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-rw-r--r--src/UnwindCursor.hpp1338
1 files changed, 1338 insertions, 0 deletions
diff --git a/src/UnwindCursor.hpp b/src/UnwindCursor.hpp
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+++ b/src/UnwindCursor.hpp
@@ -0,0 +1,1338 @@
+//===------------------------- UnwindCursor.hpp ---------------------------===//
+//
+// 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.
+//
+//
+// C++ interface to lower levels of libuwind
+//===----------------------------------------------------------------------===//
+
+#ifndef __UNWINDCURSOR_HPP__
+#define __UNWINDCURSOR_HPP__
+
+#include <algorithm>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unwind.h>
+
+#ifdef __APPLE__
+ #include <mach-o/dyld.h>
+#endif
+
+#include "config.h"
+
+#include "AddressSpace.hpp"
+#include "CompactUnwinder.hpp"
+#include "config.h"
+#include "DwarfInstructions.hpp"
+#include "EHHeaderParser.hpp"
+#include "libunwind.h"
+#include "Registers.hpp"
+#include "Unwind-EHABI.h"
+
+namespace libunwind {
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+/// Cache of recently found FDEs.
+template <typename A>
+class _LIBUNWIND_HIDDEN DwarfFDECache {
+ typedef typename A::pint_t pint_t;
+public:
+ static pint_t findFDE(pint_t mh, pint_t pc);
+ static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
+ static void removeAllIn(pint_t mh);
+ static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
+ unw_word_t ip_end,
+ unw_word_t fde, unw_word_t mh));
+
+private:
+
+ struct entry {
+ pint_t mh;
+ pint_t ip_start;
+ pint_t ip_end;
+ pint_t fde;
+ };
+
+ // These fields are all static to avoid needing an initializer.
+ // There is only one instance of this class per process.
+ static pthread_rwlock_t _lock;
+#ifdef __APPLE__
+ static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
+ static bool _registeredForDyldUnloads;
+#endif
+ // Can't use std::vector<> here because this code is below libc++.
+ static entry *_buffer;
+ static entry *_bufferUsed;
+ static entry *_bufferEnd;
+ static entry _initialBuffer[64];
+};
+
+template <typename A>
+typename DwarfFDECache<A>::entry *
+DwarfFDECache<A>::_buffer = _initialBuffer;
+
+template <typename A>
+typename DwarfFDECache<A>::entry *
+DwarfFDECache<A>::_bufferUsed = _initialBuffer;
+
+template <typename A>
+typename DwarfFDECache<A>::entry *
+DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
+
+template <typename A>
+typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
+
+template <typename A>
+pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER;
+
+#ifdef __APPLE__
+template <typename A>
+bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
+#endif
+
+template <typename A>
+typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
+ pint_t result = 0;
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_rdlock(&_lock));
+ for (entry *p = _buffer; p < _bufferUsed; ++p) {
+ if ((mh == p->mh) || (mh == 0)) {
+ if ((p->ip_start <= pc) && (pc < p->ip_end)) {
+ result = p->fde;
+ break;
+ }
+ }
+ }
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock));
+ return result;
+}
+
+template <typename A>
+void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
+ pint_t fde) {
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock));
+ if (_bufferUsed >= _bufferEnd) {
+ size_t oldSize = (size_t)(_bufferEnd - _buffer);
+ size_t newSize = oldSize * 4;
+ // Can't use operator new (we are below it).
+ entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
+ memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
+ if (_buffer != _initialBuffer)
+ free(_buffer);
+ _buffer = newBuffer;
+ _bufferUsed = &newBuffer[oldSize];
+ _bufferEnd = &newBuffer[newSize];
+ }
+ _bufferUsed->mh = mh;
+ _bufferUsed->ip_start = ip_start;
+ _bufferUsed->ip_end = ip_end;
+ _bufferUsed->fde = fde;
+ ++_bufferUsed;
+#ifdef __APPLE__
+ if (!_registeredForDyldUnloads) {
+ _dyld_register_func_for_remove_image(&dyldUnloadHook);
+ _registeredForDyldUnloads = true;
+ }
+#endif
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock));
+}
+
+template <typename A>
+void DwarfFDECache<A>::removeAllIn(pint_t mh) {
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock));
+ entry *d = _buffer;
+ for (const entry *s = _buffer; s < _bufferUsed; ++s) {
+ if (s->mh != mh) {
+ if (d != s)
+ *d = *s;
+ ++d;
+ }
+ }
+ _bufferUsed = d;
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock));
+}
+
+#ifdef __APPLE__
+template <typename A>
+void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
+ removeAllIn((pint_t) mh);
+}
+#endif
+
+template <typename A>
+void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
+ unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_wrlock(&_lock));
+ for (entry *p = _buffer; p < _bufferUsed; ++p) {
+ (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
+ }
+ _LIBUNWIND_LOG_NON_ZERO(::pthread_rwlock_unlock(&_lock));
+}
+#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+
+#define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
+
+#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+template <typename A> class UnwindSectionHeader {
+public:
+ UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t version() const {
+ return _addressSpace.get32(_addr +
+ offsetof(unwind_info_section_header, version));
+ }
+ uint32_t commonEncodingsArraySectionOffset() const {
+ return _addressSpace.get32(_addr +
+ offsetof(unwind_info_section_header,
+ commonEncodingsArraySectionOffset));
+ }
+ uint32_t commonEncodingsArrayCount() const {
+ return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
+ commonEncodingsArrayCount));
+ }
+ uint32_t personalityArraySectionOffset() const {
+ return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
+ personalityArraySectionOffset));
+ }
+ uint32_t personalityArrayCount() const {
+ return _addressSpace.get32(
+ _addr + offsetof(unwind_info_section_header, personalityArrayCount));
+ }
+ uint32_t indexSectionOffset() const {
+ return _addressSpace.get32(
+ _addr + offsetof(unwind_info_section_header, indexSectionOffset));
+ }
+ uint32_t indexCount() const {
+ return _addressSpace.get32(
+ _addr + offsetof(unwind_info_section_header, indexCount));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionIndexArray {
+public:
+ UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t functionOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
+ functionOffset));
+ }
+ uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
+ secondLevelPagesSectionOffset));
+ }
+ uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
+ lsdaIndexArraySectionOffset));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionRegularPageHeader {
+public:
+ UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t kind() const {
+ return _addressSpace.get32(
+ _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
+ }
+ uint16_t entryPageOffset() const {
+ return _addressSpace.get16(
+ _addr + offsetof(unwind_info_regular_second_level_page_header,
+ entryPageOffset));
+ }
+ uint16_t entryCount() const {
+ return _addressSpace.get16(
+ _addr +
+ offsetof(unwind_info_regular_second_level_page_header, entryCount));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionRegularArray {
+public:
+ UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t functionOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
+ functionOffset));
+ }
+ uint32_t encoding(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr +
+ arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionCompressedPageHeader {
+public:
+ UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t kind() const {
+ return _addressSpace.get32(
+ _addr +
+ offsetof(unwind_info_compressed_second_level_page_header, kind));
+ }
+ uint16_t entryPageOffset() const {
+ return _addressSpace.get16(
+ _addr + offsetof(unwind_info_compressed_second_level_page_header,
+ entryPageOffset));
+ }
+ uint16_t entryCount() const {
+ return _addressSpace.get16(
+ _addr +
+ offsetof(unwind_info_compressed_second_level_page_header, entryCount));
+ }
+ uint16_t encodingsPageOffset() const {
+ return _addressSpace.get16(
+ _addr + offsetof(unwind_info_compressed_second_level_page_header,
+ encodingsPageOffset));
+ }
+ uint16_t encodingsCount() const {
+ return _addressSpace.get16(
+ _addr + offsetof(unwind_info_compressed_second_level_page_header,
+ encodingsCount));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionCompressedArray {
+public:
+ UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t functionOffset(uint32_t index) const {
+ return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
+ _addressSpace.get32(_addr + index * sizeof(uint32_t)));
+ }
+ uint16_t encodingIndex(uint32_t index) const {
+ return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
+ _addressSpace.get32(_addr + index * sizeof(uint32_t)));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+
+template <typename A> class UnwindSectionLsdaArray {
+public:
+ UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
+ : _addressSpace(addressSpace), _addr(addr) {}
+
+ uint32_t functionOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
+ index, functionOffset));
+ }
+ uint32_t lsdaOffset(uint32_t index) const {
+ return _addressSpace.get32(
+ _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
+ index, lsdaOffset));
+ }
+
+private:
+ A &_addressSpace;
+ typename A::pint_t _addr;
+};
+#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+
+class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
+public:
+ // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
+ // This avoids an unnecessary dependency to libc++abi.
