llvm-mc: Move AsmExpr into MC lib (as MCExpr).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80567 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 179 insertions, 0 deletions

diff --git a/include/llvm/MC/MCExpr.h b/include/llvm/MC/MCExpr.h
new file mode 100644
index 0000000000..510ce1a7a6
--- /dev/null
+++ b/include/llvm/MC/MCExpr.h
@@ -0,0 +1,179 @@
+//===- 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/Support/Casting.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+class MCContext;
+class MCSymbol;
+class MCValue;
+
+/// 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.
+  };
+  
+private:
+  ExprKind Kind;
+  
+protected:
+  MCExpr(ExprKind _Kind) : Kind(_Kind) {}
+  
+public:
+  virtual ~MCExpr();
+
+  ExprKind getKind() const { return Kind; }
+
+  /// EvaluateAsAbsolute - Try to evaluate the expression to an absolute value.
+  ///
+  /// @param Res - The absolute value, if evaluation succeeds.
+  /// @result - True on success.
+  bool EvaluateAsAbsolute(MCContext &Ctx, int64_t &Res) 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.
+  /// @result - True on success.
+  bool EvaluateAsRelocatable(MCContext &Ctx, MCValue &Res) const;
+
+  static bool classof(const MCExpr *) { return true; }
+};
+
+//// MCConstantExpr - Represent a constant integer expression.
+class MCConstantExpr : public MCExpr {
+  int64_t Value;
+
+public:
+  MCConstantExpr(int64_t _Value) 
+    : MCExpr(MCExpr::Constant), Value(_Value) {}
+  
+  int64_t getValue() const { return Value; }
+
+  static bool classof(const MCExpr *E) { 
+    return E->getKind() == MCExpr::Constant; 
+  }
+  static bool classof(const MCConstantExpr *) { return true; }
+};
+
+/// 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 {
+  MCSymbol *Symbol;
+
+public:
+  MCSymbolRefExpr(MCSymbol *_Symbol) 
+    : MCExpr(MCExpr::SymbolRef), Symbol(_Symbol) {}
+  
+  MCSymbol *getSymbol() const { return Symbol; }
+
+  static bool classof(const MCExpr *E) { 
+    return E->getKind() == MCExpr::SymbolRef; 
+  }
+  static bool classof(const MCSymbolRefExpr *) { return true; }
+};
+
+/// 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;
+  MCExpr *Expr;
+
+public:
+  MCUnaryExpr(Opcode _Op, MCExpr *_Expr)
+    : MCExpr(MCExpr::Unary), Op(_Op), Expr(_Expr) {}
+  ~MCUnaryExpr() {
+    delete Expr;
+  }
+
+  Opcode getOpcode() const { return Op; }
+
+  MCExpr *getSubExpr() const { return Expr; }
+
+  static bool classof(const MCExpr *E) { 
+    return E->getKind() == MCExpr::Unary; 
+  }
+  static bool classof(const MCUnaryExpr *) { return true; }
+};
+
+/// MCBinaryExpr - Binary assembler expressions.
+class MCBinaryExpr : public MCExpr {
+public:
+  enum Opcode {
+    Add,  ///< Addition.
+    And,  ///< Bitwise and.
+    Div,  ///< Division.
+    EQ,   ///< Equality comparison.
+    GT,   ///< Greater than comparison.
+    GTE,  ///< Greater than or equal comparison.
+    LAnd, ///< Logical and.
+    LOr,  ///< Logical or.
+    LT,   ///< Less than comparison.
+    LTE,  ///< Less than or equal comparison.
+    Mod,  ///< Modulus.
+    Mul,  ///< Multiplication.
+    NE,   ///< Inequality comparison.
+    Or,   ///< Bitwise or.
+    Shl,  ///< Bitwise shift left.
+    Shr,  ///< Bitwise shift right.
+    Sub,  ///< Subtraction.
+    Xor   ///< Bitwise exclusive or.
+  };
+
+private:
+  Opcode Op;
+  MCExpr *LHS, *RHS;
+
+public:
+  MCBinaryExpr(Opcode _Op, MCExpr *_LHS, MCExpr *_RHS)
+    : MCExpr(MCExpr::Binary), Op(_Op), LHS(_LHS), RHS(_RHS) {}
+  ~MCBinaryExpr() {
+    delete LHS;
+    delete RHS;
+  }
+
+  Opcode getOpcode() const { return Op; }
+
+  /// getLHS - Get the left-hand side expression of the binary operator.
+  MCExpr *getLHS() const { return LHS; }
+
+  /// getRHS - Get the right-hand side expression of the binary operator.
+  MCExpr *getRHS() const { return RHS; }
+
+  static bool classof(const MCExpr *E) { 
+    return E->getKind() == MCExpr::Binary; 
+  }
+  static bool classof(const MCBinaryExpr *) { return true; }
+};
+
+} // end namespace llvm
+
+#endif