Index: experimental/visual_studio_plugin/third_party/breakpad/common/dwarf/dwarf2reader.h |
diff --git a/experimental/visual_studio_plugin/third_party/breakpad/common/dwarf/dwarf2reader.h b/experimental/visual_studio_plugin/third_party/breakpad/common/dwarf/dwarf2reader.h |
deleted file mode 100644 |
index 3b6bf4db8cfd843ac13cb909629c962de4aa0967..0000000000000000000000000000000000000000 |
--- a/experimental/visual_studio_plugin/third_party/breakpad/common/dwarf/dwarf2reader.h |
+++ /dev/null |
@@ -1,1048 +0,0 @@ |
-// -*- mode: C++ -*- |
- |
-// Copyright (c) 2010 Google Inc. All Rights Reserved. |
-// |
-// Redistribution and use in source and binary forms, with or without |
-// modification, are permitted provided that the following conditions are |
-// met: |
-// |
-// * Redistributions of source code must retain the above copyright |
-// notice, this list of conditions and the following disclaimer. |
-// * Redistributions in binary form must reproduce the above |
-// copyright notice, this list of conditions and the following disclaimer |
-// in the documentation and/or other materials provided with the |
-// distribution. |
-// * Neither the name of Google Inc. nor the names of its |
-// contributors may be used to endorse or promote products derived from |
-// this software without specific prior written permission. |
-// |
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
- |
-// CFI reader author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> |
- |
-// This file contains definitions related to the DWARF2/3 reader and |
-// it's handler interfaces. |
-// The DWARF2/3 specification can be found at |
-// http://dwarf.freestandards.org and should be considered required |
-// reading if you wish to modify the implementation. |
-// Only a cursory attempt is made to explain terminology that is |
-// used here, as it is much better explained in the standard documents |
-#ifndef COMMON_DWARF_DWARF2READER_H__ |
-#define COMMON_DWARF_DWARF2READER_H__ |
- |
-#include <list> |
-#include <map> |
-#include <string> |
-#include <utility> |
-#include <vector> |
- |
-#ifdef WIN32 |
-#undef min |
-#undef max |
-#pragma warning(disable:4800 4244) |
-#endif |
- |
-#include "common/dwarf/bytereader.h" |
-#include "common/dwarf/dwarf2enums.h" |
-#include "common/dwarf/types.h" |
- |
-using namespace std; |
- |
-namespace dwarf2reader { |
-struct LineStateMachine; |
-class Dwarf2Handler; |
-class LineInfoHandler; |
- |
-// This maps from a string naming a section to a pair containing a |
-// the data for the section, and the size of the section. |
-typedef map<string, pair<const char*, uint64> > SectionMap; |
-typedef list<pair<enum DwarfAttribute, enum DwarfForm> > AttributeList; |
-typedef AttributeList::iterator AttributeIterator; |
-typedef AttributeList::const_iterator ConstAttributeIterator; |
- |
-struct LineInfoHeader { |
- uint64 total_length; |
- uint16 version; |
- uint64 prologue_length; |
- uint8 min_insn_length; // insn stands for instructin |
- bool default_is_stmt; // stmt stands for statement |
- int8 line_base; |
- uint8 line_range; |
- uint8 opcode_base; |
- // Use a pointer so that signalsafe_addr2line is able to use this structure |
- // without heap allocation problem. |
- vector<unsigned char> *std_opcode_lengths; |
-}; |
- |
-class LineInfo { |
- public: |
- |
- // Initializes a .debug_line reader. Buffer and buffer length point |
- // to the beginning and length of the line information to read. |
- // Reader is a ByteReader class that has the endianness set |
- // properly. |
- LineInfo(const char* buffer_, uint64 buffer_length, |
- ByteReader* reader, LineInfoHandler* handler); |
- |
- virtual ~LineInfo() { |
- if (header_.std_opcode_lengths) { |
- delete header_.std_opcode_lengths; |
- } |
- } |
- |
- // Start processing line info, and calling callbacks in the handler. |
- // Consumes the line number information for a single compilation unit. |
- // Returns the number of bytes processed. |
- uint64 Start(); |
- |
- // Process a single line info opcode at START using the state |
- // machine at LSM. Return true if we should define a line using the |
- // current state of the line state machine. Place the length of the |
- // opcode in LEN. |
- // If LSM_PASSES_PC is non-NULL, this function also checks if the lsm |
- // passes the address of PC. In other words, LSM_PASSES_PC will be |
- // set to true, if the following condition is met. |
- // |
- // lsm's old address < PC <= lsm's new address |
- static bool ProcessOneOpcode(ByteReader* reader, |
- LineInfoHandler* handler, |
- const struct LineInfoHeader &header, |
- const char* start, |
- struct LineStateMachine* lsm, |
- size_t* len, |
- uintptr pc, |
- bool *lsm_passes_pc); |
- |
- private: |
- // Reads the DWARF2/3 header for this line info. |
- void ReadHeader(); |
- |
- // Reads the DWARF2/3 line information |
- void ReadLines(); |
- |
- // The associated handler to call processing functions in |
- LineInfoHandler* handler_; |
- |
- // The associated ByteReader that handles endianness issues for us |
- ByteReader* reader_; |
- |
- // A DWARF2/3 line info header. This is not the same size as |
- // in the actual file, as the one in the file may have a 32 bit or |
- // 64 bit lengths |
- |
- struct LineInfoHeader header_; |
- |
- // buffer is the buffer for our line info, starting at exactly where |
- // the line info to read is. after_header is the place right after |
- // the end of the line information header. |
- const char* buffer_; |
- uint64 buffer_length_; |
- const char* after_header_; |
-}; |
- |
-// This class is the main interface between the line info reader and |
