596                else:
597                    # probably a fluke; ignore it
598                    com_pfx = ''
599        # recalculate length in case com_pfx was modified
600        com_pfx_len = len(com_pfx)
601        def fmt(files):
602            f = map(lambda s: s[com_pfx_len:], files)
603            return ', '.join(f)
604        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
605
606Export('Transform')
607
608# enable the regression script to use the termcap
609main['TERMCAP'] = termcap
610
611if GetOption('verbose'):
612    def MakeAction(action, string, *args, **kwargs):
613        return Action(action, *args, **kwargs)
614else:
615    MakeAction = Action
616    main['CCCOMSTR']        = Transform("CC")
617    main['CXXCOMSTR']       = Transform("CXX")
618    main['ASCOMSTR']        = Transform("AS")
619    main['SWIGCOMSTR']      = Transform("SWIG")
620    main['ARCOMSTR']        = Transform("AR", 0)
621    main['LINKCOMSTR']      = Transform("LINK", 0)
622    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
623    main['M4COMSTR']        = Transform("M4")
624    main['SHCCCOMSTR']      = Transform("SHCC")
625    main['SHCXXCOMSTR']     = Transform("SHCXX")
626Export('MakeAction')
627
628# Initialize the Link-Time Optimization (LTO) flags
629main['LTO_CCFLAGS'] = []
630main['LTO_LDFLAGS'] = []
631
632# According to the readme, tcmalloc works best if the compiler doesn't
633# assume that we're using the builtin malloc and friends. These flags
634# are compiler-specific, so we need to set them after we detect which
635# compiler we're using.
636main['TCMALLOC_CCFLAGS'] = []
637
638CXX_version = readCommand([main['CXX'],'--version'], exception=False)
639CXX_V = readCommand([main['CXX'],'-V'], exception=False)
640
641main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
642main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
643if main['GCC'] + main['CLANG'] > 1:
644    print 'Error: How can we have two at the same time?'
645    Exit(1)
646
647# Set up default C++ compiler flags
648if main['GCC'] or main['CLANG']:
649    # As gcc and clang share many flags, do the common parts here
650    main.Append(CCFLAGS=['-pipe'])
651    main.Append(CCFLAGS=['-fno-strict-aliasing'])
652    # Enable -Wall and -Wextra and then disable the few warnings that
653    # we consistently violate
654    main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
655                         '-Wno-sign-compare', '-Wno-unused-parameter'])
656    # We always compile using C++11
657    main.Append(CXXFLAGS=['-std=c++11'])
658else:
659    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
660    print "Don't know what compiler options to use for your compiler."
661    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
662    print termcap.Yellow + '       version:' + termcap.Normal,
663    if not CXX_version:
664        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
665               termcap.Normal
666    else:
667        print CXX_version.replace('\n', '<nl>')
668    print "       If you're trying to use a compiler other than GCC"
669    print "       or clang, there appears to be something wrong with your"
670    print "       environment."
671    print "       "
672    print "       If you are trying to use a compiler other than those listed"
673    print "       above you will need to ease fix SConstruct and "
674    print "       src/SConscript to support that compiler."
675    Exit(1)
676
677if main['GCC']:
678    # Check for a supported version of gcc. >= 4.8 is chosen for its
679    # level of c++11 support. See
680    # http://gcc.gnu.org/projects/cxx0x.html for details.
681    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
682    if compareVersions(gcc_version, "4.8") < 0:
683        print 'Error: gcc version 4.8 or newer required.'
684        print '       Installed version:', gcc_version
685        Exit(1)
686
687    main['GCC_VERSION'] = gcc_version
688
689    # gcc from version 4.8 and above generates "rep; ret" instructions
690    # to avoid performance penalties on certain AMD chips. Older
691    # assemblers detect this as an error, "Error: expecting string
692    # instruction after `rep'"
693    as_version_raw = readCommand([main['AS'], '-v', '/dev/null'],
694                                 exception=False).split()
695
696    # version strings may contain extra distro-specific
697    # qualifiers, so play it safe and keep only what comes before
698    # the first hyphen
699    as_version = as_version_raw[-1].split('-')[0] if as_version_raw else None
700
701    if not as_version or compareVersions(as_version, "2.23") < 0:
702        print termcap.Yellow + termcap.Bold + \
703            'Warning: This combination of gcc and binutils have' + \
704            ' known incompatibilities.\n' + \
705            '         If you encounter build problems, please update ' + \
706            'binutils to 2.23.' + \
707            termcap.Normal
708
709    # Make sure we warn if the user has requested to compile with the
710    # Undefined Benahvior Sanitizer and this version of gcc does not
711    # support it.
