Ladybird/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-06-12 10:40:39 +09:00
Code Activity

LibELF: Move ELF hash functions to their own file (and make constexpr)

Browse source
This commit is contained in:
Andreas Kling 2021-02-23 18:19:47 +01:00
parent 145923bdc9
commit 37420f1baf
Notes: sideshowbarker 2024-07-18 21:59:18 +09:00
3 changed files with 67 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

35
Userland/Libraries/LibELF/DynamicObject.cpp
View file

@ -30,6 +30,7 @@
#include <AK/StringBuilder.h>
#include <LibELF/DynamicLoader.h>
#include <LibELF/DynamicObject.h>
#include <LibELF/Hashes.h>
#include <LibELF/exec_elf.h>
#include <string.h>
@ -248,36 +249,6 @@ DynamicObject::RelocationSection DynamicObject::plt_relocation_section() const
return RelocationSection(Section(*this, m_plt_relocation_offset_location, m_size_of_plt_relocation_entry_list, m_size_of_relocation_entry, "DT_JMPREL"));
}
u32 DynamicObject::HashSection::calculate_elf_hash(const StringView& name)
{
// SYSV ELF hash algorithm
// Note that the GNU HASH algorithm has less collisions
uint32_t hash = 0;
for (auto ch : name) {
hash = hash << 4;
hash += ch;
const uint32_t top_nibble_of_hash = hash & 0xF0000000U;
hash ^= top_nibble_of_hash >> 24;
hash &= ~top_nibble_of_hash;
}
return hash;
}
u32 DynamicObject::HashSection::calculate_gnu_hash(const StringView& name)
{
// GNU ELF hash algorithm
u32 hash = 5381;
for (auto ch : name)
hash = hash * 33 + ch;
return hash;
}
auto DynamicObject::HashSection::lookup_symbol(const StringView& name) const -> Optional<Symbol>
{
return (this->*(m_lookup_function))(name);
@ -285,7 +256,7 @@ auto DynamicObject::HashSection::lookup_symbol(const StringView& name) const ->
auto DynamicObject::HashSection::lookup_elf_symbol(const StringView& name) const -> Optional<Symbol>
{
u32 hash_value = calculate_elf_hash(name);
u32 hash_value = compute_sysv_hash(name);
u32* hash_table_begin = (u32*)address().as_ptr();
size_t num_buckets = hash_table_begin[0];
@ -328,7 +299,7 @@ auto DynamicObject::HashSection::lookup_gnu_symbol(const StringView& name) const
const u32* const buckets = &bloom_words[num_maskwords];
const u32* const chains = &buckets[num_buckets];
BloomWord hash1 = calculate_gnu_hash(name);
BloomWord hash1 = compute_gnu_hash(name);
BloomWord hash2 = hash1 >> shift2;
const BloomWord bitmask = (1 << (hash1 % bloom_word_size)) | (1 << (hash2 % bloom_word_size));