[llvm] r232837 - Reorganize the x86 ELF relocation selection logic.
Rafael Espindola
rafael.espindola at gmail.com
Fri Mar 20 12:48:55 PDT 2015
Author: rafael
Date: Fri Mar 20 14:48:54 2015
New Revision: 232837
URL: http://llvm.org/viewvc/llvm-project?rev=232837&view=rev
Log:
Reorganize the x86 ELF relocation selection logic.
The main differences are:
* Split in 32 and 64 bit functions.
* First switch on the Modifier so that we have only one non fully covered
switch.
* Map the fixup kind first to a x86_64 (or i386) specific enum, to make
it easy to handle cases like X86::reloc_riprel_4byte_movq_load.
* Switch on IsPCRel last, which reduces code duplication.
Fixes pr22308.
Modified:
llvm/trunk/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
llvm/trunk/test/MC/ELF/relocation-386.s
llvm/trunk/test/MC/ELF/relocation.s
Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp?rev=232837&r1=232836&r2=232837&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp Fri Mar 20 14:48:54 2015
@@ -38,193 +38,215 @@ X86ELFObjectWriter::X86ELFObjectWriter(b
X86ELFObjectWriter::~X86ELFObjectWriter()
{}
-unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
- const MCFixup &Fixup,
- bool IsPCRel) const {
- // determine the type of the relocation
+enum X86_64RelType { RT64_64, RT64_32, RT64_32S, RT64_16, RT64_8 };
- MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
- if (getEMachine() == ELF::EM_X86_64) {
- if (IsPCRel) {
- switch ((unsigned)Fixup.getKind()) {
- default:
- llvm_unreachable("invalid fixup kind!");
-
- case FK_Data_8:
- return ELF::R_X86_64_PC64;
- case FK_Data_4:
- return ELF::R_X86_64_PC32;
- case FK_Data_2:
- return ELF::R_X86_64_PC16;
- case FK_Data_1:
- return ELF::R_X86_64_PC8;
- case FK_PCRel_8:
- assert(Modifier == MCSymbolRefExpr::VK_None);
- return ELF::R_X86_64_PC64;
- case X86::reloc_signed_4byte:
- case X86::reloc_riprel_4byte_movq_load:
- case X86::reloc_riprel_4byte:
- case FK_PCRel_4:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_X86_64_PC32;
- case MCSymbolRefExpr::VK_PLT:
- return ELF::R_X86_64_PLT32;
- case MCSymbolRefExpr::VK_GOTPCREL:
- return ELF::R_X86_64_GOTPCREL;
- case MCSymbolRefExpr::VK_GOTTPOFF:
- return ELF::R_X86_64_GOTTPOFF;
- case MCSymbolRefExpr::VK_TLSGD:
- return ELF::R_X86_64_TLSGD;
- case MCSymbolRefExpr::VK_TLSLD:
- return ELF::R_X86_64_TLSLD;
- }
- case FK_PCRel_2:
- assert(Modifier == MCSymbolRefExpr::VK_None);
- return ELF::R_X86_64_PC16;
- case FK_PCRel_1:
- assert(Modifier == MCSymbolRefExpr::VK_None);
- return ELF::R_X86_64_PC8;
- }
- }
- switch ((unsigned)Fixup.getKind()) {
- default:
- llvm_unreachable("invalid fixup kind!");
- case X86::reloc_global_offset_table8:
- return ELF::R_X86_64_GOTPC64;
- case X86::reloc_global_offset_table:
- return ELF::R_X86_64_GOTPC32;
- case FK_Data_8:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_X86_64_64;
- case MCSymbolRefExpr::VK_GOT:
- return ELF::R_X86_64_GOT64;
- case MCSymbolRefExpr::VK_GOTOFF:
- return ELF::R_X86_64_GOTOFF64;
- case MCSymbolRefExpr::VK_TPOFF:
- return ELF::R_X86_64_TPOFF64;
- case MCSymbolRefExpr::VK_DTPOFF:
- return ELF::R_X86_64_DTPOFF64;
- case MCSymbolRefExpr::VK_SIZE:
- return ELF::R_X86_64_SIZE64;
