1 //===-- ARMELFObjectWriter.cpp - ARM ELF Writer ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "MCTargetDesc/ARMMCTargetDesc.h"
11 #include "MCTargetDesc/ARMFixupKinds.h"
12 #include "llvm/ADT/Statistic.h"
13 #include "llvm/ADT/StringSwitch.h"
14 #include "llvm/MC/MCELFObjectWriter.h"
15 #include "llvm/MC/MCExpr.h"
16 #include "llvm/MC/MCSectionELF.h"
17 #include "llvm/MC/MCValue.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
25 class ARMELFObjectWriter : public MCELFObjectTargetWriter {
26 enum { DefaultEABIVersion = 0x05000000U };
27 unsigned GetRelocTypeInner(const MCValue &Target,
33 ARMELFObjectWriter(uint8_t OSABI);
35 virtual ~ARMELFObjectWriter();
37 unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
38 bool IsPCRel) const override;
40 bool needsRelocateWithSymbol(const MCSymbolData &SD,
41 unsigned Type) const override;
45 ARMELFObjectWriter::ARMELFObjectWriter(uint8_t OSABI)
46 : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI,
48 /*HasRelocationAddend*/ false) {}
50 ARMELFObjectWriter::~ARMELFObjectWriter() {}
52 bool ARMELFObjectWriter::needsRelocateWithSymbol(const MCSymbolData &SD,
53 unsigned Type) const {
54 // FIXME: This is extremely conservative. This really needs to use a
55 // whitelist with a clear explanation for why each realocation needs to
56 // point to the symbol, not to the section.
61 case ELF::R_ARM_PREL31:
62 case ELF::R_ARM_ABS32:
67 // Need to examine the Fixup when determining whether to
68 // emit the relocation as an explicit symbol or as a section relative
70 unsigned ARMELFObjectWriter::GetRelocType(const MCValue &Target,
73 return GetRelocTypeInner(Target, Fixup, IsPCRel);
76 unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
79 MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
83 switch ((unsigned)Fixup.getKind()) {
84 default: llvm_unreachable("Unimplemented");
87 default: llvm_unreachable("Unsupported Modifier");
88 case MCSymbolRefExpr::VK_None:
89 Type = ELF::R_ARM_REL32;
91 case MCSymbolRefExpr::VK_TLSGD:
92 llvm_unreachable("unimplemented");
93 case MCSymbolRefExpr::VK_GOTTPOFF:
94 Type = ELF::R_ARM_TLS_IE32;
96 case MCSymbolRefExpr::VK_GOTPCREL:
97 Type = ELF::R_ARM_GOT_PREL;
101 case ARM::fixup_arm_blx:
102 case ARM::fixup_arm_uncondbl:
104 case MCSymbolRefExpr::VK_PLT:
105 Type = ELF::R_ARM_CALL;
107 case MCSymbolRefExpr::VK_ARM_TLSCALL:
108 Type = ELF::R_ARM_TLS_CALL;
111 Type = ELF::R_ARM_CALL;
115 case ARM::fixup_arm_condbl:
116 case ARM::fixup_arm_condbranch:
117 case ARM::fixup_arm_uncondbranch:
118 Type = ELF::R_ARM_JUMP24;
120 case ARM::fixup_t2_condbranch:
121 case ARM::fixup_t2_uncondbranch:
122 Type = ELF::R_ARM_THM_JUMP24;
