Commit Graph

442 Commits

Author SHA1 Message Date
Amilendra Kodithuwakku 5636402bc0 [libcxx] Fix exception raised during downstream bare-metal libunwind tests
Fix for the following exception.

AttributeError: 'TestingConfig' object has no attribute 'target_triple'

Related revision: https://reviews.llvm.org/D102012

'TestingConfig' object has no attribute 'target_triple'

Reviewed By: #libunwind, miyuki, danielkiss, mstorsjo

Differential Revision: https://reviews.llvm.org/D103140
2021-06-16 13:35:36 +01:00
Saleem Abdulrasool e03be2efe5 unwind: allow building with GCC
This was regressed in adf1561d6c.  Since gcc does not support
`__has_feature`, this adjusts the build to use the
`__SANITIZE_ADDRESS__` macro which GCC defines to identify if ASAN is
enabled (similar to `__has_feature`).  This allows building libunwind
with gcc again.

Patch by Daniel Levin!

Reviewed By: compnerd

Differential Revision: https://reviews.llvm.org/D104176
2021-06-13 14:44:54 -07:00
Louis Dionne 875ff8e059 [libc++] Enable tests for the experimental library by default
This matches the fact that we build the experimental library by default.
Otherwise, by default we'd be building the library but not testing it,
which is inconsistent.

Differential Revision: https://reviews.llvm.org/D102109
2021-06-02 18:39:27 -04:00
Nico Weber 2fc05fdc15 [libunwind] fix -Wc++98-compat-extra-semi without _LIBUNWIND_HIDE_SYMBOLS 2021-05-31 08:54:53 -04:00
Shoaib Meenai adf1561d6c [libunwind] Inform ASan that resumption is noreturn
If you're building libunwind instrumented with ASan, `_Unwind_RaiseException`
will poison the stack and then transfer control in a manner which isn't
understood by ASan, so the stack will remain poisoned. This can cause
false positives, e.g. if you call an uninstrumented function (so it
doesn't re-poison the stack) after catching an exception. Add a call to
`__asan_handle_no_return` inside `__unw_resume` to get ASan to unpoison
the stack and avoid this.

`__unw_resume` seems like the appropriate place to make this call, since
it's used for resumption by all unwind implementations except SJLJ. SJLJ
uses `__builtin_longjmp` to handle resumption, which is already
recognized as noreturn (and therefore ASan adds the `__asan_handle_no_return`
call itself), so it doesn't need any special handling.

PR32434 is somewhat similar (in particular needing a component built
without ASan to trigger the bug), and rG781ef03e1012, the fix for that
bug, adds an interceptor for `_Unwind_RaiseException`. This interceptor
won't always be triggered though, e.g. if you statically link the
unwinder into libc++abi in a way that prevents interposing the unwinder
functions (e.g. marking the symbols as hidden, using `--exclude-libs`,
or using `-Bsymbolic`). rG53335d6d86d5 makes `__cxa_throw` call
`__asan_handle_no_return` explicitly, to similarly avoid relying on
interception.

Reviewed By: #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D103002
2021-05-26 09:31:39 -07:00
Louis Dionne 74d096e558 [libc++] Move handling of the target triple to the DSL
This fixes a long standing issue where the triple is not always set
consistently in all configurations. This change also moves the
back-deployment Lit features to using the proper target triple
instead of using something ad-hoc.

This will be necessary for using from scratch Lit configuration files
in both normal testing and back-deployment testing.

Differential Revision: https://reviews.llvm.org/D102012
2021-05-08 11:10:53 -04:00
Xing Xue 8408d3f2d8 [libunwind] NFC: Use macros to accommodate differences in representation of PowerPC assemblers
Summary:
This NFC patch replaces the representation of registers and the left shift operator in the PowerPC assembly code to allow it to be consumed by the GNU flavored assembler and the AIX assembler.

