diff options
Diffstat (limited to 'current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp')
| -rw-r--r-- | current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp b/current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp index ebb05ce54..09813e851 100644 --- a/current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp +++ b/current/sources/cxx-stl/llvm-libc++abi/src/cxa_exception.cpp @@ -341,8 +341,11 @@ unwinding with _Unwind_Resume. According to ARM EHABI 8.4.1, __cxa_end_cleanup() should not clobber any register, thus we have to write this function in assembly so that we can save {r1, r2, r3}. We don't have to save r0 because it is the return value and the -first argument to _Unwind_Resume(). In addition, we are saving r4 in order to -align the stack to 16 bytes, even though it is a callee-save register. +first argument to _Unwind_Resume(). The function also saves/restores r4 to +keep the stack aligned and to provide a temp register. _Unwind_Resume never +returns and we need to keep the original lr so just branch to it. When +targeting bare metal, the function also clobbers ip/r12 to hold the address of +_Unwind_Resume, which may be too far away for an ordinary branch. */ __attribute__((used)) static _Unwind_Exception * __cxa_end_cleanup_impl() @@ -372,19 +375,29 @@ __cxa_end_cleanup_impl() return &exception_header->unwindHeader; } -asm ( - " .pushsection .text.__cxa_end_cleanup,\"ax\",%progbits\n" +asm(" .pushsection .text.__cxa_end_cleanup,\"ax\",%progbits\n" " .globl __cxa_end_cleanup\n" " .type __cxa_end_cleanup,%function\n" "__cxa_end_cleanup:\n" +#if defined(__ARM_FEATURE_BTI_DEFAULT) + " bti\n" +#endif " push {r1, r2, r3, r4}\n" + " mov r4, lr\n" " bl __cxa_end_cleanup_impl\n" + " mov lr, r4\n" +#if defined(LIBCXXABI_BAREMETAL) + " ldr r4, =_Unwind_Resume\n" + " mov ip, r4\n" +#endif " pop {r1, r2, r3, r4}\n" - " bl _Unwind_Resume\n" - " bl abort\n" - " .popsection" -); -#endif // defined(_LIBCXXABI_ARM_EHABI) +#if defined(LIBCXXABI_BAREMETAL) + " bx ip\n" +#else + " b _Unwind_Resume\n" +#endif + " .popsection"); +#endif // defined(_LIBCXXABI_ARM_EHABI) /* This routine can catch foreign or native exceptions. If native, the exception |