SConstruct revision 11450
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")
263gitdir = main.root.Dir(".git")
264
265
266style_message = """
267You're missing the gem5 style hook, which automatically checks your code
268against the gem5 style rules on hg commit and qrefresh commands.  This
269script will now install the hook in your %s.
270Press enter to continue, or ctrl-c to abort: """
271
272mercurial_style_message = style_message % ".hg/hgrc file"
273git_style_message = style_message % ".git/hooks/ directory"
274
275mercurial_style_upgrade_message = """
276Your Mercurial style hooks are not up-to-date. This script will now
277try to automatically update them. A backup of your hgrc will be saved
278in .hg/hgrc.old.
279Press enter to continue, or ctrl-c to abort: """
280
281mercurial_style_hook = """
282# The following lines were automatically added by gem5/SConstruct
283# to provide the gem5 style-checking hooks
284[extensions]
285hgstyle = %s/util/hgstyle.py
286
287[hooks]
288pretxncommit.style = python:hgstyle.check_style
289pre-qrefresh.style = python:hgstyle.check_style
290# End of SConstruct additions
291
292""" % (main.root.abspath)
293
294mercurial_lib_not_found = """
295Mercurial libraries cannot be found, ignoring style hook.  If
296you are a gem5 developer, please fix this and run the style
297hook. It is important.
298"""
299
300# Check for style hook and prompt for installation if it's not there.
301# Skip this if --ignore-style was specified, there's no interactive
302# terminal to prompt, or no recognized revision control system can be
303# found.
304ignore_style = GetOption('ignore_style') or not sys.stdin.isatty()
305
306# Try wire up Mercurial to the style hooks
307if not ignore_style and hgdir.exists():
308    style_hook = True
309    style_hooks = tuple()
310    hgrc = hgdir.File('hgrc')
311    hgrc_old = hgdir.File('hgrc.old')
312    try:
313        from mercurial import ui
314        ui = ui.ui()
315        ui.readconfig(hgrc.abspath)
316        style_hooks = (ui.config('hooks', 'pretxncommit.style', None),
317                       ui.config('hooks', 'pre-qrefresh.style', None))
318        style_hook = all(style_hooks)
319        style_extension = ui.config('extensions', 'style', None)
320    except ImportError:
321        print mercurial_lib_not_found
322
323    if "python:style.check_style" in style_hooks:
324        # Try to upgrade the style hooks
325        print mercurial_style_upgrade_message
326        # continue unless user does ctrl-c/ctrl-d etc.
327        try:
328            raw_input()
329        except:
330            print "Input exception, exiting scons.\n"
331            sys.exit(1)
332        shutil.copyfile(hgrc.abspath, hgrc_old.abspath)
333        re_style_hook = re.compile(r"^([^=#]+)\.style\s*=\s*([^#\s]+).*")
334        re_style_extension = re.compile("style\s*=\s*([^#\s]+).*")
335        old, new = open(hgrc_old.abspath, 'r'), open(hgrc.abspath, 'w')
336        for l in old:
337            m_hook = re_style_hook.match(l)
338            m_ext = re_style_extension.match(l)
339            if m_hook:
340                hook, check = m_hook.groups()
341                if check != "python:style.check_style":
342                    print "Warning: %s.style is using a non-default " \
343                        "checker: %s" % (hook, check)
344                if hook not in ("pretxncommit", "pre-qrefresh"):
345                    print "Warning: Updating unknown style hook: %s" % hook
346
347                l = "%s.style = python:hgstyle.check_style\n" % hook
348            elif m_ext and m_ext.group(1) == style_extension:
349                l = "hgstyle = %s/util/hgstyle.py\n" % main.root.abspath
350
351            new.write(l)
352    elif not style_hook:
353        print mercurial_style_message,
354        # continue unless user does ctrl-c/ctrl-d etc.
355        try:
356            raw_input()
357        except:
358            print "Input exception, exiting scons.\n"
359            sys.exit(1)
360        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
361        print "Adding style hook to", hgrc_path, "\n"
362        try:
363            with open(hgrc_path, 'a') as f:
364                f.write(mercurial_style_hook)
365        except:
366            print "Error updating", hgrc_path
367            sys.exit(1)
368
369# Try to wire up git to the style hooks
370git_pre_commit_hook = gitdir.File("hooks/pre-commit")
371if not ignore_style and gitdir.exists() and not git_pre_commit_hook.exists():
372    git_style_script = File("util/git-pre-commit.py")
373
374    print git_style_message,
375    try:
376        raw_input()
377    except:
378        print "Input exception, exiting scons.\n"
379        sys.exit(1)
380
381    try:
382        rel_style_script = os.path.relpath(
383            git_style_script.get_abspath(),
384            git_pre_commit_hook.Dir(".").get_abspath())
385        os.symlink(rel_style_script, git_pre_commit_hook.get_abspath())
386    except:
387        print "Error updating git pre-commit hook"
388        raise
389        sys.exit(1)
390
391###################################################
392#
393# Figure out which configurations to set up based on the path(s) of
394# the target(s).
395#
396###################################################
397
398# Find default configuration & binary.
399Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
400
401# helper function: find last occurrence of element in list
402def rfind(l, elt, offs = -1):
403    for i in range(len(l)+offs, 0, -1):
404        if l[i] == elt:
405            return i
406    raise ValueError, "element not found"
407
408# Take a list of paths (or SCons Nodes) and return a list with all
409# paths made absolute and ~-expanded.  Paths will be interpreted
410# relative to the launch directory unless a different root is provided
411def makePathListAbsolute(path_list, root=GetLaunchDir()):
412    return [abspath(joinpath(root, expanduser(str(p))))
413            for p in path_list]
414
415# Each target must have 'build' in the interior of the path; the
416# directory below this will determine the build parameters.  For
417# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
418# recognize that ALPHA_SE specifies the configuration because it
419# follow 'build' in the build path.