712    if GetOption('with_ubsan') and \
713            compareVersions(gcc_version, '4.9') < 0:
714        print termcap.Yellow + termcap.Bold + \
715            'Warning: UBSan is only supported using gcc 4.9 and later.' + \
716            termcap.Normal
717
718    # Add the appropriate Link-Time Optimization (LTO) flags
719    # unless LTO is explicitly turned off. Note that these flags
720    # are only used by the fast target.
721    if not GetOption('no_lto'):
722        # Pass the LTO flag when compiling to produce GIMPLE
723        # output, we merely create the flags here and only append
724        # them later
725        main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
726
727        # Use the same amount of jobs for LTO as we are running
728        # scons with
729        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
730
731    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
732                                  '-fno-builtin-realloc', '-fno-builtin-free'])
733
734    # add option to check for undeclared overrides
735    if compareVersions(gcc_version, "5.0") > 0:
736        main.Append(CCFLAGS=['-Wno-error=suggest-override'])
737
738elif main['CLANG']:
739    # Check for a supported version of clang, >= 3.1 is needed to
740    # support similar features as gcc 4.8. See
741    # http://clang.llvm.org/cxx_status.html for details
742    clang_version_re = re.compile(".* version (\d+\.\d+)")
743    clang_version_match = clang_version_re.search(CXX_version)
744    if (clang_version_match):
745        clang_version = clang_version_match.groups()[0]
746        if compareVersions(clang_version, "3.1") < 0:
747            print 'Error: clang version 3.1 or newer required.'
748            print '       Installed version:', clang_version
749            Exit(1)
750    else:
751        print 'Error: Unable to determine clang version.'
752        Exit(1)
753
754    # clang has a few additional warnings that we disable, extraneous
755    # parantheses are allowed due to Ruby's printing of the AST,
756    # finally self assignments are allowed as the generated CPU code
757    # is relying on this
758    main.Append(CCFLAGS=['-Wno-parentheses',
759                         '-Wno-self-assign',
760                         # Some versions of libstdc++ (4.8?) seem to
761                         # use struct hash and class hash
762                         # interchangeably.
763                         '-Wno-mismatched-tags',
764                         ])
765
766    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
767
768    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
769    # opposed to libstdc++, as the later is dated.
770    if sys.platform == "darwin":
771        main.Append(CXXFLAGS=['-stdlib=libc++'])
772        main.Append(LIBS=['c++'])
773
774else:
775    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
776    print "Don't know what compiler options to use for your compiler."
777    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
778    print termcap.Yellow + '       version:' + termcap.Normal,
779    if not CXX_version:
780        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
781               termcap.Normal
782    else:
783        print CXX_version.replace('\n', '<nl>')
784    print "       If you're trying to use a compiler other than GCC"
785    print "       or clang, there appears to be something wrong with your"
786    print "       environment."
787    print "       "
788    print "       If you are trying to use a compiler other than those listed"
789    print "       above you will need to ease fix SConstruct and "
790    print "       src/SConscript to support that compiler."
791    Exit(1)
792
793# Set up common yacc/bison flags (needed for Ruby)
794main['YACCFLAGS'] = '-d'
795main['YACCHXXFILESUFFIX'] = '.hh'
796
797# Do this after we save setting back, or else we'll tack on an
798# extra 'qdo' every time we run scons.
799if main['BATCH']:
800    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
801    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
802    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
803    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
804    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
805
806if sys.platform == 'cygwin':
807    # cygwin has some header file issues...