+ void operator delete(void *, size_t) {}
+
+ virtual ~AbstractUnwindCursor() {}
+ virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
+ virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
+ virtual void setReg(int, unw_word_t) {
+ _LIBUNWIND_ABORT("setReg not implemented");
+ }
+ virtual bool validFloatReg(int) {
+ _LIBUNWIND_ABORT("validFloatReg not implemented");
+ }
+ virtual unw_fpreg_t getFloatReg(int) {
+ _LIBUNWIND_ABORT("getFloatReg not implemented");
+ }
+ virtual void setFloatReg(int, unw_fpreg_t) {
+ _LIBUNWIND_ABORT("setFloatReg not implemented");
+ }
+ virtual int step() { _LIBUNWIND_ABORT("step not implemented"); }
+ virtual void getInfo(unw_proc_info_t *) {
+ _LIBUNWIND_ABORT("getInfo not implemented");
+ }
+ virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
+ virtual bool isSignalFrame() {
+ _LIBUNWIND_ABORT("isSignalFrame not implemented");
+ }
+ virtual bool getFunctionName(char *, size_t, unw_word_t *) {
+ _LIBUNWIND_ABORT("getFunctionName not implemented");
+ }
+ virtual void setInfoBasedOnIPRegister(bool = false) {
+ _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
+ }
+ virtual const char *getRegisterName(int) {
+ _LIBUNWIND_ABORT("getRegisterName not implemented");
+ }
+#ifdef __arm__
+ virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
+#endif
+};
+
+/// UnwindCursor contains all state (including all register values) during
+/// an unwind. This is normally stack allocated inside a unw_cursor_t.
+template <typename A, typename R>
+class UnwindCursor : public AbstractUnwindCursor{
+ typedef typename A::pint_t pint_t;
+public:
+ UnwindCursor(unw_context_t *context, A &as);
+ UnwindCursor(A &as, void *threadArg);
+ virtual ~UnwindCursor() {}
+ virtual bool validReg(int);
+ virtual unw_word_t getReg(int);
+ virtual void setReg(int, unw_word_t);
+ virtual bool validFloatReg(int);
+ virtual unw_fpreg_t getFloatReg(int);
+ virtual void setFloatReg(int, unw_fpreg_t);
+ virtual int step();
+ virtual void getInfo(unw_proc_info_t *);
+ virtual void jumpto();
+ virtual bool isSignalFrame();
+ virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
+ virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
+ virtual const char *getRegisterName(int num);
+#ifdef __arm__
+ virtual void saveVFPAsX();
+#endif
+
+private:
+
+#if _LIBUNWIND_ARM_EHABI
+ bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections &sects);
+
+ int stepWithEHABI() {
+ size_t len = 0;
+ size_t off = 0;
+ // FIXME: Calling decode_eht_entry() here is violating the libunwind
+ // abstraction layer.
+ const uint32_t *ehtp =
+ decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
+ &off, &len);
+ if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
+ _URC_CONTINUE_UNWIND)
+ return UNW_STEP_END;
+ return UNW_STEP_SUCCESS;
+ }
+#endif
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections &sects,
+ uint32_t fdeSectionOffsetHint=0);
+ int stepWithDwarfFDE() {
+ return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace,
+ (pint_t)this->getReg(UNW_REG_IP),
+ (pint_t)_info.unwind_info,
+ _registers);
+ }
+#endif
+
+#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+ bool getInfoFromCompactEncodingSection(pint_t pc,
+ const UnwindInfoSections &sects);
+ int stepWithCompactEncoding() {
+ #if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ if ( compactSaysUseDwarf() )
+ return stepWithDwarfFDE();
+ #endif
+ R dummy;
+ return stepWithCompactEncoding(dummy);
+ }
+
+ int stepWithCompactEncoding(Registers_x86_64 &) {
+ return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
+ _info.format, _info.start_ip, _addressSpace, _registers);
+ }
+
+ int stepWithCompactEncoding(Registers_x86 &) {
+ return CompactUnwinder_x86<A>::stepWithCompactEncoding(
+ _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
+ }
+
+ int stepWithCompactEncoding(Registers_ppc &) {
+ return UNW_EINVAL;
+ }
+
+ int stepWithCompactEncoding(Registers_arm64 &) {
+ return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
+ _info.format, _info.start_ip, _addressSpace, _registers);
+ }
+
+ bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
+ R dummy;
+ return compactSaysUseDwarf(dummy, offset);
+ }
+
+ bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
+ if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
+ if (offset)
+ *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
+ return true;
+ }
+ return false;
+ }
+
+ bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
+ if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
+ if (offset)
+ *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
+ return true;
+ }
+ return false;
+ }
+
+ bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
+ return true;
+ }
+
+ bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
+ if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
+ if (offset)
+ *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
+ return true;
+ }
+ return false;
+ }
+#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ compact_unwind_encoding_t dwarfEncoding() const {
+ R dummy;
+ return dwarfEncoding(dummy);
+ }
+
+ compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
+ return UNWIND_X86_64_MODE_DWARF;
+ }
+
+ compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
+ return UNWIND_X86_MODE_DWARF;
+ }
+
+ compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
