Function extractLabels

scripts/metricsdocgen/scanner/scanner.go:375–388

extractLabels extracts label names from an expression passed as an argument to a metric constructor. Handles both inline []string literals and variable references from decls. Examples: - []string{"label1", "label2"}: ["label1", "label2"] (inline literal) - myLabels: resolved value of myLabels variab

(expr ast.Expr, decls declarations)

//   - []string{"label1", "label2"}: ["label1", "label2"] (inline literal)
//   - myLabels: resolved value of myLabels variable (variable reference)
func extractLabels(expr ast.Expr, decls declarations) []string {
	switch e := expr.(type) {
	case *ast.CompositeLit:
		// []string{"label1", "label2"}
		return extractStringSlice(e, decls)
	case *ast.Ident:
		// Variable reference like 'labels'.
		if labels, ok := decls.stringSlices[e.Name]; ok {
			return labels
		}
		return nil
	}
	return nil
}

// extractNewDescMetric extracts a metric from a prometheus.NewDesc() call.
// Pattern: prometheus.NewDesc(name, help, variableLabels, constLabels)