3 # Copyright (c) 2013, 2015-2020 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 ###################################################
45 # SCons top-level build description (SConstruct) file.
47 # While in this directory ('gem5'), just type 'scons' to build the default
48 # configuration (see below), or type 'scons build/<CONFIG>/<binary>'
49 # to build some other configuration (e.g., 'build/X86/gem5.opt' for
50 # the optimized full-system version).
52 # You can build gem5 in a different directory as long as there is a
53 # 'build/<CONFIG>' somewhere along the target path. The build system
54 # expects that all configs under the same build directory are being
55 # built for the same host system.
59 # The following two commands are equivalent. The '-u' option tells
60 # scons to search up the directory tree for this SConstruct file.
61 # % cd <path-to-src>/gem5 ; scons build/X86/gem5.debug
62 # % cd <path-to-src>/gem5/build/X86; scons -u gem5.debug
64 # The following two commands are equivalent and demonstrate building
65 # in a directory outside of the source tree. The '-C' option tells
66 # scons to chdir to the specified directory to find this SConstruct
68 # % cd <path-to-src>/gem5 ; scons /local/foo/build/X86/gem5.debug
69 # % cd /local/foo/build/X86; scons -C <path-to-src>/gem5 gem5.debug
71 # You can use 'scons -H' to print scons options. If you're in this
72 # 'gem5' directory (or use -u or -C to tell scons where to find this
73 # file), you can use 'scons -h' to print all the gem5-specific build
76 ###################################################
78 from __future__
import print_function
80 # Global Python includes
89 from os
import mkdir
, environ
90 from os
.path
import abspath
, basename
, dirname
, expanduser
, normpath
91 from os
.path
import exists
, isdir
, isfile
92 from os
.path
import join
as joinpath
, split
as splitpath
100 from m5
.util
import compareVersions
, readCommand
, readCommandWithReturn
111 # There's a bug in scons in that (1) by default, the help texts from
112 # AddOption() are supposed to be displayed when you type 'scons -h'
113 # and (2) you can override the help displayed by 'scons -h' using the
114 # Help() function, but these two features are incompatible: once
115 # you've overridden the help text using Help(), there's no way to get
116 # at the help texts from AddOptions. See:
117 # https://github.com/SCons/scons/issues/2356
118 # https://github.com/SCons/scons/issues/2611
119 # This hack lets us extract the help text from AddOptions and
120 # re-inject it via Help(). Ideally someday this bug will be fixed and
121 # we can just use AddOption directly.
122 def AddLocalOption(*args
, **kwargs
):
125 help = " " + ", ".join(args
)
128 if length
>= col_width
:
129 help += "\n" + " " * col_width
131 help += " " * (col_width
- length
)
132 help += kwargs
["help"]
133 help_texts
["options"] += help + "\n"
135 AddOption(*args
, **kwargs
)
137 AddLocalOption('--colors', dest
='use_colors', action
='store_true',
138 help="Add color to abbreviated scons output")
139 AddLocalOption('--no-colors', dest
='use_colors', action
='store_false',
140 help="Don't add color to abbreviated scons output")
141 AddLocalOption('--with-cxx-config', action
='store_true',
142 help="Build with support for C++-based configuration")
143 AddLocalOption('--default',
144 help='Override which build_opts file to use for defaults')
145 AddLocalOption('--ignore-style', action
='store_true',
146 help='Disable style checking hooks')
147 AddLocalOption('--gold-linker', action
='store_true',
148 help='Use the gold linker')
149 AddLocalOption('--no-lto', action
='store_true',
150 help='Disable Link-Time Optimization for fast')
151 AddLocalOption('--force-lto', action
='store_true',
152 help='Use Link-Time Optimization instead of partial linking' +
153 ' when the compiler doesn\'t support using them together.')
154 AddLocalOption('--verbose', action
='store_true',
155 help='Print full tool command lines')
156 AddLocalOption('--without-python', action
='store_true',
157 help='Build without Python configuration support')
158 AddLocalOption('--without-tcmalloc', action
='store_true',
159 help='Disable linking against tcmalloc')
160 AddLocalOption('--with-ubsan', action
='store_true',
161 help='Build with Undefined Behavior Sanitizer if available')
162 AddLocalOption('--with-asan', action
='store_true',
163 help='Build with Address Sanitizer if available')
164 AddLocalOption('--with-systemc-tests', action
='store_true',
165 help='Build systemc tests')
167 from gem5_scons
import Transform
, error
, warning
, summarize_warnings
169 if GetOption('no_lto') and GetOption('force_lto'):
170 error('--no-lto and --force-lto are mutually exclusive')
172 ########################################################################
174 # Set up the main build environment.
176 ########################################################################
180 from gem5_scons
.util
import get_termcap
181 termcap
= get_termcap()
183 main_dict_keys
= main
.Dictionary().keys()
185 # Check that we have a C/C++ compiler
186 if not ('CC' in main_dict_keys
and 'CXX' in main_dict_keys
):
187 error("No C++ compiler installed (package g++ on Ubuntu and RedHat)")
189 ###################################################
191 # Figure out which configurations to set up based on the path(s) of
194 ###################################################
196 # Find default configuration & binary.
197 Default(environ
.get('M5_DEFAULT_BINARY', 'build/ARM/gem5.debug'))
199 # helper function: find last occurrence of element in list
200 def rfind(l
, elt
, offs
= -1):
201 for i
in range(len(l
)+offs
, 0, -1):
204 raise ValueError("element not found")
206 # Take a list of paths (or SCons Nodes) and return a list with all
207 # paths made absolute and ~-expanded. Paths will be interpreted
208 # relative to the launch directory unless a different root is provided
209 def makePathListAbsolute(path_list
, root
=GetLaunchDir()):
210 return [abspath(joinpath(root
, expanduser(str(p
))))
213 # Each target must have 'build' in the interior of the path; the
214 # directory below this will determine the build parameters. For
215 # example, for target 'foo/bar/build/X86/arch/x86/blah.do' we
216 # recognize that X86 specifies the configuration because it
217 # follow 'build' in the build path.
