SConstruct revision 8946
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
123
124help_texts = {
125    "options" : "",
126    "global_vars" : "",
127    "local_vars" : ""
128}
129
130Export("help_texts")
131
132
133# There's a bug in scons in that (1) by default, the help texts from
134# AddOption() are supposed to be displayed when you type 'scons -h'
135# and (2) you can override the help displayed by 'scons -h' using the
136# Help() function, but these two features are incompatible: once
137# you've overridden the help text using Help(), there's no way to get
138# at the help texts from AddOptions.  See:
139#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
140#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
141# This hack lets us extract the help text from AddOptions and
142# re-inject it via Help().  Ideally someday this bug will be fixed and
143# we can just use AddOption directly.
144def AddLocalOption(*args, **kwargs):
145    col_width = 30
146
147    help = "  " + ", ".join(args)
148    if "help" in kwargs:
149        length = len(help)
150        if length >= col_width:
151            help += "\n" + " " * col_width
152        else:
153            help += " " * (col_width - length)
154        help += kwargs["help"]
155    help_texts["options"] += help + "\n"
156
157    AddOption(*args, **kwargs)
158
159AddLocalOption('--colors', dest='use_colors', action='store_true',
160               help="Add color to abbreviated scons output")
161AddLocalOption('--no-colors', dest='use_colors', action='store_false',
162               help="Don't add color to abbreviated scons output")
163AddLocalOption('--default', dest='default', type='string', action='store',
164               help='Override which build_opts file to use for defaults')
165AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
166               help='Disable style checking hooks')
167AddLocalOption('--update-ref', dest='update_ref', action='store_true',
168               help='Update test reference outputs')
169AddLocalOption('--verbose', dest='verbose', action='store_true',
170               help='Print full tool command lines')
171
172use_colors = GetOption('use_colors')
173if use_colors:
174    from m5.util.terminal import termcap
175elif use_colors is None:
176    # option unspecified; default behavior is to use colors iff isatty
177    from m5.util.terminal import tty_termcap as termcap
178else:
179    from m5.util.terminal import no_termcap as termcap
180
181########################################################################
182#
183# Set up the main build environment.
184#
185########################################################################
186use_vars = set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH', 'PATH',
187                 'PYTHONPATH', 'RANLIB' ])
188
189use_env = {}
190for key,val in os.environ.iteritems():
191    if key in use_vars or key.startswith("M5"):
192        use_env[key] = val
193
194main = Environment(ENV=use_env)
195main.Decider('MD5-timestamp')
196main.root = Dir(".")         # The current directory (where this file lives).
197main.srcdir = Dir("src")     # The source directory
198
199# add useful python code PYTHONPATH so it can be used by subprocesses
200# as well
201main.AppendENVPath('PYTHONPATH', extra_python_paths)
202
203########################################################################
204#
205# Mercurial Stuff.
206#
207# If the gem5 directory is a mercurial repository, we should do some
208# extra things.
209#
210########################################################################
211
212hgdir = main.root.Dir(".hg")
213
214mercurial_style_message = """
215You're missing the gem5 style hook, which automatically checks your code
216against the gem5 style rules on hg commit and qrefresh commands.  This
217script will now install the hook in your .hg/hgrc file.
218Press enter to continue, or ctrl-c to abort: """
219
220mercurial_style_hook = """
221# The following lines were automatically added by gem5/SConstruct
222# to provide the gem5 style-checking hooks
223[extensions]
224style = %s/util/style.py
225
226[hooks]
227pretxncommit.style = python:style.check_style
228pre-qrefresh.style = python:style.check_style
229# End of SConstruct additions
230
231""" % (main.root.abspath)
232
233mercurial_lib_not_found = """
234Mercurial libraries cannot be found, ignoring style hook.  If
235you are a gem5 developer, please fix this and run the style
236hook. It is important.
237"""
238
239# Check for style hook and prompt for installation if it's not there.
240# Skip this if --ignore-style was specified, there's no .hg dir to
241# install a hook in, or there's no interactive terminal to prompt.
242if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
243    style_hook = True
244    try:
245        from mercurial import ui
246        ui = ui.ui()
247        ui.readconfig(hgdir.File('hgrc').abspath)
248        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
249                     ui.config('hooks', 'pre-qrefresh.style', None)
250    except ImportError:
251        print mercurial_lib_not_found
252
253    if not style_hook:
254        print mercurial_style_message,
255        # continue unless user does ctrl-c/ctrl-d etc.
