Theory JVMInstructions

(*  Title:      JinjaThreads/JVM/JVMInstructions.thy
    Author:     Gerwin Klein, Andreas Lochbihler

section ‹Instructions of the JVM›

theory JVMInstructions

datatype 'addr instr 
  = Load nat                  ― ‹load from local variable›
  | Store nat                 ― ‹store into local variable›
  | Push "'addr val"          ― ‹push a value (constant)›
  | New cname                 ― ‹create object›
  | NewArray ty               ― ‹create array for elements of given type›
  | ALoad                     ― ‹Load array element from heap to stack›
  | AStore                    ― ‹Set element in array›
  | ALength                   ― ‹Return the length of the array›
  | Getfield vname cname      ― ‹Fetch field from object›
  | Putfield vname cname      ― ‹Set field in object›
  | CAS vname cname           ― ‹Compare-and-swap instruction›
  | Checkcast ty              ― ‹Check whether object is of given type›
  | Instanceof ty             ― ‹instanceof test›
  | Invoke mname nat          ― ‹inv. instance meth of an object›
  | Return                    ― ‹return from method›
  | Pop                       ― ‹pop top element from opstack›
  | Dup                       ― ‹duplicate top stack element›
  | Swap                      ― ‹swap top stack elements›
  | BinOpInstr bop            ― ‹binary operator instruction›
  | Goto int                  ― ‹goto relative address›
  | IfFalse int               ― ‹branch if top of stack false›
  | ThrowExc                  ― ‹throw top of stack as exception›
  | MEnter                    ― ‹enter the monitor of object on top of the stack›
  | MExit                     ― ‹exit the monitor of object on top of the stack›

abbreviation CmpEq :: "'addr instr"
where "CmpEq  BinOpInstr Eq"

abbreviation CmpLeq :: "'addr instr"
where "CmpLeq  BinOpInstr LessOrEqual"

abbreviation CmpGeq :: "'addr instr"
where "CmpGeq  BinOpInstr GreaterOrEqual"

abbreviation CmpLt :: "'addr instr"
where "CmpLt  BinOpInstr LessThan"

abbreviation CmpGt :: "'addr instr"
where "CmpGt  BinOpInstr GreaterThan"

abbreviation IAdd :: "'addr instr"
where "IAdd  BinOpInstr Add"

abbreviation ISub :: "'addr instr"
where "ISub  BinOpInstr Subtract"

abbreviation IMult :: "'addr instr"
where "IMult  BinOpInstr Mult"

abbreviation IDiv :: "'addr instr"
where "IDiv  BinOpInstr Div"

abbreviation IMod :: "'addr instr"
where "IMod  BinOpInstr Mod"

abbreviation IShl :: "'addr instr"
where "IShl  BinOpInstr ShiftLeft"

abbreviation IShr :: "'addr instr"
where "IShr  BinOpInstr ShiftRightSigned"

abbreviation IUShr :: "'addr instr"
where "IUShr  BinOpInstr ShiftRightZeros"

abbreviation IAnd :: "'addr instr"
where "IAnd  BinOpInstr BinAnd"

abbreviation IOr :: "'addr instr"
where "IOr  BinOpInstr BinOr"

abbreviation IXor :: "'addr instr"
where "IXor  BinOpInstr BinXor"

  'addr bytecode = "'addr instr list"

  ex_entry = "pc × pc × cname option × pc × nat" 
  ― ‹start-pc, end-pc, exception type (None = Any), handler-pc, remaining stack depth›

  ex_table = "ex_entry list"

  'addr jvm_method = "nat × nat × 'addr bytecode × ex_table"
   ― ‹max stacksize›
   ― ‹number of local variables. Add 1 + no. of parameters to get no. of registers›
   ― ‹instruction sequence›
   ― ‹exception handler table›

  'addr jvm_prog = "'addr jvm_method prog"