219 # The funky assignment to "[:]" is needed to replace the list contents
220 # in place rather than reassign the symbol to a new list, which
221 # doesn't work (obviously!).
222 BUILD_TARGETS
[:] = makePathListAbsolute(BUILD_TARGETS
)
224 # Generate a list of the unique build roots and configs that the
225 # collected targets reference.
228 for t
in BUILD_TARGETS
:
229 path_dirs
= t
.split('/')
231 build_top
= rfind(path_dirs
, 'build', -2)
233 error("No non-leaf 'build' dir found on target path.", t
)
234 this_build_root
= joinpath('/',*path_dirs
[:build_top
+1])
236 build_root
= this_build_root
238 if this_build_root
!= build_root
:
239 error("build targets not under same build root\n"
240 " %s\n %s" % (build_root
, this_build_root
))
241 variant_path
= joinpath('/',*path_dirs
[:build_top
+2])
242 if variant_path
not in variant_paths
:
243 variant_paths
.append(variant_path
)
245 # Make sure build_root exists (might not if this is the first build there)
246 if not isdir(build_root
):
248 main
['BUILDROOT'] = build_root
252 main
.SConsignFile(joinpath(build_root
, "sconsign"))
254 # Default duplicate option is to use hard links, but this messes up
255 # when you use emacs to edit a file in the target dir, as emacs moves
256 # file to file~ then copies to file, breaking the link. Symbolic
257 # (soft) links work better.
258 main
.SetOption('duplicate', 'soft-copy')
261 # Set up global sticky variables... these are common to an entire build
262 # tree (not specific to a particular build like X86)
265 global_vars_file
= joinpath(build_root
, 'variables.global')
267 global_vars
= Variables(global_vars_file
, args
=ARGUMENTS
)
269 global_vars
.AddVariables(
270 ('CC', 'C compiler', environ
.get('CC', main
['CC'])),
271 ('CXX', 'C++ compiler', environ
.get('CXX', main
['CXX'])),
272 ('CCFLAGS_EXTRA', 'Extra C and C++ compiler flags', ''),
273 ('LDFLAGS_EXTRA', 'Extra linker flags', ''),
274 ('MARSHAL_CCFLAGS_EXTRA', 'Extra C and C++ marshal compiler flags', ''),
275 ('MARSHAL_LDFLAGS_EXTRA', 'Extra marshal linker flags', ''),
276 ('PYTHON_CONFIG', 'Python config binary to use',
277 [ 'python2.7-config', 'python-config', 'python3-config' ]),
278 ('PROTOC', 'protoc tool', environ
.get('PROTOC', 'protoc')),
279 ('BATCH', 'Use batch pool for build and tests', False),
280 ('BATCH_CMD', 'Batch pool submission command name', 'qdo'),
281 ('M5_BUILD_CACHE', 'Cache built objects in this directory', False),
282 ('EXTRAS', 'Add extra directories to the compilation', '')
285 # Update main environment with values from ARGUMENTS & global_vars_file
286 global_vars
.Update(main
)
287 help_texts
["global_vars"] += global_vars
.GenerateHelpText(main
)
289 # Save sticky variable settings back to current variables file
290 global_vars
.Save(global_vars_file
, main
)
292 # Parse EXTRAS variable to build list of all directories where we're
293 # look for sources etc. This list is exported as extras_dir_list.
294 base_dir
= main
.srcdir
.abspath
296 extras_dir_list
= makePathListAbsolute(main
['EXTRAS'].split(':'))
301 Export('extras_dir_list')
303 # the ext directory should be on the #includes path
304 main
.Append(CPPPATH
=[Dir('ext')])
306 # Add shared top-level headers
307 main
.Prepend(CPPPATH
=Dir('include'))
309 if GetOption('verbose'):
310 def MakeAction(action
, string
, *args
, **kwargs
):
311 return Action(action
, *args
, **kwargs
)
314 main
['CCCOMSTR'] = Transform("CC")
315 main
['CXXCOMSTR'] = Transform("CXX")
316 main
['ASCOMSTR'] = Transform("AS")
317 main
['ARCOMSTR'] = Transform("AR", 0)
318 main
['LINKCOMSTR'] = Transform("LINK", 0)
319 main
['SHLINKCOMSTR'] = Transform("SHLINK", 0)
320 main
['RANLIBCOMSTR'] = Transform("RANLIB", 0)
321 main
['M4COMSTR'] = Transform("M4")
322 main
['SHCCCOMSTR'] = Transform("SHCC")
323 main
['SHCXXCOMSTR'] = Transform("SHCXX")
326 # Initialize the Link-Time Optimization (LTO) flags
327 main
['LTO_CCFLAGS'] = []
328 main
['LTO_LDFLAGS'] = []
330 # According to the readme, tcmalloc works best if the compiler doesn't
331 # assume that we're using the builtin malloc and friends. These flags
332 # are compiler-specific, so we need to set them after we detect which
333 # compiler we're using.
334 main
['TCMALLOC_CCFLAGS'] = []
336 CXX_version
= readCommand([main
['CXX'],'--version'], exception
=False)
337 CXX_V
= readCommand([main
['CXX'],'-V'], exception
=False)
339 main
['GCC'] = CXX_version
and CXX_version
.find('g++') >= 0
340 main
['CLANG'] = CXX_version
and CXX_version
.find('clang') >= 0
341 if main
['GCC'] + main
['CLANG'] > 1:
342 error('Two compilers enabled at once?')
344 # Set up default C++ compiler flags
345 if main
['GCC'] or main
['CLANG']:
346 # As gcc and clang share many flags, do the common parts here
347 main
.Append(CCFLAGS
=['-pipe'])
348 main
.Append(CCFLAGS
=['-fno-strict-aliasing'])
349 # Enable -Wall and -Wextra and then disable the few warnings that
350 # we consistently violate
351 main
.Append(CCFLAGS
=['-Wall', '-Wundef', '-Wextra',
352 '-Wno-sign-compare', '-Wno-unused-parameter'])
353 # We always compile using C++11
354 main
.Append(CXXFLAGS
=['-std=c++11'])
355 if sys
.platform
.startswith('freebsd'):
356 main
.Append(CCFLAGS
=['-I/usr/local/include'])
357 main
.Append(CXXFLAGS
=['-I/usr/local/include'])
359 # On Mac OS X/Darwin the default linker doesn't support the
361 if sys
.platform
!= "darwin":
362 main
.Append(LINKFLAGS
='-Wl,--as-needed')
363 main
['FILTER_PSHLINKFLAGS'] = lambda x
: str(x
).replace(' -shared', '')
364 main
['PSHLINKFLAGS'] = main
.subst('${FILTER_PSHLINKFLAGS(SHLINKFLAGS)}')
365 if GetOption('gold_linker'):
366 main
.Append(LINKFLAGS
='-fuse-ld=gold')
367 main
['PLINKFLAGS'] = main
.get('LINKFLAGS')
368 shared_partial_flags
= ['-r', '-nostdlib']
369 main
.Append(PSHLINKFLAGS
=shared_partial_flags
)
370 main
.Append(PLINKFLAGS
=shared_partial_flags
)
372 # Treat warnings as errors but white list some warnings that we
373 # want to allow (e.g., deprecation warnings).
374 main
.Append(CCFLAGS
=['-Werror',
375 '-Wno-error=deprecated-declarations',
376 '-Wno-error=deprecated',
380 "Don't know what compiler options to use for your compiler.",
381 "compiler: " + main
['CXX'],
382 "version: " + CXX_version
.replace('\n', '<nl>') if
383 CXX_version
else 'COMMAND NOT FOUND!',
384 "If you're trying to use a compiler other than GCC",
385 "or clang, there appears to be something wrong with your",
388 "If you are trying to use a compiler other than those listed",
389 "above you will need to ease fix SConstruct and ",
390 "src/SConscript to support that compiler.")))
393 # Check for a supported version of gcc. >= 4.8 is chosen for its
394 # level of c++11 support. See
395 # http://gcc.gnu.org/projects/cxx0x.html for details.
396 gcc_version
= readCommand([main
['CXX'], '-dumpversion'], exception
=False)
397 if compareVersions(gcc_version
, "4.8") < 0:
398 error('gcc version 4.8 or newer required.\n'
399 'Installed version:', gcc_version
)
402 main
['GCC_VERSION'] = gcc_version
404 if compareVersions(gcc_version
, '4.9') >= 0:
405 # Incremental linking with LTO is currently broken in gcc versions
406 # 4.9 and above. A version where everything works completely hasn't
407 # yet been identified.
409 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
410 main
['BROKEN_INCREMENTAL_LTO'] = True
411 if compareVersions(gcc_version
, '6.0') >= 0:
412 # gcc versions 6.0 and greater accept an -flinker-output flag which
413 # selects what type of output the linker should generate. This is
414 # necessary for incremental lto to work, but is also broken in
415 # current versions of gcc. It may not be necessary in future
416 # versions. We add it here since it might be, and as a reminder that
417 # it exists. It's excluded if lto is being forced.
419 # https://gcc.gnu.org/gcc-6/changes.html
420 # https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03161.html
421 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69866
422 if not GetOption('force_lto'):
423 main
.Append(PSHLINKFLAGS
='-flinker-output=rel')
424 main
.Append(PLINKFLAGS
='-flinker-output=rel')
426 disable_lto
= GetOption('no_lto')
427 if not disable_lto
and main
.get('BROKEN_INCREMENTAL_LTO', False) and \
428 not GetOption('force_lto'):
429 warning('Your compiler doesn\'t support incremental linking and lto '
430 'at the same time, so lto is being disabled. To force lto on '
431 'anyway, use the --force-lto option. That will disable '
435 # Add the appropriate Link-Time Optimization (LTO) flags
436 # unless LTO is explicitly turned off. Note that these flags
437 # are only used by the fast target.
439 # Pass the LTO flag when compiling to produce GIMPLE
440 # output, we merely create the flags here and only append
442 main
['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
444 # Use the same amount of jobs for LTO as we are running
446 main
['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs')]
448 main
.Append(TCMALLOC_CCFLAGS
=['-fno-builtin-malloc', '-fno-builtin-calloc',
449 '-fno-builtin-realloc', '-fno-builtin-free'])
452 # Check for a supported version of clang, >= 3.1 is needed to
453 # support similar features as gcc 4.8. See
454 # http://clang.llvm.org/cxx_status.html for details
455 clang_version_re
= re
.compile(".* version (\d+\.\d+)")
456 clang_version_match
= clang_version_re
.search(CXX_version
)
457 if (clang_version_match
):
458 clang_version
= clang_version_match
.groups()[0]
459 if compareVersions(clang_version
, "3.1") < 0:
460 error('clang version 3.1 or newer required.\n'
461 'Installed version:', clang_version
)
463 error('Unable to determine clang version.')
465 # clang has a few additional warnings that we disable, extraneous
466 # parantheses are allowed due to Ruby's printing of the AST,
467 # finally self assignments are allowed as the generated CPU code
469 main
.Append(CCFLAGS
=['-Wno-parentheses',
471 # Some versions of libstdc++ (4.8?) seem to
472 # use struct hash and class hash
474 '-Wno-mismatched-tags',
476 if compareVersions(clang_version
, "10.0") >= 0:
477 main
.Append(CCFLAGS
=['-Wno-c99-designator'])
479 if compareVersions(clang_version
, "8.0") >= 0:
480 main
.Append(CCFLAGS
=['-Wno-defaulted-function-deleted'])
482 main
.Append(TCMALLOC_CCFLAGS
=['-fno-builtin'])
484 # On Mac OS X/Darwin we need to also use libc++ (part of XCode) as
485 # opposed to libstdc++, as the later is dated.
486 if sys
.platform
== "darwin":
487 main
.Append(CXXFLAGS
=['-stdlib=libc++'])
488 main
.Append(LIBS
=['c++'])
490 # On FreeBSD we need libthr.
