blob: ef6b315e9f80081a365cd6354fb42653f3398ba2 [file] [log] [blame]
// Copyright 2020 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package config
import (
"fmt"
"strings"
"android/soong/android"
)
// Overarching principles for Rust lints on Android:
// The Android build system tries to avoid reporting warnings during the build.
// Therefore, by default, we upgrade warnings to denials. For some of these
// lints, an allow exception is setup, using the variables below.
//
// The lints are split into two categories. The first one contains the built-in
// lints (https://doc.rust-lang.org/rustc/lints/index.html). The second is
// specific to Clippy lints (https://rust-lang.github.io/rust-clippy/master/).
//
// For both categories, there are 3 levels of linting possible:
// - "android", for the strictest lints that applies to all Android platform code.
// - "vendor", for relaxed rules.
// - "none", to disable the linting.
// There is a fourth option ("default") which automatically selects the linting level
// based on the module's location. See defaultLintSetForPath.
//
// When developing a module, you may set `lints = "none"` and `clippy_lints =
// "none"` to disable all the linting. Expect some questioning during code review
// if you enable one of these options.
var (
// Default Rust lints that applies to Google-authored modules.
defaultRustcLints = []string{
"-A deprecated",
"-D missing-docs",
"-D warnings",
}
// Default Clippy lints. These are applied on top of defaultRustcLints.
// It should be assumed that any warning lint will be promoted to a
// deny.
defaultClippyLints = []string{
"-A clippy::type-complexity",
"-A clippy::unnecessary-wraps",
"-A clippy::unusual-byte-groupings",
"-A clippy::upper-case-acronyms",
}
// Rust lints for vendor code.
defaultRustcVendorLints = []string{
"-A deprecated",
"-D warnings",
}
// Clippy lints for vendor source. These are applied on top of
// defaultRustcVendorLints. It should be assumed that any warning lint
// will be promoted to a deny.
defaultClippyVendorLints = []string{
"-A clippy::complexity",
"-A clippy::perf",
"-A clippy::style",
}
// For prebuilts/ and external/, no linting is expected. If a warning
// or a deny is reported, it should be fixed upstream.
allowAllLints = []string{
"--cap-lints allow",
}
)
func init() {
// Default Rust lints. These apply to all Google-authored modules.
pctx.VariableFunc("RustDefaultLints", func(ctx android.PackageVarContext) string {
if override := ctx.Config().Getenv("RUST_DEFAULT_LINTS"); override != "" {
return override
}
return strings.Join(defaultRustcLints, " ")
})
pctx.VariableFunc("ClippyDefaultLints", func(ctx android.PackageVarContext) string {
if override := ctx.Config().Getenv("CLIPPY_DEFAULT_LINTS"); override != "" {
return override
}
return strings.Join(defaultClippyLints, " ")
})
// Rust lints that only applies to external code.
pctx.VariableFunc("RustVendorLints", func(ctx android.PackageVarContext) string {
if override := ctx.Config().Getenv("RUST_VENDOR_LINTS"); override != "" {
return override
}
return strings.Join(defaultRustcVendorLints, " ")
})
pctx.VariableFunc("ClippyVendorLints", func(ctx android.PackageVarContext) string {
if override := ctx.Config().Getenv("CLIPPY_VENDOR_LINTS"); override != "" {
return override
}
return strings.Join(defaultClippyVendorLints, " ")
})
pctx.StaticVariable("RustAllowAllLints", strings.Join(allowAllLints, " "))
}
const noLint = ""
const rustcDefault = "${config.RustDefaultLints}"
const rustcVendor = "${config.RustVendorLints}"
const rustcAllowAll = "${config.RustAllowAllLints}"
const clippyDefault = "${config.ClippyDefaultLints}"
const clippyVendor = "${config.ClippyVendorLints}"
// lintConfig defines a set of lints and clippy configuration.
type lintConfig struct {
rustcConfig string // for the lints to apply to rustc.
clippyEnabled bool // to indicate if clippy should be executed.
clippyConfig string // for the lints to apply to clippy.
}
const (
androidLints = "android"
vendorLints = "vendor"
noneLints = "none"
)
// lintSets defines the categories of linting for Android and their mapping to lintConfigs.
var lintSets = map[string]lintConfig{
androidLints: {rustcDefault, true, clippyDefault},
vendorLints: {rustcVendor, true, clippyVendor},
noneLints: {rustcAllowAll, false, noLint},
}
type pathLintSet struct {
prefix string
set string
}
// This is a map of local path prefixes to a lint set. The first entry
// matching will be used. If no entry matches, androidLints ("android") will be
// used.
var defaultLintSetForPath = []pathLintSet{
{"external", noneLints},
{"hardware", vendorLints},
{"prebuilts", noneLints},
{"vendor/google", androidLints},
{"vendor", vendorLints},
}
// ClippyLintsForDir returns a boolean if Clippy should be executed and if so, the lints to be used.
func ClippyLintsForDir(dir string, clippyLintsProperty *string) (bool, string, error) {
if clippyLintsProperty != nil {
set, ok := lintSets[*clippyLintsProperty]
if ok {
return set.clippyEnabled, set.clippyConfig, nil
}
if *clippyLintsProperty != "default" {
return false, "", fmt.Errorf("unknown value for `clippy_lints`: %v, valid options are: default, android, vendor or none", *clippyLintsProperty)
}
}
for _, p := range defaultLintSetForPath {
if strings.HasPrefix(dir, p.prefix) {
setConfig := lintSets[p.set]
return setConfig.clippyEnabled, setConfig.clippyConfig, nil
}
}
return true, clippyDefault, nil
}
// RustcLintsForDir returns the standard lints to be used for a repository.
func RustcLintsForDir(dir string, lintProperty *string) (string, error) {
if lintProperty != nil {
set, ok := lintSets[*lintProperty]
if ok {
return set.rustcConfig, nil
}
if *lintProperty != "default" {
return "", fmt.Errorf("unknown value for `lints`: %v, valid options are: default, android, vendor or none", *lintProperty)
}
}
for _, p := range defaultLintSetForPath {
if strings.HasPrefix(dir, p.prefix) {
return lintSets[p.set].rustcConfig, nil
}
}
return rustcDefault, nil
}