1 //===- MCSectionWasm.h - Wasm Machine Code Sections -------------*- C++ -*-===//
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 declares the MCSectionWasm class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_MC_MCSECTIONWASM_H
14 #define LLVM_MC_MCSECTIONWASM_H
15 
16 #include "llvm/ADT/Twine.h"
17 #include "llvm/MC/MCSection.h"
18 #include "llvm/MC/MCSymbolWasm.h"
19 #include "llvm/Support/Debug.h"
20 #include "llvm/Support/raw_ostream.h"
21 
22 namespace llvm {
23 
24 class MCSymbol;
25 
26 /// This represents a section on wasm.
27 class MCSectionWasm final : public MCSection {
28   /// This is the name of the section.  The referenced memory is owned by
29   /// TargetLoweringObjectFileWasm's WasmUniqueMap.
30   StringRef SectionName;
31 
32   unsigned UniqueID;
33 
34   const MCSymbolWasm *Group;
35 
36   // The offset of the MC function/data section in the wasm code/data section.
37   // For data relocations the offset is relative to start of the data payload
38   // itself and does not include the size of the section header.
39   uint64_t SectionOffset = 0;
40 
41   // For data sections, this is the index of of the corresponding wasm data
42   // segment
43   uint32_t SegmentIndex = 0;
44 
45   // Whether this data segment is passive
46   bool IsPassive = false;
47 
48   friend class MCContext;
MCSectionWasm(StringRef Section,SectionKind K,const MCSymbolWasm * group,unsigned UniqueID,MCSymbol * Begin)49   MCSectionWasm(StringRef Section, SectionKind K, const MCSymbolWasm *group,
50                 unsigned UniqueID, MCSymbol *Begin)
51       : MCSection(SV_Wasm, K, Begin), SectionName(Section), UniqueID(UniqueID),
52         Group(group) {}
53 
54 public:
55   /// Decides whether a '.section' directive should be printed before the
56   /// section name
57   bool shouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
58 
getSectionName()59   StringRef getSectionName() const { return SectionName; }
getGroup()60   const MCSymbolWasm *getGroup() const { return Group; }
61 
62   void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
63                             raw_ostream &OS,
64                             const MCExpr *Subsection) const override;
65   bool UseCodeAlign() const override;
66   bool isVirtualSection() const override;
67 
isWasmData()68   bool isWasmData() const {
69     return Kind.isGlobalWriteableData() || Kind.isReadOnly() ||
70            Kind.isThreadLocal();
71   }
72 
isUnique()73   bool isUnique() const { return UniqueID != ~0U; }
getUniqueID()74   unsigned getUniqueID() const { return UniqueID; }
75 
getSectionOffset()76   uint64_t getSectionOffset() const { return SectionOffset; }
setSectionOffset(uint64_t Offset)77   void setSectionOffset(uint64_t Offset) { SectionOffset = Offset; }
78 
getSegmentIndex()79   uint32_t getSegmentIndex() const { return SegmentIndex; }
setSegmentIndex(uint32_t Index)80   void setSegmentIndex(uint32_t Index) { SegmentIndex = Index; }
81 
getPassive()82   bool getPassive() const {
83     assert(isWasmData());
84     return IsPassive;
85   }
86   void setPassive(bool V = true) {
87     assert(isWasmData());
88     IsPassive = V;
89   }
classof(const MCSection * S)90   static bool classof(const MCSection *S) { return S->getVariant() == SV_Wasm; }
91 };
92 
93 } // end namespace llvm
94 
95 #endif
96