use_lld defaults to true on non-mac if clang_base_path is set (i.e.
the host compiler is a locally-built clang). On mac, the lld Mach-O
port used to be unusable, but ld64.lld.darwinnew is close to usable.
When explicitly setting `use_lld = true` in a GN build on a mac host,
check-lld passes, two check-clang tests fail, and a handful check-llvm
tests fail (the latter all due to -flat_namespace not yet being implemented).
This will hopefully fix the build not becoming clean when using Ninja
1.9+. Ninja 1.9 enabled high-resolution time stamps, but pax doesn't
correctly set high-resolution timestamps on its output.
See https://github.com/nico/hack/blob/master/notes/copydir.md for a
detailed writeup of problem and alternatives.
For full-debug-info (is_debug=true / symbol_level=2 builds), this makes
linking 15% slower, but gdb startup 1500% faster (for lld: link time
3.9s->4.4s, gdb load time >30s->2s).
For link time, I ran
bench.py -o {noindex,index}.txt \
sh -c 'rm out/gn/bin/lld && ninja -C out/gn lld'
and then `ministat noindex.txt index.txt`:
```
x noindex.txt
+ index.txt
N Min Max Median Avg Stddev
x 5 3.784461 4.0200169 3.8452811 3.8754988 0.089902595
+ 5 4.32496 4.6058481 4.3361208 4.4141198 0.12288267
Difference at 95.0% confidence
0.538621 +/- 0.15702
13.8981% +/- 4.05161%
(Student's t, pooled s = 0.107663)
```
For gdb load time I loaded the crash in PR48392 with
gdb -ex r --args ../out/gn/bin/ld64.lld.darwinnew @response.txt
and just stopped the time until the crash got displayed with a stopwatch
a few times. So the speedup there is less precise, but it's so
pronounced that that's ok (loads ~instantly with the patch, takes a very
long time without it).
Only doing this for LLD because I haven't tried it with other linkers.
Differential Revision: https://reviews.llvm.org/D92844
is_debug by default makes symbol_level = 2 and !is_debug means by
default symbol_level = 0.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92958
llvm-config output with the gn build is just good enough to make
tests pass, but llvm-config wants all .a files it knows about to
actually exist. So let it know about fewer .a files that don't
exist if not all targets are enabled.
It's built with just-built clang, like all other compiler-rt parts
in the GN build.
This requires adding some cross build support to the mac toolchain.
Also add explicit mmacosx-version-min and miphoneos-version-min
flags to the build.
ios.a is only built with the arm64 slice, iossim.a only with the
x86_64 slice for now. (The latter should maybe become host_cpu
when Arm Macs become a common iOS development platform.)
With this, it's possible to build chromium/iOS with a GN-built LLVM.
Differential Revision: https://reviews.llvm.org/D89260
As of GN 3028c6a426a4, the hack that transformed "libs" ending in
".framework" from -l arguments to -framework arguments has been removed.
Instead, "frameworks" must be used, and the toolchain must provide
support.
Differential Revision: https://reviews.llvm.org/D84219
sync_source_lists_from_cmake now also looks for source files in
`sources += [ "foo.cc" ]` lines, which allows us to remove most
`# Make `gn format` not collapse this` comments.
(sync_source_lists_from_cmake doesn't look for `foo_headers += [...]`
still, so the comment is still needed in two places for that.)
No intentional behavior change.
This fixes the build of compiler-rt on macOS when _not_ using
clang_base_path in args.gn: Xcode clang knows where to find the
SDK, but regular clang doesn't and needs a -isysroot parameter.
We correctly add that parameter when clang_base_path is set,
but else we omit it. If clang_base_path was not set, we also
didn't add the flag for stage2_unix_toolchain() when we build
compiler-rt with just-built clang.
Make stage2_unix_toolchain() use clang_base_path instead of setting
cc / cxx. It's less code, and it gets things like this right.
Summary: Refactor the current global header iteration to be callback-based, and add a feature that reports the size of the global variable during reporting. This allows binaries without symbols to still report the size of the global variable, which is always available in the HWASan globals PT_NOTE metadata.
Reviewers: eugenis, pcc
Reviewed By: pcc
Subscribers: mgorny, llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D80599
Summary:
Fixes up two small issues with the gn build.
1 - Ensures that the correct ldflag `-pthread` is provided, not just linking the library.
2 - Ensures that libraries are linked in the same group as the dependencies. This fixes a problem where system libraries (libc) are involved in a link-order dependency that's not being fulfilled.
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80591
lld's symbol resolution algorithm makes it not depend on
the order of object files and libraries, but ld.bfd and
gold require listing dependencies later on the link line.
Put {{libs}} after {{inputs}} so that e.g. -lpthreads
appears after the object files, not before it.
Differential Revision: https://reviews.llvm.org/D81035
- only complain about duplicate 'sources' lines if they contain
more than 1 elements each (before, 0 and 1 element lists were
counted too). In practice, this only has an effect for
clang/lib/Headers/BUILD.gn
- make the '# NOSORT' diag actually work. This too only affects
clang/lib/Headers/BUILD.gn.
In aggregate, changes to clang/lib/Headers/BUILD.gn still can't
be auto-merged, but for a slighly better reason.
\<foo\> is more correct, but since we use shell=True on Windows,
the < and > get interpreted as redirection operators.
Rather than adding cmd escaping, just use \bfoo\b, which is Good
Enough Often Enough.
This is like -fdata-sections, and it's not part of /O2 by default for some reason.
In the cmake build, reduces the size of clang.exe from 70,358,016 bytes to 69,982,720 bytes.
clang-format.exe goes from 3,703,296 bytes to 3,331,072 bytes.
Differential Revision: https://reviews.llvm.org/D74573
Before, the script used `git log -SFoo.cpp` to find a commit where
the number of occurrences of "Foo.cpp" changed -- but since
a patch with
+ LLVMFoo.cpp
- Foo.cpp
contains the same number of instances of "Foo.cpp", the script
incorrectly skipped this type of rename.
As fix, look for '\bFoo\.cpp\b' instead and pass --pickaxe-regex
so that we can grep for word boundaries.
To test, check out 7531a5039f (which renamed in llvm/lib/IR
RemarkStreamer.cpp to LLVMRemarkStreamer.cpp) and look at the output of
the script. Before this change, it correctly assigned the addition
of LLVMRemarkStreamer.cpp to 7531a5039f but incorrectly assigned
the removal of RemarkStreamer.cpp to b8a847c. With this, it
correctly assigns both to 7531a5039f.
Previously, the gn build would create VCSRevision.h / VCSVersion.h
files with some LLD_REVISION / LLVM_REVISION / CLANG_REVISION but
by default wouldn't add a dependency on .git/logs/HEAD so that
the step doesn't rerun after every branch switch or every pull.
That's bad for deterministic builds, and having --version print
some arbitrarily old revision isn't great either.
Instead, move to the model that the cmake build (now) uses fairly
consistently: If llvm_append_vc_rev is set, include the revision,
else don't.
Since the GN build is focused on developers, set llvm_append_vc_rev
to false instead of true by default (different from the cmake build),
so that things don't rebuild after every branch switch and every
pull.
While here, also remove some pre-monorepo code.
Differential Revision: https://reviews.llvm.org/D72859
Nico Weber