-// the client. The virtual functions inside this get called for |
-// interesting events that happen during line info reading. The |
-// default implementation does nothing |
- |
-class LineInfoHandler { |
- public: |
- LineInfoHandler() { } |
- |
- virtual ~LineInfoHandler() { } |
- |
- // Called when we define a directory. NAME is the directory name, |
- // DIR_NUM is the directory number |
- virtual void DefineDir(const string& name, uint32 dir_num) { } |
- |
- // Called when we define a filename. NAME is the filename, FILE_NUM |
- // is the file number which is -1 if the file index is the next |
- // index after the last numbered index (this happens when files are |
- // dynamically defined by the line program), DIR_NUM is the |
- // directory index for the directory name of this file, MOD_TIME is |
- // the modification time of the file, and LENGTH is the length of |
- // the file |
- virtual void DefineFile(const string& name, int32 file_num, |
- uint32 dir_num, uint64 mod_time, |
- uint64 length) { } |
- |
- // Called when the line info reader has a new line, address pair |
- // ready for us. ADDRESS is the address of the code, LENGTH is the |
- // length of its machine code in bytes, FILE_NUM is the file number |
- // containing the code, LINE_NUM is the line number in that file for |
- // the code, and COLUMN_NUM is the column number the code starts at, |
- // if we know it (0 otherwise). |
- virtual void AddLine(uint64 address, uint64 length, |
- uint32 file_num, uint32 line_num, uint32 column_num) { } |
-}; |
- |
-// The base of DWARF2/3 debug info is a DIE (Debugging Information |
-// Entry. |
-// DWARF groups DIE's into a tree and calls the root of this tree a |
-// "compilation unit". Most of the time, there is one compilation |
-// unit in the .debug_info section for each file that had debug info |
-// generated. |
-// Each DIE consists of |
- |
-// 1. a tag specifying a thing that is being described (ie |
-// DW_TAG_subprogram for functions, DW_TAG_variable for variables, etc |
-// 2. attributes (such as DW_AT_location for location in memory, |
-// DW_AT_name for name), and data for each attribute. |
-// 3. A flag saying whether the DIE has children or not |
- |
-// In order to gain some amount of compression, the format of |
-// each DIE (tag name, attributes and data forms for the attributes) |
-// are stored in a separate table called the "abbreviation table". |
-// This is done because a large number of DIEs have the exact same tag |
-// and list of attributes, but different data for those attributes. |
-// As a result, the .debug_info section is just a stream of data, and |
-// requires reading of the .debug_abbrev section to say what the data |
-// means. |
- |
-// As a warning to the user, it should be noted that the reason for |
-// using absolute offsets from the beginning of .debug_info is that |
-// DWARF2/3 supports referencing DIE's from other DIE's by their offset |
-// from either the current compilation unit start, *or* the beginning |
-// of the .debug_info section. This means it is possible to reference |
-// a DIE in one compilation unit from a DIE in another compilation |
-// unit. This style of reference is usually used to eliminate |
-// duplicated information that occurs across compilation |
-// units, such as base types, etc. GCC 3.4+ support this with |
-// -feliminate-dwarf2-dups. Other toolchains will sometimes do |
-// duplicate elimination in the linker. |
- |
-class CompilationUnit { |
- public: |
- |
- // Initialize a compilation unit. This requires a map of sections, |
- // the offset of this compilation unit in the .debug_info section, a |
- // ByteReader, and a Dwarf2Handler class to call callbacks in. |
- CompilationUnit(const SectionMap& sections, uint64 offset, |
- ByteReader* reader, Dwarf2Handler* handler); |
- virtual ~CompilationUnit() { |
- if (abbrevs_) delete abbrevs_; |
- } |
- |
- // Begin reading a Dwarf2 compilation unit, and calling the |
- // callbacks in the Dwarf2Handler |
- |
- // Return the full length of the compilation unit, including |
- // headers. This plus the starting offset passed to the constructor |
- // is the offset of the end of the compilation unit --- and the |
- // start of the next compilation unit, if there is one. |
- uint64 Start(); |
- |
- private: |
- |
- // This struct represents a single DWARF2/3 abbreviation |
- // The abbreviation tells how to read a DWARF2/3 DIE, and consist of a |
- // tag and a list of attributes, as well as the data form of each attribute. |
- struct Abbrev { |
- uint32 number; |
- enum DwarfTag tag; |
- bool has_children; |
- AttributeList attributes; |
- }; |
- |
- // A DWARF2/3 compilation unit header. This is not the same size as |
- // in the actual file, as the one in the file may have a 32 bit or |
- // 64 bit length. |
- struct CompilationUnitHeader { |
- uint64 length; |
- uint16 version; |
- uint64 abbrev_offset; |
- uint8 address_size; |
- } header_; |
- |
- // Reads the DWARF2/3 header for this compilation unit. |
- void ReadHeader(); |
- |
- // Reads the DWARF2/3 abbreviations for this compilation unit |
- void ReadAbbrevs(); |
- |
- // Processes a single DIE for this compilation unit and return a new |
- // pointer just past the end of it |
- const char* ProcessDIE(uint64 dieoffset, |
- const char* start, |
- const Abbrev& abbrev); |
- |
- // Processes a single attribute and return a new pointer just past the |
- // end of it |
- const char* ProcessAttribute(uint64 dieoffset, |
- const char* start, |
- enum DwarfAttribute attr, |
- enum DwarfForm form); |
- |
- // Processes all DIEs for this compilation unit |
- void ProcessDIEs(); |
- |
