SConstruct revision 10384
1# -*- mode:python -*-
2
3# Copyright (c) 2013 ARM Limited
4# All rights reserved.
5#
6# The license below extends only to copyright in the software and shall
7# not be construed as granting a license to any other intellectual
8# property including but not limited to intellectual property relating
9# to a hardware implementation of the functionality of the software
10# licensed hereunder.  You may use the software subject to the license
11# terms below provided that you ensure that this notice is replicated
12# unmodified and in its entirety in all distributions of the software,
13# modified or unmodified, in source code or in binary form.
14#
15# Copyright (c) 2011 Advanced Micro Devices, Inc.
16# Copyright (c) 2009 The Hewlett-Packard Development Company
17# Copyright (c) 2004-2005 The Regents of The University of Michigan
18# All rights reserved.
19#
20# Redistribution and use in source and binary forms, with or without
21# modification, are permitted provided that the following conditions are
22# met: redistributions of source code must retain the above copyright
23# notice, this list of conditions and the following disclaimer;
24# redistributions in binary form must reproduce the above copyright
25# notice, this list of conditions and the following disclaimer in the
26# documentation and/or other materials provided with the distribution;
27# neither the name of the copyright holders nor the names of its
28# contributors may be used to endorse or promote products derived from
29# this software without specific prior written permission.
30#
31# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42#
43# Authors: Steve Reinhardt
44#          Nathan Binkert
45
46###################################################
47#
48# SCons top-level build description (SConstruct) file.
49#
50# While in this directory ('gem5'), just type 'scons' to build the default
51# configuration (see below), or type 'scons build/<CONFIG>/<binary>'
52# to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
53# the optimized full-system version).
54#
55# You can build gem5 in a different directory as long as there is a
56# 'build/<CONFIG>' somewhere along the target path.  The build system
57# expects that all configs under the same build directory are being
58# built for the same host system.
59#
60# Examples:
61#
62#   The following two commands are equivalent.  The '-u' option tells
63#   scons to search up the directory tree for this SConstruct file.
64#   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
65#   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
66#
67#   The following two commands are equivalent and demonstrate building
68#   in a directory outside of the source tree.  The '-C' option tells
69#   scons to chdir to the specified directory to find this SConstruct
70#   file.
71#   % cd <path-to-src>/gem5 ; scons /local/foo/build/ALPHA/gem5.debug
72#   % cd /local/foo/build/ALPHA; scons -C <path-to-src>/gem5 gem5.debug
73#
74# You can use 'scons -H' to print scons options.  If you're in this
75# 'gem5' directory (or use -u or -C to tell scons where to find this
76# file), you can use 'scons -h' to print all the gem5-specific build
77# options as well.
78#
79###################################################
80
81# Check for recent-enough Python and SCons versions.
82try:
83    # Really old versions of scons only take two options for the
84    # function, so check once without the revision and once with the
85    # revision, the first instance will fail for stuff other than
86    # 0.98, and the second will fail for 0.98.0
87    EnsureSConsVersion(0, 98)
88    EnsureSConsVersion(0, 98, 1)
89except SystemExit, e:
90    print """
91For more details, see:
92    http://gem5.org/Dependencies
93"""
94    raise
95
96# We ensure the python version early because because python-config
97# requires python 2.5
98try:
99    EnsurePythonVersion(2, 5)
100except SystemExit, e:
101    print """
102You can use a non-default installation of the Python interpreter by
103rearranging your PATH so that scons finds the non-default 'python' and
104'python-config' first.
105
106For more details, see:
107    http://gem5.org/wiki/index.php/Using_a_non-default_Python_installation
108"""
109    raise
110
111# Global Python includes
112import itertools
113import os
114import re
115import subprocess
116import sys
117
118from os import mkdir, environ
119from os.path import abspath, basename, dirname, expanduser, normpath
120from os.path import exists,  isdir, isfile
121from os.path import join as joinpath, split as splitpath
122
123# SCons includes
124import SCons
125import SCons.Node
126
127extra_python_paths = [
128    Dir('src/python').srcnode().abspath, # gem5 includes
129    Dir('ext/ply').srcnode().abspath, # ply is used by several files
130    ]
131
132sys.path[1:1] = extra_python_paths
133
134from m5.util import compareVersions, readCommand
135from m5.util.terminal import get_termcap
136
137help_texts = {
138    "options" : "",
139    "global_vars" : "",
140    "local_vars" : ""
141}
142
143Export("help_texts")
144
145
146# There's a bug in scons in that (1) by default, the help texts from
147# AddOption() are supposed to be displayed when you type 'scons -h'
148# and (2) you can override the help displayed by 'scons -h' using the
149# Help() function, but these two features are incompatible: once
150# you've overridden the help text using Help(), there's no way to get
151# at the help texts from AddOptions.  See:
152#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
153#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
154# This hack lets us extract the help text from AddOptions and
155# re-inject it via Help().  Ideally someday this bug will be fixed and
156# we can just use AddOption directly.
157def AddLocalOption(*args, **kwargs):
158    col_width = 30
159
160    help = "  " + ", ".join(args)
161    if "help" in kwargs:
162        length = len(help)
163        if length >= col_width:
164            help += "\n" + " " * col_width
165        else:
166            help += " " * (col_width - length)
167        help += kwargs["help"]
168    help_texts["options"] += help + "\n"
169
170    AddOption(*args, **kwargs)
171
172AddLocalOption('--colors', dest='use_colors', action='store_true',
173               help="Add color to abbreviated scons output")
174AddLocalOption('--no-colors', dest='use_colors', action='store_false',
175               help="Don't add color to abbreviated scons output")
176AddLocalOption('--default', dest='default', type='string', action='store',
177               help='Override which build_opts file to use for defaults')
178AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
179               help='Disable style checking hooks')
180AddLocalOption('--no-lto', dest='no_lto', action='store_true',
181               help='Disable Link-Time Optimization for fast')
182AddLocalOption('--update-ref', dest='update_ref', action='store_true',
183               help='Update test reference outputs')
184AddLocalOption('--verbose', dest='verbose', action='store_true',
185               help='Print full tool command lines')
186
187termcap = get_termcap(GetOption('use_colors'))
188
189########################################################################
190#
191# Set up the main build environment.
