Commit Graph

23 Commits

Author SHA1 Message Date
Shoaib Meenai cc259638cb [libcxx][libcxxabi][libunwind] Use libgcc on Android
Android doesn't have a libgcc_s and uses libgcc instead, so adjust the
build accordingly. This matches compiler-rt's build setup. libc++abi and
libunwind were already checking for libgcc but in a different context.
This change makes them search only for libgcc on Android now, but the
code to link against libgcc if it were present was already there.

Reviewed By: #libc, #libc_abi, #libunwind, rprichard, srhines

Differential Revision: https://reviews.llvm.org/D78787
2020-04-30 15:42:32 -07:00
Petr Hosek 547659ae56 [unwind] Don't link libpthread and libdl on Fuchsia
This is a follow up to D71135.
2019-12-17 17:21:43 -08:00
Sergej Jaskiewicz 57fc8ecdba Reland "Enable `-funwind-tables` flag when building libunwind"
Summary:
Relands https://reviews.llvm.org/D70815.

The original commit set `CMAKE_TRY_COMPILE_TARGET_TYPE` to
`STATIC_LIBRARY` globally in libunwind/CMakeLists.txt, which effectively
disabled the linking step in CMake checks.

This broke some builds (see 938c70b86c).

Here we set CMAKE_TRY_COMPILE_TARGET_TYPE to
STATIC_LIBRARY only when checking for presence of the `-funwind-tables`
flag, and then set it back to the original value so it doesn't affect
other checks.

Reviewers: mstorsjo, jfb

Subscribers: mgorny, christof, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D71117
2019-12-11 04:27:04 +03:00
Martin Storsjö 938c70b86c Revert "Enable `-funwind-tables` flag when building libunwind"
This reverts commit b3fdf33ba6.

This change broke building libunwind for Windows/MinGW, and broke
on aspect of the CMake tests in libunwind in general.

After set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY), CMake
skips the linking step in tests, but cmake/config-ix.cmake also
does a few checks for functions in libraries (looking for whether
-lc provides fopen and whether -ldl provides dladdr).

As CMake only tests building a static library, these tests
incorrectly succeed and CMake concludes "Looking for fopen in c -
found" and "Looking for dladdr in dl - found", while building
then fails at the end with errors about unable to find -lc and -ldl.
2019-12-04 09:29:15 +02:00
Sergej Jaskiewicz b3fdf33ba6 Enable `-funwind-tables` flag when building libunwind
Summary:
Or, rather, don't accidentally forget to pass it.

This is aimed to solve the problem discussed in [this thread](http://lists.llvm.org/pipermail/llvm-dev/2019-November/136890.html), and to fix [a year-old bug](https://bugs.llvm.org/show_bug.cgi?id=38468).

TL;DR: when building libunwind for ARM Linux, we **need** libunwind to be built with the `-funwind-tables` flag, because, well ARM EHABI needs unwind info produced by this flag. Without the flag all the procedures in libunwind are marked `.cantunwind`, which causes all sorts of bad things. From `_Unwind_Backtrace` not working, to C++ exceptions not being caught (which is the aforementioned bug is about).

Previously, this flag was not added because the CMake check `add_compile_flags_if_supported(-funwind-tables)` produced a false negative. Why? With this flag, the compiler generates calls to the `__aeabi_unwind_cpp_pr0` symbol, which is defined in libunwind itself and obviously is not available at configure time, before libunwind is built. This led to failure at link time during the CMake check. We handle this by disabling the linker for CMake checks in linbunwind.

Also, this patch introduces a lit feature `libunwind-arm-ehabi`, which is used to mark the `signal_frame.pass.cpp` test as unsupported (as was advised by @miyuki in D70397).

