build/gen.py: Add --link-lib=LINK_LIB option.
This adds one new command-line option to the build/gen.py
script to allow linking the final executable(s) with one or
more extra libraries.
This is mostly useful to link a custom malloc implementation
or a cpu profiling library, like libtcmalloc.a or libprofiler.a
provided by the the gperftools project [1].
For the record, using:
build/gen.py --use-icf --use-lto --link-lib=/path/to/libtcmalloc.a
Results in a noticeably faster GN executable for both Chromium
(21% faster) and the Fuchsia build (43% faster!)
It is also possible to link against a more recent release of TCMalloc
from [2], but measurements show no noticeable performance difference
with the older release for GN workloads.
Chromium:
BEFORE: Done. Made 13124 targets from 2289 files in 3593ms
AFTER: Done. Made 13124 targets from 2289 files in 4358ms
Fuchsia:
BEFORE: [...] Done. Made 47263 targets from 3819 files in 14263ms
AFTER: [...] Done. Made 47263 targets from 3819 files in 9923ms
[1] https://github.com/gperftools/gperftools
[2] https://github.com/google/tcmalloc
Change-Id: If21911f13a886eeae09797099a078ed1d4f789dd
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/8360
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: David Turner <digit@google.com>
diff --git a/build/gen.py b/build/gen.py
index 8083aac..a00558b 100755
--- a/build/gen.py
+++ b/build/gen.py
@@ -15,6 +15,11 @@
import sys
import tempfile
+try: # py3
+ from shlex import quote as shell_quote
+except ImportError: # py2
+ from pipes import quote as shell_quote
+
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
REPO_ROOT = os.path.dirname(SCRIPT_DIR)
@@ -102,6 +107,16 @@
parser.add_option('--no-static-libstdc++', action='store_true',
default=False, dest='no_static_libstdcpp',
help='Don\'t link libstdc++ statically')
+ parser.add_option('--link-lib',
+ action='append',
+ metavar='LINK_LIB',
+ default=[],
+ dest='link_libs',
+ help=('Add a library to the final executable link. ' +
+ 'LINK_LIB must be the path to a static or shared ' +
+ 'library, or \'-l<name>\' on POSIX systems. Can be ' +
+ 'used multiple times. Useful to link custom malloc ' +
+ 'or cpu profiling libraries.'))
options, args = parser.parse_args(argv)
if args:
@@ -159,14 +174,17 @@
cxx, ar, ld, platform, host, options,
cflags=[], ldflags=[], libflags=[],
include_dirs=[], solibs=[]):
+ args = ' -d' if options.debug else ''
+ for link_lib in options.link_libs:
+ args += ' --link-lib=' + shell_quote(link_lib)
+
ninja_header_lines = [
'cxx = ' + cxx,
'ar = ' + ar,
'ld = ' + ld,
'',
'rule regen',
- ' command = %s ../build/gen.py%s' % (
- sys.executable, ' -d' if options.debug else ''),
+ ' command = %s ../build/gen.py%s' % (sys.executable, args),
' description = Regenerating ninja files',
'',
'build build.ninja: regen',
@@ -734,6 +752,8 @@
])
+ libs.extend(options.link_libs)
+
# we just build static libraries that GN needs
executables['gn']['libs'].extend(static_libraries.keys())
executables['gn_unittests']['libs'].extend(static_libraries.keys())
