Function collectDecls

scripts/metricsdocgen/scanner/scanner.go:324–367

collectDecls collects const and var declarations from a file. This is used to resolve constant and variable references in metric definitions.

(file *ast.File)

// collectDecls collects const and var declarations from a file.
// This is used to resolve constant and variable references in metric definitions.
func collectDecls(file *ast.File) declarations {
	decls := declarations{
		strings:      make(map[string]string),
		stringSlices: make(map[string][]string),
	}

	for _, decl := range file.Decls {
		genDecl, ok := decl.(*ast.GenDecl)
		if !ok {
			continue
		}

		for _, spec := range genDecl.Specs {
			valueSpec, ok := spec.(*ast.ValueSpec)
			if !ok {
				continue
			}

			for i, name := range valueSpec.Names {
				if i >= len(valueSpec.Values) {
					continue
				}

				switch v := valueSpec.Values[i].(type) {
				case *ast.BasicLit:
					// String literal: const name = "value"
					decls.strings[name.Name] = strings.Trim(v.Value, `"`)
				case *ast.BinaryExpr:
					// Concatenation: const name = prefix + "suffix"
					if resolved := resolveBinaryExpr(v, decls); resolved != "" {
						decls.strings[name.Name] = resolved
					}
				case *ast.CompositeLit:
					// Slice literal: var labels = []string{"a", "b"}
					if resolved := extractStringSlice(v, decls); resolved != nil {
						decls.stringSlices[name.Name] = resolved
					}
				}
			}
		}
	}

	return decls
}

// extractLabels extracts label names from an expression passed as an argument
// to a metric constructor. Handles both inline []string literals and