SConstruct revision 8980
1# -*- mode:python -*-
2
3# Copyright (c) 2011 Advanced Micro Devices, Inc.
4# Copyright (c) 2009 The Hewlett-Packard Development Company
5# Copyright (c) 2004-2005 The Regents of The University of Michigan
6# All rights reserved.
7#
8# Redistribution and use in source and binary forms, with or without
9# modification, are permitted provided that the following conditions are
10# met: redistributions of source code must retain the above copyright
11# notice, this list of conditions and the following disclaimer;
12# redistributions in binary form must reproduce the above copyright
13# notice, this list of conditions and the following disclaimer in the
14# documentation and/or other materials provided with the distribution;
15# neither the name of the copyright holders nor the names of its
16# contributors may be used to endorse or promote products derived from
17# this software without specific prior written permission.
18#
19# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30#
31# Authors: Steve Reinhardt
32#          Nathan Binkert
33
34###################################################
35#
36# SCons top-level build description (SConstruct) file.
37#
38# While in this directory ('gem5'), just type 'scons' to build the default
39# configuration (see below), or type 'scons build/<CONFIG>/<binary>'
40# to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
41# the optimized full-system version).
42#
43# You can build gem5 in a different directory as long as there is a
44# 'build/<CONFIG>' somewhere along the target path.  The build system
45# expects that all configs under the same build directory are being
46# built for the same host system.
47#
48# Examples:
49#
50#   The following two commands are equivalent.  The '-u' option tells
51#   scons to search up the directory tree for this SConstruct file.
52#   % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
53#   % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
54#
55#   The following two commands are equivalent and demonstrate building
56#   in a directory outside of the source tree.  The '-C' option tells
57#   scons to chdir to the specified directory to find this SConstruct
58#   file.
59#   % cd <path-to-src>/gem5 ; scons /local/foo/build/ALPHA/gem5.debug
60#   % cd /local/foo/build/ALPHA; scons -C <path-to-src>/gem5 gem5.debug
61#
62# You can use 'scons -H' to print scons options.  If you're in this
63# 'gem5' directory (or use -u or -C to tell scons where to find this
64# file), you can use 'scons -h' to print all the gem5-specific build
65# options as well.
66#
67###################################################
68
69# Check for recent-enough Python and SCons versions.
70try:
71    # Really old versions of scons only take two options for the
72    # function, so check once without the revision and once with the
73    # revision, the first instance will fail for stuff other than
74    # 0.98, and the second will fail for 0.98.0
75    EnsureSConsVersion(0, 98)
76    EnsureSConsVersion(0, 98, 1)
77except SystemExit, e:
78    print """
79For more details, see:
80    http://gem5.org/Dependencies
81"""
82    raise
83
84# We ensure the python version early because we have stuff that
85# requires python 2.4
86try:
87    EnsurePythonVersion(2, 4)
88except SystemExit, e:
89    print """
90You can use a non-default installation of the Python interpreter by
91either (1) rearranging your PATH so that scons finds the non-default
92'python' first or (2) explicitly invoking an alternative interpreter
93on the scons script.
94
95For more details, see:
96    http://gem5.org/wiki/index.php/Using_a_non-default_Python_installation
97"""
98    raise
99
100# Global Python includes
101import os
102import re
103import subprocess
104import sys
105
106from os import mkdir, environ
107from os.path import abspath, basename, dirname, expanduser, normpath
108from os.path import exists,  isdir, isfile
109from os.path import join as joinpath, split as splitpath
110
111# SCons includes
112import SCons
113import SCons.Node
114
115extra_python_paths = [
116    Dir('src/python').srcnode().abspath, # gem5 includes
117    Dir('ext/ply').srcnode().abspath, # ply is used by several files
118    ]
119    
120sys.path[1:1] = extra_python_paths
121
122from m5.util import compareVersions, readCommand
123from m5.util.terminal import get_termcap
124
125help_texts = {
126    "options" : "",
127    "global_vars" : "",
128    "local_vars" : ""
129}
130
131Export("help_texts")
132
133
134# There's a bug in scons in that (1) by default, the help texts from
135# AddOption() are supposed to be displayed when you type 'scons -h'
136# and (2) you can override the help displayed by 'scons -h' using the
137# Help() function, but these two features are incompatible: once
138# you've overridden the help text using Help(), there's no way to get
139# at the help texts from AddOptions.  See:
140#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
141#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
142# This hack lets us extract the help text from AddOptions and
143# re-inject it via Help().  Ideally someday this bug will be fixed and
144# we can just use AddOption directly.
145def AddLocalOption(*args, **kwargs):
146    col_width = 30
147
148    help = "  " + ", ".join(args)
149    if "help" in kwargs:
150        length = len(help)
151        if length >= col_width:
152            help += "\n" + " " * col_width
153        else:
154            help += " " * (col_width - length)
155        help += kwargs["help"]
156    help_texts["options"] += help + "\n"
157
158    AddOption(*args, **kwargs)
159
160AddLocalOption('--colors', dest='use_colors', action='store_true',
161               help="Add color to abbreviated scons output")
162AddLocalOption('--no-colors', dest='use_colors', action='store_false',
163               help="Don't add color to abbreviated scons output")
164AddLocalOption('--default', dest='default', type='string', action='store',
165               help='Override which build_opts file to use for defaults')
166AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
167               help='Disable style checking hooks')
168AddLocalOption('--update-ref', dest='update_ref', action='store_true',
169               help='Update test reference outputs')
170AddLocalOption('--verbose', dest='verbose', action='store_true',
171               help='Print full tool command lines')
172
173termcap = get_termcap(GetOption('use_colors'))
174
175########################################################################
176#
177# Set up the main build environment.
178#
179########################################################################
180use_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH', 'PATH',
181                 'PYTHONPATH', 'RANLIB', 'SWIG' ])
182
183use_env = {}
184for key,val in os.environ.iteritems():
185    if key in use_vars or key.startswith("M5"):
186        use_env[key] = val
187
188main = Environment(ENV=use_env)
189main.Decider('MD5-timestamp')
190main.root = Dir(".")         # The current directory (where this file lives).
191main.srcdir = Dir("src")     # The source directory
192
193# add useful python code PYTHONPATH so it can be used by subprocesses
194# as well
195main.AppendENVPath('PYTHONPATH', extra_python_paths)
196
197########################################################################
198#
199# Mercurial Stuff.
200#
201# If the gem5 directory is a mercurial repository, we should do some
202# extra things.
203#
204########################################################################
205
206hgdir = main.root.Dir(".hg")
207
208mercurial_style_message = """
209You're missing the gem5 style hook, which automatically checks your code
210against the gem5 style rules on hg commit and qrefresh commands.  This
211script will now install the hook in your .hg/hgrc file.
212Press enter to continue, or ctrl-c to abort: """
213
214mercurial_style_hook = """
215# The following lines were automatically added by gem5/SConstruct
216# to provide the gem5 style-checking hooks
217[extensions]
218style = %s/util/style.py
219
220[hooks]
221pretxncommit.style = python:style.check_style
222pre-qrefresh.style = python:style.check_style
223# End of SConstruct additions
224
225""" % (main.root.abspath)
226
227mercurial_lib_not_found = """
228Mercurial libraries cannot be found, ignoring style hook.  If
229you are a gem5 developer, please fix this and run the style
230hook. It is important.
231"""
232
233# Check for style hook and prompt for installation if it's not there.
234# Skip this if --ignore-style was specified, there's no .hg dir to
235# install a hook in, or there's no interactive terminal to prompt.
236if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
237    style_hook = True
238    try:
239        from mercurial import ui
240        ui = ui.ui()
241        ui.readconfig(hgdir.File('hgrc').abspath)
242        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
243                     ui.config('hooks', 'pre-qrefresh.style', None)
244    except ImportError:
245        print mercurial_lib_not_found
246
247    if not style_hook:
248        print mercurial_style_message,
249        # continue unless user does ctrl-c/ctrl-d etc.
250        try:
251            raw_input()
252        except:
253            print "Input exception, exiting scons.\n"
254            sys.exit(1)
255        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
256        print "Adding style hook to", hgrc_path, "\n"
257        try:
258            hgrc = open(hgrc_path, 'a')
259            hgrc.write(mercurial_style_hook)
260            hgrc.close()
261        except:
262            print "Error updating", hgrc_path
263            sys.exit(1)
264
265
266###################################################
267#
268# Figure out which configurations to set up based on the path(s) of
269# the target(s).
270#
271###################################################
272
273# Find default configuration & binary.
274Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
275
276# helper function: find last occurrence of element in list
277def rfind(l, elt, offs = -1):
278    for i in range(len(l)+offs, 0, -1):
279        if l[i] == elt:
280            return i
281    raise ValueError, "element not found"
282
283# Take a list of paths (or SCons Nodes) and return a list with all
284# paths made absolute and ~-expanded.  Paths will be interpreted
285# relative to the launch directory unless a different root is provided
286def makePathListAbsolute(path_list, root=GetLaunchDir()):
287    return [abspath(joinpath(root, expanduser(str(p))))
288            for p in path_list]
289
290# Each target must have 'build' in the interior of the path; the
291# directory below this will determine the build parameters.  For
292# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
293# recognize that ALPHA_SE specifies the configuration because it
294# follow 'build' in the build path.
