// stringpool.h -- a string pool for gold -*- C++ -*-
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include <string>
#include <list>
+#include <vector>
#ifndef GOLD_STRINGPOOL_H
#define GOLD_STRINGPOOL_H
// single zero byte, as required for SHT_STRTAB sections. This
// conversion is only permitted after all strings have been added to
// the Stringpool. After doing this conversion, you can ask for the
-// offset of any string in the stringpool in the string table, and you
-// can write the resulting string table to an output file.
+// offset of any string (or any key) in the stringpool in the string
+// table, and you can write the resulting string table to an output
+// file.
// When a Stringpool is turned into a string table, then as an
// optimization it will reuse string suffixes to avoid duplicating
// string "abc" will be stored, and "bc" will be represented by an
// offset into the middle of the string "abc".
+
+// A simple chunked vector class--this is a subset of std::vector
+// which stores memory in chunks. We don't provide iterators, because
+// we don't need them.
+
+template<typename Element>
+class Chunked_vector
+{
+ public:
+ Chunked_vector()
+ : chunks_()
+ { }
+
+ // Clear the elements.
+ void
+ clear()
+ { this->chunks_.clear(); }
+
+ // Reserve elements.
+ void
+ reserve(unsigned int n)
+ {
+ n += chunk_size - 1;
+ while (n >= chunk_size)
+ {
+ this->chunks_.push_back(Element_vector());
+ this->chunks_.back().reserve(chunk_size);
+ n -= chunk_size;
+ }
+ }
+
+ // Get the number of elements.
+ size_t
+ size() const
+ {
+ if (this->chunks_.empty())
+ return 0;
+ else
+ return ((this->chunks_.size() - 1) * chunk_size
+ + this->chunks_.back().size());
+ }
+
+ // Push a new element on the back of the vector.
+ void
+ push_back(const Element& element)
+ {
+ if (this->chunks_.empty() || this->chunks_.back().size() == chunk_size)
+ {
+ this->chunks_.push_back(Element_vector());
+ this->chunks_.back().reserve(chunk_size);
+ }
+ this->chunks_.back().push_back(element);
+ }
+
+ // Return a reference to an entry in the vector.
+ Element&
+ operator[](size_t i)
+ { return this->chunks_[i / chunk_size][i % chunk_size]; }
+
+ const Element&
+ operator[](size_t i) const
+ { return this->chunks_[i / chunk_size][i % chunk_size]; }
+
+ private:
+ static const unsigned int chunk_size = 8192;
+
+ typedef std::vector<Element> Element_vector;
+ typedef std::vector<Element_vector> Chunk_vector;
+
+ Chunk_vector chunks_;
+};
+
+
// Stringpools are implemented in terms of Stringpool_template, which
// is generalized on the type of character used for the strings. Most
// uses will want the Stringpool type which uses char. Other cases
set_no_zero_null()
{ this->zero_null_ = false; }
+ // Indicate that this string pool should be optimized, even if not
+ // running with -O2.
+ void
+ set_optimize()
+ { this->optimize_ = true; }
+
// Add the string S to the pool. This returns a canonical permanent
// pointer to the string in the pool. If COPY is true, the string
// is copied into permanent storage. If PKEY is not NULL, this sets
const Stringpool_char*
add(const Stringpool_char* s, bool copy, Key* pkey);
- // Add the prefix of length LEN of string S to the pool.
+ // Add string S of length LEN characters to the pool. If COPY is
+ // true, S need not be null terminated.
const Stringpool_char*
- add_prefix(const Stringpool_char* s, size_t len, Key* pkey);
+ add_with_length(const Stringpool_char* s, size_t len, bool copy, Key* pkey);
// If the string S is present in the pool, return the canonical
// string pointer. Otherwise, return NULL. If PKEY is not NULL,
// Get the offset of the string S in the string table. This returns
// the offset in bytes, not in units of Stringpool_char. This may
// only be called after set_string_offsets has been called.
- off_t
+ section_offset_type
get_offset(const Stringpool_char* s) const;
// Get the offset of the string S in the string table.
- off_t
+ section_offset_type
get_offset(const std::basic_string<Stringpool_char>& s) const
- { return this->get_offset(s.c_str()); }
+ { return this->get_offset_with_length(s.c_str(), s.size()); }
+
+ // Get the offset of string S, with length LENGTH characters, in the
+ // string table.
+ section_offset_type
+ get_offset_with_length(const Stringpool_char* s, size_t length) const;
+
+ // Get the offset of the string with key K.
+ section_offset_type
+ get_offset_from_key(Key k) const
+ {
+ gold_assert(k <= this->key_to_offset_.size());
+ return this->key_to_offset_[k - 1];
+ }
// Get the size of the string table. This returns the number of
// bytes, not in units of Stringpool_char.
- off_t
+ section_size_type
get_strtab_size() const
{
gold_assert(this->strtab_size_ != 0);
// specified size. buffer_size should be at least
// get_strtab_size().
void
- write_to_buffer(unsigned char* buffer, size_t buffer_size);
+ write_to_buffer(unsigned char* buffer, section_size_type buffer_size);
// Dump statistical information to stderr.
void
size_t len;
// Allocated size of buffer.
size_t alc;
- // Buffer index.
- unsigned int index;
// Buffer.
char data[1];
};
// Copy a string into the buffers, returning a canonical string.
const Stringpool_char*
- add_string(const Stringpool_char*, size_t, Key*);
+ add_string(const Stringpool_char*, size_t);
// Return whether s1 is a suffix of s2.
static bool
// Note that these constructors are relatively expensive, because
// they compute the hash code.
- Hashkey(const Stringpool_char* s)
+ explicit Hashkey(const Stringpool_char* s)
: string(s), length(string_length(s)), hash_code(string_hash(s, length))
{ }
operator()(const Hashkey&, const Hashkey&) const;
};
- // The hash table is a map from strings to a pair of Key and string
- // table offsets. We only use the offsets if we turn this into an
- // string table section.
+ // The hash table is a map from strings to Keys.
- typedef std::pair<Key, off_t> Hashval;
+ typedef Key Hashval;
typedef Unordered_map<Hashkey, Hashval, Stringpool_hash,
Stringpool_eq> String_set_type;
operator()(const Stringpool_sort_info&, const Stringpool_sort_info&) const;
};
+ // Keys map to offsets via a Chunked_vector. We only use the
+ // offsets if we turn this into an string table section.
+ typedef Chunked_vector<section_offset_type> Key_to_offset;
+
// List of Stringdata structures.
typedef std::list<Stringdata*> Stringdata_list;
// Mapping from const char* to namepool entry.
String_set_type string_set_;
+ // Mapping from Key to string table offset.
+ Key_to_offset key_to_offset_;
// List of buffers.
Stringdata_list strings_;
// Size of string table.
- off_t strtab_size_;
- // Next Stringdata index.
- unsigned int next_index_;
- // Next key value for a string we don't copy.
- int next_uncopied_key_;
+ section_size_type strtab_size_;
// Whether to reserve offset 0 to hold the null string.
bool zero_null_;
+ // Whether to optimize the string table.
+ bool optimize_;
};
// The most common type of Stringpool.
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