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diff --git a/tools/profiler/lul/LulDwarf.cpp b/tools/profiler/lul/LulDwarf.cpp
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+++ b/tools/profiler/lul/LulDwarf.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+
+// 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.
+
+// CFI reader author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Implementation of dwarf2reader::LineInfo, dwarf2reader::CompilationUnit,
+// and dwarf2reader::CallFrameInfo. See dwarf2reader.h for details.
+
+// This file is derived from the following files in
+// toolkit/crashreporter/google-breakpad:
+// src/common/dwarf/bytereader.cc
+// src/common/dwarf/dwarf2reader.cc
+// src/common/dwarf_cfi_to_module.cc
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <map>
+#include <stack>
+#include <string>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Sprintf.h"
+
+#include "LulCommonExt.h"
+#include "LulDwarfInt.h"
+
+
+// Set this to 1 for verbose logging
+#define DEBUG_DWARF 0
+
+
+namespace lul {
+
+using std::string;
+
+ByteReader::ByteReader(enum Endianness endian)
+ :offset_reader_(NULL), address_reader_(NULL), endian_(endian),
+ address_size_(0), offset_size_(0),
+ have_section_base_(), have_text_base_(), have_data_base_(),
+ have_function_base_() { }
+
+ByteReader::~ByteReader() { }
+
+void ByteReader::SetOffsetSize(uint8 size) {
+ offset_size_ = size;
+ MOZ_ASSERT(size == 4 || size == 8);
+ if (size == 4) {
+ this->offset_reader_ = &ByteReader::ReadFourBytes;
+ } else {
+ this->offset_reader_ = &ByteReader::ReadEightBytes;
+ }
+}
+
+void ByteReader::SetAddressSize(uint8 size) {
+ address_size_ = size;
+ MOZ_ASSERT(size == 4 || size == 8);
+ if (size == 4) {
+ this->address_reader_ = &ByteReader::ReadFourBytes;
+ } else {
+ this->address_reader_ = &ByteReader::ReadEightBytes;
+ }
+}
+
+uint64 ByteReader::ReadInitialLength(const char* start, size_t* len) {
+ const uint64 initial_length = ReadFourBytes(start);
+ start += 4;
+
+ // In DWARF2/3, if the initial length is all 1 bits, then the offset
+ // size is 8 and we need to read the next 8 bytes for the real length.
+ if (initial_length == 0xffffffff) {
+ SetOffsetSize(8);
+ *len = 12;
+ return ReadOffset(start);
+ } else {
+ SetOffsetSize(4);
+ *len = 4;
+ }
+ return initial_length;
+}
+
+bool ByteReader::ValidEncoding(DwarfPointerEncoding encoding) const {
+ if (encoding == DW_EH_PE_omit) return true;
+ if (encoding == DW_EH_PE_aligned) return true;
+ if ((encoding & 0x7) > DW_EH_PE_udata8)
+ return false;
+ if ((encoding & 0x70) > DW_EH_PE_funcrel)
+ return false;
+ return true;
+}
+
+bool ByteReader::UsableEncoding(DwarfPointerEncoding encoding) const {
+ switch (encoding & 0x70) {
+ case DW_EH_PE_absptr: return true;
+ case DW_EH_PE_pcrel: return have_section_base_;
+ case DW_EH_PE_textrel: return have_text_base_;
+ case DW_EH_PE_datarel: return have_data_base_;
+ case DW_EH_PE_funcrel: return have_function_base_;
+ default: return false;
+ }
+}
+
+uint64 ByteReader::ReadEncodedPointer(const char *buffer,
+ DwarfPointerEncoding encoding,
+ size_t *len) const {
+ // UsableEncoding doesn't approve of DW_EH_PE_omit, so we shouldn't
+ // see it here.
+ MOZ_ASSERT(encoding != DW_EH_PE_omit);
+
+ // The Linux Standards Base 4.0 does not make this clear, but the
+ // GNU tools (gcc/unwind-pe.h; readelf/dwarf.c; gdb/dwarf2-frame.c)
+ // agree that aligned pointers are always absolute, machine-sized,
+ // machine-signed pointers.
+ if (encoding == DW_EH_PE_aligned) {
+ MOZ_ASSERT(have_section_base_);
+
+ // We don't need to align BUFFER in *our* address space. Rather, we
+ // need to find the next position in our buffer that would be aligned
+ // when the .eh_frame section the buffer contains is loaded into the
+ // program's memory. So align assuming that buffer_base_ gets loaded at
+ // address section_base_, where section_base_ itself may or may not be
+ // aligned.
+
+ // First, find the offset to START from the closest prior aligned
+ // address.
+ uint64 skew = section_base_ & (AddressSize() - 1);
+ // Now find the offset from that aligned address to buffer.
+ uint64 offset = skew + (buffer - buffer_base_);
+ // Round up to the next boundary.
+ uint64 aligned = (offset + AddressSize() - 1) & -AddressSize();
+ // Convert back to a pointer.
+ const char *aligned_buffer = buffer_base_ + (aligned - skew);
+ // Finally, store the length and actually fetch the pointer.
+ *len = aligned_buffer - buffer + AddressSize();
+ return ReadAddress(aligned_buffer);
+ }
+
+ // Extract the value first, ignoring whether it's a pointer or an
+ // offset relative to some base.
+ uint64 offset;
+ switch (encoding & 0x0f) {
+ case DW_EH_PE_absptr:
+ // DW_EH_PE_absptr is weird, as it is used as a meaningful value for
+ // both the high and low nybble of encoding bytes. When it appears in
+ // the high nybble, it means that the pointer is absolute, not an
+ // offset from some base address. When it appears in the low nybble,
+ // as here, it means that the pointer is stored as a normal
+ // machine-sized and machine-signed address. A low nybble of
+ // DW_EH_PE_absptr does not imply that the pointer is absolute; it is
+ // correct for us to treat the value as an offset from a base address
+ // if the upper nybble is not DW_EH_PE_absptr.
+ offset = ReadAddress(buffer);
+ *len = AddressSize();
+ break;
+
+ case DW_EH_PE_uleb128:
+ offset = ReadUnsignedLEB128(buffer, len);
+ break;
+
+ case DW_EH_PE_udata2:
+ offset = ReadTwoBytes(buffer);
+ *len = 2;
+ break;
+
+ case DW_EH_PE_udata4:
+ offset = ReadFourBytes(buffer);
+ *len = 4;
+ break;
+
+ case DW_EH_PE_udata8:
+ offset = ReadEightBytes(buffer);
+ *len = 8;
+ break;
+
+ case DW_EH_PE_sleb128:
+ offset = ReadSignedLEB128(buffer, len);
+ break;
+
+ case DW_EH_PE_sdata2:
+ offset = ReadTwoBytes(buffer);
+ // Sign-extend from 16 bits.
+ offset = (offset ^ 0x8000) - 0x8000;
+ *len = 2;
+ break;
+
+ case DW_EH_PE_sdata4:
+ offset = ReadFourBytes(buffer);
+ // Sign-extend from 32 bits.
+ offset = (offset ^ 0x80000000ULL) - 0x80000000ULL;
+ *len = 4;
+ break;
+
+ case DW_EH_PE_sdata8:
+ // No need to sign-extend; this is the full width of our type.
+ offset = ReadEightBytes(buffer);
+ *len = 8;
+ break;
+
+ default:
+ abort();
+ }
+
+ // Find the appropriate base address.
+ uint64 base;
+ switch (encoding & 0x70) {
+ case DW_EH_PE_absptr:
+ base = 0;
+ break;
+
+ case DW_EH_PE_pcrel:
+ MOZ_ASSERT(have_section_base_);
+ base = section_base_ + (buffer - buffer_base_);
+ break;
+
+ case DW_EH_PE_textrel:
+ MOZ_ASSERT(have_text_base_);
+ base = text_base_;
+ break;
+
+ case DW_EH_PE_datarel:
+ MOZ_ASSERT(have_data_base_);
+ base = data_base_;
+ break;
+
+ case DW_EH_PE_funcrel:
+ MOZ_ASSERT(have_function_base_);
+ base = function_base_;
+ break;
+
+ default:
+ abort();
+ }
+
+ uint64 pointer = base + offset;
+
+ // Remove inappropriate upper bits.
+ if (AddressSize() == 4)
+ pointer = pointer & 0xffffffff;
+ else
+ MOZ_ASSERT(AddressSize() == sizeof(uint64));
+
+ return pointer;
+}
+
+
+// A DWARF rule for recovering the address or value of a register, or
+// computing the canonical frame address. There is one subclass of this for
+// each '*Rule' member function in CallFrameInfo::Handler.
+//
+// It's annoying that we have to handle Rules using pointers (because
+// the concrete instances can have an arbitrary size). They're small,
+// so it would be much nicer if we could just handle them by value
+// instead of fretting about ownership and destruction.
+//
+// It seems like all these could simply be instances of std::tr1::bind,
+// except that we need instances to be EqualityComparable, too.
+//
+// This could logically be nested within State, but then the qualified names
+// get horrendous.
