SConstruct revision 10425
16691Stjones1@inf.ed.ac.uk# -*- mode:python -*-
26691Stjones1@inf.ed.ac.uk
36691Stjones1@inf.ed.ac.uk# Copyright (c) 2013 ARM Limited
46691Stjones1@inf.ed.ac.uk# All rights reserved.
56691Stjones1@inf.ed.ac.uk#
66691Stjones1@inf.ed.ac.uk# The license below extends only to copyright in the software and shall
76691Stjones1@inf.ed.ac.uk# not be construed as granting a license to any other intellectual
86691Stjones1@inf.ed.ac.uk# property including but not limited to intellectual property relating
96691Stjones1@inf.ed.ac.uk# to a hardware implementation of the functionality of the software
106691Stjones1@inf.ed.ac.uk# licensed hereunder.  You may use the software subject to the license
116691Stjones1@inf.ed.ac.uk# terms below provided that you ensure that this notice is replicated
126691Stjones1@inf.ed.ac.uk# unmodified and in its entirety in all distributions of the software,
136691Stjones1@inf.ed.ac.uk# modified or unmodified, in source code or in binary form.
146691Stjones1@inf.ed.ac.uk#
156691Stjones1@inf.ed.ac.uk# Copyright (c) 2011 Advanced Micro Devices, Inc.
166691Stjones1@inf.ed.ac.uk# Copyright (c) 2009 The Hewlett-Packard Development Company
176691Stjones1@inf.ed.ac.uk# Copyright (c) 2004-2005 The Regents of The University of Michigan
186691Stjones1@inf.ed.ac.uk# All rights reserved.
196691Stjones1@inf.ed.ac.uk#
206691Stjones1@inf.ed.ac.uk# Redistribution and use in source and binary forms, with or without
216691Stjones1@inf.ed.ac.uk# modification, are permitted provided that the following conditions are
226691Stjones1@inf.ed.ac.uk# met: redistributions of source code must retain the above copyright
236691Stjones1@inf.ed.ac.uk# notice, this list of conditions and the following disclaimer;
246691Stjones1@inf.ed.ac.uk# redistributions in binary form must reproduce the above copyright
256691Stjones1@inf.ed.ac.uk# notice, this list of conditions and the following disclaimer in the
266691Stjones1@inf.ed.ac.uk# documentation and/or other materials provided with the distribution;
276691Stjones1@inf.ed.ac.uk# neither the name of the copyright holders nor the names of its
286691Stjones1@inf.ed.ac.uk# contributors may be used to endorse or promote products derived from
296691Stjones1@inf.ed.ac.uk# this software without specific prior written permission.
306691Stjones1@inf.ed.ac.uk#
316691Stjones1@inf.ed.ac.uk# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
326691Stjones1@inf.ed.ac.uk# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
336691Stjones1@inf.ed.ac.uk# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
346691Stjones1@inf.ed.ac.uk# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
356691Stjones1@inf.ed.ac.uk# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
366691Stjones1@inf.ed.ac.uk# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
379022Sgblack@eecs.umich.edu# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
386691Stjones1@inf.ed.ac.uk# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
396691Stjones1@inf.ed.ac.uk# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
406691Stjones1@inf.ed.ac.uk# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
416691Stjones1@inf.ed.ac.uk# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
426691Stjones1@inf.ed.ac.uk#
436691Stjones1@inf.ed.ac.uk# Authors: Steve Reinhardt
448745Sgblack@eecs.umich.edu#          Nathan Binkert
458772Sgblack@eecs.umich.edu
468772Sgblack@eecs.umich.edu###################################################
476691Stjones1@inf.ed.ac.uk#
488772Sgblack@eecs.umich.edu# SCons top-level build description (SConstruct) file.
498792Sgblack@eecs.umich.edu#
506691Stjones1@inf.ed.ac.uk# While in this directory ('gem5'), just type 'scons' to build the default
517506Stjones1@inf.ed.ac.uk# configuration (see below), or type 'scons build/<CONFIG>/<binary>'
528759Sgblack@eecs.umich.edu# to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
536691Stjones1@inf.ed.ac.uk# the optimized full-system version).