+ return 0;
+ }
+
+ compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
+ return UNWIND_ARM64_MODE_DWARF;
+ }
+
+ compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
+ return 0;
+ }
+#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+
+ A &_addressSpace;
+ R _registers;
+ unw_proc_info_t _info;
+ bool _unwindInfoMissing;
+ bool _isSignalFrame;
+};
+
+
+template <typename A, typename R>
+UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
+ : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
+ _isSignalFrame(false) {
+ static_assert(sizeof(UnwindCursor<A, R>) < sizeof(unw_cursor_t),
+ "UnwindCursor<> does not fit in unw_cursor_t");
+ memset(&_info, 0, sizeof(_info));
+}
+
+template <typename A, typename R>
+UnwindCursor<A, R>::UnwindCursor(A &as, void *)
+ : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
+ memset(&_info, 0, sizeof(_info));
+ // FIXME
+ // fill in _registers from thread arg
+}
+
+
+template <typename A, typename R>
+bool UnwindCursor<A, R>::validReg(int regNum) {
+ return _registers.validRegister(regNum);
+}
+
+template <typename A, typename R>
+unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
+ return _registers.getRegister(regNum);
+}
+
+template <typename A, typename R>
+void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
+ _registers.setRegister(regNum, (typename A::pint_t)value);
+}
+
+template <typename A, typename R>
+bool UnwindCursor<A, R>::validFloatReg(int regNum) {
+ return _registers.validFloatRegister(regNum);
+}
+
+template <typename A, typename R>
+unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
+ return _registers.getFloatRegister(regNum);
+}
+
+template <typename A, typename R>
+void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
+ _registers.setFloatRegister(regNum, value);
+}
+
+template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
+ _registers.jumpto();
+}
+
+#ifdef __arm__
+template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
+ _registers.saveVFPAsX();
+}
+#endif
+
+template <typename A, typename R>
+const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
+ return _registers.getRegisterName(regNum);
+}
+
+template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
+ return _isSignalFrame;
+}
+
+#if _LIBUNWIND_ARM_EHABI
+struct EHABIIndexEntry {
+ uint32_t functionOffset;
+ uint32_t data;
+};
+
+template<typename A>
+struct EHABISectionIterator {
+ typedef EHABISectionIterator _Self;
+
+ typedef std::random_access_iterator_tag iterator_category;
+ typedef typename A::pint_t value_type;
+ typedef typename A::pint_t* pointer;
+ typedef typename A::pint_t& reference;
+ typedef size_t size_type;
+ typedef size_t difference_type;
+
+ static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
+ return _Self(addressSpace, sects, 0);
+ }
+ static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
+ return _Self(addressSpace, sects, sects.arm_section_length);
+ }
+
+ EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
+ : _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
+
+ _Self& operator++() { ++_i; return *this; }
+ _Self& operator+=(size_t a) { _i += a; return *this; }
+ _Self& operator--() { assert(_i > 0); --_i; return *this; }
+ _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
+
+ _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
+ _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
+
+ size_t operator-(const _Self& other) { return _i - other._i; }
+
+ bool operator==(const _Self& other) const {
+ assert(_addressSpace == other._addressSpace);
+ assert(_sects == other._sects);
+ return _i == other._i;
+ }
+
+ typename A::pint_t operator*() const { return functionAddress(); }
+
+ typename A::pint_t functionAddress() const {
+ typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
+ EHABIIndexEntry, _i, functionOffset);
+ return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
+ }
+
+ typename A::pint_t dataAddress() {
+ typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
+ EHABIIndexEntry, _i, data);
+ return indexAddr;
+ }
+
+ private:
+ size_t _i;
+ A* _addressSpace;
+ const UnwindInfoSections* _sects;
+};
+
+template <typename A, typename R>
+bool UnwindCursor<A, R>::getInfoFromEHABISection(
+ pint_t pc,
+ const UnwindInfoSections &sects) {
+ EHABISectionIterator<A> begin =
+ EHABISectionIterator<A>::begin(_addressSpace, sects);
+ EHABISectionIterator<A> end =
+ EHABISectionIterator<A>::end(_addressSpace, sects);
+
+ EHABISectionIterator<A> itNextPC = std::upper_bound(begin, end, pc);
+ if (itNextPC == begin || itNextPC == end)
+ return false;
+ EHABISectionIterator<A> itThisPC = itNextPC - 1;
+
+ pint_t thisPC = itThisPC.functionAddress();
+ pint_t nextPC = itNextPC.functionAddress();
+ pint_t indexDataAddr = itThisPC.dataAddress();
+
+ if (indexDataAddr == 0)
+ return false;
+
+ uint32_t indexData = _addressSpace.get32(indexDataAddr);
+ if (indexData == UNW_EXIDX_CANTUNWIND)
+ return false;
+
+ // If the high bit is set, the exception handling table entry is inline inside
+ // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
+ // the table points at an offset in the exception handling table (section 5 EHABI).
+ pint_t exceptionTableAddr;
+ uint32_t exceptionTableData;
+ bool isSingleWordEHT;
+ if (indexData & 0x80000000) {
+ exceptionTableAddr = indexDataAddr;
+ // TODO(ajwong): Should this data be 0?