+class CallFrameInfo::Rule {
+ public:
+ virtual ~Rule() { }
+
+ // Tell HANDLER that, at ADDRESS in the program, REGISTER can be
+ // recovered using this rule. If REGISTER is kCFARegister, then this rule
+ // describes how to compute the canonical frame address. Return what the
+ // HANDLER member function returned.
+ virtual bool Handle(Handler *handler, uint64 address, int register) const = 0;
+
+ // Equality on rules. We use these to decide which rules we need
+ // to report after a DW_CFA_restore_state instruction.
+ virtual bool operator==(const Rule &rhs) const = 0;
+
+ bool operator!=(const Rule &rhs) const { return ! (*this == rhs); }
+
+ // Return a pointer to a copy of this rule.
+ virtual Rule *Copy() const = 0;
+
+ // If this is a base+offset rule, change its base register to REG.
+ // Otherwise, do nothing. (Ugly, but required for DW_CFA_def_cfa_register.)
+ virtual void SetBaseRegister(unsigned reg) { }
+
+ // If this is a base+offset rule, change its offset to OFFSET. Otherwise,
+ // do nothing. (Ugly, but required for DW_CFA_def_cfa_offset.)
+ virtual void SetOffset(long long offset) { }
+
+ // A RTTI workaround, to make it possible to implement equality
+ // comparisons on classes derived from this one.
+ enum CFIRTag {
+ CFIR_UNDEFINED_RULE,
+ CFIR_SAME_VALUE_RULE,
+ CFIR_OFFSET_RULE,
+ CFIR_VAL_OFFSET_RULE,
+ CFIR_REGISTER_RULE,
+ CFIR_EXPRESSION_RULE,
+ CFIR_VAL_EXPRESSION_RULE
+ };
+
+ // Produce the tag that identifies the child class of this object.
+ virtual CFIRTag getTag() const = 0;
+};
+
+// Rule: the value the register had in the caller cannot be recovered.
+class CallFrameInfo::UndefinedRule: public CallFrameInfo::Rule {
+ public:
+ UndefinedRule() { }
+ ~UndefinedRule() { }
+ CFIRTag getTag() const { return CFIR_UNDEFINED_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->UndefinedRule(address, reg);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_UNDEFINED_RULE) return false;
+ return true;
+ }
+ Rule *Copy() const { return new UndefinedRule(*this); }
+};
+
+// Rule: the register's value is the same as that it had in the caller.
+class CallFrameInfo::SameValueRule: public CallFrameInfo::Rule {
+ public:
+ SameValueRule() { }
+ ~SameValueRule() { }
+ CFIRTag getTag() const { return CFIR_SAME_VALUE_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->SameValueRule(address, reg);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_SAME_VALUE_RULE) return false;
+ return true;
+ }
+ Rule *Copy() const { return new SameValueRule(*this); }
+};
+
+// Rule: the register is saved at OFFSET from BASE_REGISTER. BASE_REGISTER
+// may be CallFrameInfo::Handler::kCFARegister.
+class CallFrameInfo::OffsetRule: public CallFrameInfo::Rule {
+ public:
+ OffsetRule(int base_register, long offset)
+ : base_register_(base_register), offset_(offset) { }
+ ~OffsetRule() { }
+ CFIRTag getTag() const { return CFIR_OFFSET_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->OffsetRule(address, reg, base_register_, offset_);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_OFFSET_RULE) return false;
+ const OffsetRule *our_rhs = static_cast<const OffsetRule *>(&rhs);
+ return (base_register_ == our_rhs->base_register_ &&
+ offset_ == our_rhs->offset_);
+ }
+ Rule *Copy() const { return new OffsetRule(*this); }
+ // We don't actually need SetBaseRegister or SetOffset here, since they
+ // are only ever applied to CFA rules, for DW_CFA_def_cfa_offset, and it
+ // doesn't make sense to use OffsetRule for computing the CFA: it
+ // computes the address at which a register is saved, not a value.
+ private:
+ int base_register_;
+ long offset_;
+};
+
+// Rule: the value the register had in the caller is the value of
+// BASE_REGISTER plus offset. BASE_REGISTER may be
+// CallFrameInfo::Handler::kCFARegister.
+class CallFrameInfo::ValOffsetRule: public CallFrameInfo::Rule {
+ public:
+ ValOffsetRule(int base_register, long offset)
+ : base_register_(base_register), offset_(offset) { }
+ ~ValOffsetRule() { }
+ CFIRTag getTag() const { return CFIR_VAL_OFFSET_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ValOffsetRule(address, reg, base_register_, offset_);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_VAL_OFFSET_RULE) return false;
+ const ValOffsetRule *our_rhs = static_cast<const ValOffsetRule *>(&rhs);
+ return (base_register_ == our_rhs->base_register_ &&
+ offset_ == our_rhs->offset_);
+ }
+ Rule *Copy() const { return new ValOffsetRule(*this); }
+ void SetBaseRegister(unsigned reg) { base_register_ = reg; }
+ void SetOffset(long long offset) { offset_ = offset; }
+ private:
+ int base_register_;
+ long offset_;
+};
+
+// Rule: the register has been saved in another register REGISTER_NUMBER_.
+class CallFrameInfo::RegisterRule: public CallFrameInfo::Rule {
+ public:
+ explicit RegisterRule(int register_number)
+ : register_number_(register_number) { }
+ ~RegisterRule() { }
+ CFIRTag getTag() const { return CFIR_REGISTER_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->RegisterRule(address, reg, register_number_);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_REGISTER_RULE) return false;
+ const RegisterRule *our_rhs = static_cast<const RegisterRule *>(&rhs);
+ return (register_number_ == our_rhs->register_number_);
+ }
+ Rule *Copy() const { return new RegisterRule(*this); }
+ private:
+ int register_number_;
+};
+
+// Rule: EXPRESSION evaluates to the address at which the register is saved.
+class CallFrameInfo::ExpressionRule: public CallFrameInfo::Rule {
+ public:
+ explicit ExpressionRule(const string &expression)
+ : expression_(expression) { }
+ ~ExpressionRule() { }
+ CFIRTag getTag() const { return CFIR_EXPRESSION_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ExpressionRule(address, reg, expression_);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_EXPRESSION_RULE) return false;
+ const ExpressionRule *our_rhs = static_cast<const ExpressionRule *>(&rhs);
+ return (expression_ == our_rhs->expression_);
+ }
+ Rule *Copy() const { return new ExpressionRule(*this); }
+ private:
+ string expression_;
+};
+
+// Rule: EXPRESSION evaluates to the previous value of the register.
+class CallFrameInfo::ValExpressionRule: public CallFrameInfo::Rule {
+ public:
+ explicit ValExpressionRule(const string &expression)
+ : expression_(expression) { }
+ ~ValExpressionRule() { }
+ CFIRTag getTag() const { return CFIR_VAL_EXPRESSION_RULE; }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ValExpressionRule(address, reg, expression_);
+ }
+ bool operator==(const Rule &rhs) const {
+ if (rhs.getTag() != CFIR_VAL_EXPRESSION_RULE) return false;
+ const ValExpressionRule *our_rhs =
+ static_cast<const ValExpressionRule *>(&rhs);
+ return (expression_ == our_rhs->expression_);
+ }
+ Rule *Copy() const { return new ValExpressionRule(*this); }
+ private:
+ string expression_;
+};
+
+// A map from register numbers to rules.
+class CallFrameInfo::RuleMap {
+ public:
+ RuleMap() : cfa_rule_(NULL) { }
+ RuleMap(const RuleMap &rhs) : cfa_rule_(NULL) { *this = rhs; }
+ ~RuleMap() { Clear(); }
+
+ RuleMap &operator=(const RuleMap &rhs);
+
+ // Set the rule for computing the CFA to RULE. Take ownership of RULE.
+ void SetCFARule(Rule *rule) { delete cfa_rule_; cfa_rule_ = rule; }
+
+ // Return the current CFA rule. Unlike RegisterRule, this RuleMap retains
+ // ownership of the rule. We use this for DW_CFA_def_cfa_offset and
+ // DW_CFA_def_cfa_register, and for detecting references to the CFA before
+ // a rule for it has been established.
+ Rule *CFARule() const { return cfa_rule_; }
+
+ // Return the rule for REG, or NULL if there is none. The caller takes
+ // ownership of the result.
+ Rule *RegisterRule(int reg) const;
+
+ // Set the rule for computing REG to RULE. Take ownership of RULE.
+ void SetRegisterRule(int reg, Rule *rule);
+
+ // Make all the appropriate calls to HANDLER as if we were changing from
+ // this RuleMap to NEW_RULES at ADDRESS. We use this to implement
+ // DW_CFA_restore_state, where lots of rules can change simultaneously.
+ // Return true if all handlers returned true; otherwise, return false.
+ bool HandleTransitionTo(Handler *handler, uint64 address,
+ const RuleMap &new_rules) const;
+
+ private:
+ // A map from register numbers to Rules.
+ typedef std::map<int, Rule *> RuleByNumber;
+
+ // Remove all register rules and clear cfa_rule_.
+ void Clear();
+
+ // The rule for computing the canonical frame address. This RuleMap owns
+ // this rule.