256        try:
257            raw_input()
258        except:
259            print "Input exception, exiting scons.\n"
260            sys.exit(1)
261        hgrc_path = '%s/.hg/hgrc' % main.root.abspath
262        print "Adding style hook to", hgrc_path, "\n"
263        try:
264            hgrc = open(hgrc_path, 'a')
265            hgrc.write(mercurial_style_hook)
266            hgrc.close()
267        except:
268            print "Error updating", hgrc_path
269            sys.exit(1)
270
271
272###################################################
273#
274# Figure out which configurations to set up based on the path(s) of
275# the target(s).
276#
277###################################################
278
279# Find default configuration & binary.
280Default(environ.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
281
282# helper function: find last occurrence of element in list
283def rfind(l, elt, offs = -1):
284    for i in range(len(l)+offs, 0, -1):
285        if l[i] == elt:
286            return i
287    raise ValueError, "element not found"
288
289# Take a list of paths (or SCons Nodes) and return a list with all
290# paths made absolute and ~-expanded.  Paths will be interpreted
291# relative to the launch directory unless a different root is provided
292def makePathListAbsolute(path_list, root=GetLaunchDir()):
293    return [abspath(joinpath(root, expanduser(str(p))))
294            for p in path_list]
295
296# Each target must have 'build' in the interior of the path; the
297# directory below this will determine the build parameters.  For
298# example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
299# recognize that ALPHA_SE specifies the configuration because it
300# follow 'build' in the build path.
301
302# The funky assignment to "[:]" is needed to replace the list contents
303# in place rather than reassign the symbol to a new list, which
304# doesn't work (obviously!).
305BUILD_TARGETS[:] = makePathListAbsolute(BUILD_TARGETS)
306
307# Generate a list of the unique build roots and configs that the
308# collected targets reference.
309variant_paths = []
310build_root = None
311for t in BUILD_TARGETS:
312    path_dirs = t.split('/')
313    try:
314        build_top = rfind(path_dirs, 'build', -2)
315    except:
316        print "Error: no non-leaf 'build' dir found on target path", t
317        Exit(1)
318    this_build_root = joinpath('/',*path_dirs[:build_top+1])
319    if not build_root:
320        build_root = this_build_root
321    else:
322        if this_build_root != build_root:
323            print "Error: build targets not under same build root\n"\
324                  "  %s\n  %s" % (build_root, this_build_root)
325            Exit(1)
326    variant_path = joinpath('/',*path_dirs[:build_top+2])
327    if variant_path not in variant_paths:
328        variant_paths.append(variant_path)
329
330# Make sure build_root exists (might not if this is the first build there)
331if not isdir(build_root):
332    mkdir(build_root)
333main['BUILDROOT'] = build_root
334
335Export('main')
336
337main.SConsignFile(joinpath(build_root, "sconsign"))
338
339# Default duplicate option is to use hard links, but this messes up
340# when you use emacs to edit a file in the target dir, as emacs moves
341# file to file~ then copies to file, breaking the link.  Symbolic
342# (soft) links work better.
343main.SetOption('duplicate', 'soft-copy')
344
345#
346# Set up global sticky variables... these are common to an entire build
347# tree (not specific to a particular build like ALPHA_SE)
348#
349
350global_vars_file = joinpath(build_root, 'variables.global')
351
352global_vars = Variables(global_vars_file, args=ARGUMENTS)
353
354global_vars.AddVariables(
355    ('CC', 'C compiler', environ.get('CC', main['CC'])),
356    ('CXX', 'C++ compiler', environ.get('CXX', main['CXX'])),
357    ('BATCH', 'Use batch pool for build and tests', False),
358    ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
359    ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
360    ('EXTRAS', 'Add extra directories to the compilation', '')
361    )
362
363# Update main environment with values from ARGUMENTS & global_vars_file
364global_vars.Update(main)
365help_texts["global_vars"] += global_vars.GenerateHelpText(main)
366
367# Save sticky variable settings back to current variables file
368global_vars.Save(global_vars_file, main)
369
370# Parse EXTRAS variable to build list of all directories where we're
371# look for sources etc.  This list is exported as extras_dir_list.
372base_dir = main.srcdir.abspath
373if main['EXTRAS']:
374    extras_dir_list = makePathListAbsolute(main['EXTRAS'].split(':'))
375else:
376    extras_dir_list = []
377
378Export('base_dir')
379Export('extras_dir_list')
380
381# the ext directory should be on the #includes path
382main.Append(CPPPATH=[Dir('ext')])
383
384def strip_build_path(path, env):
385    path = str(path)
386    variant_base = env['BUILDROOT'] + os.path.sep
387    if path.startswith(variant_base):
388        path = path[len(variant_base):]
389    elif path.startswith('build/'):
390        path = path[6:]
391    return path
392
393# Generate a string of the form:
394#   common/path/prefix/src1, src2 -> tgt1, tgt2
395# to print while building.
396class Transform(object):
397    # all specific color settings should be here and nowhere else
398    tool_color = termcap.Normal
399    pfx_color = termcap.Yellow
400    srcs_color = termcap.Yellow + termcap.Bold
401    arrow_color = termcap.Blue + termcap.Bold
402    tgts_color = termcap.Yellow + termcap.Bold
403
404    def __init__(self, tool, max_sources=99):
405        self.format = self.tool_color + (" [%8s] " % tool) \
406                      + self.pfx_color + "%s" \
407                      + self.srcs_color + "%s" \
408                      + self.arrow_color + " -> " \
409                      + self.tgts_color + "%s" \
410                      + termcap.Normal
411        self.max_sources = max_sources
412
413    def __call__(self, target, source, env, for_signature=None):
414        # truncate source list according to max_sources param
415        source = source[0:self.max_sources]
416        def strip(f):
417            return strip_build_path(str(f), env)
418        if len(source) > 0:
419            srcs = map(strip, source)
420        else:
421            srcs = ['']
422        tgts = map(strip, target)
423        # surprisingly, os.path.commonprefix is a dumb char-by-char string
424        # operation that has nothing to do with paths.
425        com_pfx = os.path.commonprefix(srcs + tgts)
426        com_pfx_len = len(com_pfx)
427        if com_pfx:
428            # do some cleanup and sanity checking on common prefix
429            if com_pfx[-1] == ".":
430                # prefix matches all but file extension: ok
431                # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
432                com_pfx = com_pfx[0:-1]
433            elif com_pfx[-1] == "/":
434                # common prefix is directory path: OK
435                pass
436            else:
437                src0_len = len(srcs[0])
438                tgt0_len = len(tgts[0])
439                if src0_len == com_pfx_len:
440                    # source is a substring of target, OK
441                    pass
442                elif tgt0_len == com_pfx_len:
443                    # target is a substring of source, need to back up to
444                    # avoid empty string on RHS of arrow
445                    sep_idx = com_pfx.rfind(".")
446                    if sep_idx != -1:
447                        com_pfx = com_pfx[0:sep_idx]
448                    else:
449                        com_pfx = ''
450                elif src0_len > com_pfx_len and srcs[0][com_pfx_len] == ".":
451                    # still splitting at file extension: ok
452                    pass
453                else:
454                    # probably a fluke; ignore it
455                    com_pfx = ''
456        # recalculate length in case com_pfx was modified
457        com_pfx_len = len(com_pfx)
458        def fmt(files):
459            f = map(lambda s: s[com_pfx_len:], files)
460            return ', '.join(f)
461        return self.format % (com_pfx, fmt(srcs), fmt(tgts))
462
463Export('Transform')
464
465
466if GetOption('verbose'):
467    def MakeAction(action, string, *args, **kwargs):
468        return Action(action, *args, **kwargs)
469else:
470    MakeAction = Action
471    main['CCCOMSTR']        = Transform("CC")
472    main['CXXCOMSTR']       = Transform("CXX")
473    main['ASCOMSTR']        = Transform("AS")
474    main['SWIGCOMSTR']      = Transform("SWIG")
475    main['ARCOMSTR']        = Transform("AR", 0)
476    main['LINKCOMSTR']      = Transform("LINK", 0)
477    main['RANLIBCOMSTR']    = Transform("RANLIB", 0)
478    main['M4COMSTR']        = Transform("M4")
479    main['SHCCCOMSTR']      = Transform("SHCC")
480    main['SHCXXCOMSTR']     = Transform("SHCXX")
481Export('MakeAction')
482
483CXX_version = readCommand([main['CXX'],'--version'], exception=False)
484CXX_V = readCommand([main['CXX'],'-V'], exception=False)
485
486main['GCC'] = CXX_version and CXX_version.find('g++') >= 0
487main['SUNCC'] = CXX_V and CXX_V.find('Sun C++') >= 0
488main['ICC'] = CXX_V and CXX_V.find('Intel') >= 0
489main['CLANG'] = CXX_version and CXX_version.find('clang') >= 0
490if main['GCC'] + main['SUNCC'] + main['ICC'] + main['CLANG'] > 1:
491    print 'Error: How can we have two at the same time?'