Reviewers: peter.smith, phosek, EricWF, compnerd, jroelofs, saugustine, miyuki, jfb

Subscribers: mgorny, kristof.beyls, christof, libcxx-commits, miyuki

Tags: #libc

Differential Revision: https://reviews.llvm.org/D70815
2019-12-04 00:52:19 +03:00
Petr Hosek 20da3bdb96 [libunwind] Refactor CMake flag checks to match libc++ and libc++abi
libunwind was using its own set of macros/functions for flag checking
which was similar but different from libc++ and libc++abi. This made
it difficult to replicate the same checks across projects, in fact
there were some checks that appear to have been copy & pasted from
another project and that were broken in the standalone libunwind build.
This change refactors flag checks to match libc++ and libc++abi using
a copy of HandleLibunwindFlags.cmake which is derived from the versions
used by the other projects. This also paves a road to deduplicating and
unifying HandleLibunwindFlags.cmake, HandleLibcxxabiFlags.cmake and
HandleLibcxxFlags.cmake post monorepo switch.

Differential Revision: https://reviews.llvm.org/D68855

llvm-svn: 374606
2019-10-11 22:22:29 +00:00
Petr Hosek f1ddf431b5 [runtimes] Use -Wunknown-pragmas for the pragma check
This is a follow up to r362055, we need -Wunknown-pragmas otherwise
the check is going to succeed it the pragma isn't supported.

llvm-svn: 362057
2019-05-30 05:38:06 +00:00
Petr Hosek 789b7f0828 [runtimes] Check if pragma comment(lib, ...) is supported first
This fixes the issue introduced by r362048 where we always use
pragma comment(lib, ...) for dependent libraries when the compiler
is Clang, but older Clang versions don't support this pragma so
we need to check first if it's supported before using it.

llvm-svn: 362055
2019-05-30 04:40:21 +00:00
Petr Hosek 12f4b86808 Revert "[CMake] Use __libc_start_main rather than fopen when checking for C library"
This reverts commit r352341: it broke the build on macOS which doesn't
seem to provide __libc_start_main in its C library.

llvm-svn: 352411
2019-01-28 19:26:41 +00:00
Petr Hosek b667153cf6 [CMake] Use __libc_start_main rather than fopen when checking for C library
The check_library_exists CMake uses a custom symbol definition. This
is a problem when checking for C library symbols because Clang
recognizes many of them as builtins, and returns the
-Wbuiltin-requires-header (or -Wincompatible-library-redeclaration)
error. When building with -Werror which is the default, this causes
the check_library_exists check fail making the build think that C
library isn't available.

To avoid this issue, we should use a symbol that isn't recognized by
Clang and wouldn't cause the same issue. __libc_start_main seems like
reasonable choice that fits the bill.

Differential Revision: https://reviews.llvm.org/D57142

llvm-svn: 352341
2019-01-28 04:12:54 +00:00
Petr Hosek 2d2e23e89b [CMake] Passthrough CFLAGS when checking the compiler-rt path
This is needed when cross-compiling for a different target since
CFLAGS may contain additional flags like -resource-dir which
change the location in which compiler-rt builtins are found.

Differential Revision: https://reviews.llvm.org/D54371

llvm-svn: 346820
2018-11-14 00:09:26 +00:00
Charles Davis 869e5d1fca [CMake] Link to compiler-rt if LIBUNWIND_USE_COMPILER_RT is ON.
Summary:
If `-nodefaultlibs` is given, we weren't actually linking to it. This
was true irrespective of passing `-rtlib=compiler-rt` (see previous
patch). Now we explicitly link it to handle that case.

I wonder if we should be linking these libraries only if we're using
`-nodefaultlibs`...

Reviewers: beanz

Subscribers: dberris, mgorny, christof, chrib, cfe-commits

Differential Revision: https://reviews.llvm.org/D51657

llvm-svn: 343990
2018-10-08 18:35:00 +00:00
Charles Davis 4c08654b17 [CMake] Don't use -rtlib=compiler-rt with -nodefaultlibs.
Summary:
This switch only has an effect at link time. It changes the default
compiler support library to `compiler-rt`. With `-nodefaultlibs`, this
library won't get linked anyway; Clang actually warns about that.