* Registers - change the representation of PowperPC registers from %rn, %fn, %vsn, and %vrn to the register number alone, e.g., n. The GNU flavored assembler and the AIX assembler are able to determine the register kind based on the context of the instruction in which the register is used.

* Left shift operator - use macro PPC_LEFT_SHIFT to represent the left shift operator. The left shift operator in the AIX assembly language is < instead of <<

Reviewed by: sfertile, MaskRay, compnerd

Differential Revision: https://reviews.llvm.org/D101179
2021-05-06 14:33:38 -04:00
Petr Hosek f749550cfe [libcxx] Stop using use c++ subdirectory for libc++ library
The new layout more closely matches the layout used by other compilers.
This is only used when LLVM_ENABLE_PER_TARGET_RUNTIME_DIR is enabled.

Differential Revision: https://reviews.llvm.org/D100869
2021-04-21 15:39:03 -07:00
Petr Hosek 96d8c6b571 [CMake] Remove {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_PREFIX
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.

Differential Revision: https://reviews.llvm.org/D99697
2021-04-01 10:13:07 -07:00
Louis Dionne c06a8f9caa [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

Differential Revision: https://reviews.llvm.org/D97572
2021-03-30 14:06:11 -07:00
Martin Storsjö 39ad160468 [libunwind] Install the DLL when doing "ninja install"
This matches how install(... RUNTIME) is used in e.g. libcxx.

Differential Revision: https://reviews.llvm.org/D98020
2021-03-07 10:36:22 +02:00
Kamlesh Kumar 5c3fc5093a [libunwind] [risc-v] This patch is for fixing
immediate build failure when Cross Unwinding enabled.
Follow up patch will cleanup some Macros handling.

Differential Revision: https://reviews.llvm.org/D97762
2021-03-03 04:32:47 +05:30
Kamlesh Kumar b17d46430f [libunwind] This adds support in libunwind for rv32 hard float
and soft-float for both rv32 and rv64.

Differential Revision: https://reviews.llvm.org/D80690
2021-03-02 06:58:24 +05:30
Louis Dionne 60ba1fefab [libc++/abi] Allow running back-deployment testing against libc++abi
Before this patch, we could only link against the back-deployment libc++abi
dylib. This patch allows linking against the just-built libc++abi, but
running against the back-deployment one -- just like we do for libc++.

Also, add XFAIL markup to flag expected errors.

Differential Revision: https://reviews.llvm.org/D91069
2021-03-01 12:13:03 -05:00
Ryan Prichard 729899f7b6 [libunwind] unw_* alias fixes for ELF and Mach-O
Rename the CMake option, LIBUNWIND_HERMETIC_STATIC_LIBRARY, to
LIBUNWIND_HIDE_SYMBOLS. Rename the C macro define,
_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS, to _LIBUNWIND_HIDE_SYMBOLS,
because now the macro adds a .hidden directive rather than merely
suppress visibility annotations.

For ELF, when LIBUNWIND_HIDE_SYMBOLS is enabled, mark unw_getcontext as
hidden. This symbol is the only one defined using src/assembly.h's
WEAK_ALIAS macro. Other unw_* weak aliases are defined in C++ and are
already hidden.

Mach-O doesn't support weak aliases, so remove .weak_reference and
weak_import. When LIBUNWIND_HIDE_SYMBOLS is enabled, output
.private_extern for the unw_* aliases.

In assembly.h, add missing SYMBOL_NAME macro invocations, which are
used to prefix symbol names with '_' on some targets.

Fixes PR46709.

Reviewed By: #libunwind, phosek, compnerd, steven_wu

Differential Revision: https://reviews.llvm.org/D93003
2021-02-22 16:54:05 -08:00
Marco Vanotti 78eabcaa48 [libunwind] Add support for PC reg column in arm64
This change adds support for the dwarf PC register column in arm64, allowing
CFI directives to make use of it.

As of the last revision of the DWARF for ARM 64-bit architecture[0], the pc
register has been added as a valir register, with number 32.