548745Sgblack@eecs.umich.edu#
556691Stjones1@inf.ed.ac.uk# You can build gem5 in a different directory as long as there is a
568745Sgblack@eecs.umich.edu# 'build/<CONFIG>' somewhere along the target path.  The build system
578335Snate@binkert.org# expects that all configs under the same build directory are being
586691Stjones1@inf.ed.ac.uk# built for the same host system.
596691Stjones1@inf.ed.ac.uk#
606691Stjones1@inf.ed.ac.uk# Examples:
616691Stjones1@inf.ed.ac.uk#
626691Stjones1@inf.ed.ac.uk#   The following two commands are equivalent.  The '-u' option tells
636691Stjones1@inf.ed.ac.uk#   scons to search up the directory tree for this SConstruct file.
646691Stjones1@inf.ed.ac.uk#   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
656691Stjones1@inf.ed.ac.uk#   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
666691Stjones1@inf.ed.ac.uk#
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
610        main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
611
612    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin-malloc', '-fno-builtin-calloc',
613                                  '-fno-builtin-realloc', '-fno-builtin-free'])
614
615elif main['CLANG']:
616    # Check for a supported version of clang, >= 3.0 is needed to
617    # support similar features as gcc 4.6. See
618    # http://clang.llvm.org/cxx_status.html for details
619    clang_version_re = re.compile(".* version (\d+\.\d+)")
620    clang_version_match = clang_version_re.search(CXX_version)
621    if (clang_version_match):
622        clang_version = clang_version_match.groups()[0]
623        if compareVersions(clang_version, "3.0") < 0:
624            print 'Error: clang version 3.0 or newer required.'
625            print '       Installed version:', clang_version
626            Exit(1)
627    else:
628        print 'Error: Unable to determine clang version.'
629        Exit(1)
630
631    # clang has a few additional warnings that we disable,
632    # tautological comparisons are allowed due to unsigned integers
633    # being compared to constants that happen to be 0, and extraneous
634    # parantheses are allowed due to Ruby's printing of the AST,
635    # finally self assignments are allowed as the generated CPU code
636    # is relying on this
637    main.Append(CCFLAGS=['-Wno-tautological-compare',
638                         '-Wno-parentheses',
639                         '-Wno-self-assign',
640                         # Some versions of libstdc++ (4.8?) seem to
641                         # use struct hash and class hash
642                         # interchangeably.
643                         '-Wno-mismatched-tags',
644                         ])
645
646    main.Append(TCMALLOC_CCFLAGS=['-fno-builtin'])
647
648    # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
649    # opposed to libstdc++, as the later is dated.
650    if sys.platform == "darwin":
651        main.Append(CXXFLAGS=['-stdlib=libc++'])
652        main.Append(LIBS=['c++'])
653
654else:
655    print termcap.Yellow + termcap.Bold + 'Error' + termcap.Normal,
656    print "Don't know what compiler options to use for your compiler."
657    print termcap.Yellow + '       compiler:' + termcap.Normal, main['CXX']
658    print termcap.Yellow + '       version:' + termcap.Normal,
659    if not CXX_version:
660        print termcap.Yellow + termcap.Bold + "COMMAND NOT FOUND!" +\
661               termcap.Normal
662    else:
663        print CXX_version.replace('\n', '<nl>')
664    print "       If you're trying to use a compiler other than GCC"
665    print "       or clang, there appears to be something wrong with your"
666    print "       environment."
667    print "       "
668    print "       If you are trying to use a compiler other than those listed"
669    print "       above you will need to ease fix SConstruct and "
670    print "       src/SConscript to support that compiler."
671    Exit(1)
672
673# Set up common yacc/bison flags (needed for Ruby)
674main['YACCFLAGS'] = '-d'
675main['YACCHXXFILESUFFIX'] = '.hh'
676
677# Do this after we save setting back, or else we'll tack on an
678# extra 'qdo' every time we run scons.
679if main['BATCH']:
680    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
681    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
682    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
683    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
684    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
685
686if sys.platform == 'cygwin':
687    # cygwin has some header file issues...
