| //===------------------------- UnwindLevel1.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 C++ ABI Exception Handling Level 1 as documented at: |
| // http://mentorembedded.github.io/cxx-abi/abi-eh.html |
| // using libunwind |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // 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> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include "libunwind.h" |
| #include "unwind.h" |
| #include "config.h" |
| |
| #if !defined(_LIBUNWIND_ARM_EHABI) && !defined(__USING_SJLJ_EXCEPTIONS__) |
| |
| static _Unwind_Reason_Code |
| unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) { |
| unw_init_local(cursor, uc); |
| |
| // Walk each frame looking for a place to stop. |
| bool handlerNotFound = true; |
| while (handlerNotFound) { |
| // Ask libunwind to get next frame (skip over first which is |
| // _Unwind_RaiseException). |
| int stepResult = unw_step(cursor); |
| if (stepResult == 0) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached " |
| "bottom => _URC_END_OF_STACK", |
| (void *)exception_object); |
| return _URC_END_OF_STACK; |
| } else if (stepResult < 0) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => " |
| "_URC_FATAL_PHASE1_ERROR", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE1_ERROR; |
| } |
| |
| // See if frame has code to run (has personality routine). |
| unw_proc_info_t frameInfo; |
| unw_word_t sp; |
| if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info " |
| "failed => _URC_FATAL_PHASE1_ERROR", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE1_ERROR; |
| } |
| |
| // When tracing, print state information. |
| if (_LIBUNWIND_TRACING_UNWINDING) { |
| char functionBuf[512]; |
| const char *functionName = functionBuf; |
| unw_word_t offset; |
| if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), |
| &offset) != UNW_ESUCCESS) || |
| (frameInfo.start_ip + offset > frameInfo.end_ip)) |
| functionName = ".anonymous."; |
| unw_word_t pc; |
| unw_get_reg(cursor, UNW_REG_IP, &pc); |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase1(ex_ojb=%p): pc=0x%" PRIxPTR ", start_ip=0x%" PRIxPTR |
| ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR "", |
| (void *)exception_object, pc, frameInfo.start_ip, functionName, |
| frameInfo.lsda, frameInfo.handler); |
| } |
| |
| // If there is a personality routine, ask it if it will want to stop at |
| // this frame. |
| if (frameInfo.handler != 0) { |
| __personality_routine p = |
| (__personality_routine)(uintptr_t)(frameInfo.handler); |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase1(ex_ojb=%p): calling personality function %p", |
| (void *)exception_object, (void *)(uintptr_t)p); |
| _Unwind_Reason_Code personalityResult = |
| (*p)(1, _UA_SEARCH_PHASE, exception_object->exception_class, |
| exception_object, (struct _Unwind_Context *)(cursor)); |
| switch (personalityResult) { |
| case _URC_HANDLER_FOUND: |
| // found a catch clause or locals that need destructing in this frame |
| // stop search and remember stack pointer at the frame |
| handlerNotFound = false; |
| unw_get_reg(cursor, UNW_REG_SP, &sp); |
| exception_object->private_2 = (uintptr_t)sp; |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND", |
| (void *)exception_object); |
| return _URC_NO_REASON; |
| |
| case _URC_CONTINUE_UNWIND: |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND", |
| (void *)exception_object); |
| // continue unwinding |
| break; |
| |
| default: |
| // something went wrong |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE1_ERROR; |
| } |
| } |
| } |
| return _URC_NO_REASON; |
| } |
| |
| |
| static _Unwind_Reason_Code |
| unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) { |
| unw_init_local(cursor, uc); |
| |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)", |
| (void *)exception_object); |
| |
| // Walk each frame until we reach where search phase said to stop. |
| while (true) { |
| |
| // Ask libunwind to get next frame (skip over first which is |
| // _Unwind_RaiseException). |
| int stepResult = unw_step(cursor); |
| if (stepResult == 0) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached " |
| "bottom => _URC_END_OF_STACK", |
| (void *)exception_object); |
| return _URC_END_OF_STACK; |
| } else if (stepResult < 0) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => " |
| "_URC_FATAL_PHASE1_ERROR", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| |
| // Get info about this frame. |
| unw_word_t sp; |
| unw_proc_info_t frameInfo; |
| unw_get_reg(cursor, UNW_REG_SP, &sp); |
| if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info " |
| "failed => _URC_FATAL_PHASE1_ERROR", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| |
| // When tracing, print state information. |
| if (_LIBUNWIND_TRACING_UNWINDING) { |
| char functionBuf[512]; |
| const char *functionName = functionBuf; |
| unw_word_t offset; |
| if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), |
| &offset) != UNW_ESUCCESS) || |
| (frameInfo.start_ip + offset > frameInfo.end_ip)) |
| functionName = ".anonymous."; |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): start_ip=0x%" PRIxPTR |
| ", func=%s, sp=0x%" PRIxPTR ", lsda=0x%" PRIxPTR |
| ", personality=0x%" PRIxPTR, |
| (void *)exception_object, frameInfo.start_ip, |
| functionName, sp, frameInfo.lsda, |
| frameInfo.handler); |
| } |
| |
| // If there is a personality routine, tell it we are unwinding. |
| if (frameInfo.handler != 0) { |
| __personality_routine p = |
| (__personality_routine)(uintptr_t)(frameInfo.handler); |
| _Unwind_Action action = _UA_CLEANUP_PHASE; |
| if (sp == exception_object->private_2) { |
| // Tell personality this was the frame it marked in phase 1. |
| action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME); |
| } |
| _Unwind_Reason_Code personalityResult = |
| (*p)(1, action, exception_object->exception_class, exception_object, |
| (struct _Unwind_Context *)(cursor)); |
| switch (personalityResult) { |
| case _URC_CONTINUE_UNWIND: |
| // Continue unwinding |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND", |
| (void *)exception_object); |
| if (sp == 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 in phase2 it did not stop here"); |
| } |
| break; |
| case _URC_INSTALL_CONTEXT: |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT", |
| (void *)exception_object); |
| // Personality routine says to transfer control to landing pad. |
| // We may get control back if landing pad calls _Unwind_Resume(). |
| if (_LIBUNWIND_TRACING_UNWINDING) { |
| unw_word_t pc; |
| unw_get_reg(cursor, UNW_REG_IP, &pc); |
| unw_get_reg(cursor, UNW_REG_SP, &sp); |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering " |
| "user code with ip=0x%" PRIxPTR |
| ", sp=0x%" PRIxPTR, |
| (void *)exception_object, pc, sp); |
| } |
| unw_resume(cursor); |
| // unw_resume() only returns if there was an error. |
| return _URC_FATAL_PHASE2_ERROR; |
| default: |
| // Personality routine returned an unknown result code. |
| _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d", |
| personalityResult); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| } |
| } |
| |
| // 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(unw_context_t *uc, unw_cursor_t *cursor, |
| _Unwind_Exception *exception_object, |
| _Unwind_Stop_Fn stop, void *stop_parameter) { |
| unw_init_local(cursor, uc); |
| |
| // Walk each frame until we reach where search phase said to stop |
| while (unw_step(cursor) > 0) { |
| |
| // Update info about this frame. |
| unw_proc_info_t frameInfo; |
| if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step " |
| "failed => _URC_END_OF_STACK", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| |
| // When tracing, print state information. |
| if (_LIBUNWIND_TRACING_UNWINDING) { |
| char functionBuf[512]; |
| const char *functionName = functionBuf; |
| unw_word_t offset; |
| if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), |
| &offset) != UNW_ESUCCESS) || |
| (frameInfo.start_ip + offset > frameInfo.end_ip)) |
| functionName = ".anonymous."; |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR |
| ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR, |
| (void *)exception_object, frameInfo.start_ip, functionName, |
| frameInfo.lsda, frameInfo.handler); |
| } |
| |
| // 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 *)(cursor), stop_parameter); |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2_forced(ex_ojb=%p): stop function returned %d", |
| (void *)exception_object, stopResult); |
| if (stopResult != _URC_NO_REASON) { |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2_forced(ex_ojb=%p): stopped by stop function", |
| (void *)exception_object); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| |
| // If there is a personality routine, tell it we are unwinding. |
| if (frameInfo.handler != 0) { |
| __personality_routine p = |
| (__personality_routine)(long)(frameInfo.handler); |
| _LIBUNWIND_TRACE_UNWINDING( |
| "unwind_phase2_forced(ex_ojb=%p): calling personality function %p", |
| (void *)exception_object, (void *)(uintptr_t)p); |
| _Unwind_Reason_Code personalityResult = |
| (*p)(1, action, exception_object->exception_class, exception_object, |
| (struct _Unwind_Context *)(cursor)); |
| switch (personalityResult) { |
| case _URC_CONTINUE_UNWIND: |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
| "personality returned " |
| "_URC_CONTINUE_UNWIND", |
| (void *)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", |
| (void *)exception_object); |
| // We may get control back if landing pad calls _Unwind_Resume(). |
| unw_resume(cursor); |
| break; |
| default: |
| // Personality routine returned an unknown result code. |
| _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
| "personality returned %d, " |
| "_URC_FATAL_PHASE2_ERROR", |
| (void *)exception_object, personalityResult); |
| return _URC_FATAL_PHASE2_ERROR; |
| } |
| } |
| } |
| |
| // 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", |
| (void *)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 *)(cursor), 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_RaiseException(_Unwind_Exception *exception_object) { |
| _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)", |
| (void *)exception_object); |
| unw_context_t uc; |
| unw_cursor_t cursor; |
| unw_getcontext(&uc); |
| |
| // 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(&uc, &cursor, exception_object); |
| if (phase1 != _URC_NO_REASON) |
| return phase1; |
| |
| // phase 2: the clean up phase |
| return unwind_phase2(&uc, &cursor, 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. |
| /// |
| /// Note: re-throwing an exception (as opposed to continuing the unwind) |
| /// is implemented by having the code call __cxa_rethrow() which |
| /// in turn calls _Unwind_Resume_or_Rethrow(). |
| _LIBUNWIND_EXPORT void |
| _Unwind_Resume(_Unwind_Exception *exception_object) { |
| _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object); |
| unw_context_t uc; |
| unw_cursor_t cursor; |
| unw_getcontext(&uc); |
| |
| if (exception_object->private_1 != 0) |
| unwind_phase2_forced(&uc, &cursor, exception_object, |
| (_Unwind_Stop_Fn) exception_object->private_1, |
| (void *)exception_object->private_2); |
| else |
| unwind_phase2(&uc, &cursor, exception_object); |
| |
| // Clients assume _Unwind_Resume() does not return, so all we can do is abort. |
| _LIBUNWIND_ABORT("_Unwind_Resume() can't return"); |
| } |
| |
| |
| |
| /// Not used by C++. |
| /// Unwinds stack, calling "stop" function at each frame. |
| /// Could be used to implement longjmp(). |
| _LIBUNWIND_EXPORT _Unwind_Reason_Code |
| _Unwind_ForcedUnwind(_Unwind_Exception *exception_object, |
| _Unwind_Stop_Fn stop, void *stop_parameter) { |
| _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)", |
| (void *)exception_object, (void *)(uintptr_t)stop); |
| unw_context_t uc; |
| unw_cursor_t cursor; |
| unw_getcontext(&uc); |
| |
| // Mark that this is a forced unwind, so _Unwind_Resume() can do |
| // the right thing. |
| exception_object->private_1 = (uintptr_t) stop; |
| exception_object->private_2 = (uintptr_t) stop_parameter; |
| |
| // do it |
| return unwind_phase2_forced(&uc, &cursor, exception_object, stop, stop_parameter); |
| } |
| |
| |
| /// Called by personality handler during phase 2 to get LSDA for current frame. |
| _LIBUNWIND_EXPORT uintptr_t |
| _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) { |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_proc_info_t frameInfo; |
| uintptr_t result = 0; |
| if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS) |
| result = (uintptr_t)frameInfo.lsda; |
| _LIBUNWIND_TRACE_API( |
| "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR, |
| (void *)context, result); |
| if (result != 0) { |
| if (*((uint8_t *)result) != 0xFF) |
| _LIBUNWIND_DEBUG_LOG("lsda at 0x%" PRIxPTR " does not start with 0xFF", |
| result); |
| } |
| return result; |
| } |
| |
| |
| /// Called by personality handler during phase 2 to find the start of the |
| /// function. |
| _LIBUNWIND_EXPORT uintptr_t |
| _Unwind_GetRegionStart(struct _Unwind_Context *context) { |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_proc_info_t frameInfo; |
| uintptr_t result = 0; |
| if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS) |
| result = (uintptr_t)frameInfo.start_ip; |
| _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR, |
| (void *)context, result); |
| return result; |
| } |
| |
| |
| /// Called by personality handler during phase 2 if a foreign exception |
| // is caught. |
| _LIBUNWIND_EXPORT void |
| _Unwind_DeleteException(_Unwind_Exception *exception_object) { |
| _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)", |
| (void *)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 register values. |
| _LIBUNWIND_EXPORT uintptr_t |
| _Unwind_GetGR(struct _Unwind_Context *context, int index) { |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_word_t result; |
| unw_get_reg(cursor, index, &result); |
| _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIxPTR, |
| (void *)context, index, result); |
| return (uintptr_t)result; |
| } |
| |
| /// Called by personality handler during phase 2 to alter register values. |
| _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" PRIxPTR |
| ")", |
| (void *)context, index, value); |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_set_reg(cursor, index, value); |
| } |
| |
| /// Called by personality handler during phase 2 to get instruction pointer. |
| _LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) { |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_word_t result; |
| unw_get_reg(cursor, UNW_REG_IP, &result); |
| _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIxPTR, |
| (void *)context, result); |
| return (uintptr_t)result; |
| } |
| |
| /// Called by personality handler during phase 2 to alter instruction pointer, |
| /// such as setting where the landing pad is, so _Unwind_Resume() will |
| /// start executing in the landing pad. |
| _LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context, |
| uintptr_t value) { |
| _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIxPTR ")", |
| (void *)context, value); |
| unw_cursor_t *cursor = (unw_cursor_t *)context; |
| unw_set_reg(cursor, UNW_REG_IP, value); |
| } |
| |
| #endif // !defined(_LIBUNWIND_ARM_EHABI) && !defined(__USING_SJLJ_EXCEPTIONS__) |