+ Rule *cfa_rule_;
+
+ // A map from register numbers to postfix expressions to recover
+ // their values. This RuleMap owns the Rules the map refers to.
+ RuleByNumber registers_;
+};
+
+CallFrameInfo::RuleMap &CallFrameInfo::RuleMap::operator=(const RuleMap &rhs) {
+ Clear();
+ // Since each map owns the rules it refers to, assignment must copy them.
+ if (rhs.cfa_rule_) cfa_rule_ = rhs.cfa_rule_->Copy();
+ for (RuleByNumber::const_iterator it = rhs.registers_.begin();
+ it != rhs.registers_.end(); it++)
+ registers_[it->first] = it->second->Copy();
+ return *this;
+}
+
+CallFrameInfo::Rule *CallFrameInfo::RuleMap::RegisterRule(int reg) const {
+ MOZ_ASSERT(reg != Handler::kCFARegister);
+ RuleByNumber::const_iterator it = registers_.find(reg);
+ if (it != registers_.end())
+ return it->second->Copy();
+ else
+ return NULL;
+}
+
+void CallFrameInfo::RuleMap::SetRegisterRule(int reg, Rule *rule) {
+ MOZ_ASSERT(reg != Handler::kCFARegister);
+ MOZ_ASSERT(rule);
+ Rule **slot = &registers_[reg];
+ delete *slot;
+ *slot = rule;
+}
+
+bool CallFrameInfo::RuleMap::HandleTransitionTo(
+ Handler *handler,
+ uint64 address,
+ const RuleMap &new_rules) const {
+ // Transition from cfa_rule_ to new_rules.cfa_rule_.
+ if (cfa_rule_ && new_rules.cfa_rule_) {
+ if (*cfa_rule_ != *new_rules.cfa_rule_ &&
+ !new_rules.cfa_rule_->Handle(handler, address, Handler::kCFARegister))
+ return false;
+ } else if (cfa_rule_) {
+ // this RuleMap has a CFA rule but new_rules doesn't.
+ // CallFrameInfo::Handler has no way to handle this --- and shouldn't;
+ // it's garbage input. The instruction interpreter should have
+ // detected this and warned, so take no action here.
+ } else if (new_rules.cfa_rule_) {
+ // This shouldn't be possible: NEW_RULES is some prior state, and
+ // there's no way to remove entries.
+ MOZ_ASSERT(0);
+ } else {
+ // Both CFA rules are empty. No action needed.
+ }
+
+ // Traverse the two maps in order by register number, and report
+ // whatever differences we find.
+ RuleByNumber::const_iterator old_it = registers_.begin();
+ RuleByNumber::const_iterator new_it = new_rules.registers_.begin();
+ while (old_it != registers_.end() && new_it != new_rules.registers_.end()) {
+ if (old_it->first < new_it->first) {
+ // This RuleMap has an entry for old_it->first, but NEW_RULES
+ // doesn't.
+ //
+ // This isn't really the right thing to do, but since CFI generally
+ // only mentions callee-saves registers, and GCC's convention for
+ // callee-saves registers is that they are unchanged, it's a good
+ // approximation.
+ if (!handler->SameValueRule(address, old_it->first))
+ return false;
+ old_it++;
+ } else if (old_it->first > new_it->first) {
+ // NEW_RULES has entry for new_it->first, but this RuleMap
+ // doesn't. This shouldn't be possible: NEW_RULES is some prior
+ // state, and there's no way to remove entries.
+ MOZ_ASSERT(0);
+ } else {
+ // Both maps have an entry for this register. Report the new
+ // rule if it is different.
+ if (*old_it->second != *new_it->second &&
+ !new_it->second->Handle(handler, address, new_it->first))
+ return false;
+ new_it++, old_it++;
+ }
+ }
+ // Finish off entries from this RuleMap with no counterparts in new_rules.
+ while (old_it != registers_.end()) {
+ if (!handler->SameValueRule(address, old_it->first))
+ return false;
+ old_it++;
+ }
+ // Since we only make transitions from a rule set to some previously
+ // saved rule set, and we can only add rules to the map, NEW_RULES
+ // must have fewer rules than *this.
+ MOZ_ASSERT(new_it == new_rules.registers_.end());
+
+ return true;
+}
+
+// Remove all register rules and clear cfa_rule_.
+void CallFrameInfo::RuleMap::Clear() {
+ delete cfa_rule_;
+ cfa_rule_ = NULL;
+ for (RuleByNumber::iterator it = registers_.begin();
+ it != registers_.end(); it++)
+ delete it->second;
+ registers_.clear();
+}
+
+// The state of the call frame information interpreter as it processes
+// instructions from a CIE and FDE.
+class CallFrameInfo::State {
+ public:
+ // Create a call frame information interpreter state with the given
+ // reporter, reader, handler, and initial call frame info address.
+ State(ByteReader *reader, Handler *handler, Reporter *reporter,
+ uint64 address)
+ : reader_(reader), handler_(handler), reporter_(reporter),
+ address_(address), entry_(NULL), cursor_(NULL),
+ saved_rules_(NULL) { }
+
+ ~State() {
+ if (saved_rules_)
+ delete saved_rules_;
+ }
+
+ // Interpret instructions from CIE, save the resulting rule set for
+ // DW_CFA_restore instructions, and return true. On error, report
+ // the problem to reporter_ and return false.
+ bool InterpretCIE(const CIE &cie);
+
+ // Interpret instructions from FDE, and return true. On error,
+ // report the problem to reporter_ and return false.
+ bool InterpretFDE(const FDE &fde);
+
+ private:
+ // The operands of a CFI instruction, for ParseOperands.
+ struct Operands {
+ unsigned register_number; // A register number.
+ uint64 offset; // An offset or address.
+ long signed_offset; // A signed offset.
+ string expression; // A DWARF expression.
+ };
+
+ // Parse CFI instruction operands from STATE's instruction stream as
+ // described by FORMAT. On success, populate OPERANDS with the
+ // results, and return true. On failure, report the problem and
+ // return false.
+ //
+ // Each character of FORMAT should be one of the following:
+ //
+ // 'r' unsigned LEB128 register number (OPERANDS->register_number)
+ // 'o' unsigned LEB128 offset (OPERANDS->offset)
+ // 's' signed LEB128 offset (OPERANDS->signed_offset)
+ // 'a' machine-size address (OPERANDS->offset)
+ // (If the CIE has a 'z' augmentation string, 'a' uses the
+ // encoding specified by the 'R' argument.)
+ // '1' a one-byte offset (OPERANDS->offset)
+ // '2' a two-byte offset (OPERANDS->offset)
+ // '4' a four-byte offset (OPERANDS->offset)
+ // '8' an eight-byte offset (OPERANDS->offset)
+ // 'e' a DW_FORM_block holding a (OPERANDS->expression)
+ // DWARF expression
+ bool ParseOperands(const char *format, Operands *operands);
+
+ // Interpret one CFI instruction from STATE's instruction stream, update
+ // STATE, report any rule changes to handler_, and return true. On
+ // failure, report the problem and return false.
+ bool DoInstruction();
+
+ // The following Do* member functions are subroutines of DoInstruction,
+ // factoring out the actual work of operations that have several
+ // different encodings.
+
+ // Set the CFA rule to be the value of BASE_REGISTER plus OFFSET, and
+ // return true. On failure, report and return false. (Used for
+ // DW_CFA_def_cfa and DW_CFA_def_cfa_sf.)
+ bool DoDefCFA(unsigned base_register, long offset);
+
+ // Change the offset of the CFA rule to OFFSET, and return true. On
+ // failure, report and return false. (Subroutine for
+ // DW_CFA_def_cfa_offset and DW_CFA_def_cfa_offset_sf.)
+ bool DoDefCFAOffset(long offset);
+
+ // Specify that REG can be recovered using RULE, and return true. On
+ // failure, report and return false.
+ bool DoRule(unsigned reg, Rule *rule);
+
+ // Specify that REG can be found at OFFSET from the CFA, and return true.
+ // On failure, report and return false. (Subroutine for DW_CFA_offset,
+ // DW_CFA_offset_extended, and DW_CFA_offset_extended_sf.)
+ bool DoOffset(unsigned reg, long offset);
+
+ // Specify that the caller's value for REG is the CFA plus OFFSET,
+ // and return true. On failure, report and return false. (Subroutine
+ // for DW_CFA_val_offset and DW_CFA_val_offset_sf.)
+ bool DoValOffset(unsigned reg, long offset);
+
+ // Restore REG to the rule established in the CIE, and return true. On
+ // failure, report and return false. (Subroutine for DW_CFA_restore and
+ // DW_CFA_restore_extended.)
+ bool DoRestore(unsigned reg);
+
+ // Return the section offset of the instruction at cursor. For use
+ // in error messages.
+ uint64 CursorOffset() { return entry_->offset + (cursor_ - entry_->start); }
+
+ // Report that entry_ is incomplete, and return false. For brevity.
+ bool ReportIncomplete() {
+ reporter_->Incomplete(entry_->offset, entry_->kind);
+ return false;
+ }
+
+ // For reading multi-byte values with the appropriate endianness.
