1// Copyright 2016 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package config
16
17import (
18	"android/soong/android"
19	"strings"
20)
21
22var (
23	// Some clang-tidy checks have bugs or don't work for Android.
24	// They are disabled here, overriding any locally selected checks.
25	globalNoCheckList = []string{
26		// https://b.corp.google.com/issues/153464409
27		// many local projects enable cert-* checks, which
28		// trigger bugprone-reserved-identifier.
29		"-bugprone-reserved-identifier*,-cert-dcl51-cpp,-cert-dcl37-c",
30		// http://b/153757728
31		"-readability-qualified-auto",
32		// http://b/193716442
33		"-bugprone-implicit-widening-of-multiplication-result",
34		// Too many existing functions trigger this rule, and fixing it requires large code
35		// refactoring. The cost of maintaining this tidy rule outweighs the benefit it brings.
36		"-bugprone-easily-swappable-parameters",
37		// http://b/216364337 - TODO: Follow-up after compiler update to
38		// disable or fix individual instances.
39		"-cert-err33-c",
40		// http://b/241125373
41		"-bugprone-unchecked-optional-access",
42		// http://b/265438407
43		"-misc-use-anonymous-namespace",
44		// http://b/285005947
45		"-performance-avoid-endl",
46	}
47
48	// Some clang-tidy checks are included in some tidy_checks_as_errors lists,
49	// but not all warnings are fixed/suppressed yet. These checks are not
50	// disabled in the TidyGlobalNoChecks list, so we can see them and fix/suppress them.
51	globalNoErrorCheckList = []string{
52		// http://b/241997913
53		"-bugprone-assignment-in-if-condition",
54		// http://b/155034972
55		"-bugprone-branch-clone",
56		// http://b/155034563
57		"-bugprone-signed-char-misuse",
58		// http://b/241819232
59		"-misc-const-correctness",
60		// http://b/285356805
61		"-bugprone-unsafe-functions",
62		"-cert-msc24-c",
63		"-cert-msc33-c",
64		// http://b/285356799
65		"-modernize-type-traits",
66		// http://b/285361108
67		"-readability-avoid-unconditional-preprocessor-if",
68	}
69
70	extraArgFlags = []string{
71		// We might be using the static analyzer through clang tidy.
72		// https://bugs.llvm.org/show_bug.cgi?id=32914
73		"-D__clang_analyzer__",
74
75		// A recent change in clang-tidy (r328258) enabled destructor inlining, which
76		// appears to cause a number of false positives. Until that's resolved, this turns
77		// off the effects of r328258.
78		// https://bugs.llvm.org/show_bug.cgi?id=37459
79		"-Xclang",
80		"-analyzer-config",
81		"-Xclang",
82		"c++-temp-dtor-inlining=false",
83	}
84)
85
86func init() {
87	// The global default tidy checks should include clang-tidy
88	// default checks and tested groups, but exclude known noisy checks.
89	// See https://clang.llvm.org/extra/clang-tidy/checks/list.html
90	pctx.VariableConfigMethod("TidyDefaultGlobalChecks", func(config android.Config) string {
91		if override := config.Getenv("DEFAULT_GLOBAL_TIDY_CHECKS"); override != "" {
92			return override
93		}
94		checks := strings.Join([]string{
95			"android-*",
96			"bugprone-*",
97			"cert-*",
98			"clang-diagnostic-unused-command-line-argument",
99			// Select only google-* checks that do not have thousands of warnings.
100			// Add more such checks when we clean up source code.
101			// "google-build-using-namespace",
102			// "google-default-arguments",
103			// "google-explicit-constructor",
104			// "google-global-names-in-headers",
105			// "google-runtime-int",
106			"google-build-explicit-make-pair",
107			"google-build-namespaces",
108			"google-runtime-operator",
109			"google-upgrade-*",
110			"misc-*",
111			"performance-*",
112			"portability-*",
113			"-bugprone-assignment-in-if-condition",
114			"-bugprone-easily-swappable-parameters",
115			"-bugprone-narrowing-conversions",
116			"-misc-const-correctness",
117			"-misc-no-recursion",
118			"-misc-non-private-member-variables-in-classes",
119			"-misc-unused-parameters",
120			"-performance-no-int-to-ptr",
121			// the following groups are not in clang-tidy default checks.
122			// -altera-*
123			// -cppcoreguidelines-*
124			// -darwin-*
125			// -fuchsia-*
126			// -hicpp-*
127			// -llvm-*
128			// -llvmlibc-*
129			// -modernize-*
130			// -mpi-*
131			// -objc-*
132			// -readability-*
133			// -zircon-*
134		}, ",")
135		// clang-analyzer-* checks are slow for large files, but we have TIDY_TIMEOUT to
136		// limit clang-tidy runtime. We allow clang-tidy default clang-analyzer-* checks,
137		// and add it explicitly when CLANG_ANALYZER_CHECKS is set.
138		// The insecureAPI.DeprecatedOrUnsafeBufferHandling warning does not apply to Android.
139		if config.IsEnvTrue("CLANG_ANALYZER_CHECKS") {
140			checks += ",clang-analyzer-*,-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling"
141		} else {
142			checks += ",-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling"
143		}
144		return checks
145	})
146
147	// The external and vendor projects do not run clang-tidy unless TIDY_EXTERNAL_VENDOR is set.
148	// We do not add "-*" to the check list to avoid suppressing the check list in .clang-tidy config files.
149	// There are too many clang-tidy warnings in external and vendor projects, so we only
150	// enable some google checks for these projects. Users can add more checks locally with the
151	// "tidy_checks" list in .bp files, or the "Checks" list in .clang-tidy config files.
