1 //===- MCContext.h - Machine Code Context -----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCCONTEXT_H
11 #define LLVM_MC_MCCONTEXT_H
13 #include "llvm/MC/SectionKind.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include "llvm/ADT/StringMap.h"
16 #include "llvm/Support/Allocator.h"
27 /// MCContext - Context object for machine code objects. This class owns all
28 /// of the sections that it creates.
31 MCContext(const MCContext&); // DO NOT IMPLEMENT
32 MCContext &operator=(const MCContext&); // DO NOT IMPLEMENT
34 /// The MCAsmInfo for this target.
37 /// Sections - Bindings of names to allocated sections.
38 StringMap<MCSection*> Sections;
40 /// Symbols - Bindings of names to symbols.
41 StringMap<MCSymbol*> Symbols;
43 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
45 unsigned NextUniqueID;
47 /// Allocator - Allocator object used for creating machine code objects.
49 /// We use a bump pointer allocator to avoid the need to track all allocated
51 BumpPtrAllocator Allocator;
53 void *MachOUniquingMap, *ELFUniquingMap;
55 explicit MCContext(const MCAsmInfo &MAI);
58 const MCAsmInfo &getAsmInfo() const { return MAI; }
60 /// @name Symbol Managment
63 /// CreateTempSymbol - Create and return a new assembler temporary symbol
64 /// with a unique but unspecified name.
65 MCSymbol *CreateTempSymbol();
67 /// GetOrCreateSymbol - Lookup the symbol inside with the specified
68 /// @p Name. If it exists, return it. If not, create a forward
69 /// reference and return it.
71 /// @param Name - The symbol name, which must be unique across all symbols.
72 MCSymbol *GetOrCreateSymbol(StringRef Name);
73 MCSymbol *GetOrCreateSymbol(const Twine &Name);
75 /// LookupSymbol - Get the symbol for \p Name, or null.
76 MCSymbol *LookupSymbol(StringRef Name) const;
80 /// @name Section Managment
83 /// getMachOSection - Return the MCSection for the specified mach-o section.
84 /// This requires the operands to be valid.
85 const MCSectionMachO *getMachOSection(StringRef Segment,
87 unsigned TypeAndAttributes,
90 const MCSectionMachO *getMachOSection(StringRef Segment,
92 unsigned TypeAndAttributes,
94 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
97 const MCSection *getELFSection(StringRef Section, unsigned Type,
98 unsigned Flags, SectionKind Kind,
99 bool IsExplicit = false);
103 void *Allocate(unsigned Size, unsigned Align = 8) {
104 return Allocator.Allocate(Size, Align);
106 void Deallocate(void *Ptr) {
110 } // end namespace llvm
112 // operator new and delete aren't allowed inside namespaces.
113 // The throw specifications are mandated by the standard.
114 /// @brief Placement new for using the MCContext's allocator.
116 /// This placement form of operator new uses the MCContext's allocator for
117 /// obtaining memory. It is a non-throwing new, which means that it returns
118 /// null on error. (If that is what the allocator does. The current does, so if
119 /// this ever changes, this operator will have to be changed, too.)
120 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
122 /// // Default alignment (16)
123 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
124 /// // Specific alignment
125 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
127 /// Please note that you cannot use delete on the pointer; it must be
128 /// deallocated using an explicit destructor call followed by
129 /// @c Context.Deallocate(Ptr).
131 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
132 /// @param C The MCContext that provides the allocator.
133 /// @param Alignment The alignment of the allocated memory (if the underlying
134 /// allocator supports it).
135 /// @return The allocated memory. Could be NULL.
136 inline void *operator new(size_t Bytes, llvm::MCContext &C,
137 size_t Alignment = 16) throw () {
138 return C.Allocate(Bytes, Alignment);
140 /// @brief Placement delete companion to the new above.
142 /// This operator is just a companion to the new above. There is no way of
143 /// invoking it directly; see the new operator for more details. This operator
144 /// is called implicitly by the compiler if a placement new expression using
145 /// the MCContext throws in the object constructor.
146 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
151 /// This placement form of operator new[] uses the MCContext's allocator for
152 /// obtaining memory. It is a non-throwing new[], which means that it returns
154 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
156 /// // Default alignment (16)
157 /// char *data = new (Context) char[10];
158 /// // Specific alignment
159 /// char *data = new (Context, 8) char[10];
161 /// Please note that you cannot use delete on the pointer; it must be
162 /// deallocated using an explicit destructor call followed by
163 /// @c Context.Deallocate(Ptr).
165 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
166 /// @param C The MCContext that provides the allocator.
167 /// @param Alignment The alignment of the allocated memory (if the underlying
168 /// allocator supports it).
169 /// @return The allocated memory. Could be NULL.
170 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
171 size_t Alignment = 16) throw () {
172 return C.Allocate(Bytes, Alignment);
175 /// @brief Placement delete[] companion to the new[] above.
177 /// This operator is just a companion to the new[] above. There is no way of
178 /// invoking it directly; see the new[] operator for more details. This operator
179 /// is called implicitly by the compiler if a placement new[] expression using
180 /// the MCContext throws in the object constructor.
181 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {