If unwinding stops due to hitting the end of the call chain, the return
value is supposed to be _URC_END_OF_STACK; other values indicate internal
errors. The return value from get_eit_entry() is now returned without
translating it to _URC_FAILURE, so that callers can see _URC_END_OF_STACK
when it happens.
When raising an exception, the unwinder searches for a catch handler and if
none is found it should invoke std::terminate() with the uncaught exception
as the "current" exception. Before this change, the terminate handler was
invoked with no exception as current (abi::__cxa_current_exception_type()
returned NULL), because the return value from the unwinder indicated an
internal failure in unwinding. It turns out that was because all errors
from get_eit_entry() were translated to _URC_FAILURE. Now the error is
returned untranslated, which allows _URC_END_OF_STACK to percolate upwards
to throw_exception() in libcxxrt. When it sees that return status it
properly calls std::terminate() with the uncaught exception installed
as the current exception, allowing custom terminate handlers to work
with it.
In real GNU libgcc, _Unwind_Backtrace is published with GCC_3.3 version
for all architectures but ARM. For ARM it's publishes with GCC_4.3.0
version.
This exception is not implement in your version of libggc, thus we
export _Unwind_Backtrace with bad version. To maintain backward
compatibility, publish _Unwind_Backtrace twice, once as compatible
symbol with GCC_3.3 version, and once as default symbol with
GCC_4.3.0 version.
While I'm in, fix typo in GCC_4.2.0 to GCC_4.3.0 inheritance declaration.
MFC after: 2 weeks
llvm libunwind includes a libunwind.cpp, but on ARM libunwind.S is found
first in .PATH. Rename the latter one, since it is not going to be
updated again.
Reviewed by: andrew
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7162
This will result in __ARM_ARCH_7A__ being defined during the compile.
When compiling with gcc, it will still only generate armv6 opcodes itself,
but should pass the arch to gas so that inline asm can use v7 opcodes.
Very small updates: fixes GCC-PR target/31152
Tested by building the cross-compiler.
Obtained from: gcc 4.3 (rev. r118461, 125973: GPLv2)
MFC after: 2 weeks
_Unwind_ForcedUnwind in libgcc_s takes as one of it's parameters a stop
function to tell it when to stop unwinding. One of the stop function's
parameters is a _Unwind_Exception_Class. On most architectures this is an
int64_t, however on ARM EABI the gcc developers have made this a char array
with 8 items. While both of these take the same space they are passed into
the stop function differently, an int64_t is passed in in registers r2 and
r3, while the char[8] is passed in as a pointer to the first item in
register r2.
Because libthr expects the value to be an int64_t we would get incorrect
results when it passes a function that take an int64_t but libgcc passes in
a pointer to a char array including crashing.
The fix is to update libgcc_s to make it pass an int64_t to the stop
function and to libstdc++ as it expects _Unwind_Exception_Class to be an
array.
ARM EABI support is disabled by default and can be enabled by setting
WITH_ARM_EABI when building, however only the kernel-toolchain target will
work with this flag until the rest of the support is added.
built with clang. When these are defined the lists are defined similar to:
asm(".section .ctors");
STATIC func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) };
asm(".section .dtors");
STATIC func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) };
The problem is clang will move the two arrays out of the .ctors and .dtors
sections causing these sections to contain a single null address. By not
defining these macros we use the version of the code that places the arrays
is their sections by using __attribute__((section(".ctors"))) and similar
for .dtors.
Submitted by: Daisuke Aoyama <aoyama AT peach.ne.jp>
r238211:
Support TARGET_ARCH=armv6 and TARGET_ARCH=armv6eb
This adds a new TARGET_ARCH for building on ARM
processors that support the ARMv6K multiprocessor
extensions. In particular, these processors have
better support for TLS and mutex operations.
This mostly touches a lot of Makefiles to extend
existing patterns for inferring CPUARCH from ARCH.
It also configures:
* GCC to default to arm1176jz-s
* GCC to predefine __FreeBSD_ARCH_armv6__
* gas to default to ARM_ARCH_V6K
* uname -p to return 'armv6'
* make so that MACHINE_ARCH defaults to 'armv6'
It also changes a number of headers to use
the compiler __ARM_ARCH_XXX__ macros to configure
processor-specific support routines.
Submitted by: Tim Kientzle <kientzle@freebsd.org>
desired, one can turn off the generation of post-ELF standard dtags by
overriding it with --disable-new-dtags after the default switch.
Immediate effect of the change is that -rpath path is now stored both
in DT_RPATH and DT_RUNPATH tags, which is the right way to provide
rpath for dynamic linker supporting DT_RUNPATH per specification.
Reviewed by: kan
MFC after: 1 month
