3 # Copyright (c) 2013 ARM Limited
6 # The license below extends only to copyright in the software and shall
7 # not be construed as granting a license to any other intellectual
8 # property including but not limited to intellectual property relating
9 # to a hardware implementation of the functionality of the software
10 # licensed hereunder. You may use the software subject to the license
11 # terms below provided that you ensure that this notice is replicated
12 # unmodified and in its entirety in all distributions of the software,
13 # modified or unmodified, in source code or in binary form.
15 # Copyright (c) 2011 Advanced Micro Devices, Inc.
16 # Copyright (c) 2009 The Hewlett-Packard Development Company
17 # Copyright (c) 2004-2005 The Regents of The University of Michigan
18 # All rights reserved.
20 # Redistribution and use in source and binary forms, with or without
21 # modification, are permitted provided that the following conditions are
22 # met: redistributions of source code must retain the above copyright
23 # notice, this list of conditions and the following disclaimer;
24 # redistributions in binary form must reproduce the above copyright
25 # notice, this list of conditions and the following disclaimer in the
26 # documentation and/or other materials provided with the distribution;
27 # neither the name of the copyright holders nor the names of its
28 # contributors may be used to endorse or promote products derived from
29 # this software without specific prior written permission.
31 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 # Authors: Steve Reinhardt
46 ###################################################
48 # SCons top-level build description (SConstruct) file.
50 # While in this directory ('gem5'), just type 'scons' to build the default
51 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
52 # to build some other configuration (e.g., 'build/ALPHA/gem5.opt' for
53 # the optimized full-system version).
55 # You can build gem5 in a different directory as long as there is a
56 # 'build/<CONFIG>' somewhere along the target path. The build system
57 # expects that all configs under the same build directory are being
58 # built for the same host system.
62 # The following two commands are equivalent. The '-u' option tells
63 # scons to search up the directory tree for this SConstruct file.
64 # % cd <path-to-src>/gem5 ; scons build/ALPHA/gem5.debug
65 # % cd <path-to-src>/gem5/build/ALPHA; scons -u gem5.debug
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
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
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
79 ###################################################
81 # Check for recent-enough Python and SCons versions.
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)
91 For more details, see:
92 http://gem5.org/Dependencies
96 # We ensure the python version early because because python-config
99 EnsurePythonVersion(2, 5)
100 except SystemExit, e
:
102 You can use a non-default installation of the Python interpreter by
103 rearranging your PATH so that scons finds the non-default 'python' and
104 'python-config' first.
106 For more details, see:
107 http://gem5.org/wiki/index.php/Using_a_non-default_Python_installation
111 # Global Python includes
117 from os
import mkdir
, environ
118 from os
.path
import abspath
, basename
, dirname
, expanduser
, normpath
119 from os
.path
import exists
, isdir
, isfile
120 from os
.path
import join
as joinpath
, split
as splitpath
126 extra_python_paths
= [
127 Dir('src/python').srcnode().abspath
, # gem5 includes
128 Dir('ext/ply').srcnode().abspath
, # ply is used by several files
131 sys
.path
[1:1] = extra_python_paths
133 from m5
.util
import compareVersions
, readCommand
134 from m5
.util
.terminal
import get_termcap
145 # There's a bug in scons in that (1) by default, the help texts from
146 # AddOption() are supposed to be displayed when you type 'scons -h'
147 # and (2) you can override the help displayed by 'scons -h' using the
148 # Help() function, but these two features are incompatible: once
149 # you've overridden the help text using Help(), there's no way to get
150 # at the help texts from AddOptions. See:
151 # http://scons.tigris.org/issues/show_bug.cgi?id=2356
152 # http://scons.tigris.org/issues/show_bug.cgi?id=2611
153 # This hack lets us extract the help text from AddOptions and
154 # re-inject it via Help(). Ideally someday this bug will be fixed and
155 # we can just use AddOption directly.
156 def AddLocalOption(*args
, **kwargs
):
159 help = " " + ", ".join(args
)
162 if length
>= col_width
:
163 help += "\n" + " " * col_width
165 help += " " * (col_width
- length
)
166 help += kwargs
["help"]
167 help_texts
["options"] += help + "\n"
169 AddOption(*args
, **kwargs
)
171 AddLocalOption('--colors', dest
='use_colors', action
='store_true',
172 help="Add color to abbreviated scons output")
173 AddLocalOption('--no-colors', dest
='use_colors', action
='store_false',
174 help="Don't add color to abbreviated scons output")
175 AddLocalOption('--default', dest
='default', type='string', action
='store',
176 help='Override which build_opts file to use for defaults')
177 AddLocalOption('--ignore-style', dest
='ignore_style', action
='store_true',
178 help='Disable style checking hooks')
179 AddLocalOption('--no-lto', dest
='no_lto', action
='store_true',
180 help='Disable Link-Time Optimization for fast')
181 AddLocalOption('--update-ref', dest
='update_ref', action
='store_true',
182 help='Update test reference outputs')
183 AddLocalOption('--verbose', dest
='verbose', action
='store_true',
184 help='Print full tool command lines')
186 termcap
= get_termcap(GetOption('use_colors'))
188 ########################################################################
190 # Set up the main build environment.
192 ########################################################################
194 # export TERM so that clang reports errors in color
195 use_vars
= set([ 'AS', 'AR', 'CC', 'CXX', 'HOME', 'LD_LIBRARY_PATH',
196 'LIBRARY_PATH', 'PATH', 'PKG_CONFIG_PATH', 'PROTOC',
197 'PYTHONPATH', 'RANLIB', 'SWIG', 'TERM' ])
200 "M5", # M5 configuration (e.g., path to kernels)
201 "DISTCC_", # distcc (distributed compiler wrapper) configuration
202 "CCACHE_", # ccache (caching compiler wrapper) configuration
203 "CCC_", # clang static analyzer configuration
207 for key
,val
in os
.environ
.iteritems():
208 if key
in use_vars
or \
209 any([key
.startswith(prefix
) for prefix
in use_prefixes
]):
212 main
= Environment(ENV
=use_env
)
213 main
.Decider('MD5-timestamp')
214 main
.root
= Dir(".") # The current directory (where this file lives).