491 if sys
.platform
.startswith('freebsd'):
492 main
.Append(LIBS
=['thr'])
494 # Add sanitizers flags
496 if GetOption('with_ubsan'):
497 # Only gcc >= 4.9 supports UBSan, so check both the version
498 # and the command-line option before adding the compiler and
500 if not main
['GCC'] or compareVersions(main
['GCC_VERSION'], '4.9') >= 0:
501 sanitizers
.append('undefined')
502 if GetOption('with_asan'):
503 # Available for gcc >= 4.8 or llvm >= 3.1 both a requirement
504 # by the build system
505 sanitizers
.append('address')
506 suppressions_file
= Dir('util').File('lsan-suppressions').get_abspath()
507 suppressions_opt
= 'suppressions=%s' % suppressions_file
508 main
['ENV']['LSAN_OPTIONS'] = ':'.join([suppressions_opt
,
509 'print_suppressions=0'])
511 warning('To suppress false positive leaks, set the LSAN_OPTIONS '
512 'environment variable to "%s" when running gem5' %
514 warning('LSAN_OPTIONS=suppressions=%s' % suppressions_opt
)
517 sanitizers
= ','.join(sanitizers
)
518 if main
['GCC'] or main
['CLANG']:
519 main
.Append(CCFLAGS
=['-fsanitize=%s' % sanitizers
,
520 '-fno-omit-frame-pointer'],
521 LINKFLAGS
='-fsanitize=%s' % sanitizers
)
523 warning("Don't know how to enable %s sanitizer(s) for your "
524 "compiler." % sanitizers
)
526 # Set up common yacc/bison flags (needed for Ruby)
527 main
['YACCFLAGS'] = '-d'
528 main
['YACCHXXFILESUFFIX'] = '.hh'
530 # Do this after we save setting back, or else we'll tack on an
531 # extra 'qdo' every time we run scons.
533 main
['CC'] = main
['BATCH_CMD'] + ' ' + main
['CC']
534 main
['CXX'] = main
['BATCH_CMD'] + ' ' + main
['CXX']
535 main
['AS'] = main
['BATCH_CMD'] + ' ' + main
['AS']
536 main
['AR'] = main
['BATCH_CMD'] + ' ' + main
['AR']
537 main
['RANLIB'] = main
['BATCH_CMD'] + ' ' + main
['RANLIB']
539 if sys
.platform
== 'cygwin':
540 # cygwin has some header file issues...
541 main
.Append(CCFLAGS
=["-Wno-uninitialized"])
544 have_pkg_config
= readCommand(['pkg-config', '--version'], exception
='')
546 # Check for the protobuf compiler
548 main
['HAVE_PROTOC'] = True
549 protoc_version
= readCommand([main
['PROTOC'], '--version']).split()
551 # First two words should be "libprotoc x.y.z"
552 if len(protoc_version
) < 2 or protoc_version
[0] != 'libprotoc':
553 warning('Protocol buffer compiler (protoc) not found.\n'
554 'Please install protobuf-compiler for tracing support.')
555 main
['HAVE_PROTOC'] = False
557 # Based on the availability of the compress stream wrappers,
559 min_protoc_version
= '2.1.0'
560 if compareVersions(protoc_version
[1], min_protoc_version
) < 0:
561 warning('protoc version', min_protoc_version
,
562 'or newer required.\n'
563 'Installed version:', protoc_version
[1])
564 main
['HAVE_PROTOC'] = False
566 # Attempt to determine the appropriate include path and
567 # library path using pkg-config, that means we also need to
568 # check for pkg-config. Note that it is possible to use
569 # protobuf without the involvement of pkg-config. Later on we
570 # check go a library config check and at that point the test
571 # will fail if libprotobuf cannot be found.
574 # Attempt to establish what linking flags to add for
578 'pkg-config --cflags --libs-only-L protobuf')
580 warning('pkg-config could not get protobuf flags.')
581 except Exception as e
:
582 warning('While checking protoc version:', str(e
))
583 main
['HAVE_PROTOC'] = False
585 # Check for 'timeout' from GNU coreutils. If present, regressions will
586 # be run with a time limit. We require version 8.13 since we rely on
587 # support for the '--foreground' option.
588 if sys
.platform
.startswith('freebsd'):
589 timeout_lines
= readCommand(['gtimeout', '--version'],
590 exception
='').splitlines()
592 timeout_lines
= readCommand(['timeout', '--version'],
593 exception
='').splitlines()
594 # Get the first line and tokenize it
595 timeout_version
= timeout_lines
[0].split() if timeout_lines
else []
596 main
['TIMEOUT'] = timeout_version
and \
597 compareVersions(timeout_version
[-1], '8.13') >= 0
599 # Add a custom Check function to test for structure members.
600 def CheckMember(context
, include
, decl
, member
, include_quotes
="<>"):
601 context
.Message("Checking for member %s in %s..." %
607 (void)test.%(member)s;
610 """ % { "header" : include_quotes
[0] + include
+ include_quotes
[1],
615 ret
= context
.TryCompile(text
, extension
=".cc")
619 # Platform-specific configuration. Note again that we assume that all
620 # builds under a given build root run on the same host platform.
621 conf
= Configure(main
,
622 conf_dir
= joinpath(build_root
, '.scons_config'),
623 log_file
= joinpath(build_root
, 'scons_config.log'),
625 'CheckMember' : CheckMember
,
628 # Check if we should compile a 64 bit binary on Mac OS X/Darwin
631 uname
= platform
.uname()
632 if uname
[0] == 'Darwin' and compareVersions(uname
[2], '9.0.0') >= 0:
633 if int(readCommand('sysctl -n hw.cpu64bit_capable')[0]):
634 main
.Append(CCFLAGS
=['-arch', 'x86_64'])
635 main
.Append(CFLAGS
=['-arch', 'x86_64'])
636 main
.Append(LINKFLAGS
=['-arch', 'x86_64'])
637 main
.Append(ASFLAGS
=['-arch', 'x86_64'])
641 # Recent versions of scons substitute a "Null" object for Configure()
642 # when configuration isn't necessary, e.g., if the "--help" option is
643 # present. Unfortuantely this Null object always returns false,
644 # breaking all our configuration checks. We replace it with our own
645 # more optimistic null object that returns True instead.
647 def NullCheck(*args
, **kwargs
):
651 def __init__(self
, env
):
655 def __getattr__(self
, mname
):
658 conf
= NullConf(main
)
660 # Cache build files in the supplied directory.
