/thirdparty/breakpad/processor/cfi_frame_info-inl.h
http://github.com/tomahawk-player/tomahawk · C++ Header · 119 lines · 53 code · 17 blank · 49 comment · 12 complexity · 6d16a38c2eb2e54f372cb65da56bca6a MD5 · raw file
- // -*- mode: C++ -*-
- // Copyright (c) 2010, Google Inc.
- // All rights reserved.
- //
- // Redistribution and use in source and binary forms, with or without
- // modification, are permitted provided that the following conditions are
- // met:
- //
- // * Redistributions of source code must retain the above copyright
- // notice, this list of conditions and the following disclaimer.
- // * Redistributions in binary form must reproduce the above
- // copyright notice, this list of conditions and the following disclaimer
- // in the documentation and/or other materials provided with the
- // distribution.
- // * Neither the name of Google Inc. nor the names of its
- // contributors may be used to endorse or promote products derived from
- // this software without specific prior written permission.
- //
- // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
- // cfi_frame_info-inl.h: Definitions for cfi_frame_info.h inlined functions.
- #ifndef PROCESSOR_CFI_FRAME_INFO_INL_H_
- #define PROCESSOR_CFI_FRAME_INFO_INL_H_
- #include <string.h>
- namespace google_breakpad {
- template <typename RegisterType, class RawContextType>
- bool SimpleCFIWalker<RegisterType, RawContextType>::FindCallerRegisters(
- const MemoryRegion &memory,
- const CFIFrameInfo &cfi_frame_info,
- const RawContextType &callee_context,
- int callee_validity,
- RawContextType *caller_context,
- int *caller_validity) const {
- typedef CFIFrameInfo::RegisterValueMap<RegisterType> ValueMap;
- ValueMap callee_registers;
- ValueMap caller_registers;
- // Just for brevity.
- typename ValueMap::const_iterator caller_none = caller_registers.end();
- // Populate callee_registers with register values from callee_context.
- for (size_t i = 0; i < map_size_; i++) {
- const RegisterSet &r = register_map_[i];
- if (callee_validity & r.validity_flag)
- callee_registers[r.name] = callee_context.*r.context_member;
- }
- // Apply the rules, and see what register values they yield.
- if (!cfi_frame_info.FindCallerRegs<RegisterType>(callee_registers, memory,
- &caller_registers))
- return false;
- // Populate *caller_context with the values the rules placed in
- // caller_registers.
- memset(caller_context, 0xda, sizeof(*caller_context));
- *caller_validity = 0;
- for (size_t i = 0; i < map_size_; i++) {
- const RegisterSet &r = register_map_[i];
- typename ValueMap::const_iterator caller_entry;
- // Did the rules provide a value for this register by its name?
- caller_entry = caller_registers.find(r.name);
- if (caller_entry != caller_none) {
- caller_context->*r.context_member = caller_entry->second;
- *caller_validity |= r.validity_flag;
- continue;
- }
- // Did the rules provide a value for this register under its
- // alternate name?
- if (r.alternate_name) {
- caller_entry = caller_registers.find(r.alternate_name);
- if (caller_entry != caller_none) {
- caller_context->*r.context_member = caller_entry->second;
- *caller_validity |= r.validity_flag;
- continue;
- }
- }
- // Is this a callee-saves register? The walker assumes that these
- // still hold the caller's value if the CFI doesn't mention them.
- //
- // Note that other frame walkers may fail to recover callee-saves
- // registers; for example, the x86 "traditional" strategy only
- // recovers %eip, %esp, and %ebp, even though %ebx, %esi, and %edi
- // are callee-saves, too. It is not correct to blindly set the
- // valid bit for all callee-saves registers, without first
- // checking its validity bit in the callee.
- if (r.callee_saves && (callee_validity & r.validity_flag) != 0) {
- caller_context->*r.context_member = callee_context.*r.context_member;
- *caller_validity |= r.validity_flag;
- continue;
- }
- // Otherwise, the register's value is unknown.
- }
- return true;
- }
- } // namespace google_breakpad
- #endif // PROCESSOR_CFI_FRAME_INFO_INL_H_