LLVM  4.0.0
SystemZMCObjectWriter.cpp
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1 //===-- SystemZMCObjectWriter.cpp - SystemZ ELF writer --------------------===//
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 
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCValue.h"
15 
16 using namespace llvm;
17 
18 namespace {
19 class SystemZObjectWriter : public MCELFObjectTargetWriter {
20 public:
21  SystemZObjectWriter(uint8_t OSABI);
22 
23  ~SystemZObjectWriter() override;
24 
25 protected:
26  // Override MCELFObjectTargetWriter.
27  unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
28  const MCFixup &Fixup, bool IsPCRel) const override;
29 };
30 } // end anonymous namespace
31 
32 SystemZObjectWriter::SystemZObjectWriter(uint8_t OSABI)
33  : MCELFObjectTargetWriter(/*Is64Bit=*/true, OSABI, ELF::EM_S390,
34  /*HasRelocationAddend=*/ true) {}
35 
36 SystemZObjectWriter::~SystemZObjectWriter() {
37 }
38 
39 // Return the relocation type for an absolute value of MCFixupKind Kind.
40 static unsigned getAbsoluteReloc(unsigned Kind) {
41  switch (Kind) {
42  case FK_Data_1: return ELF::R_390_8;
43  case FK_Data_2: return ELF::R_390_16;
44  case FK_Data_4: return ELF::R_390_32;
45  case FK_Data_8: return ELF::R_390_64;
46  }
47  llvm_unreachable("Unsupported absolute address");
48 }
49 
50 // Return the relocation type for a PC-relative value of MCFixupKind Kind.
51 static unsigned getPCRelReloc(unsigned Kind) {
52  switch (Kind) {
53  case FK_Data_2: return ELF::R_390_PC16;
54  case FK_Data_4: return ELF::R_390_PC32;
55  case FK_Data_8: return ELF::R_390_PC64;
56  case SystemZ::FK_390_PC12DBL: return ELF::R_390_PC12DBL;
57  case SystemZ::FK_390_PC16DBL: return ELF::R_390_PC16DBL;
58  case SystemZ::FK_390_PC24DBL: return ELF::R_390_PC24DBL;
59  case SystemZ::FK_390_PC32DBL: return ELF::R_390_PC32DBL;
60  }
61  llvm_unreachable("Unsupported PC-relative address");
62 }
63 
64 // Return the R_390_TLS_LE* relocation type for MCFixupKind Kind.
65 static unsigned getTLSLEReloc(unsigned Kind) {
66  switch (Kind) {
67  case FK_Data_4: return ELF::R_390_TLS_LE32;
68  case FK_Data_8: return ELF::R_390_TLS_LE64;
69  }
70  llvm_unreachable("Unsupported absolute address");
71 }
72 
73 // Return the R_390_TLS_LDO* relocation type for MCFixupKind Kind.
74 static unsigned getTLSLDOReloc(unsigned Kind) {
75  switch (Kind) {
76  case FK_Data_4: return ELF::R_390_TLS_LDO32;
77  case FK_Data_8: return ELF::R_390_TLS_LDO64;
78  }
79  llvm_unreachable("Unsupported absolute address");
80 }
81 
82 // Return the R_390_TLS_LDM* relocation type for MCFixupKind Kind.
83 static unsigned getTLSLDMReloc(unsigned Kind) {
84  switch (Kind) {
85  case FK_Data_4: return ELF::R_390_TLS_LDM32;
86  case FK_Data_8: return ELF::R_390_TLS_LDM64;
87  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_LDCALL;
88  }
89  llvm_unreachable("Unsupported absolute address");
90 }
91 
92 // Return the R_390_TLS_GD* relocation type for MCFixupKind Kind.
93 static unsigned getTLSGDReloc(unsigned Kind) {
94  switch (Kind) {
95  case FK_Data_4: return ELF::R_390_TLS_GD32;
96  case FK_Data_8: return ELF::R_390_TLS_GD64;
97  case SystemZ::FK_390_TLS_CALL: return ELF::R_390_TLS_GDCALL;
98  }
99  llvm_unreachable("Unsupported absolute address");
100 }
101 
102 // Return the PLT relocation counterpart of MCFixupKind Kind.