420
421# The funky assignment to "[:]" is needed to replace the list contents
422# in place rather than reassign the symbol to a new list, which
423# doesn't work (obviously!).
424BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
425
426# Generate a list of the unique build roots and configs that the
427# collected targets reference.
428variant_paths = []
429build_root = None
430for t in BUILD_TARGETS:
431    path_dirs = t.split('/')
432    try:
433        build_top = rfind(path_dirs, 'build', -2)
434    except:
435        print "Error: no non-leaf 'build' dir found on target path", t
436        Exit(1)
437    this_build_root = joinpath('/',*path_dirs[:build_top+1])
438    if not build_root:
439        build_root = this_build_root
440    else:
441        if this_build_root != build_root:
442            print "Error: build targets not under same build root\n"\
443                  "  %s\n  %s" % (build_root, this_build_root)
444            Exit(1)
445    variant_path = joinpath('/',*path_dirs[:build_top+2])
446    if variant_path not in variant_paths:
447        variant_paths.append(variant_path)
448
449# Make sure build_root exists (might not if this is the first build there)
450if not isdir(build_root):
451    mkdir(build_root)
452main['BUILDROOT'] = build_root
453
454Export('main')
455
456main.SConsignFile(joinpath(build_root, "sconsign"))
457
458# Default duplicate option is to use hard links, but this messes up
459# when you use emacs to edit a file in the target dir, as emacs moves
460# file to file~ then copies to file, breaking the link.  Symbolic
461# (soft) links work better.
462main.SetOption('duplicate', 'soft-copy')
463
464#
465# Set up global sticky variables... these are common to an entire build
466# tree (not specific to a particular build like ALPHA_SE)
467#
468
469global_vars_file = joinpath(build_root, 'variables.global')
470
471global_vars = Variables(global_vars_file, args=ARGUMENTS)
472
473global_vars.AddVariables(
474    ('CC', 'C compiler', environ.get('CC', main['CC'])),
475    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
476    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
477    ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
478    ('BATCH', 'Use batch pool for build and tests', False),
479    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
480    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
481    ('EXTRAS', 'Add extra directories to the compilation', '')
482    )
483
484# Update main environment with values from ARGUMENTS & global_vars_file
485global_vars.Update(main)
486help_texts["global_vars"] += global_vars.GenerateHelpText(main)
487
488# Save sticky variable settings back to current variables file
489global_vars.Save(global_vars_file, main)
490
491# Parse EXTRAS variable to build list of all directories where we're
492# look for sources etc.  This list is exported as extras_dir_list.
493base_dir = main.srcdir.abspath
494if main['EXTRAS']:
495    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
496else:
497    extras_dir_list = []
498
499Export('base_dir')
500Export('extras_dir_list')
501
502# the ext directory should be on the #includes path
503main.Append(CPPPATH=[Dir('ext')])
504
505def strip_build_path(path, env):
506    path = str(path)
507    variant_base = env['BUILDROOT'] + os.path.sep
508    if path.startswith(variant_base):
509        path = path[len(variant_base):]
510    elif path.startswith('build/'):
511        path = path[6:]
512    return path
513
514# Generate a string of the form:
515#   common/path/prefix/src1, src2 -> tgt1, tgt2
516# to print while building.
517class Transform(object):
518    # all specific color settings should be here and nowhere else
519    tool_color = termcap.Normal
520    pfx_color = termcap.Yellow
521    srcs_color = termcap.Yellow + termcap.Bold
522    arrow_color = termcap.Blue + termcap.Bold
523    tgts_color = termcap.Yellow + termcap.Bold
524
525    def __init__(self, tool, max_sources=99):
526        self.format = self.tool_color + (" [%8s] " % tool) \
527                      + self.pfx_color + "%s" \
528                      + self.srcs_color + "%s" \
529                      + self.arrow_color + " -> " \
530                      + self.tgts_color + "%s" \
531                      + termcap.Normal
532        self.max_sources = max_sources
533
534    def __call__(self, target, source, env, for_signature=None):
535        # truncate source list according to max_sources param
536        source = source[0:self.max_sources]
537        def strip(f):
538            return strip_build_path(str(f), env)
539        if len(source) > 0:
540            srcs = map(strip, source)
541        else:
542            srcs = ['']
543        tgts = map(strip, target)
544        # surprisingly, os.path.commonprefix is a dumb char-by-char string
545        # operation that has nothing to do with paths.
546        com_pfx = os.path.commonprefix(srcs + tgts)
547        com_pfx_len = len(com_pfx)
548        if com_pfx:
549            # do some cleanup and sanity checking on common prefix
550            if com_pfx[-1] == ".":
551                # prefix matches all but file extension: ok
552                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
553                com_pfx = com_pfx[0:-1]
554            elif com_pfx[-1] == "/":
555                # common prefix is directory path: OK
556                pass
557            else:
558                src0_len = len(srcs[0])
559                tgt0_len = len(tgts[0])
560                if src0_len == com_pfx_len:
561                    # source is a substring of target, OK
562                    pass
563                elif tgt0_len == com_pfx_len:
564                    # target is a substring of source, need to back up to
565                    # avoid empty string on RHS of arrow
566                    sep_idx = com_pfx.rfind(".")
567                    if sep_idx != -1:
568                        com_pfx = com_pfx[0:sep_idx]
569                    else:
570                        com_pfx = ''
571                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
572                    # still splitting at file extension: ok
573                    pass
574                else:
575                    # probably a fluke; ignore it
576                    com_pfx = ''
577        # recalculate length in case com_pfx was modified
578        com_pfx_len = len(com_pfx)
579        def fmt(files):
580            f = map(lambda s: s[com_pfx_len:], files)
581            return ', '.join(f)
582        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
583
584Export('Transform')
585
586# enable the regression script to use the termcap
587main['TERMCAP'] = termcap
588
589if GetOption('verbose'):
590    def MakeAction(action, string, *args, **kwargs):
591        return Action(action, *args, **kwargs)
592else:
593    MakeAction = Action
594    main['CCCOMSTR']        = Transform("CC")
595    main['CXXCOMSTR']       = Transform("CXX")
596    main['ASCOMSTR']        = Transform("AS")
597    main['SWIGCOMSTR']      = Transform("SWIG")
598    main['ARCOMSTR']        = Transform("AR", 0)
599    main['LINKCOMSTR']      = Transform("LINK", 0)
600    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
601    main['M4COMSTR']        = Transform("M4")
602    main['SHCCCOMSTR']      = Transform("SHCC")
603    main['SHCXXCOMSTR']     = Transform("SHCXX")
604Export('MakeAction')
605
606# Initialize the Link-Time Optimization (LTO) flags
607main['LTO_CCFLAGS'] = []
608main['LTO_LDFLAGS'] = []
609
610# According to the readme, tcmalloc works best if the compiler doesn't
611# assume that we're using the builtin malloc and friends. These flags
612# are compiler-specific, so we need to set them after we detect which
613# compiler we're using.
614main['TCMALLOC_CCFLAGS'] = []
615
616CXX_version = readCommand([main['CXX'],'--version'], exception=False)
617CXX_V = readCommand([main['CXX'],'-V'], exception=False)
618
619main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
620main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
621if main['GCC'] + main['CLANG'] > 1:
622    print 'Error: How can we have two at the same time?'
623    Exit(1)
624
625# Set up default C++ compiler flags
626if main['GCC'] or main['CLANG']:
627    # As gcc and clang share many flags, do the common parts here
628    main.Append(CCFLAGS=['-pipe'])
629    main.Append(CCFLAGS=['-fno-strict-aliasing'])
630    # Enable -Wall and -Wextra and then disable the few warnings that
631    # we consistently violate
632    main.Append(CCFLAGS=['-Wall', '-Wundef', '-Wextra',
633                         '-Wno-sign-compare', '-Wno-unused-parameter'])
634    # We always compile using C++11
635    main.Append(CXXFLAGS=['-std=c++11'])
636else:
637    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
638    print "Don't know what compiler options to use for your compiler."
639    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
640    print termcap.Yellow + '       version:' + termcap.Normal,
641    if not CXX_version:
642        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
643               termcap.Normal
644    else:
645        print CXX_version.replace('\n', '<nl>')
646    print "       If you're trying to use a compiler other than GCC"
647    print "       or clang, there appears to be something wrong with your"
648    print "       environment."
649    print "       "
650    print "       If you are trying to use a compiler other than those listed"
651    print "       above you will need to ease fix SConstruct and "
652    print "       src/SConscript to support that compiler."
653    Exit(1)
654
655if main['GCC']:
656    # Check for a supported version of gcc. >= 4.7 is chosen for its
657    # level of c++11 support. See
658    # http://gcc.gnu.org/projects/cxx0x.html for details.
659    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
660    if compareVersions(gcc_version, "4.7") < 0:
661        print 'Error: gcc version 4.7 or newer required.'
662        print '       Installed version:', gcc_version
663        Exit(1)
664
665    main['GCC_VERSION'] = gcc_version
666
667    # gcc from version 4.8 and above generates "rep; ret" instructions
668    # to avoid performance penalties on certain AMD chips. Older
669    # assemblers detect this as an error, "Error: expecting string
670    # instruction after `rep'"
671    if compareVersions(gcc_version, "4.8") > 0:
672        as_version_raw = readCommand([main['AS'], '-v', '/dev/null'],
673                                     exception=False).split()
674
675        # version strings may contain extra distro-specific
676        # qualifiers, so play it safe and keep only what comes before
677        # the first hyphen
678        as_version = as_version_raw[-1].split('-')[0] if as_version_raw \
679            else None
680
681        if not as_version or compareVersions(as_version, "2.23") < 0:
682            print termcap.Yellow + termcap.Bold + \
683                'Warning: This combination of gcc and binutils have' + \
684                ' known incompatibilities.\n' + \
685                '         If you encounter build problems, please update ' + \
686                'binutils to 2.23.' + \
687                termcap.Normal
688
689    # Make sure we warn if the user has requested to compile with the
690    # Undefined Benahvior Sanitizer and this version of gcc does not
691    # support it.
692    if GetOption('with_ubsan') and \
693            compareVersions(gcc_version, '4.9') < 0:
694        print termcap.Yellow + termcap.Bold + \
695            'Warning: UBSan is only supported using gcc 4.9 and later.' + \
696            termcap.Normal
697
698    # Add the appropriate Link-Time Optimization (LTO) flags
699    # unless LTO is explicitly turned off. Note that these flags
700    # are only used by the fast target.
701    if not GetOption('no_lto'):
702        # Pass the LTO flag when compiling to produce GIMPLE
703        # output, we merely create the flags here and only append
704        # them later
705        main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
706
707        # Use the same amount of jobs for LTO as we are running
708        # scons with
709        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
710
711    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
712                                  '-fno-builtin-realloc', '-fno-builtin-free'])
713
714elif main['CLANG']:
715    # Check for a supported version of clang, >= 3.1 is needed to
716    # support similar features as gcc 4.7. See
717    # http://clang.llvm.org/cxx_status.html for details
718    clang_version_re = re.compile(".* version (\d+\.\d+)")
719    clang_version_match = clang_version_re.search(CXX_version)
720    if (clang_version_match):
721        clang_version = clang_version_match.groups()[0]
722        if compareVersions(clang_version, "3.1") < 0:
723            print 'Error: clang version 3.1 or newer required.'