+ ByteReader *reader_;
+
+ // The handler to which we should report the data we find.
+ Handler *handler_;
+
+ // For reporting problems in the info we're parsing.
+ Reporter *reporter_;
+
+ // The code address to which the next instruction in the stream applies.
+ uint64 address_;
+
+ // The entry whose instructions we are currently processing. This is
+ // first a CIE, and then an FDE.
+ const Entry *entry_;
+
+ // The next instruction to process.
+ const char *cursor_;
+
+ // The current set of rules.
+ RuleMap rules_;
+
+ // The set of rules established by the CIE, used by DW_CFA_restore
+ // and DW_CFA_restore_extended. We set this after interpreting the
+ // CIE's instructions.
+ RuleMap cie_rules_;
+
+ // A stack of saved states, for DW_CFA_remember_state and
+ // DW_CFA_restore_state.
+ std::stack<RuleMap>* saved_rules_;
+};
+
+bool CallFrameInfo::State::InterpretCIE(const CIE &cie) {
+ entry_ = &cie;
+ cursor_ = entry_->instructions;
+ while (cursor_ < entry_->end)
+ if (!DoInstruction())
+ return false;
+ // Note the rules established by the CIE, for use by DW_CFA_restore
+ // and DW_CFA_restore_extended.
+ cie_rules_ = rules_;
+ return true;
+}
+
+bool CallFrameInfo::State::InterpretFDE(const FDE &fde) {
+ entry_ = &fde;
+ cursor_ = entry_->instructions;
+ while (cursor_ < entry_->end)
+ if (!DoInstruction())
+ return false;
+ return true;
+}
+
+bool CallFrameInfo::State::ParseOperands(const char *format,
+ Operands *operands) {
+ size_t len;
+ const char *operand;
+
+ for (operand = format; *operand; operand++) {
+ size_t bytes_left = entry_->end - cursor_;
+ switch (*operand) {
+ case 'r':
+ operands->register_number = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 'o':
+ operands->offset = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 's':
+ operands->signed_offset = reader_->ReadSignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 'a':
+ operands->offset =
+ reader_->ReadEncodedPointer(cursor_, entry_->cie->pointer_encoding,
+ &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case '1':
+ if (1 > bytes_left) return ReportIncomplete();
+ operands->offset = static_cast<unsigned char>(*cursor_++);
+ break;
+
+ case '2':
+ if (2 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadTwoBytes(cursor_);
+ cursor_ += 2;
+ break;
+
+ case '4':
+ if (4 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadFourBytes(cursor_);
+ cursor_ += 4;
+ break;
+
+ case '8':
+ if (8 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadEightBytes(cursor_);
+ cursor_ += 8;
+ break;
+
+ case 'e': {
+ size_t expression_length = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left || expression_length > bytes_left - len)
+ return ReportIncomplete();
+ cursor_ += len;
+ operands->expression = string(cursor_, expression_length);
+ cursor_ += expression_length;
+ break;
+ }
+
+ default:
+ MOZ_ASSERT(0);
+ }
+ }
+
+ return true;
+}
+
+bool CallFrameInfo::State::DoInstruction() {
+ CIE *cie = entry_->cie;
+ Operands ops;
+
+ // Our entry's kind should have been set by now.
+ MOZ_ASSERT(entry_->kind != kUnknown);
+
+ // We shouldn't have been invoked unless there were more
+ // instructions to parse.
+ MOZ_ASSERT(cursor_ < entry_->end);
+
+ unsigned opcode = *cursor_++;
+ if ((opcode & 0xc0) != 0) {
+ switch (opcode & 0xc0) {
+ // Advance the address.
+ case DW_CFA_advance_loc: {
+ size_t code_offset = opcode & 0x3f;
+ address_ += code_offset * cie->code_alignment_factor;
+ break;
+ }
+
+ // Find a register at an offset from the CFA.
+ case DW_CFA_offset:
+ if (!ParseOperands("o", &ops) ||
+ !DoOffset(opcode & 0x3f, ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Restore the rule established for a register by the CIE.
+ case DW_CFA_restore:
+ if (!DoRestore(opcode & 0x3f)) return false;
+ break;
+
+ // The 'if' above should have excluded this possibility.
+ default:
+ MOZ_ASSERT(0);
+ }
+
+ // Return here, so the big switch below won't be indented.
+ return true;
+ }
+
+ switch (opcode) {
+ // Set the address.
+ case DW_CFA_set_loc:
+ if (!ParseOperands("a", &ops)) return false;
+ address_ = ops.offset;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc1:
+ if (!ParseOperands("1", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc2:
+ if (!ParseOperands("2", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc4:
+ if (!ParseOperands("4", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_MIPS_advance_loc8:
+ if (!ParseOperands("8", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Compute the CFA by adding an offset to a register.
+ case DW_CFA_def_cfa:
+ if (!ParseOperands("ro", &ops) ||
+ !DoDefCFA(ops.register_number, ops.offset))
+ return false;
+ break;
+
+ // Compute the CFA by adding an offset to a register.
+ case DW_CFA_def_cfa_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoDefCFA(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Change the base register used to compute the CFA.
+ case DW_CFA_def_cfa_register: {
+ Rule *cfa_rule = rules_.CFARule();
+ if (!cfa_rule) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ if (!ParseOperands("r", &ops)) return false;
+ cfa_rule->SetBaseRegister(ops.register_number);
+ if (!cfa_rule->Handle(handler_, address_, Handler::kCFARegister))
+ return false;
+ break;
+ }
+
+ // Change the offset used to compute the CFA.
+ case DW_CFA_def_cfa_offset:
+ if (!ParseOperands("o", &ops) ||
+ !DoDefCFAOffset(ops.offset))
+ return false;
+ break;
+
+ // Change the offset used to compute the CFA.
+ case DW_CFA_def_cfa_offset_sf:
+ if (!ParseOperands("s", &ops) ||
+ !DoDefCFAOffset(ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Specify an expression whose value is the CFA.
+ case DW_CFA_def_cfa_expression: {
+ if (!ParseOperands("e", &ops))
+ return false;
+ Rule *rule = new ValExpressionRule(ops.expression);
+ rules_.SetCFARule(rule);
+ if (!rule->Handle(handler_, address_, Handler::kCFARegister))
+ return false;
+ break;
+ }
+
+ // The register's value cannot be recovered.
+ case DW_CFA_undefined: {
+ if (!ParseOperands("r", &ops) ||
+ !DoRule(ops.register_number, new UndefinedRule()))
+ return false;
+ break;
+ }
+
+ // The register's value is unchanged from its value in the caller.
+ case DW_CFA_same_value: {
+ if (!ParseOperands("r", &ops) ||
+ !DoRule(ops.register_number, new SameValueRule()))
+ return false;
+ break;
+ }
+
+ // Find a register at an offset from the CFA.
+ case DW_CFA_offset_extended:
+ if (!ParseOperands("ro", &ops) ||
+ !DoOffset(ops.register_number,
+ ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register is saved at an offset from the CFA.
+ case DW_CFA_offset_extended_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoOffset(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register is saved at an offset from the CFA.
+ case DW_CFA_GNU_negative_offset_extended:
+ if (!ParseOperands("ro", &ops) ||
+ !DoOffset(ops.register_number,
+ -ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register's value is the sum of the CFA plus an offset.
+ case DW_CFA_val_offset:
+ if (!ParseOperands("ro", &ops) ||
+ !DoValOffset(ops.register_number,
+ ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register's value is the sum of the CFA plus an offset.
+ case DW_CFA_val_offset_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoValOffset(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register has been saved in another register.
+ case DW_CFA_register: {
+ if (!ParseOperands("ro", &ops) ||
+ !DoRule(ops.register_number, new RegisterRule(ops.offset)))
+ return false;
+ break;
+ }
+
+ // An expression yields the address at which the register is saved.
+ case DW_CFA_expression: {
+ if (!ParseOperands("re", &ops) ||
+ !DoRule(ops.register_number, new ExpressionRule(ops.expression)))
+ return false;
+ break;
+ }
+
+ // An expression yields the caller's value for the register.
+ case DW_CFA_val_expression: {
+ if (!ParseOperands("re", &ops) ||
+ !DoRule(ops.register_number, new ValExpressionRule(ops.expression)))
+ return false;
+ break;
+ }
+
+ // Restore the rule established for a register by the CIE.
+ case DW_CFA_restore_extended:
+ if (!ParseOperands("r", &ops) ||
+ !DoRestore( ops.register_number))
+ return false;
+ break;
+
+ // Save the current set of rules on a stack.
+ case DW_CFA_remember_state:
+ if (!saved_rules_) {
+ saved_rules_ = new std::stack<RuleMap>();
+ }
+ saved_rules_->push(rules_);
+ break;
+
+ // Pop the current set of rules off the stack.