- // Skips the die with attributes specified in ABBREV starting at |
- // START, and return the new place to position the stream to. |
- const char* SkipDIE(const char* start, |
- const Abbrev& abbrev); |
- |
- // Skips the attribute starting at START, with FORM, and return the |
- // new place to position the stream to. |
- const char* SkipAttribute(const char* start, |
- enum DwarfForm form); |
- |
- // Offset from section start is the offset of this compilation unit |
- // from the beginning of the .debug_info section. |
- uint64 offset_from_section_start_; |
- |
- // buffer is the buffer for our CU, starting at .debug_info + offset |
- // passed in from constructor. |
- // after_header points to right after the compilation unit header. |
- const char* buffer_; |
- uint64 buffer_length_; |
- const char* after_header_; |
- |
- // The associated ByteReader that handles endianness issues for us |
- ByteReader* reader_; |
- |
- // The map of sections in our file to buffers containing their data |
- const SectionMap& sections_; |
- |
- // The associated handler to call processing functions in |
- Dwarf2Handler* handler_; |
- |
- // Set of DWARF2/3 abbreviations for this compilation unit. Indexed |
- // by abbreviation number, which means that abbrevs_[0] is not |
- // valid. |
- vector<Abbrev>* abbrevs_; |
- |
- // String section buffer and length, if we have a string section. |
- // This is here to avoid doing a section lookup for strings in |
- // ProcessAttribute, which is in the hot path for DWARF2 reading. |
- const char* string_buffer_; |
- uint64 string_buffer_length_; |
-}; |
- |
-// This class is the main interface between the reader and the |
-// client. The virtual functions inside this get called for |
-// interesting events that happen during DWARF2 reading. |
-// The default implementation skips everything. |
- |
-class Dwarf2Handler { |
- public: |
- Dwarf2Handler() { } |
- |
- virtual ~Dwarf2Handler() { } |
- |
- // Start to process a compilation unit at OFFSET from the beginning of the |
- // .debug_info section. Return false if you would like to skip this |
- // compilation unit. |
- virtual bool StartCompilationUnit(uint64 offset, uint8 address_size, |
- uint8 offset_size, uint64 cu_length, |
- uint8 dwarf_version) { return false; } |
- |
- // Start to process a DIE at OFFSET from the beginning of the .debug_info |
- // section. Return false if you would like to skip this DIE. |
- virtual bool StartDIE(uint64 offset, enum DwarfTag tag, |
- const AttributeList& attrs) { return false; } |
- |
- // Called when we have an attribute with unsigned data to give to our |
- // handler. The attribute is for the DIE at OFFSET from the beginning of the |
- // .debug_info section. Its name is ATTR, its form is FORM, and its value is |
- // DATA. |
- virtual void ProcessAttributeUnsigned(uint64 offset, |
- enum DwarfAttribute attr, |
- enum DwarfForm form, |
- uint64 data) { } |
- |
- // Called when we have an attribute with signed data to give to our handler. |
- // The attribute is for the DIE at OFFSET from the beginning of the |
- // .debug_info section. Its name is ATTR, its form is FORM, and its value is |
- // DATA. |
- virtual void ProcessAttributeSigned(uint64 offset, |
- enum DwarfAttribute attr, |
- enum DwarfForm form, |
- int64 data) { } |
- |
- // Called when we have an attribute whose value is a reference to |
- // another DIE. The attribute belongs to the DIE at OFFSET from the |
- // beginning of the .debug_info section. Its name is ATTR, its form |
- // is FORM, and the offset of the DIE being referred to from the |
- // beginning of the .debug_info section is DATA. |
- virtual void ProcessAttributeReference(uint64 offset, |
- enum DwarfAttribute attr, |
- enum DwarfForm form, |
- uint64 data) { } |
- |
- // Called when we have an attribute with a buffer of data to give to our |
- // handler. The attribute is for the DIE at OFFSET from the beginning of the |
- // .debug_info section. Its name is ATTR, its form is FORM, DATA points to |
- // the buffer's contents, and its length in bytes is LENGTH. The buffer is |
- // owned by the caller, not the callee, and may not persist for very long. |
- // If you want the data to be available later, it needs to be copied. |
- virtual void ProcessAttributeBuffer(uint64 offset, |
- enum DwarfAttribute attr, |
- enum DwarfForm form, |
- const char* data, |
- uint64 len) { } |
- |
- // Called when we have an attribute with string data to give to our handler. |
- // The attribute is for the DIE at OFFSET from the beginning of the |
- // .debug_info section. Its name is ATTR, its form is FORM, and its value is |
- // DATA. |
- virtual void ProcessAttributeString(uint64 offset, |
- enum DwarfAttribute attr, |
- enum DwarfForm form, |
- const string& data) { } |
- |
- // Called when finished processing the DIE at OFFSET. |
- // Because DWARF2/3 specifies a tree of DIEs, you may get starts |
- // before ends of the previous DIE, as we process children before |
- // ending the parent. |
- virtual void EndDIE(uint64 offset) { } |
- |
-}; |
- |
-// This class is a reader for DWARF's Call Frame Information. CFI |
-// describes how to unwind stack frames --- even for functions that do |
-// not follow fixed conventions for saving registers, whose frame size |
-// varies as they execute, etc. |
-// |
-// CFI describes, at each machine instruction, how to compute the |
-// stack frame's base address, how to find the return address, and |
-// where to find the saved values of the caller's registers (if the |
-// callee has stashed them somewhere to free up the registers for its |
-// own use). |
-// |
