llvm/lib/MC/MCELF.cpp
Jack Carter 77afbdce53 ELF symbol table field st_other support,
excluding visibility bits.

Generic STO handling at the Target level.

The st_other field of the ELF symbol table is one
byte in size. The first 2 bytes are used for generic
visibility and are currently handled by llvm.

The other six bits are processor specific and need 
to be set at the target level.

A couple of notes:

The new static methods for accessing and setting the "other"
flags in include/llvm/MC/MCELF.h match the style guide
and not the other methods in the file. I don't like the
inconsistency, but feel I should follow the prescribed 
lowerUpper() convention.

STO_ value definitions are not specified in gnu land as 
consistently as the STT_ and STB_ fields. Probably because
the latter were defined in a standards doc and the former
defined partially in code. I have stuck with the full byte
definition of the flags.

Contributer: Zoran Jovanovic




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175561 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-19 21:57:35 +00:00

87 lines
3.2 KiB
C++

//===- lib/MC/MCELF.cpp - MC ELF ------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements ELF object file writer information.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCELF.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCELFSymbolFlags.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/Support/ELF.h"
namespace llvm {
void MCELF::SetBinding(MCSymbolData &SD, unsigned Binding) {
assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
Binding == ELF::STB_WEAK);
uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
}
unsigned MCELF::GetBinding(const MCSymbolData &SD) {
uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
Binding == ELF::STB_WEAK);
return Binding;
}
void MCELF::SetType(MCSymbolData &SD, unsigned Type) {
assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
Type == ELF::STT_TLS || Type == ELF::STT_GNU_IFUNC);
uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STT_Shift);
SD.setFlags(OtherFlags | (Type << ELF_STT_Shift));
}
unsigned MCELF::GetType(const MCSymbolData &SD) {
uint32_t Type = (SD.getFlags() & (0xf << ELF_STT_Shift)) >> ELF_STT_Shift;
assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
Type == ELF::STT_TLS || Type == ELF::STT_GNU_IFUNC);
return Type;
}
// Visibility is stored in the first two bits of st_other
// st_other values are stored in the second byte of get/setFlags
void MCELF::SetVisibility(MCSymbolData &SD, unsigned Visibility) {
assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
uint32_t OtherFlags = SD.getFlags() & ~(0x3 << ELF_STV_Shift);
SD.setFlags(OtherFlags | (Visibility << ELF_STV_Shift));
}
unsigned MCELF::GetVisibility(MCSymbolData &SD) {
unsigned Visibility =
(SD.getFlags() & (0x3 << ELF_STV_Shift)) >> ELF_STV_Shift;
assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
return Visibility;
}
// Other is stored in the last six bits of st_other
// st_other values are stored in the second byte of get/setFlags
void MCELF::setOther(MCSymbolData &SD, unsigned Other) {
uint32_t OtherFlags = SD.getFlags() & ~(0x3f << ELF_Other_Shift);
SD.setFlags(OtherFlags | (Other << ELF_Other_Shift));
}
unsigned MCELF::getOther(MCSymbolData &SD) {
unsigned Other =
(SD.getFlags() & (0x3f << ELF_Other_Shift)) >> ELF_Other_Shift;
return Other;
}
}