- }
- case X86::reloc_signed_4byte:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_X86_64_32S;
- case MCSymbolRefExpr::VK_GOT:
- return ELF::R_X86_64_GOT32;
- case MCSymbolRefExpr::VK_GOTPCREL:
- return ELF::R_X86_64_GOTPCREL;
- case MCSymbolRefExpr::VK_TPOFF:
- return ELF::R_X86_64_TPOFF32;
- case MCSymbolRefExpr::VK_DTPOFF:
- return ELF::R_X86_64_DTPOFF32;
- case MCSymbolRefExpr::VK_SIZE:
- return ELF::R_X86_64_SIZE32;
- }
- case FK_Data_4:
- return ELF::R_X86_64_32;
- case FK_Data_2:
- return ELF::R_X86_64_16;
- case FK_PCRel_1:
- case FK_Data_1:
- return ELF::R_X86_64_8;
+static X86_64RelType getType64(unsigned Kind,
+ MCSymbolRefExpr::VariantKind &Modifier,
+ bool &IsPCRel) {
+ switch (Kind) {
+ default:
+ llvm_unreachable("Unimplemented");
+ case X86::reloc_global_offset_table8:
+ Modifier = MCSymbolRefExpr::VK_GOT;
+ IsPCRel = true;
+ return RT64_64;
+ case FK_Data_8:
+ return RT64_64;
+ case X86::reloc_signed_4byte:
+ if (Modifier == MCSymbolRefExpr::VK_None && !IsPCRel)
+ return RT64_32S;
+ return RT64_32;
+ case X86::reloc_global_offset_table:
+ Modifier = MCSymbolRefExpr::VK_GOT;
+ IsPCRel = true;
+ return RT64_32;
+ case FK_Data_4:
+ case FK_PCRel_4:
+ case X86::reloc_riprel_4byte:
+ case X86::reloc_riprel_4byte_movq_load:
+ return RT64_32;
+ case FK_Data_2:
+ return RT64_16;
+ case FK_PCRel_1:
+ case FK_Data_1:
+ return RT64_8;
+ }
+}
+
+unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier,
+ X86_64RelType Type, bool IsPCRel) {
+ switch (Modifier) {
+ default:
+ llvm_unreachable("Unimplemented");
+ case MCSymbolRefExpr::VK_None:
+ switch (Type) {
+ case RT64_64:
+ return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
+ case RT64_32:
+ return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
+ case RT64_32S:
+ return ELF::R_X86_64_32S;
+ case RT64_16:
+ return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16;
+ case RT64_8:
+ return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
}
+ case MCSymbolRefExpr::VK_GOT:
+ switch (Type) {
+ case RT64_64:
+ return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64;
+ case RT64_32:
+ return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32;
+ case RT64_32S:
+ case RT64_16:
+ case RT64_8:
+ llvm_unreachable("Unimplemented");
+ }
+ case MCSymbolRefExpr::VK_GOTOFF:
+ assert(Type == RT64_64);
+ assert(!IsPCRel);
+ return ELF::R_X86_64_GOTOFF64;
+ case MCSymbolRefExpr::VK_TPOFF:
+ assert(!IsPCRel);
+ switch (Type) {
+ case RT64_64:
+ return ELF::R_X86_64_TPOFF64;
+ case RT64_32:
+ return ELF::R_X86_64_TPOFF32;
+ case RT64_32S:
+ case RT64_16:
+ case RT64_8:
+ llvm_unreachable("Unimplemented");
+ }
+ case MCSymbolRefExpr::VK_DTPOFF:
+ assert(!IsPCRel);
+ switch (Type) {
+ case RT64_64:
+ return ELF::R_X86_64_DTPOFF64;
+ case RT64_32:
+ return ELF::R_X86_64_DTPOFF32;
+ case RT64_32S:
+ case RT64_16:
+ case RT64_8:
+ llvm_unreachable("Unimplemented");
+ }
+ case MCSymbolRefExpr::VK_SIZE:
+ assert(!IsPCRel);
+ switch (Type) {
+ case RT64_64:
+ return ELF::R_X86_64_SIZE64;
+ case RT64_32:
+ return ELF::R_X86_64_SIZE32;
+ case RT64_32S:
+ case RT64_16:
+ case RT64_8:
+ llvm_unreachable("Unimplemented");
+ }
+ case MCSymbolRefExpr::VK_TLSGD:
+ assert(Type == RT64_32);
+ return ELF::R_X86_64_TLSGD;
+ case MCSymbolRefExpr::VK_GOTTPOFF:
+ assert(Type == RT64_32);
+ return ELF::R_X86_64_GOTTPOFF;
+ case MCSymbolRefExpr::VK_TLSLD:
+ assert(Type == RT64_32);
+ return ELF::R_X86_64_TLSLD;
+ case MCSymbolRefExpr::VK_PLT:
+ assert(Type == RT64_32);
+ return ELF::R_X86_64_PLT32;
+ case MCSymbolRefExpr::VK_GOTPCREL:
+ assert(Type == RT64_32);
+ return ELF::R_X86_64_GOTPCREL;
}
- assert(getEMachine() == ELF::EM_386 && "Unsupported ELF machine type.");
- if (IsPCRel) {
- switch ((unsigned)Fixup.getKind()) {
- default:
- llvm_unreachable("invalid fixup kind!");
-
- case X86::reloc_global_offset_table:
- return ELF::R_386_GOTPC;
- case FK_PCRel_1:
- case FK_Data_1:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_386_PC8;
- }
- case FK_PCRel_2:
- case FK_Data_2:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_386_PC16;
- }
- case X86::reloc_riprel_4byte:
- case X86::reloc_signed_4byte:
- case FK_PCRel_4:
- case FK_Data_4:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_386_PC32;
- case MCSymbolRefExpr::VK_PLT:
- return ELF::R_386_PLT32;
- }
- }
- } else {
- switch ((unsigned)Fixup.getKind()) {
- default:
- llvm_unreachable("invalid fixup kind!");
- case X86::reloc_global_offset_table:
- return ELF::R_386_GOTPC;
-
- // FIXME: Should we avoid selecting reloc_signed_4byte in 32 bit mode
- // instead?
- case X86::reloc_signed_4byte:
- case FK_PCRel_4:
- case FK_Data_4:
- switch (Modifier) {
- default:
- llvm_unreachable("Unimplemented");
- case MCSymbolRefExpr::VK_None:
- return ELF::R_386_32;
- case MCSymbolRefExpr::VK_GOT:
- return ELF::R_386_GOT32;
- case MCSymbolRefExpr::VK_PLT:
- return ELF::R_386_PLT32;
- case MCSymbolRefExpr::VK_GOTOFF:
- return ELF::R_386_GOTOFF;
- case MCSymbolRefExpr::VK_TLSGD:
- return ELF::R_386_TLS_GD;
- case MCSymbolRefExpr::VK_TPOFF:
- return ELF::R_386_TLS_LE_32;
- case MCSymbolRefExpr::VK_INDNTPOFF:
- return ELF::R_386_TLS_IE;
- case MCSymbolRefExpr::VK_NTPOFF:
- return ELF::R_386_TLS_LE;
- case MCSymbolRefExpr::VK_GOTNTPOFF:
- return ELF::R_386_TLS_GOTIE;
- case MCSymbolRefExpr::VK_TLSLDM:
- return ELF::R_386_TLS_LDM;
- case MCSymbolRefExpr::VK_DTPOFF:
- return ELF::R_386_TLS_LDO_32;
- case MCSymbolRefExpr::VK_GOTTPOFF:
- return ELF::R_386_TLS_IE_32;
- }
- case FK_Data_2:
- return ELF::R_386_16;
- case FK_PCRel_1:
- case FK_Data_1:
- return ELF::R_386_8;
+}
+
+enum X86_32RelType { RT32_32, RT32_16, RT32_8 };
+
+static X86_32RelType getType32(X86_64RelType T) {
+ switch (T) {
+ case RT64_64:
+ llvm_unreachable("Unimplemented");
+ case RT64_32:
+ case RT64_32S:
+ return RT32_32;
+ case RT64_16:
+ return RT32_16;
+ case RT64_8:
+ return RT32_8;
+ }
+}
+
+unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier,
+ X86_32RelType Type, bool IsPCRel) {
+ switch (Modifier) {
+ default:
+ llvm_unreachable("Unimplemented");
+ case MCSymbolRefExpr::VK_None:
+ switch (Type) {
+ case RT32_32:
+ return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32;
+ case RT32_16:
+ return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16;
+ case RT32_8:
+ return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
}
+ case MCSymbolRefExpr::VK_GOT:
