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_None:
163 Type = ELF::R_ARM_ABS16;
169 default: llvm_unreachable("Unsupported Modifier");
170 case MCSymbolRefExpr::VK_ARM_NONE:
171 Type = ELF::R_ARM_NONE;
173 case MCSymbolRefExpr::VK_GOT:
174 Type = ELF::R_ARM_GOT_BREL;
176 case MCSymbolRefExpr::VK_TLSGD:
177 Type = ELF::R_ARM_TLS_GD32;
179 case MCSymbolRefExpr::VK_TPOFF:
180 Type = ELF::R_ARM_TLS_LE32;
182 case MCSymbolRefExpr::VK_GOTTPOFF:
183 Type = ELF::R_ARM_TLS_IE32;
185 case MCSymbolRefExpr::VK_None:
186 Type = ELF::R_ARM_ABS32;
188 case MCSymbolRefExpr::VK_GOTOFF:
189 Type = ELF::R_ARM_GOTOFF32;
191 case MCSymbolRefExpr::VK_GOTPCREL:
192 Type = ELF::R_ARM_GOT_PREL;
194 case MCSymbolRefExpr::VK_ARM_TARGET1:
195 Type = ELF::R_ARM_TARGET1;
197 case MCSymbolRefExpr::VK_ARM_TARGET2:
198 Type = ELF::R_ARM_TARGET2;
200 case MCSymbolRefExpr::VK_ARM_PREL31:
201 Type = ELF::R_ARM_PREL31;
203 case MCSymbolRefExpr::VK_ARM_SBREL:
204 Type = ELF::R_ARM_SBREL32;
206 case MCSymbolRefExpr::VK_ARM_TLSLDO:
207 Type = ELF::R_ARM_TLS_LDO32;
209 case MCSymbolRefExpr::VK_ARM_TLSCALL:
210 Type = ELF::R_ARM_TLS_CALL;
212 case MCSymbolRefExpr::VK_ARM_TLSDESC:
213 Type = ELF::R_ARM_TLS_GOTDESC;
215 case MCSymbolRefExpr::VK_ARM_TLSDESCSEQ:
216 Type = ELF::R_ARM_TLS_DESCSEQ;
220 case ARM::fixup_arm_ldst_pcrel_12:
221 case ARM::fixup_arm_pcrel_10:
222 case ARM::fixup_arm_adr_pcrel_12:
223 case ARM::fixup_arm_thumb_bl:
224 case ARM::fixup_arm_thumb_cb:
225 case ARM::fixup_arm_thumb_cp:
226 case ARM::fixup_arm_thumb_br:
227 llvm_unreachable("Unimplemented");
228 case ARM::fixup_arm_condbranch:
229 case ARM::fixup_arm_uncondbranch:
230 Type = ELF::R_ARM_JUMP24;
232 case ARM::fixup_arm_movt_hi16:
233 Type = ELF::R_ARM_MOVT_ABS;
235 case ARM::fixup_arm_movw_lo16:
236 Type = ELF::R_ARM_MOVW_ABS_NC;
238 case ARM::fixup_t2_movt_hi16:
239 Type = ELF::R_ARM_THM_MOVT_ABS;
241 case ARM::fixup_t2_movw_lo16:
242 Type = ELF::R_ARM_THM_MOVW_ABS_NC;
250 MCObjectWriter *llvm::createARMELFObjectWriter(raw_ostream &OS,
252 bool IsLittleEndian) {
253 MCELFObjectTargetWriter *MOTW = new ARMELFObjectWriter(OSABI);
254 return createELFObjectWriter(MOTW, OS, IsLittleEndian);