+ case DW_CFA_restore_state: {
+ if (!saved_rules_ || saved_rules_->empty()) {
+ reporter_->EmptyStateStack(entry_->offset, entry_->kind,
+ CursorOffset());
+ return false;
+ }
+ const RuleMap &new_rules = saved_rules_->top();
+ if (rules_.CFARule() && !new_rules.CFARule()) {
+ reporter_->ClearingCFARule(entry_->offset, entry_->kind,
+ CursorOffset());
+ return false;
+ }
+ rules_.HandleTransitionTo(handler_, address_, new_rules);
+ rules_ = new_rules;
+ saved_rules_->pop();
+ break;
+ }
+
+ // No operation. (Padding instruction.)
+ case DW_CFA_nop:
+ break;
+
+ // A SPARC register window save: Registers 8 through 15 (%o0-%o7)
+ // are saved in registers 24 through 31 (%i0-%i7), and registers
+ // 16 through 31 (%l0-%l7 and %i0-%i7) are saved at CFA offsets
+ // (0-15 * the register size). The register numbers must be
+ // hard-coded. A GNU extension, and not a pretty one.
+ case DW_CFA_GNU_window_save: {
+ // Save %o0-%o7 in %i0-%i7.
+ for (int i = 8; i < 16; i++)
+ if (!DoRule(i, new RegisterRule(i + 16)))
+ return false;
+ // Save %l0-%l7 and %i0-%i7 at the CFA.
+ for (int i = 16; i < 32; i++)
+ // Assume that the byte reader's address size is the same as
+ // the architecture's register size. !@#%*^ hilarious.
+ if (!DoRule(i, new OffsetRule(Handler::kCFARegister,
+ (i - 16) * reader_->AddressSize())))
+ return false;
+ break;
+ }
+
+ // I'm not sure what this is. GDB doesn't use it for unwinding.
+ case DW_CFA_GNU_args_size:
+ if (!ParseOperands("o", &ops)) return false;
+ break;
+
+ // An opcode we don't recognize.
+ default: {
+ reporter_->BadInstruction(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool CallFrameInfo::State::DoDefCFA(unsigned base_register, long offset) {
+ Rule *rule = new ValOffsetRule(base_register, offset);
+ rules_.SetCFARule(rule);
+ return rule->Handle(handler_, address_, Handler::kCFARegister);
+}
+
+bool CallFrameInfo::State::DoDefCFAOffset(long offset) {
+ Rule *cfa_rule = rules_.CFARule();
+ if (!cfa_rule) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ cfa_rule->SetOffset(offset);
+ return cfa_rule->Handle(handler_, address_, Handler::kCFARegister);
+}
+
+bool CallFrameInfo::State::DoRule(unsigned reg, Rule *rule) {
+ rules_.SetRegisterRule(reg, rule);
+ return rule->Handle(handler_, address_, reg);
+}
+
+bool CallFrameInfo::State::DoOffset(unsigned reg, long offset) {
+ if (!rules_.CFARule()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ return DoRule(reg,
+ new OffsetRule(Handler::kCFARegister, offset));
+}
+
+bool CallFrameInfo::State::DoValOffset(unsigned reg, long offset) {
+ if (!rules_.CFARule()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ return DoRule(reg,
+ new ValOffsetRule(Handler::kCFARegister, offset));
+}
+
+bool CallFrameInfo::State::DoRestore(unsigned reg) {
+ // DW_CFA_restore and DW_CFA_restore_extended don't make sense in a CIE.
+ if (entry_->kind == kCIE) {
+ reporter_->RestoreInCIE(entry_->offset, CursorOffset());
+ return false;
+ }
+ Rule *rule = cie_rules_.RegisterRule(reg);
+ if (!rule) {
+ // This isn't really the right thing to do, but since CFI generally
+ // only mentions callee-saves registers, and GCC's convention for
+ // callee-saves registers is that they are unchanged, it's a good
+ // approximation.
+ rule = new SameValueRule();
+ }
+ return DoRule(reg, rule);
+}
+
+bool CallFrameInfo::ReadEntryPrologue(const char *cursor, Entry *entry) {
+ const char *buffer_end = buffer_ + buffer_length_;
+
+ // Initialize enough of ENTRY for use in error reporting.
+ entry->offset = cursor - buffer_;
+ entry->start = cursor;
+ entry->kind = kUnknown;
+ entry->end = NULL;
+
+ // Read the initial length. This sets reader_'s offset size.
+ size_t length_size;
+ uint64 length = reader_->ReadInitialLength(cursor, &length_size);
+ if (length_size > size_t(buffer_end - cursor))
+ return ReportIncomplete(entry);
+ cursor += length_size;
+
+ // In a .eh_frame section, a length of zero marks the end of the series
+ // of entries.
+ if (length == 0 && eh_frame_) {
+ entry->kind = kTerminator;
+ entry->end = cursor;
+ return true;
+ }
+
+ // Validate the length.
+ if (length > size_t(buffer_end - cursor))
+ return ReportIncomplete(entry);
+
+ // The length is the number of bytes after the initial length field;
+ // we have that position handy at this point, so compute the end
+ // now. (If we're parsing 64-bit-offset DWARF on a 32-bit machine,
+ // and the length didn't fit in a size_t, we would have rejected it
+ // above.)
+ entry->end = cursor + length;
+
+ // Parse the next field: either the offset of a CIE or a CIE id.
+ size_t offset_size = reader_->OffsetSize();
+ if (offset_size > size_t(entry->end - cursor)) return ReportIncomplete(entry);
+ entry->id = reader_->ReadOffset(cursor);
+
+ // Don't advance cursor past id field yet; in .eh_frame data we need
+ // the id's position to compute the section offset of an FDE's CIE.
+
+ // Now we can decide what kind of entry this is.
+ if (eh_frame_) {
+ // In .eh_frame data, an ID of zero marks the entry as a CIE, and
+ // anything else is an offset from the id field of the FDE to the start
+ // of the CIE.
+ if (entry->id == 0) {
+ entry->kind = kCIE;
+ } else {
+ entry->kind = kFDE;
+ // Turn the offset from the id into an offset from the buffer's start.
+ entry->id = (cursor - buffer_) - entry->id;
+ }
+ } else {
+ // In DWARF CFI data, an ID of ~0 (of the appropriate width, given the
+ // offset size for the entry) marks the entry as a CIE, and anything
+ // else is the offset of the CIE from the beginning of the section.
+ if (offset_size == 4)
+ entry->kind = (entry->id == 0xffffffff) ? kCIE : kFDE;
+ else {
+ MOZ_ASSERT(offset_size == 8);
+ entry->kind = (entry->id == 0xffffffffffffffffULL) ? kCIE : kFDE;
+ }
+ }
+
+ // Now advance cursor past the id.
+ cursor += offset_size;
+
+ // The fields specific to this kind of entry start here.
+ entry->fields = cursor;
+
+ entry->cie = NULL;
+
+ return true;
+}
+
+bool CallFrameInfo::ReadCIEFields(CIE *cie) {
+ const char *cursor = cie->fields;
+ size_t len;
+
+ MOZ_ASSERT(cie->kind == kCIE);
+
+ // Prepare for early exit.
+ cie->version = 0;
+ cie->augmentation.clear();
+ cie->code_alignment_factor = 0;
+ cie->data_alignment_factor = 0;
+ cie->return_address_register = 0;
+ cie->has_z_augmentation = false;
+ cie->pointer_encoding = DW_EH_PE_absptr;
+ cie->instructions = 0;
+
+ // Parse the version number.
+ if (cie->end - cursor < 1)
+ return ReportIncomplete(cie);
+ cie->version = reader_->ReadOneByte(cursor);
+ cursor++;
+
+ // If we don't recognize the version, we can't parse any more fields of the
+ // CIE. For DWARF CFI, we handle versions 1 through 3 (there was never a
+ // version 2 of CFI data). For .eh_frame, we handle versions 1 and 3 as well;
+ // the difference between those versions seems to be the same as for
+ // .debug_frame.
+ if (cie->version < 1 || cie->version > 3) {
+ reporter_->UnrecognizedVersion(cie->offset, cie->version);
+ return false;
+ }
+
+ const char *augmentation_start = cursor;
+ const void *augmentation_end =
+ memchr(augmentation_start, '\0', cie->end - augmentation_start);
+ if (! augmentation_end) return ReportIncomplete(cie);
+ cursor = static_cast<const char *>(augmentation_end);
+ cie->augmentation = string(augmentation_start,
+ cursor - augmentation_start);
+ // Skip the terminating '\0'.
+ cursor++;
+
+ // Is this CFI augmented?
+ if (!cie->augmentation.empty()) {
+ // Is it an augmentation we recognize?
+ if (cie->augmentation[0] == DW_Z_augmentation_start) {
+ // Linux C++ ABI 'z' augmentation, used for exception handling data.
+ cie->has_z_augmentation = true;
+ } else {
+ // Not an augmentation we recognize. Augmentations can have arbitrary
+ // effects on the form of rest of the content, so we have to give up.
+ reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
+ return false;
+ }
+ }
+
+ // Parse the code alignment factor.
+ cie->code_alignment_factor = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+
+ // Parse the data alignment factor.
+ cie->data_alignment_factor = reader_->ReadSignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+
+ // Parse the return address register. This is a ubyte in version 1, and
+ // a ULEB128 in version 3.
