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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 <stack>
+#include <string>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/Vector.h"
+
+#include "LulCommonExt.h"
+#include "LulDwarfInt.h"
+
+// Set this to 1 for verbose logging
+#define DEBUG_DWARF 0
+
+namespace lul {
+
+using std::pair;
+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. This is an 8-way sum-of-products
+// type. Excluding the INVALID variant, there is one subclass of this for
+// each '*Rule' member function in CallFrameInfo::Handler.
+//
+// This could logically be nested within State, but then the qualified names
+// get horrendous.
+
+class CallFrameInfo::Rule final {
+ public:
+ enum Tag {
+ INVALID,
+ Undefined,
+ SameValue,
+ Offset,
+ ValOffset,
+ Register,
+ Expression,
+ ValExpression
+ };
+
+ private:
+ // tag_ (below) indicates the form of the expression. There are 7 forms
+ // plus INVALID. All non-INVALID expressions denote a machine-word-sized
+ // value at unwind time. The description below assumes the presence of, at
+ // unwind time:
+ //
+ // * a function R, which takes a Dwarf register number and returns its value
+ // in the callee frame (the one we are unwinding out of).
+ //
+ // * a function EvalDwarfExpr, which evaluates a Dwarf expression.
+ //
+ // Register numbers are encoded using the target ABI's Dwarf
+ // register-numbering conventions. Except where otherwise noted, a register
+ // value may also be the special value CallFrameInfo::Handler::kCFARegister
+ // ("the CFA").
+ //
+ // The expression forms are represented using tag_, word1_ and word2_. The
+ // forms and denoted values are as follows:
+ //
+ // * INVALID: not a valid expression.
+ // valid fields: (none)
+ // denotes: no value
+ //
+ // * Undefined: denotes no value. This is used for a register whose value
+ // cannot be recovered.
+ // valid fields: (none)
+ // denotes: no value
+ //
+ // * SameValue: the register's value is the same as in the callee.
+ // valid fields: (none)
+ // denotes: R(the register that this Rule is associated with,
+ // not stored here)
+ //
+ // * Offset: the register's value is in memory at word2_ bytes away from
+ // Dwarf register number word1_. word2_ is interpreted as a *signed*
+ // offset.
+ // valid fields: word1_=DwarfReg, word2=Offset
+ // denotes: *(R(word1_) + word2_)
+ //
+ // * ValOffset: same as Offset, without the dereference.
+ // valid fields: word1_=DwarfReg, word2=Offset
+ // denotes: R(word1_) + word2_
+ //
+ // * Register: the register's value is in some other register,
+ // which may not be the CFA.
+ // valid fields: word1_=DwarfReg
+ // denotes: R(word1_)
+ //
+ // * Expression: the register's value is in memory at a location that can be
+ // computed from the Dwarf expression contained in the word2_ bytes
+ // starting at word1_. Note these locations are into the area of the .so
+ // temporarily mmaped info for debuginfo reading and have no validity once
+ // debuginfo reading has finished.
+ // valid fields: ExprStart=word1_, ExprLen=word2_
+ // denotes: *(EvalDwarfExpr(word1_, word2_))
+ //
+ // * ValExpression: same as Expression, without the dereference.
+ // valid fields: ExprStart=word1_, ExprLen=word2_
+ // denotes: EvalDwarfExpr(word1_, word2_)
+ //
+
+ // 3 words (or less) for representation. Unused word1_/word2_ fields must
+ // be set to zero.
+ Tag tag_;
+ uintptr_t word1_;
+ uintptr_t word2_;
+
+ // To ensure that word1_ can hold a pointer to an expression string.
+ static_assert(sizeof(const char*) <= sizeof(word1_));
+ // To ensure that word2_ can hold any string length or memory offset.
+ static_assert(sizeof(size_t) <= sizeof(word2_));
+
+ // This class denotes an 8-way sum-of-product type, and accessing invalid
+ // fields is meaningless. The accessors and constructors below enforce
+ // that.