724            print '       Installed version:', clang_version
725            Exit(1)
726    else:
727        print 'Error: Unable to determine clang version.'
728        Exit(1)
729
730    # clang has a few additional warnings that we disable, extraneous
731    # parantheses are allowed due to Ruby's printing of the AST,
732    # finally self assignments are allowed as the generated CPU code
733    # is relying on this
734    main.Append(CCFLAGS=['-Wno-parentheses',
735                         '-Wno-self-assign',
736                         # Some versions of libstdc++ (4.8?) seem to
737                         # use struct hash and class hash
738                         # interchangeably.
739                         '-Wno-mismatched-tags',
740                         ])
741
742    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
743
744    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
745    # opposed to libstdc++, as the later is dated.
746    if sys.platform == "darwin":
747        main.Append(CXXFLAGS=['-stdlib=libc++'])
748        main.Append(LIBS=['c++'])
749
750else:
751    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
752    print "Don't know what compiler options to use for your compiler."
753    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
754    print termcap.Yellow + '       version:' + termcap.Normal,
755    if not CXX_version:
756        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
757               termcap.Normal
758    else:
759        print CXX_version.replace('\n', '<nl>')
760    print "       If you're trying to use a compiler other than GCC"
761    print "       or clang, there appears to be something wrong with your"
762    print "       environment."
763    print "       "
764    print "       If you are trying to use a compiler other than those listed"
765    print "       above you will need to ease fix SConstruct and "
766    print "       src/SConscript to support that compiler."
767    Exit(1)
768
769# Set up common yacc/bison flags (needed for Ruby)
770main['YACCFLAGS'] = '-d'
771main['YACCHXXFILESUFFIX'] = '.hh'
772
773# Do this after we save setting back, or else we'll tack on an
774# extra 'qdo' every time we run scons.
775if main['BATCH']:
776    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
777    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
778    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
779    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
780    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
781
782if sys.platform == 'cygwin':
783    # cygwin has some header file issues...
784    main.Append(CCFLAGS=["-Wno-uninitialized"])
785
786# Check for the protobuf compiler
787protoc_version = readCommand([main['PROTOC'], '--version'],
788                             exception='').split()
789
790# First two words should be "libprotoc x.y.z"
791if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
792    print termcap.Yellow + termcap.Bold + \
793        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
794        '         Please install protobuf-compiler for tracing support.' + \
795        termcap.Normal
796    main['PROTOC'] = False
797else:
798    # Based on the availability of the compress stream wrappers,
799    # require 2.1.0
800    min_protoc_version = '2.1.0'
801    if compareVersions(protoc_version[1], min_protoc_version) < 0:
802        print termcap.Yellow + termcap.Bold + \
803            'Warning: protoc version', min_protoc_version, \
804            'or newer required.\n' + \
805            '         Installed version:', protoc_version[1], \
806            termcap.Normal
807        main['PROTOC'] = False
808    else:
809        # Attempt to determine the appropriate include path and
810        # library path using pkg-config, that means we also need to
811        # check for pkg-config. Note that it is possible to use
812        # protobuf without the involvement of pkg-config. Later on we
813        # check go a library config check and at that point the test
814        # will fail if libprotobuf cannot be found.
815        if readCommand(['pkg-config', '--version'], exception=''):
816            try:
817                # Attempt to establish what linking flags to add for protobuf
818                # using pkg-config
819                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
820            except:
821                print termcap.Yellow + termcap.Bold + \
822                    'Warning: pkg-config could not get protobuf flags.' + \
823                    termcap.Normal
824
825# Check for SWIG
826if not main.has_key('SWIG'):
827    print 'Error: SWIG utility not found.'
828    print '       Please install (see http://www.swig.org) and retry.'
829    Exit(1)
830
831# Check for appropriate SWIG version
832swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
833# First 3 words should be "SWIG Version x.y.z"
834if len(swig_version) < 3 or \
835        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
836    print 'Error determining SWIG version.'
837    Exit(1)
838
839min_swig_version = '2.0.4'
840if compareVersions(swig_version[2], min_swig_version) < 0:
841    print 'Error: SWIG version', min_swig_version, 'or newer required.'
842    print '       Installed version:', swig_version[2]
843    Exit(1)
844
845# Check for known incompatibilities. The standard library shipped with
846# gcc >= 4.9 does not play well with swig versions prior to 3.0
847if main['GCC'] and compareVersions(gcc_version, '4.9') >= 0 and \
848        compareVersions(swig_version[2], '3.0') < 0:
849    print termcap.Yellow + termcap.Bold + \
850        'Warning: This combination of gcc and swig have' + \
851        ' known incompatibilities.\n' + \
852        '         If you encounter build problems, please update ' + \
853        'swig to 3.0 or later.' + \
854        termcap.Normal
855
856# Set up SWIG flags & scanner
857swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
858main.Append(SWIGFLAGS=swig_flags)
859
860# Check for 'timeout' from GNU coreutils. If present, regressions will
861# be run with a time limit. We require version 8.13 since we rely on
862# support for the '--foreground' option.
863timeout_lines = readCommand(['timeout', '--version'],
864                            exception='').splitlines()
865# Get the first line and tokenize it
866timeout_version = timeout_lines[0].split() if timeout_lines else []
867main['TIMEOUT'] =  timeout_version and \
868    compareVersions(timeout_version[-1], '8.13') >= 0
869
870# filter out all existing swig scanners, they mess up the dependency
871# stuff for some reason
872scanners = []
873for scanner in main['SCANNERS']:
874    skeys = scanner.skeys
875    if skeys == '.i':
876        continue
877
878    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
879        continue
880
881    scanners.append(scanner)
882
883# add the new swig scanner that we like better
884from SCons.Scanner import ClassicCPP as CPPScanner
885swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
886scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
887
888# replace the scanners list that has what we want
889main['SCANNERS'] = scanners
890
891# Add a custom Check function to test for structure members.