192#
193########################################################################
194
195# export TERM so that clang reports errors in color
196use_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH',
197                 'LIBRARY_PATH', 'PATH', 'PKG_CONFIG_PATH', 'PROTOC',
198                 'PYTHONPATH', 'RANLIB', 'SWIG', 'TERM' ])
199
200use_prefixes = [
201    "M5",           # M5 configuration (e.g., path to kernels)
202    "DISTCC_",      # distcc (distributed compiler wrapper) configuration
203    "CCACHE_",      # ccache (caching compiler wrapper) configuration
204    "CCC_",         # clang static analyzer configuration
205    ]
206
207use_env = {}
208for key,val in os.environ.iteritems():
209    if key in use_vars or \
210            any([key.startswith(prefix) for prefix in use_prefixes]):
211        use_env[key] = val
212
213main = Environment(ENV=use_env)
214main.Decider('MD5-timestamp')
215main.root = Dir(".")         # The current directory (where this file lives).
216main.srcdir = Dir("src")     # The source directory
217
218main_dict_keys = main.Dictionary().keys()
219
220# Check that we have a C/C++ compiler
221if not ('CC' in main_dict_keys and 'CXX' in main_dict_keys):
222    print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
223    Exit(1)
224
225# Check that swig is present
226if not 'SWIG' in main_dict_keys:
227    print "swig is not installed (package swig on Ubuntu and RedHat)"
228    Exit(1)
229
230# add useful python code PYTHONPATH so it can be used by subprocesses
231# as well
232main.AppendENVPath('PYTHONPATH', extra_python_paths)
233
234########################################################################
235#
236# Mercurial Stuff.
237#
238# If the gem5 directory is a mercurial repository, we should do some
239# extra things.
240#
241########################################################################
242
243hgdir = main.root.Dir(".hg")
244
245mercurial_style_message = """
246You're missing the gem5 style hook, which automatically checks your code
247against the gem5 style rules on hg commit and qrefresh commands.  This
248script will now install the hook in your .hg/hgrc file.
249Press enter to continue, or ctrl-c to abort: """
250
251mercurial_style_hook = """
252# The following lines were automatically added by gem5/SConstruct
253# to provide the gem5 style-checking hooks
254[extensions]
255style = %s/util/style.py
256
257[hooks]
258pretxncommit.style = python:style.check_style
259pre-qrefresh.style = python:style.check_style
260# End of SConstruct additions
261
262""" % (main.root.abspath)
263
264mercurial_lib_not_found = """
265Mercurial libraries cannot be found, ignoring style hook.  If
266you are a gem5 developer, please fix this and run the style
267hook. It is important.
268"""
269
270# Check for style hook and prompt for installation if it's not there.
271# Skip this if --ignore-style was specified, there's no .hg dir to
272# install a hook in, or there's no interactive terminal to prompt.
273if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
274    style_hook = True
275    try:
276        from mercurial import ui
277        ui = ui.ui()
278        ui.readconfig(hgdir.File('hgrc').abspath)
279        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
280                     ui.config('hooks', 'pre-qrefresh.style', None)
281    except ImportError:
282        print mercurial_lib_not_found
283
284    if not style_hook:
285        print mercurial_style_message,
286        # continue unless user does ctrl-c/ctrl-d etc.
287        try:
288            raw_input()
289        except:
290            print "Input exception, exiting scons.\n"
291            sys.exit(1)
292        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
293        print "Adding style hook to", hgrc_path, "\n"
294        try:
295            hgrc = open(hgrc_path, 'a')
296            hgrc.write(mercurial_style_hook)
297            hgrc.close()
298        except:
299            print "Error updating", hgrc_path
300            sys.exit(1)
301
302
303###################################################
304#
305# Figure out which configurations to set up based on the path(s) of
306# the target(s).
307#
308###################################################
309
310# Find default configuration & binary.
311Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
312
313# helper function: find last occurrence of element in list
314def rfind(l, elt, offs = -1):
315    for i in range(len(l)+offs, 0, -1):
316        if l[i] == elt:
317            return i
318    raise ValueError, "element not found"
319
320# Take a list of paths (or SCons Nodes) and return a list with all
321# paths made absolute and ~-expanded.  Paths will be interpreted
322# relative to the launch directory unless a different root is provided
323def makePathListAbsolute(path_list, root=GetLaunchDir()):
324    return [abspath(joinpath(root, expanduser(str(p))))
325            for p in path_list]
326
327# Each target must have 'build' in the interior of the path; the
328# directory below this will determine the build parameters.  For
329# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
330# recognize that ALPHA_SE specifies the configuration because it
331# follow 'build' in the build path.
332
333# The funky assignment to "[:]" is needed to replace the list contents
334# in place rather than reassign the symbol to a new list, which
335# doesn't work (obviously!).
336BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
337
338# Generate a list of the unique build roots and configs that the
339# collected targets reference.
340variant_paths = []
341build_root = None
342for t in BUILD_TARGETS:
343    path_dirs = t.split('/')
344    try:
345        build_top = rfind(path_dirs, 'build', -2)
346    except:
347        print "Error: no non-leaf 'build' dir found on target path", t
348        Exit(1)
349    this_build_root = joinpath('/',*path_dirs[:build_top+1])
350    if not build_root:
351        build_root = this_build_root
352    else:
353        if this_build_root != build_root:
354            print "Error: build targets not under same build root\n"\
355                  "  %s\n  %s" % (build_root, this_build_root)
356            Exit(1)
357    variant_path = joinpath('/',*path_dirs[:build_top+2])
358    if variant_path not in variant_paths:
359        variant_paths.append(variant_path)
360
361# Make sure build_root exists (might not if this is the first build there)
362if not isdir(build_root):
363    mkdir(build_root)
364main['BUILDROOT'] = build_root
365
366Export('main')
367
368main.SConsignFile(joinpath(build_root, "sconsign"))
369
370# Default duplicate option is to use hard links, but this messes up
371# when you use emacs to edit a file in the target dir, as emacs moves
372# file to file~ then copies to file, breaking the link.  Symbolic
373# (soft) links work better.
