5.4.2.12 GoTo Statement

Note

This section describes the implementation of MS-VBAL §5.4.2.12 GoTo Statement.

Syntax

AST node	Instruction kind	Notes
GoToStatementNode	`Jump`	Instruction`.Target` holds the offset of the target label.

A GoTo statement's target is an expression naming or numbering a label or line. There is no static link between the GoToStatementNode and the LineLabelNode or LineNumberNode it targets (RD-VBAL §3.4.2 Simple Statements).

A bare line-number target in a single-line If branch (If x Then 100) is not modelled as its own shape. The parser synthesizes a GoToStatementNode as that branch's statement, typically its only one (RD-VBAL §5.4.2.9 Single-line If Statement).

GoTo lowers to the InstructionKind Jump (RD-VBAL §3.5.2 Instruction).

Static Semantics

Lowering resolves the target label to an offset (RD-VBAL §3.5.3 Lowering Block Statements). A label is scoped to the whole procedure, so a GoTo from anywhere in the procedure into the middle of a loop body or an If body resolves in the same way as any other jump (RD-VBAL §5.4.1.1 Statement Labels).

Condition	Result
The procedure defines the target label.	`Target` is the label's offset.
The procedure does not define the target label, e.g. `GoTo Done` with no `Done:` line.	`Target` is `null`, and lowering reports VBC09309 Label not defined.

Runtime Semantics

The executor dispatches a Jump instruction as an unconditional GoTo: execution branches to Instruction.Target, the offset of the target label.
A label with no statement after it, including the end-label of the lexically enclosing procedure declaration, resolves to the offset right past the last instruction. A branch to it completes the activation as if execution had reached the end of the procedure body (RD-VBAL §3.5.1 InstructionList).

An instruction's EnclosingWith is computed once, at lowering time; it is not tracked as a runtime stack the interpreter pushes and pops. A GoTo into or out of a With block therefore leaves no stale state to unwind (RD-VBAL §5.4.2.21 With Statement).

A GoTo that lands directly on the Next of a For or For Each loop whose opener has not run in the activation raises run-time error 92, "For loop not initialized"; see RD-VBAL §5.4.2.3 For Statement and RD-VBAL §5.4.2.4 For Each Statement.

Implementation

RDCore.Runtime.Execution.ProcedureExecutor dispatches Jump instructions (RD-VBAL §3.5.4 Execution).
InstructionListLowering resolves the target label into Instruction.Target.