808    main.Append(CCFLAGS=["-Wno-uninitialized"])
809
810# Check for the protobuf compiler
811protoc_version = readCommand([main['PROTOC'], '--version'],
812                             exception='').split()
813
814# First two words should be "libprotoc x.y.z"
815if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
816    print termcap.Yellow + termcap.Bold + \
817        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
818        '         Please install protobuf-compiler for tracing support.' + \
819        termcap.Normal
820    main['PROTOC'] = False
821else:
822    # Based on the availability of the compress stream wrappers,
823    # require 2.1.0
824    min_protoc_version = '2.1.0'
825    if compareVersions(protoc_version[1], min_protoc_version) < 0:
826        print termcap.Yellow + termcap.Bold + \
827            'Warning: protoc version', min_protoc_version, \
828            'or newer required.\n' + \
829            '         Installed version:', protoc_version[1], \
830            termcap.Normal
831        main['PROTOC'] = False
832    else:
833        # Attempt to determine the appropriate include path and
834        # library path using pkg-config, that means we also need to
835        # check for pkg-config. Note that it is possible to use
836        # protobuf without the involvement of pkg-config. Later on we
837        # check go a library config check and at that point the test
838        # will fail if libprotobuf cannot be found.
839        if readCommand(['pkg-config', '--version'], exception=''):
840            try:
841                # Attempt to establish what linking flags to add for protobuf
842                # using pkg-config
843                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
844            except:
845                print termcap.Yellow + termcap.Bold + \
846                    'Warning: pkg-config could not get protobuf flags.' + \
847                    termcap.Normal
848
849# Check for SWIG
850if not main.has_key('SWIG'):
851    print 'Error: SWIG utility not found.'
852    print '       Please install (see http://www.swig.org) and retry.'
853    Exit(1)
854
855# Check for appropriate SWIG version
856swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
857# First 3 words should be "SWIG Version x.y.z"
858if len(swig_version) < 3 or \
859        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
860    print 'Error determining SWIG version.'
861    Exit(1)
862
863min_swig_version = '2.0.4'
864if compareVersions(swig_version[2], min_swig_version) < 0:
865    print 'Error: SWIG version', min_swig_version, 'or newer required.'
866    print '       Installed version:', swig_version[2]
867    Exit(1)
868
869# Check for known incompatibilities. The standard library shipped with
870# gcc >= 4.9 does not play well with swig versions prior to 3.0
871if main['GCC'] and compareVersions(gcc_version, '4.9') >= 0 and \
872        compareVersions(swig_version[2], '3.0') < 0:
873    print termcap.Yellow + termcap.Bold + \
874        'Warning: This combination of gcc and swig have' + \
875        ' known incompatibilities.\n' + \
876        '         If you encounter build problems, please update ' + \
877        'swig to 3.0 or later.' + \
878        termcap.Normal
879
880# Set up SWIG flags & scanner
881swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
882main.Append(SWIGFLAGS=swig_flags)
883
884# Check for 'timeout' from GNU coreutils. If present, regressions will
885# be run with a time limit. We require version 8.13 since we rely on
886# support for the '--foreground' option.
887timeout_lines = readCommand(['timeout', '--version'],
888                            exception='').splitlines()
889# Get the first line and tokenize it
890timeout_version = timeout_lines[0].split() if timeout_lines else []
891main['TIMEOUT'] =  timeout_version and \
892    compareVersions(timeout_version[-1], '8.13') >= 0
893
894# filter out all existing swig scanners, they mess up the dependency
895# stuff for some reason
896scanners = []
897for scanner in main['SCANNERS']:
898    skeys = scanner.skeys
899    if skeys == '.i':
900        continue
901
902    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
903        continue
904
905    scanners.append(scanner)
906
907# add the new swig scanner that we like better
908from SCons.Scanner import ClassicCPP as CPPScanner
909swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
910scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
911
912# replace the scanners list that has what we want
913main['SCANNERS'] = scanners
914
915# Add a custom Check function to test for structure members.
916def CheckMember(context, include, decl, member, include_quotes="<>"):
917    context.Message("Checking for member %s in %s..." %
918                    (member, decl))
919    text = """
920#include %(header)s
921int main(){
922  %(decl)s test;
923  (void)test.%(member)s;
924  return 0;
925};
926""" % { "header" : include_quotes[0] + include + include_quotes[1],
927        "decl" : decl,
928        "member" : member,
929        }
930
931    ret = context.TryCompile(text, extension=".cc")
932    context.Result(ret)
933    return ret
934
935# Platform-specific configuration.  Note again that we assume that all
936# builds under a given build root run on the same host platform.
