Change the behavior of clang-tidy -checks=, remove -disable-checks.

[alexfh]

Summary

Make checks filtering more intuitive and easy to use. Remove
-disable-checks and change the format of -checks= to a comma-separated list of
globs with optional '-' prefix to denote exclusion. The -checks= option is now
cumulative, so it modifies defaults, not overrides them. Each glob adds or
removes to the current set of checks, so the filter can be refined or overriden
by adding globs.

Example:

The default value for -checks= is
'*,-clang-analyzer-alpha*,-llvm-include-order,-llvm-namespace-comment,-google-*',
which allows all checks except for the ones named clang-analyzer-alpha* and
others specified with the leading '-'. To allow all google-* checks one can
write:
  clang-tidy -checks=google-* ...
If one needs only google-* checks, we first need to remove everything (-*):
  clang-tidy -checks=-*,google-*
etc.

I'm not sure if we need to change something here, so I didn't touch the docs
yet.

[klimek]

After thinking a bit about this, I'd like to revisit this from scratch (as
it has changed quite a bit).

Why is: -check=<regexp> not enough? Give it a good enough default value
(that is printed if you say -help), and we have the following use cases:

• add something to the default set: clang-tidy -help, copy default set, add

own

• run only a single check: -check=my-full.check
• run only google checks: -check=google-.*

[alexfh]

Manuel tells offline that the patch is fine.

clang-tidy/ClangTidyDiagnosticConsumer.h

struct ClangTidyError {
   ClangTidyMessage Message;
   tooling::Replacements Fix;
   SmallVector<ClangTidyMessage, 1> Notes;
 };
 
 /// \brief Filters checks by name.
 class ChecksFilter {
 public:
-  ChecksFilter(const ClangTidyOptions& Options);
-  bool isCheckEnabled(StringRef Name);
+  // GlobList is a comma-separated list of globs (only '*' metacharacter is
+  // supported) with optional '-' prefix to denote exclusion.
+  ChecksFilter(StringRef GlobList);
+  // Returns true if the check with the specified Name should be enabled.
+  // The result is the last matching glob's Positive flag. If Name is not
+  // matched by any globs, the check is not enabled.
+  bool isCheckEnabled(StringRef Name) { return isCheckEnabled(Name, false); }
 
 private:
-  llvm::Regex EnableChecks;
-  llvm::Regex DisableChecks;
+  bool isCheckEnabled(StringRef Name, bool Enabled);
+
+  bool Positive;
+  llvm::Regex Regex;
+  std::unique_ptr<ChecksFilter> NextFilter;
 };
 
 struct ClangTidyStats {
   ClangTidyStats()
       : ErrorsDisplayed(0), ErrorsIgnoredCheckFilter(0), ErrorsIgnoredNOLINT(0),
         ErrorsIgnoredNonUserCode(0) {}
 
   unsigned ErrorsDisplayed;

clang-tidy/ClangTidyDiagnosticConsumer.cpp

ClangTidyMessage::ClangTidyMessage(StringRef Message,
     : Message(Message) {
   assert(Loc.isValid() && Loc.isFileID());
   FilePath = Sources.getFilename(Loc);
   FileOffset = Sources.getFileOffset(Loc);
 }
 
