//===--------------------- UnwindLevel1-gcc-ext.c -------------------------===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is dual licensed under the MIT and the University of Illinois Open

// Source Licenses. See LICENSE.TXT for details.

//

//

//  Implements gcc extensions to the C++ ABI Exception Handling Level 1.

//

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

#include <inttypes.h>

#include <stdbool.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "config.h"

#include "libunwind_ext.h"

#include "libunwind.h"

#include "Unwind-EHABI.h"

#include "unwind.h"

#if _LIBUNWIND_BUILD_ZERO_COST_APIS

///  Called by __cxa_rethrow().

_LIBUNWIND_EXPORT _Unwind_Reason_Code

_Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object) {

#if _LIBUNWIND_ARM_EHABI

  _LIBUNWIND_TRACE_API("_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%ld\n",

                       (void *)exception_object,

                       (long)exception_object->unwinder_cache.reserved1);

#else

                       (void *)exception_object,

                       (long)exception_object->private_1);

#endif

#if _LIBUNWIND_ARM_EHABI

  // _Unwind_RaiseException on EHABI will always set the reserved1 field to 0,

  // which is in the same position as private_1 below.

  return _Unwind_RaiseException(exception_object);

#else

  // If this is non-forced and a stopping place was found, then this is a

  // re-throw.

  // Call _Unwind_RaiseException() as if this was a new exception

    // Will return if there is no catch clause, so that __cxa_rethrow can call

    // std::terminate().

  }

  // Call through to _Unwind_Resume() which distiguishes between forced and

  // regular exceptions.

                   " which unexpectedly returned");

#endif

}

/// Called by personality handler during phase 2 to get base address for data

/// relative encodings.

_LIBUNWIND_EXPORT uintptr_t

_Unwind_GetDataRelBase(struct _Unwind_Context *context) {

  (void)context;

}

/// Called by personality handler during phase 2 to get base address for text

/// relative encodings.

_LIBUNWIND_EXPORT uintptr_t

_Unwind_GetTextRelBase(struct _Unwind_Context *context) {

  (void)context;

}

/// Scans unwind information to find the function that contains the

/// specified code address "pc".

_LIBUNWIND_EXPORT void *_Unwind_FindEnclosingFunction(void *pc) {

  // This is slow, but works.

  // We create an unwind cursor then alter the IP to be pc

  else

}

/// Walk every frame and call trace function at each one.  If trace function

/// returns anything other than _URC_NO_REASON, then walk is terminated.

_LIBUNWIND_EXPORT _Unwind_Reason_Code

_Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {

                       (void *)(uintptr_t)callback);

#if _LIBUNWIND_ARM_EHABI

  // Create a mock exception object for force unwinding.

  _Unwind_Exception ex;

  memset(&ex, '\0', sizeof(ex));

  ex.exception_class = 0x434C4E47554E5700; // CLNGUNW\0

#endif

  // walk each frame

  while (true) {

    _Unwind_Reason_Code result;

#if !_LIBUNWIND_ARM_EHABI

    // ask libuwind to get next frame (skip over first frame which is

    // _Unwind_Backtrace())

                                 "bottom of stack, returning %d\n",

                                 _URC_END_OF_STACK);

    }

#else

    // Get the information for this frame.

    unw_proc_info_t frameInfo;

    if (unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {

      return _URC_END_OF_STACK;

    }

    // Update the pr_cache in the mock exception object.

    const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;

    ex.pr_cache.fnstart = frameInfo.start_ip;

    ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;

    ex.pr_cache.additional= frameInfo.flags;

    struct _Unwind_Context *context = (struct _Unwind_Context *)&cursor;

    // Get and call the personality function to unwind the frame.

    __personality_routine handler = (__personality_routine) frameInfo.handler;

    if (handler == NULL) {

      return _URC_END_OF_STACK;

    }

    if (handler(_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, &ex, context) !=

            _URC_CONTINUE_UNWIND) {

      return _URC_END_OF_STACK;

    }

#endif // _LIBUNWIND_ARM_EHABI

    // debugging

          " _backtrace: start_ip=0x%llX, func=%s, lsda=0x%llX, context=%p\n",

          (long long)frame.start_ip, functionName, (long long)frame.lsda,

          (void *)&cursor);

    }

    // call trace function with this frame

          " _backtrace: ended because callback returned %d\n", result);

    }

  }

}

/// Find dwarf unwind info for an address 'pc' in some function.

_LIBUNWIND_EXPORT const void *_Unwind_Find_FDE(const void *pc,

                                               struct dwarf_eh_bases *bases) {

  // This is slow, but works.

  // We create an unwind cursor then alter the IP to be pc

                  (void *)(long) info.unwind_info);

}

/// Returns the CFA (call frame area, or stack pointer at start of function)

/// for the current context.

_LIBUNWIND_EXPORT uintptr_t _Unwind_GetCFA(struct _Unwind_Context *context) {

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

}

/// Called by personality handler during phase 2 to get instruction pointer.

/// ipBefore is a boolean that says if IP is already adjusted to be the call

/// site address.  Normally IP is the return address.

_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,

                                              int *ipBefore) {

}

#if _LIBUNWIND_SUPPORT_DWARF_UNWIND

/// Called by programs with dynamic code generators that want

/// to register a dynamically generated FDE.

/// This function has existed on Mac OS X since 10.4, but

/// was broken until 10.6.

_LIBUNWIND_EXPORT void __register_frame(const void *fde) {

}

/// Called by programs with dynamic code generators that want

/// to unregister a dynamically generated FDE.

/// This function has existed on Mac OS X since 10.4, but

/// was broken until 10.6.

_LIBUNWIND_EXPORT void __deregister_frame(const void *fde) {

}

// The following register/deregister functions are gcc extensions.

// They have existed on Mac OS X, but have never worked because Mac OS X

// before 10.6 used keymgr to track known FDEs, but these functions

// never got updated to use keymgr.

// For now, we implement these as do-nothing functions to keep any existing

// applications working.  We also add the not in 10.6 symbol so that nwe

// application won't be able to use them.

#if _LIBUNWIND_SUPPORT_FRAME_APIS

_LIBUNWIND_EXPORT void __register_frame_info_bases(const void *fde, void *ob,

                                                   void *tb, void *db) {

  (void)fde;

  (void)ob;

  (void)tb;

  (void)db;

                            fde, ob, tb, db);

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void __register_frame_info(const void *fde, void *ob) {

  (void)fde;

  (void)ob;

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void __register_frame_info_table_bases(const void *fde,

                                                         void *ob, void *tb,

                                                         void *db) {

  (void)fde;

  (void)ob;

  (void)tb;

  (void)db;

                             "(%p,%p, %p, %p)\n", fde, ob, tb, db);

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void __register_frame_info_table(const void *fde, void *ob) {

  (void)fde;

  (void)ob;

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void __register_frame_table(const void *fde) {

  (void)fde;

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void *__deregister_frame_info(const void *fde) {

  (void)fde;

  // do nothing, this function never worked in Mac OS X

}

_LIBUNWIND_EXPORT void *__deregister_frame_info_bases(const void *fde) {

  (void)fde;

  // do nothing, this function never worked in Mac OS X

}

#endif // _LIBUNWIND_SUPPORT_FRAME_APIS

#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND

#endif // _LIBUNWIND_BUILD_ZERO_COST_APIS