+ bool isCanonical() const {
+ switch (tag_) {
+ case Tag::INVALID:
+ case Tag::Undefined:
+ case Tag::SameValue:
+ return word1_ == 0 && word2_ == 0;
+ case Tag::Offset:
+ case Tag::ValOffset:
+ return true;
+ case Tag::Register:
+ return word2_ == 0;
+ case Tag::Expression:
+ case Tag::ValExpression:
+ return true;
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ public:
+ Tag tag() const { return tag_; }
+ int dwreg() const {
+ switch (tag_) {
+ case Tag::Offset:
+ case Tag::ValOffset:
+ case Tag::Register:
+ return (int)word1_;
+ default:
+ MOZ_CRASH();
+ }
+ }
+ intptr_t offset() const {
+ switch (tag_) {
+ case Tag::Offset:
+ case Tag::ValOffset:
+ return (intptr_t)word2_;
+ default:
+ MOZ_CRASH();
+ }
+ }
+ ImageSlice expr() const {
+ switch (tag_) {
+ case Tag::Expression:
+ case Tag::ValExpression:
+ return ImageSlice((const char*)word1_, (size_t)word2_);
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // Constructor-y stuff
+ Rule() {
+ tag_ = Tag::INVALID;
+ word1_ = 0;
+ word2_ = 0;
+ }
+
+ static Rule mkINVALID() {
+ Rule r; // is initialised by Rule()
+ return r;
+ }
+ static Rule mkUndefinedRule() {
+ Rule r;
+ r.tag_ = Tag::Undefined;
+ r.word1_ = 0;
+ r.word2_ = 0;
+ return r;
+ }
+ static Rule mkSameValueRule() {
+ Rule r;
+ r.tag_ = Tag::SameValue;
+ r.word1_ = 0;
+ r.word2_ = 0;
+ return r;
+ }
+ static Rule mkOffsetRule(int dwreg, intptr_t offset) {
+ Rule r;
+ r.tag_ = Tag::Offset;
+ r.word1_ = (uintptr_t)dwreg;
+ r.word2_ = (uintptr_t)offset;
+ return r;
+ }
+ static Rule mkValOffsetRule(int dwreg, intptr_t offset) {
+ Rule r;
+ r.tag_ = Tag::ValOffset;
+ r.word1_ = (uintptr_t)dwreg;
+ r.word2_ = (uintptr_t)offset;
+ return r;
+ }
+ static Rule mkRegisterRule(int dwreg) {
+ Rule r;
+ r.tag_ = Tag::Register;
+ r.word1_ = (uintptr_t)dwreg;
+ r.word2_ = 0;
+ return r;
+ }
+ static Rule mkExpressionRule(ImageSlice expr) {
+ Rule r;
+ r.tag_ = Tag::Expression;
+ r.word1_ = (uintptr_t)expr.start_;
+ r.word2_ = (uintptr_t)expr.length_;
+ return r;
+ }
+ static Rule mkValExpressionRule(ImageSlice expr) {
+ Rule r;
+ r.tag_ = Tag::ValExpression;
+ r.word1_ = (uintptr_t)expr.start_;
+ r.word2_ = (uintptr_t)expr.length_;
+ return r;
+ }
+
+ // Misc
+ inline bool isVALID() const { return tag_ != Tag::INVALID; }
+
+ bool operator==(const Rule& rhs) const {
+ MOZ_ASSERT(isVALID() && rhs.isVALID());
+ MOZ_ASSERT(isCanonical());
+ MOZ_ASSERT(rhs.isCanonical());
+ if (tag_ != rhs.tag_) {
+ return false;
+ }
+ switch (tag_) {
+ case Tag::INVALID:
+ MOZ_CRASH();
+ case Tag::Undefined:
+ case Tag::SameValue:
+ return true;
+ case Tag::Offset:
+ case Tag::ValOffset:
+ return word1_ == rhs.word1_ && word2_ == rhs.word2_;
+ case Tag::Register:
+ return word1_ == rhs.word1_;
+ case Tag::Expression:
+ case Tag::ValExpression:
+ return expr() == rhs.expr();
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ bool operator!=(const Rule& rhs) const { return !(*this == rhs); }
+
+ // Tell HANDLER that, at ADDRESS in the program, REG can be
+ // recovered using this rule. If REG is kCFARegister, then this rule
+ // describes how to compute the canonical frame address. Return what the
+ // HANDLER member function returned.
