[PATCH] Align libexecinfo unwind.h types to the same clang/gcc header

[Michał Górny <mgorny%gentoo.org@localhost>]

Update the types and function prototypes used in libexecinfo's unwind.h
to match the more commonly used variants found in clang and gcc.  This
fixes compatibility problems with C++ programs where type mismatches
are errors, and upstreams assume the more common prototypes.  This is
needed to fix compiler-rt and libc++abi builds while not causing any
issues with libexecinfo or other components of src.

This should not cause ABI breakage.

More specifically:

- make _Unwind_Ptr a uintptr_t rather than a real pointer

- ensure that _Unwind_Word is always word length

- switch _Unwind_Reason_Code and _Unwind_Action to enums

- switch _Unwind_GetIP(), _Unwind_GetIPInfo() and _Unwind_SetIP()
  to use _Unwind_Word instead of _Unwind_Ptr

- switch _Unwind_GetLanguageSpecificData() return void * instead of
  _Unwind_Ptr

- switch _Unwind_SetGR() to use _Unwind_Word, therefore making it
  consistent with _Unwind_GetGR()
---
 lib/libexecinfo/unwind.h | 52 +++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 25 deletions(-)

diff --git a/lib/libexecinfo/unwind.h b/lib/libexecinfo/unwind.h
index 044ecdff29b4..dc99cd38f194 100644
--- a/lib/libexecinfo/unwind.h
+++ b/lib/libexecinfo/unwind.h
@@ -34,26 +34,28 @@
 __BEGIN_DECLS
 struct _Unwind_Context;
 struct _Unwind_Exception;
-typedef int _Unwind_Reason_Code;
-typedef int _Unwind_Action;
-typedef void *_Unwind_Ptr;
-typedef long _Unwind_Word;
-
-#define	_UA_SEARCH_PHASE	0x01
-#define	_UA_CLEANUP_PHASE	0x02
-#define	_UA_HANDLER_FRAME 	0x04
-#define	_UA_FORCE_UNWIND	0x08
-#define	_UA_END_OF_STACK 	0x10
-
-#define	_URC_NO_REASON			0
-#define	_URC_FOREIGN_EXCEPTION_CAUGHT	1
-#define	_URC_FATAL_PHASE2_ERROR		2
-#define	_URC_FATAL_PHASE1_ERROR		3
-#define	_URC_NORMAL_STOP		4
-#define	_URC_END_OF_STACK		5
-#define	_URC_HANDLER_FOUND		6
-#define	_URC_INSTALL_CONTEXT		7
-#define	_URC_CONTINUE_UNWIND		8
+typedef uintptr_t _Unwind_Ptr;
+typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
+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,
+	_URC_MAXTYPE			= 0x7fffffff
+} _Unwind_Reason_Code;
+typedef enum {
+	_UA_SEARCH_PHASE	= 0x01,
+	_UA_CLEANUP_PHASE	= 0x02,
+	_UA_HANDLER_FRAME	= 0x04,
+	_UA_FORCE_UNWIND	= 0x08,
+	_UA_END_OF_STACK	= 0x10,
+	_UA_MAXTYPE		= 0x7fffffff
+} _Unwind_Action;
 
 struct _Unwind_Exception {
 	uint64_t exception_class;
@@ -80,9 +82,9 @@ _Unwind_Reason_Code 	 _Unwind_ForcedUnwind(struct _Unwind_Exception *,
 _Unwind_Word		 _Unwind_GetCFA(struct _Unwind_Context *);
 _Unwind_Ptr		 _Unwind_GetDataRelBase(struct _Unwind_Context *);
 _Unwind_Word 		 _Unwind_GetGR(struct _Unwind_Context *, int);
-_Unwind_Ptr		 _Unwind_GetIP(struct _Unwind_Context *);
-_Unwind_Ptr		 _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
-_Unwind_Ptr		 _Unwind_GetLanguageSpecificData(
+_Unwind_Word		 _Unwind_GetIP(struct _Unwind_Context *);
+_Unwind_Word		 _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
+void 			*_Unwind_GetLanguageSpecificData(
     struct _Unwind_Context *);
 _Unwind_Ptr		 _Unwind_GetRegionStart(struct _Unwind_Context *);
 _Unwind_Ptr		 _Unwind_GetTextRelBase(struct _Unwind_Context *);
@@ -90,7 +92,7 @@ _Unwind_Reason_Code	 _Unwind_RaiseException(struct _Unwind_Exception *);
 void			 _Unwind_Resume(struct _Unwind_Exception *);
 _Unwind_Reason_Code	 _Unwind_Resume_or_Rethrow(struct _Unwind_Exception *);
 void			 _Unwind_SetGR(struct _Unwind_Context *, int,
-    _Unwind_Ptr);
-void			 _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Ptr);
+    _Unwind_Word);
+void			 _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Word);
 __END_DECLS
 #endif /* _UNWIND_H_ */
-- 
2.24.1