+ exceptionTableData = indexData;
+ isSingleWordEHT = true;
+ } else {
+ exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
+ exceptionTableData = _addressSpace.get32(exceptionTableAddr);
+ isSingleWordEHT = false;
+ }
+
+ // Now we know the 3 things:
+ // exceptionTableAddr -- exception handler table entry.
+ // exceptionTableData -- the data inside the first word of the eht entry.
+ // isSingleWordEHT -- whether the entry is in the index.
+ unw_word_t personalityRoutine = 0xbadf00d;
+ bool scope32 = false;
+ uintptr_t lsda;
+
+ // If the high bit in the exception handling table entry is set, the entry is
+ // in compact form (section 6.3 EHABI).
+ if (exceptionTableData & 0x80000000) {
+ // Grab the index of the personality routine from the compact form.
+ uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
+ uint32_t extraWords = 0;
+ switch (choice) {
+ case 0:
+ personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
+ extraWords = 0;
+ scope32 = false;
+ lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
+ break;
+ case 1:
+ personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
+ extraWords = (exceptionTableData & 0x00ff0000) >> 16;
+ scope32 = false;
+ lsda = exceptionTableAddr + (extraWords + 1) * 4;
+ break;
+ case 2:
+ personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
+ extraWords = (exceptionTableData & 0x00ff0000) >> 16;
+ scope32 = true;
+ lsda = exceptionTableAddr + (extraWords + 1) * 4;
+ break;
+ default:
+ _LIBUNWIND_ABORT("unknown personality routine");
+ return false;
+ }
+
+ if (isSingleWordEHT) {
+ if (extraWords != 0) {
+ _LIBUNWIND_ABORT("index inlined table detected but pr function "
+ "requires extra words");
+ return false;
+ }
+ }
+ } else {
+ pint_t personalityAddr =
+ exceptionTableAddr + signExtendPrel31(exceptionTableData);
+ personalityRoutine = personalityAddr;
+
+ // ARM EHABI # 6.2, # 9.2
+ //
+ // +---- ehtp
+ // v
+ // +--------------------------------------+
+ // | +--------+--------+--------+-------+ |
+ // | |0| prel31 to personalityRoutine | |
+ // | +--------+--------+--------+-------+ |
+ // | | N | unwind opcodes | | <-- UnwindData
+ // | +--------+--------+--------+-------+ |
+ // | | Word 2 unwind opcodes | |
+ // | +--------+--------+--------+-------+ |
+ // | ... |
+ // | +--------+--------+--------+-------+ |
+ // | | Word N unwind opcodes | |
+ // | +--------+--------+--------+-------+ |
+ // | | LSDA | | <-- lsda
+ // | | ... | |
+ // | +--------+--------+--------+-------+ |
+ // +--------------------------------------+
+
+ uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
+ uint32_t FirstDataWord = *UnwindData;
+ size_t N = ((FirstDataWord >> 24) & 0xff);
+ size_t NDataWords = N + 1;
+ lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
+ }
+
+ _info.start_ip = thisPC;
+ _info.end_ip = nextPC;
+ _info.handler = personalityRoutine;
+ _info.unwind_info = exceptionTableAddr;
+ _info.lsda = lsda;
+ // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
+ _info.flags = isSingleWordEHT ? 1 : 0 | scope32 ? 0x2 : 0; // Use enum?
+
+ return true;
+}
+#endif
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+template <typename A, typename R>
+bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
+ const UnwindInfoSections &sects,
+ uint32_t fdeSectionOffsetHint) {
+ typename CFI_Parser<A>::FDE_Info fdeInfo;
+ typename CFI_Parser<A>::CIE_Info cieInfo;
+ bool foundFDE = false;
+ bool foundInCache = false;
+ // If compact encoding table gave offset into dwarf section, go directly there
+ if (fdeSectionOffsetHint != 0) {
+ foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
+ (uint32_t)sects.dwarf_section_length,
+ sects.dwarf_section + fdeSectionOffsetHint,
+ &fdeInfo, &cieInfo);
+ }
+#if _LIBUNWIND_SUPPORT_DWARF_INDEX
+ if (!foundFDE && (sects.dwarf_index_section != 0)) {
+ foundFDE = EHHeaderParser<A>::findFDE(
+ _addressSpace, pc, sects.dwarf_index_section,
+ (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
+ }
+#endif
+ if (!foundFDE) {
+ // otherwise, search cache of previously found FDEs.
+ pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
+ if (cachedFDE != 0) {
+ foundFDE =
+ CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
+ (uint32_t)sects.dwarf_section_length,
+ cachedFDE, &fdeInfo, &cieInfo);
+ foundInCache = foundFDE;
+ }
+ }
+ if (!foundFDE) {
+ // Still not found, do full scan of __eh_frame section.
+ foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
+ (uint32_t)sects.dwarf_section_length, 0,
+ &fdeInfo, &cieInfo);
+ }
+ if (foundFDE) {
+ typename CFI_Parser<A>::PrologInfo prolog;
+ if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
+ &prolog)) {
+ // Save off parsed FDE info
+ _info.start_ip = fdeInfo.pcStart;
+ _info.end_ip = fdeInfo.pcEnd;
+ _info.lsda = fdeInfo.lsda;
+ _info.handler = cieInfo.personality;
+ _info.gp = prolog.spExtraArgSize;
+ _info.flags = 0;
+ _info.format = dwarfEncoding();
+ _info.unwind_info = fdeInfo.fdeStart;
+ _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength;
+ _info.extra = (unw_word_t) sects.dso_base;
+
+ // Add to cache (to make next lookup faster) if we had no hint
+ // and there was no index.
+ if (!foundInCache && (fdeSectionOffsetHint == 0)) {
+ #if _LIBUNWIND_SUPPORT_DWARF_INDEX
+ if (sects.dwarf_index_section == 0)
+ #endif
+ DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
+ fdeInfo.fdeStart);
+ }
+ return true;
+ }
+ }
+ //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX\n", (uint64_t)pc);
+ return false;
+}
+#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+
+#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+template <typename A, typename R>
+bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
+ const UnwindInfoSections &sects) {
+ const bool log = false;
+ if (log)
+ fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
+ (uint64_t)pc, (uint64_t)sects.dso_base);
+
+ const UnwindSectionHeader<A> sectionHeader(_addressSpace,
+ sects.compact_unwind_section);
+ if (sectionHeader.version() != UNWIND_SECTION_VERSION)
+ return false;
+
+ // do a binary search of top level index to find page with unwind info
+ pint_t targetFunctionOffset = pc - sects.dso_base;
+ const UnwindSectionIndexArray<A> topIndex(_addressSpace,
+ sects.compact_unwind_section
+ + sectionHeader.indexSectionOffset());
+ uint32_t low = 0;
+ uint32_t high = sectionHeader.indexCount();
+ uint32_t last = high - 1;
+ while (low < high) {
+ uint32_t mid = (low + high) / 2;
+ //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
+ //mid, low, high, topIndex.functionOffset(mid));
+ if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
+ if ((mid == last) ||
+ (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
+ low = mid;
+ break;
+ } else {
+ low = mid + 1;
+ }
+ } else {
+ high = mid;
+ }
+ }
+ const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
+ const uint32_t firstLevelNextPageFunctionOffset =
+ topIndex.functionOffset(low + 1);
+ const pint_t secondLevelAddr =
+ sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
+ const pint_t lsdaArrayStartAddr =
+ sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
+ const pint_t lsdaArrayEndAddr =
+ sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
+ if (log)
+ fprintf(stderr, "\tfirst level search for result index=%d "
+ "to secondLevelAddr=0x%llX\n",
+ low, (uint64_t) secondLevelAddr);
+ // do a binary search of second level page index
+ uint32_t encoding = 0;
+ pint_t funcStart = 0;
+ pint_t funcEnd = 0;
+ pint_t lsda = 0;
+ pint_t personality = 0;
+ uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
+ if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
+ // regular page
+ UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
+ secondLevelAddr);
+ UnwindSectionRegularArray<A> pageIndex(
+ _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
+ // binary search looks for entry with e where index[e].offset <= pc <
+ // index[e+1].offset
+ if (log)
+ fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
+ "regular page starting at secondLevelAddr=0x%llX\n",
+ (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
+ low = 0;
+ high = pageHeader.entryCount();
+ while (low < high) {
+ uint32_t mid = (low + high) / 2;
+ if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
+ if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
+ // at end of table
+ low = mid;
+ funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
+ break;
+ } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
+ // next is too big, so we found it
+ low = mid;
+ funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
+ break;
+ } else {
+ low = mid + 1;
+ }
+ } else {
+ high = mid;
+ }
+ }
+ encoding = pageIndex.encoding(low);
+ funcStart = pageIndex.functionOffset(low) + sects.dso_base;
+ if (pc < funcStart) {
+ if (log)
+ fprintf(
+ stderr,
+ "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
+ (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
+ return false;
+ }
+ if (pc > funcEnd) {
+ if (log)
+ fprintf(
+ stderr,
+ "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
+ (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
+ return false;
+ }
+ } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
+ // compressed page
+ UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
+ secondLevelAddr);
+ UnwindSectionCompressedArray<A> pageIndex(
+ _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
+ const uint32_t targetFunctionPageOffset =
+ (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
+ // binary search looks for entry with e where index[e].offset <= pc <
