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/ADT/DenseMap.h"
14 #include "llvm/ADT/StringMap.h"
15 #include "llvm/Support/Allocator.h"
25 /// MCContext - Context object for machine code objects. This class owns all
26 /// of the sections that it creates.
29 MCContext(const MCContext&); // DO NOT IMPLEMENT
30 MCContext &operator=(const MCContext&); // DO NOT IMPLEMENT
32 /// The MCAsmInfo for this target.
35 /// Sections - Bindings of names to allocated sections.
36 StringMap<MCSection*> Sections;
38 /// Symbols - Bindings of names to symbols.
39 StringMap<MCSymbol*> Symbols;
41 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
43 unsigned NextUniqueID;
45 /// Allocator - Allocator object used for creating machine code objects.
47 /// We use a bump pointer allocator to avoid the need to track all allocated
49 BumpPtrAllocator Allocator;
51 MCContext(const MCAsmInfo &MAI);
54 const MCAsmInfo &getAsmInfo() const { return MAI; }
56 /// @name Symbol Managment
59 /// GetOrCreateSymbol - Lookup the symbol inside with the specified
60 /// @p Name. If it exists, return it. If not, create a forward
61 /// reference and return it.
63 /// @param Name - The symbol name, which must be unique across all symbols.
64 MCSymbol *GetOrCreateSymbol(StringRef Name);
65 MCSymbol *GetOrCreateSymbol(const Twine &Name);
67 /// GetOrCreateTemporarySymbol - Create a new assembler temporary symbol
68 /// with the specified @p Name if it doesn't exist or return the existing
71 /// @param Name - The symbol name, for debugging purposes only, temporary
72 /// symbols do not surive assembly. If non-empty the name must be unique
73 /// across all symbols.
74 MCSymbol *GetOrCreateTemporarySymbol(StringRef Name = "");
75 MCSymbol *GetOrCreateTemporarySymbol(const Twine &Name);
77 /// LookupSymbol - Get the symbol for \p Name, or null.
78 MCSymbol *LookupSymbol(StringRef Name) const;
82 void *Allocate(unsigned Size, unsigned Align = 8) {
83 return Allocator.Allocate(Size, Align);
85 void Deallocate(void *Ptr) {
89 } // end namespace llvm
91 // operator new and delete aren't allowed inside namespaces.
92 // The throw specifications are mandated by the standard.
93 /// @brief Placement new for using the MCContext's allocator.
95 /// This placement form of operator new uses the MCContext's allocator for
96 /// obtaining memory. It is a non-throwing new, which means that it returns
97 /// null on error. (If that is what the allocator does. The current does, so if
98 /// this ever changes, this operator will have to be changed, too.)
99 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
101 /// // Default alignment (16)
102 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
103 /// // Specific alignment
104 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
106 /// Please note that you cannot use delete on the pointer; it must be
107 /// deallocated using an explicit destructor call followed by
108 /// @c Context.Deallocate(Ptr).
110 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
111 /// @param C The MCContext that provides the allocator.
112 /// @param Alignment The alignment of the allocated memory (if the underlying
113 /// allocator supports it).
114 /// @return The allocated memory. Could be NULL.
115 inline void *operator new(size_t Bytes, llvm::MCContext &C,
116 size_t Alignment = 16) throw () {
117 return C.Allocate(Bytes, Alignment);
119 /// @brief Placement delete companion to the new above.
121 /// This operator is just a companion to the new above. There is no way of
122 /// invoking it directly; see the new operator for more details. This operator
123 /// is called implicitly by the compiler if a placement new expression using
124 /// the MCContext throws in the object constructor.
125 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
130 /// This placement form of operator new[] uses the MCContext's allocator for
131 /// obtaining memory. It is a non-throwing new[], which means that it returns
133 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
135 /// // Default alignment (16)
136 /// char *data = new (Context) char[10];
137 /// // Specific alignment
138 /// char *data = new (Context, 8) char[10];
140 /// Please note that you cannot use delete on the pointer; it must be
141 /// deallocated using an explicit destructor call followed by
142 /// @c Context.Deallocate(Ptr).
144 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
145 /// @param C The MCContext that provides the allocator.
146 /// @param Alignment The alignment of the allocated memory (if the underlying
147 /// allocator supports it).
148 /// @return The allocated memory. Could be NULL.
149 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
150 size_t Alignment = 16) throw () {
151 return C.Allocate(Bytes, Alignment);
154 /// @brief Placement delete[] companion to the new[] above.
156 /// This operator is just a companion to the new[] above. There is no way of
157 /// invoking it directly; see the new[] operator for more details. This operator
158 /// is called implicitly by the compiler if a placement new[] expression using
159 /// the MCContext throws in the object constructor.
160 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {