Add fixes to libunwind (#1069)

Makefile

@@ -441,6 +441,7 @@ COSMOPOLITAN_OBJECTS =			\
 	LIBC_TIME			\
 	THIRD_PARTY_MUSL		\
 	THIRD_PARTY_ZLIB_GZ		\
+	THIRD_PARTY_LIBUNWIND		\
 	LIBC_STDIO			\
 	THIRD_PARTY_GDTOA		\
 	THIRD_PARTY_REGEX		\

libc/runtime/unwind.c

@@ -1,37 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/runtime/unwind.h"
-
-// temporary stubs for libunwind
-
-uintptr_t _Unwind_GetCFA(struct _Unwind_Context *ctx) {
-  return 0;
-}
-
-uintptr_t _Unwind_GetIP(struct _Unwind_Context *ctx) {
-  return 0;
-}
-
-_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn fn, void *arg) {
-  return _URC_NORMAL_STOP;
-}
-
-void *_Unwind_FindEnclosingFunction(void *arg) {
-  return NULL;
-}

libc/runtime/unwind.h

@@ -1,40 +0,0 @@
-#ifndef COSMOPOLITAN_LIBC_RUNTIME_UNWIND_H_
-#define COSMOPOLITAN_LIBC_RUNTIME_UNWIND_H_
-
-#define UNW_TDEP_CURSOR_LEN 127
-
-COSMOPOLITAN_C_START_
-
-typedef enum {
-  _URC_NO_REASON = 0,
-  _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
-  _URC_FATAL_PHASE2_ERROR = 2,
-  _URC_FATAL_PHASE1_ERROR = 3,
-  _URC_NORMAL_STOP = 4,
-  _URC_END_OF_STACK = 5,
-  _URC_HANDLER_FOUND = 6,
-  _URC_INSTALL_CONTEXT = 7,
-  _URC_CONTINUE_UNWIND = 8
-} _Unwind_Reason_Code;
-
-typedef uint64_t unw_word_t;
-
-typedef struct unw_cursor {
-  unw_word_t opaque[UNW_TDEP_CURSOR_LEN];
-} unw_cursor_t;
-
-struct _Unwind_Context {
-  unw_cursor_t cursor;
-  int end_of_stack;
-};
-
-typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
-                                                void *);
-
-uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
-uintptr_t _Unwind_GetIP(struct _Unwind_Context *);
-_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
-void *_Unwind_FindEnclosingFunction(void *);
-
-COSMOPOLITAN_C_END_
-#endif /* COSMOPOLITAN_LIBC_RUNTIME_UNWIND_H_ */

third_party/libunwind/README.cosmo

@@ -11,3 +11,6 @@ ORIGIN
   Author: Tobias Hieta <tobias@hieta.se>
   Date:   Tue, 28 Nov 2023 09:52:28 +0100
 
+LOCAL CHANGES
+  - Fixed `_Unwind_FunctionContext` struct to be ABI-compatible with code
+  generated by GCC.

third_party/libunwind/Unwind-sjlj.c

@@ -28,6 +28,8 @@
 
 #if defined(_LIBUNWIND_BUILD_SJLJ_APIS)
 
+typedef uintptr_t _Unwind_Word __attribute__((__mode__(__unwind_word__)));
+
 struct _Unwind_FunctionContext {
   // next function in stack of handlers
   struct _Unwind_FunctionContext *prev;
@@ -47,7 +49,7 @@ struct _Unwind_FunctionContext {
   uint32_t                        resumeLocation;
 
   // set by personality handler to be parameters passed to landing pad function
-  uint32_t                        resumeParameters[4];
+  _Unwind_Word                    resumeParameters[4];
 #endif
 
   // set by calling function before registering