+ // index[e+1].offset
+ if (log)
+ fprintf(stderr, "\tbinary search of compressed page starting at "
+ "secondLevelAddr=0x%llX\n",
+ (uint64_t) secondLevelAddr);
+ low = 0;
+ last = pageHeader.entryCount() - 1;
+ high = pageHeader.entryCount();
+ while (low < high) {
+ uint32_t mid = (low + high) / 2;
+ if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
+ if ((mid == last) ||
+ (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
+ low = mid;
+ break;
+ } else {
+ low = mid + 1;
+ }
+ } else {
+ high = mid;
+ }
+ }
+ funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
+ + sects.dso_base;
+ if (low < last)
+ funcEnd =
+ pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
+ + sects.dso_base;
+ else
+ funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
+ if (pc < funcStart) {
+ _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second "
+ "level compressed unwind table. funcStart=0x%llX\n",
+ (uint64_t) pc, (uint64_t) funcStart);
+ return false;
+ }
+ if (pc > funcEnd) {
+ _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX not in second "
+ "level compressed unwind table. funcEnd=0x%llX\n",
+ (uint64_t) pc, (uint64_t) funcEnd);
+ return false;
+ }
+ uint16_t encodingIndex = pageIndex.encodingIndex(low);
+ if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
+ // encoding is in common table in section header
+ encoding = _addressSpace.get32(
+ sects.compact_unwind_section +
+ sectionHeader.commonEncodingsArraySectionOffset() +
+ encodingIndex * sizeof(uint32_t));
+ } else {
+ // encoding is in page specific table
+ uint16_t pageEncodingIndex =
+ encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
+ encoding = _addressSpace.get32(secondLevelAddr +
+ pageHeader.encodingsPageOffset() +
+ pageEncodingIndex * sizeof(uint32_t));
+ }
+ } else {
+ _LIBUNWIND_DEBUG_LOG("malformed __unwind_info at 0x%0llX bad second "
+ "level page\n",
+ (uint64_t) sects.compact_unwind_section);
+ return false;
+ }
+
+ // look up LSDA, if encoding says function has one
+ if (encoding & UNWIND_HAS_LSDA) {
+ UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
+ uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
+ low = 0;
+ high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
+ sizeof(unwind_info_section_header_lsda_index_entry);
+ // binary search looks for entry with exact match for functionOffset
+ if (log)
+ fprintf(stderr,
+ "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
+ funcStartOffset);
+ while (low < high) {
+ uint32_t mid = (low + high) / 2;
+ if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
+ lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
+ break;
+ } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
+ low = mid + 1;
+ } else {
+ high = mid;
+ }
+ }
+ if (lsda == 0) {
+ _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
+ "pc=0x%0llX, but lsda table has no entry\n",
+ encoding, (uint64_t) pc);
+ return false;
+ }
+ }
+
+ // extact personality routine, if encoding says function has one
+ uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
+ (__builtin_ctz(UNWIND_PERSONALITY_MASK));
+ if (personalityIndex != 0) {
+ --personalityIndex; // change 1-based to zero-based index
+ if (personalityIndex > sectionHeader.personalityArrayCount()) {
+ _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
+ "but personality table has only %d entires\n",
+ encoding, personalityIndex,
+ sectionHeader.personalityArrayCount());
+ return false;
+ }
+ int32_t personalityDelta = (int32_t)_addressSpace.get32(
+ sects.compact_unwind_section +
+ sectionHeader.personalityArraySectionOffset() +
+ personalityIndex * sizeof(uint32_t));
+ pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
+ personality = _addressSpace.getP(personalityPointer);
+ if (log)
+ fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
+ "personalityDelta=0x%08X, personality=0x%08llX\n",
+ (uint64_t) pc, personalityDelta, (uint64_t) personality);
+ }
+
+ if (log)
+ fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
+ "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
+ (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
+ _info.start_ip = funcStart;
+ _info.end_ip = funcEnd;
+ _info.lsda = lsda;
+ _info.handler = personality;
+ _info.gp = 0;
+ _info.flags = 0;
+ _info.format = encoding;
+ _info.unwind_info = 0;
+ _info.unwind_info_size = 0;
+ _info.extra = sects.dso_base;
+ return true;
+}
+#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+
+
+template <typename A, typename R>
+void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
+ pint_t pc = (pint_t)this->getReg(UNW_REG_IP);
+#if _LIBUNWIND_ARM_EHABI
+ // Remove the thumb bit so the IP represents the actual instruction address.
+ // This matches the behaviour of _Unwind_GetIP on arm.
+ pc &= (pint_t)~0x1;
+#endif
+
+ // If the last line of a function is a "throw" the compiler sometimes
+ // emits no instructions after the call to __cxa_throw. This means
+ // the return address is actually the start of the next function.
+ // To disambiguate this, back up the pc when we know it is a return
+ // address.
+ if (isReturnAddress)
+ --pc;
+
+ // Ask address space object to find unwind sections for this pc.