688    main.Append(CCFLAGS=["-Wno-uninitialized"])
689
690# Check for the protobuf compiler
691protoc_version = readCommand([main['PROTOC'], '--version'],
692                             exception='').split()
693
694# First two words should be "libprotoc x.y.z"
695if len(protoc_version) < 2 or protoc_version[0] != 'libprotoc':
696    print termcap.Yellow + termcap.Bold + \
697        'Warning: Protocol buffer compiler (protoc) not found.\n' + \
698        '         Please install protobuf-compiler for tracing support.' + \
699        termcap.Normal
700    main['PROTOC'] = False
701else:
702    # Based on the availability of the compress stream wrappers,
703    # require 2.1.0
704    min_protoc_version = '2.1.0'
705    if compareVersions(protoc_version[1], min_protoc_version) < 0:
706        print termcap.Yellow + termcap.Bold + \
707            'Warning: protoc version', min_protoc_version, \
708            'or newer required.\n' + \
709            '         Installed version:', protoc_version[1], \
710            termcap.Normal
711        main['PROTOC'] = False
712    else:
713        # Attempt to determine the appropriate include path and
714        # library path using pkg-config, that means we also need to
715        # check for pkg-config. Note that it is possible to use
716        # protobuf without the involvement of pkg-config. Later on we
717        # check go a library config check and at that point the test
718        # will fail if libprotobuf cannot be found.
719        if readCommand(['pkg-config', '--version'], exception=''):
720            try:
721                # Attempt to establish what linking flags to add for protobuf
722                # using pkg-config
723                main.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
724            except:
725                print termcap.Yellow + termcap.Bold + \
726                    'Warning: pkg-config could not get protobuf flags.' + \
727                    termcap.Normal
728
729# Check for SWIG
730if not main.has_key('SWIG'):
731    print 'Error: SWIG utility not found.'
732    print '       Please install (see http://www.swig.org) and retry.'
733    Exit(1)
734
735# Check for appropriate SWIG version
736swig_version = readCommand([main['SWIG'], '-version'], exception='').split()
737# First 3 words should be "SWIG Version x.y.z"
738if len(swig_version) < 3 or \
739        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
740    print 'Error determining SWIG version.'
741    Exit(1)
742
743min_swig_version = '2.0.4'
744if compareVersions(swig_version[2], min_swig_version) < 0:
745    print 'Error: SWIG version', min_swig_version, 'or newer required.'
746    print '       Installed version:', swig_version[2]
747    Exit(1)
748
749# Check for known incompatibilities. The standard library shipped with
750# gcc >= 4.9 does not play well with swig versions prior to 3.0
751if main['GCC'] and compareVersions(gcc_version, '4.9') >= 0 and \
752        compareVersions(swig_version[2], '3.0') < 0:
753    print termcap.Yellow + termcap.Bold + \
754        'Warning: This combination of gcc and swig have' + \
755        ' known incompatibilities.\n' + \
756        '         If you encounter build problems, please update ' + \
757        'swig to 3.0 or later.' + \
758        termcap.Normal
759
760# Set up SWIG flags & scanner
761swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
762main.Append(SWIGFLAGS=swig_flags)
763
764# Check for 'timeout' from GNU coreutils.  If present, regressions
765# will be run with a time limit.
766TIMEOUT_version = readCommand(['timeout', '--version'], exception=False)
767main['TIMEOUT'] = TIMEOUT_version and TIMEOUT_version.find('timeout') == 0
768
769# filter out all existing swig scanners, they mess up the dependency
770# stuff for some reason
771scanners = []
772for scanner in main['SCANNERS']:
773    skeys = scanner.skeys
774    if skeys == '.i':
775        continue
776
777    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
778        continue
779
780    scanners.append(scanner)
781
782# add the new swig scanner that we like better
783from SCons.Scanner import ClassicCPP as CPPScanner
784swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
785scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
786
787# replace the scanners list that has what we want
788main['SCANNERS'] = scanners
789
790# Add a custom Check function to the Configure context so that we can
791# figure out if the compiler adds leading underscores to global
792# variables.  This is needed for the autogenerated asm files that we
793# use for embedding the python code.
794def CheckLeading(context):
795    context.Message("Checking for leading underscore in global variables...")
796    # 1) Define a global variable called x from asm so the C compiler
797    #    won't change the symbol at all.
798    # 2) Declare that variable.