+ bool Handle(Handler* handler, uint64 address, int reg) const {
+ MOZ_ASSERT(isVALID());
+ MOZ_ASSERT(isCanonical());
+ switch (tag_) {
+ case Tag::Undefined:
+ return handler->UndefinedRule(address, reg);
+ case Tag::SameValue:
+ return handler->SameValueRule(address, reg);
+ case Tag::Offset:
+ return handler->OffsetRule(address, reg, word1_, word2_);
+ case Tag::ValOffset:
+ return handler->ValOffsetRule(address, reg, word1_, word2_);
+ case Tag::Register:
+ return handler->RegisterRule(address, reg, word1_);
+ case Tag::Expression:
+ return handler->ExpressionRule(
+ address, reg, ImageSlice((const char*)word1_, (size_t)word2_));
+ case Tag::ValExpression:
+ return handler->ValExpressionRule(
+ address, reg, ImageSlice((const char*)word1_, (size_t)word2_));
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ void SetBaseRegister(unsigned reg) {
+ MOZ_ASSERT(isVALID());
+ MOZ_ASSERT(isCanonical());
+ switch (tag_) {
+ case Tag::ValOffset:
+ word1_ = reg;
+ break;
+ case Tag::Offset:
+ // 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.
+ // (fallthrough)
+ case Tag::Undefined:
+ case Tag::SameValue:
+ case Tag::Register:
+ case Tag::Expression:
+ case Tag::ValExpression:
+ // Do nothing
+ break;
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ void SetOffset(long long offset) {
+ MOZ_ASSERT(isVALID());
+ MOZ_ASSERT(isCanonical());
+ switch (tag_) {
+ case Tag::ValOffset:
+ word2_ = offset;
+ break;
+ case Tag::Offset:
+ // Same comment as in SetBaseRegister applies
+ // (fallthrough)
+ case Tag::Undefined:
+ case Tag::SameValue:
+ case Tag::Register:
+ case Tag::Expression:
+ case Tag::ValExpression:
+ // Do nothing
+ break;
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // For debugging only
+ string show() const {
+ char buf[100];
+ string s = "";
+ switch (tag_) {
+ case Tag::INVALID:
+ s = "INVALID";
+ break;
+ case Tag::Undefined:
+ s = "Undefined";
+ break;
+ case Tag::SameValue:
+ s = "SameValue";
+ break;
+ case Tag::Offset:
+ s = "Offset{..}";
+ break;
+ case Tag::ValOffset:
+ sprintf(buf, "ValOffset{reg=%d offs=%lld}", (int)word1_,
+ (long long int)word2_);
+ s = string(buf);
+ break;
+ case Tag::Register:
+ s = "Register{..}";
+ break;
+ case Tag::Expression:
+ s = "Expression{..}";
+ break;
+ case Tag::ValExpression:
+ s = "ValExpression{..}";
+ break;
+ default:
+ MOZ_CRASH();
+ }
+ return s;
+ }
+};
+
+// `RuleMapLowLevel` is a simple class that maps from `int` (register numbers)
+// to `Rule`. This is implemented as a vector of `<int, Rule>` pairs, with a
+// 12-element inline capacity. From a big-O perspective this is obviously a
+// terrible way to implement an associative map. This workload is however
+// quite special in that the maximum number of elements is normally 7 (on
+// x86_64-linux), and so this implementation is much faster than one based on
+// std::map with its attendant R-B-tree node allocation and balancing
+// overheads.
+//
+// An iterator that enumerates the mapping in increasing order of the `int`
+// keys is provided. This ordered iteration facility is required by
+// CallFrameInfo::RuleMap::HandleTransitionTo, which needs to iterate through
+// two such maps simultaneously and in-order so as to compare them.
+
+// All `Rule`s in the map must satisfy `isVALID()`. That conveniently means
+// that `Rule::mkINVALID()` can be used to indicate "not found` in `get()`.