374main.SetOption('duplicate', 'soft-copy')
375
376#
377# Set up global sticky variables... these are common to an entire build
378# tree (not specific to a particular build like ALPHA_SE)
379#
380
381global_vars_file = joinpath(build_root, 'variables.global')
382
383global_vars = Variables(global_vars_file, args=ARGUMENTS)
384
385global_vars.AddVariables(
386    ('CC', 'C compiler', environ.get('CC', main['CC'])),
387    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
388    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
389    ('PROTOC', 'protoc tool', environ.get('PROTOC', 'protoc')),
390    ('BATCH', 'Use batch pool for build and tests', False),
391    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
392    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
393    ('EXTRAS', 'Add extra directories to the compilation', '')
394    )
395
396# Update main environment with values from ARGUMENTS & global_vars_file
397global_vars.Update(main)
398help_texts["global_vars"] += global_vars.GenerateHelpText(main)
399
400# Save sticky variable settings back to current variables file
401global_vars.Save(global_vars_file, main)
402
403# Parse EXTRAS variable to build list of all directories where we're
404# look for sources etc.  This list is exported as extras_dir_list.
405base_dir = main.srcdir.abspath
406if main['EXTRAS']:
407    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
408else:
409    extras_dir_list = []
410
411Export('base_dir')
412Export('extras_dir_list')
413
414# the ext directory should be on the #includes path
415main.Append(CPPPATH=[Dir('ext')])
416
417def strip_build_path(path, env):
418    path = str(path)
419    variant_base = env['BUILDROOT'] + os.path.sep
420    if path.startswith(variant_base):
421        path = path[len(variant_base):]
422    elif path.startswith('build/'):
423        path = path[6:]
424    return path
425
426# Generate a string of the form:
427#   common/path/prefix/src1, src2 -> tgt1, tgt2
428# to print while building.
429class Transform(object):
430    # all specific color settings should be here and nowhere else
431    tool_color = termcap.Normal
432    pfx_color = termcap.Yellow
433    srcs_color = termcap.Yellow + termcap.Bold
434    arrow_color = termcap.Blue + termcap.Bold
435    tgts_color = termcap.Yellow + termcap.Bold
436
437    def __init__(self, tool, max_sources=99):
438        self.format = self.tool_color + (" [%8s] " % tool) \
439                      + self.pfx_color + "%s" \
440                      + self.srcs_color + "%s" \
441                      + self.arrow_color + " -> " \
442                      + self.tgts_color + "%s" \
443                      + termcap.Normal
444        self.max_sources = max_sources
445
446    def __call__(self, target, source, env, for_signature=None):
447        # truncate source list according to max_sources param
448        source = source[0:self.max_sources]
449        def strip(f):
450            return strip_build_path(str(f), env)
451        if len(source) > 0:
452            srcs = map(strip, source)
453        else:
454            srcs = ['']
455        tgts = map(strip, target)
456        # surprisingly, os.path.commonprefix is a dumb char-by-char string
457        # operation that has nothing to do with paths.
458        com_pfx = os.path.commonprefix(srcs + tgts)
459        com_pfx_len = len(com_pfx)
460        if com_pfx:
461            # do some cleanup and sanity checking on common prefix
462            if com_pfx[-1] == ".":
463                # prefix matches all but file extension: ok
464                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
465                com_pfx = com_pfx[0:-1]
466            elif com_pfx[-1] == "/":
467                # common prefix is directory path: OK
468                pass
469            else:
470                src0_len = len(srcs[0])
471                tgt0_len = len(tgts[0])
472                if src0_len == com_pfx_len:
473                    # source is a substring of target, OK
474                    pass
475                elif tgt0_len == com_pfx_len:
476                    # target is a substring of source, need to back up to
477                    # avoid empty string on RHS of arrow
478                    sep_idx = com_pfx.rfind(".")
479                    if sep_idx != -1:
480                        com_pfx = com_pfx[0:sep_idx]
481                    else:
482                        com_pfx = ''
483                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
484                    # still splitting at file extension: ok
485                    pass
486                else:
487                    # probably a fluke; ignore it
488                    com_pfx = ''
489        # recalculate length in case com_pfx was modified
490        com_pfx_len = len(com_pfx)
491        def fmt(files):
492            f = map(lambda s: s[com_pfx_len:], files)
493            return ', '.join(f)
494        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
495
496Export('Transform')
497
498# enable the regression script to use the termcap
499main['TERMCAP'] = termcap
500
501if GetOption('verbose'):
502    def MakeAction(action, string, *args, **kwargs):
503        return Action(action, *args, **kwargs)
504else:
505    MakeAction = Action
506    main['CCCOMSTR']        = Transform("CC")
507    main['CXXCOMSTR']       = Transform("CXX")
508    main['ASCOMSTR']        = Transform("AS")
509    main['SWIGCOMSTR']      = Transform("SWIG")
510    main['ARCOMSTR']        = Transform("AR", 0)
511    main['LINKCOMSTR']      = Transform("LINK", 0)
512    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
513    main['M4COMSTR']        = Transform("M4")
514    main['SHCCCOMSTR']      = Transform("SHCC")
515    main['SHCXXCOMSTR']     = Transform("SHCXX")
516Export('MakeAction')
517
518# Initialize the Link-Time Optimization (LTO) flags
519main['LTO_CCFLAGS'] = []
520main['LTO_LDFLAGS'] = []
521
522# According to the readme, tcmalloc works best if the compiler doesn't
523# assume that we're using the builtin malloc and friends. These flags
524# are compiler-specific, so we need to set them after we detect which
525# compiler we're using.