937conf = Configure(main,
938                 conf_dir = joinpath(build_root, '.scons_config'),
939                 log_file = joinpath(build_root, 'scons_config.log'),
940                 custom_tests = {
941        'CheckMember' : CheckMember,
942        })
943
944# Check if we should compile a 64 bit binary on Mac OS X/Darwin
945try:
946    import platform
947    uname = platform.uname()
948    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
949        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
950            main.Append(CCFLAGS=['-arch', 'x86_64'])
951            main.Append(CFLAGS=['-arch', 'x86_64'])
952            main.Append(LINKFLAGS=['-arch', 'x86_64'])
953            main.Append(ASFLAGS=['-arch', 'x86_64'])
954except:
955    pass
956
957# Recent versions of scons substitute a "Null" object for Configure()
958# when configuration isn't necessary, e.g., if the "--help" option is
959# present.  Unfortuantely this Null object always returns false,
960# breaking all our configuration checks.  We replace it with our own
961# more optimistic null object that returns True instead.
962if not conf:
963    def NullCheck(*args, **kwargs):
964        return True
965
966    class NullConf:
967        def __init__(self, env):
968            self.env = env
969        def Finish(self):
970            return self.env
971        def __getattr__(self, mname):
972            return NullCheck
973
974    conf = NullConf(main)
975
976# Cache build files in the supplied directory.
977if main['M5_BUILD_CACHE']:
978    print 'Using build cache located at', main['M5_BUILD_CACHE']
979    CacheDir(main['M5_BUILD_CACHE'])
980
981if not GetOption('without_python'):
982    # Find Python include and library directories for embedding the
983    # interpreter. We rely on python-config to resolve the appropriate
984    # includes and linker flags. ParseConfig does not seem to understand
985    # the more exotic linker flags such as -Xlinker and -export-dynamic so
986    # we add them explicitly below. If you want to link in an alternate
987    # version of python, see above for instructions on how to invoke
988    # scons with the appropriate PATH set.
989    #
990    # First we check if python2-config exists, else we use python-config
991    python_config = readCommand(['which', 'python2-config'],
992                                exception='').strip()
993    if not os.path.exists(python_config):
994        python_config = readCommand(['which', 'python-config'],
995                                    exception='').strip()
996    py_includes = readCommand([python_config, '--includes'],
997                              exception='').split()
998    # Strip the -I from the include folders before adding them to the
999    # CPPPATH
1000    main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
1001
1002    # Read the linker flags and split them into libraries and other link
1003    # flags. The libraries are added later through the call the CheckLib.
1004    py_ld_flags = readCommand([python_config, '--ldflags'],
1005        exception='').split()
1006    py_libs = []
1007    for lib in py_ld_flags:
1008         if not lib.startswith('-l'):
1009             main.Append(LINKFLAGS=[lib])
1010         else:
1011             lib = lib[2:]
1012             if lib not in py_libs:
1013                 py_libs.append(lib)
1014
1015    # verify that this stuff works
1016    if not conf.CheckHeader('Python.h', '<>'):
1017        print "Error: can't find Python.h header in", py_includes
1018        print "Install Python headers (package python-dev on Ubuntu and RedHat)"
1019        Exit(1)
1020
1021    for lib in py_libs:
1022        if not conf.CheckLib(lib):
1023            print "Error: can't find library %s required by python" % lib
1024            Exit(1)
1025
1026# On Solaris you need to use libsocket for socket ops
1027if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
1028   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
1029       print "Can't find library with socket calls (e.g. accept())"
1030       Exit(1)
1031
1032# Check for zlib.  If the check passes, libz will be automatically
1033# added to the LIBS environment variable.
1034if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
1035    print 'Error: did not find needed zlib compression library '\
1036          'and/or zlib.h header file.'
1037    print '       Please install zlib and try again.'
1038    Exit(1)
1039
1040# If we have the protobuf compiler, also make sure we have the
1041# development libraries. If the check passes, libprotobuf will be
1042# automatically added to the LIBS environment variable. After
1043# this, we can use the HAVE_PROTOBUF flag to determine if we have
1044# got both protoc and libprotobuf available.
1045main['HAVE_PROTOBUF'] = main['PROTOC'] and \
1046    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
1047                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
1048
1049# If we have the compiler but not the library, print another warning.
1050if main['PROTOC'] and not main['HAVE_PROTOBUF']:
1051    print termcap.Yellow + termcap.Bold + \
1052        'Warning: did not find protocol buffer library and/or headers.\n' + \
1053    '       Please install libprotobuf-dev for tracing support.' + \
1054    termcap.Normal
1055
1056# Check for librt.