215 main
.srcdir
= Dir("src") # The source directory
217 main_dict_keys
= main
.Dictionary().keys()
219 # Check that we have a C/C++ compiler
220 if not ('CC' in main_dict_keys
and 'CXX' in main_dict_keys
):
221 print "No C++ compiler installed (package g++ on Ubuntu and RedHat)"
224 # Check that swig is present
225 if not 'SWIG' in main_dict_keys
:
226 print "swig is not installed (package swig on Ubuntu and RedHat)"
229 # add useful python code PYTHONPATH so it can be used by subprocesses
231 main
.AppendENVPath('PYTHONPATH', extra_python_paths
)
233 ########################################################################
237 # If the gem5 directory is a mercurial repository, we should do some
240 ########################################################################
242 hgdir
= main
.root
.Dir(".hg")
244 mercurial_style_message
= """
245 You're missing the gem5 style hook, which automatically checks your code
246 against the gem5 style rules on hg commit and qrefresh commands. This
247 script will now install the hook in your .hg/hgrc file.
248 Press enter to continue, or ctrl-c to abort: """
250 mercurial_style_hook
= """
251 # The following lines were automatically added by gem5/SConstruct
252 # to provide the gem5 style-checking hooks
254 style = %s/util/style.py
257 pretxncommit.style = python:style.check_style
258 pre-qrefresh.style = python:style.check_style
259 # End of SConstruct additions
261 """ % (main
.root
.abspath
)
263 mercurial_lib_not_found
= """
264 Mercurial libraries cannot be found, ignoring style hook. If
265 you are a gem5 developer, please fix this and run the style
266 hook. It is important.
269 # Check for style hook and prompt for installation if it's not there.
270 # Skip this if --ignore-style was specified, there's no .hg dir to
271 # install a hook in, or there's no interactive terminal to prompt.
272 if not GetOption('ignore_style') and hgdir
.exists() and sys
.stdin
.isatty():
275 from mercurial
import ui
277 ui
.readconfig(hgdir
.File('hgrc').abspath
)
278 style_hook
= ui
.config('hooks', 'pretxncommit.style', None) and \
279 ui
.config('hooks', 'pre-qrefresh.style', None)
281 print mercurial_lib_not_found
284 print mercurial_style_message
,
285 # continue unless user does ctrl-c/ctrl-d etc.
289 print "Input exception, exiting scons.\n"
291 hgrc_path
= '%s/.hg/hgrc' % main
.root
.abspath
292 print "Adding style hook to", hgrc_path
, "\n"
294 hgrc
= open(hgrc_path
, 'a')
295 hgrc
.write(mercurial_style_hook
)
298 print "Error updating", hgrc_path
302 ###################################################
304 # Figure out which configurations to set up based on the path(s) of
307 ###################################################
309 # Find default configuration & binary.
310 Default(environ
.get('M5_DEFAULT_BINARY', 'build/ALPHA/gem5.debug'))
312 # helper function: find last occurrence of element in list
313 def rfind(l
, elt
, offs
= -1):
314 for i
in range(len(l
)+offs
, 0, -1):
317 raise ValueError, "element not found"
319 # Take a list of paths (or SCons Nodes) and return a list with all
320 # paths made absolute and ~-expanded. Paths will be interpreted
321 # relative to the launch directory unless a different root is provided
322 def makePathListAbsolute(path_list
, root
=GetLaunchDir()):
323 return [abspath(joinpath(root
, expanduser(str(p
))))
326 # Each target must have 'build' in the interior of the path; the
327 # directory below this will determine the build parameters. For
328 # example, for target 'foo/bar/build/ALPHA_SE/arch/alpha/blah.do' we
329 # recognize that ALPHA_SE specifies the configuration because it
330 # follow 'build' in the build path.
332 # The funky assignment to "[:]" is needed to replace the list contents
333 # in place rather than reassign the symbol to a new list, which
334 # doesn't work (obviously!).
335 BUILD_TARGETS
[:] = makePathListAbsolute(BUILD_TARGETS
)
337 # Generate a list of the unique build roots and configs that the
338 # collected targets reference.
341 for t
in BUILD_TARGETS
:
342 path_dirs
= t
.split('/')
344 build_top
= rfind(path_dirs
, 'build', -2)
346 print "Error: no non-leaf 'build' dir found on target path", t
348 this_build_root
= joinpath('/',*path_dirs
[:build_top
+1])
350 build_root
= this_build_root
352 if this_build_root
!= build_root
:
353 print "Error: build targets not under same build root\n"\
354 " %s\n %s" % (build_root
, this_build_root
)
356 variant_path
= joinpath('/',*path_dirs
[:build_top
+2])
357 if variant_path
not in variant_paths
:
358 variant_paths
.append(variant_path
)
360 # Make sure build_root exists (might not if this is the first build there)
361 if not isdir(build_root
):
363 main
['BUILDROOT'] = build_root
367 main
.SConsignFile(joinpath(build_root
, "sconsign"))
369 # Default duplicate option is to use hard links, but this messes up
370 # when you use emacs to edit a file in the target dir, as emacs moves
371 # file to file~ then copies to file, breaking the link. Symbolic
372 # (soft) links work better.
