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/ErrorHandling.h"
21
22 using namespace llvm;
23
24 #define DEBUG_TYPE "aarch64symbolrefexpr"
25
create(const MCExpr * Expr,VariantKind Kind,MCContext & Ctx)26 const AArch64MCExpr *AArch64MCExpr::create(const MCExpr *Expr, VariantKind Kind,
27 MCContext &Ctx) {
28 return new (Ctx) AArch64MCExpr(Expr, Kind);
29 }
30
getVariantKindName() const31 StringRef AArch64MCExpr::getVariantKindName() const {
32 switch (static_cast<uint32_t>(getKind())) {
33 case VK_CALL: return "";
34 case VK_LO12: return ":lo12:";
35 case VK_ABS_G3: return ":abs_g3:";
36 case VK_ABS_G2: return ":abs_g2:";
37 case VK_ABS_G2_S: return ":abs_g2_s:";
38 case VK_ABS_G2_NC: return ":abs_g2_nc:";
39 case VK_ABS_G1: return ":abs_g1:";
40 case VK_ABS_G1_S: return ":abs_g1_s:";
41 case VK_ABS_G1_NC: return ":abs_g1_nc:";
42 case VK_ABS_G0: return ":abs_g0:";
43 case VK_ABS_G0_S: return ":abs_g0_s:";
44 case VK_ABS_G0_NC: return ":abs_g0_nc:";
45 case VK_PREL_G3: return ":prel_g3:";
46 case VK_PREL_G2: return ":prel_g2:";
47 case VK_PREL_G2_NC: return ":prel_g2_nc:";
48 case VK_PREL_G1: return ":prel_g1:";
49 case VK_PREL_G1_NC: return ":prel_g1_nc:";
50 case VK_PREL_G0: return ":prel_g0:";
51 case VK_PREL_G0_NC: return ":prel_g0_nc:";
52 case VK_DTPREL_G2: return ":dtprel_g2:";
53 case VK_DTPREL_G1: return ":dtprel_g1:";
54 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:";
55 case VK_DTPREL_G0: return ":dtprel_g0:";
56 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:";
57 case VK_DTPREL_HI12: return ":dtprel_hi12:";
58 case VK_DTPREL_LO12: return ":dtprel_lo12:";
59 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:";
60 case VK_TPREL_G2: return ":tprel_g2:";
61 case VK_TPREL_G1: return ":tprel_g1:";
62 case VK_TPREL_G1_NC: return ":tprel_g1_nc:";
63 case VK_TPREL_G0: return ":tprel_g0:";
64 case VK_TPREL_G0_NC: return ":tprel_g0_nc:";
65 case VK_TPREL_HI12: return ":tprel_hi12:";
66 case VK_TPREL_LO12: return ":tprel_lo12:";
67 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:";
68 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:";
69 case VK_ABS_PAGE: return "";
70 case VK_ABS_PAGE_NC: return ":pg_hi21_nc:";
71 case VK_GOT: return ":got:";
72 case VK_GOT_PAGE: return ":got:";
73 case VK_GOT_LO12: return ":got_lo12:";
74 case VK_GOTTPREL: return ":gottprel:";
75 case VK_GOTTPREL_PAGE: return ":gottprel:";
76 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:";
77 case VK_GOTTPREL_G1: return ":gottprel_g1:";
78 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:";
79 case VK_TLSDESC: return "";
80 case VK_TLSDESC_PAGE: return ":tlsdesc:";
81 case VK_SECREL_LO12: return ":secrel_lo12:";
82 case VK_SECREL_HI12: return ":secrel_hi12:";
83 default:
84 llvm_unreachable("Invalid ELF symbol kind");
85 }
86 }
87
printImpl(raw_ostream & OS,const MCAsmInfo * MAI) const88 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
89 OS << getVariantKindName();
90 Expr->print(OS, MAI);
91 }
92
visitUsedExpr(MCStreamer & Streamer) const93 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
94 Streamer.visitUsedExpr(*getSubExpr());
95 }
96
findAssociatedFragment() const97 MCFragment *AArch64MCExpr::findAssociatedFragment() const {
98 llvm_unreachable("FIXME: what goes here?");
99 }
100
evaluateAsRelocatableImpl(MCValue & Res,const MCAsmLayout * Layout,const MCFixup * Fixup) const101 bool AArch64MCExpr::evaluateAsRelocatableImpl(MCValue &Res,
102 const MCAsmLayout *Layout,
103 const MCFixup *Fixup) const {
104 if (!getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup))
105 return false;
106
107 Res =
108 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
109
110 return true;
111 }
112
fixELFSymbolsInTLSFixupsImpl(const MCExpr * Expr,MCAssembler & Asm)113 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
114 switch (Expr->getKind()) {
115 case MCExpr::Target:
116 llvm_unreachable("Can't handle nested target expression");
117 break;
118 case MCExpr::Constant:
119 break;
120
121 case MCExpr::Binary: {
122 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
123 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
124 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
125 break;
126 }
127
128 case MCExpr::SymbolRef: {
129 // We're known to be under a TLS fixup, so any symbol should be
130 // modified. There should be only one.
131 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
132 cast<MCSymbolELF>(SymRef.getSymbol()).setType(ELF::STT_TLS);
133 break;
134 }
135
136 case MCExpr::Unary:
137 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
138 break;
139 }
140 }
141
fixELFSymbolsInTLSFixups(MCAssembler & Asm) const142 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
143 switch (getSymbolLoc(Kind)) {
144 default:
145 return;
146 case VK_DTPREL:
147 case VK_GOTTPREL:
148 case VK_TPREL:
149 case VK_TLSDESC:
150 break;
151 }
152
153 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
154 }
155