492    Exit(1)
493
494# Set up default C++ compiler flags
495if main['GCC']:
496    main.Append(CCFLAGS=['-pipe'])
497    main.Append(CCFLAGS=['-fno-strict-aliasing'])
498    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
499    # Read the GCC version to check for versions with bugs
500    # Note CCVERSION doesn't work here because it is run with the CC
501    # before we override it from the command line
502    gcc_version = readCommand([main['CXX'], '-dumpversion'], exception=False)
503    main['GCC_VERSION'] = gcc_version
504    if not compareVersions(gcc_version, '4.4.1') or \
505       not compareVersions(gcc_version, '4.4.2'):
506        print 'Info: Tree vectorizer in GCC 4.4.1 & 4.4.2 is buggy, disabling.'
507        main.Append(CCFLAGS=['-fno-tree-vectorize'])
508    if compareVersions(gcc_version, '4.6') >= 0:
509        main.Append(CXXFLAGS=['-std=c++0x'])
510elif main['ICC']:
511    pass #Fix me... add warning flags once we clean up icc warnings
512elif main['SUNCC']:
513    main.Append(CCFLAGS=['-Qoption ccfe'])
514    main.Append(CCFLAGS=['-features=gcc'])
515    main.Append(CCFLAGS=['-features=extensions'])
516    main.Append(CCFLAGS=['-library=stlport4'])
517    main.Append(CCFLAGS=['-xar'])
518    #main.Append(CCFLAGS=['-instances=semiexplicit'])
519elif main['CLANG']:
520    clang_version_re = re.compile(".* version (\d+\.\d+)")
521    clang_version_match = clang_version_re.match(CXX_version)
522    if (clang_version_match):
523        clang_version = clang_version_match.groups()[0]
524        if compareVersions(clang_version, "2.9") < 0:
525            print 'Error: clang version 2.9 or newer required.'
526            print '       Installed version:', clang_version
527            Exit(1)
528    else:
529        print 'Error: Unable to determine clang version.'
530        Exit(1)
531
532    main.Append(CCFLAGS=['-pipe'])
533    main.Append(CCFLAGS=['-fno-strict-aliasing'])
534    main.Append(CCFLAGS=['-Wall', '-Wno-sign-compare', '-Wundef'])
535    main.Append(CCFLAGS=['-Wno-tautological-compare'])
536    main.Append(CCFLAGS=['-Wno-self-assign'])
537    # Ruby makes frequent use of extraneous parantheses in the printing
538    # of if-statements
539    main.Append(CCFLAGS=['-Wno-parentheses'])
540
541    if compareVersions(clang_version, "3") >= 0:
542        main.Append(CXXFLAGS=['-std=c++0x'])
543else:
544    print 'Error: Don\'t know what compiler options to use for your compiler.'
545    print '       Please fix SConstruct and src/SConscript and try again.'
546    Exit(1)
547
548# Set up common yacc/bison flags (needed for Ruby)
549main['YACCFLAGS'] = '-d'
550main['YACCHXXFILESUFFIX'] = '.hh'
551
552# Do this after we save setting back, or else we'll tack on an
553# extra 'qdo' every time we run scons.
554if main['BATCH']:
555    main['CC']     = main['BATCH_CMD'] + ' ' + main['CC']
556    main['CXX']    = main['BATCH_CMD'] + ' ' + main['CXX']
557    main['AS']     = main['BATCH_CMD'] + ' ' + main['AS']
558    main['AR']     = main['BATCH_CMD'] + ' ' + main['AR']
559    main['RANLIB'] = main['BATCH_CMD'] + ' ' + main['RANLIB']
560
561if sys.platform == 'cygwin':
562    # cygwin has some header file issues...
563    main.Append(CCFLAGS=["-Wno-uninitialized"])
564
565# Check for SWIG
566if not main.has_key('SWIG'):
567    print 'Error: SWIG utility not found.'
568    print '       Please install (see http://www.swig.org) and retry.'