373 main
.SetOption('duplicate', 'soft-copy')
376 # Set up global sticky variables... these are common to an entire build
377 # tree (not specific to a particular build like ALPHA_SE)
380 global_vars_file
= joinpath(build_root
, 'variables.global')
382 global_vars
= Variables(global_vars_file
, args
=ARGUMENTS
)
384 global_vars
.AddVariables(
385 ('CC', 'C compiler', environ
.get('CC', main
['CC'])),
386 ('CXX', 'C++ compiler', environ
.get('CXX', main
['CXX'])),
387 ('SWIG', 'SWIG tool', environ
.get('SWIG', main
['SWIG'])),
388 ('PROTOC', 'protoc tool', environ
.get('PROTOC', 'protoc')),
389 ('BATCH', 'Use batch pool for build and tests', False),
390 ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
391 ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
392 ('EXTRAS', 'Add extra directories to the compilation', '')
395 # Update main environment with values from ARGUMENTS & global_vars_file
396 global_vars
.Update(main
)
397 help_texts
["global_vars"] += global_vars
.GenerateHelpText(main
)
399 # Save sticky variable settings back to current variables file
400 global_vars
.Save(global_vars_file
, main
)
402 # Parse EXTRAS variable to build list of all directories where we're
403 # look for sources etc. This list is exported as extras_dir_list.
404 base_dir
= main
.srcdir
.abspath
406 extras_dir_list
= makePathListAbsolute(main
['EXTRAS'].split(':'))
411 Export('extras_dir_list')
413 # the ext directory should be on the #includes path
414 main
.Append(CPPPATH
=[Dir('ext')])
416 def strip_build_path(path
, env
):
418 variant_base
= env
['BUILDROOT'] + os
.path
.sep
419 if path
.startswith(variant_base
):
420 path
= path
[len(variant_base
):]
421 elif path
.startswith('build/'):
425 # Generate a string of the form:
426 # common/path/prefix/src1, src2 -> tgt1, tgt2
427 # to print while building.
428 class Transform(object):
429 # all specific color settings should be here and nowhere else
430 tool_color
= termcap
.Normal
431 pfx_color
= termcap
.Yellow
432 srcs_color
= termcap
.Yellow
+ termcap
.Bold
433 arrow_color
= termcap
.Blue
+ termcap
.Bold
434 tgts_color
= termcap
.Yellow
+ termcap
.Bold
436 def __init__(self
, tool
, max_sources
=99):
437 self
.format
= self
.tool_color
+ (" [%8s] " % tool
) \
438 + self
.pfx_color
+ "%s" \
439 + self
.srcs_color
+ "%s" \
440 + self
.arrow_color
+ " -> " \
441 + self
.tgts_color
+ "%s" \
443 self
.max_sources
= max_sources
445 def __call__(self
, target
, source
, env
, for_signature
=None):
446 # truncate source list according to max_sources param
447 source
= source
[0:self
.max_sources
]
449 return strip_build_path(str(f
), env
)
451 srcs
= map(strip
, source
)
454 tgts
= map(strip
, target
)
455 # surprisingly, os.path.commonprefix is a dumb char-by-char string
456 # operation that has nothing to do with paths.
457 com_pfx
= os
.path
.commonprefix(srcs
+ tgts
)
458 com_pfx_len
= len(com_pfx
)
460 # do some cleanup and sanity checking on common prefix
461 if com_pfx
[-1] == ".":
462 # prefix matches all but file extension: ok
463 # back up one to change 'foo.cc -> o' to 'foo.cc -> .o'
464 com_pfx
= com_pfx
[0:-1]
465 elif com_pfx
[-1] == "/":
466 # common prefix is directory path: OK
469 src0_len
= len(srcs
[0])
470 tgt0_len
= len(tgts
[0])
471 if src0_len
== com_pfx_len
:
472 # source is a substring of target, OK
474 elif tgt0_len
== com_pfx_len
:
475 # target is a substring of source, need to back up to
476 # avoid empty string on RHS of arrow
477 sep_idx
= com_pfx
.rfind(".")
479 com_pfx
= com_pfx
[0:sep_idx
]
482 elif src0_len
> com_pfx_len
and srcs
[0][com_pfx_len
] == ".":
483 # still splitting at file extension: ok
486 # probably a fluke; ignore it
488 # recalculate length in case com_pfx was modified
489 com_pfx_len
= len(com_pfx
)
491 f
= map(lambda s
: s
[com_pfx_len
:], files
)
493 return self
.format
% (com_pfx
, fmt(srcs
), fmt(tgts
))
497 # enable the regression script to use the termcap
498 main
['TERMCAP'] = termcap
500 if GetOption('verbose'):
501 def MakeAction(action
, string
, *args
, **kwargs
):
502 return Action(action
, *args
, **kwargs
)
505 main
['CCCOMSTR'] = Transform("CC")
506 main
['CXXCOMSTR'] = Transform("CXX")
507 main
['ASCOMSTR'] = Transform("AS")
508 main
['SWIGCOMSTR'] = Transform("SWIG")
509 main
['ARCOMSTR'] = Transform("AR", 0)
510 main
['LINKCOMSTR'] = Transform("LINK", 0)
511 main
['RANLIBCOMSTR'] = Transform("RANLIB", 0)
512 main
['M4COMSTR'] = Transform("M4")
513 main
['SHCCCOMSTR'] = Transform("SHCC")
514 main
['SHCXXCOMSTR'] = Transform("SHCXX")
517 # Initialize the Link-Time Optimization (LTO) flags
518 main
['LTO_CCFLAGS'] = []
519 main
['LTO_LDFLAGS'] = []
521 # According to the readme, tcmalloc works best if the compiler doesn't
522 # assume that we're using the builtin malloc and friends. These flags
523 # are compiler-specific, so we need to set them after we detect which
524 # compiler we're using.
525 main
['TCMALLOC_CCFLAGS'] = []
527 CXX_version
= readCommand([main
['CXX'],'--version'], exception
=False)
528 CXX_V
= readCommand([main
['CXX'],'-V'], exception
=False)
530 main
['GCC'] = CXX_version
and CXX_version
.find('g++') >= 0
531 main
['CLANG'] = CXX_version
and CXX_version
.find('clang') >= 0
532 if main
['GCC'] + main
['CLANG'] > 1:
533 print 'Error: How can we have two at the same time?'