103 static unsigned getPLTReloc(unsigned Kind) {
104  switch (Kind) {
105  case SystemZ::FK_390_PC12DBL: return ELF::R_390_PLT12DBL;
106  case SystemZ::FK_390_PC16DBL: return ELF::R_390_PLT16DBL;
107  case SystemZ::FK_390_PC24DBL: return ELF::R_390_PLT24DBL;
108  case SystemZ::FK_390_PC32DBL: return ELF::R_390_PLT32DBL;
109  }
110  llvm_unreachable("Unsupported absolute address");
111 }
112 
114  const MCValue &Target,
115  const MCFixup &Fixup,
116  bool IsPCRel) const {
118  unsigned Kind = Fixup.getKind();
119  switch (Modifier) {
121  if (IsPCRel)
122  return getPCRelReloc(Kind);
123  return getAbsoluteReloc(Kind);
124 
126  assert(!IsPCRel && "NTPOFF shouldn't be PC-relative");
127  return getTLSLEReloc(Kind);
128 
130  if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
131  return ELF::R_390_TLS_IEENT;
132  llvm_unreachable("Only PC-relative INDNTPOFF accesses are supported for now");
133 
135  assert(!IsPCRel && "DTPOFF shouldn't be PC-relative");
136  return getTLSLDOReloc(Kind);
137 
139  assert(!IsPCRel && "TLSLDM shouldn't be PC-relative");
140  return getTLSLDMReloc(Kind);
141 
143  assert(!IsPCRel && "TLSGD shouldn't be PC-relative");
144  return getTLSGDReloc(Kind);
145 
147  if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
148  return ELF::R_390_GOTENT;
149  llvm_unreachable("Only PC-relative GOT accesses are supported for now");
150 
152  assert(IsPCRel && "@PLT shouldt be PC-relative");
153  return getPLTReloc(Kind);
154 
155  default:
156  llvm_unreachable("Modifier not supported");
157  }
158 }
159 
161  uint8_t OSABI) {
162  MCELFObjectTargetWriter *MOTW = new SystemZObjectWriter(OSABI);
163  return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/false);
164 }
This represents an "assembler immediate".
Definition: MCValue.h:40
Defines the object file and target independent interfaces used by the assembler backend to write nati...
static unsigned getTLSGDReloc(unsigned Kind)
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:66
static unsigned getRelocType(const MCValue &Target, const MCFixupKind FixupKind, const bool IsPCRel)
Translates generic PPC fixup kind to Mach-O/PPC relocation type enum.
A four-byte fixup.
Definition: MCFixup.h:26
static unsigned getPCRelReloc(unsigned Kind)
Context object for machine code objects.
Definition: MCContext.h:51
static unsigned getTLSLEReloc(unsigned Kind)
MCSymbolRefExpr::VariantKind getAccessVariant() const
Definition: MCValue.cpp:44
MCObjectWriter * createSystemZObjectWriter(raw_pwrite_stream &OS, uint8_t OSABI)
static unsigned getPLTReloc(unsigned Kind)
static unsigned getTLSLDMReloc(unsigned Kind)
MCFixupKind getKind() const
Definition: MCFixup.h:93
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
A one-byte fixup.
Definition: MCFixup.h:24
static unsigned getAbsoluteReloc(unsigned Kind)
Target - Wrapper for Target specific information.
MCObjectWriter * createELFObjectWriter(MCELFObjectTargetWriter *MOTW, raw_pwrite_stream &OS, bool IsLittleEndian)
Construct a new ELF writer instance.
Basic Alias true
A eight-byte fixup.
Definition: MCFixup.h:27
static unsigned getTLSLDOReloc(unsigned Kind)
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:333
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
A two-byte fixup.
Definition: MCFixup.h:25