--- /dev/null
+// dwarf_reader.h -- parse dwarf2/3 debug information for gold -*- C++ -*-
+
+// Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#ifndef GOLD_DWARF_READER_H
+#define GOLD_DWARF_READER_H
+
+#include <vector>
+#include <map>
+
+#include "elfcpp.h"
+#include "elfcpp_swap.h"
+#include "dwarf.h"
+#include "reloc.h"
+
+namespace gold
+{
+
+template<int size, bool big_endian>
+class Track_relocs;
+struct LineStateMachine;
+
+uint64_t
+read_unsigned_LEB_128(const unsigned char* buffer, size_t* len);
+
+int64_t
+read_signed_LEB_128(const unsigned char* buffer, size_t* len);
+
+// We can't do better than to keep the offsets in a sorted vector.
+// Here, offset is the key, and file_num/line_num is the value.
+struct Offset_to_lineno_entry
+{
+ off_t offset;
+ int header_num; // which file-list to use (i.e. which .o file are we in)
+ int file_num; // a pointer into files_
+ int line_num; // the line number in the source file
+ // Offsets are unique within a section, so that's a sufficient sort key.
+ bool operator<(const Offset_to_lineno_entry& that) const
+ { return this->offset < that.offset; }
+};
+
+// This class is used to read the line information from the debugging
+// section of an object file.
+
+class Dwarf_line_info
+{
+ public:
+ Dwarf_line_info()
+ { }
+
+ virtual
+ ~Dwarf_line_info()
+ { }
+
+ // Given a section number and an offset, returns the associated
+ // file and line-number, as a string: "file:lineno". If unable
+ // to do the mapping, returns the empty string. You must call
+ // read_line_mappings() before calling this function.
+ std::string
+ addr2line(unsigned int shndx, off_t offset)
+ { return do_addr2line(shndx, offset); }
+
+ // A helper function for a single addr2line lookup. It also keeps a
+ // cache of the last CACHE_SIZE Dwarf_line_info objects it created;
+ // set to 0 not to cache at all. The larger CACHE_SIZE is, the more
+ // chance this routine won't have to re-create a Dwarf_line_info
+ // object for its addr2line computation; such creations are slow.
+ // NOTE: Not thread-safe, so only call from one thread at a time.
+ static std::string
+ one_addr2line(Object* object, unsigned int shndx, off_t offset,
+ size_t cache_size);
+
+ // This reclaims all the memory that one_addr2line may have cached.
+ // Use this when you know you will not be calling one_addr2line again.
+ static void
+ clear_addr2line_cache();
+
+ private:
+ virtual std::string
+ do_addr2line(unsigned int shndx, off_t offset) = 0;
+};
+
+template<int size, bool big_endian>
+class Sized_dwarf_line_info : public Dwarf_line_info
+{
+ public:
+ // Initializes a .debug_line reader for a given object file.
+ // If SHNDX is specified and non-negative, only read the debug
+ // information that pertains to the specified section.
+ Sized_dwarf_line_info(Object* object, unsigned int read_shndx = -1U);
+
+ private:
+ std::string
+ do_addr2line(unsigned int shndx, off_t offset);
+
+ // Start processing line info, and populates the offset_map_.
+ // If SHNDX is non-negative, only store debug information that
+ // pertains to the specified section.
+ void
+ read_line_mappings(Object*, unsigned int shndx);
+
+ // Reads the relocation section associated with .debug_line and
+ // stores relocation information in reloc_map_.
+ void
+ read_relocs(Object*);
+
+ // Looks in the symtab to see what section a symbol is in.
+ unsigned int
+ symbol_section(Object*, unsigned int sym,
+ typename elfcpp::Elf_types<size>::Elf_Addr* value,
+ bool* is_ordinary);
+
+ // Reads the DWARF2/3 header for this line info. Each takes as input
+ // a starting buffer position, and returns the ending position.
+ const unsigned char*
+ read_header_prolog(const unsigned char* lineptr);
+
+ const unsigned char*
+ read_header_tables(const unsigned char* lineptr);
+
+ // Reads the DWARF2/3 line information. If shndx is non-negative,
+ // discard all line information that doesn't pertain to the given
+ // section.
+ const unsigned char*
+ read_lines(const unsigned char* lineptr, unsigned int shndx);
+
+ // 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.
+ bool
+ process_one_opcode(const unsigned char* start,
+ struct LineStateMachine* lsm, size_t* len);
+
+ // Some parts of processing differ depending on whether the input
+ // was a .o file or not.
+ bool input_is_relobj();
+
+ // If we saw anything amiss while parsing, we set this to false.
+ // Then addr2line will always fail (rather than return possibly-
+ // corrupt data).
+ bool data_valid_;
+
+ // 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 Dwarf_line_infoHeader
+ {
+ off_t total_length;
+ int version;
+ off_t prologue_length;
+ int min_insn_length; // insn stands for instructin
+ bool default_is_stmt; // stmt stands for statement
+ signed char line_base;
+ int line_range;
+ unsigned char opcode_base;
+ std::vector<unsigned char> std_opcode_lengths;
+ int offset_size;
+ } header_;
+
+ // buffer is the buffer for our line info, starting at exactly where
+ // the line info to read is.
+ const unsigned char* buffer_;
+ const unsigned char* buffer_end_;
+
+ // This has relocations that point into buffer.
+ Track_relocs<size, big_endian> track_relocs_;
+
+ // This is used to figure out what section to apply a relocation to.
+ const unsigned char* symtab_buffer_;
+ section_size_type symtab_buffer_size_;
+
+ // Holds the directories and files as we see them. We have an array
+ // of directory-lists, one for each .o file we're reading (usually
+ // there will just be one, but there may be more if input is a .so).
+ std::vector<std::vector<std::string> > directories_;
+ // The first part is an index into directories_, the second the filename.
+ std::vector<std::vector< std::pair<int, std::string> > > files_;
+
+ // An index into the current directories_ and files_ vectors.
+ int current_header_index_;
+
+ // A sorted map from offset of the relocation target to the shndx
+ // and addend for the relocation.
+ typedef std::map<typename elfcpp::Elf_types<size>::Elf_Addr,
+ std::pair<unsigned int,
+ typename elfcpp::Elf_types<size>::Elf_Swxword> >
+ Reloc_map;
+ Reloc_map reloc_map_;
+
+ // We have a vector of offset->lineno entries for every input section.
+ typedef Unordered_map<unsigned int, std::vector<Offset_to_lineno_entry> >
+ Lineno_map;
+
+ Lineno_map line_number_map_;
+};
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_DWARF_READER_H)
projects / msp430-binutils.git / blobdiff