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Diffstat (limited to 'lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp')
-rw-r--r--lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp89
1 files changed, 57 insertions, 32 deletions
diff --git a/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp b/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
index e12a24b..0d9385d 100644
--- a/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
+++ b/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
@@ -10,6 +10,7 @@
#include "MCTargetDesc/AArch64FixupKinds.h"
#include "MCTargetDesc/AArch64MCTargetDesc.h"
#include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
@@ -33,7 +34,7 @@ public:
: MCMachObjectTargetWriter(true /* is64Bit */, CPUType, CPUSubtype,
/*UseAggressiveSymbolFolding=*/true) {}
- void RecordRelocation(MachObjectWriter *Writer, const MCAssembler &Asm,
+ void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
const MCAsmLayout &Layout, const MCFragment *Fragment,
const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue) override;
@@ -112,8 +113,36 @@ bool AArch64MachObjectWriter::getAArch64FixupKindMachOInfo(
}
}
+static bool canUseLocalRelocation(const MCSectionMachO &Section,
+ const MCSymbol &Symbol, unsigned Log2Size) {
+ // Debug info sections can use local relocations.
+ if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
+ return true;
+
+ // Otherwise, only pointer sized relocations are supported.
+ if (Log2Size != 3)
+ return false;
+
+ // But only if they don't point to a few forbidden sections.
+ if (!Symbol.isInSection())
+ return true;
+ const MCSectionMachO &RefSec = cast<MCSectionMachO>(Symbol.getSection());
+ if (RefSec.getType() == MachO::S_CSTRING_LITERALS)
+ return false;
+
+ if (RefSec.getSegmentName() == "__DATA" &&
+ RefSec.getSectionName() == "__cfstring")
+ return false;
+
+ if (RefSec.getSegmentName() == "__DATA" &&
+ RefSec.getSectionName() == "__objc_classrefs")
+ return false;
+
+ return true;
+}
+
void AArch64MachObjectWriter::RecordRelocation(
- MachObjectWriter *Writer, const MCAssembler &Asm, const MCAsmLayout &Layout,
+ MachObjectWriter *Writer, MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue) {
unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
@@ -123,9 +152,9 @@ void AArch64MachObjectWriter::RecordRelocation(
unsigned Log2Size = 0;
int64_t Value = 0;
unsigned Index = 0;
- unsigned IsExtern = 0;
unsigned Type = 0;
unsigned Kind = Fixup.getKind();
+ const MCSymbolData *RelSymbol = nullptr;
FixupOffset += Fixup.getOffset();
@@ -171,10 +200,8 @@ void AArch64MachObjectWriter::RecordRelocation(
// FIXME: Should this always be extern?
// SymbolNum of 0 indicates the absolute section.
Type = MachO::ARM64_RELOC_UNSIGNED;
- Index = 0;
if (IsPCRel) {
- IsExtern = 1;
Asm.getContext().FatalError(Fixup.getLoc(),
"PC relative absolute relocation!");
@@ -198,15 +225,12 @@ void AArch64MachObjectWriter::RecordRelocation(
Layout.getSymbolOffset(&B_SD) ==
Layout.getFragmentOffset(Fragment) + Fixup.getOffset()) {
// SymB is the PC, so use a PC-rel pointer-to-GOT relocation.
- Index = A_Base->getIndex();
- IsExtern = 1;
Type = MachO::ARM64_RELOC_POINTER_TO_GOT;
IsPCRel = 1;
MachO::any_relocation_info MRE;
MRE.r_word0 = FixupOffset;
- MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
- (IsExtern << 27) | (Type << 28));
- Writer->addRelocation(Fragment->getParent(), MRE);
+ MRE.r_word1 = (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+ Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
return;
} else if (Target.getSymA()->getKind() != MCSymbolRefExpr::VK_None ||
Target.getSymB()->getKind() != MCSymbolRefExpr::VK_None)
@@ -252,26 +276,31 @@ void AArch64MachObjectWriter::RecordRelocation(
? 0
: Writer->getSymbolAddress(B_Base, Layout));
- Index = A_Base->getIndex();
- IsExtern = 1;
Type = MachO::ARM64_RELOC_UNSIGNED;
MachO::any_relocation_info MRE;
MRE.r_word0 = FixupOffset;
- MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
- (IsExtern << 27) | (Type << 28));
- Writer->addRelocation(Fragment->getParent(), MRE);
+ MRE.r_word1 = (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+ Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
- Index = B_Base->getIndex();
- IsExtern = 1;
+ RelSymbol = B_Base;
Type = MachO::ARM64_RELOC_SUBTRACTOR;
} else { // A + constant
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
- const MCSymbolData &SD = Asm.getSymbolData(*Symbol);
- const MCSymbolData *Base = Asm.getAtom(&SD);
const MCSectionMachO &Section = static_cast<const MCSectionMachO &>(
Fragment->getParent()->getSection());
+ bool CanUseLocalRelocation =
+ canUseLocalRelocation(Section, *Symbol, Log2Size);
+ if (Symbol->isTemporary() && (Value || !CanUseLocalRelocation)) {
+ const MCSection &Sec = Symbol->getSection();
+ if (!Asm.getContext().getAsmInfo()->isSectionAtomizableBySymbols(Sec))
+ Asm.addLocalUsedInReloc(*Symbol);
+ }
+
+ const MCSymbolData &SD = Asm.getSymbolData(*Symbol);
+ const MCSymbolData *Base = Asm.getAtom(&SD);
+
// If the symbol is a variable and we weren't able to get a Base for it
// (i.e., it's not in the symbol table associated with a section) resolve
// the relocation based its expansion instead.
@@ -310,16 +339,13 @@ void AArch64MachObjectWriter::RecordRelocation(
// sections, and for pointer-sized relocations (.quad), we allow section
// relocations. It's code sections that run into trouble.
if (Base) {
- Index = Base->getIndex();
- IsExtern = 1;
+ RelSymbol = Base;
// Add the local offset, if needed.
if (Base != &SD)
Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(Base);
} else if (Symbol->isInSection()) {
- // Pointer-sized relocations can use a local relocation. Otherwise,
- // we have to be in a debug info section.
- if (!Section.hasAttribute(MachO::S_ATTR_DEBUG) && Log2Size != 3)
+ if (!CanUseLocalRelocation)
Asm.getContext().FatalError(
Fixup.getLoc(),
"unsupported relocation of local symbol '" + Symbol->getName() +
@@ -329,7 +355,6 @@ void AArch64MachObjectWriter::RecordRelocation(
const MCSectionData &SymSD =
Asm.getSectionData(SD.getSymbol().getSection());
Index = SymSD.getOrdinal() + 1;
- IsExtern = 0;
Value += Writer->getSymbolAddress(&SD, Layout);
if (IsPCRel)
@@ -362,16 +387,16 @@ void AArch64MachObjectWriter::RecordRelocation(
MachO::any_relocation_info MRE;
MRE.r_word0 = FixupOffset;
- MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
- (IsExtern << 27) | (Type << 28));
- Writer->addRelocation(Fragment->getParent(), MRE);
+ MRE.r_word1 =
+ (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+ Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
// Now set up the Addend relocation.
Type = MachO::ARM64_RELOC_ADDEND;
Index = Value;
+ RelSymbol = nullptr;
IsPCRel = 0;
Log2Size = 2;
- IsExtern = 0;
// Put zero into the instruction itself. The addend is in the relocation.
Value = 0;
@@ -383,9 +408,9 @@ void AArch64MachObjectWriter::RecordRelocation(
// struct relocation_info (8 bytes)
MachO::any_relocation_info MRE;
MRE.r_word0 = FixupOffset;
- MRE.r_word1 = ((Index << 0) | (IsPCRel << 24) | (Log2Size << 25) |
- (IsExtern << 27) | (Type << 28));
- Writer->addRelocation(Fragment->getParent(), MRE);
+ MRE.r_word1 =
+ (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+ Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
}
MCObjectWriter *llvm::createAArch64MachObjectWriter(raw_ostream &OS,
generated by cgit v1.1 at 2024-12-22 10:58:37 +0000