+
+class CallFrameInfo::RuleMapLowLevel {
+ using Entry = pair<int, Rule>;
+
+ // The inline capacity of 12 is carefully chosen. It would be wise to make
+ // careful measurements of time, instruction count, allocation count and
+ // allocated bytes before changing it. For x86_64-linux, a value of 8 is
+ // marginally better; using 12 increases the total heap bytes allocated by
+ // around 20%. For arm64-linux, a value of 24 is better; using 12 increases
+ // the total blocks allocated by around 20%. But it's a not bad tradeoff
+ // for both targets, and in any case is vastly superior to the previous
+ // scheme of using `std::map`.
+ mozilla::Vector<Entry, 12> entries_;
+
+ public:
+ void clear() { entries_.clear(); }
+
+ RuleMapLowLevel() { clear(); }
+
+ RuleMapLowLevel& operator=(const RuleMapLowLevel& rhs) {
+ entries_.clear();
+ for (size_t i = 0; i < rhs.entries_.length(); i++) {
+ bool ok = entries_.append(rhs.entries_[i]);
+ MOZ_RELEASE_ASSERT(ok);
+ }
+ return *this;
+ }
+
+ void set(int reg, Rule rule) {
+ MOZ_ASSERT(rule.isVALID());
+ // Find the place where it should go, if any
+ size_t i = 0;
+ size_t nEnt = entries_.length();
+ while (i < nEnt && entries_[i].first < reg) {
+ i++;
+ }
+ if (i == nEnt) {
+ // No entry exists, and all the existing ones are for lower register
+ // numbers. So just add it at the end.
+ bool ok = entries_.append(Entry(reg, rule));
+ MOZ_RELEASE_ASSERT(ok);
+ } else {
+ // It needs to live at location `i`, and ..
+ MOZ_ASSERT(i < nEnt);
+ if (entries_[i].first == reg) {
+ // .. there's already an old entry, so just update it.
+ entries_[i].second = rule;
+ } else {
+ // .. there's no previous entry, so shift `i` and all those following
+ // it one place to the right, and put the new entry at `i`. Doing it
+ // manually is measurably cheaper than using `Vector::insert`.
+ MOZ_ASSERT(entries_[i].first > reg);
+ bool ok = entries_.append(Entry(999999, Rule::mkINVALID()));
+ MOZ_RELEASE_ASSERT(ok);
+ for (size_t j = nEnt; j >= i + 1; j--) {
+ entries_[j] = entries_[j - 1];
+ }
+ entries_[i] = Entry(reg, rule);
+ }
+ }
+ // Check in-order-ness and validity.
+ for (size_t i = 0; i < entries_.length(); i++) {
+ MOZ_ASSERT(entries_[i].second.isVALID());
+ MOZ_ASSERT_IF(i > 0, entries_[i - 1].first < entries_[i].first);
+ }
+ MOZ_ASSERT(get(reg).isVALID());
+ }
+
+ // Find the entry for `reg`, or return `Rule::mkINVALID()` if not found.
+ Rule get(int reg) const {
+ size_t nEnt = entries_.length();
+ // "early exit" in the case where `entries_[i].first > reg` was tested on
+ // x86_64 and found to be slightly slower than just testing all entries,
+ // presumably because the reduced amount of searching was not offset by
+ // the cost of an extra test per iteration.
+ for (size_t i = 0; i < nEnt; i++) {
+ if (entries_[i].first == reg) {
+ CallFrameInfo::Rule ret = entries_[i].second;
+ MOZ_ASSERT(ret.isVALID());
+ return ret;
+ }
+ }
+ return CallFrameInfo::Rule::mkINVALID();
+ }
+
+ // A very simple in-order iteration facility.
+ class Iter {
+ const RuleMapLowLevel* rmll_;
+ size_t nextIx_;
+
+ public:
+ explicit Iter(const RuleMapLowLevel* rmll) : rmll_(rmll), nextIx_(0) {}
+ bool avail() const { return nextIx_ < rmll_->entries_.length(); }
+ bool finished() const { return !avail(); }
+ // Move the iterator to the next entry.
