8.0.1 final release r366581. The only functional change is a fix for a
mismerge of upstream r360816, which properly restores the r2 register
when unwinding on PowerPC64 (See https://reviews.freebsd.org/D20337).
Relnotes: yes
PR: 236062
MFC after: 3 days
X-MFC-With: r349004
libunwind and openmp to the upstream release_80 branch r364487
(effectively, 8.0.1 rc3). The 8.0.1 release will most likely
have no further changes.
MFC after: 1 week
X-MFC-With: r349004
libunwind and openmp to the upstream release_80 branch r363030
(effectively, 8.0.1 rc2). The 8.0.1 release should follow this within a
week or so.
MFC after: 2 weeks
[ELF] Support --{,no-}allow-shlib-undefined
Summary:
In ld.bfd/gold, --no-allow-shlib-undefined is the default when
linking an executable. This patch implements a check to error on
undefined symbols in a shared object, if all of its DT_NEEDED entries
are seen.
Our approach resembles the one used in gold, achieves a good balance
to be useful but not too smart (ld.bfd traces all DSOs and emulates
the behavior of a dynamic linker to catch more cases).
The error is issued based on the symbol table, different from
undefined reference errors issued for relocations. It is most
effective when there are DSOs that were not linked with -z defs (e.g.
when static sanitizers runtime is used).
gold has a comment that some system libraries on GNU/Linux may have
spurious undefined references and thus system libraries should be
excluded (https://sourceware.org/bugzilla/show_bug.cgi?id=6811). The
story may have changed now but we make --allow-shlib-undefined the
default for now. Its interaction with -shared can be discussed in the
future.
Reviewers: ruiu, grimar, pcc, espindola
Reviewed By: ruiu
Subscribers: joerg, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D57385
Pull in r352943 from upstream lld trunk (by Fangrui Song):
[ELF] Default to --no-allow-shlib-undefined for executables
Summary:
This follows the ld.bfd/gold behavior.
The error check is useful as it captures a common type of ld.so
undefined symbol errors as link-time errors:
// a.cc => a.so (not linked with -z defs)
void f(); // f is undefined
void g() { f(); }
// b.cc => executable with a DT_NEEDED entry on a.so
void g();
int main() { g(); }
// ld.so errors when g() is executed (lazy binding) or when the program is started (-z now)
// symbol lookup error: ... undefined symbol: f
Reviewers: ruiu, grimar, pcc, espindola
Reviewed By: ruiu
Subscribers: llvm-commits, emaste, arichardson
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57569
Together, these add support for --no-allow-shlib-undefined, and make it
the default for executables, so they will fail to link if any symbols
from needed shared libraries are undefined.
Reported by: jbeich
PR: 236062, 236141
MFC after: 1 month
X-MFC-With: r344779
7.0.1 release r349250. There were no functional changes since the 7.0.1
rc3 import.
PR: 230240, 230355
Relnotes: yes
MFC after: 2 months
X-MFC-With: r341825
ELF spec says that for SHT_REL and SHT_RELA sh_link should reference the
associated string table and sh_info should reference the "section to
which the relocation applies." ELF Tool Chain's elfcopy / strip use
this (in part) to control whether or not the relocation entry is copied
to the output.
LLVM PR 37538 https://bugs.llvm.org/show_bug.cgi?id=37538
Approved by: re (kib)
Obtained from: llvm r344226 (backported for 6.0)
BPF (eBPF) is an independent instruction set architecture which is
introduced in Linux a few years ago. Originally, eBPF execute
environment was only inside Linux kernel. However, recent years there
are some user space implementation (https://github.com/iovisor/ubpf,
https://doc.dpdk.org/guides/prog_guide/bpf_lib.html) and kernel space
implementation for FreeBSD is going on
(https://github.com/YutaroHayakawa/generic-ebpf).
The BPF target support can be enabled using WITH_LLVM_TARGET_BPF, as it
is not built by default.
Submitted by: Yutaro Hayakawa <yhayakawa3720@gmail.com>
Reviewed by: dim, bdrewery
Differential Revision: https://reviews.freebsd.org/D16033
All supported FreeBSD build host versions have backtrace.h, so we can
just eliminate that test. For futimes() we can test the compiler's
built-in __FreeBSD__ major version rather than relying on including
osreldate.h. This should reduce the frequency with which Clang gets
rebuilt when building world.
Reviewed by: dim
Sponsored by: The FreeBSD Foundation
This makes it possible, through src.conf(5) settings, to select which
LLVM targets you want to build during buildworld. The current list is:
* (WITH|WITHOUT)_LLVM_TARGET_AARCH64
* (WITH|WITHOUT)_LLVM_TARGET_ARM
* (WITH|WITHOUT)_LLVM_TARGET_MIPS
* (WITH|WITHOUT)_LLVM_TARGET_POWERPC
* (WITH|WITHOUT)_LLVM_TARGET_SPARC
* (WITH|WITHOUT)_LLVM_TARGET_X86
To not influence anything right now, all of these are on by default, in
situations where clang is enabled.
Selectively turning a few targets off manually should work. Turning on
only one target should work too, even if that target does not correspond
to the build architecture. (In that case, LLVM_NATIVE_ARCH will not be
defined, and you can only use the resulting clang executable for
cross-compiling.)
I performed a few measurements on one of the FreeBSD.org reference
machines, building clang from scratch, with all targets enabled, and
with only the x86 target enabled. The latter was ~12% faster in real
time (on a 32-core box), and ~14% faster in user time. For a full
buildworld the difference will probably be less pronounced, though.
Reviewed by: bdrewery
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D11077
A non-alloc note section should not have a PT_NOTE program header.
Found while linking ghc (Haskell compiler) with lld on FreeBSD. Haskell
emits a .debug-ghc-link-info note section (as the name suggests, it
contains link info) as a SHT_NOTE section without SHF_ALLOC set.
For this case ld.bfd does not emit a PT_NOTE segment for
.debug-ghc-link-info. lld previously emitted a PT_NOTE with p_vaddr = 0
and FreeBSD's rtld segfaulted when trying to parse a note at address 0.
LLVM PR: https://llvm.org/pr37361
LLVM review: https://reviews.llvm.org/D46623
PR: 226872
Reviewed by: dim
Sponsored by: The FreeBSD Foundation
This will faciliate a WITH_SYSTEM_LINKER option.
Reviewed by: dim
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D15110