536 # Set up default C++ compiler flags
537 if main
['GCC'] or main
['CLANG']:
538 # As gcc and clang share many flags, do the common parts here
539 main
.Append(CCFLAGS
=['-pipe'])
540 main
.Append(CCFLAGS
=['-fno-strict-aliasing'])
541 # Enable -Wall and then disable the few warnings that we
542 # consistently violate
543 main
.Append(CCFLAGS
=['-Wall', '-Wno-sign-compare', '-Wundef'])
544 # We always compile using C++11, but only gcc >= 4.7 and clang 3.1
545 # actually use that name, so we stick with c++0x
546 main
.Append(CXXFLAGS
=['-std=c++0x'])
547 # Add selected sanity checks from -Wextra
548 main
.Append(CXXFLAGS
=['-Wmissing-field-initializers',
549 '-Woverloaded-virtual'])
551 print termcap
.Yellow
+ termcap
.Bold
+ 'Error' + termcap
.Normal
,
552 print "Don't know what compiler options to use for your compiler."
553 print termcap
.Yellow
+ ' compiler:' + termcap
.Normal
, main
['CXX']
554 print termcap
.Yellow
+ ' version:' + termcap
.Normal
,
556 print termcap
.Yellow
+ termcap
.Bold
+ "COMMAND NOT FOUND!" +\
559 print CXX_version
.replace('\n', '<nl>')
560 print " If you're trying to use a compiler other than GCC"
561 print " or clang, there appears to be something wrong with your"
562 print " environment."
564 print " If you are trying to use a compiler other than those listed"
565 print " above you will need to ease fix SConstruct and "
566 print " src/SConscript to support that compiler."
570 # Check for a supported version of gcc, >= 4.4 is needed for c++0x
571 # support. See http://gcc.gnu.org/projects/cxx0x.html for details
572 gcc_version
= readCommand([main
['CXX'], '-dumpversion'], exception
=False)
573 if compareVersions(gcc_version
, "4.4") < 0:
574 print 'Error: gcc version 4.4 or newer required.'
575 print ' Installed version:', gcc_version
578 main
['GCC_VERSION'] = gcc_version
580 # Check for versions with bugs
581 if not compareVersions(gcc_version
, '4.4.1') or \
582 not compareVersions(gcc_version
, '4.4.2'):
583 print 'Info: Tree vectorizer in GCC 4.4.1 & 4.4.2 is buggy, disabling.'
584 main
.Append(CCFLAGS
=['-fno-tree-vectorize'])
586 # LTO support is only really working properly from 4.6 and beyond
587 if compareVersions(gcc_version
, '4.6') >= 0:
588 # Add the appropriate Link-Time Optimization (LTO) flags
589 # unless LTO is explicitly turned off. Note that these flags
590 # are only used by the fast target.
591 if not GetOption('no_lto'):
592 # Pass the LTO flag when compiling to produce GIMPLE
593 # output, we merely create the flags here and only append
595 main
['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
597 # Use the same amount of jobs for LTO as we are running
598 # scons with, we hardcode the use of the linker plugin
599 # which requires either gold or GNU ld >= 2.21
600 main
['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs'),
601 '-fuse-linker-plugin']
603 main
.Append(TCMALLOC_CCFLAGS
=['-fno-builtin-malloc', '-fno-builtin-calloc',
604 '-fno-builtin-realloc', '-fno-builtin-free'])
607 # Check for a supported version of clang, >= 2.9 is needed to
608 # support similar features as gcc 4.4. See
609 # http://clang.llvm.org/cxx_status.html for details
610 clang_version_re
= re
.compile(".* version (\d+\.\d+)")
611 clang_version_match
= clang_version_re
.search(CXX_version
)
612 if (clang_version_match
):
613 clang_version
= clang_version_match
.groups()[0]
614 if compareVersions(clang_version
, "2.9") < 0:
615 print 'Error: clang version 2.9 or newer required.'
616 print ' Installed version:', clang_version
619 print 'Error: Unable to determine clang version.'
622 # clang has a few additional warnings that we disable,
623 # tautological comparisons are allowed due to unsigned integers
624 # being compared to constants that happen to be 0, and extraneous
625 # parantheses are allowed due to Ruby's printing of the AST,
626 # finally self assignments are allowed as the generated CPU code
628 main
.Append(CCFLAGS
=['-Wno-tautological-compare',
632 main
.Append(TCMALLOC_CCFLAGS
=['-fno-builtin'])
634 # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
635 # opposed to libstdc++, as the later is dated.
636 if sys
.platform
== "darwin":
637 main
.Append(CXXFLAGS
=['-stdlib=libc++'])
638 main
.Append(LIBS
=['c++'])
641 print termcap
.Yellow
+ termcap
.Bold
+ 'Error' + termcap
.Normal
,
642 print "Don't know what compiler options to use for your compiler."
643 print termcap
.Yellow
+ ' compiler:' + termcap
.Normal
, main
['CXX']
644 print termcap
.Yellow
+ ' version:' + termcap
.Normal
,
646 print termcap
.Yellow
+ termcap
.Bold
+ "COMMAND NOT FOUND!" +\
649 print CXX_version
.replace('\n', '<nl>')
650 print " If you're trying to use a compiler other than GCC"
651 print " or clang, there appears to be something wrong with your"
652 print " environment."
654 print " If you are trying to use a compiler other than those listed"
655 print " above you will need to ease fix SConstruct and "
656 print " src/SConscript to support that compiler."