+ void step() {
+ MOZ_RELEASE_ASSERT(nextIx_ < rmll_->entries_.length());
+ nextIx_++;
+ }
+ // Get the value at the current iteration point, but don't advance to the
+ // next entry.
+ pair<int, Rule> peek() {
+ MOZ_RELEASE_ASSERT(nextIx_ < rmll_->entries_.length());
+ return rmll_->entries_[nextIx_];
+ }
+ };
+};
+
+// A map from register numbers to rules. This is a wrapper around
+// `RuleMapLowLevel`, with added logic for dealing with the "special" CFA
+// rule, and with `HandleTransitionTo`, which effectively computes the
+// difference between two `RuleMaps`.
+
+class CallFrameInfo::RuleMap {
+ public:
+ RuleMap() : cfa_rule_(Rule::mkINVALID()) {}
+ RuleMap(const RuleMap& rhs) : cfa_rule_(Rule::mkINVALID()) { *this = rhs; }
+ ~RuleMap() { Clear(); }
+
+ RuleMap& operator=(const RuleMap& rhs);
+
+ // Set the rule for computing the CFA to RULE.
+ void SetCFARule(Rule rule) { cfa_rule_ = rule; }
+
+ // Return the current CFA rule. Be careful not to modify it -- it's returned
+ // by value. If you want to modify the CFA rule, use CFARuleRef() instead.
+ // We use these two 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_; }
+ Rule* CFARuleRef() { return &cfa_rule_; }
+
+ // Return the rule for REG, or the INVALID rule if there is none.
+ Rule RegisterRule(int reg) const;
+
+ // Set the rule for computing REG to 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:
+ // Remove all register rules and clear cfa_rule_.
+ void Clear();
+
+ // The rule for computing the canonical frame address.
+ Rule cfa_rule_;
+
+ // A map from register numbers to postfix expressions to recover
+ // their values.
+ RuleMapLowLevel registers_;
+};
+
+CallFrameInfo::RuleMap& CallFrameInfo::RuleMap::operator=(const RuleMap& rhs) {
+ Clear();
+ if (rhs.cfa_rule_.isVALID()) cfa_rule_ = rhs.cfa_rule_;
+ registers_ = rhs.registers_;
+ return *this;
+}
+
+CallFrameInfo::Rule CallFrameInfo::RuleMap::RegisterRule(int reg) const {
+ MOZ_ASSERT(reg != Handler::kCFARegister);
+ return registers_.get(reg);
+}
+
+void CallFrameInfo::RuleMap::SetRegisterRule(int reg, Rule rule) {
+ MOZ_ASSERT(reg != Handler::kCFARegister);
+ MOZ_ASSERT(rule.isVALID());
+ registers_.set(reg, 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_.isVALID() && new_rules.cfa_rule_.isVALID()) {
+ if (cfa_rule_ != new_rules.cfa_rule_ &&
+ !new_rules.cfa_rule_.Handle(handler, address, Handler::kCFARegister)) {
+ return false;
+ }
+ } else if (cfa_rule_.isVALID()) {
+ // 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_.isVALID()) {
+ // 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.
+ RuleMapLowLevel::Iter old_it(&registers_);
+ RuleMapLowLevel::Iter new_it(&new_rules.registers_);
+ while (!old_it.finished() && !new_it.finished()) {
+ pair<int, Rule> old_pair = old_it.peek();
+ pair<int, Rule> new_pair = new_it.peek();
+ if (old_pair.first < new_pair.first) {
+ // This RuleMap has an entry for old.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_pair.first)) {
+ return false;
+ }
+ old_it.step();
+ } else if (old_pair.first > new_pair.first) {
+ // NEW_RULES has an entry for new_pair.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_pair.second != new_pair.second &&
+ !new_pair.second.Handle(handler, address, new_pair.first)) {
+ return false;
+ }
+ new_it.step();
+ old_it.step();
+ }
+ }
+ // Finish off entries from this RuleMap with no counterparts in new_rules.
