78 lines
1.9 KiB
Go
78 lines
1.9 KiB
Go
package commands
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import (
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"fmt"
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"strings"
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"c65gm/internal/compiler"
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"c65gm/internal/preproc"
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"c65gm/internal/utils"
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)
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// DefaultCommand handles DEFAULT statements within SWITCH
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// Syntax: DEFAULT
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type DefaultCommand struct {
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}
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func (c *DefaultCommand) WillHandle(line preproc.Line) bool {
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params, err := utils.ParseParams(line.Text)
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if err != nil || len(params) == 0 {
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return false
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}
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return strings.ToUpper(params[0]) == "DEFAULT"
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}
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func (c *DefaultCommand) Interpret(line preproc.Line, ctx *compiler.CompilerContext) error {
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params, err := utils.ParseParams(line.Text)
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if err != nil {
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return err
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}
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if len(params) != 1 {
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return fmt.Errorf("DEFAULT: expected 1 parameter (DEFAULT), got %d", len(params))
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}
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// Check if we're inside a SWITCH
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if ctx.SwitchStack.IsEmpty() {
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return fmt.Errorf("DEFAULT: not inside a SWITCH statement")
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}
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switchInfo, err := ctx.SwitchStack.Peek()
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if err != nil {
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return fmt.Errorf("DEFAULT: %w", err)
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}
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// Check if DEFAULT has already been seen
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if switchInfo.HasDefault {
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return fmt.Errorf("DEFAULT: multiple DEFAULT statements in same SWITCH")
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}
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return nil
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}
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func (c *DefaultCommand) Generate(ctx *compiler.CompilerContext) ([]string, error) {
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switchInfo, err := ctx.SwitchStack.Peek()
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if err != nil {
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return nil, fmt.Errorf("DEFAULT: %w", err)
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}
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var asm []string
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// If there was a previous CASE, emit implicit break and skip label
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if switchInfo.NeedsPendingCode {
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// Implicit break: jump to end of switch
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asm = append(asm, fmt.Sprintf("\tjmp %s", switchInfo.EndLabel))
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// Emit the pending skip label (where previous case jumps if not matched)
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asm = append(asm, switchInfo.PendingSkipLabel)
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}
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// Mark that we've seen DEFAULT
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switchInfo.HasDefault = true
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// DEFAULT doesn't need a skip label, so clear pending code
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switchInfo.NeedsPendingCode = false
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switchInfo.PendingSkipLabel = ""
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return asm, nil
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}
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