+ assert(Type == RT32_32);
+ return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32;
+ case MCSymbolRefExpr::VK_GOTOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_GOTOFF;
+ case MCSymbolRefExpr::VK_TPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_LE_32;
+ case MCSymbolRefExpr::VK_DTPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_LDO_32;
+ case MCSymbolRefExpr::VK_TLSGD:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_GD;
+ case MCSymbolRefExpr::VK_GOTTPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_IE_32;
+ case MCSymbolRefExpr::VK_PLT:
+ assert(Type == RT32_32);
+ return ELF::R_386_PLT32;
+ case MCSymbolRefExpr::VK_INDNTPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_IE;
+ case MCSymbolRefExpr::VK_NTPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_LE;
+ case MCSymbolRefExpr::VK_GOTNTPOFF:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_GOTIE;
+ case MCSymbolRefExpr::VK_TLSLDM:
+ assert(Type == RT32_32);
+ assert(!IsPCRel);
+ return ELF::R_386_TLS_LDM;
}
}
+unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
+ X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel);
+ if (getEMachine() == ELF::EM_X86_64)
+ return getRelocType64(Modifier, Type, IsPCRel);
+
+ assert(getEMachine() == ELF::EM_386 && "Unsupported ELF machine type.");
+ return getRelocType32(Modifier, getType32(Type), IsPCRel);
+}
+
MCObjectWriter *llvm::createX86ELFObjectWriter(raw_ostream &OS,
bool IsELF64,
uint8_t OSABI,
Modified: llvm/trunk/test/MC/ELF/relocation-386.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/relocation-386.s?rev=232837&r1=232836&r2=232837&view=diff
==============================================================================
--- llvm/trunk/test/MC/ELF/relocation-386.s (original)
+++ llvm/trunk/test/MC/ELF/relocation-386.s Fri Mar 20 14:48:54 2015
@@ -66,6 +66,8 @@
// Relocation 29 (zed at PLT) is of type R_386_PLT32 and uses the symbol
// CHECK-NEXT: 0xA9 R_386_PLT32 zed 0x0
// CHECK-NEXT: 0xAF R_386_PC32 tr_start 0x0
+// CHECK-NEXT: 0xB3 R_386_16 foo 0x0
+// CHECK-NEXT: 0xB5 R_386_8 foo 0x0
// CHECK-NEXT: }
// CHECK-NEXT: ]
@@ -137,6 +139,9 @@ bar2:
.code64
jmpq *tr_start(%rip)
+ .word foo
+ .byte foo
+
.section zedsec,"awT", at progbits
zed:
.long 0
Modified: llvm/trunk/test/MC/ELF/relocation.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ELF/relocation.s?rev=232837&r1=232836&r2=232837&view=diff
==============================================================================
--- llvm/trunk/test/MC/ELF/relocation.s (original)
+++ llvm/trunk/test/MC/ELF/relocation.s Fri Mar 20 14:48:54 2015
@@ -41,6 +41,8 @@ bar:
movl blah at SIZE + 32, %eax # R_X86_64_SIZE32
movl blah at SIZE - 32, %eax # R_X86_64_SIZE32
+ .long foo at gotpcrel
+ .long foo at plt
// CHECK: Section {
// CHECK: Name: .rela.text
// CHECK: Relocations [
@@ -75,6 +77,8 @@ bar:
// CHECK-NEXT: 0xC6 R_X86_64_SIZE32 blah 0x0
// CHECK-NEXT: 0xCD R_X86_64_SIZE32 blah 0x20
// CHECK-NEXT: 0xD4 R_X86_64_SIZE32 blah 0xFFFFFFFFFFFFFFE0
+// CHECK-NEXT: 0xD8 R_X86_64_GOTPCREL foo 0x0
+// CHECK-NEXT: 0xDC R_X86_64_PLT32 foo 0x0
// CHECK-NEXT: ]
// CHECK-NEXT: }
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