661 if main
['M5_BUILD_CACHE']:
662 print('Using build cache located at', main
['M5_BUILD_CACHE'])
663 CacheDir(main
['M5_BUILD_CACHE'])
665 main
['USE_PYTHON'] = not GetOption('without_python')
666 if main
['USE_PYTHON']:
667 # Find Python include and library directories for embedding the
668 # interpreter. We rely on python-config to resolve the appropriate
669 # includes and linker flags. ParseConfig does not seem to understand
670 # the more exotic linker flags such as -Xlinker and -export-dynamic so
671 # we add them explicitly below. If you want to link in an alternate
672 # version of python, see above for instructions on how to invoke
673 # scons with the appropriate PATH set.
675 python_config
= main
.Detect(main
['PYTHON_CONFIG'])
676 if python_config
is None:
677 error("Can't find a suitable python-config, tried %s" % \
678 main
['PYTHON_CONFIG'])
680 print("Info: Using Python config: %s" % (python_config
, ))
681 py_includes
= readCommand([python_config
, '--includes'],
682 exception
='').split()
683 py_includes
= list(filter(
684 lambda s
: match(r
'.*\/include\/.*',s
), py_includes
))
685 # Strip the -I from the include folders before adding them to the
687 py_includes
= list(map(
688 lambda s
: s
[2:] if s
.startswith('-I') else s
, py_includes
))
689 main
.Append(CPPPATH
=py_includes
)
691 # Read the linker flags and split them into libraries and other link
692 # flags. The libraries are added later through the call the CheckLib.
693 # Note: starting in Python 3.8 the --embed flag is required to get the
694 # -lpython3.8 linker flag
695 retcode
, cmd_stdout
= readCommandWithReturn(
696 [python_config
, '--ldflags', '--embed'], exception
='')
698 # If --embed isn't detected then we're running python <3.8
699 retcode
, cmd_stdout
= readCommandWithReturn(
700 [python_config
, '--ldflags'], exception
='')
702 # Checking retcode again
704 error("Failing on python-config --ldflags command")
706 py_ld_flags
= cmd_stdout
.split()
709 for lib
in py_ld_flags
:
710 if not lib
.startswith('-l'):
711 main
.Append(LINKFLAGS
=[lib
])
714 if lib
not in py_libs
:
717 # verify that this stuff works
718 if not conf
.CheckHeader('Python.h', '<>'):
719 error("Check failed for Python.h header in",
720 ' '.join(py_includes
), "\n"
721 "Two possible reasons:\n"
722 "1. Python headers are not installed (You can install the "
723 "package python-dev on Ubuntu and RedHat)\n"
724 "2. SCons is using a wrong C compiler. This can happen if "
725 "CC has the wrong value.\n"
726 "CC = %s" % main
['CC'])
729 if not conf
.CheckLib(lib
):
730 error("Can't find library %s required by python." % lib
)
732 main
.Prepend(CPPPATH
=Dir('ext/pybind11/include/'))
733 # Bare minimum environment that only includes python
734 marshal_env
= main
.Clone()
735 marshal_env
.Append(CCFLAGS
='$MARSHAL_CCFLAGS_EXTRA')
736 marshal_env
.Append(LINKFLAGS
='$MARSHAL_LDFLAGS_EXTRA')
738 # On Solaris you need to use libsocket for socket ops
739 if not conf
.CheckLibWithHeader(None, 'sys/socket.h', 'C++', 'accept(0,0,0);'):
740 if not conf
.CheckLibWithHeader('socket', 'sys/socket.h',
741 'C++', 'accept(0,0,0);'):
742 error("Can't find library with socket calls (e.g. accept()).")
744 # Check for zlib. If the check passes, libz will be automatically
745 # added to the LIBS environment variable.
746 if not conf
.CheckLibWithHeader('z', 'zlib.h', 'C++','zlibVersion();'):
747 error('Did not find needed zlib compression library '
748 'and/or zlib.h header file.\n'
749 'Please install zlib and try again.')
751 # If we have the protobuf compiler, also make sure we have the
752 # development libraries. If the check passes, libprotobuf will be
753 # automatically added to the LIBS environment variable. After
754 # this, we can use the HAVE_PROTOBUF flag to determine if we have
755 # got both protoc and libprotobuf available.
756 main
['HAVE_PROTOBUF'] = main
['HAVE_PROTOC'] and \
757 conf
.CheckLibWithHeader('protobuf', 'google/protobuf/message.h',
758 'C++', 'GOOGLE_PROTOBUF_VERIFY_VERSION;')
760 # Valgrind gets much less confused if you tell it when you're using
761 # alternative stacks.
762 main
['HAVE_VALGRIND'] = conf
.CheckCHeader('valgrind/valgrind.h')
764 # If we have the compiler but not the library, print another warning.
765 if main
['HAVE_PROTOC'] and not main
['HAVE_PROTOBUF']:
766 warning('Did not find protocol buffer library and/or headers.\n'
767 'Please install libprotobuf-dev for tracing support.')
771 conf
.CheckLibWithHeader(None, 'time.h', 'C',
772 'clock_nanosleep(0,0,NULL,NULL);') or \
773 conf
.CheckLibWithHeader('rt', 'time.h', 'C',
774 'clock_nanosleep(0,0,NULL,NULL);')
776 have_posix_timers
= \
777 conf
.CheckLibWithHeader([None, 'rt'], [ 'time.h', 'signal.h' ], 'C',
778 'timer_create(CLOCK_MONOTONIC, NULL, NULL);')
780 if not GetOption('without_tcmalloc'):
781 if conf
.CheckLib('tcmalloc'):
782 main
.Append(CCFLAGS
=main
['TCMALLOC_CCFLAGS'])
783 elif conf
.CheckLib('tcmalloc_minimal'):
784 main
.Append(CCFLAGS
=main
['TCMALLOC_CCFLAGS'])
786 warning("You can get a 12% performance improvement by "
787 "installing tcmalloc (libgoogle-perftools-dev package "
788 "on Ubuntu or RedHat).")
791 # Detect back trace implementations. The last implementation in the
792 # list will be used by default.
