1 //===- MCAsmBackend.cpp - Target MC Assembly Backend ----------------------===//
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 #include "llvm/MC/MCAsmBackend.h"
11 #include "llvm/ADT/None.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/MC/MCCodePadder.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include <cassert>
16 #include <cstddef>
17 #include <cstdint>
18 
19 using namespace llvm;
20 
21 MCAsmBackend::MCAsmBackend() : CodePadder(new MCCodePadder()) {}
22 
23 MCAsmBackend::MCAsmBackend(std::unique_ptr<MCCodePadder> TargetCodePadder)
24     : CodePadder(std::move(TargetCodePadder)) {}
25 
26 MCAsmBackend::~MCAsmBackend() = default;
27 
28 Optional<MCFixupKind> MCAsmBackend::getFixupKind(StringRef Name) const {
29   return None;
30 }
31 
32 const MCFixupKindInfo &MCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
33   static const MCFixupKindInfo Builtins[] = {
34       {"FK_Data_1", 0, 8, 0},
35       {"FK_Data_2", 0, 16, 0},
36       {"FK_Data_4", 0, 32, 0},
37       {"FK_Data_8", 0, 64, 0},
38       {"FK_PCRel_1", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
39       {"FK_PCRel_2", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
40       {"FK_PCRel_4", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
41       {"FK_PCRel_8", 0, 64, MCFixupKindInfo::FKF_IsPCRel},
42       {"FK_GPRel_1", 0, 8, 0},
43       {"FK_GPRel_2", 0, 16, 0},
44       {"FK_GPRel_4", 0, 32, 0},
45       {"FK_GPRel_8", 0, 64, 0},
46       {"FK_DTPRel_4", 0, 32, 0},
47       {"FK_DTPRel_8", 0, 64, 0},
48       {"FK_TPRel_4", 0, 32, 0},
49       {"FK_TPRel_8", 0, 64, 0},
50       {"FK_SecRel_1", 0, 8, 0},
51       {"FK_SecRel_2", 0, 16, 0},
52       {"FK_SecRel_4", 0, 32, 0},
53       {"FK_SecRel_8", 0, 64, 0}};
54 
55   assert((size_t)Kind <= array_lengthof(Builtins) && "Unknown fixup kind");
56   return Builtins[Kind];
57 }
58 
59 bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
60     const MCFixup &Fixup, bool Resolved, uint64_t Value,
61     const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const {
62   if (!Resolved)
63     return true;
64   return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
65 }
66 
67 void MCAsmBackend::handleCodePaddingBasicBlockStart(
68     MCObjectStreamer *OS, const MCCodePaddingContext &Context) {
69   CodePadder->handleBasicBlockStart(OS, Context);
70 }
71 
72 void MCAsmBackend::handleCodePaddingBasicBlockEnd(
73     const MCCodePaddingContext &Context) {
74   CodePadder->handleBasicBlockEnd(Context);
75 }
76 
77 void MCAsmBackend::handleCodePaddingInstructionBegin(const MCInst &Inst) {
78   CodePadder->handleInstructionBegin(Inst);
79 }
80 
81 void MCAsmBackend::handleCodePaddingInstructionEnd(const MCInst &Inst) {
82   CodePadder->handleInstructionEnd(Inst);
83 }
84 
85 bool MCAsmBackend::relaxFragment(MCPaddingFragment *PF, MCAsmLayout &Layout) {
86   return CodePadder->relaxFragment(PF, Layout);
87 }