Consider a user on his Mac, who wants to cross-compile for his Linux ARM device:
./configure --dest-cpu=arm --dest-os=linux
Before this patch, for example, DTrace probes would incorrectly attempt to be
enabled because the configure script is running on a MacOS machine, even though
we're trying to compile a binary for `linux`.
With this patch, the `--dest-os` flag is respected throughout the configure
script, thus leaving DTrace probes disabled in this cross-compiling scenario.
When building custom `node` versions (e.g., floating features/fixes from
different versions) it's often useful to specify a custom tag which
easily identifies build when invoking `node -v`.
Introduce a way to specify this tag in `node_version.h` file or by
running `./configure --tag="<tag>"`. Insert it right after the patch
version (and before `-pre`, if build is not a release).
Closes #4452.
DTrace on Linux should not be enabled by default because not all systems will
have the proper headers installed. Only enable when --with-dtrace is passed to
the configure script.
Unconditionally compile V8 with -fno-strict-aliasing on all platforms.
gcc 4.5.2 on sunos generates bad code when -fstrict-aliasing is enabled, which
undoubtedly means that there are more buggy versions of gcc out there.
-fstrict-aliasing does not give a significant performance boost so let's just
disable it.
Fixes #3736.
V8 on ARM requires that armv7 is set. We don't have a good way to detect the
CPU model right now so we pick a default and hope that it works okay for the
majority of people.
Non-scientific sampling - the ARM hardware I have lying around the house -
suggests that ARMv5 and ARMv6 are still most common so armv7=0 it is.
This obviously needs to be revisited sometime in the future.
Compile at -O2 and disable optimizations that trigger gcc bugs.
Some people still reported mksnapshot crashes after commit b40f813 ("build: fix
spurious mksnapshot crashes for good" - so much for that).
Average performance of the -O2 binary is on par with the -O3 binary. Variance
on the http_simple bytes/8 benchmark appears to be slightly greater but small
enough that the possibly of it being noise cannot be excluded.
The new binary very slightly but consistently outperforms the -O3 binary (by
about 0.5%) on the mostly CPU-bound bytes/102400 benchmark. That could be an
artifact of the system I benchmarked it on, a Core 2 Duo with a puny 32 kB of
L1 instruction cache. The smaller binary seems to play nicer with the cache.
A variety of gcc bugs made mksnapshot crash with either a segmentation fault
or a 'pure virtual method callled' run-time error.
After much wailing and gnashing of teeth I managed to deduce that the bugs
show up when:
1. gcc 4.5.2 for i386-pc-solaris2.11 is used and -fstrict-aliasing is
enabled, or
2. gcc version 4.4.6 for x86_64-redhat-linux is used and
-ffunction-sections -finline-functions at -O2 or higher is enabled
Therefore, disable -ffunction-sections and -fdata-sections unconditionally
and disable -fstrict-aliasing only on Solaris.
The -ffunction-sections and -fdata-sections switches were nonsense anyway
because we don't link with -Wl,--gc-sections.
It has been conclusively demonstrated that the -fstrict-aliasing bugs in gcc's
optimizer are not limited to the 4.5.x releases only.
Fixes #3601 among others.
The heuristic introduced in f78ce08 ("build: handle output of localized gcc or
clang") does not handle "branded" versions of gcc, i.e. a gcc whose output has
been customized by the distro vendor.
Fixes #3601.
Before this commit, we used to scan the output of `$CC -v` for strings like
"gcc version x.y.z".
It was pointed out that this approach fails with localized versions of gcc
because those print (for example) "gcc versión x.y.z".
Use the output of `$CC --version` instead and only look at the first line.
For consistency's sake, rename:
--openssl-use-sys
--openssl-includes
--openssl-libpath
To:
--shared-openssl
--shared-openssl-includes
--shared-openssl-libpath
And add --shared-openssl-libname while we're at it.
The old switches still work but `./configure --help` won't print them.
Fixes #3591.
Make configure start gyp with the same python interpreter that is used to
run configure itself.
Fixes an issue where configure fails with a SyntaxError because the user
has multiple python binaries on his $PATH and the default one is too old.