+ if (cie->version == 1) {
+ if (cursor >= cie->end) return ReportIncomplete(cie);
+ cie->return_address_register = uint8(*cursor++);
+ } else {
+ cie->return_address_register = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+ }
+
+ // If we have a 'z' augmentation string, find the augmentation data and
+ // use the augmentation string to parse it.
+ if (cie->has_z_augmentation) {
+ uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len + data_size)
+ return ReportIncomplete(cie);
+ cursor += len;
+ const char *data = cursor;
+ cursor += data_size;
+ const char *data_end = cursor;
+
+ cie->has_z_lsda = false;
+ cie->has_z_personality = false;
+ cie->has_z_signal_frame = false;
+
+ // Walk the augmentation string, and extract values from the
+ // augmentation data as the string directs.
+ for (size_t i = 1; i < cie->augmentation.size(); i++) {
+ switch (cie->augmentation[i]) {
+ case DW_Z_has_LSDA:
+ // The CIE's augmentation data holds the language-specific data
+ // area pointer's encoding, and the FDE's augmentation data holds
+ // the pointer itself.
+ cie->has_z_lsda = true;
+ // Fetch the LSDA encoding from the augmentation data.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->lsda_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->lsda_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset, cie->lsda_encoding);
+ return false;
+ }
+ // Don't check if the encoding is usable here --- we haven't
+ // read the FDE's fields yet, so we're not prepared for
+ // DW_EH_PE_funcrel, although that's a fine encoding for the
+ // LSDA to use, since it appears in the FDE.
+ break;
+
+ case DW_Z_has_personality_routine:
+ // The CIE's augmentation data holds the personality routine
+ // pointer's encoding, followed by the pointer itself.
+ cie->has_z_personality = true;
+ // Fetch the personality routine pointer's encoding from the
+ // augmentation data.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->personality_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->personality_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset,
+ cie->personality_encoding);
+ return false;
+ }
+ if (!reader_->UsableEncoding(cie->personality_encoding)) {
+ reporter_->UnusablePointerEncoding(cie->offset,
+ cie->personality_encoding);
+ return false;
+ }
+ // Fetch the personality routine's pointer itself from the data.
+ cie->personality_address =
+ reader_->ReadEncodedPointer(data, cie->personality_encoding,
+ &len);
+ if (len > size_t(data_end - data))
+ return ReportIncomplete(cie);
+ data += len;
+ break;
+
+ case DW_Z_has_FDE_address_encoding:
+ // The CIE's augmentation data holds the pointer encoding to use
+ // for addresses in the FDE.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->pointer_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->pointer_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset,
+ cie->pointer_encoding);
+ return false;
+ }
+ if (!reader_->UsableEncoding(cie->pointer_encoding)) {
+ reporter_->UnusablePointerEncoding(cie->offset,
+ cie->pointer_encoding);
+ return false;
+ }
+ break;
+
+ case DW_Z_is_signal_trampoline:
+ // Frames using this CIE are signal delivery frames.
+ cie->has_z_signal_frame = true;
+ break;
+
+ default:
+ // An augmentation we don't recognize.
+ reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
+ return false;
+ }
+ }
+ }
+
+ // The CIE's instructions start here.
+ cie->instructions = cursor;
+
+ return true;
+}
+
+bool CallFrameInfo::ReadFDEFields(FDE *fde) {
+ const char *cursor = fde->fields;
+ size_t size;
+
+ fde->address = reader_->ReadEncodedPointer(cursor, fde->cie->pointer_encoding,
+ &size);
+ if (size > size_t(fde->end - cursor))
+ return ReportIncomplete(fde);
+ cursor += size;
+ reader_->SetFunctionBase(fde->address);
+
+ // For the length, we strip off the upper nybble of the encoding used for
+ // the starting address.
+ DwarfPointerEncoding length_encoding =
+ DwarfPointerEncoding(fde->cie->pointer_encoding & 0x0f);
+ fde->size = reader_->ReadEncodedPointer(cursor, length_encoding, &size);
+ if (size > size_t(fde->end - cursor))
+ return ReportIncomplete(fde);
+ cursor += size;
+
+ // If the CIE has a 'z' augmentation string, then augmentation data
+ // appears here.
+ if (fde->cie->has_z_augmentation) {
+ uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &size);
+ if (size_t(fde->end - cursor) < size + data_size)
+ return ReportIncomplete(fde);
+ cursor += size;
+
+ // In the abstract, we should walk the augmentation string, and extract
+ // items from the FDE's augmentation data as we encounter augmentation
+ // string characters that specify their presence: the ordering of items
+ // in the augmentation string determines the arrangement of values in
+ // the augmentation data.
+ //
+ // In practice, there's only ever one value in FDE augmentation data
+ // that we support --- the LSDA pointer --- and we have to bail if we
+ // see any unrecognized augmentation string characters. So if there is
+ // anything here at all, we know what it is, and where it starts.
+ if (fde->cie->has_z_lsda) {
+ // Check whether the LSDA's pointer encoding is usable now: only once
+ // we've parsed the FDE's starting address do we call reader_->
+ // SetFunctionBase, so that the DW_EH_PE_funcrel encoding becomes
+ // usable.
+ if (!reader_->UsableEncoding(fde->cie->lsda_encoding)) {
+ reporter_->UnusablePointerEncoding(fde->cie->offset,
+ fde->cie->lsda_encoding);
+ return false;
+ }
+
+ fde->lsda_address =
+ reader_->ReadEncodedPointer(cursor, fde->cie->lsda_encoding, &size);
+ if (size > data_size)
+ return ReportIncomplete(fde);
+ // Ideally, we would also complain here if there were unconsumed
+ // augmentation data.
+ }
+
+ cursor += data_size;
+ }
+
+ // The FDE's instructions start after those.
+ fde->instructions = cursor;
+
+ return true;
+}
+
+bool CallFrameInfo::Start() {
+ const char *buffer_end = buffer_ + buffer_length_;
+ const char *cursor;
+ bool all_ok = true;
+ const char *entry_end;
+ bool ok;
+
+ // Traverse all the entries in buffer_, skipping CIEs and offering
+ // FDEs to the handler.
+ for (cursor = buffer_; cursor < buffer_end;
+ cursor = entry_end, all_ok = all_ok && ok) {
+ FDE fde;
+
+ // Make it easy to skip this entry with 'continue': assume that
+ // things are not okay until we've checked all the data, and
+ // prepare the address of the next entry.
+ ok = false;
+
+ // Read the entry's prologue.
+ if (!ReadEntryPrologue(cursor, &fde)) {
+ if (!fde.end) {
+ // If we couldn't even figure out this entry's extent, then we
+ // must stop processing entries altogether.
+ all_ok = false;
+ break;
+ }
+ entry_end = fde.end;
+ continue;
+ }
+
+ // The next iteration picks up after this entry.
+ entry_end = fde.end;
+
+ // Did we see an .eh_frame terminating mark?
+ if (fde.kind == kTerminator) {
+ // If there appears to be more data left in the section after the
+ // terminating mark, warn the user. But this is just a warning;
+ // we leave all_ok true.
+ if (fde.end < buffer_end) reporter_->EarlyEHTerminator(fde.offset);
+ break;
+ }
+
+ // In this loop, we skip CIEs. We only parse them fully when we
+ // parse an FDE that refers to them. This limits our memory
+ // consumption (beyond the buffer itself) to that needed to
+ // process the largest single entry.
+ if (fde.kind != kFDE) {
+ ok = true;
+ continue;
+ }
+
+ // Validate the CIE pointer.
+ if (fde.id > buffer_length_) {
+ reporter_->CIEPointerOutOfRange(fde.offset, fde.id);
+ continue;
+ }
+
+ CIE cie;
+
+ // Parse this FDE's CIE header.
+ if (!ReadEntryPrologue(buffer_ + fde.id, &cie))
+ continue;
+ // This had better be an actual CIE.
+ if (cie.kind != kCIE) {
+ reporter_->BadCIEId(fde.offset, fde.id);
+ continue;
+ }
+ if (!ReadCIEFields(&cie))
+ continue;
+
+ // We now have the values that govern both the CIE and the FDE.
+ cie.cie = &cie;
+ fde.cie = &cie;
+
+ // Parse the FDE's header.
+ if (!ReadFDEFields(&fde))
+ continue;
+
+ // Call Entry to ask the consumer if they're interested.
+ if (!handler_->Entry(fde.offset, fde.address, fde.size,
+ cie.version, cie.augmentation,
+ cie.return_address_register)) {
+ // The handler isn't interested in this entry. That's not an error.
+ ok = true;
+ continue;
+ }
+
+ if (cie.has_z_augmentation) {
+ // Report the personality routine address, if we have one.
+ if (cie.has_z_personality) {
+ if (!handler_
+ ->PersonalityRoutine(cie.personality_address,
+ IsIndirectEncoding(cie.personality_encoding)))
+ continue;
+ }
+
+ // Report the language-specific data area address, if we have one.