799    # 3) Use the variable
800    #
801    # If the compiler prepends an underscore, this will successfully
802    # link because the external symbol 'x' will be called '_x' which
803    # was defined by the asm statement.  If the compiler does not
804    # prepend an underscore, this will not successfully link because
805    # '_x' will have been defined by assembly, while the C portion of
806    # the code will be trying to use 'x'
807    ret = context.TryLink('''
808        asm(".globl _x; _x: .byte 0");
809        extern int x;
810        int main() { return x; }
811        ''', extension=".c")
812    context.env.Append(LEADING_UNDERSCORE=ret)
813    context.Result(ret)
814    return ret
815
816# Add a custom Check function to test for structure members.
817def CheckMember(context, include, decl, member, include_quotes="<>"):
818    context.Message("Checking for member %s in %s..." %
819                    (member, decl))
820    text = """
821#include %(header)s
822int main(){
823  %(decl)s test;
824  (void)test.%(member)s;
825  return 0;
826};
827""" % { "header" : include_quotes[0] + include + include_quotes[1],
828        "decl" : decl,
829        "member" : member,
830        }
831
832    ret = context.TryCompile(text, extension=".cc")
833    context.Result(ret)
834    return ret
835
836# Platform-specific configuration.  Note again that we assume that all
837# builds under a given build root run on the same host platform.
838conf = Configure(main,
839                 conf_dir = joinpath(build_root, '.scons_config'),
840                 log_file = joinpath(build_root, 'scons_config.log'),
841                 custom_tests = {
842        'CheckLeading' : CheckLeading,
843        'CheckMember' : CheckMember,
844        })
845
846# Check for leading underscores.  Don't really need to worry either
847# way so don't need to check the return code.
848conf.CheckLeading()
849
850# Check if we should compile a 64 bit binary on Mac OS X/Darwin
851try:
852    import platform
853    uname = platform.uname()
854    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
855        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
856            main.Append(CCFLAGS=['-arch', 'x86_64'])
857            main.Append(CFLAGS=['-arch', 'x86_64'])
858            main.Append(LINKFLAGS=['-arch', 'x86_64'])
859            main.Append(ASFLAGS=['-arch', 'x86_64'])
860except:
861    pass
862
863# Recent versions of scons substitute a "Null" object for Configure()
864# when configuration isn't necessary, e.g., if the "--help" option is
865# present.  Unfortuantely this Null object always returns false,
866# breaking all our configuration checks.  We replace it with our own
867# more optimistic null object that returns True instead.
868if not conf:
869    def NullCheck(*args, **kwargs):
870        return True
871
872    class NullConf:
873        def __init__(self, env):
874            self.env = env
875        def Finish(self):
876            return self.env
877        def __getattr__(self, mname):
878            return NullCheck
879
880    conf = NullConf(main)
881
882# Cache build files in the supplied directory.
883if main['M5_BUILD_CACHE']:
884    print 'Using build cache located at', main['M5_BUILD_CACHE']
885    CacheDir(main['M5_BUILD_CACHE'])
886
887# Find Python include and library directories for embedding the
888# interpreter. We rely on python-config to resolve the appropriate
889# includes and linker flags. ParseConfig does not seem to understand
890# the more exotic linker flags such as -Xlinker and -export-dynamic so
891# we add them explicitly below. If you want to link in an alternate
892# version of python, see above for instructions on how to invoke
893# scons with the appropriate PATH set.
894#
895# First we check if python2-config exists, else we use python-config
896python_config = readCommand(['which', 'python2-config'], exception='').strip()
897if not os.path.exists(python_config):
898    python_config = readCommand(['which', 'python-config'],
899                                exception='').strip()
900py_includes = readCommand([python_config, '--includes'],
901                          exception='').split()
902# Strip the -I from the include folders before adding them to the
903# CPPPATH
904main.Append(CPPPATH=map(lambda inc: inc[2:], py_includes))
905
906# Read the linker flags and split them into libraries and other link
907# flags. The libraries are added later through the call the CheckLib.
908py_ld_flags = readCommand([python_config, '--ldflags'], exception='').split()
909py_libs = []
910for lib in py_ld_flags:
911     if not lib.startswith('-l'):
912         main.Append(LINKFLAGS=[lib])
913     else:
914         lib = lib[2:]
915         if lib not in py_libs:
916             py_libs.append(lib)
917
918# verify that this stuff works
919if not conf.CheckHeader('Python.h', '<>'):
920    print "Error: can't find Python.h header in", py_includes
921    print "Install Python headers (package python-dev on Ubuntu and RedHat)"
922    Exit(1)
923
924for lib in py_libs:
925    if not conf.CheckLib(lib):
926        print "Error: can't find library %s required by python" % lib
927        Exit(1)
928
929# On Solaris you need to use libsocket for socket ops
930if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
931   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
932       print "Can't find library with socket calls (e.g. accept())"
933       Exit(1)
934
935# Check for zlib.  If the check passes, libz will be automatically
936# added to the LIBS environment variable.