1057have_posix_clock = \
1058    conf.CheckLibWithHeader(None, 'time.h', 'C',
1059                            'clock_nanosleep(0,0,NULL,NULL);') or \
1060    conf.CheckLibWithHeader('rt', 'time.h', 'C',
1061                            'clock_nanosleep(0,0,NULL,NULL);')
1062
1063have_posix_timers = \
1064    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
1065                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
1066
1067if not GetOption('without_tcmalloc'):
1068    if conf.CheckLib('tcmalloc'):
1069        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
1070    elif conf.CheckLib('tcmalloc_minimal'):
1071        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
1072    else:
1073        print termcap.Yellow + termcap.Bold + \
1074              "You can get a 12% performance improvement by "\
1075              "installing tcmalloc (libgoogle-perftools-dev package "\
1076              "on Ubuntu or RedHat)." + termcap.Normal
1077
1078
1079# Detect back trace implementations. The last implementation in the
1080# list will be used by default.
1081backtrace_impls = [ "none" ]
1082
1083if conf.CheckLibWithHeader(None, 'execinfo.h', 'C',
1084                           'backtrace_symbols_fd((void*)0, 0, 0);'):
1085    backtrace_impls.append("glibc")
1086
1087if backtrace_impls[-1] == "none":
1088    default_backtrace_impl = "none"
1089    print termcap.Yellow + termcap.Bold + \
1090        "No suitable back trace implementation found." + \
1091        termcap.Normal
1092
1093if not have_posix_clock:
1094    print "Can't find library for POSIX clocks."
1095
1096# Check for <fenv.h> (C99 FP environment control)
1097have_fenv = conf.CheckHeader('fenv.h', '<>')
1098if not have_fenv:
1099    print "Warning: Header file <fenv.h> not found."
1100    print "         This host has no IEEE FP rounding mode control."
1101
1102# Check if we should enable KVM-based hardware virtualization. The API
1103# we rely on exists since version 2.6.36 of the kernel, but somehow
1104# the KVM_API_VERSION does not reflect the change. We test for one of
1105# the types as a fall back.
1106have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
1107if not have_kvm:
1108    print "Info: Compatible header file <linux/kvm.h> not found, " \
1109        "disabling KVM support."
1110
1111# x86 needs support for xsave. We test for the structure here since we
1112# won't be able to run new tests by the time we know which ISA we're
1113# targeting.
1114have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
1115                                    '#include <linux/kvm.h>') != 0
1116
1117# Check if the requested target ISA is compatible with the host
1118def is_isa_kvm_compatible(isa):
1119    try:
1120        import platform
1121        host_isa = platform.machine()
1122    except:
1123        print "Warning: Failed to determine host ISA."
1124        return False
1125
1126    if not have_posix_timers:
1127        print "Warning: Can not enable KVM, host seems to lack support " \
1128            "for POSIX timers"
1129        return False
1130
1131    if isa == "arm":
1132        return host_isa in ( "armv7l", "aarch64" )
1133    elif isa == "x86":
1134        if host_isa != "x86_64":
1135            return False
1136
1137        if not have_kvm_xsave:
1138            print "KVM on x86 requires xsave support in kernel headers."
1139            return False
1140
1141        return True
1142    else:
1143        return False
1144
1145
1146# Check if the exclude_host attribute is available. We want this to
1147# get accurate instruction counts in KVM.
1148main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1149    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1150
1151
1152######################################################################
1153#
1154# Finish the configuration
1155#
1156main = conf.Finish()
1157
1158######################################################################
1159#
1160# Collect all non-global variables
1161#
1162
1163# Define the universe of supported ISAs
1164all_isa_list = [ ]
1165all_gpu_isa_list = [ ]
1166Export('all_isa_list')
1167Export('all_gpu_isa_list')
1168
1169class CpuModel(object):
1170    '''The CpuModel class encapsulates everything the ISA parser needs to
1171    know about a particular CPU model.'''
1172
1173    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1174    dict = {}
1175
1176    # Constructor.  Automatically adds models to CpuModel.dict.
1177    def __init__(self, name, default=False):
1178        self.name = name           # name of model
1179
1180        # This cpu is enabled by default
1181        self.default = default
1182
1183        # Add self to dict
1184        if name in CpuModel.dict:
1185            raise AttributeError, "CpuModel '%s' already registered" % name
1186        CpuModel.dict[name] = self
1187
1188Export('CpuModel')
1189
1190# Sticky variables get saved in the variables file so they persist from
1191# one invocation to the next (unless overridden, in which case the new
1192# value becomes sticky).