526main['TCMALLOC_CCFLAGS'] = []
527
528CXX_version = readCommand([main['CXX'],'--version'], exception=False)
529CXX_V = readCommand([main['CXX'],'-V'], exception=False)
530
531main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
532main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
533if main['GCC'] + main['CLANG'] > 1:
534    print 'Error: How can we have two at the same time?'
535    Exit(1)
536
537# Set up default C++ compiler flags
538if main['GCC'] or main['CLANG']:
539    # As gcc and clang share many flags, do the common parts here
540    main.Append(CCFLAGS=['-pipe'])
541    main.Append(CCFLAGS=['-fno-strict-aliasing'])
542    # Enable -Wall and then disable the few warnings that we
543    # consistently violate
544    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
545    # We always compile using C++11, but only gcc >= 4.7 and clang 3.1
546    # actually use that name, so we stick with c++0x
547    main.Append(CXXFLAGS=['-std=c++0x'])
548    # Add selected sanity checks from -Wextra
549    main.Append(CXXFLAGS=['-Wmissing-field-initializers',
550                          '-Woverloaded-virtual'])
551else:
552    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
553    print "Don't know what compiler options to use for your compiler."
554    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
555    print termcap.Yellow + '       version:' + termcap.Normal,
556    if not CXX_version:
557        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
558               termcap.Normal
559    else:
560        print CXX_version.replace('\n', '<nl>')
561    print "       If you're trying to use a compiler other than GCC"
562    print "       or clang, there appears to be something wrong with your"
563    print "       environment."
564    print "       "
565    print "       If you are trying to use a compiler other than those listed"
566    print "       above you will need to ease fix SConstruct and "
567    print "       src/SConscript to support that compiler."
568    Exit(1)
569
570if main['GCC']:
571    # Check for a supported version of gcc. >= 4.6 is chosen for its
572    # level of c++11 support. See
573    # http://gcc.gnu.org/projects/cxx0x.html for details. 4.6 is also
574    # the first version with proper LTO support.
575    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
576    if compareVersions(gcc_version, "4.6") < 0:
577        print 'Error: gcc version 4.6 or newer required.'
578        print '       Installed version:', gcc_version
579        Exit(1)
580
581    main['GCC_VERSION'] = gcc_version
582
583    # gcc from version 4.8 and above generates "rep; ret" instructions
584    # to avoid performance penalties on certain AMD chips. Older
585    # assemblers detect this as an error, "Error: expecting string
586    # instruction after `rep'"
587    if compareVersions(gcc_version, "4.8") > 0:
588        as_version = readCommand([main['AS'], '-v', '/dev/null'],
589                                 exception=False).split()
590
591        if not as_version or compareVersions(as_version[-1], "2.23") < 0:
592            print termcap.Yellow + termcap.Bold + \
593                'Warning: This combination of gcc and binutils have' + \
594                ' known incompatibilities.\n' + \
595                '         If you encounter build problems, please update ' + \
596                'binutils to 2.23.' + \
597                termcap.Normal
598
599    # Add the appropriate Link-Time Optimization (LTO) flags
600    # unless LTO is explicitly turned off. Note that these flags
601    # are only used by the fast target.
602    if not GetOption('no_lto'):
603        # Pass the LTO flag when compiling to produce GIMPLE
604        # output, we merely create the flags here and only append
605        # them later/
606        main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
607
608        # Use the same amount of jobs for LTO as we are running
609        # scons with, we hardcode the use of the linker plugin
610        # which requires either gold or GNU ld >= 2.21
611        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs'),
612                               '-fuse-linker-plugin']
613
614    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
615                                  '-fno-builtin-realloc', '-fno-builtin-free'])
616
617elif main['CLANG']:
618    # Check for a supported version of clang, >= 3.0 is needed to
619    # support similar features as gcc 4.6. See
620    # http://clang.llvm.org/cxx_status.html for details
621    clang_version_re = re.compile(".* version (\d+\.\d+)")
622    clang_version_match = clang_version_re.search(CXX_version)
623    if (clang_version_match):
624        clang_version = clang_version_match.groups()[0]
625        if compareVersions(clang_version, "3.0") < 0:
626            print 'Error: clang version 3.0 or newer required.'
627            print '       Installed version:', clang_version
628            Exit(1)
629    else:
630        print 'Error: Unable to determine clang version.'
631        Exit(1)
632
633    # clang has a few additional warnings that we disable,
634    # tautological comparisons are allowed due to unsigned integers
635    # being compared to constants that happen to be 0, and extraneous
636    # parantheses are allowed due to Ruby's printing of the AST,
637    # finally self assignments are allowed as the generated CPU code
638    # is relying on this
639    main.Append(CCFLAGS=['-Wno-tautological-compare',
640                         '-Wno-parentheses',
641                         '-Wno-self-assign',
642                         # Some versions of libstdc++ (4.8?) seem to
643                         # use struct hash and class hash
644                         # interchangeably.
645                         '-Wno-mismatched-tags',
646                         ])
647
648    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
649
650    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
651    # opposed to libstdc++, as the later is dated.
652    if sys.platform == "darwin":
653        main.Append(CXXFLAGS=['-stdlib=libc++'])
654        main.Append(LIBS=['c++'])
655
656else:
657    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
658    print "Don't know what compiler options to use for your compiler."
659    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
660    print termcap.Yellow + '       version:' + termcap.Normal,
661    if not CXX_version:
662        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
663               termcap.Normal
664    else:
665        print CXX_version.replace('\n', '<nl>')
666    print "       If you're trying to use a compiler other than GCC"
667    print "       or clang, there appears to be something wrong with your"
668    print "       environment."
669    print "       "
670    print "       If you are trying to use a compiler other than those listed"
671    print "       above you will need to ease fix SConstruct and "
672    print "       src/SConscript to support that compiler."
673    Exit(1)
674
675# Set up common yacc/bison flags (needed for Ruby)
676main['YACCFLAGS'] = '-d'
677main['YACCHXXFILESUFFIX'] = '.hh'
678
679# Do this after we save setting back, or else we'll tack on an
680# extra 'qdo' every time we run scons.
681if main['BATCH']:
682    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
683    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
684    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
685    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
686    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
687
688if sys.platform == 'cygwin':
689    # cygwin has some header file issues...