295
296# The funky assignment to "[:]" is needed to replace the list contents
297# in place rather than reassign the symbol to a new list, which
298# doesn't work (obviously!).
299BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
300
301# Generate a list of the unique build roots and configs that the
302# collected targets reference.
303variant_paths = []
304build_root = None
305for t in BUILD_TARGETS:
306    path_dirs = t.split('/')
307    try:
308        build_top = rfind(path_dirs, 'build', -2)
309    except:
310        print "Error: no non-leaf 'build' dir found on target path", t
311        Exit(1)
312    this_build_root = joinpath('/',*path_dirs[:build_top+1])
313    if not build_root:
314        build_root = this_build_root
315    else:
316        if this_build_root != build_root:
317            print "Error: build targets not under same build root\n"\
318                  "  %s\n  %s" % (build_root, this_build_root)
319            Exit(1)
320    variant_path = joinpath('/',*path_dirs[:build_top+2])
321    if variant_path not in variant_paths:
322        variant_paths.append(variant_path)
323
324# Make sure build_root exists (might not if this is the first build there)
325if not isdir(build_root):
326    mkdir(build_root)
327main['BUILDROOT'] = build_root
328
329Export('main')
330
331main.SConsignFile(joinpath(build_root, "sconsign"))
332
333# Default duplicate option is to use hard links, but this messes up
334# when you use emacs to edit a file in the target dir, as emacs moves
335# file to file~ then copies to file, breaking the link.  Symbolic
336# (soft) links work better.
337main.SetOption('duplicate', 'soft-copy')
338
339#
340# Set up global sticky variables... these are common to an entire build
341# tree (not specific to a particular build like ALPHA_SE)
342#
343
344global_vars_file = joinpath(build_root, 'variables.global')
345
346global_vars = Variables(global_vars_file, args=ARGUMENTS)
347
348global_vars.AddVariables(
349    ('CC', 'C compiler', environ.get('CC', main['CC'])),
350    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
351    ('SWIG', 'SWIG tool', environ.get('SWIG', main['SWIG'])),
352    ('BATCH', 'Use batch pool for build and tests', False),
353    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
354    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
355    ('EXTRAS', 'Add extra directories to the compilation', '')
356    )
357
358# Update main environment with values from ARGUMENTS & global_vars_file
359global_vars.Update(main)
360help_texts["global_vars"] += global_vars.GenerateHelpText(main)
361
362# Save sticky variable settings back to current variables file
363global_vars.Save(global_vars_file, main)
364
365# Parse EXTRAS variable to build list of all directories where we're
366# look for sources etc.  This list is exported as extras_dir_list.
367base_dir = main.srcdir.abspath
368if main['EXTRAS']:
369    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
370else:
371    extras_dir_list = []
372
373Export('base_dir')
374Export('extras_dir_list')
375
376# the ext directory should be on the #includes path
377main.Append(CPPPATH=[Dir('ext')])
378
379def strip_build_path(path, env):
380    path = str(path)
381    variant_base = env['BUILDROOT'] + os.path.sep
382    if path.startswith(variant_base):
383        path = path[len(variant_base):]
384    elif path.startswith('build/'):
385        path = path[6:]
386    return path
387
388# Generate a string of the form:
389#   common/path/prefix/src1, src2 -> tgt1, tgt2
390# to print while building.
391class Transform(object):
392    # all specific color settings should be here and nowhere else
393    tool_color = termcap.Normal
394    pfx_color = termcap.Yellow
395    srcs_color = termcap.Yellow + termcap.Bold
396    arrow_color = termcap.Blue + termcap.Bold
397    tgts_color = termcap.Yellow + termcap.Bold
398
399    def __init__(self, tool, max_sources=99):
400        self.format = self.tool_color + (" [%8s] " % tool) \
401                      + self.pfx_color + "%s" \
402                      + self.srcs_color + "%s" \
403                      + self.arrow_color + " -> " \
404                      + self.tgts_color + "%s" \
405                      + termcap.Normal
406        self.max_sources = max_sources
407
408    def __call__(self, target, source, env, for_signature=None):
409        # truncate source list according to max_sources param
410        source = source[0:self.max_sources]
411        def strip(f):
412            return strip_build_path(str(f), env)
413        if len(source) > 0:
414            srcs = map(strip, source)
415        else:
416            srcs = ['']
417        tgts = map(strip, target)
418        # surprisingly, os.path.commonprefix is a dumb char-by-char string
419        # operation that has nothing to do with paths.