937if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
938    print 'Error: did not find needed zlib compression library '\
939          'and/or zlib.h header file.'
940    print '       Please install zlib and try again.'
941    Exit(1)
942
943# If we have the protobuf compiler, also make sure we have the
944# development libraries. If the check passes, libprotobuf will be
945# automatically added to the LIBS environment variable. After
946# this, we can use the HAVE_PROTOBUF flag to determine if we have
947# got both protoc and libprotobuf available.
948main['HAVE_PROTOBUF'] = main['PROTOC'] and \
949    conf.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
950                            'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
951
952# If we have the compiler but not the library, print another warning.
953if main['PROTOC'] and not main['HAVE_PROTOBUF']:
954    print termcap.Yellow + termcap.Bold + \
955        'Warning: did not find protocol buffer library and/or headers.\n' + \
956    '       Please install libprotobuf-dev for tracing support.' + \
957    termcap.Normal
958
959# Check for librt.
960have_posix_clock = \
961    conf.CheckLibWithHeader(None, 'time.h', 'C',
962                            'clock_nanosleep(0,0,NULL,NULL);') or \
963    conf.CheckLibWithHeader('rt', 'time.h', 'C',
964                            'clock_nanosleep(0,0,NULL,NULL);')
965
966have_posix_timers = \
967    conf.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
968                            'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
969
970if conf.CheckLib('tcmalloc'):
971    main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
972elif conf.CheckLib('tcmalloc_minimal'):
973    main.Append(CCFLAGS=main['TCMALLOC_CCFLAGS'])
974else:
975    print termcap.Yellow + termcap.Bold + \
976          "You can get a 12% performance improvement by installing tcmalloc "\
977          "(libgoogle-perftools-dev package on Ubuntu or RedHat)." + \
978          termcap.Normal
979
980if not have_posix_clock:
981    print "Can't find library for POSIX clocks."
982
983# Check for <fenv.h> (C99 FP environment control)
984have_fenv = conf.CheckHeader('fenv.h', '<>')
985if not have_fenv:
986    print "Warning: Header file <fenv.h> not found."
987    print "         This host has no IEEE FP rounding mode control."
988
989# Check if we should enable KVM-based hardware virtualization. The API
990# we rely on exists since version 2.6.36 of the kernel, but somehow
991# the KVM_API_VERSION does not reflect the change. We test for one of
992# the types as a fall back.
993have_kvm = conf.CheckHeader('linux/kvm.h', '<>') and \
994    conf.CheckTypeSize('struct kvm_xsave', '#include <linux/kvm.h>') != 0
995if not have_kvm:
996    print "Info: Compatible header file <linux/kvm.h> not found, " \
997        "disabling KVM support."
998
999# Check if the requested target ISA is compatible with the host
1000def is_isa_kvm_compatible(isa):
1001    isa_comp_table = {
1002        "arm" : ( "armv7l" ),
1003        "x86" : ( "x86_64" ),
1004        }
1005    try:
1006        import platform
1007        host_isa = platform.machine()
1008    except:
1009        print "Warning: Failed to determine host ISA."
1010        return False
1011
1012    return host_isa in isa_comp_table.get(isa, [])
1013
1014
1015# Check if the exclude_host attribute is available. We want this to
1016# get accurate instruction counts in KVM.
1017main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
1018    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
1019
1020
1021######################################################################
1022#
1023# Finish the configuration
1024#
1025main = conf.Finish()
1026
1027######################################################################
1028#
1029# Collect all non-global variables
1030#
1031
1032# Define the universe of supported ISAs
1033all_isa_list = [ ]
1034Export('all_isa_list')
1035
1036class CpuModel(object):
1037    '''The CpuModel class encapsulates everything the ISA parser needs to
1038    know about a particular CPU model.'''
