llvm-6502/include/llvm/MC/MCExpr.h
Rafael Espindola 1c509556ee Add an option for evaluating past symbols.
When evaluating an assembly expression for a relocation, we want to
stop at MCSymbols that are in the symbol table, even if they are variables.
This is needed since the semantics may require that the relocation use them.

That is not the case when computing the value of a symbol in the symbol table.
There are no relocations in this case and we have to keep going until we hit
a section or find out that the expression doesn't have an assembly time
value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207445 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 20:53:11 +00:00

538 lines
17 KiB
C++

//===- MCExpr.h - Assembly Level Expressions --------------------*- 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_MCEXPR_H
#define LLVM_MC_MCEXPR_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class MCAsmInfo;
class MCAsmLayout;
class MCAssembler;
class MCContext;
class MCSection;
class MCSectionData;
class MCSymbol;
class MCValue;
class raw_ostream;
class StringRef;
typedef DenseMap<const MCSectionData*, uint64_t> SectionAddrMap;
/// MCExpr - Base class for the full range of assembler expressions which are
/// needed for parsing.
class MCExpr {
public:
enum ExprKind {
Binary, ///< Binary expressions.
Constant, ///< Constant expressions.
SymbolRef, ///< References to labels and assigned expressions.
Unary, ///< Unary expressions.
Target ///< Target specific expression.
};
private:
ExprKind Kind;
MCExpr(const MCExpr&) LLVM_DELETED_FUNCTION;
void operator=(const MCExpr&) LLVM_DELETED_FUNCTION;
bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs) const;
protected:
explicit MCExpr(ExprKind _Kind) : Kind(_Kind) {}
bool EvaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
const MCAsmLayout *Layout,
const SectionAddrMap *Addrs, bool InSet,
bool ForceVarExpansion) const;
public:
/// @name Accessors
/// @{
ExprKind getKind() const { return Kind; }
/// @}
/// @name Utility Methods
/// @{
void print(raw_ostream &OS) const;
void dump() const;
/// @}
/// @name Expression Evaluation
/// @{
/// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
///
/// @param Res - The absolute value, if evaluation succeeds.
/// @param Layout - The assembler layout object to use for evaluating symbol
/// values. If not given, then only non-symbolic expressions will be
/// evaluated.
/// @result - True on success.
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout,
const SectionAddrMap &Addrs) const;
bool EvaluateAsAbsolute(int64_t &Res) const;
bool EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const;
bool EvaluateAsAbsolute(int64_t &Res, const MCAsmLayout &Layout) const;
/// EvaluateAsRelocatable - Try to evaluate the expression to a relocatable
/// value, i.e. an expression of the fixed form (a - b + constant).
///
/// @param Res - The relocatable value, if evaluation succeeds.
/// @param Layout - The assembler layout object to use for evaluating values.
/// @result - True on success.
bool EvaluateAsRelocatable(MCValue &Res, const MCAsmLayout *Layout) const;
/// \brief Try to evaluate the expression to the form (a - b + constant) where
/// neither a nor b are variables.
///
/// This is a more aggressive variant of EvaluateAsRelocatable. The intended
/// use is for when relocations are not available, like the symbol value in
/// the symbol table.
bool EvaluateAsValue(MCValue &Res, const MCAsmLayout *Layout) const;
/// FindAssociatedSection - Find the "associated section" for this expression,
/// which is currently defined as the absolute section for constants, or
/// otherwise the section associated with the first defined symbol in the
/// expression.
const MCSection *FindAssociatedSection() const;
/// @}
};
inline raw_ostream &operator<<(raw_ostream &OS, const MCExpr &E) {
E.print(OS);
return OS;
}
//// MCConstantExpr - Represent a constant integer expression.
class MCConstantExpr : public MCExpr {
int64_t Value;
explicit MCConstantExpr(int64_t _Value)
: MCExpr(MCExpr::Constant), Value(_Value) {}
public:
/// @name Construction
/// @{
static const MCConstantExpr *Create(int64_t Value, MCContext &Ctx);
/// @}
/// @name Accessors
/// @{
int64_t getValue() const { return Value; }
/// @}
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::Constant;
}
};
/// MCSymbolRefExpr - Represent a reference to a symbol from inside an
/// expression.