420        com_pfx = os.path.commonprefix(srcs + tgts)
421        com_pfx_len = len(com_pfx)
422        if com_pfx:
423            # do some cleanup and sanity checking on common prefix
424            if com_pfx[-1] == ".":
425                # prefix matches all but file extension: ok
426                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
427                com_pfx = com_pfx[0:-1]
428            elif com_pfx[-1] == "/":
429                # common prefix is directory path: OK
430                pass
431            else:
432                src0_len = len(srcs[0])
433                tgt0_len = len(tgts[0])
434                if src0_len == com_pfx_len:
435                    # source is a substring of target, OK
436                    pass
437                elif tgt0_len == com_pfx_len:
438                    # target is a substring of source, need to back up to
439                    # avoid empty string on RHS of arrow
440                    sep_idx = com_pfx.rfind(".")
441                    if sep_idx != -1:
442                        com_pfx = com_pfx[0:sep_idx]
443                    else:
444                        com_pfx = ''
445                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
446                    # still splitting at file extension: ok
447                    pass
448                else:
449                    # probably a fluke; ignore it
450                    com_pfx = ''
451        # recalculate length in case com_pfx was modified
452        com_pfx_len = len(com_pfx)
453        def fmt(files):
454            f = map(lambda s: s[com_pfx_len:], files)
455            return ', '.join(f)
456        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
457
458Export('Transform')
459
460# enable the regression script to use the termcap
461main['TERMCAP'] = termcap
462
463if GetOption('verbose'):
464    def MakeAction(action, string, *args, **kwargs):
465        return Action(action, *args, **kwargs)
466else:
467    MakeAction = Action
468    main['CCCOMSTR']        = Transform("CC")
469    main['CXXCOMSTR']       = Transform("CXX")
470    main['ASCOMSTR']        = Transform("AS")
471    main['SWIGCOMSTR']      = Transform("SWIG")
472    main['ARCOMSTR']        = Transform("AR", 0)
473    main['LINKCOMSTR']      = Transform("LINK", 0)
474    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
475    main['M4COMSTR']        = Transform("M4")
476    main['SHCCCOMSTR']      = Transform("SHCC")
477    main['SHCXXCOMSTR']     = Transform("SHCXX")
478Export('MakeAction')
479
480CXX_version = readCommand([main['CXX'],'--version'], exception=False)
481CXX_V = readCommand([main['CXX'],'-V'], exception=False)
482
483main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
484main['SUNCC'] = CXX_V and CXX_V.find('Sun C++') >= 0
485main['ICC'] = CXX_V and CXX_V.find('Intel') >= 0
486main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
487if main['GCC'] + main['SUNCC'] + main['ICC'] + main['CLANG'] > 1:
488    print 'Error: How can we have two at the same time?'
489    Exit(1)
490
491# Set up default C++ compiler flags
492if main['GCC']:
493    main.Append(CCFLAGS=['-pipe'])
494    main.Append(CCFLAGS=['-fno-strict-aliasing'])
495    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
496    # Read the GCC version to check for versions with bugs
497    # Note CCVERSION doesn't work here because it is run with the CC
498    # before we override it from the command line
499    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
500    main['GCC_VERSION'] = gcc_version
501    if not compareVersions(gcc_version, '4.4.1') or \
502       not compareVersions(gcc_version, '4.4.2'):
503        print 'Info: Tree vectorizer in GCC 4.4.1 & 4.4.2 is buggy, disabling.'
504        main.Append(CCFLAGS=['-fno-tree-vectorize'])
505    if compareVersions(gcc_version, '4.6') >= 0:
506        main.Append(CXXFLAGS=['-std=c++0x'])
507elif main['ICC']:
508    pass #Fix me... add warning flags once we clean up icc warnings
509elif main['SUNCC']:
510    main.Append(CCFLAGS=['-Qoption ccfe'])
511    main.Append(CCFLAGS=['-features=gcc'])
512    main.Append(CCFLAGS=['-features=extensions'])
513    main.Append(CCFLAGS=['-library=stlport4'])
514    main.Append(CCFLAGS=['-xar'])
515    #main.Append(CCFLAGS=['-instances=semiexplicit'])
516elif main['CLANG']:
517    clang_version_re = re.compile(".* version (\d+\.\d+)")
518    clang_version_match = clang_version_re.match(CXX_version)
519    if (clang_version_match):
520        clang_version = clang_version_match.groups()[0]
521        if compareVersions(clang_version, "2.9") < 0:
522            print 'Error: clang version 2.9 or newer required.'