892def CheckMember(context, include, decl, member, include_quotes="<>"):
893    context.Message("Checking for member %s in %s..." %
894                    (member, decl))
895    text = """
896#include %(header)s
897int main(){
898  %(decl)s test;
899  (void)test.%(member)s;
900  return 0;
901};
902""" % { "header" : include_quotes[0] + include + include_quotes[1],
903        "decl" : decl,
904        "member" : member,
905        }
906
907    ret = context.TryCompile(text, extension=".cc")
908    context.Result(ret)
909    return ret
910
911# Platform-specific configuration.  Note again that we assume that all
912# builds under a given build root run on the same host platform.
913conf = Configure(main,
914                 conf_dir = joinpath(build_root, '.scons_config'),
915                 log_file = joinpath(build_root, 'scons_config.log'),
916                 custom_tests = {
917        'CheckMember' : CheckMember,
918        })
919
920# Check if we should compile a 64 bit binary on Mac OS X/Darwin
921try:
922    import platform
923    uname = platform.uname()
924    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
925        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
926            main.Append(CCFLAGS=['-arch', 'x86_64'])
927            main.Append(CFLAGS=['-arch', 'x86_64'])
928            main.Append(LINKFLAGS=['-arch', 'x86_64'])
929            main.Append(ASFLAGS=['-arch', 'x86_64'])
930except:
931    pass
932
933# Recent versions of scons substitute a "Null" object for Configure()
934# when configuration isn't necessary, e.g., if the "--help" option is
935# present.  Unfortuantely this Null object always returns false,
936# breaking all our configuration checks.  We replace it with our own
937# more optimistic null object that returns True instead.
938if not conf:
939    def NullCheck(*args, **kwargs):
940        return True
941
942    class NullConf:
943        def __init__(self, env):
944            self.env = env
945        def Finish(self):
946            return self.env
947        def __getattr__(self, mname):
948            return NullCheck
949
950    conf = NullConf(main)
951
952# Cache build files in the supplied directory.
953if main['M5_BUILD_CACHE']:
954    print 'Using build cache located at', main['M5_BUILD_CACHE']
955    CacheDir(main['M5_BUILD_CACHE'])
956
957if not GetOption('without_python'):
958    # Find Python include and library directories for embedding the
959    # interpreter. We rely on python-config to resolve the appropriate
960    # includes and linker flags. ParseConfig does not seem to understand
961    # the more exotic linker flags such as -Xlinker and -export-dynamic so
962    # we add them explicitly below. If you want to link in an alternate
963    # version of python, see above for instructions on how to invoke
964    # scons with the appropriate PATH set.
965    #
966    # First we check if python2-config exists, else we use python-config
967    python_config = readCommand(['which', 'python2-config'],
968                                exception='').strip()
969    if not os.path.exists(python_config):
970        python_config = readCommand(['which', 'python-config'],
971                                    exception='').strip()
972    py_includes = readCommand([python_config, '--includes'],
973                              exception='').split()
974    # Strip the -I from the include folders before adding them to the
975    # CPPPATH
976    main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
977
978    # Read the linker flags and split them into libraries and other link
979    # flags. The libraries are added later through the call the CheckLib.
980    py_ld_flags = readCommand([python_config, '--ldflags'],
981        exception='').split()
982    py_libs = []
983    for lib in py_ld_flags:
984         if not lib.startswith('-l'):
985             main.Append(LINKFLAGS=[lib])
986         else:
987             lib = lib[2:]
988             if lib not in py_libs:
989                 py_libs.append(lib)
990
991    # verify that this stuff works
992    if not conf.CheckHeader('Python.h', '<>'):
993        print "Error: can't find Python.h header in", py_includes
994        print "Install Python headers (package python-dev on Ubuntu and RedHat)"
995        Exit(1)
996
997    for lib in py_libs:
998        if not conf.CheckLib(lib):
999            print "Error: can't find library %s required by python" % lib
1000            Exit(1)
1001
1002# On Solaris you need to use libsocket for socket ops
1003if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
1004   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
1005       print "Can't find library with socket calls (e.g. accept())"
1006       Exit(1)
1007
1008# Check for zlib.  If the check passes, libz will be automatically
1009# added to the LIBS environment variable.
1010if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
1011    print 'Error: did not find needed zlib compression library '\
1012          'and/or zlib.h header file.'
1013    print '       Please install zlib and try again.'
1014    Exit(1)
1015
1016# If we have the protobuf compiler, also make sure we have the
1017# development libraries. If the check passes, libprotobuf will be
1018# automatically added to the LIBS environment variable. After
1019# this, we can use the HAVE_PROTOBUF flag to determine if we have
1020# got both protoc and libprotobuf available.
1021main['HAVE_PROTOBUF'] = main['PROTOC'] and \
1022    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
1023                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
1024
1025# If we have the compiler but not the library, print another warning.
1026if main['PROTOC'] and not main['HAVE_PROTOBUF']:
1027    print termcap.Yellow + termcap.Bold + \
1028        'Warning: did not find protocol buffer library and/or headers.\n' + \
1029    '       Please install libprotobuf-dev for tracing support.' + \
1030    termcap.Normal
1031
1032# Check for librt.