 ClangTidyError::ClangTidyError(StringRef CheckName) : CheckName(CheckName) {}
 
-ChecksFilter::ChecksFilter(const ClangTidyOptions &Options)
-    : EnableChecks(Options.EnableChecksRegex),
-      DisableChecks(Options.DisableChecksRegex) {}
-
-bool ChecksFilter::isCheckEnabled(StringRef Name) {
-  return EnableChecks.match(Name) && !DisableChecks.match(Name);
+// Returns true if GlobList starts with the negative indicator ('-'), removes it
+// from the GlobList.
+static bool ConsumeNegativeIndicator(StringRef &GlobList) {
+  if (GlobList.startswith("-")) {
+    GlobList = GlobList.substr(1);
+    return true;
+  }
+  return false;
+}
+// Converts first glob from the comma-separated list of globs to Regex and
+// removes it and the trailing comma from the GlobList.
+static llvm::Regex ConsumeGlob(StringRef &GlobList) {
+  StringRef Glob = GlobList.substr(0, GlobList.find(','));
+  GlobList = GlobList.substr(Glob.size() + 1);
+  llvm::SmallString<128> RegexText("^");
+  StringRef MetaChars("()^$|*+?.[]\\{}");
+  for (char C : Glob) {
+    if (C == '*')
+      RegexText.push_back('.');
+    else if (MetaChars.find(C))
+      RegexText.push_back('\\');
+    RegexText.push_back(C);
+  }
+  RegexText.push_back('$');
+  return llvm::Regex(RegexText);
+}
+
+ChecksFilter::ChecksFilter(StringRef GlobList)
+    : Positive(!ConsumeNegativeIndicator(GlobList)),
+      Regex(ConsumeGlob(GlobList)),
+      NextFilter(GlobList.empty() ? nullptr : new ChecksFilter(GlobList)) {}
+
+bool ChecksFilter::isCheckEnabled(StringRef Name, bool Enabled) {
+  if (Regex.match(Name))
+    Enabled = Positive;
+
+  if (NextFilter)
+    Enabled = NextFilter->isCheckEnabled(Name, Enabled);
+  return Enabled;
 }
 
 ClangTidyContext::ClangTidyContext(const ClangTidyOptions &Options)
-    : DiagEngine(nullptr), Options(Options), Filter(Options) {}
+    : DiagEngine(nullptr), Options(Options), Filter(Options.Checks) {}
 
 DiagnosticBuilder ClangTidyContext::diag(
     StringRef CheckName, SourceLocation Loc, StringRef Description,
     DiagnosticIDs::Level Level /* = DiagnosticIDs::Warning*/) {
   assert(Loc.isValid());
   bool Invalid;
   const char *CharacterData =
       DiagEngine->getSourceManager().getCharacterData(Loc, &Invalid);

clang-tidy/ClangTidyOptions.h

 
 #include <string>
 
 namespace clang {
 namespace tidy {
 
 /// \brief Contains options for clang-tidy.
 struct ClangTidyOptions {
-  ClangTidyOptions() : EnableChecksRegex(".*"), AnalyzeTemporaryDtors(false) {}
-  std::string EnableChecksRegex;
-  std::string DisableChecksRegex;
+  ClangTidyOptions() : Checks("*"), AnalyzeTemporaryDtors(false) {}
+  std::string Checks;
   // Output warnings from headers matching this filter. Warnings from main files
   // will always be displayed.
   std::string HeaderFilterRegex;
   bool AnalyzeTemporaryDtors;
 };
 
 } // end namespace tidy
 } // end namespace clang
 
 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANG_TIDY_OPTIONS_H

clang-tidy/tool/ClangTidyMain.cpp

 using namespace clang::driver;
 using namespace clang::tooling;
 using namespace llvm;
 
 static cl::OptionCategory ClangTidyCategory("clang-tidy options");
 
 static cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
 
-static cl::opt<std::string> Checks(
-    "checks",
-    cl::desc("Regular expression matching the names of the checks to be run."),
-    cl::init(".*"), cl::cat(ClangTidyCategory));
-static cl::opt<std::string> DisableChecks(
-    "disable-checks",
-    cl::desc("Regular expression matching the names of the checks to disable."),
-    cl::init("(clang-analyzer-alpha.*" // Too many false positives.
-             "|llvm-include-order"     // Not implemented yet.
-             "|llvm-namespace-comment" // Not complete.
-             "|google-.*)"),           // Doesn't apply to LLVM.
-    cl::cat(ClangTidyCategory));
+const char DefaultChecks[] =
+    "*,"                       // Enable all checks, except these:
+    "-clang-analyzer-alpha*,"  // Too many false positives.
+    "-llvm-include-order,"     // Not implemented yet.
+    "-llvm-namespace-comment," // Not complete.
+    "-google-*,";              // Doesn't apply to LLVM.
+static cl::opt<std::string>
+Checks("checks",
+       cl::desc("Comma-separated list of positive and negative globs matching\n"
+                "the names of the checks to be run."),
+       cl::init(""), cl::cat(ClangTidyCategory));
 static cl::opt<std::string> HeaderFilter(
     "header-filter",
     cl::desc("Regular expression matching the names of the headers to output\n"
              "diagnostics from. Diagnostics from the main file of each\n"
              "translation unit are always displayed."),
     cl::init(""), cl::cat(ClangTidyCategory));
 static cl::opt<bool> Fix("fix", cl::desc("Fix detected errors if possible."),
                          cl::init(false), cl::cat(ClangTidyCategory));
if (Stats.ErrorsIgnoredNonUserCode)
                       "non-system headers.\n";
   }
 }
 