///
/// A symbol reference in an expression may be a use of a label, a use of an
/// assembler variable (defined constant), or constitute an implicit definition
/// of the symbol as external.
class MCSymbolRefExpr : public MCExpr {
public:
enum VariantKind {
VK_None,
VK_Invalid,
VK_GOT,
VK_GOTOFF,
VK_GOTPCREL,
VK_GOTTPOFF,
VK_INDNTPOFF,
VK_NTPOFF,
VK_GOTNTPOFF,
VK_PLT,
VK_TLSGD,
VK_TLSLD,
VK_TLSLDM,
VK_TPOFF,
VK_DTPOFF,
VK_TLVP, // Mach-O thread local variable relocations
VK_TLVPPAGE,
VK_TLVPPAGEOFF,
VK_PAGE,
VK_PAGEOFF,
VK_GOTPAGE,
VK_GOTPAGEOFF,
VK_SECREL,
VK_WEAKREF, // The link between the symbols in .weakref foo, bar
VK_ARM_NONE,
VK_ARM_TARGET1,
VK_ARM_TARGET2,
VK_ARM_PREL31,
VK_ARM_TLSLDO, // symbol(tlsldo)
VK_ARM_TLSCALL, // symbol(tlscall)
VK_ARM_TLSDESC, // symbol(tlsdesc)
VK_ARM_TLSDESCSEQ,
VK_PPC_LO, // symbol@l
VK_PPC_HI, // symbol@h
VK_PPC_HA, // symbol@ha
VK_PPC_HIGHER, // symbol@higher
VK_PPC_HIGHERA, // symbol@highera
VK_PPC_HIGHEST, // symbol@highest
VK_PPC_HIGHESTA, // symbol@highesta
VK_PPC_GOT_LO, // symbol@got@l
VK_PPC_GOT_HI, // symbol@got@h
VK_PPC_GOT_HA, // symbol@got@ha
VK_PPC_TOCBASE, // symbol@tocbase
VK_PPC_TOC, // symbol@toc
VK_PPC_TOC_LO, // symbol@toc@l
VK_PPC_TOC_HI, // symbol@toc@h
VK_PPC_TOC_HA, // symbol@toc@ha
VK_PPC_DTPMOD, // symbol@dtpmod
VK_PPC_TPREL, // symbol@tprel
VK_PPC_TPREL_LO, // symbol@tprel@l
VK_PPC_TPREL_HI, // symbol@tprel@h
VK_PPC_TPREL_HA, // symbol@tprel@ha
VK_PPC_TPREL_HIGHER, // symbol@tprel@higher
VK_PPC_TPREL_HIGHERA, // symbol@tprel@highera
VK_PPC_TPREL_HIGHEST, // symbol@tprel@highest
VK_PPC_TPREL_HIGHESTA, // symbol@tprel@highesta
VK_PPC_DTPREL, // symbol@dtprel
VK_PPC_DTPREL_LO, // symbol@dtprel@l
VK_PPC_DTPREL_HI, // symbol@dtprel@h
VK_PPC_DTPREL_HA, // symbol@dtprel@ha
VK_PPC_DTPREL_HIGHER, // symbol@dtprel@higher
VK_PPC_DTPREL_HIGHERA, // symbol@dtprel@highera
VK_PPC_DTPREL_HIGHEST, // symbol@dtprel@highest
VK_PPC_DTPREL_HIGHESTA,// symbol@dtprel@highesta
VK_PPC_GOT_TPREL, // symbol@got@tprel
VK_PPC_GOT_TPREL_LO, // symbol@got@tprel@l
VK_PPC_GOT_TPREL_HI, // symbol@got@tprel@h
VK_PPC_GOT_TPREL_HA, // symbol@got@tprel@ha
VK_PPC_GOT_DTPREL, // symbol@got@dtprel
VK_PPC_GOT_DTPREL_LO, // symbol@got@dtprel@l
VK_PPC_GOT_DTPREL_HI, // symbol@got@dtprel@h
VK_PPC_GOT_DTPREL_HA, // symbol@got@dtprel@ha
VK_PPC_TLS, // symbol@tls
VK_PPC_GOT_TLSGD, // symbol@got@tlsgd
VK_PPC_GOT_TLSGD_LO, // symbol@got@tlsgd@l
VK_PPC_GOT_TLSGD_HI, // symbol@got@tlsgd@h
VK_PPC_GOT_TLSGD_HA, // symbol@got@tlsgd@ha
VK_PPC_TLSGD, // symbol@tlsgd
VK_PPC_GOT_TLSLD, // symbol@got@tlsld
VK_PPC_GOT_TLSLD_LO, // symbol@got@tlsld@l
VK_PPC_GOT_TLSLD_HI, // symbol@got@tlsld@h
VK_PPC_GOT_TLSLD_HA, // symbol@got@tlsld@ha