690    main.Append(CCFLAGS=["-Wno-uninitialized"])
691
692# Check for the protobuf compiler
693protoc_version = readCommand([main['PROTOC'], '--version'],
694                             exception='').split()
695
696# First two words should be "libprotoc x.y.z"
697if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
698    print termcap.Yellow + termcap.Bold + \
699        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
700        '         Please install protobuf-compiler for tracing support.' + \
701        termcap.Normal
702    main['PROTOC'] = False
703else:
704    # Based on the availability of the compress stream wrappers,
705    # require 2.1.0
706    min_protoc_version = '2.1.0'
707    if compareVersions(protoc_version[1], min_protoc_version) < 0:
708        print termcap.Yellow + termcap.Bold + \
709            'Warning: protoc version', min_protoc_version, \
710            'or newer required.\n' + \
711            '         Installed version:', protoc_version[1], \
712            termcap.Normal
713        main['PROTOC'] = False
714    else:
715        # Attempt to determine the appropriate include path and
716        # library path using pkg-config, that means we also need to
717        # check for pkg-config. Note that it is possible to use
718        # protobuf without the involvement of pkg-config. Later on we
719        # check go a library config check and at that point the test
720        # will fail if libprotobuf cannot be found.
721        if readCommand(['pkg-config', '--version'], exception=''):
722            try:
723                # Attempt to establish what linking flags to add for protobuf
724                # using pkg-config
725                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
726            except:
727                print termcap.Yellow + termcap.Bold + \
728                    'Warning: pkg-config could not get protobuf flags.' + \
729                    termcap.Normal
730
731# Check for SWIG
732if not main.has_key('SWIG'):
733    print 'Error: SWIG utility not found.'
734    print '       Please install (see http://www.swig.org) and retry.'
735    Exit(1)
736
737# Check for appropriate SWIG version
738swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
739# First 3 words should be "SWIG Version x.y.z"
740if len(swig_version) < 3 or \
741        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
742    print 'Error determining SWIG version.'
743    Exit(1)
744
745min_swig_version = '2.0.4'
746if compareVersions(swig_version[2], min_swig_version) < 0:
747    print 'Error: SWIG version', min_swig_version, 'or newer required.'
748    print '       Installed version:', swig_version[2]
749    Exit(1)
750
751# Set up SWIG flags & scanner
752swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
753main.Append(SWIGFLAGS=swig_flags)
754
755# Check for 'timeout' from GNU coreutils.  If present, regressions
756# will be run with a time limit.
757TIMEOUT_version = readCommand(['timeout', '--version'], exception=False)
758main['TIMEOUT'] = TIMEOUT_version and TIMEOUT_version.find('timeout') == 0
759
760# filter out all existing swig scanners, they mess up the dependency
761# stuff for some reason
762scanners = []
763for scanner in main['SCANNERS']:
764    skeys = scanner.skeys
765    if skeys == '.i':
766        continue
767
768    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
769        continue
770
771    scanners.append(scanner)
772
773# add the new swig scanner that we like better
774from SCons.Scanner import ClassicCPP as CPPScanner
775swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
776scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
777
778# replace the scanners list that has what we want
779main['SCANNERS'] = scanners
780
781# Add a custom Check function to the Configure context so that we can
782# figure out if the compiler adds leading underscores to global
783# variables.  This is needed for the autogenerated asm files that we
784# use for embedding the python code.
785def CheckLeading(context):
786    context.Message("Checking for leading underscore in global variables...")
787    # 1) Define a global variable called x from asm so the C compiler
788    #    won't change the symbol at all.
789    # 2) Declare that variable.
790    # 3) Use the variable
791    #
792    # If the compiler prepends an underscore, this will successfully
793    # link because the external symbol 'x' will be called '_x' which
794    # was defined by the asm statement.  If the compiler does not
795    # prepend an underscore, this will not successfully link because
796    # '_x' will have been defined by assembly, while the C portion of
797    # the code will be trying to use 'x'
798    ret = context.TryLink('''
799        asm(".globl _x; _x: .byte 0");
800        extern int x;
801        int main() { return x; }
802        ''', extension=".c")
803    context.env.Append(LEADING_UNDERSCORE=ret)
804    context.Result(ret)
805    return ret
806
807# Add a custom Check function to test for structure members.
808def CheckMember(context, include, decl, member, include_quotes="<>"):
809    context.Message("Checking for member %s in %s..." %
810                    (member, decl))
811    text = """
812#include %(header)s
813int main(){
814  %(decl)s test;
815  (void)test.%(member)s;
816  return 0;
817};
818""" % { "header" : include_quotes[0] + include + include_quotes[1],
819        "decl" : decl,
820        "member" : member,
821        }
822
823    ret = context.TryCompile(text, extension=".cc")
824    context.Result(ret)
825    return ret
826
827# Platform-specific configuration.  Note again that we assume that all
828# builds under a given build root run on the same host platform.
829conf = Configure(main,
830                 conf_dir = joinpath(build_root, '.scons_config'),
831                 log_file = joinpath(build_root, 'scons_config.log'),
832                 custom_tests = {
833        'CheckLeading' : CheckLeading,
834        'CheckMember' : CheckMember,
835        })
836
837# Check for leading underscores.  Don't really need to worry either
838# way so don't need to check the return code.
839conf.CheckLeading()
840
841# Check if we should compile a 64 bit binary on Mac OS X/Darwin
842try:
843    import platform
844    uname = platform.uname()
845    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
846        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
847            main.Append(CCFLAGS=['-arch', 'x86_64'])
848            main.Append(CFLAGS=['-arch', 'x86_64'])
849            main.Append(LINKFLAGS=['-arch', 'x86_64'])
850            main.Append(ASFLAGS=['-arch', 'x86_64'])
851except:
852    pass
853
854# Recent versions of scons substitute a "Null" object for Configure()
855# when configuration isn't necessary, e.g., if the "--help" option is
856# present.  Unfortuantely this Null object always returns false,
857# breaking all our configuration checks.  We replace it with our own
858# more optimistic null object that returns True instead.
859if not conf:
860    def NullCheck(*args, **kwargs):
861        return True
862
863    class NullConf:
864        def __init__(self, env):
865            self.env = env
866        def Finish(self):
867            return self.env
868        def __getattr__(self, mname):
869            return NullCheck
870
871    conf = NullConf(main)
872
873# Cache build files in the supplied directory.
874if main['M5_BUILD_CACHE']:
875    print 'Using build cache located at', main['M5_BUILD_CACHE']
876    CacheDir(main['M5_BUILD_CACHE'])
877
878# Find Python include and library directories for embedding the
879# interpreter. We rely on python-config to resolve the appropriate
880# includes and linker flags. ParseConfig does not seem to understand
881# the more exotic linker flags such as -Xlinker and -export-dynamic so
882# we add them explicitly below. If you want to link in an alternate
883# version of python, see above for instructions on how to invoke
884# scons with the appropriate PATH set.
885#
886# First we check if python2-config exists, else we use python-config
887python_config = readCommand(['which', 'python2-config'], exception='').strip()
888if not os.path.exists(python_config):
889    python_config = readCommand(['which', 'python-config'],
890                                exception='').strip()
891py_includes = readCommand([python_config, '--includes'],
892                          exception='').split()
893# Strip the -I from the include folders before adding them to the
894# CPPPATH
895main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
896
897# Read the linker flags and split them into libraries and other link
898# flags. The libraries are added later through the call the CheckLib.
899py_ld_flags = readCommand([python_config, '--ldflags'], exception='').split()
900py_libs = []
901for lib in py_ld_flags:
902     if not lib.startswith('-l'):
903         main.Append(LINKFLAGS=[lib])
904     else:
905         lib = lib[2:]
906         if lib not in py_libs:
907             py_libs.append(lib)
908
909# verify that this stuff works
910if not conf.CheckHeader('Python.h', '<>'):
911    print "Error: can't find Python.h header in", py_includes
912    print "Install Python headers (package python-dev on Ubuntu and RedHat)"
913    Exit(1)
914
915for lib in py_libs:
916    if not conf.CheckLib(lib):
917        print "Error: can't find library %s required by python" % lib
918        Exit(1)
919
920# On Solaris you need to use libsocket for socket ops
921if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
922   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
923       print "Can't find library with socket calls (e.g. accept())"
924       Exit(1)
925
926# Check for zlib.  If the check passes, libz will be automatically
927# added to the LIBS environment variable.
928if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
929    print 'Error: did not find needed zlib compression library '\
930          'and/or zlib.h header file.'
931    print '       Please install zlib and try again.'
932    Exit(1)
933
934# If we have the protobuf compiler, also make sure we have the
935# development libraries. If the check passes, libprotobuf will be
936# automatically added to the LIBS environment variable. After
937# this, we can use the HAVE_PROTOBUF flag to determine if we have
938# got both protoc and libprotobuf available.
939main['HAVE_PROTOBUF'] = main['PROTOC'] and \
940    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
941                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
942
943# If we have the compiler but not the library, print another warning.
944if main['PROTOC'] and not main['HAVE_PROTOBUF']:
945    print termcap.Yellow + termcap.Bold + \
946        'Warning: did not find protocol buffer library and/or headers.\n' + \
947    '       Please install libprotobuf-dev for tracing support.' + \
948    termcap.Normal
949
950# Check for librt.
951have_posix_clock = \
952    conf.CheckLibWithHeader(None, 'time.h', 'C',
953                            'clock_nanosleep(0,0,NULL,NULL);') or \
954    conf.CheckLibWithHeader('rt', 'time.h', 'C',
955                            'clock_nanosleep(0,0,NULL,NULL);')
956
957have_posix_timers = \
958    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
959                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
960
961if conf.CheckLib('tcmalloc'):
962    main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
963elif conf.CheckLib('tcmalloc_minimal'):
964    main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
965else:
966    print termcap.Yellow + termcap.Bold + \
967          "You can get a 12% performance improvement by installing tcmalloc "\
968          "(libgoogle-perftools-dev package on Ubuntu or RedHat)." + \
969          termcap.Normal
970
971if not have_posix_clock:
972    print "Can't find library for POSIX clocks."
973
974# Check for <fenv.h> (C99 FP environment control)
975have_fenv = conf.CheckHeader('fenv.h', '<>')
976if not have_fenv:
977    print "Warning: Header file <fenv.h> not found."
978    print "         This host has no IEEE FP rounding mode control."
979
980# Check if we should enable KVM-based hardware virtualization. The API
981# we rely on exists since version 2.6.36 of the kernel, but somehow
982# the KVM_API_VERSION does not reflect the change. We test for one of
983# the types as a fall back.
984have_kvm = conf.CheckHeader('linux/kvm.h', '<>') and \
985    conf.CheckTypeSize('struct kvm_xsave', '#include <linux/kvm.h>') != 0
986if not have_kvm:
987    print "Info: Compatible header file <linux/kvm.h> not found, " \
988        "disabling KVM support."
989
990# Check if the requested target ISA is compatible with the host
991def is_isa_kvm_compatible(isa):
992    isa_comp_table = {
993        "arm" : ( "armv7l" ),
994        "x86" : ( "x86_64" ),
995        }
996    try:
997        import platform
998        host_isa = platform.machine()
999    except:
1000        print "Warning: Failed to determine host ISA."
1001        return False
1002
1003    return host_isa in isa_comp_table.get(isa, [])
1004
1005
1006# Check if the exclude_host attribute is available. We want this to
1007# get accurate instruction counts in KVM.
1008main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1009    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1010
1011
1012######################################################################
1013#
1014# Finish the configuration
1015#
1016main = conf.Finish()
1017
1018######################################################################
1019#
1020# Collect all non-global variables
1021#
1022
1023# Define the universe of supported ISAs
1024all_isa_list = [ ]
1025Export('all_isa_list')
1026
1027class CpuModel(object):
1028    '''The CpuModel class encapsulates everything the ISA parser needs to
1029    know about a particular CPU model.'''