793 backtrace_impls
= [ "none" ]
795 backtrace_checker
= 'char temp;' + \
796 ' backtrace_symbols_fd((void*)&temp, 0, 0);'
797 if conf
.CheckLibWithHeader(None, 'execinfo.h', 'C', backtrace_checker
):
798 backtrace_impls
.append("glibc")
799 elif conf
.CheckLibWithHeader('execinfo', 'execinfo.h', 'C',
801 # NetBSD and FreeBSD need libexecinfo.
802 backtrace_impls
.append("glibc")
803 main
.Append(LIBS
=['execinfo'])
805 if backtrace_impls
[-1] == "none":
806 default_backtrace_impl
= "none"
807 warning("No suitable back trace implementation found.")
809 if not have_posix_clock
:
810 warning("Can't find library for POSIX clocks.")
812 # Check for <fenv.h> (C99 FP environment control)
813 have_fenv
= conf
.CheckHeader('fenv.h', '<>')
815 warning("Header file <fenv.h> not found.\n"
816 "This host has no IEEE FP rounding mode control.")
818 # Check for <png.h> (libpng library needed if wanting to dump
819 # frame buffer image in png format)
820 have_png
= conf
.CheckHeader('png.h', '<>')
822 warning("Header file <png.h> not found.\n"
823 "This host has no libpng library.\n"
824 "Disabling support for PNG framebuffers.")
826 # Check if we should enable KVM-based hardware virtualization. The API
827 # we rely on exists since version 2.6.36 of the kernel, but somehow
828 # the KVM_API_VERSION does not reflect the change. We test for one of
829 # the types as a fall back.
830 have_kvm
= conf
.CheckHeader('linux/kvm.h', '<>')
832 print("Info: Compatible header file <linux/kvm.h> not found, "
833 "disabling KVM support.")
835 # Check if the TUN/TAP driver is available.
836 have_tuntap
= conf
.CheckHeader('linux/if_tun.h', '<>')
838 print("Info: Compatible header file <linux/if_tun.h> not found.")
840 # x86 needs support for xsave. We test for the structure here since we
841 # won't be able to run new tests by the time we know which ISA we're
843 have_kvm_xsave
= conf
.CheckTypeSize('struct kvm_xsave',
844 '#include <linux/kvm.h>') != 0
846 # Check if the requested target ISA is compatible with the host
847 def is_isa_kvm_compatible(isa
):
850 host_isa
= platform
.machine()
852 warning("Failed to determine host ISA.")
855 if not have_posix_timers
:
856 warning("Can not enable KVM, host seems to lack support "
861 return host_isa
in ( "armv7l", "aarch64" )
863 if host_isa
!= "x86_64":
866 if not have_kvm_xsave
:
867 warning("KVM on x86 requires xsave support in kernel headers.")
875 # Check if the exclude_host attribute is available. We want this to
876 # get accurate instruction counts in KVM.
877 main
['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf
.CheckMember(
878 'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
882 conf
.CheckLibWithHeader('hdf5', 'hdf5.h', 'C',
883 'H5Fcreate("", 0, 0, 0);') and \
884 conf
.CheckLibWithHeader('hdf5_cpp', 'H5Cpp.h', 'C++',
885 'H5::H5File("", 0);')
887 def check_hdf5_pkg(name
):
888 print("Checking for %s using pkg-config..." % name
, end
="")
889 if not have_pkg_config
:
890 print(" pkg-config not found")
894 main
.ParseConfig('pkg-config --cflags-only-I --libs-only-L %s' % name
)
901 # Check if there is a pkg-config configuration for hdf5. If we find
902 # it, setup the environment to enable linking and header inclusion. We
903 # don't actually try to include any headers or link with hdf5 at this
905 if not check_hdf5_pkg('hdf5-serial'):
906 check_hdf5_pkg('hdf5')
908 # Check if the HDF5 libraries can be found. This check respects the
909 # include path and library path provided by pkg-config. We perform
910 # this check even if there isn't a pkg-config configuration for hdf5
911 # since some installations don't use pkg-config.
912 have_hdf5
= check_hdf5()
914 print("Warning: Couldn't find any HDF5 C++ libraries. Disabling")
915 print(" HDF5 support.")
917 ######################################################################
919 # Finish the configuration
923 ######################################################################
925 # Collect all non-global variables
928 # Define the universe of supported ISAs
930 all_gpu_isa_list
= [ ]
931 Export('all_isa_list')
932 Export('all_gpu_isa_list')
934 class CpuModel(object):
935 '''The CpuModel class encapsulates everything the ISA parser needs to
936 know about a particular CPU model.'''
938 # Dict of available CPU model objects. Accessible as CpuModel.dict.
941 # Constructor. Automatically adds models to CpuModel.dict.
942 def __init__(self
, name
, default
=False):
943 self
.name
= name
# name of model
945 # This cpu is enabled by default
946 self
.default
= default
949 if name
in CpuModel
.dict:
950 raise AttributeError("CpuModel '%s' already registered" % name
)
951 CpuModel
.dict[name
] = self
955 # Sticky variables get saved in the variables file so they persist from
956 # one invocation to the next (unless overridden, in which case the new
957 # value becomes sticky).
