#include <vector>
#include <cstring>
+#include "elfcpp.h"
#include "symtab.h"
#include "dynobj.h"
namespace gold
{
+// Class Dynobj.
+
+// Return the string to use in a DT_NEEDED entry.
+
+const char*
+Dynobj::soname() const
+{
+ if (!this->soname_.empty())
+ return this->soname_.c_str();
+ return this->name().c_str();
+}
+
// Class Sized_dynobj.
template<int size, bool big_endian>
off_t offset,
const elfcpp::Ehdr<size, big_endian>& ehdr)
: Dynobj(name, input_file, offset),
- elf_file_(this, ehdr),
- soname_()
+ elf_file_(this, ehdr)
{
}
typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
- assert(shdr.get_sh_type() == type);
+ gold_assert(shdr.get_sh_type() == type);
if (shdr.get_sh_link() != link)
{
*view_info = shdr.get_sh_info();
}
-// Set soname_ if this shared object has a DT_SONAME tag. PSHDRS
-// points to the section headers. DYNAMIC_SHNDX is the section index
-// of the SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and STRTAB_SIZE
-// are the section index and contents of a string table which may be
-// the one associated with the SHT_DYNAMIC section.
+// Set the soname field if this shared object has a DT_SONAME tag.
+// PSHDRS points to the section headers. DYNAMIC_SHNDX is the section
+// index of the SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and
+// STRTAB_SIZE are the section index and contents of a string table
+// which may be the one associated with the SHT_DYNAMIC section.
template<int size, bool big_endian>
void
off_t strtab_size)
{
typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
- assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
+ gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
const off_t dynamic_size = dynamicshdr.get_sh_size();
const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
}
const char* strtab = reinterpret_cast<const char*>(strtabu);
- this->soname_ = std::string(strtab + val);
+ this->set_soname_string(strtab + val);
return;
}
{
// Get the dynamic symbols.
typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
- assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
+ gold_assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
dynsymshdr.get_sh_size());
unsigned int ndx,
const char* name) const
{
- assert(ndx < version_map->size());
+ gold_assert(ndx < version_map->size());
if ((*version_map)[ndx] != NULL)
{
fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
{
if (sd->symbols == NULL)
{
- assert(sd->symbol_names == NULL);
- assert(sd->versym == NULL && sd->verdef == NULL && sd->verneed == NULL);
+ gold_assert(sd->symbol_names == NULL);
+ gold_assert(sd->versym == NULL && sd->verdef == NULL
+ && sd->verneed == NULL);
return;
}
}
}
+// Given a vector of hash codes, compute the number of hash buckets to
+// use.
+
+unsigned int
+Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes,
+ bool for_gnu_hash_table)
+{
+ // FIXME: Implement optional hash table optimization.
+
+ // Array used to determine the number of hash table buckets to use
+ // based on the number of symbols there are. If there are fewer
+ // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3
+ // buckets, fewer than 37 we use 17 buckets, and so forth. We never
+ // use more than 32771 buckets. This is straight from the old GNU
+ // linker.
+ static const unsigned int buckets[] =
+ {
+ 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
+ 16411, 32771
+ };
+ const int buckets_count = sizeof buckets / sizeof buckets[0];
+
+ unsigned int symcount = hashcodes.size();
+ unsigned int ret = 1;
+ for (int i = 0; i < buckets_count; ++i)
+ {
+ if (symcount < buckets[i])
+ break;
+ ret = buckets[i];
+ }
+
+ if (for_gnu_hash_table && ret < 2)
+ ret = 2;
+
+ return ret;
+}
+
+// The standard ELF hash function. This hash function must not
+// change, as the dynamic linker uses it also.
+
+uint32_t
+Dynobj::elf_hash(const char* name)
+{
+ const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
+ uint32_t h = 0;
+ unsigned char c;
+ while ((c = *nameu++) != '\0')
+ {
+ h = (h << 4) + c;
+ uint32_t g = h & 0xf0000000;
+ if (g != 0)
+ {
+ h ^= g >> 24;
+ // The ELF ABI says h &= ~g, but using xor is equivalent in
+ // this case (since g was set from h) and may save one
+ // instruction.
+ h ^= g;
+ }
+ }
+ return h;
+}
+
+// Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
+// DYNSYMS is a vector with all the global dynamic symbols.
+// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
+// symbol table.
+
+void
+Dynobj::create_elf_hash_table(const Target* target,
+ const std::vector<Symbol*>& dynsyms,
+ unsigned int local_dynsym_count,
+ unsigned char** pphash,
+ unsigned int* phashlen)
+{
+ unsigned int dynsym_count = dynsyms.size();
+
+ // Get the hash values for all the symbols.