523            print '       Installed version:', clang_version
524            Exit(1)
525    else:
526        print 'Error: Unable to determine clang version.'
527        Exit(1)
528
529    main.Append(CCFLAGS=['-pipe'])
530    main.Append(CCFLAGS=['-fno-strict-aliasing'])
531    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
532    main.Append(CCFLAGS=['-Wno-tautological-compare'])
533    main.Append(CCFLAGS=['-Wno-self-assign'])
534    # Ruby makes frequent use of extraneous parantheses in the printing
535    # of if-statements
536    main.Append(CCFLAGS=['-Wno-parentheses'])
537
538    if compareVersions(clang_version, "3") >= 0:
539        main.Append(CXXFLAGS=['-std=c++0x'])
540else:
541    print 'Error: Don\'t know what compiler options to use for your compiler.'
542    print '       Please fix SConstruct and src/SConscript and try again.'
543    Exit(1)
544
545# Set up common yacc/bison flags (needed for Ruby)
546main['YACCFLAGS'] = '-d'
547main['YACCHXXFILESUFFIX'] = '.hh'
548
549# Do this after we save setting back, or else we'll tack on an
550# extra 'qdo' every time we run scons.
551if main['BATCH']:
552    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
553    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
554    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
555    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
556    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
557
558if sys.platform == 'cygwin':
559    # cygwin has some header file issues...
560    main.Append(CCFLAGS=["-Wno-uninitialized"])
561
562# Check for SWIG
563if not main.has_key('SWIG'):
564    print 'Error: SWIG utility not found.'
565    print '       Please install (see http://www.swig.org) and retry.'
566    Exit(1)
567
568# Check for appropriate SWIG version
569swig_version = readCommand(('swig', '-version'), exception='').split()
570# First 3 words should be "SWIG Version x.y.z"
571if len(swig_version) < 3 or \
572        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
573    print 'Error determining SWIG version.'
574    Exit(1)
575
576min_swig_version = '1.3.34'
577if compareVersions(swig_version[2], min_swig_version) < 0:
578    print 'Error: SWIG version', min_swig_version, 'or newer required.'
579    print '       Installed version:', swig_version[2]
580    Exit(1)
581
582# Set up SWIG flags & scanner
583swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
584main.Append(SWIGFLAGS=swig_flags)
585
586# filter out all existing swig scanners, they mess up the dependency
587# stuff for some reason
588scanners = []
589for scanner in main['SCANNERS']:
590    skeys = scanner.skeys
591    if skeys == '.i':
592        continue
593
594    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
595        continue
596
597    scanners.append(scanner)
598
599# add the new swig scanner that we like better
600from SCons.Scanner import ClassicCPP as CPPScanner
601swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
602scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
603
604# replace the scanners list that has what we want
605main['SCANNERS'] = scanners
606
607# Add a custom Check function to the Configure context so that we can
608# figure out if the compiler adds leading underscores to global
609# variables.  This is needed for the autogenerated asm files that we
610# use for embedding the python code.
611def CheckLeading(context):
612    context.Message("Checking for leading underscore in global variables...")
613    # 1) Define a global variable called x from asm so the C compiler
614    #    won't change the symbol at all.
615    # 2) Declare that variable.
616    # 3) Use the variable
617    #
618    # If the compiler prepends an underscore, this will successfully
619    # link because the external symbol 'x' will be called '_x' which
620    # was defined by the asm statement.  If the compiler does not
621    # prepend an underscore, this will not successfully link because
622    # '_x' will have been defined by assembly, while the C portion of
623    # the code will be trying to use 'x'
624    ret = context.TryLink('''
625        asm(".globl _x; _x: .byte 0");
626        extern int x;
627        int main() { return x; }
628        ''', extension=".c")
629    context.env.Append(LEADING_UNDERSCORE=ret)
630    context.Result(ret)
631    return ret
632
633# Platform-specific configuration.  Note again that we assume that all
634# builds under a given build root run on the same host platform.
635conf = Configure(main,
636                 conf_dir = joinpath(build_root, '.scons_config'),
637                 log_file = joinpath(build_root, 'scons_config.log'),
638                 custom_tests = { 'CheckLeading' : CheckLeading })
639
640# Check for leading underscores.  Don't really need to worry either
641# way so don't need to check the return code.