958 sticky_vars
= Variables(args
=ARGUMENTS
)
959 Export('sticky_vars')
961 # Sticky variables that should be exported
963 Export('export_vars')
967 Export('all_protocols')
969 Export('protocol_dirs')
971 Export('slicc_includes')
973 # Walk the tree and execute all SConsopts scripts that wil add to the
975 if GetOption('verbose'):
976 print("Reading SConsopts")
977 for bdir
in [ base_dir
] + extras_dir_list
:
979 error("Directory '%s' does not exist." % bdir
)
980 for root
, dirs
, files
in os
.walk(bdir
):
981 if 'SConsopts' in files
:
982 if GetOption('verbose'):
983 print("Reading", joinpath(root
, 'SConsopts'))
984 SConscript(joinpath(root
, 'SConsopts'))
987 all_gpu_isa_list
.sort()
989 sticky_vars
.AddVariables(
990 EnumVariable('TARGET_ISA', 'Target ISA', 'null', all_isa_list
),
991 EnumVariable('TARGET_GPU_ISA', 'Target GPU ISA', 'gcn3', all_gpu_isa_list
),
992 ListVariable('CPU_MODELS', 'CPU models',
993 sorted(n
for n
,m
in CpuModel
.dict.items() if m
.default
),
994 sorted(CpuModel
.dict.keys())),
995 BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
997 BoolVariable('USE_SSE2',
998 'Compile for SSE2 (-msse2) to get IEEE FP on x86 hosts',
1000 BoolVariable('USE_POSIX_CLOCK', 'Use POSIX Clocks', have_posix_clock
),
1001 BoolVariable('USE_FENV', 'Use <fenv.h> IEEE mode control', have_fenv
),
1002 BoolVariable('USE_PNG', 'Enable support for PNG images', have_png
),
1003 BoolVariable('CP_ANNOTATE', 'Enable critical path annotation capability',
1005 BoolVariable('USE_KVM', 'Enable hardware virtualized (KVM) CPU models',
1007 BoolVariable('USE_TUNTAP',
1008 'Enable using a tap device to bridge to the host network',
1010 BoolVariable('BUILD_GPU', 'Build the compute-GPU model', False),
1011 EnumVariable('PROTOCOL', 'Coherence protocol for Ruby', 'None',
1013 EnumVariable('BACKTRACE_IMPL', 'Post-mortem dump implementation',
1014 backtrace_impls
[-1], backtrace_impls
),
1015 ('NUMBER_BITS_PER_SET', 'Max elements in set (default 64)',
1017 BoolVariable('USE_HDF5', 'Enable the HDF5 support', have_hdf5
),
1020 # These variables get exported to #defines in config/*.hh (see src/SConscript).
1021 export_vars
+= ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
1022 'USE_POSIX_CLOCK', 'USE_KVM', 'USE_TUNTAP', 'PROTOCOL',
1023 'HAVE_PROTOBUF', 'HAVE_VALGRIND',
1024 'HAVE_PERF_ATTR_EXCLUDE_HOST', 'USE_PNG',
1025 'NUMBER_BITS_PER_SET', 'USE_HDF5']
1027 ###################################################
1029 # Define a SCons builder for configuration flag headers.
1031 ###################################################
1033 # This function generates a config header file that #defines the
1034 # variable symbol to the current variable setting (0 or 1). The source
1035 # operands are the name of the variable and a Value node containing the
1036 # value of the variable.
1037 def build_config_file(target
, source
, env
):
1038 (variable
, value
) = [s
.get_contents().decode('utf-8') for s
in source
]
1039 with
open(str(target
[0]), 'w') as f
:
1040 print('#define', variable
, value
, file=f
)
1043 # Combine the two functions into a scons Action object.
1044 config_action
= MakeAction(build_config_file
, Transform("CONFIG H", 2))
1046 # The emitter munges the source & target node lists to reflect what
1047 # we're really doing.
1048 def config_emitter(target
, source
, env
):
1049 # extract variable name from Builder arg
1050 variable
= str(target
[0])
1051 # True target is config header file
1052 target
= joinpath('config', variable
.lower() + '.hh')
1054 if isinstance(val
, bool):
1055 # Force value to 0/1
1057 elif isinstance(val
, str):
1058 val
= '"' + val
+ '"'
1060 # Sources are variable name & value (packaged in SCons Value nodes)
1061 return ([target
], [Value(variable
), Value(val
)])
1063 config_builder
= Builder(emitter
= config_emitter
, action
= config_action
)
1065 main
.Append(BUILDERS
= { 'ConfigFile' : config_builder
})
1067 ###################################################
1069 # Builders for static and shared partially linked object files.
1071 ###################################################
1073 partial_static_builder
= Builder(action
=SCons
.Defaults
.LinkAction
,
1074 src_suffix
='$OBJSUFFIX',
1075 src_builder
=['StaticObject', 'Object'],
1076 LINKFLAGS
='$PLINKFLAGS',
1079 def partial_shared_emitter(target
, source
, env
):
1081 tgt
.attributes
.shared
= 1
1082 return (target
, source
)
1083 partial_shared_builder
= Builder(action
=SCons
.Defaults
.ShLinkAction
,
1084 emitter
=partial_shared_emitter
,
1085 src_suffix
='$SHOBJSUFFIX',
1086 src_builder
='SharedObject',
1087 SHLINKFLAGS
='$PSHLINKFLAGS',
1090 main
.Append(BUILDERS
= { 'PartialShared' : partial_shared_builder
,
1091 'PartialStatic' : partial_static_builder
})
1093 def add_local_rpath(env
, *targets
):
1094 '''Set up an RPATH for a library which lives in the build directory.
1096 The construction environment variable BIN_RPATH_PREFIX should be set to
1097 the relative path of the build directory starting from the location of the
1099 for target
in targets
:
1100 target
= env
.Entry(target
)
1101 if not isinstance(target
, SCons
.Node
.FS
.Dir
):
1103 relpath
= os
.path
.relpath(target
.abspath
, env
['BUILDDIR'])
1106 '${BIN_RPATH_PREFIX}',
1109 env
.Append(RPATH
=[env
.Literal(os
.path
.join(*components
))])
1111 if sys
.platform
!= "darwin":
1112 main
.Append(LINKFLAGS
=Split('-z origin'))
1114 main
.AddMethod(add_local_rpath
, 'AddLocalRPATH')
1116 # builds in ext are shared across all configs in the build root.
1117 ext_dir
= abspath(joinpath(str(main
.root
), 'ext'))
1119 for root
, dirs
, files
in os
.walk(ext_dir
):
1120 if 'SConscript' in files
:
1121 build_dir
= os
.path
.relpath(root
, ext_dir
)
1122 ext_build_dirs
.append(build_dir
)
1123 main
.SConscript(joinpath(root
, 'SConscript'),
1124 variant_dir
=joinpath(build_root
, build_dir
))
1126 gdb_xml_dir
= joinpath(ext_dir
, 'gdb-xml')
1127 Export('gdb_xml_dir')
1129 ###################################################
1131 # This builder and wrapper method are used to set up a directory with
1132 # switching headers. Those are headers which are in a generic location and
1133 # that include more specific headers from a directory chosen at build time
1134 # based on the current build settings.
