| Index: third_party/libc++abi/src/Unwind/Unwind-sjlj.c
|
| ===================================================================
|
| --- third_party/libc++abi/src/Unwind/Unwind-sjlj.c (revision 0)
|
| +++ third_party/libc++abi/src/Unwind/Unwind-sjlj.c (revision 0)
|
| @@ -0,0 +1,468 @@
|
| +//===--------------------------- Unwind-sjlj.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 setjump-longjump based C++ exceptions
|
| +//
|
| +//===----------------------------------------------------------------------===//
|
| +
|
| +#include <unwind.h>
|
| +
|
| +#include <stdint.h>
|
| +#include <stdbool.h>
|
| +#include <stdlib.h>
|
| +
|
| +#include "config.h"
|
| +#include "unwind_ext.h"
|
| +
|
| +//
|
| +// 32-bit iOS uses setjump/longjump based C++ exceptions.
|
| +// Other architectures use "zero cost" exceptions.
|
| +//
|
| +// With SJLJ based exceptions, any function that has a catch clause or needs to
|
| +// do any clean up when an exception propagates through it, needs to call
|
| +// _Unwind_SjLj_Register() at the start of the function and
|
| +// _Unwind_SjLj_Unregister() at the end. The register function is called with
|
| +// the address of a block of memory in the function's stack frame. The runtime
|
| +// keeps a linked list (stack) of these blocks - one per thread. The calling
|
| +// function also sets the personality and lsda fields of the block.
|
| +//
|
| +
|
| +#if _LIBUNWIND_BUILD_SJLJ_APIS
|
| +
|
| +struct _Unwind_FunctionContext {
|
| + // next function in stack of handlers
|
| + struct _Unwind_FunctionContext *prev;
|
| +
|
| + // set by calling function before registering to be the landing pad
|
| + uintptr_t resumeLocation;
|
| +
|
| + // set by personality handler to be parameters passed to landing pad function
|
| + uintptr_t resumeParameters[4];
|
| +
|
| + // set by calling function before registering
|
| + __personality_routine personality; // arm offset=24
|
| + uintptr_t lsda; // arm offset=28
|
| +
|
| + // variable length array, contains registers to restore
|
| + // 0 = r7, 1 = pc, 2 = sp
|
| + void *jbuf[];
|
| +};
|
| +
|
| +
|
| +/// Called at start of each function that catches exceptions
|
| +_LIBUNWIND_EXPORT void
|
| +_Unwind_SjLj_Register(struct _Unwind_FunctionContext *fc) {
|
| + fc->prev = __Unwind_SjLj_GetTopOfFunctionStack();
|
| + __Unwind_SjLj_SetTopOfFunctionStack(fc);
|
| +}
|
| +
|
| +
|
| +/// Called at end of each function that catches exceptions
|
| +_LIBUNWIND_EXPORT void
|
| +_Unwind_SjLj_Unregister(struct _Unwind_FunctionContext *fc) {
|
| + __Unwind_SjLj_SetTopOfFunctionStack(fc->prev);
|
| +}
|
| +
|
| +
|
| +static _Unwind_Reason_Code
|
| +unwind_phase1(struct _Unwind_Exception *exception_object) {
|
| + _Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1: initial function-context=%p\n", c);
|
| +
|
| + // walk each frame looking for a place to stop
|
| + for (bool handlerNotFound = true; handlerNotFound; c = c->prev) {
|
| +
|
| + // check for no more frames
|
| + if (c == NULL) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): reached "
|
| + "bottom => _URC_END_OF_STACK\n",
|
| + exception_object);
|
| + return _URC_END_OF_STACK;
|
| + }
|
| +
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1: function-context=%p\n", c);
|
| + // if there is a personality routine, ask it if it will want to stop at this
|
| + // frame
|
| + if (c->personality != NULL) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): calling "
|
| + "personality function %p\n",
|
| + exception_object, c->personality);
|
| + _Unwind_Reason_Code personalityResult = (*c->personality)(
|
| + 1, _UA_SEARCH_PHASE, exception_object->exception_class,
|
| + exception_object, (struct _Unwind_Context *)c);
|
| + switch (personalityResult) {
|
| + case _URC_HANDLER_FOUND:
|
| + // found a catch clause or locals that need destructing in this frame
|
| + // stop search and remember function context
|
| + handlerNotFound = false;
|
| + exception_object->private_2 = (uintptr_t) c;
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
|
| + "_URC_HANDLER_FOUND\n", exception_object);
|
| + return _URC_NO_REASON;
|
| +
|
