llvm/lib/Object/Object.cpp
Rafael Espindola c2966a3ac7 Remove getRelocationAddress.
Originally added in r139314.

Back then it didn't actually get the address, it got whatever value the
relocation used: address or offset.

The values in different object formats are:

* MachO: Always an offset.
* COFF: Always an address, but when talking about the virtual address of
  sections it says: "for simplicity, compilers should set this to zero".
* ELF: An offset for .o files and and address for .so files. In the case of the
  .so, the relocation in not linked to any section (sh_info is 0). We can't
  really compute an offset.

Some API mappings would be:

* Use getAddress for everything. It would be quite cumbersome. To compute the
  address elf has to follow sh_info, which can be corrupted and therefore the
  method has to return an ErrorOr. The address of the section is also the same
  for every relocation in a section, so we shouldn't have to check the error
  and fetch the value for every relocation.

* Use a getValue and make it up to the user to know what it is getting.

* Use a getOffset and:
 * Assert for dynamic ELF objects. That is a very peculiar case and it is
   probably fair to ask any tool that wants to support it to use ELF.h. The
   only tool we have that reads those (llvm-readobj) already does that. The
   only other use case I can think of is a dynamic linker.
 * Check that COFF .obj files have sections with zero virtual address spaces. If
   it turns out that some assembler/compiler produces these, we can change
   COFFObjectFile::getRelocationOffset to subtract it. Given COFF format,
   this can be done without the need for ErrorOr.

The getRelocationAddress method was never implemented for COFF. It also
had exactly one use in a very peculiar case: a shortcut for adding the
section value to a pcrel reloc on MachO.

Given that, I don't expect that there is any use out there of the C API. If
that is not the case, let me know and I will add it back with the implementation
inlined and do a proper deprecation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241450 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-06 14:55:37 +00:00

221 lines
6.5 KiB
C++

//===- Object.cpp - C bindings to the object file library--------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the C bindings to the file-format-independent object
// library.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallVector.h"
#include "llvm-c/Object.h"
#include "llvm/Object/ObjectFile.h"
using namespace llvm;
using namespace object;
inline OwningBinary<ObjectFile> *unwrap(LLVMObjectFileRef OF) {
return reinterpret_cast<OwningBinary<ObjectFile> *>(OF);
}
inline LLVMObjectFileRef wrap(const OwningBinary<ObjectFile> *OF) {
return reinterpret_cast<LLVMObjectFileRef>(
const_cast<OwningBinary<ObjectFile> *>(OF));
}
inline section_iterator *unwrap(LLVMSectionIteratorRef SI) {
return reinterpret_cast<section_iterator*>(SI);
}
inline LLVMSectionIteratorRef
wrap(const section_iterator *SI) {
return reinterpret_cast<LLVMSectionIteratorRef>
(const_cast<section_iterator*>(SI));
}
inline symbol_iterator *unwrap(LLVMSymbolIteratorRef SI) {
return reinterpret_cast<symbol_iterator*>(SI);
}
inline LLVMSymbolIteratorRef
wrap(const symbol_iterator *SI) {
return reinterpret_cast<LLVMSymbolIteratorRef>
(const_cast<symbol_iterator*>(SI));
}
inline relocation_iterator *unwrap(LLVMRelocationIteratorRef SI) {
return reinterpret_cast<relocation_iterator*>(SI);
}
inline LLVMRelocationIteratorRef
wrap(const relocation_iterator *SI) {
return reinterpret_cast<LLVMRelocationIteratorRef>
(const_cast<relocation_iterator*>(SI));
}
// ObjectFile creation
LLVMObjectFileRef LLVMCreateObjectFile(LLVMMemoryBufferRef MemBuf) {
std::unique_ptr<MemoryBuffer> Buf(unwrap(MemBuf));
ErrorOr<std::unique_ptr<ObjectFile>> ObjOrErr(
ObjectFile::createObjectFile(Buf->getMemBufferRef()));
std::unique_ptr<ObjectFile> Obj;
if (!ObjOrErr)
return nullptr;
auto *Ret = new OwningBinary<ObjectFile>(std::move(ObjOrErr.get()), std::move(Buf));
return wrap(Ret);
}
void LLVMDisposeObjectFile(LLVMObjectFileRef ObjectFile) {
delete unwrap(ObjectFile);
}
// ObjectFile Section iterators
LLVMSectionIteratorRef LLVMGetSections(LLVMObjectFileRef OF) {
OwningBinary<ObjectFile> *OB = unwrap(OF);
section_iterator SI = OB->getBinary()->section_begin();
return wrap(new section_iterator(SI));
}
void LLVMDisposeSectionIterator(LLVMSectionIteratorRef SI) {
delete unwrap(SI);
}
LLVMBool LLVMIsSectionIteratorAtEnd(LLVMObjectFileRef OF,
LLVMSectionIteratorRef SI) {
OwningBinary<ObjectFile> *OB = unwrap(OF);
return (*unwrap(SI) == OB->getBinary()->section_end()) ? 1 : 0;
}
void LLVMMoveToNextSection(LLVMSectionIteratorRef SI) {
++(*unwrap(SI));
}
void LLVMMoveToContainingSection(LLVMSectionIteratorRef Sect,
LLVMSymbolIteratorRef Sym) {
if (std::error_code ec = (*unwrap(Sym))->getSection(*unwrap(Sect)))
report_fatal_error(ec.message());
}
// ObjectFile Symbol iterators
LLVMSymbolIteratorRef LLVMGetSymbols(LLVMObjectFileRef OF) {
OwningBinary<ObjectFile> *OB = unwrap(OF);
symbol_iterator SI = OB->getBinary()->symbol_begin();
return wrap(new symbol_iterator(SI));
}
void LLVMDisposeSymbolIterator(LLVMSymbolIteratorRef SI) {
delete unwrap(SI);
}
LLVMBool LLVMIsSymbolIteratorAtEnd(LLVMObjectFileRef OF,
LLVMSymbolIteratorRef SI) {
OwningBinary<ObjectFile> *OB = unwrap(OF);
return (*unwrap(SI) == OB->getBinary()->symbol_end()) ? 1 : 0;
}
void LLVMMoveToNextSymbol(LLVMSymbolIteratorRef SI) {
++(*unwrap(SI));
}
// SectionRef accessors
const char *LLVMGetSectionName(LLVMSectionIteratorRef SI) {
StringRef ret;
if (std::error_code ec = (*unwrap(SI))->getName(ret))
report_fatal_error(ec.message());
return ret.data();
}
uint64_t LLVMGetSectionSize(LLVMSectionIteratorRef SI) {
return (*unwrap(SI))->getSize();
}
const char *LLVMGetSectionContents(LLVMSectionIteratorRef SI) {
StringRef ret;
if (std::error_code ec = (*unwrap(SI))->getContents(ret))
report_fatal_error(ec.message());
return ret.data();
}
uint64_t LLVMGetSectionAddress(LLVMSectionIteratorRef SI) {
return (*unwrap(SI))->getAddress();
}
LLVMBool LLVMGetSectionContainsSymbol(LLVMSectionIteratorRef SI,
LLVMSymbolIteratorRef Sym) {
return (*unwrap(SI))->containsSymbol(**unwrap(Sym));
}
// Section Relocation iterators
LLVMRelocationIteratorRef LLVMGetRelocations(LLVMSectionIteratorRef Section) {
relocation_iterator SI = (*unwrap(Section))->relocation_begin();
return wrap(new relocation_iterator(SI));
}
void LLVMDisposeRelocationIterator(LLVMRelocationIteratorRef SI) {
delete unwrap(SI);
}
LLVMBool LLVMIsRelocationIteratorAtEnd(LLVMSectionIteratorRef Section,
LLVMRelocationIteratorRef SI) {
return (*unwrap(SI) == (*unwrap(Section))->relocation_end()) ? 1 : 0;
}
void LLVMMoveToNextRelocation(LLVMRelocationIteratorRef SI) {
++(*unwrap(SI));
}
// SymbolRef accessors
const char *LLVMGetSymbolName(LLVMSymbolIteratorRef SI) {
ErrorOr<StringRef> Ret = (*unwrap(SI))->getName();
if (std::error_code EC = Ret.getError())
report_fatal_error(EC.message());
return Ret->data();
}
uint64_t LLVMGetSymbolAddress(LLVMSymbolIteratorRef SI) {
ErrorOr<uint64_t> Ret = (*unwrap(SI))->getAddress();
if (std::error_code EC = Ret.getError())
report_fatal_error(EC.message());
return *Ret;
}
uint64_t LLVMGetSymbolSize(LLVMSymbolIteratorRef SI) {
return (*unwrap(SI))->getCommonSize();
}
// RelocationRef accessors
uint64_t LLVMGetRelocationOffset(LLVMRelocationIteratorRef RI) {
return (*unwrap(RI))->getOffset();
}
LLVMSymbolIteratorRef LLVMGetRelocationSymbol(LLVMRelocationIteratorRef RI) {
symbol_iterator ret = (*unwrap(RI))->getSymbol();
return wrap(new symbol_iterator(ret));
}
uint64_t LLVMGetRelocationType(LLVMRelocationIteratorRef RI) {
return (*unwrap(RI))->getType();
}
// NOTE: Caller takes ownership of returned string.
const char *LLVMGetRelocationTypeName(LLVMRelocationIteratorRef RI) {
SmallVector<char, 0> ret;
(*unwrap(RI))->getTypeName(ret);
char *str = static_cast<char*>(malloc(ret.size()));
std::copy(ret.begin(), ret.end(), str);
return str;
}
// NOTE: Caller takes ownership of returned string.
const char *LLVMGetRelocationValueString(LLVMRelocationIteratorRef RI) {
return strdup("");
}