 int main(int argc, const char **argv) {
   CommonOptionsParser OptionsParser(argc, argv, ClangTidyCategory);
 
   clang::tidy::ClangTidyOptions Options;
-  Options.EnableChecksRegex = Checks;
-  Options.DisableChecksRegex = DisableChecks;
+  Options.Checks = DefaultChecks + Checks;
   Options.HeaderFilterRegex = HeaderFilter;
   Options.AnalyzeTemporaryDtors = AnalyzeTemporaryDtors;
 
   // FIXME: Allow using --list-checks without positional arguments.
   if (ListChecks) {
     llvm::outs() << "Enabled checks:";
     for (auto CheckName : clang::tidy::getCheckNames(Options))
       llvm::outs() << "\n    " << CheckName;

test/clang-tidy/arg-comments.cpp

-// RUN: clang-tidy --checks=misc-argument-comment %s -- | FileCheck %s
+// RUN: clang-tidy --checks='-*,misc-argument-comment' %s -- | FileCheck %s
 
 // FIXME: clang-tidy should provide a -verify mode to make writing these checks
 // easier and more accurate.
 
 // CHECK-NOT: warning
 
 void f(int x, int y);
 

test/clang-tidy/basic.cpp

 // RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
-// RUN: clang-tidy %t.cpp -checks='llvm-namespace-comment' -disable-checks='' -- > %t2.cpp
+// RUN: clang-tidy %t.cpp -checks='-*,llvm-namespace-comment' -- > %t2.cpp
 // RUN: FileCheck -input-file=%t2.cpp %s
 
 namespace i {
 }
 // CHECK: warning: namespace not terminated with a closing comment [llvm-namespace-comment]

test/clang-tidy/check_clang_tidy_fix.sh

 #!/bin/sh
 #
 # Run clang-tidy in fix mode and verify the result.
 
 INPUT_FILE=$1
 CHECK_TO_RUN=$2
 TEMPORARY_FILE=$3.cpp
 
 grep -Ev "// *[A-Z-]+:" ${INPUT_FILE} > ${TEMPORARY_FILE}
-clang-tidy ${TEMPORARY_FILE} -fix --checks=${CHECK_TO_RUN} \
-    --disable-checks="" -- --std=c++11
+clang-tidy ${TEMPORARY_FILE} -fix --checks="-*,${CHECK_TO_RUN}" -- --std=c++11
 FileCheck -input-file=${TEMPORARY_FILE} ${INPUT_FILE}

test/clang-tidy/check_clang_tidy_output.sh

 #!/bin/sh
 #
 # Run clang-tidy and verify its command line output.
 
 INPUT_FILE=$1
 CHECK_TO_RUN=$2
 
-clang-tidy --checks=${CHECK_TO_RUN} --disable-checks="" ${INPUT_FILE} \
-    -- --std=c++11 -x c++ \
+clang-tidy --checks="-*,${CHECK_TO_RUN}" ${INPUT_FILE} -- --std=c++11 -x c++ \
   | FileCheck ${INPUT_FILE}

test/clang-tidy/deduplication.cpp

-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' %s -- | FileCheck %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' %s -- | FileCheck %s
 
 template<typename T>
 class A { A(T); };
 // CHECK: :[[@LINE-1]]:11: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 // CHECK-NOT: warning:
 
 
 void f() {
   A<int> a;
   A<double> b;
 }

test/clang-tidy/diagnostic.cpp

-// RUN: clang-tidy -disable-checks='' %s.nonexistent.cpp -- | FileCheck -check-prefix=CHECK1 %s
-// RUN: clang-tidy -disable-checks='' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK2 %s
-// RUN: clang-tidy -checks='(google-explicit-constructor|clang-diagnostic-literal-conversion)' -disable-checks='' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK3 %s
-// RUN: clang-tidy -checks='clang-diagnostic-macro-redefined' -disable-checks='' %s -- -DMACRO_FROM_COMMAND_LINE | FileCheck -check-prefix=CHECK4 %s
+// RUN: clang-tidy %s.nonexistent.cpp -- | FileCheck -check-prefix=CHECK1 %s
+// RUN: clang-tidy -checks='google-explicit-constructor' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK2 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor,clang-diagnostic-literal-conversion' %s -- -fan-unknown-option | FileCheck -check-prefix=CHECK3 %s
+// RUN: clang-tidy -checks='-*,clang-diagnostic-macro-redefined' %s -- -DMACRO_FROM_COMMAND_LINE | FileCheck -check-prefix=CHECK4 %s
 