-// For example, suppose we have a function whose machine code looks |
-// like this (imagine an assembly language that looks like C, for a |
-// machine with 32-bit registers, and a stack that grows towards lower |
-// addresses): |
-// |
-// func: ; entry point; return address at sp |
-// func+0: sp = sp - 16 ; allocate space for stack frame |
-// func+1: sp[12] = r0 ; save r0 at sp+12 |
-// ... ; other code, not frame-related |
-// func+10: sp -= 4; *sp = x ; push some x on the stack |
-// ... ; other code, not frame-related |
-// func+20: r0 = sp[16] ; restore saved r0 |
-// func+21: sp += 20 ; pop whole stack frame |
-// func+22: pc = *sp; sp += 4 ; pop return address and jump to it |
-// |
-// DWARF CFI is (a very compressed representation of) a table with a |
-// row for each machine instruction address and a column for each |
-// register showing how to restore it, if possible. |
-// |
-// A special column named "CFA", for "Canonical Frame Address", tells how |
-// to compute the base address of the frame; registers' entries may |
-// refer to the CFA in describing where the registers are saved. |
-// |
-// Another special column, named "RA", represents the return address. |
-// |
-// For example, here is a complete (uncompressed) table describing the |
-// function above: |
-// |
-// insn cfa r0 r1 ... ra |
-// ======================================= |
-// func+0: sp cfa[0] |
-// func+1: sp+16 cfa[0] |
-// func+2: sp+16 cfa[-4] cfa[0] |
-// func+11: sp+20 cfa[-4] cfa[0] |
-// func+21: sp+20 cfa[0] |
-// func+22: sp cfa[0] |
-// |
-// Some things to note here: |
-// |
-// - Each row describes the state of affairs *before* executing the |
-// instruction at the given address. Thus, the row for func+0 |
-// describes the state before we allocate the stack frame. In the |
-// next row, the formula for computing the CFA has changed, |
-// reflecting that allocation. |
-// |
-// - The other entries are written in terms of the CFA; this allows |
-// them to remain unchanged as the stack pointer gets bumped around. |
-// For example, the rule for recovering the return address (the "ra" |
-// column) remains unchanged throughout the function, even as the |
-// stack pointer takes on three different offsets from the return |
-// address. |
-// |
-// - Although we haven't shown it, most calling conventions designate |
-// "callee-saves" and "caller-saves" registers. The callee must |
-// preserve the values of callee-saves registers; if it uses them, |
-// it must save their original values somewhere, and restore them |
-// before it returns. In contrast, the callee is free to trash |
-// caller-saves registers; if the callee uses these, it will |
-// probably not bother to save them anywhere, and the CFI will |
-// probably mark their values as "unrecoverable". |
-// |
-// (However, since the caller cannot assume the callee was going to |
-// save them, caller-saves registers are probably dead in the caller |
-// anyway, so compilers usually don't generate CFA for caller-saves |
-// registers.) |
-// |
-// - Exactly where the CFA points is a matter of convention that |
-// depends on the architecture and ABI in use. In the example, the |
-// CFA is the value the stack pointer had upon entry to the |
-// function, pointing at the saved return address. But on the x86, |
-// the call frame information generated by GCC follows the |
-// convention that the CFA is the address *after* the saved return |
-// address. |
-// |
-// But by definition, the CFA remains constant throughout the |
-// lifetime of the frame. This makes it a useful value for other |
-// columns to refer to. It is also gives debuggers a useful handle |
-// for identifying a frame. |
-// |
-// If you look at the table above, you'll notice that a given entry is |
-// often the same as the one immediately above it: most instructions |
-// change only one or two aspects of the stack frame, if they affect |
-// it at all. The DWARF format takes advantage of this fact, and |
-// reduces the size of the data by mentioning only the addresses and |
-// columns at which changes take place. So for the above, DWARF CFI |
-// data would only actually mention the following: |
-// |
-// insn cfa r0 r1 ... ra |
-// ======================================= |
-// func+0: sp cfa[0] |
-// func+1: sp+16 |
-// func+2: cfa[-4] |
-// func+11: sp+20 |
-// func+21: r0 |
-// func+22: sp |
-// |
-// In fact, this is the way the parser reports CFI to the consumer: as |
-// a series of statements of the form, "At address X, column Y changed |
-// to Z," and related conventions for describing the initial state. |
-// |
-// Naturally, it would be impractical to have to scan the entire |
-// program's CFI, noting changes as we go, just to recover the |
-// unwinding rules in effect at one particular instruction. To avoid |
-// this, CFI data is grouped into "entries", each of which covers a |
-// specified range of addresses and begins with a complete statement |
-// of the rules for all recoverable registers at that starting |
-// address. Each entry typically covers a single function. |
-// |
-// Thus, to compute the contents of a given row of the table --- that |
-// is, rules for recovering the CFA, RA, and registers at a given |
-// instruction --- the consumer should find the entry that covers that |
-// instruction's address, start with the initial state supplied at the |
-// beginning of the entry, and work forward until it has processed all |
-// the changes up to and including those for the present instruction. |
-// |
-// There are seven kinds of rules that can appear in an entry of the |
-// table: |
-// |
-// - "undefined": The given register is not preserved by the callee; |