569    Exit(1)
570
571# Check for appropriate SWIG version
572swig_version = readCommand(('swig', '-version'), exception='').split()
573# First 3 words should be "SWIG Version x.y.z"
574if len(swig_version) < 3 or \
575        swig_version[0] != 'SWIG' or swig_version[1] != 'Version':
576    print 'Error determining SWIG version.'
577    Exit(1)
578
579min_swig_version = '1.3.28'
580if compareVersions(swig_version[2], min_swig_version) < 0:
581    print 'Error: SWIG version', min_swig_version, 'or newer required.'
582    print '       Installed version:', swig_version[2]
583    Exit(1)
584
585# Set up SWIG flags & scanner
586swig_flags=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
587main.Append(SWIGFLAGS=swig_flags)
588
589# filter out all existing swig scanners, they mess up the dependency
590# stuff for some reason
591scanners = []
592for scanner in main['SCANNERS']:
593    skeys = scanner.skeys
594    if skeys == '.i':
595        continue
596
597    if isinstance(skeys, (list, tuple)) and '.i' in skeys:
598        continue
599
600    scanners.append(scanner)
601
602# add the new swig scanner that we like better
603from SCons.Scanner import ClassicCPP as CPPScanner
604swig_inc_re = '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
605scanners.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re))
606
607# replace the scanners list that has what we want
608main['SCANNERS'] = scanners
609
610# Add a custom Check function to the Configure context so that we can
611# figure out if the compiler adds leading underscores to global
612# variables.  This is needed for the autogenerated asm files that we
613# use for embedding the python code.
614def CheckLeading(context):
615    context.Message("Checking for leading underscore in global variables...")
616    # 1) Define a global variable called x from asm so the C compiler
617    #    won't change the symbol at all.
618    # 2) Declare that variable.
619    # 3) Use the variable
620    #
621    # If the compiler prepends an underscore, this will successfully
622    # link because the external symbol 'x' will be called '_x' which
623    # was defined by the asm statement.  If the compiler does not
624    # prepend an underscore, this will not successfully link because
625    # '_x' will have been defined by assembly, while the C portion of
626    # the code will be trying to use 'x'
627    ret = context.TryLink('''
628        asm(".globl _x; _x: .byte 0");
629        extern int x;
630        int main() { return x; }
631        ''', extension=".c")
632    context.env.Append(LEADING_UNDERSCORE=ret)
633    context.Result(ret)
634    return ret
635
636# Platform-specific configuration.  Note again that we assume that all
637# builds under a given build root run on the same host platform.
638conf = Configure(main,
639                 conf_dir = joinpath(build_root, '.scons_config'),
640                 log_file = joinpath(build_root, 'scons_config.log'),
641                 custom_tests = { 'CheckLeading' : CheckLeading })
642
643# Check for leading underscores.  Don't really need to worry either
644# way so don't need to check the return code.
645conf.CheckLeading()
646
647# Check if we should compile a 64 bit binary on Mac OS X/Darwin
648try:
649    import platform
650    uname = platform.uname()
651    if uname[0] == 'Darwin' and compareVersions(uname[2], '9.0.0') >= 0:
652        if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
653            main.Append(CCFLAGS=['-arch', 'x86_64'])
654            main.Append(CFLAGS=['-arch', 'x86_64'])
655            main.Append(LINKFLAGS=['-arch', 'x86_64'])
656            main.Append(ASFLAGS=['-arch', 'x86_64'])
657except:
658    pass
659
660# Recent versions of scons substitute a "Null" object for Configure()
661# when configuration isn't necessary, e.g., if the "--help" option is
662# present.  Unfortuantely this Null object always returns false,
663# breaking all our configuration checks.  We replace it with our own
664# more optimistic null object that returns True instead.
665if not conf:
666    def NullCheck(*args, **kwargs):
667        return True
668
669    class NullConf:
670        def __init__(self, env):
671            self.env = env
672        def Finish(self):
673            return self.env
674        def __getattr__(self, mname):
675            return NullCheck
676
677    conf = NullConf(main)
678
679# Find Python include and library directories for embedding the
680# interpreter.  For consistency, we will use the same Python
681# installation used to run scons (and thus this script).  If you want
682# to link in an alternate version, see above for instructions on how
683# to invoke scons with a different copy of the Python interpreter.