 // CHECK1-NOT: warning
 // CHECK2-NOT: warning
 // CHECK3-NOT: warning
 
 // CHECK1: warning: error reading '{{.*}}.nonexistent.cpp'
 // CHECK2: warning: unknown argument: '-fan-unknown-option'
 

test/clang-tidy/file-filter.cpp

-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' -header-filter='' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck %s
-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' -header-filter='.*' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck --check-prefix=CHECK2 %s
-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' -header-filter='header2\.h' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck --check-prefix=CHECK3 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='.*' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck --check-prefix=CHECK2 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header2\.h' %s -- -I %S/Inputs/file-filter 2>&1 | FileCheck --check-prefix=CHECK3 %s
 
 #include "header1.h"
 // CHECK-NOT: warning:
 // CHECK2: header1.h:1:12: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 // CHECK3-NOT: warning:
 
 #include "header2.h"
 // CHECK-NOT: warning:

test/clang-tidy/fix.cpp

 // RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
-// RUN: clang-tidy %t.cpp -checks='(google-explicit-constructor|llvm-namespace-comment)' -disable-checks='' -fix -- > %t.msg 2>&1
+// RUN: clang-tidy %t.cpp -checks='-*,google-explicit-constructor,llvm-namespace-comment' -fix -- > %t.msg 2>&1
 // RUN: FileCheck -input-file=%t.cpp %s
 // RUN: FileCheck -input-file=%t.msg -check-prefix=CHECK-MESSAGES %s
 
 namespace i {
 }
 // CHECK: } // namespace i
 // CHECK-MESSAGES: note: FIX-IT applied suggested code changes
 
 class A { A(int i); };
 // CHECK: class A { explicit A(int i); };
 // CHECK-MESSAGES: note: FIX-IT applied suggested code changes
 // CHECK-MESSAGES: clang-tidy applied 2 of 2 suggested fixes.

test/clang-tidy/macros.cpp

-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' %s -- | FileCheck %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' %s -- | FileCheck %s
 
 #define Q(name) class name { name(int i); }
 
 Q(A);
 // CHECK: :[[@LINE-1]]:3: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 // CHECK: :3:30: note: expanded from macro 'Q'

test/clang-tidy/nolint.cpp

-// RUN: clang-tidy -checks=google-explicit-constructor -disable-checks='' %s -- 2>&1 | FileCheck %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' %s -- 2>&1 | FileCheck %s
 
 class A { A(int i); };
 // CHECK: :[[@LINE-1]]:11: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 
 class B { B(int i); }; // NOLINT
 // CHECK-NOT: :[[@LINE-1]]:11: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 
 class C { C(int i); }; // NOLINT(we-dont-care-about-categories-yet)
 // CHECK-NOT: :[[@LINE-1]]:11: warning: Single-argument constructors must be explicit [google-explicit-constructor]
 // CHECK: Suppressed 2 warnings (2 NOLINT)

test/clang-tidy/select-checks.cpp

 // RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
-// RUN: clang-tidy %t.cpp -fix -checks=^llvm-.* -disable-checks='' --
+// RUN: clang-tidy %t.cpp -fix -checks='-*,llvm-*' --
 // RUN: FileCheck -input-file=%t.cpp %s
 
 namespace i {
 }
 // CHECK: } // namespace i
 
 class A { A(int i); }; // Not fixing this, because the check is in google-.
 // CHECK: class A { A(int i); };

test/clang-tidy/static-analyzer.cpp

-// RUN: clang-tidy %s -checks='clang-analyzer-.*' -disable-checks='alpha' -- | FileCheck %s
+// RUN: clang-tidy %s -checks='-*,clang-analyzer-*,-clang-analyzer-alpha*' -- | FileCheck %s
 extern void *malloc(unsigned long);
 extern void free(void *);
 
 void f() {
   int *p = new int(42);
   delete p;
   delete p;
   // CHECK: warning: Attempt to free released memory [clang-analyzer-cplusplus.NewDelete]
 }
 
