diff options
Diffstat (limited to 'src/common/linux/dwarf_cfi_to_module.cc')
-rw-r--r-- | src/common/linux/dwarf_cfi_to_module.cc | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/common/linux/dwarf_cfi_to_module.cc b/src/common/linux/dwarf_cfi_to_module.cc new file mode 100644 index 00000000..d7946a0e --- /dev/null +++ b/src/common/linux/dwarf_cfi_to_module.cc @@ -0,0 +1,187 @@ +// -*- 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> + +// Implementation of google_breakpad::DwarfCFIToModule. +// See dwarf_cfi_to_module.h for details. + +#include <sstream> + +#include "common/linux/dwarf_cfi_to_module.h" + +namespace google_breakpad { + +using std::ostringstream; + +bool DwarfCFIToModule::Entry(size_t offset, uint64 address, uint64 length, + uint8 version, const string &augmentation, + unsigned return_address) { + assert(!entry_); + // The latest CFI format version we understand is version 3. + if (version > 3) + return false; + // We only handle non-augmented DWARF unwinding data at the moment. + if (!augmentation.empty()) + return false; + + // Get ready to collect entries. + entry_ = new Module::StackFrameEntry; + entry_->address = address; + entry_->size = length; + entry_offset_ = offset; + return_address_ = return_address; + + // Breakpad STACK CFI records must provide a .ra rule, but DWARF CFI + // may not establish any rule for .ra if the return address column + // is an ordinary register, and that register holds the return + // address on entry to the function. So establish an initial .ra + // rule citing the return address register. + if (return_address_ < register_names_.size()) + entry_->initial_rules[".ra"] = register_names_[return_address_]; + + return true; +} + +string DwarfCFIToModule::RegisterName(int i) { + assert(entry_); + if (i < 0) { + assert(i == kCFARegister); + return ".cfa"; + } + unsigned reg = i; + if (reg == return_address_) + return ".ra"; + + if (0 <= reg && reg < register_names_.size()) + return register_names_[reg]; + + reporter_->UnnamedRegister(entry_offset_, reg); + char buf[30]; + sprintf(buf, "unnamed_register%u", reg); + return buf; +} + +void DwarfCFIToModule::Record(Module::Address address, int reg, + const string &rule) { + assert(entry_); + // Is this one of this entry's initial rules? + if (address == entry_->address) + entry_->initial_rules[RegisterName(reg)] = rule; + // File it under the appropriate address. + else + entry_->rule_changes[address][RegisterName(reg)] = rule; +} + +bool DwarfCFIToModule::UndefinedRule(uint64 address, int reg) { + reporter_->UndefinedNotSupported(entry_offset_, RegisterName(reg)); + // Treat this as a non-fatal error. + return true; +} + +bool DwarfCFIToModule::SameValueRule(uint64 address, int reg) { + ostringstream s; + s << RegisterName(reg); + Record(address, reg, s.str()); + return true; +} + +bool DwarfCFIToModule::OffsetRule(uint64 address, int reg, + int base_register, long offset) { + ostringstream s; + s << RegisterName(base_register) << " " << offset << " + ^"; + Record(address, reg, s.str()); + return true; +} + +bool DwarfCFIToModule::ValOffsetRule(uint64 address, int reg, + int base_register, long offset) { + ostringstream s; + s << RegisterName(base_register) << " " << offset << " +"; + Record(address, reg, s.str()); + return true; +} + +bool DwarfCFIToModule::RegisterRule(uint64 address, int reg, + int base_register) { + ostringstream s; + s << RegisterName(base_register); + Record(address, reg, s.str()); + return true; +} + +bool DwarfCFIToModule::ExpressionRule(uint64 address, int reg, + const string &expression) { + reporter_->ExpressionsNotSupported(entry_offset_, RegisterName(reg)); + // Treat this as a non-fatal error. + return true; +} + +bool DwarfCFIToModule::ValExpressionRule(uint64 address, int reg, + const string &expression) { + reporter_->ExpressionsNotSupported(entry_offset_, RegisterName(reg)); + // Treat this as a non-fatal error. + return true; +} + +bool DwarfCFIToModule::End() { + module_->AddStackFrameEntry(entry_); + entry_ = NULL; + return true; +} + +void DwarfCFIToModule::Reporter::UnnamedRegister(size_t offset, int reg) { + fprintf(stderr, "%s, section '%s': " + "the call frame entry at offset 0x%zx refers to register %d," + " whose name we don't know\n", + file_.c_str(), section_.c_str(), offset, reg); +} + +void DwarfCFIToModule::Reporter::UndefinedNotSupported(size_t offset, + const string ®) { + fprintf(stderr, "%s, section '%s': " + "the call frame entry at offset 0x%zx sets the rule for " + "register '%s' to 'undefined', but the Breakpad symbol file format" + " cannot express this\n", + file_.c_str(), section_.c_str(), offset, reg.c_str()); +} + +void DwarfCFIToModule::Reporter::ExpressionsNotSupported(size_t offset, + const string ®) { + fprintf(stderr, "%s, section '%s': " + "the call frame entry at offset 0x%zx uses a DWARF expression to" + " describe how to recover register '%s', " + " but this translator cannot yet translate DWARF expressions to" + " Breakpad postfix expressions\n", + file_.c_str(), section_.c_str(), offset, reg.c_str()); +} + +} // namespace google_breakpad |