1 //===-- AArch64MCExpr.cpp - AArch64 specific MC expression classes --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the implementation of the assembly expression modifiers
10 // accepted by the AArch64 architecture (e.g. ":lo12:", ":gottprel_g1:", ...).
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "AArch64MCExpr.h"
15 #include "llvm/BinaryFormat/ELF.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCStreamer.h"
18 #include "llvm/MC/MCSymbolELF.h"
19 #include "llvm/MC/MCValue.h"
20 #include "llvm/Support/Casting.h"
21 #include "llvm/Support/ErrorHandling.h"
22
23 using namespace llvm;
24
25 #define DEBUG_TYPE "aarch64symbolrefexpr"
26
create(const MCExpr * Expr,VariantKind Kind,MCContext & Ctx)27 const AArch64MCExpr *AArch64MCExpr::create(const MCExpr *Expr, VariantKind Kind,
28 MCContext &Ctx) {
29 return new (Ctx) AArch64MCExpr(Expr, Kind);
30 }
31
getVariantKindName() const32 StringRef AArch64MCExpr::getVariantKindName() const {
33 switch (static_cast<uint32_t>(getKind())) {
34 case VK_CALL: return "";
35 case VK_LO12: return ":lo12:";
36 case VK_ABS_G3: return ":abs_g3:";
37 case VK_ABS_G2: return ":abs_g2:";
38 case VK_ABS_G2_S: return ":abs_g2_s:";
39 case VK_ABS_G2_NC: return ":abs_g2_nc:";
40 case VK_ABS_G1: return ":abs_g1:";
41 case VK_ABS_G1_S: return ":abs_g1_s:";
42 case VK_ABS_G1_NC: return ":abs_g1_nc:";
43 case VK_ABS_G0: return ":abs_g0:";
44 case VK_ABS_G0_S: return ":abs_g0_s:";
45 case VK_ABS_G0_NC: return ":abs_g0_nc:";
46 case VK_PREL_G3: return ":prel_g3:";
47 case VK_PREL_G2: return ":prel_g2:";
48 case VK_PREL_G2_NC: return ":prel_g2_nc:";
49 case VK_PREL_G1: return ":prel_g1:";
50 case VK_PREL_G1_NC: return ":prel_g1_nc:";
51 case VK_PREL_G0: return ":prel_g0:";
52 case VK_PREL_G0_NC: return ":prel_g0_nc:";
53 case VK_DTPREL_G2: return ":dtprel_g2:";
54 case VK_DTPREL_G1: return ":dtprel_g1:";
55 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:";
56 case VK_DTPREL_G0: return ":dtprel_g0:";
57 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:";
58 case VK_DTPREL_HI12: return ":dtprel_hi12:";
59 case VK_DTPREL_LO12: return ":dtprel_lo12:";
60 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:";
61 case VK_TPREL_G2: return ":tprel_g2:";
62 case VK_TPREL_G1: return ":tprel_g1:";
63 case VK_TPREL_G1_NC: return ":tprel_g1_nc:";
64 case VK_TPREL_G0: return ":tprel_g0:";
65 case VK_TPREL_G0_NC: return ":tprel_g0_nc:";
66 case VK_TPREL_HI12: return ":tprel_hi12:";
67 case VK_TPREL_LO12: return ":tprel_lo12:";
68 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:";
69 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:";
70 case VK_ABS_PAGE: return "";
71 case VK_ABS_PAGE_NC: return ":pg_hi21_nc:";
72 case VK_GOT: return ":got:";
73 case VK_GOT_PAGE: return ":got:";
74 case VK_GOT_PAGE_LO15: return ":gotpage_lo15:";
75 case VK_GOT_LO12: return ":got_lo12:";
76 case VK_GOTTPREL: return ":gottprel:";
77 case VK_GOTTPREL_PAGE: return ":gottprel:";
78 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:";
79 case VK_GOTTPREL_G1: return ":gottprel_g1:";
80 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:";
81 case VK_TLSDESC: return "";
82 case VK_TLSDESC_PAGE: return ":tlsdesc:";
83 case VK_SECREL_LO12: return ":secrel_lo12:";
84 case VK_SECREL_HI12: return ":secrel_hi12:";
85 default:
86 llvm_unreachable("Invalid ELF symbol kind");
87 }
88 }
89
printImpl(raw_ostream & OS,const MCAsmInfo * MAI) const90 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
91 OS << getVariantKindName();
92 Expr->print(OS, MAI);
93 }
94
visitUsedExpr(MCStreamer & Streamer) const95 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
96 Streamer.visitUsedExpr(*getSubExpr());
97 }
98
findAssociatedFragment() const99 MCFragment *AArch64MCExpr::findAssociatedFragment() const {
100 llvm_unreachable("FIXME: what goes here?");
101 }
102
evaluateAsRelocatableImpl(MCValue & Res,const MCAssembler * Asm,const MCFixup * Fixup) const103 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res,
104 const MCAssembler *Asm,
105 const MCFixup *Fixup) const {
106 if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup))
107 return false;
108
109 Res =
110 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
111
112 return true;
113 }
114
fixELFSymbolsInTLSFixupsImpl(const MCExpr * Expr,MCAssembler & Asm)115 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
116 switch (Expr->getKind()) {
117 case MCExpr::Target:
118 llvm_unreachable("Can't handle nested target expression");
119 break;
120 case MCExpr::Constant:
121 break;
122
123 case MCExpr::Binary: {
124 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
125 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
126 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
127 break;
128 }
129
130 case MCExpr::SymbolRef: {
131 // We're known to be under a TLS fixup, so any symbol should be
132 // modified. There should be only one.
133 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
134 cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS);
135 break;
136 }
137
138 case MCExpr::Unary:
139 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
140 break;
141 }
142 }
143
fixELFSymbolsInTLSFixups(MCAssembler & Asm) const144 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
145 switch (getSymbolLoc(Kind)) {
146 default:
147 return;
148 case VK_DTPREL:
149 case VK_GOTTPREL:
150 case VK_TPREL:
151 case VK_TLSDESC:
152 break;
153 }
154
155 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
156 }
157
create(const MCExpr * Expr,uint16_t Discriminator,AArch64PACKey::ID Key,bool HasAddressDiversity,MCContext & Ctx)158 const AArch64AuthMCExpr *AArch64AuthMCExpr::create(const MCExpr *Expr,
159 uint16_t Discriminator,
160 AArch64PACKey::ID Key,
161 bool HasAddressDiversity,
162 MCContext &Ctx) {
163 return new (Ctx)
164 AArch64AuthMCExpr(Expr, Discriminator, Key, HasAddressDiversity);
165 }
166
printImpl(raw_ostream & OS,const MCAsmInfo * MAI) const167 void AArch64AuthMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
168 bool WrapSubExprInParens = !isa<MCSymbolRefExpr>(getSubExpr());
169 if (WrapSubExprInParens)
170 OS << '(';
171 getSubExpr()->print(OS, MAI);
172 if (WrapSubExprInParens)
173 OS << ')';
174
175 OS << "@AUTH(" << AArch64PACKeyIDToString(Key) << ',' << Discriminator;
176 if (hasAddressDiversity())
177 OS << ",addr";
178 OS << ')';
179 }
180
visitUsedExpr(MCStreamer & Streamer) const181 void AArch64AuthMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
182 Streamer.visitUsedExpr(*getSubExpr());
183 }
184
findAssociatedFragment() const185 MCFragment *AArch64AuthMCExpr::findAssociatedFragment() const {
186 llvm_unreachable("FIXME: what goes here?");
187 }
188
evaluateAsRelocatableImpl(MCValue & Res,const MCAssembler * Asm,const MCFixup * Fixup) const189 bool AArch64AuthMCExpr::evaluateAsRelocatableImpl(MCValue &Res,
190 const MCAssembler *Asm,
191 const MCFixup *Fixup) const {
192 if (!getSubExpr()->evaluateAsRelocatable(Res, Asm, Fixup))
193 return false;
194
195 if (Res.getSymB())
196 report_fatal_error("Auth relocation can't reference two symbols");
197
198 Res = MCValue::get(Res.getSymA(), nullptr, Res.getConstant(), getKind());
199 return true;
200 }
201