124 case ARM::fixup_arm_movt_hi16:
125 Type = ELF::R_ARM_MOVT_PREL;
127 case ARM::fixup_arm_movw_lo16:
128 Type = ELF::R_ARM_MOVW_PREL_NC;
130 case ARM::fixup_t2_movt_hi16:
131 Type = ELF::R_ARM_THM_MOVT_PREL;
133 case ARM::fixup_t2_movw_lo16:
134 Type = ELF::R_ARM_THM_MOVW_PREL_NC;
136 case ARM::fixup_arm_thumb_bl:
137 case ARM::fixup_arm_thumb_blx:
139 case MCSymbolRefExpr::VK_ARM_TLSCALL:
140 Type = ELF::R_ARM_THM_TLS_CALL;
143 Type = ELF::R_ARM_THM_CALL;
149 switch ((unsigned)Fixup.getKind()) {
150 default: llvm_unreachable("invalid fixup kind!");
153 default: llvm_unreachable("unsupported Modifier");
154 case MCSymbolRefExpr::VK_None:
155 Type = ELF::R_ARM_ABS8;
161 default: llvm_unreachable("Unsupported Modifier");
162 case MCSymbolRefExpr::VK_ARM_NONE:
163 Type = ELF::R_ARM_NONE;
165 case MCSymbolRefExpr::VK_GOT:
166 Type = ELF::R_ARM_GOT_BREL;
168 case MCSymbolRefExpr::VK_TLSGD:
169 Type = ELF::R_ARM_TLS_GD32;
171 case MCSymbolRefExpr::VK_TPOFF:
172 Type = ELF::R_ARM_TLS_LE32;
174 case MCSymbolRefExpr::VK_GOTTPOFF:
175 Type = ELF::R_ARM_TLS_IE32;
177 case MCSymbolRefExpr::VK_None:
178 Type = ELF::R_ARM_ABS32;
180 case MCSymbolRefExpr::VK_GOTOFF:
181 Type = ELF::R_ARM_GOTOFF32;
183 case MCSymbolRefExpr::VK_GOTPCREL:
184 Type = ELF::R_ARM_GOT_PREL;
186 case MCSymbolRefExpr::VK_ARM_TARGET1:
187 Type = ELF::R_ARM_TARGET1;
189 case MCSymbolRefExpr::VK_ARM_TARGET2:
190 Type = ELF::R_ARM_TARGET2;
192 case MCSymbolRefExpr::VK_ARM_PREL31:
193 Type = ELF::R_ARM_PREL31;
195 case MCSymbolRefExpr::VK_ARM_TLSLDO:
196 Type = ELF::R_ARM_TLS_LDO32;
198 case MCSymbolRefExpr::VK_ARM_TLSCALL:
199 Type = ELF::R_ARM_TLS_CALL;
201 case MCSymbolRefExpr::VK_ARM_TLSDESC:
202 Type = ELF::R_ARM_TLS_GOTDESC;
204 case MCSymbolRefExpr::VK_ARM_TLSDESCSEQ:
205 Type = ELF::R_ARM_TLS_DESCSEQ;
209 case ARM::fixup_arm_ldst_pcrel_12:
210 case ARM::fixup_arm_pcrel_10:
211 case ARM::fixup_arm_adr_pcrel_12:
212 case ARM::fixup_arm_thumb_bl:
213 case ARM::fixup_arm_thumb_cb:
214 case ARM::fixup_arm_thumb_cp:
215 case ARM::fixup_arm_thumb_br:
216 llvm_unreachable("Unimplemented");
217 case ARM::fixup_arm_condbranch:
218 case ARM::fixup_arm_uncondbranch:
219 Type = ELF::R_ARM_JUMP24;
221 case ARM::fixup_arm_movt_hi16:
222 Type = ELF::R_ARM_MOVT_ABS;
224 case ARM::fixup_arm_movw_lo16:
225 Type = ELF::R_ARM_MOVW_ABS_NC;
227 case ARM::fixup_t2_movt_hi16:
228 Type = ELF::R_ARM_THM_MOVT_ABS;
230 case ARM::fixup_t2_movw_lo16:
231 Type = ELF::R_ARM_THM_MOVW_ABS_NC;
239 MCObjectWriter *llvm::createARMELFObjectWriter(raw_ostream &OS,
241 bool IsLittleEndian) {
242 MCELFObjectTargetWriter *MOTW = new ARMELFObjectWriter(OSABI);
243 return createELFObjectWriter(MOTW, OS, IsLittleEndian);