1039
1040    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
1041    dict = {}
1042
1043    # Constructor.  Automatically adds models to CpuModel.dict.
1044    def __init__(self, name, default=False):
1045        self.name = name           # name of model
1046
1047        # This cpu is enabled by default
1048        self.default = default
1049
1050        # Add self to dict
1051        if name in CpuModel.dict:
1052            raise AttributeError, "CpuModel '%s' already registered" % name
1053        CpuModel.dict[name] = self
1054
1055Export('CpuModel')
1056
1057# Sticky variables get saved in the variables file so they persist from
1058# one invocation to the next (unless overridden, in which case the new
1059# value becomes sticky).
1060sticky_vars = Variables(args=ARGUMENTS)
1061Export('sticky_vars')
1062
1063# Sticky variables that should be exported
1064export_vars = []
1065Export('export_vars')
1066
1067# For Ruby
1068all_protocols = []
1069Export('all_protocols')
1070protocol_dirs = []
1071Export('protocol_dirs')
1072slicc_includes = []
1073Export('slicc_includes')
1074
1075# Walk the tree and execute all SConsopts scripts that wil add to the
1076# above variables
1077if GetOption('verbose'):
1078    print "Reading SConsopts"
1079for bdir in [ base_dir ] + extras_dir_list:
1080    if not isdir(bdir):
1081        print "Error: directory '%s' does not exist" % bdir
1082        Exit(1)
1083    for root, dirs, files in os.walk(bdir):
1084        if 'SConsopts' in files:
1085            if GetOption('verbose'):
1086                print "Reading", joinpath(root, 'SConsopts')
1087            SConscript(joinpath(root, 'SConsopts'))
1088
1089all_isa_list.sort()
1090
1091sticky_vars.AddVariables(
1092    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
1093    ListVariable('CPU_MODELS', 'CPU models',
1094                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
1095                 sorted(CpuModel.dict.keys())),
1096    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1097                 False),
1098    BoolVariable('SS_COMPATIBLE_FP',
1099                 'Make floating-point results compatible with SimpleScalar',
1100                 False),
1101    BoolVariable('USE_SSE2',
1102                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1103                 False),
1104    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
1105    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
1106    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1107    BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm),
1108    EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1109                  all_protocols),
1110    )
1111
1112# These variables get exported to #defines in config/*.hh (see src/SConscript).
1113export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
1114                'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF',
1115                'HAVE_PERF_ATTR_EXCLUDE_HOST']
1116
1117###################################################
1118#
1119# Define a SCons builder for configuration flag headers.
1120#
1121###################################################
1122
1123# This function generates a config header file that #defines the
1124# variable symbol to the current variable setting (0 or 1).  The source
1125# operands are the name of the variable and a Value node containing the
1126# value of the variable.
1127def build_config_file(target, source, env):
1128    (variable, value) = [s.get_contents() for s in source]
1129    f = file(str(target[0]), 'w')
1130    print >> f, '#define', variable, value
1131    f.close()
1132    return None
1133
1134# Combine the two functions into a scons Action object.
1135config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
1136
1137# The emitter munges the source & target node lists to reflect what
1138# we're really doing.
1139def config_emitter(target, source, env):
1140    # extract variable name from Builder arg
1141    variable = str(target[0])
1142    # True target is config header file
1143    target = joinpath('config', variable.lower() + '.hh')
1144    val = env[variable]
1145    if isinstance(val, bool):
1146        # Force value to 0/1
1147        val = int(val)
1148    elif isinstance(val, str):
1149        val = '"' + val + '"'
1150
1151    # Sources are variable name & value (packaged in SCons Value nodes)
1152    return ([target], [Value(variable), Value(val)])
1153
1154config_builder = Builder(emitter = config_emitter, action = config_action)
1155
1156main.Append(BUILDERS = { 'ConfigFile' : config_builder })
1157
1158# libelf build is shared across all configs in the build root.
1159main.SConscript('ext/libelf/SConscript',
1160                variant_dir = joinpath(build_root, 'libelf'))
1161
1162# gzstream build is shared across all configs in the build root.
1163main.SConscript('ext/gzstream/SConscript',
1164                variant_dir = joinpath(build_root, 'gzstream'))
1165
1166# libfdt build is shared across all configs in the build root.