659 # Set up common yacc/bison flags (needed for Ruby)
660 main
['YACCFLAGS'] = '-d'
661 main
['YACCHXXFILESUFFIX'] = '.hh'
663 # Do this after we save setting back, or else we'll tack on an
664 # extra 'qdo' every time we run scons.
666 main
['CC'] = main
['BATCH_CMD'] + ' ' + main
['CC']
667 main
['CXX'] = main
['BATCH_CMD'] + ' ' + main
['CXX']
668 main
['AS'] = main
['BATCH_CMD'] + ' ' + main
['AS']
669 main
['AR'] = main
['BATCH_CMD'] + ' ' + main
['AR']
670 main
['RANLIB'] = main
['BATCH_CMD'] + ' ' + main
['RANLIB']
672 if sys
.platform
== 'cygwin':
673 # cygwin has some header file issues...
674 main
.Append(CCFLAGS
=["-Wno-uninitialized"])
676 # Check for the protobuf compiler
677 protoc_version
= readCommand([main
['PROTOC'], '--version'],
678 exception
='').split()
680 # First two words should be "libprotoc x.y.z"
681 if len(protoc_version
) < 2 or protoc_version
[0] != 'libprotoc':
682 print termcap
.Yellow
+ termcap
.Bold
+ \
683 'Warning: Protocol buffer compiler (protoc) not found.\n' + \
684 ' Please install protobuf-compiler for tracing support.' + \
686 main
['PROTOC'] = False
688 # Based on the availability of the compress stream wrappers,
690 min_protoc_version
= '2.1.0'
691 if compareVersions(protoc_version
[1], min_protoc_version
) < 0:
692 print termcap
.Yellow
+ termcap
.Bold
+ \
693 'Warning: protoc version', min_protoc_version
, \
694 'or newer required.\n' + \
695 ' Installed version:', protoc_version
[1], \
697 main
['PROTOC'] = False
699 # Attempt to determine the appropriate include path and
700 # library path using pkg-config, that means we also need to
701 # check for pkg-config. Note that it is possible to use
702 # protobuf without the involvement of pkg-config. Later on we
703 # check go a library config check and at that point the test
704 # will fail if libprotobuf cannot be found.
705 if readCommand(['pkg-config', '--version'], exception
=''):
707 # Attempt to establish what linking flags to add for protobuf
709 main
.ParseConfig('pkg-config --cflags --libs-only-L protobuf')
711 print termcap
.Yellow
+ termcap
.Bold
+ \
712 'Warning: pkg-config could not get protobuf flags.' + \
716 if not main
.has_key('SWIG'):
717 print 'Error: SWIG utility not found.'
718 print ' Please install (see http://www.swig.org) and retry.'
721 # Check for appropriate SWIG version
722 swig_version
= readCommand([main
['SWIG'], '-version'], exception
='').split()
723 # First 3 words should be "SWIG Version x.y.z"
724 if len(swig_version
) < 3 or \
725 swig_version
[0] != 'SWIG' or swig_version
[1] != 'Version':
726 print 'Error determining SWIG version.'
729 min_swig_version
= '1.3.34'
730 if compareVersions(swig_version
[2], min_swig_version
) < 0:
731 print 'Error: SWIG version', min_swig_version
, 'or newer required.'
732 print ' Installed version:', swig_version
[2]
735 # Older versions of swig do not play well with more recent versions of
736 # gcc due to assumptions on implicit includes (cstddef) and use of
738 if main
['GCC'] and compareVersions(gcc_version
, '4.6') > 0 and \
739 compareVersions(swig_version
[2], '2') < 0:
740 print '\n' + termcap
.Yellow
+ termcap
.Bold
+ \
741 'Warning: SWIG 1.x cause issues with gcc 4.6 and later.\n' + \
743 'Use SWIG 2.x to avoid assumptions on implicit includes\n' + \
744 'and use of namespaces\n'
746 # Set up SWIG flags & scanner
747 swig_flags
=Split('-c++ -python -modern -templatereduce $_CPPINCFLAGS')
748 main
.Append(SWIGFLAGS
=swig_flags
)
750 # filter out all existing swig scanners, they mess up the dependency
751 # stuff for some reason
753 for scanner
in main
['SCANNERS']:
754 skeys
= scanner
.skeys
758 if isinstance(skeys
, (list, tuple)) and '.i' in skeys
:
761 scanners
.append(scanner
)
763 # add the new swig scanner that we like better
764 from SCons
.Scanner
import ClassicCPP
as CPPScanner
765 swig_inc_re
= '^[ \t]*[%,#][ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")'
766 scanners
.append(CPPScanner("SwigScan", [ ".i" ], "CPPPATH", swig_inc_re
))
768 # replace the scanners list that has what we want
769 main
['SCANNERS'] = scanners
771 # Add a custom Check function to the Configure context so that we can
772 # figure out if the compiler adds leading underscores to global
773 # variables. This is needed for the autogenerated asm files that we
774 # use for embedding the python code.
775 def CheckLeading(context
):
776 context
.Message("Checking for leading underscore in global variables...")
777 # 1) Define a global variable called x from asm so the C compiler
778 # won't change the symbol at all.
779 # 2) Declare that variable.
780 # 3) Use the variable
782 # If the compiler prepends an underscore, this will successfully
783 # link because the external symbol 'x' will be called '_x' which
784 # was defined by the asm statement. If the compiler does not
785 # prepend an underscore, this will not successfully link because
786 # '_x' will have been defined by assembly, while the C portion of
787 # the code will be trying to use 'x'
788 ret
= context
.TryLink('''
789 asm(".globl _x; _x: .byte 0");
791 int main() { return x; }
793 context
.env
.Append(LEADING_UNDERSCORE
=ret
)
797 # Add a custom Check function to test for structure members.
