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 |