Android: Add chrome-specific dynamic linker.

third_party/crazy_linker/crazy_linker/src/crazy_linker_elf_symbols.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CRAZY_LINKER_ELF_SYMBOLS_H
+#define CRAZY_LINKER_ELF_SYMBOLS_H
+
+#include <string.h>
+
+#include "elf_traits.h"
+
+namespace crazy {
+
+class ElfView;
+
+// An ElfSymbols instance holds information about symbols in a mapped ELF
+// binary.
+class ElfSymbols {
+ public:
+  ElfSymbols() { ::memset(this, 0, sizeof(*this)); }
+  ~ElfSymbols() {}
+
+  bool Init(const ElfView* view);
+
+  const ELF::Sym* LookupByName(const char* symbol_name) const;
+
+  const ELF::Sym* LookupById(size_t symbol_id) const {
+    return &symbol_table_[symbol_id];
+  }
+
+  const ELF::Sym* LookupByAddress(void* address, size_t load_bias) const;
+
+  // Returns true iff symbol with id |symbol_id| is weak.
+  bool IsWeakById(size_t symbol_id) const {
+    return ELF_ST_BIND(symbol_table_[symbol_id].st_info) == STB_WEAK;
+  }
+
+  const char* LookupNameById(size_t symbol_id) const {
+    const ELF::Sym* sym = LookupById(symbol_id);
+    if (!sym)
+      return NULL;
+    return string_table_ + sym->st_name;
+  }
+
+  void* LookupAddressByName(const char* symbol_name, size_t load_bias) const {
+    const ELF::Sym* sym = LookupByName(symbol_name);
+    if (!sym)
+      return NULL;
+    return reinterpret_cast<void*>(load_bias + sym->st_value);
+  }
+
+  bool LookupNearestByAddress(void* address,
+                              size_t load_bias,
+                              const char** sym_name,
+                              void** sym_addr,
+                              size_t* sym_size) const;
+
+  const char* GetStringById(size_t str_id) const {
+    return string_table_ + str_id;
+  }
+
+  // TODO(digit): Remove this once ElfRelocator is gone.
+  const ELF::Sym* symbol_table() const { return symbol_table_; }
+  const char* string_table() const { return string_table_; }
+
+ private:
+  const ELF::Sym* symbol_table_;
+  const char* string_table_;
+  ELF::Addr* hash_bucket_;
+  size_t hash_bucket_size_;
+  ELF::Addr* hash_chain_;
+  size_t hash_chain_size_;
+};
+
+}  // namespace crazy
+
+#endif  // CRAZY_LINKER_ELF_SYMBOLS_H