1193sticky_vars = Variables(args=ARGUMENTS)
1194Export('sticky_vars')
1195
1196# Sticky variables that should be exported
1197export_vars = []
1198Export('export_vars')
1199
1200# For Ruby
1201all_protocols = []
1202Export('all_protocols')
1203protocol_dirs = []
1204Export('protocol_dirs')
1205slicc_includes = []
1206Export('slicc_includes')
1207
1208# Walk the tree and execute all SConsopts scripts that wil add to the
1209# above variables
1210if GetOption('verbose'):
1211    print "Reading SConsopts"
1212for bdir in [ base_dir ] + extras_dir_list:
1213    if not isdir(bdir):
1214        print "Error: directory '%s' does not exist" % bdir
1215        Exit(1)
1216    for root, dirs, files in os.walk(bdir):
1217        if 'SConsopts' in files:
1218            if GetOption('verbose'):
1219                print "Reading", joinpath(root, 'SConsopts')
1220            SConscript(joinpath(root, 'SConsopts'))
1221
1222all_isa_list.sort()
1223all_gpu_isa_list.sort()
1224
1225sticky_vars.AddVariables(
1226    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1227    EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
1228    ListVariable('CPU_MODELS', 'CPU models',
1229                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1230                 sorted(CpuModel.dict.keys())),
1231    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1232                 False),
1233    BoolVariable('SS_COMPATIBLE_FP',
1234                 'Make floating-point results compatible with SimpleScalar',
1235                 False),
1236    BoolVariable('USE_SSE2',
1237                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1238                 False),
1239    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1240    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1241    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1242    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1243    BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1244    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1245                  all_protocols),
1246    EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1247                 backtrace_impls[-1], backtrace_impls)
1248    )
1249
1250# These variables get exported to #defines in config/*.hh (see src/SConscript).
1251export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1252                'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'PROTOCOL',
1253                'HAVE_PROTOBUF', 'HAVE_PERF_ATTR_EXCLUDE_HOST']
1254
1255###################################################
1256#
1257# Define a SCons builder for configuration flag headers.
1258#
1259###################################################
1260
1261# This function generates a config header file that #defines the
1262# variable symbol to the current variable setting (0 or 1).  The source
1263# operands are the name of the variable and a Value node containing the
1264# value of the variable.
1265def build_config_file(target, source, env):
1266    (variable, value) = [s.get_contents() for s in source]
1267    f = file(str(target[0]), 'w')
1268    print >> f, '#define', variable, value
1269    f.close()
1270    return None
1271
1272# Combine the two functions into a scons Action object.
1273config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1274
1275# The emitter munges the source & target node lists to reflect what
1276# we're really doing.
1277def config_emitter(target, source, env):
1278    # extract variable name from Builder arg
1279    variable = str(target[0])
1280    # True target is config header file
1281    target = joinpath('config', variable.lower() + '.hh')
1282    val = env[variable]
1283    if isinstance(val, bool):
1284        # Force value to 0/1
1285        val = int(val)
1286    elif isinstance(val, str):
1287        val = '"' + val + '"'
1288
1289    # Sources are variable name & value (packaged in SCons Value nodes)
1290    return ([target], [Value(variable), Value(val)])
1291
1292config_builder = Builder(emitter = config_emitter, action = config_action)
1293
1294main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1295
1296# libelf build is shared across all configs in the build root.
1297main.SConscript('ext/libelf/SConscript',
1298                variant_dir = joinpath(build_root, 'libelf'))
1299
1300# iostream3 build is shared across all configs in the build root.
1301main.SConscript('ext/iostream3/SConscript',
1302                variant_dir = joinpath(build_root, 'iostream3'))
1303
1304# libfdt build is shared across all configs in the build root.
1305main.SConscript('ext/libfdt/SConscript',
1306                variant_dir = joinpath(build_root, 'libfdt'))
1307
1308# fputils build is shared across all configs in the build root.
1309main.SConscript('ext/fputils/SConscript',
1310                variant_dir = joinpath(build_root, 'fputils'))
1311
1312# DRAMSim2 build is shared across all configs in the build root.
1313main.SConscript('ext/dramsim2/SConscript',
1314                variant_dir = joinpath(build_root, 'dramsim2'))
1315
1316# DRAMPower build is shared across all configs in the build root.