798 def CheckMember(context
, include
, decl
, member
, include_quotes
="<>"):
799 context
.Message("Checking for member %s in %s..." %
805 (void)test.%(member)s;
808 """ % { "header" : include_quotes
[0] + include
+ include_quotes
[1],
813 ret
= context
.TryCompile(text
, extension
=".cc")
817 # Platform-specific configuration. Note again that we assume that all
818 # builds under a given build root run on the same host platform.
819 conf
= Configure(main
,
820 conf_dir
= joinpath(build_root
, '.scons_config'),
821 log_file
= joinpath(build_root
, 'scons_config.log'),
823 'CheckLeading' : CheckLeading
,
824 'CheckMember' : CheckMember
,
827 # Check for leading underscores. Don't really need to worry either
828 # way so don't need to check the return code.
831 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
834 uname
= platform
.uname()
835 if uname
[0] == 'Darwin' and compareVersions(uname
[2], '9.0.0') >= 0:
836 if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
837 main
.Append(CCFLAGS
=['-arch', 'x86_64'])
838 main
.Append(CFLAGS
=['-arch', 'x86_64'])
839 main
.Append(LINKFLAGS
=['-arch', 'x86_64'])
840 main
.Append(ASFLAGS
=['-arch', 'x86_64'])
844 # Recent versions of scons substitute a "Null" object for Configure()
845 # when configuration isn't necessary, e.g., if the "--help" option is
846 # present. Unfortuantely this Null object always returns false,
847 # breaking all our configuration checks. We replace it with our own
848 # more optimistic null object that returns True instead.
850 def NullCheck(*args
, **kwargs
):
854 def __init__(self
, env
):
858 def __getattr__(self
, mname
):
861 conf
= NullConf(main
)
863 # Cache build files in the supplied directory.
864 if main
['M5_BUILD_CACHE']:
865 print 'Using build cache located at', main
['M5_BUILD_CACHE']
866 CacheDir(main
['M5_BUILD_CACHE'])
868 # Find Python include and library directories for embedding the
869 # interpreter. We rely on python-config to resolve the appropriate
870 # includes and linker flags. ParseConfig does not seem to understand
871 # the more exotic linker flags such as -Xlinker and -export-dynamic so
872 # we add them explicitly below. If you want to link in an alternate
873 # version of python, see above for instructions on how to invoke
874 # scons with the appropriate PATH set.
875 py_includes
= readCommand(['python-config', '--includes'],
876 exception
='').split()
877 # Strip the -I from the include folders before adding them to the
879 main
.Append(CPPPATH
=map(lambda inc
: inc
[2:], py_includes
))
881 # Read the linker flags and split them into libraries and other link
882 # flags. The libraries are added later through the call the CheckLib.
883 py_ld_flags
= readCommand(['python-config', '--ldflags'], exception
='').split()
885 for lib
in py_ld_flags
:
886 if not lib
.startswith('-l'):
887 main
.Append(LINKFLAGS
=[lib
])
890 if lib
not in py_libs
:
893 # verify that this stuff works
894 if not conf
.CheckHeader('Python.h', '<>'):
895 print "Error: can't find Python.h header in", py_includes
896 print "Install Python headers (package python-dev on Ubuntu and RedHat)"
900 if not conf
.CheckLib(lib
):
901 print "Error: can't find library %s required by python" % lib
904 # On Solaris you need to use libsocket for socket ops
905 if not conf
.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
906 if not conf
.CheckLibWithHeader('socket', 'sys/socket.h', 'C++', 'accept(0,0,0);'):
907 print "Can't find library with socket calls (e.g. accept())"
910 # Check for zlib. If the check passes, libz will be automatically
911 # added to the LIBS environment variable.
912 if not conf
.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
913 print 'Error: did not find needed zlib compression library '\
914 'and/or zlib.h header file.'
915 print ' Please install zlib and try again.'
918 # If we have the protobuf compiler, also make sure we have the
919 # development libraries. If the check passes, libprotobuf will be
920 # automatically added to the LIBS environment variable. After
921 # this, we can use the HAVE_PROTOBUF flag to determine if we have
922 # got both protoc and libprotobuf available.
923 main
['HAVE_PROTOBUF'] = main
['PROTOC'] and \
924 conf
.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
925 'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
927 # If we have the compiler but not the library, print another warning.
928 if main
['PROTOC'] and not main
['HAVE_PROTOBUF']:
929 print termcap
.Yellow
+ termcap
.Bold
+ \
930 'Warning: did not find protocol buffer library and/or headers.\n' + \
931 ' Please install libprotobuf-dev for tracing support.' + \
936 conf
.CheckLibWithHeader(None, 'time.h', 'C',
937 'clock_nanosleep(0,0,NULL,NULL);') or \
938 conf
.CheckLibWithHeader('rt', 'time.h', 'C',
939 'clock_nanosleep(0,0,NULL,NULL);')
941 have_posix_timers
= \
942 conf
.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
943 'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
945 if conf
.CheckLib('tcmalloc'):
946 main
.Append(CCFLAGS
=main
['TCMALLOC_CCFLAGS'])
947 elif conf
.CheckLib('tcmalloc_minimal'):
948 main
.Append(CCFLAGS
=main
['TCMALLOC_CCFLAGS'])
950 print termcap
.Yellow
+ termcap
.Bold
+ \
951 "You can get a 12% performance improvement by installing tcmalloc "\
952 "(libgoogle-perftools-dev package on Ubuntu or RedHat)." + \
955 if not have_posix_clock
:
956 print "Can't find library for POSIX clocks."
958 # Check for <fenv.h> (C99 FP environment control)
959 have_fenv
= conf
.CheckHeader('fenv.h', '<>')
961 print "Warning: Header file <fenv.h> not found."
962 print " This host has no IEEE FP rounding mode control."
964 # Check if we should enable KVM-based hardware virtualization. The API
965 # we rely on exists since version 2.6.36 of the kernel, but somehow
966 # the KVM_API_VERSION does not reflect the change. We test for one of
967 # the types as a fall back.