642conf.CheckLeading()
643
644# Check if we should compile a 64 bit binary on Mac OS X/Darwin
645try:
646    import platform
647    uname = platform.uname()
648    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
649        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
650            main.Append(CCFLAGS=['-arch', 'x86_64'])
651            main.Append(CFLAGS=['-arch', 'x86_64'])
652            main.Append(LINKFLAGS=['-arch', 'x86_64'])
653            main.Append(ASFLAGS=['-arch', 'x86_64'])
654except:
655    pass
656
657# Recent versions of scons substitute a "Null" object for Configure()
658# when configuration isn't necessary, e.g., if the "--help" option is
659# present.  Unfortuantely this Null object always returns false,
660# breaking all our configuration checks.  We replace it with our own
661# more optimistic null object that returns True instead.
662if not conf:
663    def NullCheck(*args, **kwargs):
664        return True
665
666    class NullConf:
667        def __init__(self, env):
668            self.env = env
669        def Finish(self):
670            return self.env
671        def __getattr__(self, mname):
672            return NullCheck
673
674    conf = NullConf(main)
675
676# Find Python include and library directories for embedding the
677# interpreter.  For consistency, we will use the same Python
678# installation used to run scons (and thus this script).  If you want
679# to link in an alternate version, see above for instructions on how
680# to invoke scons with a different copy of the Python interpreter.
681from distutils import sysconfig
682
683py_getvar = sysconfig.get_config_var
684
685py_debug = getattr(sys, 'pydebug', False)
686py_version = 'python' + py_getvar('VERSION') + (py_debug and "_d" or "")
687
688py_general_include = sysconfig.get_python_inc()
689py_platform_include = sysconfig.get_python_inc(plat_specific=True)
690py_includes = [ py_general_include ]
691if py_platform_include != py_general_include:
692    py_includes.append(py_platform_include)
693
694py_lib_path = [ py_getvar('LIBDIR') ]
695# add the prefix/lib/pythonX.Y/config dir, but only if there is no
696# shared library in prefix/lib/.
697if not py_getvar('Py_ENABLE_SHARED'):
698    py_lib_path.append(py_getvar('LIBPL'))
699
700py_libs = []
701for lib in py_getvar('LIBS').split() + py_getvar('SYSLIBS').split():
702    if not lib.startswith('-l'):
703        # Python requires some special flags to link (e.g. -framework
704        # common on OS X systems), assume appending preserves order
705        main.Append(LINKFLAGS=[lib])
706    else:
707        lib = lib[2:]
708        if lib not in py_libs:
709            py_libs.append(lib)
710py_libs.append(py_version)
711
712main.Append(CPPPATH=py_includes)
713main.Append(LIBPATH=py_lib_path)
714
715# Cache build files in the supplied directory.
716if main['M5_BUILD_CACHE']:
717    print 'Using build cache located at', main['M5_BUILD_CACHE']
718    CacheDir(main['M5_BUILD_CACHE'])
719
720
721# verify that this stuff works
722if not conf.CheckHeader('Python.h', '<>'):
723    print "Error: can't find Python.h header in", py_includes
724    Exit(1)
725
726for lib in py_libs:
727    if not conf.CheckLib(lib):
728        print "Error: can't find library %s required by python" % lib
729        Exit(1)
730
731# On Solaris you need to use libsocket for socket ops
732if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
733   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
734       print "Can't find library with socket calls (e.g. accept())"
735       Exit(1)
736
737# Check for zlib.  If the check passes, libz will be automatically
738# added to the LIBS environment variable.
739if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
740    print 'Error: did not find needed zlib compression library '\
741          'and/or zlib.h header file.'
742    print '       Please install zlib and try again.'
743    Exit(1)
744
745# Check for librt.
746have_posix_clock = \
747    conf.CheckLibWithHeader(None, 'time.h', 'C',
748                            'clock_nanosleep(0,0,NULL,NULL);') or \
749    conf.CheckLibWithHeader('rt', 'time.h', 'C',
750                            'clock_nanosleep(0,0,NULL,NULL);')
751
752if not have_posix_clock:
753    print "Can't find library for POSIX clocks."
754
755# Check for <fenv.h> (C99 FP environment control)
756have_fenv = conf.CheckHeader('fenv.h', '<>')
757if not have_fenv:
758    print "Warning: Header file <fenv.h> not found."
759    print "         This host has no IEEE FP rounding mode control."
760
761######################################################################
762#
763# Finish the configuration
764#
765main = conf.Finish()
766
767######################################################################
768#
769# Collect all non-global variables
770#
771
772# Define the universe of supported ISAs
773all_isa_list = [ ]
774Export('all_isa_list')
775
776class CpuModel(object):
777    '''The CpuModel class encapsulates everything the ISA parser needs to
778    know about a particular CPU model.'''
779
780    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
781    dict = {}
782    list = []
783    defaults = []
784
785    # Constructor.  Automatically adds models to CpuModel.dict.