+ while (!old_it.finished()) {
+ pair<int, Rule> old_pair = old_it.peek();
+ if (!handler->SameValueRule(address, old_pair.first)) return false;
+ old_it.step();
+ }
+ // 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.finished());
+
+ return true;
+}
+
+// Remove all register rules and clear cfa_rule_.
+void CallFrameInfo::RuleMap::Clear() {
+ cfa_rule_ = Rule::mkINVALID();
+ 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.
+ ImageSlice 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.
+ MOZ_ALWAYS_INLINE bool DoInstruction();
+
+ // Repeatedly call `DoInstruction`, until either:
+ // * it returns `false`, which indicates some kind of failure,
+ // in which case return `false` from here too, or
+ // * we've run out of instructions (that is, `cursor_ >= entry_->end`),
+ // in which case return `true`.
+ // This is marked as never-inline because it is the only place that
+ // `DoInstruction` is called from, and we want to maximise the chances that
+ // `DoInstruction` is inlined into this routine.
+ MOZ_NEVER_INLINE bool DoInstructions();
+
+ // 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;
+ if (!DoInstructions()) {
+ 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;
+ return DoInstructions();
+}
+
+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 = ImageSlice(cursor_, expression_length);
+ cursor_ += expression_length;
+ break;
+ }
+
+ default:
+ MOZ_ASSERT(0);
+ }
+ }
+
+ return true;
+}
+
+MOZ_ALWAYS_INLINE
+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_.CFARuleRef();
+ if (!cfa_rule->isVALID()) {
+ 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 = Rule::mkValExpressionRule(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, Rule::mkUndefinedRule()))
+ 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, Rule::mkSameValueRule()))
+ 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, Rule::mkRegisterRule(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, Rule::mkExpressionRule(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,
+ Rule::mkValExpressionRule(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().isVALID() && !new_rules.CFARule().isVALID()) {
+ 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, Rule::mkRegisterRule(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, Rule::mkOffsetRule(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;
+}
+
+// See declaration above for rationale re the no-inline directive.
+MOZ_NEVER_INLINE
+bool CallFrameInfo::State::DoInstructions() {
+ while (cursor_ < entry_->end) {
+ if (!DoInstruction()) {
+ return false;
+ }
+ }
+ return true;
+}
+
+bool CallFrameInfo::State::DoDefCFA(unsigned base_register, long offset) {
+ Rule rule = Rule::mkValOffsetRule(base_register, offset);
+ rules_.SetCFARule(rule);
+ return rule.Handle(handler_, address_, Handler::kCFARegister);
+}
+
+bool CallFrameInfo::State::DoDefCFAOffset(long offset) {
+ Rule* cfa_rule = rules_.CFARuleRef();
+ if (!cfa_rule->isVALID()) {
+ 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().isVALID()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ Rule rule = Rule::mkOffsetRule(Handler::kCFARegister, offset);
+ return DoRule(reg, rule);
+}
+
+bool CallFrameInfo::State::DoValOffset(unsigned reg, long offset) {
+ if (!rules_.CFARule().isVALID()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ return DoRule(reg, Rule::mkValOffsetRule(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.isVALID()) {
+ // 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 = Rule::mkSameValueRule();
+ }
+ 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 4 (there was never a
+ // version 2 of CFI data). For .eh_frame, we handle versions 1 and 4 as well;
+ // the difference between those versions seems to be the same as for
+ // .debug_frame.
+ if (cie->version < 1 || cie->version > 4) {
+ 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;
+ }
+ }
+
+ if (cie->version >= 4) {
+ // Check that the address_size and segment_size fields are plausible.
+ if (cie->end - cursor < 2) {
+ return ReportIncomplete(cie);
+ }
+ uint8_t address_size = reader_->ReadOneByte(cursor);
+ cursor++;
+ if (address_size != sizeof(void*)) {
+ // This is not per-se invalid CFI. But we can reasonably expect to
+ // be running on a target of the same word size as the CFI is for,
+ // so we reject this case.
+ reporter_->InvalidDwarf4Artefact(cie->offset, "Invalid address_size");
+ return false;
+ }
+ uint8_t segment_size = reader_->ReadOneByte(cursor);
+ cursor++;
+ if (segment_size != 0) {
+ // This is also not per-se invalid CFI, but we don't currently handle
+ // the case of non-zero |segment_size|.