1136 ###################################################
1138 def build_switching_header(target
, source
, env
):
1139 path
= str(target
[0])
1140 subdir
= str(source
[0])
1141 dp
, fp
= os
.path
.split(path
)
1142 dp
= os
.path
.relpath(os
.path
.realpath(dp
),
1143 os
.path
.realpath(env
['BUILDDIR']))
1144 with
open(path
, 'w') as hdr
:
1145 print('#include "%s/%s/%s"' % (dp
, subdir
, fp
), file=hdr
)
1147 switching_header_action
= MakeAction(build_switching_header
,
1148 Transform('GENERATE'))
1150 switching_header_builder
= Builder(action
=switching_header_action
,
1151 source_factory
=Value
,
1154 main
.Append(BUILDERS
= { 'SwitchingHeader': switching_header_builder
})
1156 def switching_headers(self
, headers
, source
):
1157 for header
in headers
:
1158 self
.SwitchingHeader(header
, source
)
1160 main
.AddMethod(switching_headers
, 'SwitchingHeaders')
1162 ###################################################
1164 # Define build environments for selected configurations.
1166 ###################################################
1168 for variant_path
in variant_paths
:
1169 if not GetOption('silent'):
1170 print("Building in", variant_path
)
1172 # Make a copy of the build-root environment to use for this config.
1174 env
['BUILDDIR'] = variant_path
1176 # variant_dir is the tail component of build path, and is used to
1177 # determine the build parameters (e.g., 'X86')
1178 (build_root
, variant_dir
) = splitpath(variant_path
)
1180 # Set env variables according to the build directory config.
1181 sticky_vars
.files
= []
1182 # Variables for $BUILD_ROOT/$VARIANT_DIR are stored in
1183 # $BUILD_ROOT/variables/$VARIANT_DIR so you can nuke
1184 # $BUILD_ROOT/$VARIANT_DIR without losing your variables settings.
1185 current_vars_file
= joinpath(build_root
, 'variables', variant_dir
)
1186 if isfile(current_vars_file
):
1187 sticky_vars
.files
.append(current_vars_file
)
1188 if not GetOption('silent'):
1189 print("Using saved variables file %s" % current_vars_file
)
1190 elif variant_dir
in ext_build_dirs
:
1191 # Things in ext are built without a variant directory.
1194 # Build dir-specific variables file doesn't exist.
1196 # Make sure the directory is there so we can create it later
1197 opt_dir
= dirname(current_vars_file
)
1198 if not isdir(opt_dir
):
1201 # Get default build variables from source tree. Variables are
1202 # normally determined by name of $VARIANT_DIR, but can be
1203 # overridden by '--default=' arg on command line.
1204 default
= GetOption('default')
1205 opts_dir
= joinpath(main
.root
.abspath
, 'build_opts')
1207 default_vars_files
= [joinpath(build_root
, 'variables', default
),
1208 joinpath(opts_dir
, default
)]
1210 default_vars_files
= [joinpath(opts_dir
, variant_dir
)]
1211 existing_files
= list(filter(isfile
, default_vars_files
))
1213 default_vars_file
= existing_files
[0]
1214 sticky_vars
.files
.append(default_vars_file
)
1215 print("Variables file %s not found,\n using defaults in %s"
1216 % (current_vars_file
, default_vars_file
))
1218 error("Cannot find variables file %s or default file(s) %s"
1219 % (current_vars_file
, ' or '.join(default_vars_files
)))
1222 # Apply current variable settings to env
1223 sticky_vars
.Update(env
)
1225 help_texts
["local_vars"] += \
1226 "Build variables for %s:\n" % variant_dir \
1227 + sticky_vars
.GenerateHelpText(env
)
1229 # Process variable settings.
1231 if not have_fenv
and env
['USE_FENV']:
1232 warning("<fenv.h> not available; forcing USE_FENV to False in",
1234 env
['USE_FENV'] = False
1236 if not env
['USE_FENV']:
1237 warning("No IEEE FP rounding mode control in", variant_dir
+ ".\n"
1238 "FP results may deviate slightly from other platforms.")
1240 if not have_png
and env
['USE_PNG']:
1241 warning("<png.h> not available; forcing USE_PNG to False in",
1243 env
['USE_PNG'] = False
1246 env
.Append(LIBS
=['png'])
1249 env
.Append(LIBS
=['efence'])
1253 warning("Can not enable KVM, host seems to lack KVM support")
1254 env
['USE_KVM'] = False
1255 elif not is_isa_kvm_compatible(env
['TARGET_ISA']):
1256 print("Info: KVM support disabled due to unsupported host and "
1257 "target ISA combination")
1258 env
['USE_KVM'] = False
1260 if env
['USE_TUNTAP']:
1262 warning("Can't connect EtherTap with a tap device.")
1263 env
['USE_TUNTAP'] = False
1265 if env
['BUILD_GPU']:
1266 env
.Append(CPPDEFINES
=['BUILD_GPU'])
1268 # Warn about missing optional functionality
1270 if not main
['HAVE_PERF_ATTR_EXCLUDE_HOST']:
1271 warning("perf_event headers lack support for the exclude_host "
1272 "attribute. KVM instruction counts will be inaccurate.")
1274 # Save sticky variable settings back to current variables file
1275 sticky_vars
.Save(current_vars_file
, env
)
1278 env
.Append(CCFLAGS
=['-msse2'])
1280 env
.Append(CCFLAGS
='$CCFLAGS_EXTRA')
1281 env
.Append(LINKFLAGS
='$LDFLAGS_EXTRA')
1283 # The src/SConscript file sets up the build rules in 'env' according
1284 # to the configured variables. It returns a list of environments,
1285 # one for each variant build (debug, opt, etc.)
1286 SConscript('src/SConscript', variant_dir
=variant_path
,
1287 exports
=['env', 'marshal_env'])
1291 Usage: scons [scons options] [build variables] [target(s)]
1293 Extra scons options:
1296 Global build variables:
1302 atexit
.register(summarize_warnings
)