968 have_kvm
= conf
.CheckHeader('linux/kvm.h', '<>') and \
969 conf
.CheckTypeSize('struct kvm_xsave', '#include <linux/kvm.h>') != 0
971 print "Info: Compatible header file <linux/kvm.h> not found, " \
972 "disabling KVM support."
974 # Check if the requested target ISA is compatible with the host
975 def is_isa_kvm_compatible(isa
):
977 "arm" : ( "armv7l" ),
978 "x86" : ( "x86_64" ),
982 host_isa
= platform
.machine()
984 print "Warning: Failed to determine host ISA."
987 return host_isa
in isa_comp_table
.get(isa
, [])
990 # Check if the exclude_host attribute is available. We want this to
991 # get accurate instruction counts in KVM.
992 main
['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf
.CheckMember(
993 'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
996 ######################################################################
998 # Finish the configuration
1000 main
= conf
.Finish()
1002 ######################################################################
1004 # Collect all non-global variables
1007 # Define the universe of supported ISAs
1009 Export('all_isa_list')
1011 class CpuModel(object):
1012 '''The CpuModel class encapsulates everything the ISA parser needs to
1013 know about a particular CPU model.'''
1015 # Dict of available CPU model objects. Accessible as CpuModel.dict.
1020 # Constructor. Automatically adds models to CpuModel.dict.
1021 def __init__(self
, name
, filename
, includes
, strings
, default
=False):
1022 self
.name
= name
# name of model
1023 self
.filename
= filename
# filename for output exec code
1024 self
.includes
= includes
# include files needed in exec file
1025 # The 'strings' dict holds all the per-CPU symbols we can
1026 # substitute into templates etc.
1027 self
.strings
= strings
1029 # This cpu is enabled by default
1030 self
.default
= default
1033 if name
in CpuModel
.dict:
1034 raise AttributeError, "CpuModel '%s' already registered" % name
1035 CpuModel
.dict[name
] = self
1036 CpuModel
.list.append(name
)
1040 # Sticky variables get saved in the variables file so they persist from
1041 # one invocation to the next (unless overridden, in which case the new
1042 # value becomes sticky).
1043 sticky_vars
= Variables(args
=ARGUMENTS
)
1044 Export('sticky_vars')
1046 # Sticky variables that should be exported
1048 Export('export_vars')
1052 Export('all_protocols')
1054 Export('protocol_dirs')
1056 Export('slicc_includes')
1058 # Walk the tree and execute all SConsopts scripts that wil add to the
1060 if not GetOption('verbose'):
1061 print "Reading SConsopts"
1062 for bdir
in [ base_dir
] + extras_dir_list
:
1064 print "Error: directory '%s' does not exist" % bdir
1066 for root
, dirs
, files
in os
.walk(bdir
):
1067 if 'SConsopts' in files
:
1068 if GetOption('verbose'):
1069 print "Reading", joinpath(root
, 'SConsopts')
1070 SConscript(joinpath(root
, 'SConsopts'))
1074 sticky_vars
.AddVariables(
1075 EnumVariable('TARGET_ISA', 'Target ISA', 'alpha', all_isa_list
),
1076 ListVariable('CPU_MODELS', 'CPU models',
1077 sorted(n
for n
,m
in CpuModel
.dict.iteritems() if m
.default
),
1078 sorted(CpuModel
.list)),
1079 BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
1081 BoolVariable('SS_COMPATIBLE_FP',
1082 'Make floating-point results compatible with SimpleScalar',
1084 BoolVariable('USE_SSE2',
1085 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1087 BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock
),
1088 BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv
),
1089 BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability', False),
1090 BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models', have_kvm
),
1091 EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1095 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1096 export_vars
+= ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
1097 'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF',
1098 'HAVE_PERF_ATTR_EXCLUDE_HOST']
1100 ###################################################
1102 # Define a SCons builder for configuration flag headers.
1104 ###################################################
1106 # This function generates a config header file that #defines the
1107 # variable symbol to the current variable setting (0 or 1). The source
1108 # operands are the name of the variable and a Value node containing the
1109 # value of the variable.
1110 def build_config_file(target
, source
, env
):
1111 (variable
, value
) = [s
.get_contents() for s
in source
]
1112 f
= file(str(target
[0]), 'w')
1113 print >> f
, '#define', variable
, value
1117 # Combine the two functions into a scons Action object.
1118 config_action
= MakeAction(build_config_file
, Transform("CONFIG H", 2))
1120 # The emitter munges the source & target node lists to reflect what
1121 # we're really doing.
1122 def config_emitter(target
, source
, env
):
1123 # extract variable name from Builder arg
1124 variable
= str(target
[0])
1125 # True target is config header file
1126 target
= joinpath('config', variable
.lower() + '.hh')
1128 if isinstance(val
, bool):
1129 # Force value to 0/1
1131 elif isinstance(val
, str):
1132 val
= '"' + val
+ '"'
1134 # Sources are variable name & value (packaged in SCons Value nodes)
1135 return ([target
], [Value(variable
), Value(val
)])
1137 config_builder
= Builder(emitter
= config_emitter
, action
= config_action
)
1139 main
.Append(BUILDERS
= { 'ConfigFile' : config_builder
})
1141 # libelf build is shared across all configs in the build root.
1142 main
.SConscript('ext/libelf/SConscript',
1143 variant_dir
= joinpath(build_root
, 'libelf'))
1145 # gzstream build is shared across all configs in the build root.
1146 main
.SConscript('ext/gzstream/SConscript',
1147 variant_dir
= joinpath(build_root
, 'gzstream'))
1149 # libfdt build is shared across all configs in the build root.
1150 main
.SConscript('ext/libfdt/SConscript',
1151 variant_dir
= joinpath(build_root
, 'libfdt'))
1153 # fputils build is shared across all configs in the build root.