1317main.SConscript('ext/drampower/SConscript',
1318                variant_dir = joinpath(build_root, 'drampower'))
1319
1320# nomali build is shared across all configs in the build root.
1321main.SConscript('ext/nomali/SConscript',
1322                variant_dir = joinpath(build_root, 'nomali'))
1323
1324###################################################
1325#
1326# This function is used to set up a directory with switching headers
1327#
1328###################################################
1329
1330main['ALL_ISA_LIST'] = all_isa_list
1331main['ALL_GPU_ISA_LIST'] = all_gpu_isa_list
1332all_isa_deps = {}
1333def make_switching_dir(dname, switch_headers, env):
1334    # Generate the header.  target[0] is the full path of the output
1335    # header to generate.  'source' is a dummy variable, since we get the
1336    # list of ISAs from env['ALL_ISA_LIST'].
1337    def gen_switch_hdr(target, source, env):
1338        fname = str(target[0])
1339        isa = env['TARGET_ISA'].lower()
1340        try:
1341            f = open(fname, 'w')
1342            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1343            f.close()
1344        except IOError:
1345            print "Failed to create %s" % fname
1346            raise
1347
1348    # Build SCons Action object. 'varlist' specifies env vars that this
1349    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1350    # should get re-executed.
1351    switch_hdr_action = MakeAction(gen_switch_hdr,
1352                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1353
1354    # Instantiate actions for each header
1355    for hdr in switch_headers:
1356        env.Command(hdr, [], switch_hdr_action)
1357
1358    isa_target = Dir('.').up().name.lower().replace('_', '-')
1359    env['PHONY_BASE'] = '#'+isa_target
1360    all_isa_deps[isa_target] = None
1361
1362Export('make_switching_dir')
1363
1364def make_gpu_switching_dir(dname, switch_headers, env):
1365    # Generate the header.  target[0] is the full path of the output
1366    # header to generate.  'source' is a dummy variable, since we get the
1367    # list of ISAs from env['ALL_ISA_LIST'].
1368    def gen_switch_hdr(target, source, env):
1369        fname = str(target[0])
1370
1371        isa = env['TARGET_GPU_ISA'].lower()
1372
1373        try:
1374            f = open(fname, 'w')
1375            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1376            f.close()
1377        except IOError:
1378            print "Failed to create %s" % fname
1379            raise
1380
1381    # Build SCons Action object. 'varlist' specifies env vars that this
1382    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1383    # should get re-executed.
1384    switch_hdr_action = MakeAction(gen_switch_hdr,
1385                          Transform("GENERATE"), varlist=['ALL_ISA_GPU_LIST'])
1386
1387    # Instantiate actions for each header
1388    for hdr in switch_headers:
1389        env.Command(hdr, [], switch_hdr_action)
1390
1391Export('make_gpu_switching_dir')
1392
1393# all-isas -> all-deps -> all-environs -> all_targets
1394main.Alias('#all-isas', [])
1395main.Alias('#all-deps', '#all-isas')
1396
1397# Dummy target to ensure all environments are created before telling
1398# SCons what to actually make (the command line arguments).  We attach
1399# them to the dependence graph after the environments are complete.
1400ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1401def environsComplete(target, source, env):
1402    for t in ORIG_BUILD_TARGETS:
1403        main.Depends('#all-targets', t)
1404
1405# Each build/* switching_dir attaches its *-environs target to #all-environs.
1406main.Append(BUILDERS = {'CompleteEnvirons' :
1407                        Builder(action=MakeAction(environsComplete, None))})
1408main.CompleteEnvirons('#all-environs', [])
1409
1410def doNothing(**ignored): pass
1411main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1412
1413# The final target to which all the original targets ultimately get attached.
1414main.Dummy('#all-targets', '#all-environs')
1415BUILD_TARGETS[:] = ['#all-targets']
1416
1417###################################################
1418#
1419# Define build environments for selected configurations.
1420#
1421###################################################
1422
1423for variant_path in variant_paths:
1424    if not GetOption('silent'):
1425        print "Building in", variant_path
1426
1427    # Make a copy of the build-root environment to use for this config.