1167main.SConscript('ext/libfdt/SConscript',
1168                variant_dir = joinpath(build_root, 'libfdt'))
1169
1170# fputils build is shared across all configs in the build root.
1171main.SConscript('ext/fputils/SConscript',
1172                variant_dir = joinpath(build_root, 'fputils'))
1173
1174# DRAMSim2 build is shared across all configs in the build root.
1175main.SConscript('ext/dramsim2/SConscript',
1176                variant_dir = joinpath(build_root, 'dramsim2'))
1177
1178###################################################
1179#
1180# This function is used to set up a directory with switching headers
1181#
1182###################################################
1183
1184main['ALL_ISA_LIST'] = all_isa_list
1185all_isa_deps = {}
1186def make_switching_dir(dname, switch_headers, env):
1187    # Generate the header.  target[0] is the full path of the output
1188    # header to generate.  'source' is a dummy variable, since we get the
1189    # list of ISAs from env['ALL_ISA_LIST'].
1190    def gen_switch_hdr(target, source, env):
1191        fname = str(target[0])
1192        isa = env['TARGET_ISA'].lower()
1193        try:
1194            f = open(fname, 'w')
1195            print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
1196            f.close()
1197        except IOError:
1198            print "Failed to create %s" % fname
1199            raise
1200
1201    # Build SCons Action object. 'varlist' specifies env vars that this
1202    # action depends on; when env['ALL_ISA_LIST'] changes these actions
1203    # should get re-executed.
1204    switch_hdr_action = MakeAction(gen_switch_hdr,
1205                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
1206
1207    # Instantiate actions for each header
1208    for hdr in switch_headers:
1209        env.Command(hdr, [], switch_hdr_action)
1210
1211    isa_target = Dir('.').up().name.lower().replace('_', '-')
1212    env['PHONY_BASE'] = '#'+isa_target
1213    all_isa_deps[isa_target] = None
1214
1215Export('make_switching_dir')
1216
1217# all-isas -> all-deps -> all-environs -> all_targets
1218main.Alias('#all-isas', [])
1219main.Alias('#all-deps', '#all-isas')
1220
1221# Dummy target to ensure all environments are created before telling
1222# SCons what to actually make (the command line arguments).  We attach
1223# them to the dependence graph after the environments are complete.
1224ORIG_BUILD_TARGETS = list(BUILD_TARGETS) # force a copy; gets closure to work.
1225def environsComplete(target, source, env):
1226    for t in ORIG_BUILD_TARGETS:
1227        main.Depends('#all-targets', t)
1228
1229# Each build/* switching_dir attaches its *-environs target to #all-environs.
1230main.Append(BUILDERS = {'CompleteEnvirons' :
1231                        Builder(action=MakeAction(environsComplete, None))})
1232main.CompleteEnvirons('#all-environs', [])
1233
1234def doNothing(**ignored): pass
1235main.Append(BUILDERS = {'Dummy': Builder(action=MakeAction(doNothing, None))})
1236
1237# The final target to which all the original targets ultimately get attached.
1238main.Dummy('#all-targets', '#all-environs')
1239BUILD_TARGETS[:] = ['#all-targets']
1240
1241###################################################
1242#
1243# Define build environments for selected configurations.
1244#
1245###################################################
1246
1247for variant_path in variant_paths:
1248    if not GetOption('silent'):
1249        print "Building in", variant_path
1250
1251    # Make a copy of the build-root environment to use for this config.
1252    env = main.Clone()
1253    env['BUILDDIR'] = variant_path
1254
1255    # variant_dir is the tail component of build path, and is used to
1256    # determine the build parameters (e.g., 'ALPHA_SE')
1257    (build_root, variant_dir) = splitpath(variant_path)
1258
1259    # Set env variables according to the build directory config.
1260    sticky_vars.files = []
1261    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1262    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1263    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1264    current_vars_file = joinpath(build_root, 'variables', variant_dir)
1265    if isfile(current_vars_file):
1266        sticky_vars.files.append(current_vars_file)
1267        if not GetOption('silent'):
1268            print "Using saved variables file %s" % current_vars_file
1269    else:
1270        # Build dir-specific variables file doesn't exist.
1271
1272        # Make sure the directory is there so we can create it later
1273        opt_dir = dirname(current_vars_file)
1274        if not isdir(opt_dir):
1275            mkdir(opt_dir)
1276
1277        # Get default build variables from source tree.  Variables are
1278        # normally determined by name of $VARIANT_DIR, but can be
1279        # overridden by '--default=' arg on command line.