| + case _URC_CONTINUE_UNWIND:
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
|
| + "_URC_CONTINUE_UNWIND\n", exception_object);
|
| + // continue unwinding
|
| + break;
|
| +
|
| + default:
|
| + // something went wrong
|
| + _LIBUNWIND_TRACE_UNWINDING(
|
| + "unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",
|
| + exception_object);
|
| + return _URC_FATAL_PHASE1_ERROR;
|
| + }
|
| + }
|
| + }
|
| + return _URC_NO_REASON;
|
| +}
|
| +
|
| +
|
| +static _Unwind_Reason_Code
|
| +unwind_phase2(struct _Unwind_Exception *exception_object) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n", exception_object);
|
| +
|
| + // walk each frame until we reach where search phase said to stop
|
| + _Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
|
| + while (true) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2s(ex_ojb=%p): context=%p\n",
|
| + exception_object, c);
|
| +
|
| + // check for no more frames
|
| + if (c == NULL) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
|
| + "bottom => _URC_END_OF_STACK\n",
|
| + exception_object);
|
| + return _URC_END_OF_STACK;
|
| + }
|
| +
|
| + // if there is a personality routine, tell it we are unwinding
|
| + if (c->personality != NULL) {
|
| + _Unwind_Action action = _UA_CLEANUP_PHASE;
|
| + if ((uintptr_t) c == exception_object->private_2)
|
| + action = (_Unwind_Action)(
|
| + _UA_CLEANUP_PHASE |
|
| + _UA_HANDLER_FRAME); // tell personality this was the frame it marked
|
| + // in phase 1
|
| + _Unwind_Reason_Code personalityResult =
|
| + (*c->personality)(1, action, exception_object->exception_class,
|
| + exception_object, (struct _Unwind_Context *)c);
|
| + switch (personalityResult) {
|
| + case _URC_CONTINUE_UNWIND:
|
| + // continue unwinding
|
| + _LIBUNWIND_TRACE_UNWINDING(
|
| + "unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
|
| + exception_object);
|
| + if ((uintptr_t) c == exception_object->private_2) {
|
| + // phase 1 said we would stop at this frame, but we did not...
|
| + _LIBUNWIND_ABORT("during phase1 personality function said it would "
|
| + "stop here, but now if phase2 it did not stop here");
|
| + }
|
| + break;
|
| + case _URC_INSTALL_CONTEXT:
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): "
|
| + "_URC_INSTALL_CONTEXT, will resume at "
|
| + "landing pad %p\n",
|
| + exception_object, c->jbuf[1]);
|
| + // personality routine says to transfer control to landing pad
|
| + // we may get control back if landing pad calls _Unwind_Resume()
|
| + __Unwind_SjLj_SetTopOfFunctionStack(c);
|
| + __builtin_longjmp(c->jbuf, 1);
|
| + // unw_resume() only returns if there was an error
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| + default:
|
| + // something went wrong
|
| + _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
|
| + personalityResult);
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| + }
|
| + }
|
| + c = c->prev;
|
| + }
|
| +
|
| + // clean up phase did not resume at the frame that the search phase said it
|
| + // would
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| +}
|
| +
|
| +
|
| +static _Unwind_Reason_Code
|
| +unwind_phase2_forced(struct _Unwind_Exception *exception_object,
|
| + _Unwind_Stop_Fn stop, void *stop_parameter) {
|
| + // walk each frame until we reach where search phase said to stop
|
| + _Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
|
| + while (true) {
|
| +
|
| + // get next frame (skip over first which is _Unwind_RaiseException)
|
| + if (c == NULL) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
|
| + "bottom => _URC_END_OF_STACK\n",
|
| + exception_object);
|
| + return _URC_END_OF_STACK;
|
| + }
|
| +
|
| + // call stop function at each frame
|
| + _Unwind_Action action =
|
| + (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
|
| + _Unwind_Reason_Code stopResult =
|
| + (*stop)(1, action, exception_object->exception_class, exception_object,
|
| + (struct _Unwind_Context *)c, stop_parameter);
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "stop function returned %d\n",
|
| + exception_object, stopResult);
|
| + if (stopResult != _URC_NO_REASON) {