+ reporter_->InvalidDwarf4Artefact(cie->offset, "Invalid segment_size");
+ return false;
+ }
+ // We only continue parsing if |segment_size| is zero. If this routine
+ // is ever changed to allow non-zero |segment_size|, then
+ // ReadFDEFields() below will have to be changed to match, per comments
+ // there.
+ }
+
+ // 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;
+
+ // At this point, for Dwarf 4 and above, we are assuming that the
+ // associated CIE has its |segment_size| field equal to zero. This is
+ // checked for in ReadCIEFields() above. If ReadCIEFields() is ever
+ // changed to allow non-zero |segment_size| CIEs then we will have to read
+ // the segment_selector value at this point.
+
+ 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::InvalidDwarf4Artefact(uint64 offset,
+ const char* what) {
+ char* what_safe = strndup(what, 100);
+ char buf[300];
+ SprintfLiteral(buf,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies invalid Dwarf4 artefact: %s\n",
+ filename_.c_str(), offset, section_.c_str(), what_safe);
+ log_(buf);
+ free(what_safe);
+}
+
+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", "$fsw"
+ */
+ return 8 + 8 + 1 + 8 + 8 + 8 + 8 + 1 + 8 + 4 + 2 + 3;
+}
+
+// Per ARM IHI 0040A, section 3.1
+unsigned int DwarfCFIToModule::RegisterNames::ARM() {
+ /*
+ 8 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
+ 8 "r8", "r9", "r10", "r11", "r12", "sp", "lr", "pc",
+ 8 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
+ 8 "fps", "cpsr", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
+ 8 "s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15",
+ 8 "s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23",
+ 8 "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31",
+ 8 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7"
+ */
+ return 13 * 8;
+}
+
+// Per ARM IHI 0057A, section 3.1
+unsigned int DwarfCFIToModule::RegisterNames::ARM64() {
+ /*
+ 8 "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
+ 8 "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
+ 8 "x16" "x17", "x18", "x19", "x20", "x21", "x22", "x23",
+ 8 "x24", "x25", "x26", "x27", "x28", "x29", "x30","sp",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "", "", "", "", "", "", "", "",
+ 8 "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7",
+ 8 "v8", "v9", "v10", "v11", "v12", "v13", "v14", "v15",
+ 8 "v16", "v17", "v18", "v19", "v20", "v21", "v22, "v23",
+ 8 "v24", "x25", "x26, "x27", "v28", "v29", "v30", "v31",
+ */
+ return 12 * 8;
+}
+
+unsigned int DwarfCFIToModule::RegisterNames::MIPS() {
+ /*
+ 8 "$zero", "$at", "$v0", "$v1", "$a0", "$a1", "$a2", "$a3",
+ 8 "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7",
+ 8 "$s0", "$s1", "$s2", "$s3", "$s4", "$s5", "$s6", "$s7",
+ 8 "$t8", "$t9", "$k0", "$k1", "$gp", "$sp", "$fp", "$ra",
+ 9 "$lo", "$hi", "$pc", "$f0", "$f1", "$f2", "$f3", "$f4", "$f5",
+ 8 "$f6", "$f7", "$f8", "$f9", "$f10", "$f11", "$f12", "$f13",
+ 7 "$f14", "$f15", "$f16", "$f17", "$f18", "$f19", "$f20",
+ 7 "$f21", "$f22", "$f23", "$f24", "$f25", "$f26", "$f27",
+ 6 "$f28", "$f29", "$f30", "$f31", "$fcsr", "$fir"
+ */
+ return 8 + 8 + 8 + 8 + 9 + 8 + 7 + 7 + 6;
+}
+
+// See prototype for comments.
+int32_t parseDwarfExpr(Summariser* summ, const ByteReader* reader,
+ ImageSlice expr, bool debug, bool pushCfaAtStart,
+ bool derefAtEnd) {
+ const char* cursor = expr.start_;
+ 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 ImageSlice& 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 ImageSlice& 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-13 13:13:29 +0000