-// its value cannot be recovered. |
-// |
-// - "same value": This register has the same value it did in the callee. |
-// |
-// - offset(N): The register is saved at offset N from the CFA. |
-// |
-// - val_offset(N): The value the register had in the caller is the |
-// CFA plus offset N. (This is usually only useful for describing |
-// the stack pointer.) |
-// |
-// - register(R): The register's value was saved in another register R. |
-// |
-// - expression(E): Evaluating the DWARF expression E using the |
-// current frame's registers' values yields the address at which the |
-// register was saved. |
-// |
-// - val_expression(E): Evaluating the DWARF expression E using the |
-// current frame's registers' values yields the value the register |
-// had in the caller. |
- |
-class CallFrameInfo { |
- public: |
- // The different kinds of entries one finds in CFI. Used internally, |
- // and for error reporting. |
- enum EntryKind { kUnknown, kCIE, kFDE, kTerminator }; |
- |
- // The handler class to which the parser hands the parsed call frame |
- // information. Defined below. |
- class Handler; |
- |
- // A reporter class, which CallFrameInfo uses to report errors |
- // encountered while parsing call frame information. Defined below. |
- class Reporter; |
- |
- // Create a DWARF CFI parser. BUFFER points to the contents of the |
- // .debug_frame section to parse; BUFFER_LENGTH is its length in bytes. |
- // REPORTER is an error reporter the parser should use to report |
- // problems. READER is a ByteReader instance that has the endianness and |
- // address size set properly. Report the data we find to HANDLER. |
- // |
- // This class can also parse Linux C++ exception handling data, as found |
- // in '.eh_frame' sections. This data is a variant of DWARF CFI that is |
- // placed in loadable segments so that it is present in the program's |
- // address space, and is interpreted by the C++ runtime to search the |
- // call stack for a handler interested in the exception being thrown, |
- // actually pop the frames, and find cleanup code to run. |
- // |
- // There are two differences between the call frame information described |
- // in the DWARF standard and the exception handling data Linux places in |
- // the .eh_frame section: |
- // |
- // - Exception handling data uses uses a different format for call frame |
- // information entry headers. The distinguished CIE id, the way FDEs |
- // refer to their CIEs, and the way the end of the series of entries is |
- // determined are all slightly different. |
- // |
- // If the constructor's EH_FRAME argument is true, then the |
- // CallFrameInfo parses the entry headers as Linux C++ exception |
- // handling data. If EH_FRAME is false or omitted, the CallFrameInfo |
- // parses standard DWARF call frame information. |
- // |
- // - Linux C++ exception handling data uses CIE augmentation strings |
- // beginning with 'z' to specify the presence of additional data after |
- // the CIE and FDE headers and special encodings used for addresses in |
- // frame description entries. |
- // |
- // CallFrameInfo can handle 'z' augmentations in either DWARF CFI or |
- // exception handling data if you have supplied READER with the base |
- // addresses needed to interpret the pointer encodings that 'z' |
- // augmentations can specify. See the ByteReader interface for details |
- // about the base addresses. See the CallFrameInfo::Handler interface |
- // for details about the additional information one might find in |
- // 'z'-augmented data. |
- // |
- // Thus: |
- // |
- // - If you are parsing standard DWARF CFI, as found in a .debug_frame |
- // section, you should pass false for the EH_FRAME argument, or omit |
- // it, and you need not worry about providing READER with the |
- // additional base addresses. |
- // |
- // - If you want to parse Linux C++ exception handling data from a |
- // .eh_frame section, you should pass EH_FRAME as true, and call |
- // READER's Set*Base member functions before calling our Start method. |
- // |
- // - If you want to parse DWARF CFI that uses the 'z' augmentations |
- // (although I don't think any toolchain ever emits such data), you |
- // could pass false for EH_FRAME, but call READER's Set*Base members. |
- // |
- // The extensions the Linux C++ ABI makes to DWARF for exception |
- // handling are described here, rather poorly: |
- // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/dwarfext.html |
- // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html |
- // |
- // The mechanics of C++ exception handling, personality routines, |
- // and language-specific data areas are described here, rather nicely: |
- // http://www.codesourcery.com/public/cxx-abi/abi-eh.html |
- CallFrameInfo(const char *buffer, size_t buffer_length, |
- ByteReader *reader, Handler *handler, Reporter *reporter, |
- bool eh_frame = false) |
- : buffer_(buffer), buffer_length_(buffer_length), |
- reader_(reader), handler_(handler), reporter_(reporter), |
- eh_frame_(eh_frame) { } |
- |
- ~CallFrameInfo() { } |
- |
- // Parse the entries in BUFFER, reporting what we find to HANDLER. |
- // Return true if we reach the end of the section successfully, or |
- // false if we encounter an error. |
- bool Start(); |
- |
- // Return the textual name of KIND. For error reporting. |
- static const char *KindName(EntryKind kind); |
- |
- private: |
- |
- struct CIE; |
- |
- // A CFI entry, either an FDE or a CIE. |
- struct Entry { |
- // The starting offset of the entry in the section, for error |
- // reporting. |
- size_t offset; |
- |
- // The start of this entry in the buffer. |