684from distutils import sysconfig
685
686py_getvar = sysconfig.get_config_var
687
688py_debug = getattr(sys, 'pydebug', False)
689py_version = 'python' + py_getvar('VERSION') + (py_debug and "_d" or "")
690
691py_general_include = sysconfig.get_python_inc()
692py_platform_include = sysconfig.get_python_inc(plat_specific=True)
693py_includes = [ py_general_include ]
694if py_platform_include != py_general_include:
695    py_includes.append(py_platform_include)
696
697py_lib_path = [ py_getvar('LIBDIR') ]
698# add the prefix/lib/pythonX.Y/config dir, but only if there is no
699# shared library in prefix/lib/.
700if not py_getvar('Py_ENABLE_SHARED'):
701    py_lib_path.append(py_getvar('LIBPL'))
702
703py_libs = []
704for lib in py_getvar('LIBS').split() + py_getvar('SYSLIBS').split():
705    if not lib.startswith('-l'):
706        # Python requires some special flags to link (e.g. -framework
707        # common on OS X systems), assume appending preserves order
708        main.Append(LINKFLAGS=[lib])
709    else:
710        lib = lib[2:]
711        if lib not in py_libs:
712            py_libs.append(lib)
713py_libs.append(py_version)
714
715main.Append(CPPPATH=py_includes)
716main.Append(LIBPATH=py_lib_path)
717
718# Cache build files in the supplied directory.
719if main['M5_BUILD_CACHE']:
720    print 'Using build cache located at', main['M5_BUILD_CACHE']
721    CacheDir(main['M5_BUILD_CACHE'])
722
723
724# verify that this stuff works
725if not conf.CheckHeader('Python.h', '<>'):
726    print "Error: can't find Python.h header in", py_includes
727    Exit(1)
728
729for lib in py_libs:
730    if not conf.CheckLib(lib):
731        print "Error: can't find library %s required by python" % lib
732        Exit(1)
733
734# On Solaris you need to use libsocket for socket ops
735if not conf.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
736   if not conf.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
737       print "Can't find library with socket calls (e.g. accept())"
738       Exit(1)
739
740# Check for zlib.  If the check passes, libz will be automatically
741# added to the LIBS environment variable.
742if not conf.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
743    print 'Error: did not find needed zlib compression library '\
744          'and/or zlib.h header file.'
745    print '       Please install zlib and try again.'
746    Exit(1)
747
748# Check for librt.
749have_posix_clock = \
750    conf.CheckLibWithHeader(None, 'time.h', 'C',
751                            'clock_nanosleep(0,0,NULL,NULL);') or \
752    conf.CheckLibWithHeader('rt', 'time.h', 'C',
753                            'clock_nanosleep(0,0,NULL,NULL);')
754
755if not have_posix_clock:
756    print "Can't find library for POSIX clocks."
757
758# Check for <fenv.h> (C99 FP environment control)
759have_fenv = conf.CheckHeader('fenv.h', '<>')
760if not have_fenv:
761    print "Warning: Header file <fenv.h> not found."
762    print "         This host has no IEEE FP rounding mode control."
763
764######################################################################
765#
766# Finish the configuration
767#
768main = conf.Finish()
769
770######################################################################
771#
772# Collect all non-global variables
773#
774
775# Define the universe of supported ISAs
776all_isa_list = [ ]
777Export('all_isa_list')
778
779class CpuModel(object):
780    '''The CpuModel class encapsulates everything the ISA parser needs to
781    know about a particular CPU model.'''
782
783    # Dict of available CPU model objects.  Accessible as CpuModel.dict.
784    dict = {}
785    list = []
786    defaults = []
787
788    # Constructor.  Automatically adds models to CpuModel.dict.
789    def __init__(self, name, filename, includes, strings, default=False):
790        self.name = name           # name of model
791        self.filename = filename   # filename for output exec code
792        self.includes = includes   # include files needed in exec file
793        # The 'strings' dict holds all the per-CPU symbols we can
794        # substitute into templates etc.
795        self.strings = strings
796
797        # This cpu is enabled by default
798        self.default = default
799
800        # Add self to dict
801        if name in CpuModel.dict:
802            raise AttributeError, "CpuModel '%s' already registered" % name
803        CpuModel.dict[name] = self
804        CpuModel.list.append(name)
805
806Export('CpuModel')
807
808# Sticky variables get saved in the variables file so they persist from
809# one invocation to the next (unless overridden, in which case the new
810# value becomes sticky).
