Lib.Terminator module

MIF08, CAP, CFG library - Terminators.

Each block of a CFG ends with a branching instruction called a terminator. There are three kinds of terminators:

Lib.Statement.AbsoluteJump is a non-conditional jump to another block of the CFG
BranchingTerminator is a conditional branching instruction with two successor blocks. Unlike the class ConditionalJump that was used in LinearCode, both successor labels have to be specified.
Return marks the end of the function

During the construction of the CFG, jump2terminator() builds a terminator for each extracted chunk of instructions.

class Lib.Terminator.Return[source]

Bases: Statement

A terminator that marks the end of the function.

printIns(stream)[source]: Print the statement on the given output. Should never be called on the base class.

targets() → List[Label][source]: Return the labels targetted by the Return terminator.

args() → List[Operand][source]

rename(renamer: Renamer)[source]

substitute(subst: Dict[Operand, Operand])[source]: Return a new instruction, cloned from this one, replacing operands that appear as key in subst by their value.

with_args(new_args: List[Operand])[source]: Return a new instruction, cloned from this one, where operands have been replaced by new_args.

is_read_only() → bool[source]

class Lib.Terminator.BranchingTerminator(cond: Condition, op1: RegisterLike, op2: RegisterLike, label_then: Label, label_else: Label)[source]

Bases: Instruction

A terminating statement with a condition.

cond: Condition: The condition of the branch

label_then: Label: The destination label if the condition is true

label_else: Label: The destination label if the condition is false

op1: RegisterLike: The first operand of the condition

op2: RegisterLike: The second operand of the condition

args() → List[Operand][source]: List of operands the instruction takes

targets() → List[Label][source]: Return the labels targetted by the Branching terminator.

rename(renamer: Renamer)[source]

substitute(subst: Dict[Operand, Operand])[source]: Return a new instruction, cloned from this one, replacing operands that appear as key in subst by their value.

with_args(new_args: List[Operand])[source]: Return a new instruction, cloned from this one, where operands have been replaced by new_args.

Lib.Terminator.Terminator = Lib.Terminator.Return | Lib.Statement.AbsoluteJump | Lib.Terminator.BranchingTerminator: Type alias for terminators

Lib.Terminator.jump2terminator(j: ConditionalJump | AbsoluteJump | None, next_label: Label | None) → Return | AbsoluteJump | BranchingTerminator[source]: Construct the Terminator associated to the potential jump j to the potential label next_label.