1428    env = main.Clone()
1429    env['BUILDDIR'] = variant_path
1430
1431    # variant_dir is the tail component of build path, and is used to
1432    # determine the build parameters (e.g., 'ALPHA_SE')
1433    (build_root, variant_dir) = splitpath(variant_path)
1434
1435    # Set env variables according to the build directory config.
1436    sticky_vars.files = []
1437    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1438    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1439    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1440    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1441    if isfile(current_vars_file):
1442        sticky_vars.files.append(current_vars_file)
1443        if not GetOption('silent'):
1444            print "Using saved variables file %s" % current_vars_file
1445    else:
1446        # Build dir-specific variables file doesn't exist.
1447
1448        # Make sure the directory is there so we can create it later
1449        opt_dir = dirname(current_vars_file)
1450        if not isdir(opt_dir):
1451            mkdir(opt_dir)
1452
1453        # Get default build variables from source tree.  Variables are
1454        # normally determined by name of $VARIANT_DIR, but can be
1455        # overridden by '--default=' arg on command line.
1456        default = GetOption('default')
1457        opts_dir = joinpath(main.root.abspath, 'build_opts')
1458        if default:
1459            default_vars_files = [joinpath(build_root, 'variables', default),
1460                                  joinpath(opts_dir, default)]
1461        else:
1462            default_vars_files = [joinpath(opts_dir, variant_dir)]
1463        existing_files = filter(isfile, default_vars_files)
1464        if existing_files:
1465            default_vars_file = existing_files[0]
1466            sticky_vars.files.append(default_vars_file)
1467            print "Variables file %s not found,\n  using defaults in %s" \
1468                  % (current_vars_file, default_vars_file)
1469        else:
1470            print "Error: cannot find variables file %s or " \
1471                  "default file(s) %s" \
1472                  % (current_vars_file, ' or '.join(default_vars_files))
1473            Exit(1)
1474
1475    # Apply current variable settings to env
1476    sticky_vars.Update(env)
1477
1478    help_texts["local_vars"] += \
1479        "Build variables for %s:\n" % variant_dir \
1480                 + sticky_vars.GenerateHelpText(env)
1481
1482    # Process variable settings.
1483
1484    if not have_fenv and env['USE_FENV']:
1485        print "Warning: <fenv.h> not available; " \
1486              "forcing USE_FENV to False in", variant_dir + "."
1487        env['USE_FENV'] = False
1488
1489    if not env['USE_FENV']:
1490        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1491        print "         FP results may deviate slightly from other platforms."
1492
1493    if env['EFENCE']:
1494        env.Append(LIBS=['efence'])
1495
1496    if env['USE_KVM']:
1497        if not have_kvm:
1498            print "Warning: Can not enable KVM, host seems to lack KVM support"
1499            env['USE_KVM'] = False
1500        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1501            print "Info: KVM support disabled due to unsupported host and " \
1502                "target ISA combination"
1503            env['USE_KVM'] = False
1504
1505    # Warn about missing optional functionality
1506    if env['USE_KVM']:
1507        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1508            print "Warning: perf_event headers lack support for the " \
1509                "exclude_host attribute. KVM instruction counts will " \
1510                "be inaccurate."
1511
1512    # Save sticky variable settings back to current variables file
1513    sticky_vars.Save(current_vars_file, env)
1514
1515    if env['USE_SSE2']:
1516        env.Append(CCFLAGS=['-msse2'])
1517
1518    # The src/SConscript file sets up the build rules in 'env' according
1519    # to the configured variables.  It returns a list of environments,
1520    # one for each variant build (debug, opt, etc.)
1521    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1522
1523def pairwise(iterable):
1524    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1525    a, b = itertools.tee(iterable)
1526    b.next()
1527    return itertools.izip(a, b)
1528
1529# Create false dependencies so SCons will parse ISAs, establish
1530# dependencies, and setup the build Environments serially. Either
1531# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1532# greater than 1. It appears to be standard race condition stuff; it
1533# doesn't always fail, but usually, and the behaviors are different.
1534# Every time I tried to remove this, builds would fail in some
1535# creative new way. So, don't do that. You'll want to, though, because
1536# tests/SConscript takes a long time to make its Environments.
1537for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1538    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1539    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1540
1541# base help text
1542Help('''
1543Usage: scons [scons options] [build variables] [target(s)]
1544
1545Extra scons options:
1546%(options)s
1547
1548Global build variables:
1549%(global_vars)s
1550
1551%(local_vars)s
1552''' % help_texts)
1553