Theory JVMState

theory JVMState
imports Conform
(*  Title:      HOL/MicroJava/JVM/JVMState.thy
Author: Cornelia Pusch, Gerwin Klein, Technische Universitaet Muenchen
*)


header {*
\chapter{Java Virtual Machine}\label{cha:jvm}
\isaheader{State of the JVM}
*}


theory JVMState
imports "../J/Conform"
begin

section {* Frame Stack *}
type_synonym opstack = "val list"
type_synonym locvars = "val list"
type_synonym p_count = nat

type_synonym
frame = "opstack ×
locvars ×
cname ×
sig ×
p_count"


-- "operand stack"
-- "local variables (including this pointer and method parameters)"
-- "name of class where current method is defined"
-- "method name + parameter types"
-- "program counter within frame"


section {* Exceptions *}
definition raise_system_xcpt :: "bool => xcpt => val option" where
"raise_system_xcpt b x ≡ raise_if b x None"

section {* Runtime State *}
type_synonym
jvm_state = "val option × aheap × frame list" -- "exception flag, heap, frames"


section {* Lemmas *}

lemma new_Addr_OutOfMemory:
"snd (new_Addr hp) = Some xcp ==> xcp = Addr (XcptRef OutOfMemory)"
proof -
obtain ref xp where "new_Addr hp = (ref, xp)" by (cases "new_Addr hp")
moreover
assume "snd (new_Addr hp) = Some xcp"
ultimately
show ?thesis by (auto dest: new_AddrD)
qed

end