152	pctx.VariableConfigMethod("TidyExternalVendorChecks", func(config android.Config) string {
153		if override := config.Getenv("DEFAULT_EXTERNAL_VENDOR_TIDY_CHECKS"); override != "" {
154			return override
155		}
156		return strings.Join([]string{
157			"clang-diagnostic-unused-command-line-argument",
158			"google-build-explicit-make-pair",
159			"google-build-namespaces",
160			"google-runtime-operator",
161			"google-upgrade-*",
162			"-clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling",
163		}, ",")
164	})
165
166	pctx.StaticVariable("TidyGlobalNoChecks", strings.Join(globalNoCheckList, ","))
167
168	pctx.StaticVariable("TidyGlobalNoErrorChecks", strings.Join(globalNoErrorCheckList, ","))
169
170	pctx.StaticVariable("TidyExtraArgFlags", strings.Join(extraArgFlags, " "))
171
172	// To reduce duplicate warnings from the same header files,
173	// header-filter will contain only the module directory and
174	// those specified by DEFAULT_TIDY_HEADER_DIRS.
175	pctx.VariableConfigMethod("TidyDefaultHeaderDirs", func(config android.Config) string {
176		return config.Getenv("DEFAULT_TIDY_HEADER_DIRS")
177	})
178
179	// Use WTIH_TIDY_FLAGS to pass extra global default clang-tidy flags.
180	pctx.VariableConfigMethod("TidyWithTidyFlags", func(config android.Config) string {
181		return config.Getenv("WITH_TIDY_FLAGS")
182	})
183}
184
185type PathBasedTidyCheck struct {
186	PathPrefix string
187	Checks     string
188}
189
190const tidyDefault = "${config.TidyDefaultGlobalChecks}"
191const tidyExternalVendor = "${config.TidyExternalVendorChecks}"
192const tidyDefaultNoAnalyzer = "${config.TidyDefaultGlobalChecks},-clang-analyzer-*"
193
194// This is a map of local path prefixes to the set of default clang-tidy checks
195// to be used.  This is like android.IsThirdPartyPath, but with more patterns.
196// The last matched local_path_prefix should be the most specific to be used.
197var DefaultLocalTidyChecks = []PathBasedTidyCheck{
198	{"external/", tidyExternalVendor},
199	{"frameworks/compile/mclinker/", tidyExternalVendor},
200	{"hardware/", tidyExternalVendor},
201	{"hardware/google/", tidyDefault},
202	{"hardware/interfaces/", tidyDefault},
203	{"hardware/ril/", tidyDefault},
204	{"hardware/libhardware", tidyDefault}, // all 'hardware/libhardware*'
205	{"vendor/", tidyExternalVendor},
206	{"vendor/google", tidyDefault}, // all 'vendor/google*'
207	{"vendor/google/external/", tidyExternalVendor},
208	{"vendor/google_arc/libs/org.chromium.arc.mojom", tidyExternalVendor},
209	{"vendor/google_devices/", tidyExternalVendor}, // many have vendor code
210}
211
212var reversedDefaultLocalTidyChecks = reverseTidyChecks(DefaultLocalTidyChecks)
213
214func reverseTidyChecks(in []PathBasedTidyCheck) []PathBasedTidyCheck {
215	ret := make([]PathBasedTidyCheck, len(in))
216	for i, check := range in {
217		ret[len(in)-i-1] = check
218	}
219	return ret
220}
221
222func TidyChecksForDir(dir string) string {
223	dir = dir + "/"
224	for _, pathCheck := range reversedDefaultLocalTidyChecks {
225		if strings.HasPrefix(dir, pathCheck.PathPrefix) {
226			return pathCheck.Checks
227		}
228	}
229	return tidyDefault
230}
231
232func neverTidyForDir(dir string) bool {
233	// This function can be extended if tidy needs to be disabled for more directories.
234	return strings.HasPrefix(dir, "external/grpc-grpc")
235}
236
237func NoClangTidyForDir(allowExternalVendor bool, dir string) bool {
238	// Tidy can be disable for a module in dir, if the dir is "neverTidyForDir",
239	// or if it belongs to external|vendor and !allowExternalVendor.
240	// This function depends on TidyChecksForDir, which selects tidyExternalVendor
241	// checks for external/vendor projects.
242	return neverTidyForDir(dir) ||
243		(!allowExternalVendor && TidyChecksForDir(dir) == tidyExternalVendor)
244}
245
246// Returns a globally disabled tidy checks, overriding locally selected checks.
247func TidyGlobalNoChecks() string {
248	if len(globalNoCheckList) > 0 {
249		return ",${config.TidyGlobalNoChecks}"
250	}
251	return ""
252}
253
254// Returns a globally allowed/no-error tidy checks, appended to -warnings-as-errors.
255func TidyGlobalNoErrorChecks() string {
256	if len(globalNoErrorCheckList) > 0 {
257		return ",${config.TidyGlobalNoErrorChecks}"
258	}
259	return ""
260}
261
262func TidyExtraArgFlags() []string {
263	return extraArgFlags
264}
265
266func TidyFlagsForSrcFile(srcFile android.Path, flags string) string {
267	// Disable clang-analyzer-* checks globally for generated source files
268	// because some of them are too huge. Local .bp files can add wanted
269	// clang-analyzer checks through the tidy_checks property.
270	// Need to do this patch per source file, because some modules
271	// have both generated and organic source files.
272	if _, ok := srcFile.(android.WritablePath); ok {
273		if strings.Contains(flags, tidyDefault) {
274			return strings.ReplaceAll(flags, tidyDefault, tidyDefaultNoAnalyzer)
275		}
276	}
277	return flags
278}
279