Difference between revisions of "0051"
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m (Added implementation and linked to gosub) |
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Line 8: | Line 8: | ||
This opcode returns from the current subroutine. | This opcode returns from the current subroutine. | ||
− | When the | + | When the script encounters a [[0051]], it will return from where the last [[0050]] was called. |
The game will crash if: | The game will crash if: |
Latest revision as of 15:07, 1 July 2021
- Description
- Return from the current subroutine.
- Syntax
- 0051: return
- Parameter
- none
This opcode returns from the current subroutine. When the script encounters a 0051, it will return from where the last 0050 was called.
The game will crash if:
Implementation
See gosub for further details.
/* Note: This is not real code and will not compile. */
/* Based on decompilation of SA v2.0 */
/*
The game will crash if the call stack is empty
(i.e. script->callStackPosition == 0), because
script->callStackPosition - 1 would be -1, and
therefore an invalid index.
This can happen if "return" is used outside a
subroutine.
*/
// Move up to the previous stack frame.
script->callStackPosition = script->callStackPosition - 1;
// Set the current offset to the previous one.
// The previous offset will be the offset of the next instruction after the ''gosub''.
script->readPointer = (&script->callStack)[script->callStackPosition];
Keywords
subroutine, gosub, go sub