+ std::vector<uint32_t> dynsym_hashvals(dynsym_count);
+ for (unsigned int i = 0; i < dynsym_count; ++i)
+ dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name());
+
+ const unsigned int bucketcount =
+ Dynobj::compute_bucket_count(dynsym_hashvals, false);
+
+ std::vector<uint32_t> bucket(bucketcount);
+ std::vector<uint32_t> chain(local_dynsym_count + dynsym_count);
+
+ for (unsigned int i = 0; i < dynsym_count; ++i)
+ {
+ unsigned int dynsym_index = dynsyms[i]->dynsym_index();
+ unsigned int bucketpos = dynsym_hashvals[i] % bucketcount;
+ chain[dynsym_index] = bucket[bucketpos];
+ bucket[bucketpos] = dynsym_index;
+ }
+
+ unsigned int hashlen = ((2
+ + bucketcount
+ + local_dynsym_count
+ + dynsym_count)
+ * 4);
+ unsigned char* phash = new unsigned char[hashlen];
+
+ if (target->is_big_endian())
+ Dynobj::sized_create_elf_hash_table<true>(bucket, chain, phash, hashlen);
+ else
+ Dynobj::sized_create_elf_hash_table<false>(bucket, chain, phash, hashlen);
+
+ *pphash = phash;
+ *phashlen = hashlen;
+}
+
+// Fill in an ELF hash table.
+
+template<bool big_endian>
+void
+Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
+ const std::vector<uint32_t>& chain,
+ unsigned char* phash,
+ unsigned int hashlen)
+{
+ unsigned char* p = phash;
+
+ const unsigned int bucketcount = bucket.size();
+ const unsigned int chaincount = chain.size();
+
+ elfcpp::Swap<32, big_endian>::writeval(p, bucketcount);
+ p += 4;
+ elfcpp::Swap<32, big_endian>::writeval(p, chaincount);
+ p += 4;
+
+ for (unsigned int i = 0; i < bucketcount; ++i)
+ {
+ elfcpp::Swap<32, big_endian>::writeval(p, bucket[i]);
+ p += 4;
+ }
+
+ for (unsigned int i = 0; i < chaincount; ++i)
+ {
+ elfcpp::Swap<32, big_endian>::writeval(p, chain[i]);
+ p += 4;
+ }
+
+ gold_assert(static_cast<unsigned int>(p - phash) == hashlen);
+}
+
+// The hash function used for the GNU hash table. This hash function
+// must not change, as the dynamic linker uses it also.
+
+uint32_t
+Dynobj::gnu_hash(const char* name)
+{
+ const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
+ uint32_t h = 5381;
+ unsigned char c;
+ while ((c = *nameu++) != '\0')
+ h = (h << 5) + h + c;
+ return h;
+}
+
+// Create a GNU hash table, setting *PPHASH and *PHASHLEN. GNU hash
+// tables are an extension to ELF which are recognized by the GNU
+// dynamic linker. They are referenced using dynamic tag DT_GNU_HASH.
+// TARGET is the target. DYNSYMS is a vector with all the global
+// symbols which will be going into the dynamic symbol table.
+// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
+// symbol table.
+
+void
+Dynobj::create_gnu_hash_table(const Target* target,
+ const std::vector<Symbol*>& dynsyms,
+ unsigned int local_dynsym_count,
+ unsigned char** pphash,
+ unsigned int* phashlen)
+{
+ const unsigned int count = dynsyms.size();
+
+ // Sort the dynamic symbols into two vectors. Symbols which we do
+ // not want to put into the hash table we store into
+ // UNHASHED_DYNSYMS. Symbols which we do want to store we put into
+ // HASHED_DYNSYMS. DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS,
+ // and records the hash codes.
+
+ std::vector<Symbol*> unhashed_dynsyms;
+ unhashed_dynsyms.reserve(count);
+
+ std::vector<Symbol*> hashed_dynsyms;
+ hashed_dynsyms.reserve(count);
+
+ std::vector<uint32_t> dynsym_hashvals;
+ dynsym_hashvals.reserve(count);
+
+ for (unsigned int i = 0; i < count; ++i)
+ {
+ Symbol* sym = dynsyms[i];
+
+ // FIXME: Should put on unhashed_dynsyms if the symbol is
+ // hidden.
+ if (sym->is_undefined())
+ unhashed_dynsyms.push_back(sym);
+ else
+ {
+ hashed_dynsyms.push_back(sym);
+ dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name()));
+ }
+ }
+
+ // Put the unhashed symbols at the start of the global portion of
+ // the dynamic symbol table.
+ const unsigned int unhashed_count = unhashed_dynsyms.size();
+ unsigned int unhashed_dynsym_index = local_dynsym_count;
+ for (unsigned int i = 0; i < unhashed_count; ++i)
+ {
+ unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index);
+ ++unhashed_dynsym_index;
+ }
+
+ // For the actual data generation we call out to a templatized
+ // function.