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "stopped by stop function\n",
|
| + exception_object);
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| + }
|
| +
|
| + // if there is a personality routine, tell it we are unwinding
|
| + if (c->personality != NULL) {
|
| + __personality_routine p = (__personality_routine) c->personality;
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "calling personality function %p\n",
|
| + exception_object, p);
|
| + _Unwind_Reason_Code personalityResult =
|
| + (*p)(1, action, exception_object->exception_class, exception_object,
|
| + (struct _Unwind_Context *)c);
|
| + switch (personalityResult) {
|
| + case _URC_CONTINUE_UNWIND:
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "personality returned _URC_CONTINUE_UNWIND\n",
|
| + exception_object);
|
| + // destructors called, continue unwinding
|
| + break;
|
| + case _URC_INSTALL_CONTEXT:
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "personality returned _URC_INSTALL_CONTEXT\n",
|
| + exception_object);
|
| + // we may get control back if landing pad calls _Unwind_Resume()
|
| + __Unwind_SjLj_SetTopOfFunctionStack(c);
|
| + __builtin_longjmp(c->jbuf, 1);
|
| + break;
|
| + default:
|
| + // something went wrong
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
|
| + "personality returned %d, "
|
| + "_URC_FATAL_PHASE2_ERROR\n",
|
| + exception_object, personalityResult);
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| + }
|
| + }
|
| + c = c->prev;
|
| + }
|
| +
|
| + // call stop function one last time and tell it we've reached the end of the
|
| + // stack
|
| + _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
|
| + "function with _UA_END_OF_STACK\n",
|
| + exception_object);
|
| + _Unwind_Action lastAction =
|
| + (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
|
| + (*stop)(1, lastAction, exception_object->exception_class, exception_object,
|
| + (struct _Unwind_Context *)c, stop_parameter);
|
| +
|
| + // clean up phase did not resume at the frame that the search phase said it
|
| + // would
|
| + return _URC_FATAL_PHASE2_ERROR;
|
| +}
|
| +
|
| +
|
| +/// Called by __cxa_throw. Only returns if there is a fatal error
|
| +_LIBUNWIND_EXPORT _Unwind_Reason_Code
|
| +_Unwind_SjLj_RaiseException(struct _Unwind_Exception *exception_object) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_SjLj_RaiseException(ex_obj=%p)\n", exception_object);
|
| +
|
| + // mark that this is a non-forced unwind, so _Unwind_Resume() can do the right
|
| + // thing
|
| + exception_object->private_1 = 0;
|
| + exception_object->private_2 = 0;
|
| +
|
| + // phase 1: the search phase
|
| + _Unwind_Reason_Code phase1 = unwind_phase1(exception_object);
|
| + if (phase1 != _URC_NO_REASON)
|
| + return phase1;
|
| +
|
| + // phase 2: the clean up phase
|
| + return unwind_phase2(exception_object);
|
| +}
|
| +
|
| +
|
| +
|
| +/// When _Unwind_RaiseException() is in phase2, it hands control
|
| +/// to the personality function at each frame. The personality
|
| +/// may force a jump to a landing pad in that function, the landing
|
| +/// pad code may then call _Unwind_Resume() to continue with the
|
| +/// unwinding. Note: the call to _Unwind_Resume() is from compiler
|
| +/// geneated user code. All other _Unwind_* routines are called
|
| +/// by the C++ runtime __cxa_* routines.
|
| +///
|
| +/// Re-throwing an exception is implemented by having the code call
|
| +/// __cxa_rethrow() which in turn calls _Unwind_Resume_or_Rethrow()
|
| +_LIBUNWIND_EXPORT void
|
| +_Unwind_SjLj_Resume(struct _Unwind_Exception *exception_object) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_SjLj_Resume(ex_obj=%p)\n", exception_object);
|
| +
|
| + if (exception_object->private_1 != 0)
|
| + unwind_phase2_forced(exception_object,
|
| + (_Unwind_Stop_Fn) exception_object->private_1,
|
| + (void *)exception_object->private_2);
|
| + else
|
| + unwind_phase2(exception_object);
|
| +
|
| + // clients assume _Unwind_Resume() does not return, so all we can do is abort.
|
| + _LIBUNWIND_ABORT("_Unwind_SjLj_Resume() can't return");
|
| +}
|
| +
|
| +
|
| +/// Called by __cxa_rethrow().
|
| +_LIBUNWIND_EXPORT _Unwind_Reason_Code
|
| +_Unwind_SjLj_Resume_or_Rethrow(struct _Unwind_Exception *exception_object) {
|
| + _LIBUNWIND_TRACE_API("__Unwind_SjLj_Resume_or_Rethrow(ex_obj=%p), "
|
| + "private_1=%ld\n",
|
| + exception_object, exception_object->private_1);
|
| + // 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.
|
| + if (exception_object->private_1 == 0) {
|
| + return _Unwind_SjLj_RaiseException(exception_object);
|
| + // should 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.
|
| + _Unwind_SjLj_Resume(exception_object);
|
| + _LIBUNWIND_ABORT("__Unwind_SjLj_Resume_or_Rethrow() called "
|
| + "_Unwind_SjLj_Resume() which unexpectedly returned");
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to get LSDA for current frame.
|
| +_LIBUNWIND_EXPORT uintptr_t
|
| +_Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetLanguageSpecificData(context=%p) "
|
| + "=> 0x%0lX\n", context, ufc->lsda);
|
| + return ufc->lsda;
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to get register values.
|
| +_LIBUNWIND_EXPORT uintptr_t _Unwind_GetGR(struct _Unwind_Context *context,
|
| + int index) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d)\n",
|
| + context, index);
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + return ufc->resumeParameters[index];
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to alter register values.
|
| +_LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,
|
| + uintptr_t new_value) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_SetGR(context=%p, reg=%d, value=0x%0lX)\n"
|
| + , context, index, new_value);
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + ufc->resumeParameters[index] = new_value;
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to get instruction pointer.
|
| +_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%lX\n", context,
|
| + ufc->resumeLocation + 1);
|
| + return ufc->resumeLocation + 1;
|
| +}
|
| +
|
| +
|
| +/// 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) {
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + *ipBefore = 0;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetIPInfo(context=%p, %p) => 0x%lX\n",
|
| + context, ipBefore, ufc->resumeLocation + 1);
|
| + return ufc->resumeLocation + 1;
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to alter instruction pointer.
|
| +_LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
|
| + uintptr_t new_value) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0lX)\n",
|
| + context, new_value);
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + ufc->resumeLocation = new_value - 1;
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 to find the start of the
|
| +/// function.
|
| +_LIBUNWIND_EXPORT uintptr_t
|
| +_Unwind_GetRegionStart(struct _Unwind_Context *context) {
|
| + // Not supported or needed for sjlj based unwinding
|
| + (void)context;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p)\n", context);
|
| + return 0;
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler during phase 2 if a foreign exception
|
| +/// is caught.
|
| +_LIBUNWIND_EXPORT void
|
| +_Unwind_DeleteException(struct _Unwind_Exception *exception_object) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)\n",
|
| + exception_object);
|
| + if (exception_object->exception_cleanup != NULL)
|
| + (*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT,
|
| + exception_object);
|
| +}
|
| +
|
| +
|
| +
|
| +/// 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) {
|
| + // Not supported or needed for sjlj based unwinding
|
| + (void)context;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetDataRelBase(context=%p)\n", context);
|
| + _LIBUNWIND_ABORT("_Unwind_GetDataRelBase() not implemented");
|
| +}
|
| +
|
| +
|
| +/// 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) {
|
| + // Not supported or needed for sjlj based unwinding
|
| + (void)context;
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetTextRelBase(context=%p)\n", context);
|
| + _LIBUNWIND_ABORT("_Unwind_GetTextRelBase() not implemented");
|
| +}
|
| +
|
| +
|
| +/// Called by personality handler to get "Call Frame Area" for current frame.
|
| +_LIBUNWIND_EXPORT uintptr_t _Unwind_GetCFA(struct _Unwind_Context *context) {
|
| + _LIBUNWIND_TRACE_API("_Unwind_GetCFA(context=%p)\n", context);
|
| + if (context != NULL) {
|
| + _Unwind_FunctionContext_t ufc = (_Unwind_FunctionContext_t) context;
|
| + // Setjmp/longjmp based exceptions don't have a true CFA.
|
| + // Instead, the SP in the jmpbuf is the closest approximation.
|
| + return (uintptr_t) ufc->jbuf[2];
|
| + }
|
| + return 0;
|
| +}
|
| +
|
| +#endif // _LIBUNWIND_BUILD_SJLJ_APIS
|
|
|
| Property changes on: third_party/libc++abi/src/Unwind/Unwind-sjlj.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|