This allows libunwinder to restore both pc and lr, which is useful
for stack switches and signal contexts.

[0]:
f52e1ad3f8/aadwarf64/aadwarf64.rst

Reviewed By: phosek, #libunwind

Differential Revision: https://reviews.llvm.org/D96901
2021-02-17 17:42:19 -08:00
Peter Collingbourne cddc53ef08 libunwind: Don't attempt to authenticate a null return address.
Null return addresses can appear at the bottom of the stack (i.e. the
frame corresponding to the entry point). Authenticating these addresses
will set the error code in the address, which will lead to a segfault
in the sigreturn trampoline detection code. Fix this problem by not
authenticating null addresses.

Differential Revision: https://reviews.llvm.org/D96560
2021-02-16 11:18:02 -08:00
Zbigniew Sarbinowski 5f9be2c3e3 [SystemZ][ZOS] Prefer -nostdlib++ as opposed to -nodefaultlibs when building c++ libraries
Let's use -nostdlib++ rather than -nodefaultlibs when building libc++/libc++abi/libunwind libraries. The default is -nostdlib++ if supported by a build compiler like it is the case with clang, otherwise -nodefaultlibs is used as before.

This change is needed to avoid additional changes at the link step and not to increase the maintenance costs. If clang with -nodefaultlibs is used all the libraries which are removed but required would have to be manually added in. This set of libraries are unique and will send out.

The propose change will allow to make the link step simple for other platforms as well.

Reviewed By: #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D95875
2021-02-16 18:42:14 +00:00
Kristina Bessonova f042fd46b5 [libunwind][cmake] Add an option to enable/disable tests
Reviewed By: ldionne, compnerd

Differential Revision: https://reviews.llvm.org/D96342
2021-02-13 12:49:48 +02:00
xgupta 77fecc0795 [NFC][libunbind] Fix Sphinx error during CMake invocation
An error has occurred when I build libunwind with -DLLVM_BUILD_DOCS=ON.

Reviewed By: #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D96107
2021-02-11 06:52:24 +05:30
xgupta 94fac81fcc [Branch-Rename] Fix some links
According to the [[ https://foundation.llvm.org/docs/branch-rename/ | status of branch rename ]], the master branch of the LLVM repository is removed on 28 Jan 2021.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D95766
2021-02-01 16:43:21 +05:30
Tom Stellard 5369517d20 Bump the trunk major version to 13
and clear the release notes.
2021-01-26 19:37:55 -08:00
Raul Tambre 480643a95c [CMake] Remove dead code setting policies to NEW
cmake_minimum_required(VERSION) calls cmake_policy(VERSION),
which sets all policies up to VERSION to NEW.
LLVM started requiring CMake 3.13 last year, so we can remove
a bunch of code setting policies prior to 3.13 to NEW as it
no longer has any effect.

Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D94374
2021-01-19 17:19:36 +02:00
Kazushi (Jam) Marukawa 3cbd476c54 [VE] Support VE in libunwind
Modify libunwind to support SjLj exception handling routines for VE.
In order to do that, we need to implement not only SjLj exception
handling routines but also a Registers_ve class.  This implementation
of Registers_ve is incomplete.  We will work on it later when we need
backtrace in libunwind.

Reviewed By: #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D94591
2021-01-17 15:35:02 +09:00
Ryan Prichard c82deed676 [libunwind] Unwind through aarch64/Linux sigreturn frame
An AArch64 sigreturn trampoline frame can't currently be described
in a DWARF .eh_frame section, because the AArch64 DWARF spec currently
doesn't define a constant for the PC register. (PC and LR may need to
be restored to different values.)

Instead, use the same technique as libgcc or github.com/libunwind and
detect the sigreturn frame by looking for the sigreturn instructions:

    mov x8, #0x8b
    svc #0x0

If a sigreturn frame is detected, libunwind restores all the GPRs by
assuming that sp points at an rt_sigframe Linux kernel struct. This
behavior is a fallback mode that is only used if there is no ordinary
unwind info for sigreturn.