1030
1031    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1032    dict = {}
1033
1034    # Constructor.  Automatically adds models to CpuModel.dict.
1035    def __init__(self, name, default=False):
1036        self.name = name           # name of model
1037
1038        # This cpu is enabled by default
1039        self.default = default
1040
1041        # Add self to dict
1042        if name in CpuModel.dict:
1043            raise AttributeError, "CpuModel '%s' already registered" % name
1044        CpuModel.dict[name] = self
1045
1046Export('CpuModel')
1047
1048# Sticky variables get saved in the variables file so they persist from
1049# one invocation to the next (unless overridden, in which case the new
1050# value becomes sticky).
1051sticky_vars = Variables(args=ARGUMENTS)
1052Export('sticky_vars')
1053
1054# Sticky variables that should be exported
1055export_vars = []
1056Export('export_vars')
1057
1058# For Ruby
1059all_protocols = []
1060Export('all_protocols')
1061protocol_dirs = []
1062Export('protocol_dirs')
1063slicc_includes = []
1064Export('slicc_includes')
1065
1066# Walk the tree and execute all SConsopts scripts that wil add to the
1067# above variables
1068if GetOption('verbose'):
1069    print "Reading SConsopts"
1070for bdir in [ base_dir ] + extras_dir_list:
1071    if not isdir(bdir):
1072        print "Error: directory '%s' does not exist" % bdir
1073        Exit(1)
1074    for root, dirs, files in os.walk(bdir):
1075        if 'SConsopts' in files:
1076            if GetOption('verbose'):
1077                print "Reading", joinpath(root, 'SConsopts')
1078            SConscript(joinpath(root, 'SConsopts'))
1079
1080all_isa_list.sort()
1081
1082sticky_vars.AddVariables(
1083    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1084    ListVariable('CPU_MODELS', 'CPU models',
1085                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1086                 sorted(CpuModel.dict.keys())),
1087    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1088                 False),
1089    BoolVariable('SS_COMPATIBLE_FP',
1090                 'Make floating-point results compatible with SimpleScalar',
1091                 False),
1092    BoolVariable('USE_SSE2',
1093                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1094                 False),
1095    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1096    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1097    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1098    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1099    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1100                  all_protocols),
1101    )
1102
1103# These variables get exported to #defines in config/*.hh (see src/SConscript).
1104export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
1105                'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF',
1106                'HAVE_PERF_ATTR_EXCLUDE_HOST']
1107
1108###################################################
1109#
1110# Define a SCons builder for configuration flag headers.
1111#
1112###################################################
1113
1114# This function generates a config header file that #defines the
1115# variable symbol to the current variable setting (0 or 1).  The source
1116# operands are the name of the variable and a Value node containing the
1117# value of the variable.
1118def build_config_file(target, source, env):
1119    (variable, value) = [s.get_contents() for s in source]
1120    f = file(str(target[0]), 'w')
1121    print >> f, '#define', variable, value
1122    f.close()
1123    return None
1124
1125# Combine the two functions into a scons Action object.
1126config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1127
1128# The emitter munges the source & target node lists to reflect what
1129# we're really doing.
1130def config_emitter(target, source, env):
1131    # extract variable name from Builder arg
1132    variable = str(target[0])
1133    # True target is config header file
1134    target = joinpath('config', variable.lower() + '.hh')
1135    val = env[variable]
1136    if isinstance(val, bool):
1137        # Force value to 0/1
1138        val = int(val)
1139    elif isinstance(val, str):
1140        val = '"' + val + '"'
1141
1142    # Sources are variable name & value (packaged in SCons Value nodes)
1143    return ([target], [Value(variable), Value(val)])
1144
1145config_builder = Builder(emitter = config_emitter, action = config_action)
1146
1147main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1148
1149# libelf build is shared across all configs in the build root.
1150main.SConscript('ext/libelf/SConscript',
1151                variant_dir = joinpath(build_root, 'libelf'))
1152
1153# gzstream build is shared across all configs in the build root.
1154main.SConscript('ext/gzstream/SConscript',
1155                variant_dir = joinpath(build_root, 'gzstream'))
1156
1157# libfdt build is shared across all configs in the build root.
1158main.SConscript('ext/libfdt/SConscript',
1159                variant_dir = joinpath(build_root, 'libfdt'))
1160
1161# fputils build is shared across all configs in the build root.
1162main.SConscript('ext/fputils/SConscript',
1163                variant_dir = joinpath(build_root, 'fputils'))
1164
1165# DRAMSim2 build is shared across all configs in the build root.
1166main.SConscript('ext/dramsim2/SConscript',
1167                variant_dir = joinpath(build_root, 'dramsim2'))
1168
1169###################################################
1170#
1171# This function is used to set up a directory with switching headers
1172#
1173###################################################
1174
1175main['ALL_ISA_LIST'] = all_isa_list
1176all_isa_deps = {}
1177def make_switching_dir(dname, switch_headers, env):
1178    # Generate the header.  target[0] is the full path of the output
1179    # header to generate.  'source' is a dummy variable, since we get the
1180    # list of ISAs from env['ALL_ISA_LIST'].
1181    def gen_switch_hdr(target, source, env):
1182        fname = str(target[0])
1183        isa = env['TARGET_ISA'].lower()
1184        try:
1185            f = open(fname, 'w')
1186            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1187            f.close()
1188        except IOError:
1189            print "Failed to create %s" % fname
1190            raise
1191
1192    # Build SCons Action object. 'varlist' specifies env vars that this
1193    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1194    # should get re-executed.