+ if (cie.has_z_lsda) {
+ if (!handler_
+ ->LanguageSpecificDataArea(fde.lsda_address,
+ IsIndirectEncoding(cie.lsda_encoding)))
+ continue;
+ }
+
+ // If this is a signal-handling frame, report that.
+ if (cie.has_z_signal_frame) {
+ if (!handler_->SignalHandler())
+ continue;
+ }
+ }
+
+ // Interpret the CIE's instructions, and then the FDE's instructions.
+ State state(reader_, handler_, reporter_, fde.address);
+ ok = state.InterpretCIE(cie) && state.InterpretFDE(fde);
+
+ // Tell the ByteReader that the function start address from the
+ // FDE header is no longer valid.
+ reader_->ClearFunctionBase();
+
+ // Report the end of the entry.
+ handler_->End();
+ }
+
+ return all_ok;
+}
+
+const char *CallFrameInfo::KindName(EntryKind kind) {
+ if (kind == CallFrameInfo::kUnknown)
+ return "entry";
+ else if (kind == CallFrameInfo::kCIE)
+ return "common information entry";
+ else if (kind == CallFrameInfo::kFDE)
+ return "frame description entry";
+ else {
+ MOZ_ASSERT (kind == CallFrameInfo::kTerminator);
+ return ".eh_frame sequence terminator";
+ }
+}
+
+bool CallFrameInfo::ReportIncomplete(Entry *entry) {
+ reporter_->Incomplete(entry->offset, entry->kind);
+ return false;
+}
+
+void CallFrameInfo::Reporter::Incomplete(uint64 offset,
+ CallFrameInfo::EntryKind kind) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI %s at offset 0x%llx in '%s': entry ends early\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str());
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::EarlyEHTerminator(uint64 offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI at offset 0x%llx in '%s': saw end-of-data marker"
+ " before end of section contents\n",
+ filename_.c_str(), offset, section_.c_str());
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::CIEPointerOutOfRange(uint64 offset,
+ uint64 cie_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE pointer is out of range: 0x%llx\n",
+ filename_.c_str(), offset, section_.c_str(), cie_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::BadCIEId(uint64 offset, uint64 cie_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE pointer does not point to a CIE: 0x%llx\n",
+ filename_.c_str(), offset, section_.c_str(), cie_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::UnrecognizedVersion(uint64 offset, int version) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unrecognized version: %d\n",
+ filename_.c_str(), offset, section_.c_str(), version);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::UnrecognizedAugmentation(uint64 offset,
+ const string &aug) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unrecognized augmentation: '%s'\n",
+ filename_.c_str(), offset, section_.c_str(), aug.c_str());
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::InvalidPointerEncoding(uint64 offset,
+ uint8 encoding) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " 'z' augmentation specifies invalid pointer encoding: "
+ "0x%02x\n",
+ filename_.c_str(), offset, section_.c_str(), encoding);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::UnusablePointerEncoding(uint64 offset,
+ uint8 encoding) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " 'z' augmentation specifies a pointer encoding for which"
+ " we have no base address: 0x%02x\n",
+ filename_.c_str(), offset, section_.c_str(), encoding);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::RestoreInCIE(uint64 offset, uint64 insn_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " the DW_CFA_restore instruction at offset 0x%llx"
+ " cannot be used in a common information entry\n",
+ filename_.c_str(), offset, section_.c_str(), insn_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::BadInstruction(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the instruction at offset 0x%llx is unrecognized\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind),
+ offset, section_.c_str(), insn_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::NoCFARule(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the instruction at offset 0x%llx assumes that a CFA rule "
+ "has been set, but none has been set\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::EmptyStateStack(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the DW_CFA_restore_state instruction at offset 0x%llx"
+ " should pop a saved state from the stack, but the stack "
+ "is empty\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+ log_(buf);
+}
+
+void CallFrameInfo::Reporter::ClearingCFARule(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the DW_CFA_restore_state instruction at offset 0x%llx"
+ " would clear the CFA rule in effect\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+ log_(buf);
+}
+
+
+unsigned int DwarfCFIToModule::RegisterNames::I386() {
+ /*
+ 8 "$eax", "$ecx", "$edx", "$ebx", "$esp", "$ebp", "$esi", "$edi",
+ 3 "$eip", "$eflags", "$unused1",
+ 8 "$st0", "$st1", "$st2", "$st3", "$st4", "$st5", "$st6", "$st7",
+ 2 "$unused2", "$unused3",
+ 8 "$xmm0", "$xmm1", "$xmm2", "$xmm3", "$xmm4", "$xmm5", "$xmm6", "$xmm7",
+ 8 "$mm0", "$mm1", "$mm2", "$mm3", "$mm4", "$mm5", "$mm6", "$mm7",
+ 3 "$fcw", "$fsw", "$mxcsr",
+ 8 "$es", "$cs", "$ss", "$ds", "$fs", "$gs", "$unused4", "$unused5",
+ 2 "$tr", "$ldtr"
+ */
+ return 8 + 3 + 8 + 2 + 8 + 8 + 3 + 8 + 2;
+}
+
+unsigned int DwarfCFIToModule::RegisterNames::X86_64() {
+ /*
+ 8 "$rax", "$rdx", "$rcx", "$rbx", "$rsi", "$rdi", "$rbp", "$rsp",
+ 8 "$r8", "$r9", "$r10", "$r11", "$r12", "$r13", "$r14", "$r15",
+ 1 "$rip",
+ 8 "$xmm0","$xmm1","$xmm2", "$xmm3", "$xmm4", "$xmm5", "$xmm6", "$xmm7",
+ 8 "$xmm8","$xmm9","$xmm10","$xmm11","$xmm12","$xmm13","$xmm14","$xmm15",
+ 8 "$st0", "$st1", "$st2", "$st3", "$st4", "$st5", "$st6", "$st7",
+ 8 "$mm0", "$mm1", "$mm2", "$mm3", "$mm4", "$mm5", "$mm6", "$mm7",
+ 1 "$rflags",
+ 8 "$es", "$cs", "$ss", "$ds", "$fs", "$gs", "$unused1", "$unused2",
+ 4 "$fs.base", "$gs.base", "$unused3", "$unused4",
+ 2 "$tr", "$ldtr",
+ 3 "$mxcsr", "$fcw", "$fsw"
+ */
+ return 8 + 8 + 1 + 8 + 8 + 8 + 8 + 1 + 8 + 4 + 2 + 3;
+}
+
+// Per ARM IHI 0040A, section 3.1
+unsigned int DwarfCFIToModule::RegisterNames::ARM() {
+ /*
+ 8 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
+ 8 "r8", "r9", "r10", "r11", "r12", "sp", "lr", "pc",
+ 8 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
+ 8 "fps", "cpsr", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
+ 8 "s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15",
+ 8 "s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23",
+ 8 "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31",
+ 8 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7"
+ */
+ return 13 * 8;
+}
+
+// See prototype for comments.
+int32_t parseDwarfExpr(Summariser* summ, const ByteReader* reader,
+ string expr, bool debug,
+ bool pushCfaAtStart, bool derefAtEnd)
+{
+ const char* cursor = expr.c_str();
+ const char* end1 = cursor + expr.length();
+
+ char buf[100];
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW << DwarfExpr, len is %d\n",
+ (int)(end1 - cursor));
+ summ->Log(buf);
+ }
+
+ // Add a marker for the start of this expression. In it, indicate
+ // whether or not the CFA should be pushed onto the stack prior to
+ // evaluation.
+ int32_t start_ix
+ = summ->AddPfxInstr(PfxInstr(PX_Start, pushCfaAtStart ? 1 : 0));
+ MOZ_ASSERT(start_ix >= 0);
+
+ while (cursor < end1) {
+
+ uint8 opc = reader->ReadOneByte(cursor);
+ cursor++;
+
+ const char* nm = nullptr;
+ PfxExprOp pxop = PX_End;
+
+ switch (opc) {
+
+ case DW_OP_lit0 ... DW_OP_lit31: {
+ int32_t simm32 = (int32_t)(opc - DW_OP_lit0);
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW DW_OP_lit%d\n", (int)simm32);
+ summ->Log(buf);
+ }
+ (void) summ->AddPfxInstr(PfxInstr(PX_SImm32, simm32));
+ break;
+ }
+
+ case DW_OP_breg0 ... DW_OP_breg31: {
+ size_t len;
+ int64_t n = reader->ReadSignedLEB128(cursor, &len);
+ cursor += len;
+ DW_REG_NUMBER reg = (DW_REG_NUMBER)(opc - DW_OP_breg0);
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW DW_OP_breg%d %lld\n",
+ (int)reg, (long long int)n);
+ summ->Log(buf);
+ }
+ // PfxInstr only allows a 32 bit signed offset. So we
+ // must fail if the immediate is out of range.