If libunwind can't find unwind info for a PC, it assumes that the PC is
readable, and would crash if it isn't. This could happen if:
 - The PC points at a function compiled without unwind info, and which
   is part of an execute-only mapping (e.g. using -Wl,--execute-only).
 - The PC is invalid and happens to point to unreadable or unmapped
   memory.

In the tests, ignore a failed dladdr call so that the tests can run on
user-mode qemu for AArch64, which uses a stack-allocated trampoline
instead of a vDSO.

Reviewed By: danielkiss, compnerd, #libunwind

Differential Revision: https://reviews.llvm.org/D90898
2021-01-13 16:38:36 -08:00
Brandon Bergren bb13411614 [libunwind] Multiple preprocessor fixes on PowerPC*
* Remove misnamed `PPC64_HAS_VMX` in preference of directly checking `defined(__VSX__)`.

libunwind was using "VMX" to mean "VSX". "VMX" is just another name for Altivec, while "VSX" is the vector-scalar extensions first used in POWER7. Exposing a "PPC64_HAS_VMX" define was misleading and incorrect.

* Add `defined(__ALTIVEC__)` guards around vector register operations to fix non-altivec CPUS such as the e5500.

When compiling for certain Book-E processors such as the e5500, we want to skip vector save/restore, as the Altivec registers are illegal on non-Altivec implementations.

* Add `!defined(__NO_FPRS__)` guards around traditional floating-point save/restore.

When compiling for powerpcspe, we cannot access floating point registers, as there aren't any. (The SPE on e500v2 is a 64-bit extension of the GPRs, and it doesn't have the normal floating-point registers at all.)
This fixes building for powerpcspe, although no actual handling for SPE save/restore is written yet.

Reviewed By: MaskRay, #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D91906
2020-11-23 19:07:21 -08:00
Fangrui Song 3324fd8a7b [libunwind] Delete unused handlerNotFound in unwind_phase1 2020-11-21 12:38:00 -08:00
Daniel Kiss e7b8d3776f [libunwind] LIBUNWIND_REMEMBER_HEAP_ALLOC to cmake.
Missed it originally in https://reviews.llvm.org/D85005.

Reviewed By: gargaroff

Differential Revision: https://reviews.llvm.org/D91182
2020-11-11 11:21:17 +01:00
Louis Dionne 8d51969bd4 [runtimes] Avoid overwriting the rpath unconditionally
When building the runtimes, it's very important not to add rpaths unless
the user explicitly asks for them (the standard way being CMAKE_INSTALL_RPATH),
or to change the install name dir unless the user requests it (via
CMAKE_INSTALL_NAME_DIR).

llvm_setup_rpath() would override the install_name_dir of the runtimes
even if CMAKE_INSTALL_NAME_DIR was specified to something, which is wrong
and in fact even "dangerous" for the runtimes.

This issue was discovered when trying to build libc++ and libc++abi as
system libraries for Apple, where we set the install name dir to /usr/lib
explicitly. llvm_setup_rpath() would cause libc++ to have the wrong install
name dir, and for basically everything on the system to fail to load.
This was discovered just now because we previously used something closer
to a standalone build, where llvm_setup_rpath() wouldn't exist, and hence
not be used.

This is a revert of the following commits:

  libunwind: 3a667b9bd8
  libc++abi: 4877063e19
  libc++: 88434fe05f

Those added llvm_setup_rpath() for consistency, so it seems reasonable
to revert.

Differential Revision: https://reviews.llvm.org/D91099
2020-11-09 16:56:03 -05:00
Fangrui Song 2c481f128c [libunwind] Delete unused codeOffsetAtStackDecrement/registersInOtherRegisters/sameValueUsed
ld64 uses them to create compact unwind from DWARF call frame information.
When the code was ported to libunwind, the variables were not deleted.

