Initial TOC support for PowerPC64 object creation
This patch adds initial PPC64 TOC MC object creation using the small mcmodel
(a single 64K TOC) adding the some TOC relocations (R_PPC64_TOC,
R_PPC64_TOC16, and R_PPC64_TOC16DS).
The addition of 'undefinedExplicitRelSym' hook on 'MCELFObjectTargetWriter'
is meant to avoid the creation of an unreferenced ".TOC." symbol (used in
the .odp creation) as well to set the R_PPC64_TOC relocation target as the
temporary ".TOC." symbol. On PPC64 ABI, the R_PPC64_TOC relocation should
not point to any symbol.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166677 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
index a197981..de3c352 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
@@ -11,6 +11,8 @@
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCValue.h"
using namespace llvm;
@@ -21,9 +23,15 @@
virtual ~PPCELFObjectWriter();
protected:
+ virtual unsigned getRelocTypeInner(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const;
virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
bool IsPCRel, bool IsRelocWithSymbol,
int64_t Addend) const;
+ virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const;
virtual void adjustFixupOffset(const MCFixup &Fixup, uint64_t &RelocOffset);
};
}
@@ -36,11 +44,13 @@
PPCELFObjectWriter::~PPCELFObjectWriter() {
}
-unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target,
- const MCFixup &Fixup,
- bool IsPCRel,
- bool IsRelocWithSymbol,
- int64_t Addend) const {
+unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const
+{
+ MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
+ MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
+
// determine the type of the relocation
unsigned Type;
if (IsPCRel) {
@@ -61,7 +71,7 @@
Type = ELF::R_PPC_ADDR24;
break;
case PPC::fixup_ppc_brcond14:
- Type = ELF::R_PPC_ADDR14_BRTAKEN; // XXX: or BRNTAKEN?_
+ Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_
break;
case PPC::fixup_ppc_ha16:
Type = ELF::R_PPC_ADDR16_HA;
@@ -72,6 +82,26 @@
case PPC::fixup_ppc_lo14:
Type = ELF::R_PPC_ADDR14;
break;
+ case PPC::fixup_ppc_toc:
+ Type = ELF::R_PPC64_TOC;
+ break;
+ case PPC::fixup_ppc_toc16:
+ Type = ELF::R_PPC64_TOC16;
+ break;
+ case PPC::fixup_ppc_toc16_ds:
+ Type = ELF::R_PPC64_TOC16_DS;
+ break;
+ case FK_Data_8:
+ switch (Modifier) {
+ default: llvm_unreachable("Unsupported Modifier");
+ case MCSymbolRefExpr::VK_PPC_TOC:
+ Type = ELF::R_PPC64_TOC;
+ break;
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_PPC64_ADDR64;
+ break;
+ }
+ break;
case FK_Data_4:
Type = ELF::R_PPC_ADDR32;
break;
@@ -83,6 +113,34 @@
return Type;
}
+unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel,
+ bool IsRelocWithSymbol,
+ int64_t Addend) const {
+ return getRelocTypeInner(Target, Fixup, IsPCRel);
+}
+
+const MCSymbol *PPCELFObjectWriter::undefinedExplicitRelSym(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ assert(Target.getSymA() && "SymA cannot be 0");
+ const MCSymbol &Symbol = Target.getSymA()->getSymbol().AliasedSymbol();
+
+ unsigned RelocType = getRelocTypeInner(Target, Fixup, IsPCRel);
+
+ // The .odp creation emits a relocation against the symbol ".TOC." which
+ // create a R_PPC64_TOC relocation. However the relocation symbol name
+ // in final object creation should be NULL, since the symbol does not
+ // really exist, it is just the reference to TOC base for the current
+ // object file.
+ bool EmitThisSym = RelocType != ELF::R_PPC64_TOC;
+
+ if (EmitThisSym && !Symbol.isTemporary())
+ return &Symbol;
+ return NULL;
+}
+
void PPCELFObjectWriter::
adjustFixupOffset(const MCFixup &Fixup, uint64_t &RelocOffset) {
switch ((unsigned)Fixup.getKind()) {