Reviewers: mstorsjo, rnk

Subscribers: dberris, mgorny, christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D51645

llvm-svn: 341404
2018-09-04 20:57:50 +00:00
Martin Storsjo faf9589fae [CMake] Convert paths to the right form in standalone builds on Windows
The paths output from llvm-config --cmakedir and from clang
--print-libgcc-file-name can contain backslashes, while CMake
can't handle the paths in this form.

This matches what compiler-rt already does (since SVN r203789
and r293195).

Differential Revision: https://reviews.llvm.org/D48353

llvm-svn: 335169
2018-06-20 20:53:19 +00:00
Saleem Abdulrasool 5b93ea3b9f build: use POSITION_INDEPENDENT_CODE instead of -fPIC
Rather than hardcode the flag and check if the compiler supports it, use
the CMake property to get the right flag spelling for the compiler.
This makes it generally more portable.

llvm-svn: 314834
2017-10-03 20:22:26 +00:00
Martin Storsjo 3a213316e9 Add CMake support for building for MinGW
This section is similar to what already exists in libcxx and libcxxabi.

Differential Revision: https://reviews.llvm.org/D38380

llvm-svn: 314716
2017-10-02 20:46:37 +00:00
Petr Hosek 9ad496b2c8 [CMake][libunwind] Fix the -target and -gcc-toolchain flag handling
CMake has the problem with the single dash variant because of the
space, so use the double dash with equal sign version. The compile
flag handling had a typo which caused these flag not to be properly
include. We also don't have to pass the target triple when checking
for compiler-rt since that flag is already included in compile flags
now.

Differential Revision: https://reviews.llvm.org/D32071

llvm-svn: 300419
2017-04-16 06:08:44 +00:00
Petr Hosek 57d49236cc Reland "[CMake][libunwind] Use -nodefaultlibs for CMake checks"
This is a reland of commit r299796.

Turned out that we need gcc_s or compiler-rt on ARM when checking
the support for -funwind-tables which creates a dependency on
__aeabi_unwind_cpp_pr0 symbol that's provided by the compiler
runtime.

Differential Revision: https://reviews.llvm.org/D31858

llvm-svn: 300020
2017-04-12 02:28:07 +00:00
Petr Hosek df82d93562 Revert "[CMake][libunwind] Use -nodefaultlibs for CMake checks"
This reverts commit r299796.

llvm-svn: 299798
2017-04-07 20:24:22 +00:00
Petr Hosek 3dc83e5e31 [CMake][libunwind] Use -nodefaultlibs for CMake checks
Since libunwind is built with -nodefaultlibs, we should be using this
option even for CMake checks to avoid any inconsistency and also to
avoid dependency on a working C++ standard library just for the setting
up the build itself. The implementation is largely similar to the one
used by libc++.

Differential Revision: https://reviews.llvm.org/D31640

llvm-svn: 299796
2017-04-07 20:10:29 +00:00
Petr Hosek 92e71965ad [CMake] Get libunwind building under LLVM/runtimes
The new LLVM runtimes directory requires the same conventions to be
followed across the runtime projects. These changes make libunwind
build under the runtimes subdirectory.

This patch contains the following changes:

* Rename LLVM_CONFIG to LLVM_CONFIG_PATH
* Check if compiler supports C++11 (required by libunwind)

Differential Revision: https://reviews.llvm.org/D26360

llvm-svn: 286308
2016-11-08 23:02:49 +00:00
Evgeniy Stepanov 9b44fa87f3 Replace cmake check for printf with a check for fopen.
Printf is a builtin, and the check fails with -Werror because of a clang
warning about an incompatible redeclaration.

llvm-svn: 255188
2015-12-10 00:47:08 +00:00
Saleem Abdulrasool c5d132b336 libunwind: add new build logic
This replicates most of the build infrastructure from libc++abi ported to
libunwind.  This allows building libunwind without requiring libc++abi.

llvm-svn: 235795
2015-04-25 01:46:35 +00:00