- const char *start; |
- |
- // Which kind of entry this is. |
- // |
- // We want to be able to use this for error reporting even while we're |
- // in the midst of parsing. Error reporting code may assume that kind, |
- // offset, and start fields are valid, although kind may be kUnknown. |
- EntryKind kind; |
- |
- // The end of this entry's common prologue (initial length and id), and |
- // the start of this entry's kind-specific fields. |
- const char *fields; |
- |
- // The start of this entry's instructions. |
- const char *instructions; |
- |
- // The address past the entry's last byte in the buffer. (Note that |
- // since offset points to the entry's initial length field, and the |
- // length field is the number of bytes after that field, this is not |
- // simply buffer_ + offset + length.) |
- const char *end; |
- |
- // For both DWARF CFI and .eh_frame sections, this is the CIE id in a |
- // CIE, and the offset of the associated CIE in an FDE. |
- uint64 id; |
- |
- // The CIE that applies to this entry, if we've parsed it. If this is a |
- // CIE, then this field points to this structure. |
- CIE *cie; |
- }; |
- |
- // A common information entry (CIE). |
- struct CIE: public Entry { |
- uint8 version; // CFI data version number |
- string augmentation; // vendor format extension markers |
- uint64 code_alignment_factor; // scale for code address adjustments |
- int data_alignment_factor; // scale for stack pointer adjustments |
- unsigned return_address_register; // which register holds the return addr |
- |
- // True if this CIE includes Linux C++ ABI 'z' augmentation data. |
- bool has_z_augmentation; |
- |
- // Parsed 'z' augmentation data. These are meaningful only if |
- // has_z_augmentation is true. |
- bool has_z_lsda; // The 'z' augmentation included 'L'. |
- bool has_z_personality; // The 'z' augmentation included 'P'. |
- bool has_z_signal_frame; // The 'z' augmentation included 'S'. |
- |
- // If has_z_lsda is true, this is the encoding to be used for language- |
- // specific data area pointers in FDEs. |
- DwarfPointerEncoding lsda_encoding; |
- |
- // If has_z_personality is true, this is the encoding used for the |
- // personality routine pointer in the augmentation data. |
- DwarfPointerEncoding personality_encoding; |
- |
- // If has_z_personality is true, this is the address of the personality |
- // routine --- or, if personality_encoding & DW_EH_PE_indirect, the |
- // address where the personality routine's address is stored. |
- uint64 personality_address; |
- |
- // This is the encoding used for addresses in the FDE header and |
- // in DW_CFA_set_loc instructions. This is always valid, whether |
- // or not we saw a 'z' augmentation string; its default value is |
- // DW_EH_PE_absptr, which is what normal DWARF CFI uses. |
- DwarfPointerEncoding pointer_encoding; |
- }; |
- |
- // A frame description entry (FDE). |
- struct FDE: public Entry { |
- uint64 address; // start address of described code |
- uint64 size; // size of described code, in bytes |
- |
- // If cie->has_z_lsda is true, then this is the language-specific data |
- // area's address --- or its address's address, if cie->lsda_encoding |
- // has the DW_EH_PE_indirect bit set. |
- uint64 lsda_address; |
- }; |
- |
- // Internal use. |
- class Rule; |
- class UndefinedRule; |
- class SameValueRule; |
- class OffsetRule; |
- class ValOffsetRule; |
- class RegisterRule; |
- class ExpressionRule; |
- class ValExpressionRule; |
- class RuleMap; |
- class State; |
- |
- // Parse the initial length and id of a CFI entry, either a CIE, an FDE, |
- // or a .eh_frame end-of-data mark. CURSOR points to the beginning of the |
- // data to parse. On success, populate ENTRY as appropriate, and return |
- // true. On failure, report the problem, and return false. Even if we |
- // return false, set ENTRY->end to the first byte after the entry if we |
- // were able to figure that out, or NULL if we weren't. |
- bool ReadEntryPrologue(const char *cursor, Entry *entry); |
- |
- // Parse the fields of a CIE after the entry prologue, including any 'z' |
- // augmentation data. Assume that the 'Entry' fields of CIE are |
- // populated; use CIE->fields and CIE->end as the start and limit for |
- // parsing. On success, populate the rest of *CIE, and return true; on |
- // failure, report the problem and return false. |
- bool ReadCIEFields(CIE *cie); |
- |
- // Parse the fields of an FDE after the entry prologue, including any 'z' |
- // augmentation data. Assume that the 'Entry' fields of *FDE are |
- // initialized; use FDE->fields and FDE->end as the start and limit for |
- // parsing. Assume that FDE->cie is fully initialized. On success, |
- // populate the rest of *FDE, and return true; on failure, report the |
- // problem and return false. |
- bool ReadFDEFields(FDE *fde); |
- |
- // Report that ENTRY is incomplete, and return false. This is just a |
- // trivial wrapper for invoking reporter_->Incomplete; it provides a |
- // little brevity. |
- bool ReportIncomplete(Entry *entry); |
- |
- // Return true if ENCODING has the DW_EH_PE_indirect bit set. |
- static bool IsIndirectEncoding(DwarfPointerEncoding encoding) { |
- return encoding & DW_EH_PE_indirect; |
- } |
- |
- // The contents of the DWARF .debug_info section we're parsing. |
- const char *buffer_; |
- size_t buffer_length_; |
- |
- // 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_; |
- |
- // True if we are processing .eh_frame-format data. |
- bool eh_frame_; |
-}; |
- |
-// The handler class for CallFrameInfo. The a CFI parser calls the |
-// member functions of a handler object to report the data it finds. |
