llvm-project/llvm/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
Victor Huang 652a8f150d [PowerPC][PCRelative] Thread Local Storage Support for Local Dynamic
This patch is the initial support for the Local Dynamic Thread Local Storage
model to produce code sequence and relocation correct to the ABI for the model
when using PC relative memory operations.

Differential Revision: https://reviews.llvm.org/D87721
2020-09-23 13:48:06 -05:00

489 lines
16 KiB
C++

//===-- PPCELFObjectWriter.cpp - PPC ELF Writer ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/PPCFixupKinds.h"
#include "MCTargetDesc/PPCMCExpr.h"
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
namespace {
class PPCELFObjectWriter : public MCELFObjectTargetWriter {
public:
PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI);
protected:
unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
const MCFixup &Fixup, bool IsPCRel) const override;
bool needsRelocateWithSymbol(const MCSymbol &Sym,
unsigned Type) const override;
};
}
PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI)
: MCELFObjectTargetWriter(Is64Bit, OSABI,
Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC,
/*HasRelocationAddend*/ true) {}
static MCSymbolRefExpr::VariantKind getAccessVariant(const MCValue &Target,
const MCFixup &Fixup) {
const MCExpr *Expr = Fixup.getValue();
if (Expr->getKind() != MCExpr::Target)
return Target.getAccessVariant();
switch (cast<PPCMCExpr>(Expr)->getKind()) {
case PPCMCExpr::VK_PPC_None:
return MCSymbolRefExpr::VK_None;
case PPCMCExpr::VK_PPC_LO:
return MCSymbolRefExpr::VK_PPC_LO;
case PPCMCExpr::VK_PPC_HI:
return MCSymbolRefExpr::VK_PPC_HI;
case PPCMCExpr::VK_PPC_HA:
return MCSymbolRefExpr::VK_PPC_HA;
case PPCMCExpr::VK_PPC_HIGH:
return MCSymbolRefExpr::VK_PPC_HIGH;
case PPCMCExpr::VK_PPC_HIGHA:
return MCSymbolRefExpr::VK_PPC_HIGHA;
case PPCMCExpr::VK_PPC_HIGHERA:
return MCSymbolRefExpr::VK_PPC_HIGHERA;
case PPCMCExpr::VK_PPC_HIGHER:
return MCSymbolRefExpr::VK_PPC_HIGHER;
case PPCMCExpr::VK_PPC_HIGHEST:
return MCSymbolRefExpr::VK_PPC_HIGHEST;
case PPCMCExpr::VK_PPC_HIGHESTA:
return MCSymbolRefExpr::VK_PPC_HIGHESTA;
}
llvm_unreachable("unknown PPCMCExpr kind");
}
unsigned PPCELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel) const {
MCFixupKind Kind = Fixup.getKind();
if (Kind >= FirstLiteralRelocationKind)
return Kind - FirstLiteralRelocationKind;
MCSymbolRefExpr::VariantKind Modifier = getAccessVariant(Target, Fixup);
// determine the type of the relocation
unsigned Type;
if (IsPCRel) {
switch (Fixup.getTargetKind()) {
default:
llvm_unreachable("Unimplemented");
case PPC::fixup_ppc_br24:
case PPC::fixup_ppc_br24abs:
case PPC::fixup_ppc_br24_notoc:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_None:
Type = ELF::R_PPC_REL24;
break;
case MCSymbolRefExpr::VK_PLT:
Type = ELF::R_PPC_PLTREL24;
break;
case MCSymbolRefExpr::VK_PPC_LOCAL:
Type = ELF::R_PPC_LOCAL24PC;
break;
case MCSymbolRefExpr::VK_PPC_NOTOC:
Type = ELF::R_PPC64_REL24_NOTOC;
break;
}
break;
case PPC::fixup_ppc_brcond14:
case PPC::fixup_ppc_brcond14abs:
Type = ELF::R_PPC_REL14;
break;
case PPC::fixup_ppc_half16:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_None:
Type = ELF::R_PPC_REL16;
break;
case MCSymbolRefExpr::VK_PPC_LO:
Type = ELF::R_PPC_REL16_LO;
break;
case MCSymbolRefExpr::VK_PPC_HI:
Type = ELF::R_PPC_REL16_HI;
break;
case MCSymbolRefExpr::VK_PPC_HA:
Type = ELF::R_PPC_REL16_HA;
break;
}
break;
case PPC::fixup_ppc_half16ds:
Target.print(errs());
errs() << '\n';
report_fatal_error("Invalid PC-relative half16ds relocation");
case PPC::fixup_ppc_pcrel34:
switch (Modifier) {
default:
llvm_unreachable("Unsupported Modifier for fixup_ppc_pcrel34");
case MCSymbolRefExpr::VK_PCREL:
Type = ELF::R_PPC64_PCREL34;
break;
case MCSymbolRefExpr::VK_PPC_GOT_PCREL:
Type = ELF::R_PPC64_GOT_PCREL34;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_PCREL:
Type = ELF::R_PPC64_GOT_TLSGD_PCREL34;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_PCREL:
Type = ELF::R_PPC64_GOT_TLSLD_PCREL34;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL_PCREL:
Type = ELF::R_PPC64_GOT_TPREL_PCREL34;
break;
}
break;
case FK_Data_4:
case FK_PCRel_4:
Type = ELF::R_PPC_REL32;
break;
case FK_Data_8:
case FK_PCRel_8:
Type = ELF::R_PPC64_REL64;
break;
}
} else {
switch (Fixup.getTargetKind()) {
default: llvm_unreachable("invalid fixup kind!");
case PPC::fixup_ppc_br24abs:
Type = ELF::R_PPC_ADDR24;
break;
case PPC::fixup_ppc_brcond14abs:
Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_
break;
case PPC::fixup_ppc_half16:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_None:
Type = ELF::R_PPC_ADDR16;
break;
case MCSymbolRefExpr::VK_PPC_LO:
Type = ELF::R_PPC_ADDR16_LO;
break;
case MCSymbolRefExpr::VK_PPC_HI:
Type = ELF::R_PPC_ADDR16_HI;
break;
case MCSymbolRefExpr::VK_PPC_HA:
Type = ELF::R_PPC_ADDR16_HA;
break;
case MCSymbolRefExpr::VK_PPC_HIGH:
Type = ELF::R_PPC64_ADDR16_HIGH;
break;
case MCSymbolRefExpr::VK_PPC_HIGHA:
Type = ELF::R_PPC64_ADDR16_HIGHA;
break;
case MCSymbolRefExpr::VK_PPC_HIGHER:
Type = ELF::R_PPC64_ADDR16_HIGHER;
break;
case MCSymbolRefExpr::VK_PPC_HIGHERA:
Type = ELF::R_PPC64_ADDR16_HIGHERA;
break;
case MCSymbolRefExpr::VK_PPC_HIGHEST:
Type = ELF::R_PPC64_ADDR16_HIGHEST;
break;
case MCSymbolRefExpr::VK_PPC_HIGHESTA:
Type = ELF::R_PPC64_ADDR16_HIGHESTA;
break;
case MCSymbolRefExpr::VK_GOT:
Type = ELF::R_PPC_GOT16;
break;
case MCSymbolRefExpr::VK_PPC_GOT_LO:
Type = ELF::R_PPC_GOT16_LO;
break;
case MCSymbolRefExpr::VK_PPC_GOT_HI:
Type = ELF::R_PPC_GOT16_HI;
break;
case MCSymbolRefExpr::VK_PPC_GOT_HA:
Type = ELF::R_PPC_GOT16_HA;
break;
case MCSymbolRefExpr::VK_PPC_TOC:
Type = ELF::R_PPC64_TOC16;
break;
case MCSymbolRefExpr::VK_PPC_TOC_LO:
Type = ELF::R_PPC64_TOC16_LO;
break;
case MCSymbolRefExpr::VK_PPC_TOC_HI:
Type = ELF::R_PPC64_TOC16_HI;
break;
case MCSymbolRefExpr::VK_PPC_TOC_HA:
Type = ELF::R_PPC64_TOC16_HA;
break;
case MCSymbolRefExpr::VK_TPREL:
Type = ELF::R_PPC_TPREL16;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_LO:
Type = ELF::R_PPC_TPREL16_LO;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HI:
Type = ELF::R_PPC_TPREL16_HI;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HA:
Type = ELF::R_PPC_TPREL16_HA;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGH:
Type = ELF::R_PPC64_TPREL16_HIGH;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGHA:
Type = ELF::R_PPC64_TPREL16_HIGHA;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER:
Type = ELF::R_PPC64_TPREL16_HIGHER;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA:
Type = ELF::R_PPC64_TPREL16_HIGHERA;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST:
Type = ELF::R_PPC64_TPREL16_HIGHEST;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA:
Type = ELF::R_PPC64_TPREL16_HIGHESTA;
break;
case MCSymbolRefExpr::VK_DTPREL:
Type = ELF::R_PPC64_DTPREL16;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
Type = ELF::R_PPC64_DTPREL16_LO;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HI:
Type = ELF::R_PPC64_DTPREL16_HI;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HA:
Type = ELF::R_PPC64_DTPREL16_HA;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGH:
Type = ELF::R_PPC64_DTPREL16_HIGH;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHA:
Type = ELF::R_PPC64_DTPREL16_HIGHA;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER:
Type = ELF::R_PPC64_DTPREL16_HIGHER;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA:
Type = ELF::R_PPC64_DTPREL16_HIGHERA;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST:
Type = ELF::R_PPC64_DTPREL16_HIGHEST;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA:
Type = ELF::R_PPC64_DTPREL16_HIGHESTA;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD:
if (is64Bit())
Type = ELF::R_PPC64_GOT_TLSGD16;
else
Type = ELF::R_PPC_GOT_TLSGD16;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
Type = ELF::R_PPC64_GOT_TLSGD16_LO;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
Type = ELF::R_PPC64_GOT_TLSGD16_HI;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
Type = ELF::R_PPC64_GOT_TLSGD16_HA;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
if (is64Bit())
Type = ELF::R_PPC64_GOT_TLSLD16;
else
Type = ELF::R_PPC_GOT_TLSLD16;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
Type = ELF::R_PPC64_GOT_TLSLD16_LO;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
Type = ELF::R_PPC64_GOT_TLSLD16_HI;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
Type = ELF::R_PPC64_GOT_TLSLD16_HA;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
/* We don't have R_PPC64_GOT_TPREL16, but since GOT offsets
are always 4-aligned, we can use R_PPC64_GOT_TPREL16_DS. */
Type = ELF::R_PPC64_GOT_TPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
/* We don't have R_PPC64_GOT_TPREL16_LO, but since GOT offsets
are always 4-aligned, we can use R_PPC64_GOT_TPREL16_LO_DS. */
Type = ELF::R_PPC64_GOT_TPREL16_LO_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI:
Type = ELF::R_PPC64_GOT_TPREL16_HI;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
/* We don't have R_PPC64_GOT_DTPREL16, but since GOT offsets
are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_DS. */
Type = ELF::R_PPC64_GOT_DTPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
/* We don't have R_PPC64_GOT_DTPREL16_LO, but since GOT offsets
are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_LO_DS. */
Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA:
Type = ELF::R_PPC64_GOT_TPREL16_HA;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI:
Type = ELF::R_PPC64_GOT_DTPREL16_HI;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA:
Type = ELF::R_PPC64_GOT_DTPREL16_HA;
break;
}
break;
case PPC::fixup_ppc_half16ds:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_None:
Type = ELF::R_PPC64_ADDR16_DS;
break;
case MCSymbolRefExpr::VK_PPC_LO:
Type = ELF::R_PPC64_ADDR16_LO_DS;
break;
case MCSymbolRefExpr::VK_GOT:
Type = ELF::R_PPC64_GOT16_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_LO:
Type = ELF::R_PPC64_GOT16_LO_DS;
break;
case MCSymbolRefExpr::VK_PPC_TOC:
Type = ELF::R_PPC64_TOC16_DS;
break;
case MCSymbolRefExpr::VK_PPC_TOC_LO:
Type = ELF::R_PPC64_TOC16_LO_DS;
break;
case MCSymbolRefExpr::VK_TPREL:
Type = ELF::R_PPC64_TPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_TPREL_LO:
Type = ELF::R_PPC64_TPREL16_LO_DS;
break;
case MCSymbolRefExpr::VK_DTPREL:
Type = ELF::R_PPC64_DTPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_DTPREL_LO:
Type = ELF::R_PPC64_DTPREL16_LO_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL:
Type = ELF::R_PPC64_GOT_TPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO:
Type = ELF::R_PPC64_GOT_TPREL16_LO_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL:
Type = ELF::R_PPC64_GOT_DTPREL16_DS;
break;
case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO:
Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS;
break;
}
break;
case PPC::fixup_ppc_nofixup:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_PPC_TLSGD:
if (is64Bit())
Type = ELF::R_PPC64_TLSGD;
else
Type = ELF::R_PPC_TLSGD;
break;
case MCSymbolRefExpr::VK_PPC_TLSLD:
if (is64Bit())
Type = ELF::R_PPC64_TLSLD;
else
Type = ELF::R_PPC_TLSLD;
break;
case MCSymbolRefExpr::VK_PPC_TLS:
if (is64Bit())
Type = ELF::R_PPC64_TLS;
else
Type = ELF::R_PPC_TLS;
break;
case MCSymbolRefExpr::VK_PPC_TLS_PCREL:
Type = ELF::R_PPC64_TLS;
break;
}
break;
case PPC::fixup_ppc_imm34:
switch (Modifier) {
default:
report_fatal_error("Unsupported Modifier for fixup_ppc_imm34.");
case MCSymbolRefExpr::VK_DTPREL:
Type = ELF::R_PPC64_DTPREL34;
break;
case MCSymbolRefExpr::VK_TPREL:
Type = ELF::R_PPC64_TPREL34;
break;
}
break;
case FK_Data_8:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_PPC_TOCBASE:
Type = ELF::R_PPC64_TOC;
break;
case MCSymbolRefExpr::VK_None:
Type = ELF::R_PPC64_ADDR64;
break;
case MCSymbolRefExpr::VK_PPC_DTPMOD:
Type = ELF::R_PPC64_DTPMOD64;
break;
case MCSymbolRefExpr::VK_TPREL:
Type = ELF::R_PPC64_TPREL64;
break;
case MCSymbolRefExpr::VK_DTPREL:
Type = ELF::R_PPC64_DTPREL64;
break;
}
break;
case FK_Data_4:
Type = ELF::R_PPC_ADDR32;
break;
case FK_Data_2:
Type = ELF::R_PPC_ADDR16;
break;
}
}
return Type;
}
bool PPCELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym,
unsigned Type) const {
switch (Type) {
default:
return false;
case ELF::R_PPC_REL24:
case ELF::R_PPC64_REL24_NOTOC:
// If the target symbol has a local entry point, we must keep the
// target symbol to preserve that information for the linker.
// The "other" values are stored in the last 6 bits of the second byte.
// The traditional defines for STO values assume the full byte and thus
// the shift to pack it.
unsigned Other = cast<MCSymbolELF>(Sym).getOther() << 2;
return (Other & ELF::STO_PPC64_LOCAL_MASK) != 0;
}
}
std::unique_ptr<MCObjectTargetWriter>
llvm::createPPCELFObjectWriter(bool Is64Bit, uint8_t OSABI) {
return std::make_unique<PPCELFObjectWriter>(Is64Bit, OSABI);
}