1195    switch_hdr_action = MakeAction(gen_switch_hdr,
1196                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1197
1198    # Instantiate actions for each header
1199    for hdr in switch_headers:
1200        env.Command(hdr, [], switch_hdr_action)
1201
1202    isa_target = Dir('.').up().name.lower().replace('_', '-')
1203    env['PHONY_BASE'] = '#'+isa_target
1204    all_isa_deps[isa_target] = None
1205
1206Export('make_switching_dir')
1207
1208# all-isas -> all-deps -> all-environs -> all_targets
1209main.Alias('#all-isas', [])
1210main.Alias('#all-deps', '#all-isas')
1211
1212# Dummy target to ensure all environments are created before telling
1213# SCons what to actually make (the command line arguments).  We attach
1214# them to the dependence graph after the environments are complete.
1215ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1216def environsComplete(target, source, env):
1217    for t in ORIG_BUILD_TARGETS:
1218        main.Depends('#all-targets', t)
1219
1220# Each build/* switching_dir attaches its *-environs target to #all-environs.
1221main.Append(BUILDERS = {'CompleteEnvirons' :
1222                        Builder(action=MakeAction(environsComplete, None))})
1223main.CompleteEnvirons('#all-environs', [])
1224
1225def doNothing(**ignored): pass
1226main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1227
1228# The final target to which all the original targets ultimately get attached.
1229main.Dummy('#all-targets', '#all-environs')
1230BUILD_TARGETS[:] = ['#all-targets']
1231
1232###################################################
1233#
1234# Define build environments for selected configurations.
1235#
1236###################################################
1237
1238for variant_path in variant_paths:
1239    if not GetOption('silent'):
1240        print "Building in", variant_path
1241
1242    # Make a copy of the build-root environment to use for this config.
1243    env = main.Clone()
1244    env['BUILDDIR'] = variant_path
1245
1246    # variant_dir is the tail component of build path, and is used to
1247    # determine the build parameters (e.g., 'ALPHA_SE')
1248    (build_root, variant_dir) = splitpath(variant_path)
1249
1250    # Set env variables according to the build directory config.
1251    sticky_vars.files = []
1252    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1253    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1254    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1255    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1256    if isfile(current_vars_file):
1257        sticky_vars.files.append(current_vars_file)
1258        if not GetOption('silent'):
1259            print "Using saved variables file %s" % current_vars_file
1260    else:
1261        # Build dir-specific variables file doesn't exist.
1262
1263        # Make sure the directory is there so we can create it later
1264        opt_dir = dirname(current_vars_file)
1265        if not isdir(opt_dir):
1266            mkdir(opt_dir)
1267
1268        # Get default build variables from source tree.  Variables are
1269        # normally determined by name of $VARIANT_DIR, but can be
1270        # overridden by '--default=' arg on command line.
1271        default = GetOption('default')
1272        opts_dir = joinpath(main.root.abspath, 'build_opts')
1273        if default:
1274            default_vars_files = [joinpath(build_root, 'variables', default),
1275                                  joinpath(opts_dir, default)]
1276        else:
1277            default_vars_files = [joinpath(opts_dir, variant_dir)]
1278        existing_files = filter(isfile, default_vars_files)
1279        if existing_files:
1280            default_vars_file = existing_files[0]
1281            sticky_vars.files.append(default_vars_file)
1282            print "Variables file %s not found,\n  using defaults in %s" \
1283                  % (current_vars_file, default_vars_file)
1284        else:
1285            print "Error: cannot find variables file %s or " \
1286                  "default file(s) %s" \
1287                  % (current_vars_file, ' or '.join(default_vars_files))
1288            Exit(1)
1289
1290    # Apply current variable settings to env
1291    sticky_vars.Update(env)
1292
1293    help_texts["local_vars"] += \
1294        "Build variables for %s:\n" % variant_dir \
1295                 + sticky_vars.GenerateHelpText(env)
1296
1297    # Process variable settings.
1298
1299    if not have_fenv and env['USE_FENV']:
1300        print "Warning: <fenv.h> not available; " \
1301              "forcing USE_FENV to False in", variant_dir + "."
1302        env['USE_FENV'] = False
1303
1304    if not env['USE_FENV']:
1305        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1306        print "         FP results may deviate slightly from other platforms."
1307
1308    if env['EFENCE']:
1309        env.Append(LIBS=['efence'])
1310
1311    if env['USE_KVM']:
1312        if not have_kvm:
1313            print "Warning: Can not enable KVM, host seems to lack KVM support"
1314            env['USE_KVM'] = False
1315        elif not have_posix_timers:
1316            print "Warning: Can not enable KVM, host seems to lack support " \
1317                "for POSIX timers"
1318            env['USE_KVM'] = False
1319        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1320            print "Info: KVM support disabled due to unsupported host and " \
1321                "target ISA combination"
1322            env['USE_KVM'] = False
1323
1324    # Warn about missing optional functionality
1325    if env['USE_KVM']:
1326        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1327            print "Warning: perf_event headers lack support for the " \
1328                "exclude_host attribute. KVM instruction counts will " \
1329                "be inaccurate."
1330
1331    # Save sticky variable settings back to current variables file
1332    sticky_vars.Save(current_vars_file, env)
1333
1334    if env['USE_SSE2']:
1335        env.Append(CCFLAGS=['-msse2'])
1336
1337    # The src/SConscript file sets up the build rules in 'env' according
1338    # to the configured variables.  It returns a list of environments,
1339    # one for each variant build (debug, opt, etc.)
1340    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1341
1342def pairwise(iterable):
1343    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1344    a, b = itertools.tee(iterable)
1345    b.next()
1346    return itertools.izip(a, b)
1347
1348# Create false dependencies so SCons will parse ISAs, establish
1349# dependencies, and setup the build Environments serially. Either
1350# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1351# greater than 1. It appears to be standard race condition stuff; it
1352# doesn't always fail, but usually, and the behaviors are different.
1353# Every time I tried to remove this, builds would fail in some
1354# creative new way. So, don't do that. You'll want to, though, because
1355# tests/SConscript takes a long time to make its Environments.
1356for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1357    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1358    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1359
1360# base help text
1361Help('''
1362Usage: scons [scons options] [build variables] [target(s)]
1363
1364Extra scons options:
1365%(options)s
1366
1367Global build variables:
1368%(global_vars)s
1369
1370%(local_vars)s
1371''' % help_texts)
1372