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mirror of https://github.com/rui314/mold.git synced 2024-12-26 18:02:30 +03:00
mold/input_sections.cc
2021-05-31 01:11:45 +09:00

105 lines
2.8 KiB
C++

#include "mold.h"
#include <limits>
template <typename E>
void InputSection<E>::write_to(Context<E> &ctx, u8 *buf) {
if (shdr.sh_type == SHT_NOBITS || shdr.sh_size == 0)
return;
// Copy data
memcpy(buf, contents.data(), contents.size());
// Apply relocations
if (shdr.sh_flags & SHF_ALLOC)
apply_reloc_alloc(ctx, buf);
else
apply_reloc_nonalloc(ctx, buf);
// As a special case, .ctors and .dtors section contents are
// reversed. These sections are now obsolete and mapped to
// .init_array and .fini_array, but they have to be reversed to
// maintain the original semantics.
bool init_fini = output_section->name == ".init_array" ||
output_section->name == ".fini_array";
bool ctors_dtors = name().starts_with(".ctors") ||
name().starts_with(".dtors");
if (init_fini && ctors_dtors)
std::reverse((typename E::WordTy *)buf,
(typename E::WordTy *)(buf + shdr.sh_size));
}
template <typename E>
static i64 get_output_type(Context<E> &ctx) {
if (ctx.arg.shared)
return 0;
if (ctx.arg.pie)
return 1;
return 2;
}
template <typename E>
static i64 get_sym_type(Context<E> &ctx, Symbol<E> &sym) {
if (sym.is_absolute(ctx))
return 0;
if (!sym.is_imported)
return 1;
if (sym.get_type() != STT_FUNC)
return 2;
return 3;
}
template <typename E>
void InputSection<E>::dispatch(Context<E> &ctx, Action table[3][4],
u16 rel_type, i64 i) {
std::span<ElfRel<E>> rels = get_rels(ctx);
const ElfRel<E> &rel = rels[i];
Symbol<E> &sym = *file.symbols[rel.r_sym];
bool is_readonly = !(shdr.sh_flags & SHF_WRITE);
Action action = table[get_output_type(ctx)][get_sym_type(ctx, sym)];
switch (action) {
case NONE:
rel_types[i] = rel_type;
return;
case ERROR:
break;
case COPYREL:
if (!ctx.arg.z_copyreloc)
break;
if (sym.esym().st_visibility == STV_PROTECTED)
Error(ctx) << *this << ": cannot make copy relocation for "
<< " protected symbol '" << sym << "', defined in "
<< *sym.file;
sym.flags |= NEEDS_COPYREL;
rel_types[i] = rel_type;
return;
case PLT:
sym.flags |= NEEDS_PLT;
rel_types[i] = rel_type;
return;
case DYNREL:
if (is_readonly)
break;
sym.flags |= NEEDS_DYNSYM;
rel_types[i] = R_DYN;
file.num_dynrel++;
return;
case BASEREL:
if (is_readonly)
break;
rel_types[i] = R_BASEREL;
file.num_dynrel++;
return;
default:
unreachable(ctx);
}
Error(ctx) << *this << ": " << rel_to_string<E>(rel.r_type)
<< " relocation against symbol `" << sym
<< "' can not be used; recompile with -fPIE";
}
template class InputSection<X86_64>;
template class InputSection<I386>;