Reviewed By: #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D91039
2020-11-09 10:19:12 -08:00
Louis Dionne c1887e3f15 Revert "Allow running back-deployment testing against libc++abi"
This reverts commit 4d79ef814a, which broke a few build bots.
I'm reverting until I have time to investigate.
2020-11-06 17:26:42 -05:00
Louis Dionne 4d79ef814a Allow running back-deployment testing against libc++abi
Summary:
Before this patch, we could only link against the back-deployment libc++abi
dylib. This patch allows linking against the just-built libc++abi, but
running against the back-deployment one -- just like we do for libc++.

Also, add XFAIL markup to flag expected errors.
2020-11-06 08:12:46 -05:00
Daniel Kiss 1d7786d45f [libunwind] Support DW_CFA_remember/restore_state without heap allocation.
This patch just reorganises the code to make possible to use alloca
instead of malloc. This makes possible to use `.cfi_remember_state`/`.cfi_restore_state` on
platforms without heap allocation.
Also it will be safe to backtrace/unwind faults related to the allocator behind malloc.
`_LIBUNWIND_REMEMBER_HEAP_ALLOC ` option reenables the heap usage for `.cfi_remember_state`/`.cfi_restore_state`.
Define _LIBUNWIND_REMEMBER_STACK_ALLOC to force stack allocation.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D85005
2020-10-30 17:45:20 +01:00
Daniel Kiss 05598e3d30 [libunwind] Fix linker flag handling in the tests.
--export-dynamic is not always available on all targets.
-funwind-tables was a duplicate in the lit.site.cfg.in.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D90202
2020-10-29 14:02:44 +01:00
Martin Storsjö df6d2e8ab1 [libunwind] Add -Wno-dll-attribute-on-redeclaration when building for windows
It's not worth trying to fix these warnings within libunwind, instead
silence them.

Differential Revision: https://reviews.llvm.org/D90075
2020-10-26 23:23:01 +02:00
Louis Dionne 48e4b0fd3a [runtimes] Revert the libc++ __config_site change
This is a massive revert of the following commits (from most revent to oldest):

	2b9b7b5775.
	529ac33197
	28270234f1
	69c2087283
	b5aa67446e
	5d796645d6

After checking-in the __config_site change, a lot of things started breaking
due to widespread reliance on various aspects of libc++'s build, notably the
fact that we can include the headers from the source tree, but also reliance
on various "internal" CMake variables used by the runtimes build and compiler-rt.

These were unintended consequences of the change, and after two days, we
still haven't restored all the bots to being green. Instead, now that I
understand what specific areas this will blow up in, I should be able to
chop up the patch into smaller ones that are easier to digest.

See https://reviews.llvm.org/D89041 for more details on this adventure.
2020-10-23 09:41:48 -04:00
Louis Dionne 5d796645d6 [take 2] [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

This commit was originally applied in 1e46d1aa3 and reverted in eb60c487
because it broke the libc++abi and libunwind test suites. This has now
been fixed.

Differential Revision: https://reviews.llvm.org/D89041
2020-10-21 10:40:33 -04:00
Dominik Montada 8c03fdf34a [libcxxabi,libunwind] support running tests in standalone mode
Remove check for standalone and shared library mode in libcxxabi to
allow including tests in said mode. This check prevented running the
tests in standalone mode with static libraries, which is the case for
baremetal targets.

Fix check-unwind target trying to use a non-existent llvm-lit executable
in standalone mode. Copy the HandleOutOfTreeLLVM logic from libcxxabi to
libunwind in order to make the tests work in standalone mode.

Reviewed By: ldionne, #libc_abi, #libc

Differential Revision: https://reviews.llvm.org/D86540
2020-10-14 09:10:20 +02:00
Raphael Isemann 6b7a49bb43 Fix all the CMake code that can only handle -stdlib= but not --stdlib=
There are several places in LLVM's CMake setup that try to remove the
`stdlib=...` flag from the CMake flags. All this code however only considered
the `-stdlib=` variant of the flag but not the alternative spelling with a
double dash. This causes that when one adds `--stdlib=...` to the user-provided
CMake flags that this gets transformed into just `-` which ends up causing the
build system to think it should read the source from stdin (which then lead to
very confusing build errors).