 void g() {
   void *q = malloc(132);
   free(q);
   free(q);
   // CHECK: warning: Attempt to free released memory [clang-analyzer-unix.Malloc]
 }

test/clang-tidy/temporaries.cpp

-// RUN: clang-tidy -checks=clang-analyzer-core.NullDereference -disable-checks='' -analyze-temporary-dtors %s -- | FileCheck %s
+// RUN: clang-tidy -checks='-*,clang-analyzer-core.NullDereference' -analyze-temporary-dtors %s -- | FileCheck %s
 
 struct NoReturnDtor {
   ~NoReturnDtor() __attribute__((noreturn));
 };
 
 extern bool check(const NoReturnDtor &);
 
 // CHECK-NOT: warning

unittests/clang-tidy/ClangTidyDiagnosticConsumerTest.cpp

TEST(ClangTidyDiagnosticConsumer, SortsErrors) {
   std::vector<ClangTidyError> Errors;
   runCheckOnCode<TestCheck>("int a;", &Errors);
   EXPECT_EQ(2ul, Errors.size());
   // FIXME: Remove " []" once the check name is removed from the message text.
   EXPECT_EQ("type specifier []", Errors[0].Message.Message);
   EXPECT_EQ("variable []", Errors[1].Message.Message);
 }
 
+TEST(ChecksFilter, Empty) {
+  ChecksFilter Filter("");
+
+  EXPECT_TRUE(Filter.isCheckEnabled(""));
+  EXPECT_FALSE(Filter.isCheckEnabled("aaa"));
+}
+
+TEST(ChecksFilter, Nothing) {
+  ChecksFilter Filter("-*");
+
+  EXPECT_FALSE(Filter.isCheckEnabled(""));
+  EXPECT_FALSE(Filter.isCheckEnabled("a"));
+  EXPECT_FALSE(Filter.isCheckEnabled("-*"));
+  EXPECT_FALSE(Filter.isCheckEnabled("-"));
+  EXPECT_FALSE(Filter.isCheckEnabled("*"));
+}
+
+TEST(ChecksFilter, Everything) {
+  ChecksFilter Filter("*");
+
+  EXPECT_TRUE(Filter.isCheckEnabled(""));
+  EXPECT_TRUE(Filter.isCheckEnabled("aaaa"));
+  EXPECT_TRUE(Filter.isCheckEnabled("-*"));
+  EXPECT_TRUE(Filter.isCheckEnabled("-"));
+  EXPECT_TRUE(Filter.isCheckEnabled("*"));
+}
+
+TEST(ChecksFilter, Simple) {
+  ChecksFilter Filter("aaa");
+
+  EXPECT_TRUE(Filter.isCheckEnabled("aaa"));
+  EXPECT_FALSE(Filter.isCheckEnabled(""));
+  EXPECT_FALSE(Filter.isCheckEnabled("aa"));
+  EXPECT_FALSE(Filter.isCheckEnabled("aaaa"));
+  EXPECT_FALSE(Filter.isCheckEnabled("bbb"));
+}
+
+TEST(ChecksFilter, Complex) {
+  ChecksFilter Filter("*,-a.*,-b.*,a.a.*,-a.a.a.*,-..,-...,-..+,-*$,-*qwe*");
+
+  EXPECT_TRUE(Filter.isCheckEnabled("aaa"));
+  EXPECT_TRUE(Filter.isCheckEnabled("qqq"));
+  EXPECT_FALSE(Filter.isCheckEnabled("a."));
+  EXPECT_FALSE(Filter.isCheckEnabled("a.b"));
+  EXPECT_FALSE(Filter.isCheckEnabled("b."));
+  EXPECT_FALSE(Filter.isCheckEnabled("b.b"));
+  EXPECT_TRUE(Filter.isCheckEnabled("a.a.b"));
+  EXPECT_FALSE(Filter.isCheckEnabled("a.a.a.a"));
+  EXPECT_FALSE(Filter.isCheckEnabled("qwe"));
+  EXPECT_FALSE(Filter.isCheckEnabled("asdfqweasdf"));
+  EXPECT_TRUE(Filter.isCheckEnabled("asdfqwEasdf"));
+}
+
 } // namespace test
 } // namespace tidy
 } // namespace clang