1280        default = GetOption('default')
1281        opts_dir = joinpath(main.root.abspath, 'build_opts')
1282        if default:
1283            default_vars_files = [joinpath(build_root, 'variables', default),
1284                                  joinpath(opts_dir, default)]
1285        else:
1286            default_vars_files = [joinpath(opts_dir, variant_dir)]
1287        existing_files = filter(isfile, default_vars_files)
1288        if existing_files:
1289            default_vars_file = existing_files[0]
1290            sticky_vars.files.append(default_vars_file)
1291            print "Variables file %s not found,\n  using defaults in %s" \
1292                  % (current_vars_file, default_vars_file)
1293        else:
1294            print "Error: cannot find variables file %s or " \
1295                  "default file(s) %s" \
1296                  % (current_vars_file, ' or '.join(default_vars_files))
1297            Exit(1)
1298
1299    # Apply current variable settings to env
1300    sticky_vars.Update(env)
1301
1302    help_texts["local_vars"] += \
1303        "Build variables for %s:\n" % variant_dir \
1304                 + sticky_vars.GenerateHelpText(env)
1305
1306    # Process variable settings.
1307
1308    if not have_fenv and env['USE_FENV']:
1309        print "Warning: <fenv.h> not available; " \
1310              "forcing USE_FENV to False in", variant_dir + "."
1311        env['USE_FENV'] = False
1312
1313    if not env['USE_FENV']:
1314        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1315        print "         FP results may deviate slightly from other platforms."
1316
1317    if env['EFENCE']:
1318        env.Append(LIBS=['efence'])
1319
1320    if env['USE_KVM']:
1321        if not have_kvm:
1322            print "Warning: Can not enable KVM, host seems to lack KVM support"
1323            env['USE_KVM'] = False
1324        elif not have_posix_timers:
1325            print "Warning: Can not enable KVM, host seems to lack support " \
1326                "for POSIX timers"
1327            env['USE_KVM'] = False
1328        elif not is_isa_kvm_compatible(env['TARGET_ISA']):
1329            print "Info: KVM support disabled due to unsupported host and " \
1330                "target ISA combination"
1331            env['USE_KVM'] = False
1332
1333    # Warn about missing optional functionality
1334    if env['USE_KVM']:
1335        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1336            print "Warning: perf_event headers lack support for the " \
1337                "exclude_host attribute. KVM instruction counts will " \
1338                "be inaccurate."
1339
1340    # Save sticky variable settings back to current variables file
1341    sticky_vars.Save(current_vars_file, env)
1342
1343    if env['USE_SSE2']:
1344        env.Append(CCFLAGS=['-msse2'])
1345
1346    # The src/SConscript file sets up the build rules in 'env' according
1347    # to the configured variables.  It returns a list of environments,
1348    # one for each variant build (debug, opt, etc.)
1349    SConscript('src/SConscript', variant_dir = variant_path, exports = 'env')
1350
1351def pairwise(iterable):
1352    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
1353    a, b = itertools.tee(iterable)
1354    b.next()
1355    return itertools.izip(a, b)
1356
1357# Create false dependencies so SCons will parse ISAs, establish
1358# dependencies, and setup the build Environments serially. Either
1359# SCons (likely) and/or our SConscripts (possibly) cannot cope with -j
1360# greater than 1. It appears to be standard race condition stuff; it
1361# doesn't always fail, but usually, and the behaviors are different.
1362# Every time I tried to remove this, builds would fail in some
1363# creative new way. So, don't do that. You'll want to, though, because
1364# tests/SConscript takes a long time to make its Environments.
1365for t1, t2 in pairwise(sorted(all_isa_deps.iterkeys())):
1366    main.Depends('#%s-deps'     % t2, '#%s-deps'     % t1)
1367    main.Depends('#%s-environs' % t2, '#%s-environs' % t1)
1368
1369# base help text
1370Help('''
1371Usage: scons [scons options] [build variables] [target(s)]
1372
1373Extra scons options:
1374%(options)s
1375
1376Global build variables:
1377%(global_vars)s
1378
1379%(local_vars)s
1380''' % help_texts)
1381