clang tidy: add header ignore option to include duplicate files

clang-tools-extra/clang-tidy/misc/HeaderIncludeCycleCheck.cpp

@@ -107,7 +107,7 @@ class CyclicDependencyCallbacks : public PPCallbacks {
       Check.diag(Loc, "direct self-inclusion of header file '%0'") << FileName;
       return;
     }
-
+    
     Check.diag(Loc, "circular header file dependency detected while including "
                     "'%0', please check the include path")
         << FileName;

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

@@ -7,11 +7,16 @@
 //===----------------------------------------------------------------------===//
 
 #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/ADT/StringExtras.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Regex.h"
 #include <memory>
+#include <vector>
 
 namespace clang::tidy::readability {
 
@@ -33,11 +38,8 @@ using FileList = SmallVector<StringRef>;
 class DuplicateIncludeCallbacks : public PPCallbacks {
 public:
   DuplicateIncludeCallbacks(DuplicateIncludeCheck &Check,
-                            const SourceManager &SM)
-      : Check(Check), SM(SM) {
-    // The main file doesn't participate in the FileChanged notification.
-    Files.emplace_back();
-  }
+                            const SourceManager &SM,
+                            const std::vector<std::string> &AllowedStrings);
 
   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                    SrcMgr::CharacteristicKind FileType,
@@ -62,10 +64,25 @@ class DuplicateIncludeCallbacks : public PPCallbacks {
   SmallVector<FileList> Files;
   DuplicateIncludeCheck &Check;
   const SourceManager &SM;
+  std::vector<llvm::Regex> AllowedDuplicateRegex;
+
+  bool IsAllowedDuplicateInclude(StringRef TokenName);
 };
 
 } // namespace
 
+DuplicateIncludeCallbacks::DuplicateIncludeCallbacks(
+    DuplicateIncludeCheck &Check, const SourceManager &SM,
+    const std::vector<std::string> &AllowedStrings)
+    : Check(Check), SM(SM) {
+  // The main file doesn't participate in the FileChanged notification.
+  Files.emplace_back();
+  AllowedDuplicateRegex.reserve(AllowedStrings.size());
+  for (const std::string &str : AllowedStrings) {
+    AllowedDuplicateRegex.emplace_back(str);
+  }
+}
+
 void DuplicateIncludeCallbacks::FileChanged(SourceLocation Loc,
                                             FileChangeReason Reason,
                                             SrcMgr::CharacteristicKind FileType,
@@ -85,6 +102,13 @@ void DuplicateIncludeCallbacks::InclusionDirective(
   if (FilenameRange.getBegin().isMacroID() ||
       FilenameRange.getEnd().isMacroID())
     return;
+
+  // if duplicate allowed, record and return
+  if (IsAllowedDuplicateInclude(FileName)) {
+    Files.back().push_back(FileName);
+    return;
+  }
+
   if (llvm::is_contained(Files.back(), FileName)) {
     // We want to delete the entire line, so make sure that [Start,End] covers
     // everything.
@@ -109,9 +133,41 @@ void DuplicateIncludeCallbacks::MacroUndefined(const Token &MacroNameTok,
   Files.back().clear();
 }
 
+bool DuplicateIncludeCallbacks::IsAllowedDuplicateInclude(StringRef FileName) {
+  // try to match with each regex
+  for (const llvm::Regex &reg : AllowedDuplicateRegex) {
+    if (reg.match(FileName))
+      return true;
+  }
+  return false;
+}
+} // namespace clang::tidy::readability
+
+namespace clang::tidy::readability {
+DuplicateIncludeCheck::DuplicateIncludeCheck(StringRef Name,
+                                             ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+  std::string Raw = Options.get("IgnoreHeaders", "").str();
+  if (!Raw.empty()) {
+    SmallVector<StringRef, 4> StringParts;
+    StringRef(Raw).split(StringParts, ';', -1, false);
+
+    for (StringRef Part : StringParts) {
+      Part = Part.trim();
+      if (!Part.empty())
+        AllowedDuplicateIncludes.push_back(Part.str());
+    }
+  }
+}
+
 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, AllowedDuplicateIncludes));
 }
 
+void DuplicateIncludeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "IgnoreHeaders",
+                llvm::join(AllowedDuplicateIncludes, ";"));
+}
 } // namespace clang::tidy::readability

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

@@ -10,7 +10,8 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DUPLICATEINCLUDECHECK_H
 
 #include "../ClangTidyCheck.h"
-
+#include <string>
+#include <vector>
 namespace clang::tidy::readability {
 
 /// \brief Find and remove duplicate #include directives.
@@ -19,11 +20,15 @@ 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:
+  std::vector<std::string> AllowedDuplicateIncludes;
 };
 
 } // namespace clang::tidy::readability

clang-tools-extra/docs/ReleaseNotes.rst

@@ -487,6 +487,10 @@ Changes in existing checks
   <clang-tidy/checks/readability/uppercase-literal-suffix>` check to recognize
   literal suffixes added in C++23 and C23.
 
+- Improved :doc:`readability-duplicate-include
+  <clang-tidy/checks/readability/duplicate-include>` check by introducing the
+  ``AllowedDuplicateIncludes`` option, which exempts specified headers from
+  duplicate include warnings.
 - Improved :doc:`readability-use-concise-preprocessor-directives
   <clang-tidy/checks/readability/use-concise-preprocessor-directives>` check to
   generate correct fix-its for forms without a space after the directive.

clang-tools-extra/docs/clang-tidy/checks/misc/include-cleaner.rst

@@ -28,7 +28,7 @@ Options
 -------
 
 .. option:: IgnoreHeaders
-
+   
    A semicolon-separated list of regexes to disable insertion/removal of header
    files that match this regex as a suffix.  E.g., `foo/.*` disables
    insertion/removal for all headers under the directory `foo`. Default is an

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

@@ -10,7 +10,7 @@ then the list of included files is cleared.
 Examples:
 
 .. code-block:: c++
-
+  
   #include <memory>
   #include <vector>
   #include <memory>
@@ -33,3 +33,13 @@ Because of the intervening macro definitions, this code remains unchanged:
   #define NDEBUG
   #include "assertion.h"
   // ...code with assertions disabled
+
+Options
+-------
+
+.. option:: IgnoreHeaders
+
+   A semicolon-separated list of regexes to allow duplicate inclusion of header
+   files that match this regex.  E.g., `foo/.*` disables
+   insertion/removal for all headers under the directory `foo`. Default is an
+   empty string, no headers will be ignored.

clang-tools-extra/docs/clang-tidy/checks/readability/else-after-return.rst

@@ -63,7 +63,6 @@ Options
 -------
 
 .. option:: WarnOnUnfixable
-
    When `true`, emit a warning for cases where the check can't output a
    Fix-It. These can occur with declarations inside the ``else`` branch that
    would have an extended lifetime if the ``else`` branch was removed.

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

@@ -0,0 +1,2 @@
+// dummy other.h (should warn on duplicate includes)
+#pragma once

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

@@ -0,0 +1,2 @@
+// dummy pack_begin.h (allowed duplicate)
+#pragma once

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

@@ -0,0 +1,2 @@
+// dummy pack_end.h (allowed duplicate)
+#pragma once

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

@@ -0,0 +1,19 @@
+// RUN: %check_clang_tidy %s readability-duplicate-include %t -- \
+// RUN:   -header-filter='' \
+// RUN:   -config='{CheckOptions: [{key: readability-duplicate-include.IgnoreHeaders, value: "pack_begin.h;pack_end.h"}]}' \
+// RUN:   -- -I %S/Inputs/duplicate-include-allowed
+//
+// This test lives in test/clang-tidy/checkers/
+// Inputs for allowed duplicate includes are in test/clang-tidy/checkers/Inputs/duplicate-include-allowed
+
+#include "pack_begin.h"
+#include "pack_begin.h" 
+// No warning expected
+
+#include "other.h"
+#include "other.h" 
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: duplicate include [readability-duplicate-include]
+
+#include "pack_end.h"
+#include "pack_end.h" 
+// No warning expected