+ UnwindInfoSections sects;
+ if (_addressSpace.findUnwindSections(pc, sects)) {
+#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+ // If there is a compact unwind encoding table, look there first.
+ if (sects.compact_unwind_section != 0) {
+ if (this->getInfoFromCompactEncodingSection(pc, sects)) {
+ #if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ // Found info in table, done unless encoding says to use dwarf.
+ uint32_t dwarfOffset;
+ if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
+ if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
+ // found info in dwarf, done
+ return;
+ }
+ }
+ #endif
+ // If unwind table has entry, but entry says there is no unwind info,
+ // record that we have no unwind info.
+ if (_info.format == 0)
+ _unwindInfoMissing = true;
+ return;
+ }
+ }
+#endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ // If there is dwarf unwind info, look there next.
+ if (sects.dwarf_section != 0) {
+ if (this->getInfoFromDwarfSection(pc, sects)) {
+ // found info in dwarf, done
+ return;
+ }
+ }
+#endif
+
+#if _LIBUNWIND_ARM_EHABI
+ // If there is ARM EHABI unwind info, look there next.
+ if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
+ return;
+#endif
+ }
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ // There is no static unwind info for this pc. Look to see if an FDE was
+ // dynamically registered for it.
+ pint_t cachedFDE = DwarfFDECache<A>::findFDE(0, pc);
+ if (cachedFDE != 0) {
+ CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
+ CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
+ const char *msg = CFI_Parser<A>::decodeFDE(_addressSpace,
+ cachedFDE, &fdeInfo, &cieInfo);
+ if (msg == NULL) {
+ typename CFI_Parser<A>::PrologInfo prolog;
+ if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo,
+ pc, &prolog)) {
+ // save off parsed FDE info
+ _info.start_ip = fdeInfo.pcStart;
+ _info.end_ip = fdeInfo.pcEnd;
+ _info.lsda = fdeInfo.lsda;
+ _info.handler = cieInfo.personality;
+ _info.gp = prolog.spExtraArgSize;
+ // Some frameless functions need SP
+ // altered when resuming in function.
+ _info.flags = 0;
+ _info.format = dwarfEncoding();
+ _info.unwind_info = fdeInfo.fdeStart;
+ _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength;
+ _info.extra = 0;
+ return;
+ }
+ }
+ }
+
+ // Lastly, ask AddressSpace object about platform specific ways to locate
+ // other FDEs.
+ pint_t fde;
+ if (_addressSpace.findOtherFDE(pc, fde)) {
+ CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
+ CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
+ if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
+ // Double check this FDE is for a function that includes the pc.
+ if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) {
+ typename CFI_Parser<A>::PrologInfo prolog;
+ if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo,
+ cieInfo, pc, &prolog)) {
+ // save off parsed FDE info
+ _info.start_ip = fdeInfo.pcStart;
+ _info.end_ip = fdeInfo.pcEnd;
+ _info.lsda = fdeInfo.lsda;
+ _info.handler = cieInfo.personality;
+ _info.gp = prolog.spExtraArgSize;
+ _info.flags = 0;
+ _info.format = dwarfEncoding();
+ _info.unwind_info = fdeInfo.fdeStart;
+ _info.unwind_info_size = (uint32_t)fdeInfo.fdeLength;
+ _info.extra = 0;
+ return;
+ }
+ }
+ }
+ }
+#endif // #if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+ // no unwind info, flag that we can't reliably unwind
+ _unwindInfoMissing = true;
+}
+
+template <typename A, typename R>
+int UnwindCursor<A, R>::step() {
+ // Bottom of stack is defined is when unwind info cannot be found.
+ if (_unwindInfoMissing)
+ return UNW_STEP_END;
+
+ // Use unwinding info to modify register set as if function returned.
+ int result;
+#if _LIBUNWIND_SUPPORT_COMPACT_UNWIND
+ result = this->stepWithCompactEncoding();
+#elif _LIBUNWIND_SUPPORT_DWARF_UNWIND
+ result = this->stepWithDwarfFDE();
+#elif _LIBUNWIND_ARM_EHABI
+ result = this->stepWithEHABI();
+#else
+ #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
+ _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
+ _LIBUNWIND_ARM_EHABI
+#endif
+
+ // update info based on new PC
+ if (result == UNW_STEP_SUCCESS) {
+ this->setInfoBasedOnIPRegister(true);
+ if (_unwindInfoMissing)
+ return UNW_STEP_END;
+ if (_info.gp)
+ setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp);
+ }
+
+ return result;
+}
+
+template <typename A, typename R>
+void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
+ *info = _info;
+}
+
+template <typename A, typename R>
+bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
+ unw_word_t *offset) {
+ return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
+ buf, bufLen, offset);
+}
+
+} // namespace libunwind
+
+#endif // __UNWINDCURSOR_HPP__