VK_PPC_TLSLD, // symbol@tlsld
VK_Mips_GPREL,
VK_Mips_GOT_CALL,
VK_Mips_GOT16,
VK_Mips_GOT,
VK_Mips_ABS_HI,
VK_Mips_ABS_LO,
VK_Mips_TLSGD,
VK_Mips_TLSLDM,
VK_Mips_DTPREL_HI,
VK_Mips_DTPREL_LO,
VK_Mips_GOTTPREL,
VK_Mips_TPREL_HI,
VK_Mips_TPREL_LO,
VK_Mips_GPOFF_HI,
VK_Mips_GPOFF_LO,
VK_Mips_GOT_DISP,
VK_Mips_GOT_PAGE,
VK_Mips_GOT_OFST,
VK_Mips_HIGHER,
VK_Mips_HIGHEST,
VK_Mips_GOT_HI16,
VK_Mips_GOT_LO16,
VK_Mips_CALL_HI16,
VK_Mips_CALL_LO16,
VK_COFF_IMGREL32 // symbol@imgrel (image-relative)
};
private:
/// The symbol being referenced.
const MCSymbol *Symbol;
/// The symbol reference modifier.
const VariantKind Kind;
/// MCAsmInfo that is used to print symbol variants correctly.
const MCAsmInfo *MAI;
explicit MCSymbolRefExpr(const MCSymbol *_Symbol, VariantKind _Kind,
const MCAsmInfo *_MAI)
: MCExpr(MCExpr::SymbolRef), Symbol(_Symbol), Kind(_Kind), MAI(_MAI) {
assert(Symbol);
assert(MAI);
}
public:
/// @name Construction
/// @{
static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, MCContext &Ctx) {
return MCSymbolRefExpr::Create(Symbol, VK_None, Ctx);
}
static const MCSymbolRefExpr *Create(const MCSymbol *Symbol, VariantKind Kind,
MCContext &Ctx);
static const MCSymbolRefExpr *Create(StringRef Name, VariantKind Kind,
MCContext &Ctx);
/// @}
/// @name Accessors
/// @{
const MCSymbol &getSymbol() const { return *Symbol; }
const MCAsmInfo &getMCAsmInfo() const { return *MAI; }
VariantKind getKind() const { return Kind; }
/// @}
/// @name Static Utility Functions
/// @{
static StringRef getVariantKindName(VariantKind Kind);
static VariantKind getVariantKindForName(StringRef Name);
/// @}
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::SymbolRef;
}
};
/// MCUnaryExpr - Unary assembler expressions.
class MCUnaryExpr : public MCExpr {
public:
enum Opcode {
LNot, ///< Logical negation.
Minus, ///< Unary minus.
Not, ///< Bitwise negation.
Plus ///< Unary plus.
};
private:
Opcode Op;
const MCExpr *Expr;
MCUnaryExpr(Opcode _Op, const MCExpr *_Expr)
: MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
public:
/// @name Construction
/// @{
static const MCUnaryExpr *Create(Opcode Op, const MCExpr *Expr,
MCContext &Ctx);
static const MCUnaryExpr *CreateLNot(const MCExpr *Expr, MCContext &Ctx) {
return Create(LNot, Expr, Ctx);
}
static const MCUnaryExpr *CreateMinus(const MCExpr *Expr, MCContext &Ctx) {
return Create(Minus, Expr, Ctx);
}
static const MCUnaryExpr *CreateNot(const MCExpr *Expr, MCContext &Ctx) {
return Create(Not, Expr, Ctx);
}
static const MCUnaryExpr *CreatePlus(const MCExpr *Expr, MCContext &Ctx) {
return Create(Plus, Expr, Ctx);
}
/// @}
/// @name Accessors
/// @{
/// getOpcode - Get the kind of this unary expression.
