[clang-tidy] Add IgnoredFilesList option to readability-duplicate-include

clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp

@@ -7,10 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "DuplicateIncludeCheck.h"
+#include "../utils/OptionsUtils.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Regex.h"
 #include <memory>
 
 namespace clang::tidy::readability {
@@ -33,10 +35,17 @@ using FileList = SmallVector<StringRef>;
 class DuplicateIncludeCallbacks : public PPCallbacks {
 public:
   DuplicateIncludeCallbacks(DuplicateIncludeCheck &Check,
-                            const SourceManager &SM)
+                            const SourceManager &SM,
+                            const std::vector<StringRef> &IgnoredList)
       : Check(Check), SM(SM) {
     // The main file doesn't participate in the FileChanged notification.
     Files.emplace_back();
+
+    AllowedRegexes.reserve(IgnoredList.size());
+    for (const StringRef &It : IgnoredList) {
+      if (!It.empty())
+        AllowedRegexes.emplace_back(It);
+    }
   }
 
   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
@@ -62,10 +71,32 @@ class DuplicateIncludeCallbacks : public PPCallbacks {
   SmallVector<FileList> Files;
   DuplicateIncludeCheck &Check;
   const SourceManager &SM;
+  std::vector<llvm::Regex> AllowedRegexes;
+
+  bool isAllowedDuplicate(StringRef FileName, OptionalFileEntryRef File) const {
+    if (llvm::any_of(AllowedRegexes,
+                     [&](const llvm::Regex &R) { return R.match(FileName); }))
+      return true;
+
+    if (File) {
+      const StringRef Resolved = File->getName();
+      if (llvm::any_of(AllowedRegexes,
+                       [&](const llvm::Regex &R) { return R.match(Resolved); }))
+        return true;
+    }
+
+    return false;
+  }
 };
 
 } // namespace
 
+DuplicateIncludeCheck::DuplicateIncludeCheck(StringRef Name,
+                                             ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      IgnoredFilesList(utils::options::parseStringList(
+          Options.get("IgnoredFilesList", ""))) {}
+
 void DuplicateIncludeCallbacks::FileChanged(SourceLocation Loc,
                                             FileChangeReason Reason,
                                             SrcMgr::CharacteristicKind FileType,
@@ -86,6 +117,9 @@ void DuplicateIncludeCallbacks::InclusionDirective(
       FilenameRange.getEnd().isMacroID())
     return;
   if (llvm::is_contained(Files.back(), FileName)) {
+    if (isAllowedDuplicate(FileName, File)) {
+      return;
+    }
     // We want to delete the entire line, so make sure that [Start,End] covers
     // everything.
     const SourceLocation Start =
@@ -111,7 +145,13 @@ void DuplicateIncludeCallbacks::MacroUndefined(const Token &MacroNameTok,
 
 void DuplicateIncludeCheck::registerPPCallbacks(
     const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
-  PP->addPPCallbacks(std::make_unique<DuplicateIncludeCallbacks>(*this, SM));
+  PP->addPPCallbacks(
+      std::make_unique<DuplicateIncludeCallbacks>(*this, SM, IgnoredFilesList));
+}
+
+void DuplicateIncludeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "IgnoredFilesList",
+                utils::options::serializeStringList(IgnoredFilesList));
 }
 
 } // namespace clang::tidy::readability

clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.h

@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DUPLICATEINCLUDECHECK_H
 
 #include "../ClangTidyCheck.h"
+#include <vector>
 
 namespace clang::tidy::readability {
 
@@ -19,11 +20,16 @@ namespace clang::tidy::readability {
 /// directives between them are analyzed.
 class DuplicateIncludeCheck : public ClangTidyCheck {
 public:
-  DuplicateIncludeCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
+  DuplicateIncludeCheck(StringRef Name, ClangTidyContext *Context);
 
   void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
                            Preprocessor *ModuleExpanderPP) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+private:
+  // Semicolon-separated list of regexes or file names to ignore from duplicate
+  // warnings.
+  const std::vector<StringRef> IgnoredFilesList;
 };
 
 } // namespace clang::tidy::readability

clang-tools-extra/docs/ReleaseNotes.rst

@@ -316,7 +316,7 @@ Changes in existing checks
   exceptions from captures are now diagnosed, exceptions in the bodies of
   lambdas that aren't actually invoked are not. Additionally, fixed an issue
   where the check wouldn't diagnose throws in arguments to functions or
-  constructors. Added fine-grained configuration via options 
+  constructors. Added fine-grained configuration via options
   `CheckDestructors`, `CheckMoveMemberFunctions`, `CheckMain`,
   `CheckedSwapFunctions`, and `CheckNothrowFunctions`.
 
@@ -505,6 +505,11 @@ Changes in existing checks
   ignoring default constructors with user provided arguments and adding
   detection in container's method except ``empty``.
 
+- Improved :doc:`readability-duplicate-include
+  <clang-tidy/checks/readability/duplicate-include>` check by adding
+  the ``IgnoredFilesList`` option (semicolon-separated list of regexes or
+  filenames) to allow intentional duplicates.
+
 - Improved :doc:`readability-identifier-naming
   <clang-tidy/checks/readability/identifier-naming>` check by ignoring
   declarations and macros in system headers. The documentation is also improved

clang-tools-extra/docs/clang-tidy/checks/readability/duplicate-include.rst

@@ -7,6 +7,17 @@ Looks for duplicate includes and removes them.  The check maintains a list of
 included files and looks for duplicates.  If a macro is defined or undefined
 then the list of included files is cleared.
 
+Options
+-------
+
+.. option:: IgnoredFilesList
+
+  A semicolon-separated list of regular expressions or filenames that are
+  allowed to be included multiple times without diagnostics. Matching is
+  performed against the textual include name. If the header can be
+  resolved, its full path is also matched against the patterns.
+  Default is empty.
+
 Examples:
 
 .. code-block:: c++

clang-tools-extra/test/clang-tidy/checkers/readability/Inputs/duplicate-include/pack_begin.h

@@ -0,0 +1 @@
+// Intentionally unguarded begin-pack header used in tests

clang-tools-extra/test/clang-tidy/checkers/readability/Inputs/duplicate-include/pack_end.h

@@ -0,0 +1 @@
+// Intentionally unguarded end-pack header used in tests

clang-tools-extra/test/clang-tidy/checkers/readability/duplicate-include-ignored-files.cpp

@@ -0,0 +1,9 @@
+// RUN: %check_clang_tidy %s readability-duplicate-include %t -- \
+// RUN:   -config="{CheckOptions: {readability-duplicate-include.IgnoredFilesList: 'pack_.*\\.h'}}" \
+// RUN:   -- -I %S/Inputs/duplicate-include
+
+#include "pack_begin.h"
+struct A { int x; };
+#include "pack_end.h"
+
+// no warning