+ int size = target->get_size();
+ bool big_endian = target->is_big_endian();
+ if (size == 32)
+ {
+ if (big_endian)
+ Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms,
+ dynsym_hashvals,
+ unhashed_dynsym_index,
+ pphash,
+ phashlen);
+ else
+ Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms,
+ dynsym_hashvals,
+ unhashed_dynsym_index,
+ pphash,
+ phashlen);
+ }
+ else if (size == 64)
+ {
+ if (big_endian)
+ Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms,
+ dynsym_hashvals,
+ unhashed_dynsym_index,
+ pphash,
+ phashlen);
+ else
+ Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms,
+ dynsym_hashvals,
+ unhashed_dynsym_index,
+ pphash,
+ phashlen);
+ }
+ else
+ gold_unreachable();
+}
+
+// Create the actual data for a GNU hash table. This is just a copy
+// of the code from the old GNU linker.
+
+template<int size, bool big_endian>
+void
+Dynobj::sized_create_gnu_hash_table(
+ const std::vector<Symbol*>& hashed_dynsyms,
+ const std::vector<uint32_t>& dynsym_hashvals,
+ unsigned int unhashed_dynsym_count,
+ unsigned char** pphash,
+ unsigned int* phashlen)
+{
+ if (hashed_dynsyms.empty())
+ {
+ // Special case for the empty hash table.
+ unsigned int hashlen = 5 * 4 + size / 8;
+ unsigned char* phash = new unsigned char[hashlen];
+ // One empty bucket.
+ elfcpp::Swap<32, big_endian>::writeval(phash, 1);
+ // Symbol index above unhashed symbols.
+ elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count);
+ // One word for bitmask.
+ elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1);
+ // Only bloom filter.
+ elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0);
+ // No valid hashes.
+ elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0);
+ // No hashes in only bucket.
+ elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0);
+
+ *phashlen = hashlen;
+ *pphash = phash;
+
+ return;
+ }
+
+ const unsigned int bucketcount =
+ Dynobj::compute_bucket_count(dynsym_hashvals, true);
+
+ const unsigned int nsyms = hashed_dynsyms.size();
+
+ uint32_t maskbitslog2 = 1;
+ uint32_t x = nsyms >> 1;
+ while (x != 0)
+ {
+ ++maskbitslog2;
+ x >>= 1;
+ }
+ if (maskbitslog2 < 3)
+ maskbitslog2 = 5;
+ else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0)
+ maskbitslog2 += 3;
+ else
+ maskbitslog2 += 2;
+
+ uint32_t shift1;
+ if (size == 32)
+ shift1 = 5;
+ else
+ {
+ if (maskbitslog2 == 5)
+ maskbitslog2 = 6;
+ shift1 = 6;
+ }
+ uint32_t mask = (1U << shift1) - 1U;
+ uint32_t shift2 = maskbitslog2;
+ uint32_t maskbits = 1U << maskbitslog2;
+ uint32_t maskwords = 1U << (maskbitslog2 - shift1);
+
+ typedef typename elfcpp::Elf_types<size>::Elf_WXword Word;
+ std::vector<Word> bitmask(maskwords);
+ std::vector<uint32_t> counts(bucketcount);
+ std::vector<uint32_t> indx(bucketcount);
+ uint32_t symindx = unhashed_dynsym_count;
+
+ // Count the number of times each hash bucket is used.
+ for (unsigned int i = 0; i < nsyms; ++i)
+ ++counts[dynsym_hashvals[i] % bucketcount];
+
+ unsigned int cnt = symindx;
+ for (unsigned int i = 0; i < bucketcount; ++i)
+ {
+ indx[i] = cnt;
+ cnt += counts[i];
+ }
+
+ unsigned int hashlen = (4 + bucketcount + nsyms) * 4;
+ hashlen += maskbits / 8;
+ unsigned char* phash = new unsigned char[hashlen];
+
+ elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount);
+ elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx);
+ elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords);
+ elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2);
+
+ unsigned char* p = phash + 16 + maskbits / 8;
+ for (unsigned int i = 0; i < bucketcount; ++i)
+ {
+ if (counts[i] == 0)
+ elfcpp::Swap<32, big_endian>::writeval(p, 0);
+ else
+ elfcpp::Swap<32, big_endian>::writeval(p, indx[i]);
+ p += 4;
+ }
+
+ for (unsigned int i = 0; i < nsyms; ++i)
+ {
+ Symbol* sym = hashed_dynsyms[i];
+ uint32_t hashval = dynsym_hashvals[i];
+
+ unsigned int bucket = hashval % bucketcount;
+ unsigned int val = ((hashval >> shift1)
+ & ((maskbits >> shift1) - 1));
+ bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask);
+ bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask);
+ val = hashval & ~ 1U;
+ if (counts[bucket] == 1)
+ {
+ // Last element terminates the chain.
+ val |= 1;
+ }
+ elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4,
+ val);
+ --counts[bucket];
+
+ sym->set_dynsym_index(indx[bucket]);
+ ++indx[bucket];
+ }
+
+ p = phash + 16;
+ for (unsigned int i = 0; i < maskwords; ++i)
+ {
+ elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]);
+ p += size / 8;
+ }
+
+ *phashlen = hashlen;
+ *pphash = phash;
+}
+
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones for implemented targets.
projects / thirdparty / binutils-gdb.git / blobdiff