+ if (n < INT32_MIN || INT32_MAX < n)
+ goto fail;
+ (void) summ->AddPfxInstr(PfxInstr(PX_DwReg, reg));
+ (void) summ->AddPfxInstr(PfxInstr(PX_SImm32, (int32_t)n));
+ (void) summ->AddPfxInstr(PfxInstr(PX_Add));
+ break;
+ }
+
+ case DW_OP_const4s: {
+ uint64_t u64 = reader->ReadFourBytes(cursor);
+ cursor += 4;
+ // u64 is guaranteed by |ReadFourBytes| to be in the
+ // range 0 .. FFFFFFFF inclusive. But to be safe:
+ uint32_t u32 = (uint32_t)(u64 & 0xFFFFFFFF);
+ int32_t s32 = (int32_t)u32;
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW DW_OP_const4s %d\n", (int)s32);
+ summ->Log(buf);
+ }
+ (void) summ->AddPfxInstr(PfxInstr(PX_SImm32, s32));
+ break;
+ }
+
+ case DW_OP_deref: nm = "deref"; pxop = PX_Deref; goto no_operands;
+ case DW_OP_and: nm = "and"; pxop = PX_And; goto no_operands;
+ case DW_OP_plus: nm = "plus"; pxop = PX_Add; goto no_operands;
+ case DW_OP_minus: nm = "minus"; pxop = PX_Sub; goto no_operands;
+ case DW_OP_shl: nm = "shl"; pxop = PX_Shl; goto no_operands;
+ case DW_OP_ge: nm = "ge"; pxop = PX_CmpGES; goto no_operands;
+ no_operands:
+ MOZ_ASSERT(nm && pxop != PX_End);
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW DW_OP_%s\n", nm);
+ summ->Log(buf);
+ }
+ (void) summ->AddPfxInstr(PfxInstr(pxop));
+ break;
+
+ default:
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW unknown opc %d\n", (int)opc);
+ summ->Log(buf);
+ }
+ goto fail;
+
+ } // switch (opc)
+
+ } // while (cursor < end1)
+
+ MOZ_ASSERT(cursor >= end1);
+
+ if (cursor > end1) {
+ // We overran the Dwarf expression. Give up.
+ goto fail;
+ }
+
+ // For DW_CFA_expression, what the expression denotes is the address
+ // of where the previous value is located. The caller of this routine
+ // may therefore request one last dereference before the end marker is
+ // inserted.
+ if (derefAtEnd) {
+ (void) summ->AddPfxInstr(PfxInstr(PX_Deref));
+ }
+
+ // Insert an end marker, and declare success.
+ (void) summ->AddPfxInstr(PfxInstr(PX_End));
+ if (debug) {
+ SprintfLiteral(buf, "LUL.DW conversion of dwarf expression succeeded, "
+ "ix = %d\n", (int)start_ix);
+ summ->Log(buf);
+ summ->Log("LUL.DW >>\n");
+ }
+ return start_ix;
+
+ fail:
+ if (debug) {
+ summ->Log("LUL.DW conversion of dwarf expression failed\n");
+ summ->Log("LUL.DW >>\n");
+ }
+ return -1;
+}
+
+
+bool DwarfCFIToModule::Entry(size_t offset, uint64 address, uint64 length,
+ uint8 version, const string &augmentation,
+ unsigned return_address) {
+ if (DEBUG_DWARF) {
+ char buf[100];
+ SprintfLiteral(buf, "LUL.DW DwarfCFIToModule::Entry 0x%llx,+%lld\n",
+ address, length);
+ summ_->Log(buf);
+ }
+
+ summ_->Entry(address, length);
+
+ // If dwarf2reader::CallFrameInfo can handle this version and
+ // augmentation, then we should be okay with that, so there's no
+ // need to check them here.
+
+ // Get ready to collect entries.
+ 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_ < num_dw_regs_) {
+ summ_->Rule(address, return_address_, NODEREF, return_address, 0);
+ }
+
+ return true;
+}
+
+const UniqueString* DwarfCFIToModule::RegisterName(int i) {
+ if (i < 0) {
+ MOZ_ASSERT(i == kCFARegister);
+ return usu_->ToUniqueString(".cfa");
+ }
+ unsigned reg = i;
+ if (reg == return_address_)
+ return usu_->ToUniqueString(".ra");
+
+ char buf[30];
+ SprintfLiteral(buf, "dwarf_reg_%u", reg);
+ return usu_->ToUniqueString(buf);
+}
+
+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) {
+ if (DEBUG_DWARF) {
+ char buf[100];
+ SprintfLiteral(buf, "LUL.DW 0x%llx: old r%d = Same\n", address, reg);
+ summ_->Log(buf);
+ }
+ // reg + 0
+ summ_->Rule(address, reg, NODEREF, reg, 0);
+ return true;
+}
+
+bool DwarfCFIToModule::OffsetRule(uint64 address, int reg,
+ int base_register, long offset) {
+ if (DEBUG_DWARF) {
+ char buf[100];
+ SprintfLiteral(buf, "LUL.DW 0x%llx: old r%d = *(r%d + %ld)\n",
+ address, reg, base_register, offset);
+ summ_->Log(buf);
+ }
+ // *(base_register + offset)
+ summ_->Rule(address, reg, DEREF, base_register, offset);
+ return true;
+}
+
+bool DwarfCFIToModule::ValOffsetRule(uint64 address, int reg,
+ int base_register, long offset) {
+ if (DEBUG_DWARF) {
+ char buf[100];
+ SprintfLiteral(buf, "LUL.DW 0x%llx: old r%d = r%d + %ld\n",
+ address, reg, base_register, offset);
+ summ_->Log(buf);
+ }
+ // base_register + offset
+ summ_->Rule(address, reg, NODEREF, base_register, offset);
+ return true;
+}
+
+bool DwarfCFIToModule::RegisterRule(uint64 address, int reg,
+ int base_register) {
+ if (DEBUG_DWARF) {
+ char buf[100];
+ SprintfLiteral(buf, "LUL.DW 0x%llx: old r%d = r%d\n",
+ address, reg, base_register);
+ summ_->Log(buf);
+ }
+ // base_register + 0
+ summ_->Rule(address, reg, NODEREF, base_register, 0);
+ return true;
+}
+
+bool DwarfCFIToModule::ExpressionRule(uint64 address, int reg,
+ const string &expression)
+{
+ bool debug = !!DEBUG_DWARF;
+ int32_t start_ix = parseDwarfExpr(summ_, reader_, expression, debug,
+ true/*pushCfaAtStart*/,
+ true/*derefAtEnd*/);
+ if (start_ix >= 0) {
+ summ_->Rule(address, reg, PFXEXPR, 0, start_ix);
+ } else {
+ // Parsing of the Dwarf expression failed. Treat this as a
+ // non-fatal error, hence return |true| even on this path.
+ reporter_->ExpressionCouldNotBeSummarised(entry_offset_, RegisterName(reg));
+ }
+ return true;
+}
+
+bool DwarfCFIToModule::ValExpressionRule(uint64 address, int reg,
+ const string &expression)
+{
+ bool debug = !!DEBUG_DWARF;
+ int32_t start_ix = parseDwarfExpr(summ_, reader_, expression, debug,
+ true/*pushCfaAtStart*/,
+ false/*!derefAtEnd*/);
+ if (start_ix >= 0) {
+ summ_->Rule(address, reg, PFXEXPR, 0, start_ix);
+ } else {
+ // Parsing of the Dwarf expression failed. Treat this as a
+ // non-fatal error, hence return |true| even on this path.
+ reporter_->ExpressionCouldNotBeSummarised(entry_offset_, RegisterName(reg));
+ }
+ return true;
+}
+
+bool DwarfCFIToModule::End() {
+ //module_->AddStackFrameEntry(entry_);
+ if (DEBUG_DWARF) {
+ summ_->Log("LUL.DW DwarfCFIToModule::End()\n");
+ }
+ summ_->End();
+ return true;
+}
+
+void DwarfCFIToModule::Reporter::UndefinedNotSupported(
+ size_t offset,
+ const UniqueString* reg) {
+ char buf[300];
+ SprintfLiteral(buf, "DwarfCFIToModule::Reporter::UndefinedNotSupported()\n");
+ log_(buf);
+ //BPLOG(INFO) << file_ << ", section '" << section_
+ // << "': the call frame entry at offset 0x"
+ // << std::setbase(16) << offset << std::setbase(10)
+ // << " sets the rule for register '" << FromUniqueString(reg)
+ // << "' to 'undefined', but the Breakpad symbol file format cannot "
+ // << " express this";
+}
+
+// FIXME: move this somewhere sensible
+static bool is_power_of_2(uint64_t n)
+{
+ int i, nSetBits = 0;
+ for (i = 0; i < 8*(int)sizeof(n); i++) {
+ if ((n & ((uint64_t)1) << i) != 0)
+ nSetBits++;
+ }
+ return nSetBits <= 1;
+}
+
+void DwarfCFIToModule::Reporter::ExpressionCouldNotBeSummarised(
+ size_t offset,
+ const UniqueString* reg) {
+ static uint64_t n_complaints = 0; // This isn't threadsafe
+ n_complaints++;
+ if (!is_power_of_2(n_complaints))
+ return;
+ char buf[300];
+ SprintfLiteral(buf,
+ "DwarfCFIToModule::Reporter::"
+ "ExpressionCouldNotBeSummarised(shown %llu times)\n",
+ (unsigned long long int)n_complaints);
+ log_(buf);
+}
+
+} // namespace lul