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Diffstat (limited to 'include/llvm/MC/MCContext.h')
| -rw-r--r-- | include/llvm/MC/MCContext.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h new file mode 100644 index 0000000..13180e8 --- /dev/null +++ b/include/llvm/MC/MCContext.h @@ -0,0 +1,166 @@ +//===- MCContext.h - Machine Code Context -----------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_MC_MCCONTEXT_H +#define LLVM_MC_MCCONTEXT_H + +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/StringMap.h" +#include "llvm/Support/Allocator.h" + +namespace llvm { + class MCValue; + class MCSection; + class MCSymbol; + + /// MCContext - Context object for machine code objects. + class MCContext { + MCContext(const MCContext&); // DO NOT IMPLEMENT + MCContext &operator=(const MCContext&); // DO NOT IMPLEMENT + + /// Sections - Bindings of names to allocated sections. + StringMap<MCSection*> Sections; + + /// Symbols - Bindings of names to symbols. + StringMap<MCSymbol*> Symbols; + + /// SymbolValues - Bindings of symbols to values. + DenseMap<MCSymbol*, MCValue> SymbolValues; + + /// Allocator - Allocator object used for creating machine code objects. + /// + /// We use a bump pointer allocator to avoid the need to track all allocated + /// objects. + BumpPtrAllocator Allocator; + + public: + MCContext(); + ~MCContext(); + + /// GetSection - Get or create a new section with the given @param Name. + MCSection *GetSection(const char *Name); + + /// CreateSymbol - Create a new symbol with the specified @param Name. + /// + /// @param Name - The symbol name, which must be unique across all symbols. + MCSymbol *CreateSymbol(const char *Name); + + /// GetOrCreateSymbol - Lookup the symbol inside with the specified + /// @param Name. If it exists, return it. If not, create a forward + /// reference and return it. + /// + /// @param Name - The symbol name, which must be unique across all symbols. + MCSymbol *GetOrCreateSymbol(const char *Name); + + /// CreateTemporarySymbol - Create a new temporary symbol with the specified + /// @param Name. + /// + /// @param Name - The symbol name, for debugging purposes only, temporary + /// symbols do not surive assembly. If non-empty the name must be unique + /// across all symbols. + MCSymbol *CreateTemporarySymbol(const char *Name = ""); + + /// LookupSymbol - Get the symbol for @param Name, or null. + MCSymbol *LookupSymbol(const char *Name) const; + + /// ClearSymbolValue - Erase a value binding for @param Symbol, if one + /// exists. + void ClearSymbolValue(MCSymbol *Symbol); + + /// SetSymbolValue - Set the value binding for @param Symbol to @param + /// Value. + void SetSymbolValue(MCSymbol *Symbol, const MCValue &Value); + + /// GetSymbolValue - Return the current value for @param Symbol, or null if + /// none exists. + const MCValue *GetSymbolValue(MCSymbol *Symbol) const; + + void *Allocate(unsigned Size, unsigned Align = 8) { + return Allocator.Allocate(Size, Align); + } + void Deallocate(void *Ptr) { + } + }; + +} // end namespace llvm + +// operator new and delete aren't allowed inside namespaces. +// The throw specifications are mandated by the standard. +/// @brief Placement new for using the MCContext's allocator. +/// +/// This placement form of operator new uses the MCContext's allocator for +/// obtaining memory. It is a non-throwing new, which means that it returns +/// null on error. (If that is what the allocator does. The current does, so if +/// this ever changes, this operator will have to be changed, too.) +/// Usage looks like this (assuming there's an MCContext 'Context' in scope): +/// @code +/// // Default alignment (16) +/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments); +/// // Specific alignment +/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments); +/// @endcode +/// Please note that you cannot use delete on the pointer; it must be +/// deallocated using an explicit destructor call followed by +/// @c Context.Deallocate(Ptr). +/// +/// @param Bytes The number of bytes to allocate. Calculated by the compiler. +/// @param C The MCContext that provides the allocator. +/// @param Alignment The alignment of the allocated memory (if the underlying +/// allocator supports it). +/// @return The allocated memory. Could be NULL. +inline void *operator new(size_t Bytes, llvm::MCContext &C, + size_t Alignment = 16) throw () { + return C.Allocate(Bytes, Alignment); +} +/// @brief Placement delete companion to the new above. +/// +/// This operator is just a companion to the new above. There is no way of +/// invoking it directly; see the new operator for more details. This operator +/// is called implicitly by the compiler if a placement new expression using +/// the MCContext throws in the object constructor. +inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) + throw () { + C.Deallocate(Ptr); +} + +/// This placement form of operator new[] uses the MCContext's allocator for +/// obtaining memory. It is a non-throwing new[], which means that it returns +/// null on error. +/// Usage looks like this (assuming there's an MCContext 'Context' in scope): +/// @code +/// // Default alignment (16) +/// char *data = new (Context) char[10]; +/// // Specific alignment +/// char *data = new (Context, 8) char[10]; +/// @endcode +/// Please note that you cannot use delete on the pointer; it must be +/// deallocated using an explicit destructor call followed by +/// @c Context.Deallocate(Ptr). +/// +/// @param Bytes The number of bytes to allocate. Calculated by the compiler. +/// @param C The MCContext that provides the allocator. +/// @param Alignment The alignment of the allocated memory (if the underlying +/// allocator supports it). +/// @return The allocated memory. Could be NULL. +inline void *operator new[](size_t Bytes, llvm::MCContext& C, + size_t Alignment = 16) throw () { + return C.Allocate(Bytes, Alignment); +} + +/// @brief Placement delete[] companion to the new[] above. +/// +/// This operator is just a companion to the new[] above. There is no way of +/// invoking it directly; see the new[] operator for more details. This operator +/// is called implicitly by the compiler if a placement new[] expression using +/// the MCContext throws in the object constructor. +inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () { + C.Deallocate(Ptr); +} + +#endif |
