2010-02-21 21:53:53 +00:00
|
|
|
//===-- llvm/Target/TargetAsmBackend.h - Target Asm Backend -----*- C++ -*-===//
|
|
|
|
//
|
|
|
|
// The LLVM Compiler Infrastructure
|
|
|
|
//
|
|
|
|
// This file is distributed under the University of Illinois Open Source
|
|
|
|
// License. See LICENSE.TXT for details.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
|
|
#ifndef LLVM_TARGET_TARGETASMBACKEND_H
|
|
|
|
#define LLVM_TARGET_TARGETASMBACKEND_H
|
|
|
|
|
2010-03-19 09:28:12 +00:00
|
|
|
#include "llvm/System/DataTypes.h"
|
|
|
|
|
2010-02-21 21:53:53 +00:00
|
|
|
namespace llvm {
|
2010-03-19 09:28:12 +00:00
|
|
|
class MCAsmFixup;
|
|
|
|
class MCDataFragment;
|
2010-03-15 21:56:50 +00:00
|
|
|
class MCSection;
|
2010-02-21 21:53:53 +00:00
|
|
|
class Target;
|
|
|
|
|
|
|
|
/// TargetAsmBackend - Generic interface to target specific assembler backends.
|
|
|
|
class TargetAsmBackend {
|
|
|
|
TargetAsmBackend(const TargetAsmBackend &); // DO NOT IMPLEMENT
|
|
|
|
void operator=(const TargetAsmBackend &); // DO NOT IMPLEMENT
|
|
|
|
protected: // Can only create subclasses.
|
|
|
|
TargetAsmBackend(const Target &);
|
|
|
|
|
|
|
|
/// TheTarget - The Target that this machine was created for.
|
|
|
|
const Target &TheTarget;
|
|
|
|
|
2010-03-18 00:58:53 +00:00
|
|
|
unsigned HasAbsolutizedSet : 1;
|
|
|
|
unsigned HasReliableSymbolDifference : 1;
|
|
|
|
unsigned HasScatteredSymbols : 1;
|
|
|
|
|
2010-02-21 21:53:53 +00:00
|
|
|
public:
|
|
|
|
virtual ~TargetAsmBackend();
|
|
|
|
|
|
|
|
const Target &getTarget() const { return TheTarget; }
|
|
|
|
|
2010-03-11 01:34:21 +00:00
|
|
|
/// hasAbsolutizedSet - Check whether this target "absolutizes"
|
|
|
|
/// assignments. That is, given code like:
|
|
|
|
/// a:
|
|
|
|
/// ...
|
|
|
|
/// b:
|
|
|
|
/// tmp = a - b
|
|
|
|
/// .long tmp
|
|
|
|
/// will the value of 'tmp' be a relocatable expression, or the assembly time
|
|
|
|
/// value of L0 - L1. This distinction is only relevant for platforms that
|
|
|
|
/// support scattered symbols, since in the absence of scattered symbols (a -
|
|
|
|
/// b) cannot change after assembly.
|
2010-03-18 00:58:53 +00:00
|
|
|
bool hasAbsolutizedSet() const { return HasAbsolutizedSet; }
|
|
|
|
|
|
|
|
/// hasReliableSymbolDifference - Check whether this target implements
|
|
|
|
/// accurate relocations for differences between symbols. If not, differences
|
|
|
|
/// between symbols will always be relocatable expressions and any references
|
|
|
|
/// to temporary symbols will be assumed to be in the same atom, unless they
|
|
|
|
/// reside in a different section.
|
|
|
|
///
|
|
|
|
/// This should always be true (since it results in fewer relocations with no
|
|
|
|
/// loss of functionality), but is currently supported as a way to maintain
|
|
|
|
/// exact object compatibility with Darwin 'as' (on non-x86_64). It should
|
|
|
|
/// eventually should be eliminated. See also \see hasAbsolutizedSet.
|
|
|
|
bool hasReliableSymbolDifference() const {
|
|
|
|
return HasReliableSymbolDifference;
|
|
|
|
}
|
2010-03-11 01:34:21 +00:00
|
|
|
|
|
|
|
/// hasScatteredSymbols - Check whether this target supports scattered
|
|
|
|
/// symbols. If so, the assembler should assume that atoms can be scattered by
|
|
|
|
/// the linker. In particular, this means that the offsets between symbols
|
|
|
|
/// which are in distinct atoms is not known at link time, and the assembler
|
|
|
|
/// must generate fixups and relocations appropriately.
|
|
|
|
///
|
|
|
|
/// Note that the assembler currently does not reason about atoms, instead it
|
|
|
|
/// assumes all temporary symbols reside in the "current atom".
|
2010-03-18 00:58:53 +00:00
|
|
|
bool hasScatteredSymbols() const { return HasScatteredSymbols; }
|
2010-03-15 21:56:50 +00:00
|
|
|
|
|
|
|
/// doesSectionRequireSymbols - Check whether the given section requires that
|
|
|
|
/// all symbols (even temporaries) have symbol table entries.
|
|
|
|
virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
|
|
|
|
return false;
|
|
|
|
}
|
2010-03-19 09:28:12 +00:00
|
|
|
|
|
|
|
/// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
|
|
|
|
/// data fragment, at the offset specified by the fixup and following the
|
|
|
|
/// fixup kind as appropriate.
|
|
|
|
virtual void ApplyFixup(const MCAsmFixup &Fixup, MCDataFragment &Fragment,
|
|
|
|
uint64_t Value) const = 0;
|
2010-02-21 21:53:53 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
} // End llvm namespace
|
|
|
|
|
|
|
|
#endif
|