1 //===-- AArch64MCExpr.cpp - AArch64 specific MC expression classes --------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the implementation of the assembly expression modifiers
11 // accepted by the AArch64 architecture (e.g. ":lo12:", ":gottprel_g1:", ...).
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "AArch64MCExpr.h"
16 #include "llvm/MC/MCAssembler.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCELF.h"
19 #include "llvm/MC/MCStreamer.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/Object/ELF.h"
23 #include "llvm/Support/ErrorHandling.h"
24
25 using namespace llvm;
26
27 #define DEBUG_TYPE "aarch64symbolrefexpr"
28
Create(const MCExpr * Expr,VariantKind Kind,MCContext & Ctx)29 const AArch64MCExpr *AArch64MCExpr::Create(const MCExpr *Expr, VariantKind Kind,
30 MCContext &Ctx) {
31 return new (Ctx) AArch64MCExpr(Expr, Kind);
32 }
33
getVariantKindName() const34 StringRef AArch64MCExpr::getVariantKindName() const {
35 switch (static_cast<uint32_t>(getKind())) {
36 case VK_CALL: return "";
37 case VK_LO12: return ":lo12:";
38 case VK_ABS_G3: return ":abs_g3:";
39 case VK_ABS_G2: return ":abs_g2:";
40 case VK_ABS_G2_S: return ":abs_g2_s:";
41 case VK_ABS_G2_NC: return ":abs_g2_nc:";
42 case VK_ABS_G1: return ":abs_g1:";
43 case VK_ABS_G1_S: return ":abs_g1_s:";
44 case VK_ABS_G1_NC: return ":abs_g1_nc:";
45 case VK_ABS_G0: return ":abs_g0:";
46 case VK_ABS_G0_S: return ":abs_g0_s:";
47 case VK_ABS_G0_NC: return ":abs_g0_nc:";
48 case VK_DTPREL_G2: return ":dtprel_g2:";
49 case VK_DTPREL_G1: return ":dtprel_g1:";
50 case VK_DTPREL_G1_NC: return ":dtprel_g1_nc:";
51 case VK_DTPREL_G0: return ":dtprel_g0:";
52 case VK_DTPREL_G0_NC: return ":dtprel_g0_nc:";
53 case VK_DTPREL_HI12: return ":dtprel_hi12:";
54 case VK_DTPREL_LO12: return ":dtprel_lo12:";
55 case VK_DTPREL_LO12_NC: return ":dtprel_lo12_nc:";
56 case VK_TPREL_G2: return ":tprel_g2:";
57 case VK_TPREL_G1: return ":tprel_g1:";
58 case VK_TPREL_G1_NC: return ":tprel_g1_nc:";
59 case VK_TPREL_G0: return ":tprel_g0:";
60 case VK_TPREL_G0_NC: return ":tprel_g0_nc:";
61 case VK_TPREL_HI12: return ":tprel_hi12:";
62 case VK_TPREL_LO12: return ":tprel_lo12:";
63 case VK_TPREL_LO12_NC: return ":tprel_lo12_nc:";
64 case VK_TLSDESC_LO12: return ":tlsdesc_lo12:";
65 case VK_ABS_PAGE: return "";
66 case VK_GOT_PAGE: return ":got:";
67 case VK_GOT_LO12: return ":got_lo12:";
68 case VK_GOTTPREL_PAGE: return ":gottprel:";
69 case VK_GOTTPREL_LO12_NC: return ":gottprel_lo12:";
70 case VK_GOTTPREL_G1: return ":gottprel_g1:";
71 case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:";
72 case VK_TLSDESC: return "";
73 case VK_TLSDESC_PAGE: return ":tlsdesc:";
74 default:
75 llvm_unreachable("Invalid ELF symbol kind");
76 }
77 }
78
PrintImpl(raw_ostream & OS) const79 void AArch64MCExpr::PrintImpl(raw_ostream &OS) const {
80 if (getKind() != VK_NONE)
81 OS << getVariantKindName();
82 OS << *Expr;
83 }
84
visitUsedExpr(MCStreamer & Streamer) const85 void AArch64MCExpr::visitUsedExpr(MCStreamer &Streamer) const {
86 Streamer.visitUsedExpr(*getSubExpr());
87 }
88
FindAssociatedSection() const89 const MCSection *AArch64MCExpr::FindAssociatedSection() const {
90 llvm_unreachable("FIXME: what goes here?");
91 }
92
EvaluateAsRelocatableImpl(MCValue & Res,const MCAsmLayout * Layout,const MCFixup * Fixup) const93 bool AArch64MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
94 const MCAsmLayout *Layout,
95 const MCFixup *Fixup) const {
96 if (!getSubExpr()->EvaluateAsRelocatable(Res, Layout, Fixup))
97 return false;
98
99 Res =
100 MCValue::get(Res.getSymA(), Res.getSymB(), Res.getConstant(), getKind());
101
102 return true;
103 }
104
fixELFSymbolsInTLSFixupsImpl(const MCExpr * Expr,MCAssembler & Asm)105 static void fixELFSymbolsInTLSFixupsImpl(const MCExpr *Expr, MCAssembler &Asm) {
106 switch (Expr->getKind()) {
107 case MCExpr::Target:
108 llvm_unreachable("Can't handle nested target expression");
109 break;
110 case MCExpr::Constant:
111 break;
112
113 case MCExpr::Binary: {
114 const MCBinaryExpr *BE = cast<MCBinaryExpr>(Expr);
115 fixELFSymbolsInTLSFixupsImpl(BE->getLHS(), Asm);
116 fixELFSymbolsInTLSFixupsImpl(BE->getRHS(), Asm);
117 break;
118 }
119
120 case MCExpr::SymbolRef: {
121 // We're known to be under a TLS fixup, so any symbol should be
122 // modified. There should be only one.
123 const MCSymbolRefExpr &SymRef = *cast<MCSymbolRefExpr>(Expr);
124 MCSymbolData &SD = Asm.getOrCreateSymbolData(SymRef.getSymbol());
125 MCELF::SetType(SD, ELF::STT_TLS);
126 break;
127 }
128
129 case MCExpr::Unary:
130 fixELFSymbolsInTLSFixupsImpl(cast<MCUnaryExpr>(Expr)->getSubExpr(), Asm);
131 break;
132 }
133 }
134
fixELFSymbolsInTLSFixups(MCAssembler & Asm) const135 void AArch64MCExpr::fixELFSymbolsInTLSFixups(MCAssembler &Asm) const {
136 switch (getSymbolLoc(Kind)) {
137 default:
138 return;
139 case VK_DTPREL:
140 case VK_GOTTPREL:
141 case VK_TPREL:
142 case VK_TLSDESC:
143 break;
144 }
145
146 fixELFSymbolsInTLSFixupsImpl(getSubExpr(), Asm);
147 }
148