786    def __init__(self, name, filename, includes, strings, default=False):
787        self.name = name           # name of model
788        self.filename = filename   # filename for output exec code
789        self.includes = includes   # include files needed in exec file
790        # The 'strings' dict holds all the per-CPU symbols we can
791        # substitute into templates etc.
792        self.strings = strings
793
794        # This cpu is enabled by default
795        self.default = default
796
797        # Add self to dict
798        if name in CpuModel.dict:
799            raise AttributeError, "CpuModel '%s' already registered" % name
800        CpuModel.dict[name] = self
801        CpuModel.list.append(name)
802
803Export('CpuModel')
804
805# Sticky variables get saved in the variables file so they persist from
806# one invocation to the next (unless overridden, in which case the new
807# value becomes sticky).
808sticky_vars = Variables(args=ARGUMENTS)
809Export('sticky_vars')
810
811# Sticky variables that should be exported
812export_vars = []
813Export('export_vars')
814
815# Walk the tree and execute all SConsopts scripts that wil add to the
816# above variables
817if not GetOption('verbose'):
818    print "Reading SConsopts"
819for bdir in [ base_dir ] + extras_dir_list:
820    if not isdir(bdir):
821        print "Error: directory '%s' does not exist" % bdir
822        Exit(1)
823    for root, dirs, files in os.walk(bdir):
824        if 'SConsopts' in files:
825            if GetOption('verbose'):
826                print "Reading", joinpath(root, 'SConsopts')
827            SConscript(joinpath(root, 'SConsopts'))
828
829all_isa_list.sort()
830
831sticky_vars.AddVariables(
832    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
833    ListVariable('CPU_MODELS', 'CPU models',
834                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
835                 sorted(CpuModel.list)),
836    BoolVariable('NO_FAST_ALLOC', 'Disable fast object allocator', False),
837    BoolVariable('FORCE_FAST_ALLOC',
838                 'Enable fast object allocator, even for gem5.debug', False),
839    BoolVariable('FAST_ALLOC_STATS', 'Enable fast object allocator statistics',
840                 False),
841    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
842                 False),
843    BoolVariable('SS_COMPATIBLE_FP',
844                 'Make floating-point results compatible with SimpleScalar',
845                 False),
846    BoolVariable('USE_SSE2',
847                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
848                 False),
849    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
850    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
851    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
852    )
853
854# These variables get exported to #defines in config/*.hh (see src/SConscript).
855export_vars += ['USE_FENV', 'NO_FAST_ALLOC', 'FORCE_FAST_ALLOC',
856                'FAST_ALLOC_STATS', 'SS_COMPATIBLE_FP',
857                'TARGET_ISA', 'CP_ANNOTATE', 'USE_POSIX_CLOCK' ]
858
859###################################################
860#
861# Define a SCons builder for configuration flag headers.
862#
863###################################################
864
865# This function generates a config header file that #defines the
866# variable symbol to the current variable setting (0 or 1).  The source
867# operands are the name of the variable and a Value node containing the
868# value of the variable.
869def build_config_file(target, source, env):
870    (variable, value) = [s.get_contents() for s in source]
871    f = file(str(target[0]), 'w')
872    print >> f, '#define', variable, value
873    f.close()
874    return None
875
876# Combine the two functions into a scons Action object.
877config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
878
879# The emitter munges the source & target node lists to reflect what
880# we're really doing.
881def config_emitter(target, source, env):
882    # extract variable name from Builder arg
883    variable = str(target[0])
884    # True target is config header file
885    target = joinpath('config', variable.lower() + '.hh')
886    val = env[variable]
887    if isinstance(val, bool):
888        # Force value to 0/1
889        val = int(val)
890    elif isinstance(val, str):
891        val = '"' + val + '"'
892
893    # Sources are variable name & value (packaged in SCons Value nodes)
894    return ([target], [Value(variable), Value(val)])
895
896config_builder = Builder(emitter = config_emitter, action = config_action)
897
898main.Append(BUILDERS = { 'ConfigFile' : config_builder })
899
900# libelf build is shared across all configs in the build root.
901main.SConscript('ext/libelf/SConscript',
902                variant_dir = joinpath(build_root, 'libelf'))
903
904# gzstream build is shared across all configs in the build root.
905main.SConscript('ext/gzstream/SConscript',
906                variant_dir = joinpath(build_root, 'gzstream'))
907
908###################################################
909#
910# This function is used to set up a directory with switching headers
911#
912###################################################
913
914main['ALL_ISA_LIST'] = all_isa_list
915def make_switching_dir(dname, switch_headers, env):
916    # Generate the header.  target[0] is the full path of the output
917    # header to generate.  'source' is a dummy variable, since we get the
918    # list of ISAs from env['ALL_ISA_LIST'].