-class CallFrameInfo::Handler { |
- public: |
- // The pseudo-register number for the canonical frame address. |
- enum { kCFARegister = -1 }; |
- |
- Handler() { } |
- virtual ~Handler() { } |
- |
- // The parser has found CFI for the machine code at ADDRESS, |
- // extending for LENGTH bytes. OFFSET is the offset of the frame |
- // description entry in the section, for use in error messages. |
- // VERSION is the version number of the CFI format. AUGMENTATION is |
- // a string describing any producer-specific extensions present in |
- // the data. RETURN_ADDRESS is the number of the register that holds |
- // the address to which the function should return. |
- // |
- // Entry should return true to process this CFI, or false to skip to |
- // the next entry. |
- // |
- // The parser invokes Entry for each Frame Description Entry (FDE) |
- // it finds. The parser doesn't report Common Information Entries |
- // to the handler explicitly; instead, if the handler elects to |
- // process a given FDE, the parser reiterates the appropriate CIE's |
- // contents at the beginning of the FDE's rules. |
- virtual bool Entry(size_t offset, uint64 address, uint64 length, |
- uint8 version, const string &augmentation, |
- unsigned return_address) = 0; |
- |
- // When the Entry function returns true, the parser calls these |
- // handler functions repeatedly to describe the rules for recovering |
- // registers at each instruction in the given range of machine code. |
- // Immediately after a call to Entry, the handler should assume that |
- // the rule for each callee-saves register is "unchanged" --- that |
- // is, that the register still has the value it had in the caller. |
- // |
- // If a *Rule function returns true, we continue processing this entry's |
- // instructions. If a *Rule function returns false, we stop evaluating |
- // instructions, and skip to the next entry. Either way, we call End |
- // before going on to the next entry. |
- // |
- // In all of these functions, if the REG parameter is kCFARegister, then |
- // the rule describes how to find the canonical frame address. |
- // kCFARegister may be passed as a BASE_REGISTER argument, meaning that |
- // the canonical frame address should be used as the base address for the |
- // computation. All other REG values will be positive. |
- |
- // At ADDRESS, register REG's value is not recoverable. |
- virtual bool UndefinedRule(uint64 address, int reg) = 0; |
- |
- // At ADDRESS, register REG's value is the same as that it had in |
- // the caller. |
- virtual bool SameValueRule(uint64 address, int reg) = 0; |
- |
- // At ADDRESS, register REG has been saved at offset OFFSET from |
- // BASE_REGISTER. |
- virtual bool OffsetRule(uint64 address, int reg, |
- int base_register, long offset) = 0; |
- |
- // At ADDRESS, the caller's value of register REG is the current |
- // value of BASE_REGISTER plus OFFSET. (This rule doesn't provide an |
- // address at which the register's value is saved.) |
- virtual bool ValOffsetRule(uint64 address, int reg, |
- int base_register, long offset) = 0; |
- |
- // At ADDRESS, register REG has been saved in BASE_REGISTER. This differs |
- // from ValOffsetRule(ADDRESS, REG, BASE_REGISTER, 0), in that |
- // BASE_REGISTER is the "home" for REG's saved value: if you want to |
- // assign to a variable whose home is REG in the calling frame, you |
- // should put the value in BASE_REGISTER. |
- virtual bool RegisterRule(uint64 address, int reg, int base_register) = 0; |
- |
- // At ADDRESS, the DWARF expression EXPRESSION yields the address at |
- // which REG was saved. |
- virtual bool ExpressionRule(uint64 address, int reg, |
- const string &expression) = 0; |
- |
- // At ADDRESS, the DWARF expression EXPRESSION yields the caller's |
- // value for REG. (This rule doesn't provide an address at which the |
- // register's value is saved.) |
- virtual bool ValExpressionRule(uint64 address, int reg, |
- const string &expression) = 0; |
- |
- // Indicate that the rules for the address range reported by the |
- // last call to Entry are complete. End should return true if |
- // everything is okay, or false if an error has occurred and parsing |
- // should stop. |
- virtual bool End() = 0; |
- |
- // Handler functions for Linux C++ exception handling data. These are |
- // only called if the data includes 'z' augmentation strings. |
- |
- // The Linux C++ ABI uses an extension of the DWARF CFI format to |
- // walk the stack to propagate exceptions from the throw to the |
- // appropriate catch, and do the appropriate cleanups along the way. |
- // CFI entries used for exception handling have two additional data |
- // associated with them: |
- // |
- // - The "language-specific data area" describes which exception |
- // types the function has 'catch' clauses for, and indicates how |
- // to go about re-entering the function at the appropriate catch |
- // clause. If the exception is not caught, it describes the |
- // destructors that must run before the frame is popped. |
- // |
- // - The "personality routine" is responsible for interpreting the |
- // language-specific data area's contents, and deciding whether |
- // the exception should continue to propagate down the stack, |
- // perhaps after doing some cleanup for this frame, or whether the |
- // exception will be caught here. |
- // |
- // In principle, the language-specific data area is opaque to |
- // everybody but the personality routine. In practice, these values |
- // may be useful or interesting to readers with extra context, and |
- // we have to at least skip them anyway, so we might as well report |