Opcode getOpcode() const { return Op; }
/// getSubExpr - Get the child of this unary expression.
const MCExpr *getSubExpr() const { return Expr; }
/// @}
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::Unary;
}
};
/// MCBinaryExpr - Binary assembler expressions.
class MCBinaryExpr : public MCExpr {
public:
enum Opcode {
Add, ///< Addition.
And, ///< Bitwise and.
Div, ///< Signed division.
EQ, ///< Equality comparison.
GT, ///< Signed greater than comparison (result is either 0 or some
///< target-specific non-zero value)
GTE, ///< Signed greater than or equal comparison (result is either 0 or
///< some target-specific non-zero value).
LAnd, ///< Logical and.
LOr, ///< Logical or.
LT, ///< Signed less than comparison (result is either 0 or
///< some target-specific non-zero value).
LTE, ///< Signed less than or equal comparison (result is either 0 or
///< some target-specific non-zero value).
Mod, ///< Signed remainder.
Mul, ///< Multiplication.
NE, ///< Inequality comparison.
Or, ///< Bitwise or.
Shl, ///< Shift left.
Shr, ///< Shift right (arithmetic or logical, depending on target)
Sub, ///< Subtraction.
Xor ///< Bitwise exclusive or.
};
private:
Opcode Op;
const MCExpr *LHS, *RHS;
MCBinaryExpr(Opcode _Op, const MCExpr *_LHS, const MCExpr *_RHS)
: MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
public:
/// @name Construction
/// @{
static const MCBinaryExpr *Create(Opcode Op, const MCExpr *LHS,
const MCExpr *RHS, MCContext &Ctx);
static const MCBinaryExpr *CreateAdd(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Add, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateAnd(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(And, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateDiv(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Div, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateEQ(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(EQ, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateGT(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(GT, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateGTE(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(GTE, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateLAnd(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(LAnd, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateLOr(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(LOr, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateLT(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(LT, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateLTE(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(LTE, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateMod(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Mod, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateMul(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Mul, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateNE(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(NE, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateOr(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Or, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateShl(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Shl, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateShr(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Shr, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateSub(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Sub, LHS, RHS, Ctx);
}
static const MCBinaryExpr *CreateXor(const MCExpr *LHS, const MCExpr *RHS,
MCContext &Ctx) {
return Create(Xor, LHS, RHS, Ctx);
}
/// @}
/// @name Accessors
/// @{
/// getOpcode - Get the kind of this binary expression.
Opcode getOpcode() const { return Op; }
/// getLHS - Get the left-hand side expression of the binary operator.
const MCExpr *getLHS() const { return LHS; }
/// getRHS - Get the right-hand side expression of the binary operator.
const MCExpr *getRHS() const { return RHS; }
/// @}
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::Binary;
}
};
/// MCTargetExpr - This is an extension point for target-specific MCExpr
/// subclasses to implement.
///
/// NOTE: All subclasses are required to have trivial destructors because
/// MCExprs are bump pointer allocated and not destructed.
class MCTargetExpr : public MCExpr {
virtual void anchor();
protected:
MCTargetExpr() : MCExpr(Target) {}
virtual ~MCTargetExpr() {}
public:
virtual void PrintImpl(raw_ostream &OS) const = 0;
virtual bool EvaluateAsRelocatableImpl(MCValue &Res,
const MCAsmLayout *Layout) const = 0;
virtual void AddValueSymbols(MCAssembler *) const = 0;
virtual const MCSection *FindAssociatedSection() const = 0;
virtual void fixELFSymbolsInTLSFixups(MCAssembler &) const = 0;
static bool classof(const MCExpr *E) {
return E->getKind() == MCExpr::Target;
}
};
} // end namespace llvm
#endif