| // Copyright 2020 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package build |
| |
| import ( |
| "encoding/json" |
| "errors" |
| "fmt" |
| "os" |
| ) |
| |
| var ( |
| // ErrArgNotSet represents an arg not having been set in the build. |
| ErrArgNotSet = errors.New("arg not set") |
| ) |
| |
| // Args represents the GN arguments set in the build. |
| type Args map[string]json.RawMessage |
| |
| // BoolValue returns the value of a boolean GN arg set in the build. If unset, |
| // ErrArgNotSet will be returned. |
| func (args Args) BoolValue(name string) (bool, error) { |
| msg, ok := args[name] |
| if !ok { |
| return false, ErrArgNotSet |
| } |
| var val bool |
| err := json.Unmarshal(msg, &val) |
| return val, err |
| } |
| |
| // TODO(you): extend to different types as needed. |
| |
| func loadArgs(manifest string) (Args, error) { |
| f, err := os.Open(manifest) |
| if err != nil { |
| return nil, fmt.Errorf("failed to open %s: %w", manifest, err) |
| } |
| defer f.Close() |
| var args Args |
| if err := json.NewDecoder(f).Decode(&args); err != nil { |
| return nil, fmt.Errorf("failed to decode %s: %w", manifest, err) |
| } |
| return args, nil |
| } |