1033have_posix_clock = \
1034    conf.CheckLibWithHeader(None, 'time.h', 'C',
1035                            'clock_nanosleep(0,0,NULL,NULL);') or \
1036    conf.CheckLibWithHeader('rt', 'time.h', 'C',
1037                            'clock_nanosleep(0,0,NULL,NULL);')
1038
1039have_posix_timers = \
1040    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
1041                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
1042
1043if not GetOption('without_tcmalloc'):
1044    if conf.CheckLib('tcmalloc'):
1045        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
1046    elif conf.CheckLib('tcmalloc_minimal'):
1047        main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
1048    else:
1049        print termcap.Yellow + termcap.Bold + \
1050              "You can get a 12% performance improvement by "\
1051              "installing tcmalloc (libgoogle-perftools-dev package "\
1052              "on Ubuntu or RedHat)." + termcap.Normal
1053
1054
1055# Detect back trace implementations. The last implementation in the
1056# list will be used by default.
1057backtrace_impls = [ "none" ]
1058
1059if conf.CheckLibWithHeader(None, 'execinfo.h', 'C',
1060                           'backtrace_symbols_fd((void*)0, 0, 0);'):
1061    backtrace_impls.append("glibc")
1062
1063if backtrace_impls[-1] == "none":
1064    default_backtrace_impl = "none"
1065    print termcap.Yellow + termcap.Bold + \
1066        "No suitable back trace implementation found." + \
1067        termcap.Normal
1068
1069if not have_posix_clock:
1070    print "Can't find library for POSIX clocks."
1071
1072# Check for <fenv.h> (C99 FP environment control)
1073have_fenv = conf.CheckHeader('fenv.h', '<>')
1074if not have_fenv:
1075    print "Warning: Header file <fenv.h> not found."
1076    print "         This host has no IEEE FP rounding mode control."
1077
1078# Check if we should enable KVM-based hardware virtualization. The API
1079# we rely on exists since version 2.6.36 of the kernel, but somehow
1080# the KVM_API_VERSION does not reflect the change. We test for one of
1081# the types as a fall back.
1082have_kvm = conf.CheckHeader('linux/kvm.h', '<>')
1083if not have_kvm:
1084    print "Info: Compatible header file <linux/kvm.h> not found, " \
1085        "disabling KVM support."
1086
1087# x86 needs support for xsave. We test for the structure here since we
1088# won't be able to run new tests by the time we know which ISA we're
1089# targeting.
1090have_kvm_xsave = conf.CheckTypeSize('struct kvm_xsave',
1091                                    '#include <linux/kvm.h>') != 0
1092
1093# Check if the requested target ISA is compatible with the host
1094def is_isa_kvm_compatible(isa):
1095    try:
1096        import platform
1097        host_isa = platform.machine()
1098    except:
1099        print "Warning: Failed to determine host ISA."
1100        return False
1101
1102    if not have_posix_timers:
1103        print "Warning: Can not enable KVM, host seems to lack support " \
1104            "for POSIX timers"
1105        return False
1106
1107    if isa == "arm":
1108        return host_isa in ( "armv7l", "aarch64" )
1109    elif isa == "x86":
1110        if host_isa != "x86_64":
1111            return False
1112
1113        if not have_kvm_xsave:
1114            print "KVM on x86 requires xsave support in kernel headers."
1115            return False
1116
1117        return True
1118    else:
1119        return False
1120
1121
1122# Check if the exclude_host attribute is available. We want this to
1123# get accurate instruction counts in KVM.
1124main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1125    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1126
1127
1128######################################################################
1129#
1130# Finish the configuration
1131#
1132main = conf.Finish()
1133
1134######################################################################
1135#
1136# Collect all non-global variables
1137#
1138
1139# Define the universe of supported ISAs
1140all_isa_list = [ ]
1141all_gpu_isa_list = [ ]
1142Export('all_isa_list')
1143Export('all_gpu_isa_list')
1144
1145class CpuModel(object):
1146    '''The CpuModel class encapsulates everything the ISA parser needs to
1147    know about a particular CPU model.'''
1148
1149    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1150    dict = {}
1151
1152    # Constructor.  Automatically adds models to CpuModel.dict.
1153    def __init__(self, name, default=False):
1154        self.name = name           # name of model
1155
1156        # This cpu is enabled by default
1157        self.default = default
1158
1159        # Add self to dict
1160        if name in CpuModel.dict:
1161            raise AttributeError, "CpuModel '%s' already registered" % name
1162        CpuModel.dict[name] = self
1163
1164Export('CpuModel')
1165
1166# Sticky variables get saved in the variables file so they persist from
1167# one invocation to the next (unless overridden, in which case the new
1168# value becomes sticky).
1169sticky_vars = Variables(args=ARGUMENTS)
1170Export('sticky_vars')
1171
1172# Sticky variables that should be exported
1173export_vars = []
1174Export('export_vars')
1175
1176# For Ruby
1177all_protocols = []
1178Export('all_protocols')
1179protocol_dirs = []
1180Export('protocol_dirs')
1181slicc_includes = []
1182Export('slicc_includes')
1183
1184# Walk the tree and execute all SConsopts scripts that wil add to the
1185# above variables
1186if GetOption('verbose'):
1187    print "Reading SConsopts"
1188for bdir in [ base_dir ] + extras_dir_list:
1189    if not isdir(bdir):
1190        print "Error: directory '%s' does not exist" % bdir
1191        Exit(1)
1192    for root, dirs, files in os.walk(bdir):
1193        if 'SConsopts' in files:
1194            if GetOption('verbose'):
1195                print "Reading", joinpath(root, 'SConsopts')
1196            SConscript(joinpath(root, 'SConsopts'))
1197
1198all_isa_list.sort()
1199all_gpu_isa_list.sort()
1200
1201sticky_vars.AddVariables(
1202    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1203    EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'hsail', all_gpu_isa_list),
1204    ListVariable('CPU_MODELS', 'CPU models',
1205                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1206                 sorted(CpuModel.dict.keys())),
1207    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1208                 False),
1209    BoolVariable('SS_COMPATIBLE_FP',
1210                 'Make floating-point results compatible with SimpleScalar',
1211                 False),
1212    BoolVariable('USE_SSE2',
1213                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1214                 False),
1215    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1216    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1217    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1218    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1219    BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1220    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1221                  all_protocols),
1222    EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1223                 backtrace_impls[-1], backtrace_impls)
1224    )
1225
1226# These variables get exported to #defines in config/*.hh (see src/SConscript).
