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Diffstat (limited to 'externals/breakpad/src/processor/cfi_frame_info-inl.h')
| -rw-r--r-- | externals/breakpad/src/processor/cfi_frame_info-inl.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/externals/breakpad/src/processor/cfi_frame_info-inl.h b/externals/breakpad/src/processor/cfi_frame_info-inl.h new file mode 100644 index 0000000000..acfc4f795a --- /dev/null +++ b/externals/breakpad/src/processor/cfi_frame_info-inl.h @@ -0,0 +1,118 @@ +// -*- mode: C++ -*- + +// Copyright 2010 Google LLC +// +// 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 LLC 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_ |