811sticky_vars = Variables(args=ARGUMENTS)
812Export('sticky_vars')
813
814# Sticky variables that should be exported
815export_vars = []
816Export('export_vars')
817
818# Walk the tree and execute all SConsopts scripts that wil add to the
819# above variables
820if not GetOption('verbose'):
821    print "Reading SConsopts"
822for bdir in [ base_dir ] + extras_dir_list:
823    if not isdir(bdir):
824        print "Error: directory '%s' does not exist" % bdir
825        Exit(1)
826    for root, dirs, files in os.walk(bdir):
827        if 'SConsopts' in files:
828            if GetOption('verbose'):
829                print "Reading", joinpath(root, 'SConsopts')
830            SConscript(joinpath(root, 'SConsopts'))
831
832all_isa_list.sort()
833
834sticky_vars.AddVariables(
835    EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list),
836    ListVariable('CPU_MODELS', 'CPU models',
837                 sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
838                 sorted(CpuModel.list)),
839    BoolVariable('NO_FAST_ALLOC', 'Disable fast object allocator', False),
840    BoolVariable('FORCE_FAST_ALLOC',
841                 'Enable fast object allocator, even for gem5.debug', False),
842    BoolVariable('FAST_ALLOC_STATS', 'Enable fast object allocator statistics',
843                 False),
844    BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
845                 False),
846    BoolVariable('SS_COMPATIBLE_FP',
847                 'Make floating-point results compatible with SimpleScalar',
848                 False),
849    BoolVariable('USE_SSE2',
850                 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
851                 False),
852    BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock),
853    BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv),
854    BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
855    )
856
857# These variables get exported to #defines in config/*.hh (see src/SConscript).
858export_vars += ['USE_FENV', 'NO_FAST_ALLOC', 'FORCE_FAST_ALLOC',
859                'FAST_ALLOC_STATS', 'SS_COMPATIBLE_FP',
860                'TARGET_ISA', 'CP_ANNOTATE', 'USE_POSIX_CLOCK' ]
861
862###################################################
863#
864# Define a SCons builder for configuration flag headers.
865#
866###################################################
867
868# This function generates a config header file that #defines the
869# variable symbol to the current variable setting (0 or 1).  The source
870# operands are the name of the variable and a Value node containing the
871# value of the variable.
872def build_config_file(target, source, env):
873    (variable, value) = [s.get_contents() for s in source]
874    f = file(str(target[0]), 'w')
875    print >> f, '#define', variable, value
876    f.close()
877    return None
878
879# Combine the two functions into a scons Action object.
880config_action = MakeAction(build_config_file, Transform("CONFIG H", 2))
881
882# The emitter munges the source & target node lists to reflect what
883# we're really doing.
884def config_emitter(target, source, env):
885    # extract variable name from Builder arg
886    variable = str(target[0])
887    # True target is config header file
888    target = joinpath('config', variable.lower() + '.hh')
889    val = env[variable]
890    if isinstance(val, bool):
891        # Force value to 0/1
892        val = int(val)
893    elif isinstance(val, str):
894        val = '"' + val + '"'
895
896    # Sources are variable name & value (packaged in SCons Value nodes)
897    return ([target], [Value(variable), Value(val)])
898
899config_builder = Builder(emitter = config_emitter, action = config_action)
900
901main.Append(BUILDERS = { 'ConfigFile' : config_builder })
902
903# libelf build is shared across all configs in the build root.
904main.SConscript('ext/libelf/SConscript',
905                variant_dir = joinpath(build_root, 'libelf'))
906
907# gzstream build is shared across all configs in the build root.
908main.SConscript('ext/gzstream/SConscript',
909                variant_dir = joinpath(build_root, 'gzstream'))
910
911###################################################
912#
913# This function is used to set up a directory with switching headers
914#
915###################################################
916
917main['ALL_ISA_LIST'] = all_isa_list
918def make_switching_dir(dname, switch_headers, env):
919    # Generate the header.  target[0] is the full path of the output
920    # header to generate.  'source' is a dummy variable, since we get the
921    # list of ISAs from env['ALL_ISA_LIST'].
922    def gen_switch_hdr(target, source, env):
923        fname = str(target[0])
924        f = open(fname, 'w')
925        isa = env['TARGET_ISA'].lower()
926        print >>f, '#include "%s/%s/%s"' % (dname, isa, basename(fname))
927        f.close()
928
929    # Build SCons Action object. 'varlist' specifies env vars that this
930    # action depends on; when env['ALL_ISA_LIST'] changes these actions
931    # should get re-executed.