1227export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'TARGET_GPU_ISA',
1228                'CP_ANNOTATE', 'USE_POSIX_CLOCK', 'USE_KVM', 'PROTOCOL',
1229                'HAVE_PROTOBUF', 'HAVE_PERF_ATTR_EXCLUDE_HOST']
1230
1231###################################################
1232#
1233# Define a SCons builder for configuration flag headers.
1234#
1235###################################################
1236
1237# This function generates a config header file that #defines the
1238# variable symbol to the current variable setting (0 or 1).  The source
1239# operands are the name of the variable and a Value node containing the
1240# value of the variable.
1241def build_config_file(target, source, env):
1242    (variable, value) = [s.get_contents() for s in source]
1243    f = file(str(target[0]), 'w')
1244    print >> f, '#define', variable, value
1245    f.close()
1246    return None
1247
1248# Combine the two functions into a scons Action object.
1249config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1250
1251# The emitter munges the source & target node lists to reflect what
1252# we're really doing.
1253def config_emitter(target, source, env):
1254    # extract variable name from Builder arg
1255    variable = str(target[0])
1256    # True target is config header file
1257    target = joinpath('config', variable.lower() + '.hh')
1258    val = env[variable]
1259    if isinstance(val, bool):
1260        # Force value to 0/1
1261        val = int(val)
1262    elif isinstance(val, str):
1263        val = '"' + val + '"'
1264
1265    # Sources are variable name & value (packaged in SCons Value nodes)
1266    return ([target], [Value(variable), Value(val)])
1267
1268config_builder = Builder(emitter = config_emitter, action = config_action)
1269
1270main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1271
1272# libelf build is shared across all configs in the build root.
1273main.SConscript('ext/libelf/SConscript',
1274                variant_dir = joinpath(build_root, 'libelf'))
1275
1276# iostream3 build is shared across all configs in the build root.
1277main.SConscript('ext/iostream3/SConscript',
1278                variant_dir = joinpath(build_root, 'iostream3'))
1279
1280# libfdt build is shared across all configs in the build root.
1281main.SConscript('ext/libfdt/SConscript',
1282                variant_dir = joinpath(build_root, 'libfdt'))
1283
1284# fputils build is shared across all configs in the build root.
1285main.SConscript('ext/fputils/SConscript',
1286                variant_dir = joinpath(build_root, 'fputils'))
1287
1288# DRAMSim2 build is shared across all configs in the build root.
1289main.SConscript('ext/dramsim2/SConscript',
1290                variant_dir = joinpath(build_root, 'dramsim2'))
1291
1292# DRAMPower build is shared across all configs in the build root.
1293main.SConscript('ext/drampower/SConscript',
1294                variant_dir = joinpath(build_root, 'drampower'))
1295
1296# nomali build is shared across all configs in the build root.
1297main.SConscript('ext/nomali/SConscript',
1298                variant_dir = joinpath(build_root, 'nomali'))
1299
1300###################################################
1301#
1302# This function is used to set up a directory with switching headers
1303#
1304###################################################
1305
1306main['ALL_ISA_LIST'] = all_isa_list
1307main['ALL_GPU_ISA_LIST'] = all_gpu_isa_list
1308all_isa_deps = {}
1309def make_switching_dir(dname, switch_headers, env):
1310    # Generate the header.  target[0] is the full path of the output
1311    # header to generate.  'source' is a dummy variable, since we get the
1312    # list of ISAs from env['ALL_ISA_LIST'].
1313    def gen_switch_hdr(target, source, env):
1314        fname = str(target[0])
1315        isa = env['TARGET_ISA'].lower()
1316        try:
1317            f = open(fname, 'w')
1318            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1319            f.close()
1320        except IOError:
1321            print "Failed to create %s" % fname
1322            raise
1323
1324    # Build SCons Action object. 'varlist' specifies env vars that this
1325    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1326    # should get re-executed.
1327    switch_hdr_action = MakeAction(gen_switch_hdr,
1328                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1329
1330    # Instantiate actions for each header
1331    for hdr in switch_headers:
1332        env.Command(hdr, [], switch_hdr_action)
1333
1334    isa_target = Dir('.').up().name.lower().replace('_', '-')
1335    env['PHONY_BASE'] = '#'+isa_target
1336    all_isa_deps[isa_target] = None
1337
1338Export('make_switching_dir')
1339
1340def make_gpu_switching_dir(dname, switch_headers, env):
1341    # Generate the header.  target[0] is the full path of the output
1342    # header to generate.  'source' is a dummy variable, since we get the
1343    # list of ISAs from env['ALL_ISA_LIST'].
1344    def gen_switch_hdr(target, source, env):
1345        fname = str(target[0])
1346
1347        isa = env['TARGET_GPU_ISA'].lower()
1348
1349        try:
1350            f = open(fname, 'w')
1351            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1352            f.close()
1353        except IOError:
1354            print "Failed to create %s" % fname
1355            raise
1356
1357    # Build SCons Action object. 'varlist' specifies env vars that this
1358    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1359    # should get re-executed.
1360    switch_hdr_action = MakeAction(gen_switch_hdr,
1361                          Transform("GENERATE"), varlist=['ALL_ISA_GPU_LIST'])
1362
1363    # Instantiate actions for each header
1364    for hdr in switch_headers:
1365        env.Command(hdr, [], switch_hdr_action)
1366
1367Export('make_gpu_switching_dir')
1368
1369# all-isas -> all-deps -> all-environs -> all_targets
1370main.Alias('#all-isas', [])
1371main.Alias('#all-deps', '#all-isas')
1372
1373# Dummy target to ensure all environments are created before telling
1374# SCons what to actually make (the command line arguments).  We attach
1375# them to the dependence graph after the environments are complete.
