From 998a72c55d958bcc1869628318477532dc6e1ffa Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Thu, 6 Aug 2020 19:05:59 +0000 Subject: [PATCH] Reapply r354347 (by cem): Fix llvm-libunwind userspace build on ARM GCC's libgcc exports a few ARM-specific symbols for ARM EABI, AEABI, or EHABI or whatever it's called. Export the same ones from LLVM-libunwind's libgcc_s, on ARM. As part of this, convert libgcc_s from a direct Version.map to one constructed from component Symbol.map files. This allows the ARM-specific Symbol.map to be included only on ARM. Fix ARM-only oddities in struct name/aliases in LLVM-libunwind to match non-ARM definitions and ARM-specific expectations in libcxxrt / libcompiler_rt. No functional change intended for non-ARM architectures. This commit does not actually flip the switch for ARM defaults from libgcc to llvm-libunwind, but makes it possible (to compile, anyway). --- .../lib/builtins/gcc_personality_v0.c | 17 ++++++++++++++++- contrib/llvm-project/libunwind/include/unwind.h | 14 +++++++++----- 2 files changed, 25 insertions(+), 6 deletions(-) diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/gcc_personality_v0.c b/contrib/llvm-project/compiler-rt/lib/builtins/gcc_personality_v0.c index d12ee03c49fe..b986bd56943e 100644 --- a/contrib/llvm-project/compiler-rt/lib/builtins/gcc_personality_v0.c +++ b/contrib/llvm-project/compiler-rt/lib/builtins/gcc_personality_v0.c @@ -9,8 +9,23 @@ #include "int_lib.h" #include +/* + * XXX On FreeBSD, this file is compiled into three libraries: + * - libcompiler_rt + * - libgcc_eh + * - libgcc_s + * + * In the former, the include path points to the contrib/libcxxrt/unwind-arm.h + * copy of unwind.h. In the latter, the include path points to the + * contrib/libunwind/include/unwind.h header (LLVM libunwind). + * + * Neither (seemingly redundant) variant of unwind.h needs the redefinitions + * provided in the "helpful" header below, and libcxxrt's unwind-arm.h provides + * *no* useful distinguishing macros, so just forcibly disable the helper + * header on FreeBSD. + */ #if defined(__arm__) && !defined(__ARM_DWARF_EH__) && \ - !defined(__USING_SJLJ_EXCEPTIONS__) + !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__FreeBSD__) // When building with older compilers (e.g. clang <3.9), it is possible that we // have a version of unwind.h which does not provide the EHABI declarations // which are quired for the C personality to conform to the specification. In diff --git a/contrib/llvm-project/libunwind/include/unwind.h b/contrib/llvm-project/libunwind/include/unwind.h index 1d3444cd83b4..3a6cd116d33c 100644 --- a/contrib/llvm-project/libunwind/include/unwind.h +++ b/contrib/llvm-project/libunwind/include/unwind.h @@ -66,12 +66,16 @@ static const _Unwind_State _US_ACTION_MASK = 3; static const _Unwind_State _US_FORCE_UNWIND = 8; typedef uint32_t _Unwind_EHT_Header; +/* + * gcc_personality_v0 references 'struct _Unwind_Exception' all over the place. + * Nothing in libunwind cares about 'struct _Unwind_Control_Block,' so make it + * the alias of struct _Unwind_Exception, instead of the other way around. + */ +struct _Unwind_Exception; +typedef struct _Unwind_Exception _Unwind_Exception; +typedef struct _Unwind_Exception _Unwind_Control_Block; /* Alias */ -struct _Unwind_Control_Block; -typedef struct _Unwind_Control_Block _Unwind_Control_Block; -typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */ - -struct _Unwind_Control_Block { +struct _Unwind_Exception { uint64_t exception_class; void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);