Commit ad7497b3 authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r243073: 

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r243073 | logan | 2015-07-23 17:16:48 -0700 (Thu, 23 Jul 2015) | 10 lines

unwind: Fix libc++abi and libgcc build.

To build libc++abi without libunwind, we should make sure that all
function calls to _Unwind_{Get,Set}{GR,IP}() are inlined as function
calls to _Unwind_VRS_{Get,Set}().  Otherwise, libc++abi.so will fail to
link since libgcc does not provide these symbol at all.

This commit fixes the problem by providing both the inlined version and
exported version.

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llvm-svn: 243437
parent 0a5b126d

libunwind/include/unwind.h

+43 −0
Original line number Diff line number Diff line
@@ -204,12 +204,55 @@ _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 
                _Unwind_VRS_DataRepresentation representation);

#endif



#if !_LIBUNWIND_ARM_EHABI



extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);

extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,

                          uintptr_t new_value);

extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);

extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);



#else  // _LIBUNWIND_ARM_EHABI



#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)

#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern

#else

#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__

#endif



// These are de facto helper functions for ARM, which delegate the function

// calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI

// specification, thus these function MUST be inlined.  Please don't replace

// these with the "extern" function declaration; otherwise, the program

// including this <unwind.h> header won't be ABI compatible and will result in

// link error when we are linking the program with libgcc.



_LIBUNWIND_EXPORT_UNWIND_LEVEL1

uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {

  uintptr_t value = 0;

  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);

  return value;

}



_LIBUNWIND_EXPORT_UNWIND_LEVEL1

void _Unwind_SetGR(struct _Unwind_Context *context, int index,

                   uintptr_t value) {

  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);

}



_LIBUNWIND_EXPORT_UNWIND_LEVEL1

uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {

  // remove the thumb-bit before returning

  return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);

}



_LIBUNWIND_EXPORT_UNWIND_LEVEL1

void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {

  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);

  _Unwind_SetGR(context, 15, value | thumb_bit);

}

#endif  // _LIBUNWIND_ARM_EHABI



extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);

extern uintptr_t

    _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);

libunwind/src/UnwindLevel1.c

+7 −35
Original line number Diff line number Diff line
@@ -12,6 +12,13 @@ 
//

//===----------------------------------------------------------------------===//



// ARM EHABI does not specify _Unwind_{Get,Set}{GR,IP}().  Thus, we are

// defining inline functions to delegate the function calls to

// _Unwind_VRS_{Get,Set}().  However, some applications might declare the

// function protetype directly (instead of including <unwind.h>), thus we need

// to export these functions from libunwind.so as well.

#define _LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE 1



#include <inttypes.h>

#include <stdint.h>

#include <stdbool.h>
@@ -496,39 +503,4 @@ _LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context, 
  unw_set_reg(cursor, UNW_REG_IP, value);

}



#else



_LIBUNWIND_EXPORT uintptr_t

_Unwind_GetGR(struct _Unwind_Context *context, int index) {

  uintptr_t value = 0;

  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);

  _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIx64 "\n",

                       (void *)context, index, (uint64_t)value);

  return value;

}



_LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,

                                     uintptr_t value) {

  _LIBUNWIND_TRACE_API("_Unwind_SetGR(context=%p, reg=%d, value=0x%0"PRIx64")\n",

                       (void *)context, index, (uint64_t)value);

  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);

}



_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {

  // remove the thumb-bit before returning

  uintptr_t value = _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);

  _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIx64 "\n",

                       (void *)context, (uint64_t)value);

  return value;

}



_LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,

                                     uintptr_t value) {

  _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIx64 ")\n",

                       (void *)context, (uint64_t)value);

  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);

  _Unwind_SetGR(context, 15, value | thumb_bit);

}



#endif // !_LIBUNWIND_ARM_EHABI