919    def gen_switch_hdr(target, source, env):
920        fname = str(target[0])
921        f = open(fname, 'w')
922        isa = env['TARGET_ISA'].lower()
923        print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
924        f.close()
925
926    # Build SCons Action object. 'varlist' specifies env vars that this
927    # action depends on; when env['ALL_ISA_LIST'] changes these actions
928    # should get re-executed.
929    switch_hdr_action = MakeAction(gen_switch_hdr,
930                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
931
932    # Instantiate actions for each header
933    for hdr in switch_headers:
934        env.Command(hdr, [], switch_hdr_action)
935Export('make_switching_dir')
936
937###################################################
938#
939# Define build environments for selected configurations.
940#
941###################################################
942
943for variant_path in variant_paths:
944    print "Building in", variant_path
945
946    # Make a copy of the build-root environment to use for this config.
947    env = main.Clone()
948    env['BUILDDIR'] = variant_path
949
950    # variant_dir is the tail component of build path, and is used to
951    # determine the build parameters (e.g., 'ALPHA_SE')
952    (build_root, variant_dir) = splitpath(variant_path)
953
954    # Set env variables according to the build directory config.
955    sticky_vars.files = []
956    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
957    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
958    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
959    current_vars_file = joinpath(build_root, 'variables', variant_dir)
960    if isfile(current_vars_file):
961        sticky_vars.files.append(current_vars_file)
962        print "Using saved variables file %s" % current_vars_file
963    else:
964        # Build dir-specific variables file doesn't exist.
965
966        # Make sure the directory is there so we can create it later
967        opt_dir = dirname(current_vars_file)
968        if not isdir(opt_dir):
969            mkdir(opt_dir)
970
971        # Get default build variables from source tree.  Variables are
972        # normally determined by name of $VARIANT_DIR, but can be
973        # overridden by '--default=' arg on command line.
974        default = GetOption('default')
975        opts_dir = joinpath(main.root.abspath, 'build_opts')
976        if default:
977            default_vars_files = [joinpath(build_root, 'variables', default),
978                                  joinpath(opts_dir, default)]
979        else:
980            default_vars_files = [joinpath(opts_dir, variant_dir)]
981        existing_files = filter(isfile, default_vars_files)
982        if existing_files:
983            default_vars_file = existing_files[0]
984            sticky_vars.files.append(default_vars_file)
985            print "Variables file %s not found,\n  using defaults in %s" \
986                  % (current_vars_file, default_vars_file)
987        else:
988            print "Error: cannot find variables file %s or " \
989                  "default file(s) %s" \
990                  % (current_vars_file, ' or '.join(default_vars_files))
991            Exit(1)
992
993    # Apply current variable settings to env
994    sticky_vars.Update(env)
995
996    help_texts["local_vars"] += \
997        "Build variables for %s:\n" % variant_dir \
998                 + sticky_vars.GenerateHelpText(env)
999
1000    # Process variable settings.
1001
1002    if not have_fenv and env['USE_FENV']:
1003        print "Warning: <fenv.h> not available; " \
1004              "forcing USE_FENV to False in", variant_dir + "."
1005        env['USE_FENV'] = False
1006
1007    if not env['USE_FENV']:
1008        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1009        print "         FP results may deviate slightly from other platforms."
1010
1011    if env['EFENCE']:
1012        env.Append(LIBS=['efence'])
1013
1014    # Save sticky variable settings back to current variables file
1015    sticky_vars.Save(current_vars_file, env)
1016
1017    if env['USE_SSE2']:
1018        env.Append(CCFLAGS=['-msse2'])
1019
1020    # The src/SConscript file sets up the build rules in 'env' according
1021    # to the configured variables.  It returns a list of environments,
1022    # one for each variant build (debug, opt, etc.)
1023    envList = SConscript('src/SConscript', variant_dir = variant_path,
1024                         exports = 'env')
1025
1026    # Set up the regression tests for each build.
1027    for e in envList:
1028        SConscript('tests/SConscript',
1029                   variant_dir = joinpath(variant_path, 'tests', e.Label),
1030                   exports = { 'env' : e }, duplicate = False)
1031
1032# base help text
1033Help('''
1034Usage: scons [scons options] [build variables] [target(s)]
1035
1036Extra scons options:
1037%(options)s
1038
1039Global build variables:
1040%(global_vars)s
1041
1042%(local_vars)s
1043''' % help_texts)
1044