1376ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1377def environsComplete(target, source, env):
1378    for t in ORIG_BUILD_TARGETS:
1379        main.Depends('#all-targets', t)
1380
1381# Each build/* switching_dir attaches its *-environs target to #all-environs.
1382main.Append(BUILDERS = {'CompleteEnvirons' :
1383                        Builder(action=MakeAction(environsComplete, None))})
1384main.CompleteEnvirons('#all-environs', [])
1385
1386def doNothing(**ignored): pass
1387main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1388
1389# The final target to which all the original targets ultimately get attached.
1390main.Dummy('#all-targets', '#all-environs')
1391BUILD_TARGETS[:] = ['#all-targets']
1392
1393###################################################
1394#
1395# Define build environments for selected configurations.
1396#
1397###################################################
1398
1399for variant_path in variant_paths:
1400    if not GetOption('silent'):
1401        print "Building in", variant_path
1402
1403    # Make a copy of the build-root environment to use for this config.
1404    env = main.Clone()
1405    env['BUILDDIR'] = variant_path
1406
1407    # variant_dir is the tail component of build path, and is used to
1408    # determine the build parameters (e.g., 'ALPHA_SE')
1409    (build_root, variant_dir) = splitpath(variant_path)
1410
1411    # Set env variables according to the build directory config.
1412    sticky_vars.files = []
1413    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1414    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1415    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1416    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1417    if isfile(current_vars_file):
1418        sticky_vars.files.append(current_vars_file)
1419        if not GetOption('silent'):
1420            print "Using saved variables file %s" % current_vars_file
1421    else:
1422        # Build dir-specific variables file doesn't exist.
1423
1424        # Make sure the directory is there so we can create it later
1425        opt_dir = dirname(current_vars_file)
1426        if not isdir(opt_dir):
1427            mkdir(opt_dir)
1428
1429        # Get default build variables from source tree.  Variables are
1430        # normally determined by name of $VARIANT_DIR, but can be
1431        # overridden by '--default=' arg on command line.
1432        default = GetOption('default')
1433        opts_dir = joinpath(main.root.abspath, 'build_opts')
1434        if default:
1435            default_vars_files = [joinpath(build_root, 'variables', default),
1436                                  joinpath(opts_dir, default)]
1437        else:
1438            default_vars_files = [joinpath(opts_dir, variant_dir)]
1439        existing_files = filter(isfile, default_vars_files)
1440        if existing_files:
1441            default_vars_file = existing_files[0]
1442            sticky_vars.files.append(default_vars_file)
1443            print "Variables file %s not found,\n  using defaults in %s" \
1444                  % (current_vars_file, default_vars_file)
1445        else:
1446            print "Error: cannot find variables file %s or " \
1447                  "default file(s) %s" \
1448                  % (current_vars_file, ' or '.join(default_vars_files))
1449            Exit(1)
1450
1451    # Apply current variable settings to env
1452    sticky_vars.Update(env)
1453
1454    help_texts["local_vars"] += \
1455        "Build variables for %s:\n" % variant_dir \
1456                 + sticky_vars.GenerateHelpText(env)
1457
1458    # Process variable settings.
1459
1460    if not have_fenv and env['USE_FENV']:
1461        print "Warning: <fenv.h> not available; " \
1462              "forcing USE_FENV to False in", variant_dir + "."
1463        env['USE_FENV'] = False
1464
1465    if not env['USE_FENV']:
1466        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1467        print "         FP results may deviate slightly from other platforms."
1468
1469    if env['EFENCE']:
1470        env.Append(LIBS=['efence'])
1471
1472    if env['USE_KVM']:
1473        if not have_kvm:
1474            print "Warning: Can not enable KVM, host seems to lack KVM support"
1475            env['USE_KVM'] = False
1476        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1477            print "Info: KVM support disabled due to unsupported host and " \
1478                "target ISA combination"
1479            env['USE_KVM'] = False
1480
1481    # Warn about missing optional functionality
1482    if env['USE_KVM']:
1483        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1484            print "Warning: perf_event headers lack support for the " \
1485                "exclude_host attribute. KVM instruction counts will " \
1486                "be inaccurate."
1487
1488    # Save sticky variable settings back to current variables file
1489    sticky_vars.Save(current_vars_file, env)
1490
1491    if env['USE_SSE2']:
1492        env.Append(CCFLAGS=['-msse2'])
1493
1494    # The src/SConscript file sets up the build rules in 'env' according
1495    # to the configured variables.  It returns a list of environments,
1496    # one for each variant build (debug, opt, etc.)
1497    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1498
1499def pairwise(iterable):
1500    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1501    a, b = itertools.tee(iterable)
1502    b.next()
1503    return itertools.izip(a, b)
1504
1505# Create false dependencies so SCons will parse ISAs, establish
1506# dependencies, and setup the build Environments serially. Either
1507# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1508# greater than 1. It appears to be standard race condition stuff; it
1509# doesn't always fail, but usually, and the behaviors are different.
1510# Every time I tried to remove this, builds would fail in some
1511# creative new way. So, don't do that. You'll want to, though, because
1512# tests/SConscript takes a long time to make its Environments.
1513for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1514    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1515    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1516
1517# base help text
1518Help('''
1519Usage: scons [scons options] [build variables] [target(s)]
1520
1521Extra scons options:
1522%(options)s
1523
1524Global build variables:
1525%(global_vars)s
1526
1527%(local_vars)s
1528''' % help_texts)
1529