932    switch_hdr_action = MakeAction(gen_switch_hdr,
933                          Transform("GENERATE"), varlist=['ALL_ISA_LIST'])
934
935    # Instantiate actions for each header
936    for hdr in switch_headers:
937        env.Command(hdr, [], switch_hdr_action)
938Export('make_switching_dir')
939
940###################################################
941#
942# Define build environments for selected configurations.
943#
944###################################################
945
946for variant_path in variant_paths:
947    print "Building in", variant_path
948
949    # Make a copy of the build-root environment to use for this config.
950    env = main.Clone()
951    env['BUILDDIR'] = variant_path
952
953    # variant_dir is the tail component of build path, and is used to
954    # determine the build parameters (e.g., 'ALPHA_SE')
955    (build_root, variant_dir) = splitpath(variant_path)
956
957    # Set env variables according to the build directory config.
958    sticky_vars.files = []
959    # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
960    # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
961    # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
962    current_vars_file = joinpath(build_root, 'variables', variant_dir)
963    if isfile(current_vars_file):
964        sticky_vars.files.append(current_vars_file)
965        print "Using saved variables file %s" % current_vars_file
966    else:
967        # Build dir-specific variables file doesn't exist.
968
969        # Make sure the directory is there so we can create it later
970        opt_dir = dirname(current_vars_file)
971        if not isdir(opt_dir):
972            mkdir(opt_dir)
973
974        # Get default build variables from source tree.  Variables are
975        # normally determined by name of $VARIANT_DIR, but can be
976        # overridden by '--default=' arg on command line.
977        default = GetOption('default')
978        opts_dir = joinpath(main.root.abspath, 'build_opts')
979        if default:
980            default_vars_files = [joinpath(build_root, 'variables', default),
981                                  joinpath(opts_dir, default)]
982        else:
983            default_vars_files = [joinpath(opts_dir, variant_dir)]
984        existing_files = filter(isfile, default_vars_files)
985        if existing_files:
986            default_vars_file = existing_files[0]
987            sticky_vars.files.append(default_vars_file)
988            print "Variables file %s not found,\n  using defaults in %s" \
989                  % (current_vars_file, default_vars_file)
990        else:
991            print "Error: cannot find variables file %s or " \
992                  "default file(s) %s" \
993                  % (current_vars_file, ' or '.join(default_vars_files))
994            Exit(1)
995
996    # Apply current variable settings to env
997    sticky_vars.Update(env)
998
999    help_texts["local_vars"] += \
1000        "Build variables for %s:\n" % variant_dir \
1001                 + sticky_vars.GenerateHelpText(env)
1002
1003    # Process variable settings.
1004
1005    if not have_fenv and env['USE_FENV']:
1006        print "Warning: <fenv.h> not available; " \
1007              "forcing USE_FENV to False in", variant_dir + "."
1008        env['USE_FENV'] = False
1009
1010    if not env['USE_FENV']:
1011        print "Warning: No IEEE FP rounding mode control in", variant_dir + "."
1012        print "         FP results may deviate slightly from other platforms."
1013
1014    if env['EFENCE']:
1015        env.Append(LIBS=['efence'])
1016
1017    # Save sticky variable settings back to current variables file
1018    sticky_vars.Save(current_vars_file, env)
1019
1020    if env['USE_SSE2']:
1021        env.Append(CCFLAGS=['-msse2'])
1022
1023    # The src/SConscript file sets up the build rules in 'env' according
1024    # to the configured variables.  It returns a list of environments,
1025    # one for each variant build (debug, opt, etc.)
1026    envList = SConscript('src/SConscript', variant_dir = variant_path,
1027                         exports = 'env')
1028
1029    # Set up the regression tests for each build.
1030    for e in envList:
1031        SConscript('tests/SConscript',
1032                   variant_dir = joinpath(variant_path, 'tests', e.Label),
1033                   exports = { 'env' : e }, duplicate = False)
1034
1035# base help text
1036Help('''
1037Usage: scons [scons options] [build variables] [target(s)]
1038
1039Extra scons options:
1040%(options)s
1041
1042Global build variables:
1043%(global_vars)s
1044
1045%(local_vars)s
1046''' % help_texts)
1047