This just adds the alternative spelling before the`-stdlib=` variant in all
these places

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D87133
2020-10-13 16:05:21 +02:00
Martin Storsjö fc5e68fab9 [libunwind] [SEH] Don't interact with foreign exceptions
This unfortunately means that we don't execute C++ destructors when
unwinding past such frames for a different SEH unwind purpose (e.g.
as part of setjmp/longjmp), but that case isn't handled properly at
the moment (the original unwind intent is lost and we end up with an
unhandled exception). This patch makes sure the foreign unwind terminates
as intended.

After executing a handler, _Unwind_Resume doesn't have access to
the target frame parameter of the original foreign unwind. We also
currently blindly set ExceptionCode to STATUS_GCC_THROW - we could
set that correctly by storing the original code in _GCC_specific_handler,
but we don't have access to the original target frame value.

This also matches what libgcc's SEH unwinding code does in this case.

Differential Revision: https://reviews.llvm.org/D89231
2020-10-12 23:28:22 +03:00
Louis Dionne 504bc07d1a [runtimes] Use int main(int, char**) consistently in tests
This is needed when running the tests in Freestanding mode, where main()
isn't treated specially. In Freestanding, main() doesn't get mangled as
extern "C", so whatever runtime we're using fails to find the entry point.

One way to solve this problem is to define a symbol alias from __Z4mainiPPc
to _main, however this requires all definitions of main() to have the same
mangling. Hence this commit.
2020-10-08 14:28:13 -04:00
Daniel Kiss f34ae1b9de [AArch64] Add v8.5 Branch Target Identification support.
The .note.gnu.property must be in the assembly file to indicate the
support for BTI otherwise BTI will be disabled for the whole library.
__unw_getcontext and libunwind::Registers_arm64::jumpto() may be called
indirectly therefore they should start with a landing pad.

Reviewed By: tamas.petz, #libunwind, compnerd

Differential Revision: https://reviews.llvm.org/D77786
2020-09-29 15:51:01 +02:00
Ryan Prichard 881aba7071 [libunwind] Optimize dl_iterate_phdr's findUnwindSectionsByPhdr
Currently, findUnwindSectionsByPhdr is slightly micro-optimized for the
case where the first callback has the target address, and is otherwise
very inefficient -- it decodes .eh_frame_hdr even when no PT_LOAD
matches the PC. (If the FrameHeaderCache is enabled, then the
micro-optimization only helps the first time unwind info is looked up.)

Instead, it makes more sense to optimize for the case where the
callback *doesn't* find the target address, so search for a PT_LOAD
segment first, and only look for the unwind info section if a matching
PT_LOAD is found.

This change helps on an Android benchmark with 100 shared objects,
where the DSO at the end of the dl_iterate_phdr list throws 10000
exceptions. Assuming the frame cache is disabled, this change cuts
about 30-40% off the benchmark's runtime.

Reviewed By: compnerd, saugustine, #libunwind

Differential Revision: https://reviews.llvm.org/D87881
2020-09-23 15:40:39 -07:00
Ryan Prichard b16d6653c0 [libunwind] Combine dl_iterate_phdr codepaths for DWARF and EHABI
dl_iterate_phdr is used to search for unwind info provided by either
PT_GNU_EH_FRAME or PT_ARM_EXIDX. Most of the code between the two is
the same, so combine them, and factor out what's different into
checkForUnwindInfoSegment.

Details:
 - The FrameHeaderCache can now be enabled for ARM EHABI.
 - findUnwindSectionsByPhdr now finds the last PT_ARM_EXIDX rather than
   the first. There should only be one segment.
 - The dso_base and text_segment_length fields of UnwindInfoSections
   are now needed for dl_iterate_phdr when using EHABI, to hold the
   low and high PC values for a cache entry.