1154 main
.SConscript('ext/fputils/SConscript',
1155 variant_dir
= joinpath(build_root
, 'fputils'))
1157 # DRAMSim2 build is shared across all configs in the build root.
1158 main
.SConscript('ext/dramsim2/SConscript',
1159 variant_dir
= joinpath(build_root
, 'dramsim2'))
1161 ###################################################
1163 # This function is used to set up a directory with switching headers
1165 ###################################################
1167 main
['ALL_ISA_LIST'] = all_isa_list
1168 def make_switching_dir(dname
, switch_headers
, env
):
1169 # Generate the header. target[0] is the full path of the output
1170 # header to generate. 'source' is a dummy variable, since we get the
1171 # list of ISAs from env['ALL_ISA_LIST'].
1172 def gen_switch_hdr(target
, source
, env
):
1173 fname
= str(target
[0])
1174 f
= open(fname
, 'w')
1175 isa
= env
['TARGET_ISA'].lower()
1176 print >>f
, '#include "%s/%s/%s"' % (dname
, isa
, basename(fname
))
1179 # Build SCons Action object. 'varlist' specifies env vars that this
1180 # action depends on; when env['ALL_ISA_LIST'] changes these actions
1181 # should get re-executed.
1182 switch_hdr_action
= MakeAction(gen_switch_hdr
,
1183 Transform("GENERATE"), varlist
=['ALL_ISA_LIST'])
1185 # Instantiate actions for each header
1186 for hdr
in switch_headers
:
1187 env
.Command(hdr
, [], switch_hdr_action
)
1188 Export('make_switching_dir')
1190 ###################################################
1192 # Define build environments for selected configurations.
1194 ###################################################
1196 for variant_path
in variant_paths
:
1197 print "Building in", variant_path
1199 # Make a copy of the build-root environment to use for this config.
1201 env
['BUILDDIR'] = variant_path
1203 # variant_dir is the tail component of build path, and is used to
1204 # determine the build parameters (e.g., 'ALPHA_SE')
1205 (build_root
, variant_dir
) = splitpath(variant_path
)
1207 # Set env variables according to the build directory config.
1208 sticky_vars
.files
= []
1209 # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1210 # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1211 # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1212 current_vars_file
= joinpath(build_root
, 'variables', variant_dir
)
1213 if isfile(current_vars_file
):
1214 sticky_vars
.files
.append(current_vars_file
)
1215 print "Using saved variables file %s" % current_vars_file
1217 # Build dir-specific variables file doesn't exist.
1219 # Make sure the directory is there so we can create it later
1220 opt_dir
= dirname(current_vars_file
)
1221 if not isdir(opt_dir
):
1224 # Get default build variables from source tree. Variables are
1225 # normally determined by name of $VARIANT_DIR, but can be
1226 # overridden by '--default=' arg on command line.
1227 default
= GetOption('default')
1228 opts_dir
= joinpath(main
.root
.abspath
, 'build_opts')
1230 default_vars_files
= [joinpath(build_root
, 'variables', default
),
1231 joinpath(opts_dir
, default
)]
1233 default_vars_files
= [joinpath(opts_dir
, variant_dir
)]
1234 existing_files
= filter(isfile
, default_vars_files
)
1236 default_vars_file
= existing_files
[0]
1237 sticky_vars
.files
.append(default_vars_file
)
1238 print "Variables file %s not found,\n using defaults in %s" \
1239 % (current_vars_file
, default_vars_file
)
1241 print "Error: cannot find variables file %s or " \
1242 "default file(s) %s" \
1243 % (current_vars_file
, ' or '.join(default_vars_files
))
1246 # Apply current variable settings to env
1247 sticky_vars
.Update(env
)
1249 help_texts
["local_vars"] += \
1250 "Build variables for %s:\n" % variant_dir \
1251 + sticky_vars
.GenerateHelpText(env
)
1253 # Process variable settings.
1255 if not have_fenv
and env
['USE_FENV']:
1256 print "Warning: <fenv.h> not available; " \
1257 "forcing USE_FENV to False in", variant_dir
+ "."
1258 env
['USE_FENV'] = False
1260 if not env
['USE_FENV']:
1261 print "Warning: No IEEE FP rounding mode control in", variant_dir
+ "."
1262 print " FP results may deviate slightly from other platforms."
1265 env
.Append(LIBS
=['efence'])
1269 print "Warning: Can not enable KVM, host seems to lack KVM support"
1270 env
['USE_KVM'] = False
1271 elif not have_posix_timers
:
1272 print "Warning: Can not enable KVM, host seems to lack support " \
1274 env
['USE_KVM'] = False
1275 elif not is_isa_kvm_compatible(env
['TARGET_ISA']):
1276 print "Info: KVM support disabled due to unsupported host and " \
1277 "target ISA combination"
1278 env
['USE_KVM'] = False
1280 # Warn about missing optional functionality
1282 if not main
['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1283 print "Warning: perf_event headers lack support for the " \
1284 "exclude_host attribute. KVM instruction counts will " \
1287 # Save sticky variable settings back to current variables file
1288 sticky_vars
.Save(current_vars_file
, env
)
1291 env
.Append(CCFLAGS
=['-msse2'])
1293 # The src/SConscript file sets up the build rules in 'env' according
1294 # to the configured variables. It returns a list of environments,
1295 # one for each variant build (debug, opt, etc.)
1296 envList
= SConscript('src/SConscript', variant_dir
= variant_path
,
1299 # Set up the regression tests for each build.
1301 SConscript('tests/SConscript',
1302 variant_dir
= joinpath(variant_path
, 'tests', e
.Label
),
1303 exports
= { 'env' : e
}, duplicate
= False)
1307 Usage: scons [scons options] [build variables] [target(s)]
1309 Extra scons options:
1312 Global build variables: