Add r224985 back with fixes.
The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.
Original message:
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 226503
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
index 27cbac9..423da65 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -317,42 +317,6 @@
MachO::CPU_SUBTYPE_ARM64_ALL);
}
- bool doesSectionRequireSymbols(const MCSection &Section) const override {
- // Any section for which the linker breaks things into atoms needs to
- // preserve symbols, including assembler local symbols, to identify
- // those atoms. These sections are:
- // Sections of type:
- //
- // S_CSTRING_LITERALS (e.g. __cstring)
- // S_LITERAL_POINTERS (e.g. objc selector pointers)
- // S_16BYTE_LITERALS, S_8BYTE_LITERALS, S_4BYTE_LITERALS
- //
- // Sections named:
- //
- // __TEXT,__eh_frame
- // __TEXT,__ustring
- // __DATA,__cfstring
- // __DATA,__objc_classrefs
- // __DATA,__objc_catlist
- //
- // FIXME: It would be better if the compiler used actual linker local
- // symbols for each of these sections rather than preserving what
- // are ostensibly assembler local symbols.
- const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section);
- return (SMO.getType() == MachO::S_CSTRING_LITERALS ||
- SMO.getType() == MachO::S_4BYTE_LITERALS ||
- SMO.getType() == MachO::S_8BYTE_LITERALS ||
- SMO.getType() == MachO::S_16BYTE_LITERALS ||
- SMO.getType() == MachO::S_LITERAL_POINTERS ||
- (SMO.getSegmentName() == "__TEXT" &&
- (SMO.getSectionName() == "__eh_frame" ||
- SMO.getSectionName() == "__ustring")) ||
- (SMO.getSegmentName() == "__DATA" &&
- (SMO.getSectionName() == "__cfstring" ||
- SMO.getSectionName() == "__objc_classrefs" ||
- SMO.getSectionName() == "__objc_catlist")));
- }
-
/// \brief Generate the compact unwind encoding from the CFI directives.
uint32_t generateCompactUnwindEncoding(
ArrayRef<MCCFIInstruction> Instrs) const override {
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
index e12a24b..6c554fd 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
+++ b/llvm/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 @@
: 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 +113,32 @@
}
}
+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;
+
+ 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 +148,9 @@
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 +196,8 @@
// 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 +221,12 @@
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 +272,31 @@
? 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 +335,13 @@
// 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 +351,6 @@
const MCSectionData &SymSD =
Asm.getSectionData(SD.getSymbol().getSection());
Index = SymSD.getOrdinal() + 1;
- IsExtern = 0;
Value += Writer->getSymbolAddress(&SD, Layout);
if (IsPCRel)
@@ -362,16 +383,16 @@
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 +404,9 @@
// 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,
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
index 7da5003..3187d36 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
@@ -54,10 +54,10 @@
: MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
/*UseAggressiveSymbolFolding=*/true) {}
- void RecordRelocation(MachObjectWriter *Writer,
- const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue) override;
+ void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+ const MCAsmLayout &Layout, const MCFragment *Fragment,
+ const MCFixup &Fixup, MCValue Target,
+ uint64_t &FixedValue) override;
};
}
@@ -232,7 +232,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value2;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
}
MachO::any_relocation_info MRE;
@@ -243,7 +243,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
}
void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
@@ -297,7 +297,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value2;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
}
MachO::any_relocation_info MRE;
@@ -307,7 +307,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
}
bool ARMMachObjectWriter::requiresExternRelocation(MachObjectWriter *Writer,
@@ -351,11 +351,10 @@
}
void ARMMachObjectWriter::RecordRelocation(MachObjectWriter *Writer,
- const MCAssembler &Asm,
+ MCAssembler &Asm,
const MCAsmLayout &Layout,
const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
+ const MCFixup &Fixup, MCValue Target,
uint64_t &FixedValue) {
unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
unsigned Log2Size;
@@ -401,8 +400,8 @@
// See <reloc.h>.
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
unsigned Index = 0;
- unsigned IsExtern = 0;
unsigned Type = 0;
+ const MCSymbolData *RelSymbol = nullptr;
if (Target.isAbsolute()) { // constant
// FIXME!
@@ -422,8 +421,7 @@
// Check whether we need an external or internal relocation.
if (requiresExternRelocation(Writer, Asm, *Fragment, RelocType, SD,
FixedValue)) {
- IsExtern = 1;
- Index = SD->getIndex();
+ RelSymbol = SD;
// For external relocations, make sure to offset the fixup value to
// compensate for the addend of the symbol address, if it was
@@ -447,11 +445,8 @@
// 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));
+ MRE.r_word1 =
+ (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
// Even when it's not a scattered relocation, movw/movt always uses
// a PAIR relocation.
@@ -476,10 +471,10 @@
(Log2Size << 25) |
(MachO::ARM_RELOC_PAIR << 28));
- Writer->addRelocation(Fragment->getParent(), MREPair);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MREPair);
}
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
}
MCObjectWriter *llvm::createARMMachObjectWriter(raw_ostream &OS,
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp
index df2f14a..f7259b9 100644
--- a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp
+++ b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMachObjectWriter.cpp
@@ -41,7 +41,7 @@
: MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
/*UseAggressiveSymbolFolding=*/Is64Bit) {}
- 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 {
@@ -282,7 +282,7 @@
MachO::any_relocation_info MRE;
makeScatteredRelocationInfo(MRE, other_half, MachO::GENERIC_RELOC_PAIR,
Log2Size, IsPCRel, Value2);
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
} else {
// If the offset is more than 24-bits, it won't fit in a scattered
// relocation offset field, so we fall back to using a non-scattered
@@ -296,7 +296,7 @@
}
MachO::any_relocation_info MRE;
makeScatteredRelocationInfo(MRE, FixupOffset, Type, Log2Size, IsPCRel, Value);
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
return true;
}
@@ -331,9 +331,9 @@
// See <reloc.h>.
const uint32_t FixupOffset = getFixupOffset(Layout, Fragment, Fixup);
unsigned Index = 0;
- unsigned IsExtern = 0;
unsigned Type = RelocType;
+ const MCSymbolData *RelSymbol = nullptr;
if (Target.isAbsolute()) { // constant
// SymbolNum of 0 indicates the absolute section.
//
@@ -355,8 +355,7 @@
// Check whether we need an external or internal relocation.
if (Writer->doesSymbolRequireExternRelocation(SD)) {
- IsExtern = 1;
- Index = SD->getIndex();
+ RelSymbol = SD;
// For external relocations, make sure to offset the fixup value to
// compensate for the addend of the symbol address, if it was
// undefined. This occurs with weak definitions, for example.
@@ -375,9 +374,8 @@
// struct relocation_info (8 bytes)
MachO::any_relocation_info MRE;
- makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, IsExtern,
- Type);
- Writer->addRelocation(Fragment->getParent(), MRE);
+ makeRelocationInfo(MRE, FixupOffset, Index, IsPCRel, Log2Size, false, Type);
+ Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
}
MCObjectWriter *llvm::createPPCMachObjectWriter(raw_ostream &OS, bool Is64Bit,
diff --git a/llvm/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp b/llvm/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp
index 5fb311b..d0c634f 100644
--- a/llvm/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp
+++ b/llvm/lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp
@@ -29,7 +29,7 @@
const MCAsmLayout &Layout) override {
//XXX: Implement if necessary.
}
- void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ void RecordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
MCValue Target, bool &IsPCRel,
uint64_t &FixedValue) override {
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index 164b419..719b761 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -777,19 +777,6 @@
MachO::CPU_TYPE_X86_64, Subtype);
}
- bool doesSectionRequireSymbols(const MCSection &Section) const override {
- // Temporary labels in the string literals sections require symbols. The
- // issue is that the x86_64 relocation format does not allow symbol +
- // offset, and so the linker does not have enough information to resolve the
- // access to the appropriate atom unless an external relocation is used. For
- // non-cstring sections, we expect the compiler to use a non-temporary label
- // for anything that could have an addend pointing outside the symbol.
- //
- // See <rdar://problem/4765733>.
- const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(Section);
- return SMO.getType() == MachO::S_CSTRING_LITERALS;
- }
-
/// \brief Generate the compact unwind encoding for the CFI instructions.
uint32_t generateCompactUnwindEncoding(
ArrayRef<MCCFIInstruction> Instrs) const override {
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
index 67b0c89..7a83f4c 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
@@ -10,6 +10,7 @@
#include "MCTargetDesc/X86MCTargetDesc.h"
#include "MCTargetDesc/X86FixupKinds.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"
@@ -47,23 +48,21 @@
const MCFixup &Fixup,
MCValue Target,
uint64_t &FixedValue);
- void RecordX86_64Relocation(MachObjectWriter *Writer,
- const MCAssembler &Asm,
+ void RecordX86_64Relocation(MachObjectWriter *Writer, MCAssembler &Asm,
const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue);
+ const MCFragment *Fragment, const MCFixup &Fixup,
+ MCValue Target, uint64_t &FixedValue);
+
public:
X86MachObjectWriter(bool Is64Bit, uint32_t CPUType,
uint32_t CPUSubtype)
: MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype,
/*UseAggressiveSymbolFolding=*/Is64Bit) {}
- void RecordRelocation(MachObjectWriter *Writer,
- const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue) override {
+ void RecordRelocation(MachObjectWriter *Writer, MCAssembler &Asm,
+ const MCAsmLayout &Layout, const MCFragment *Fragment,
+ const MCFixup &Fixup, MCValue Target,
+ uint64_t &FixedValue) override {
if (Writer->is64Bit())
RecordX86_64Relocation(Writer, Asm, Layout, Fragment, Fixup, Target,
FixedValue);
@@ -97,13 +96,10 @@
}
}
-void X86MachObjectWriter::RecordX86_64Relocation(MachObjectWriter *Writer,
- const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue) {
+void X86MachObjectWriter::RecordX86_64Relocation(
+ 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());
unsigned IsRIPRel = isFixupKindRIPRel(Fixup.getKind());
unsigned Log2Size = getFixupKindLog2Size(Fixup.getKind());
@@ -117,6 +113,7 @@
unsigned Index = 0;
unsigned IsExtern = 0;
unsigned Type = 0;
+ const MCSymbolData *RelSymbol = nullptr;
Value = Target.getConstant();
@@ -132,7 +129,6 @@
if (Target.isAbsolute()) { // constant
// SymbolNum of 0 indicates the absolute section.
Type = MachO::X86_64_RELOC_UNSIGNED;
- Index = 0;
// FIXME: I believe this is broken, I don't think the linker can understand
// it. I think it would require a local relocation, but I'm not sure if that
@@ -193,36 +189,30 @@
Value -= Writer->getSymbolAddress(&B_SD, Layout) -
(!B_Base ? 0 : Writer->getSymbolAddress(B_Base, Layout));
- if (A_Base) {
- Index = A_Base->getIndex();
- IsExtern = 1;
- } else {
+ if (!A_Base)
Index = A_SD.getFragment()->getParent()->getOrdinal() + 1;
- IsExtern = 0;
- }
Type = MachO::X86_64_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 =
+ (Index << 0) | (IsPCRel << 24) | (Log2Size << 25) | (Type << 28);
+ Writer->addRelocation(A_Base, Fragment->getParent(), MRE);
- if (B_Base) {
- Index = B_Base->getIndex();
- IsExtern = 1;
- } else {
+ if (B_Base)
+ RelSymbol = B_Base;
+ else
Index = B_SD.getFragment()->getParent()->getOrdinal() + 1;
- IsExtern = 0;
- }
Type = MachO::X86_64_RELOC_SUBTRACTOR;
} else {
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
+ if (Symbol->isTemporary() && Value) {
+ 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);
+ RelSymbol = Asm.getAtom(&SD);
// Relocations inside debug sections always use local relocations when
// possible. This seems to be done because the debugger doesn't fully
@@ -232,23 +222,20 @@
const MCSectionMachO &Section = static_cast<const MCSectionMachO&>(
Fragment->getParent()->getSection());
if (Section.hasAttribute(MachO::S_ATTR_DEBUG))
- Base = nullptr;
+ RelSymbol = nullptr;
}
// x86_64 almost always uses external relocations, except when there is no
// symbol to use as a base address (a local symbol with no preceding
// non-local symbol).
- if (Base) {
- Index = Base->getIndex();
- IsExtern = 1;
-
+ if (RelSymbol) {
// Add the local offset, if needed.
- if (Base != &SD)
- Value += Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(Base);
+ if (RelSymbol != &SD)
+ Value +=
+ Layout.getSymbolOffset(&SD) - Layout.getSymbolOffset(RelSymbol);
} else if (Symbol->isInSection() && !Symbol->isVariable()) {
// The index is the section ordinal (1-based).
Index = SD.getFragment()->getParent()->getOrdinal() + 1;
- IsExtern = 0;
Value += Writer->getSymbolAddress(&SD, Layout);
if (IsPCRel)
@@ -347,12 +334,9 @@
// 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) |
+ (IsExtern << 27) | (Type << 28);
+ Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
}
bool X86MachObjectWriter::RecordScatteredRelocation(MachObjectWriter *Writer,
@@ -424,7 +408,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value2;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
} else {
// If the offset is more than 24-bits, it won't fit in a scattered
// relocation offset field, so we fall back to using a non-scattered
@@ -446,7 +430,7 @@
(IsPCRel << 30) |
MachO::R_SCATTERED);
MRE.r_word1 = Value;
- Writer->addRelocation(Fragment->getParent(), MRE);
+ Writer->addRelocation(nullptr, Fragment->getParent(), MRE);
return true;
}
@@ -467,7 +451,6 @@
// Get the symbol data.
const MCSymbolData *SD_A = &Asm.getSymbolData(Target.getSymA()->getSymbol());
- unsigned Index = SD_A->getIndex();
// We're only going to have a second symbol in pic mode and it'll be a
// subtraction from the picbase. For 32-bit pic the addend is the difference
@@ -490,12 +473,9 @@
// struct relocation_info (8 bytes)
MachO::any_relocation_info MRE;
MRE.r_word0 = Value;
- MRE.r_word1 = ((Index << 0) |
- (IsPCRel << 24) |
- (Log2Size << 25) |
- (1 << 27) | // r_extern
- (MachO::GENERIC_RELOC_TLV << 28)); // r_type
- Writer->addRelocation(Fragment->getParent(), MRE);
+ MRE.r_word1 =
+ (IsPCRel << 24) | (Log2Size << 25) | (MachO::GENERIC_RELOC_TLV << 28);
+ Writer->addRelocation(SD_A, Fragment->getParent(), MRE);
}
void X86MachObjectWriter::RecordX86Relocation(MachObjectWriter *Writer,
@@ -546,8 +526,8 @@
// See <reloc.h>.
uint32_t FixupOffset = Layout.getFragmentOffset(Fragment)+Fixup.getOffset();
unsigned Index = 0;
- unsigned IsExtern = 0;
unsigned Type = 0;
+ const MCSymbolData *RelSymbol = nullptr;
if (Target.isAbsolute()) { // constant
// SymbolNum of 0 indicates the absolute section.
@@ -568,8 +548,7 @@
// Check whether we need an external or internal relocation.
if (Writer->doesSymbolRequireExternRelocation(SD)) {
- IsExtern = 1;
- Index = SD->getIndex();
+ RelSymbol = SD;
// For external relocations, make sure to offset the fixup value to
// compensate for the addend of the symbol address, if it was
// undefined. This occurs with weak definitions, for example.
@@ -591,12 +570,9 @@
// 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::createX86MachObjectWriter(raw_ostream &OS,