- // them to the handler. |
- |
- // This entry's exception handling personality routine's address is |
- // ADDRESS. If INDIRECT is true, then ADDRESS is the address at |
- // which the routine's address is stored. The default definition for |
- // this handler function simply returns true, allowing parsing of |
- // the entry to continue. |
- virtual bool PersonalityRoutine(uint64 address, bool indirect) { |
- return true; |
- } |
- |
- // This entry's language-specific data area (LSDA) is located at |
- // ADDRESS. If INDIRECT is true, then ADDRESS is the address at |
- // which the area's address is stored. The default definition for |
- // this handler function simply returns true, allowing parsing of |
- // the entry to continue. |
- virtual bool LanguageSpecificDataArea(uint64 address, bool indirect) { |
- return true; |
- } |
- |
- // This entry describes a signal trampoline --- this frame is the |
- // caller of a signal handler. The default definition for this |
- // handler function simply returns true, allowing parsing of the |
- // entry to continue. |
- // |
- // The best description of the rationale for and meaning of signal |
- // trampoline CFI entries seems to be in the GCC bug database: |
- // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26208 |
- virtual bool SignalHandler() { return true; } |
-}; |
- |
-// The CallFrameInfo class makes calls on an instance of this class to |
-// report errors or warn about problems in the data it is parsing. The |
-// default definitions of these methods print a message to stderr, but |
-// you can make a derived class that overrides them. |
-class CallFrameInfo::Reporter { |
- public: |
- // Create an error reporter which attributes troubles to the section |
- // named SECTION in FILENAME. |
- // |
- // Normally SECTION would be .debug_frame, but the Mac puts CFI data |
- // in a Mach-O section named __debug_frame. If we support |
- // Linux-style exception handling data, we could be reading an |
- // .eh_frame section. |
- Reporter(const string &filename, |
- const string §ion = ".debug_frame") |
- : filename_(filename), section_(section) { } |
- virtual ~Reporter() { } |
- |
- // The CFI entry at OFFSET ends too early to be well-formed. KIND |
- // indicates what kind of entry it is; KIND can be kUnknown if we |
- // haven't parsed enough of the entry to tell yet. |
- virtual void Incomplete(uint64 offset, CallFrameInfo::EntryKind kind); |
- |
- // The .eh_frame data has a four-byte zero at OFFSET where the next |
- // entry's length would be; this is a terminator. However, the buffer |
- // length as given to the CallFrameInfo constructor says there should be |
- // more data. |
- virtual void EarlyEHTerminator(uint64 offset); |
- |
- // The FDE at OFFSET refers to the CIE at CIE_OFFSET, but the |
- // section is not that large. |
- virtual void CIEPointerOutOfRange(uint64 offset, uint64 cie_offset); |
- |
- // The FDE at OFFSET refers to the CIE at CIE_OFFSET, but the entry |
- // there is not a CIE. |
- virtual void BadCIEId(uint64 offset, uint64 cie_offset); |
- |
- // The FDE at OFFSET refers to a CIE with version number VERSION, |
- // which we don't recognize. We cannot parse DWARF CFI if it uses |
- // a version number we don't recognize. |
- virtual void UnrecognizedVersion(uint64 offset, int version); |
- |
- // The FDE at OFFSET refers to a CIE with augmentation AUGMENTATION, |
- // which we don't recognize. We cannot parse DWARF CFI if it uses |
- // augmentations we don't recognize. |
- virtual void UnrecognizedAugmentation(uint64 offset, |
- const string &augmentation); |
- |
- // The pointer encoding ENCODING, specified by the CIE at OFFSET, is not |
- // a valid encoding. |
- virtual void InvalidPointerEncoding(uint64 offset, uint8 encoding); |
- |
- // The pointer encoding ENCODING, specified by the CIE at OFFSET, depends |
- // on a base address which has not been supplied. |
- virtual void UnusablePointerEncoding(uint64 offset, uint8 encoding); |
- |
- // The CIE at OFFSET contains a DW_CFA_restore instruction at |
- // INSN_OFFSET, which may not appear in a CIE. |
- virtual void RestoreInCIE(uint64 offset, uint64 insn_offset); |
- |
- // The entry at OFFSET, of kind KIND, has an unrecognized |
- // instruction at INSN_OFFSET. |
- virtual void BadInstruction(uint64 offset, CallFrameInfo::EntryKind kind, |
- uint64 insn_offset); |
- |
- // The instruction at INSN_OFFSET in the entry at OFFSET, of kind |
- // KIND, establishes a rule that cites the CFA, but we have not |
- // established a CFA rule yet. |
- virtual void NoCFARule(uint64 offset, CallFrameInfo::EntryKind kind, |
- uint64 insn_offset); |
- |
- // The instruction at INSN_OFFSET in the entry at OFFSET, of kind |
- // KIND, is a DW_CFA_restore_state instruction, but the stack of |
- // saved states is empty. |
- virtual void EmptyStateStack(uint64 offset, CallFrameInfo::EntryKind kind, |
- uint64 insn_offset); |
- |
- // The DW_CFA_remember_state instruction at INSN_OFFSET in the entry |
- // at OFFSET, of kind KIND, would restore a state that has no CFA |
- // rule, whereas the current state does have a CFA rule. This is |
- // bogus input, which the CallFrameInfo::Handler interface doesn't |
- // (and shouldn't) have any way to report. |
- virtual void ClearingCFARule(uint64 offset, CallFrameInfo::EntryKind kind, |
- uint64 insn_offset); |
- |
- protected: |
- // The name of the file whose CFI we're reading. |
- string filename_; |
- |
- // The name of the CFI section in that file. |
- string section_; |
-}; |
- |
-} // namespace dwarf2reader |
- |
-#endif // UTIL_DEBUGINFO_DWARF2READER_H__ |