Reviewed By: compnerd, danielkiss, #libunwind, saugustine

Differential Revision: https://reviews.llvm.org/D87880
2020-09-23 15:40:39 -07:00
Dave Lee b36bdfe5ca [cmake] Centralize LLVM_ENABLE_WARNINGS option
Configure default value of `LLVM_ENABLE_WARNINGS` in `HandleLLVMOptions.cmake`.

`LLVM_ENABLE_WARNINGS` is documented as ON by default, but `HandleLLVMOptions` assumes the default has been set somewhere else. If it has not been explicitly set, then `HandleLLVMOptions` implicitly uses OFF as a default.

This removes the various `option()` declarations in favor of a single declaration in `HandleLLVMOptions`. This will prevent the unwanted use of `-w` that is mentioned in a couple of the comments.

Reviewed By: DavidTruby, #libunwind, JDevlieghere, compnerd

Differential Revision: https://reviews.llvm.org/D87243
2020-09-21 10:23:17 -07:00
Daniel Kiss 22b615a965 [libunwind] Support for leaf function unwinding.
Unwinding leaf function is useful in cases when the backtrace finds a
leaf function for example when it caused a signal.
This patch also add the support for the DW_CFA_undefined because it marks
the end of the frames.

Ryan Prichard provided code for the tests.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D83573

Reland with limit the test to the x86_64-linux target.
2020-09-18 15:09:42 +02:00
Daniel Kiss 5831adb8c3 Revert "[libunwind] Support for leaf function unwinding."
This reverts commit 23bef7ee99.
2020-09-18 11:37:54 +02:00
Ryan Prichard fb1abe0063 [libunwind][DWARF] Fix end of .eh_frame calculation
* When .eh_frame is located using .eh_frame_hdr (PT_GNU_EH_FRAME), the
   start of .eh_frame is known, but not the size. In this case, the
   unwinder must rely on a terminator present at the end of .eh_frame.
   Set dwarf_section_length to UINTPTR_MAX to indicate this.

 * Add a new field, text_segment_length, that the FrameHeaderCache uses
   to track the size of the PT_LOAD segment indicated by dso_base.

 * Compute ehSectionEnd by adding sectionLength to ehSectionStart,
   never to fdeHint.

Fixes PR46829.

Differential Revision: https://reviews.llvm.org/D87750
2020-09-16 19:00:57 -07:00
Daniel Kiss 23bef7ee99 [libunwind] Support for leaf function unwinding.
Unwinding leaf function is useful in cases when the backtrace finds a
leaf function for example when it caused a signal.
This patch also add the support for the DW_CFA_undefined because it marks
the end of the frames.

Ryan Prichard provided code for the tests.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D83573
2020-09-16 23:53:36 +02:00
Louis Dionne ec46cfefe8 [libcxx] Simplify back-deployment testing
The needs of back-deployment testing currently require two different
ways of running the test suite: one based on the deployment target,
and one based on the target triple. Since the triple includes all the
information we need, it's better to have just one way of doing things.

Furthermore, `--param platform=XXX` is also supersedded by using the
target triple. Previously, this parameter would serve the purpose of
controling XFAILs for availability markup errors, however it is possible
to achieve the same thing by using with_system_cxx_lib only and using
.verify.cpp tests instead, as explained in the documentation changes.

The motivation for this change is twofold:
1. This part of the Lit config has always been really confusing and
   complicated, and it has been a source of bugs in the past. I have
   simplified it iteratively in the past, but the complexity is still
   there.
2. The deployment-target detection started failing in weird ways in
   recent Clangs, breaking our CI. Instead of band-aid patching the
   issue, I decided to remove the complexity altogether by using target
   triples even on Apple platforms.

A follow-up to this commit will bring the test suite in line with
the recommended way of handling availability markup tests.
2020-09-10 08:17:26 -04:00