Commit d2e8fb33 authored by Richard's avatar Richard
Browse files

[clang-tidy] Add readability-duplicate-include check

Looks for duplicate includes and removes them.

Every time an include directive is processed, check a vector of filenames
to see if the included file has already been included.  If so, it issues
a warning and a replacement to remove the entire line containing the
duplicated include directive.

When a macro is defined or undefined, the vector of filenames is cleared.
This enables including the same file multiple times, but getting
different expansions based on the set of active macros at the time of
inclusion.  For example:

  #undef NDEBUG
  #include "assertion.h"
  // ...code with assertions enabled

  #define NDEBUG
  #include "assertion.h"
  // ...code with assertions disabled

Since macros are redefined between the inclusion of assertion.h,
they are not flagged as redundant.

Differential Revision: https://reviews.llvm.org/D7982
parent 2e26633a
......@@ -11,6 +11,7 @@ add_clang_library(clangTidyReadabilityModule
ContainerSizeEmptyCheck.cpp
ConvertMemberFunctionsToStatic.cpp
DeleteNullPointerCheck.cpp
DuplicateIncludeCheck.cpp
ElseAfterReturnCheck.cpp
FunctionCognitiveComplexityCheck.cpp
FunctionSizeCheck.cpp
......
//===--- DuplicateIncludeCheck.cpp - clang-tidy ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "DuplicateIncludeCheck.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include <memory>
namespace clang {
namespace tidy {
namespace readability {
static SourceLocation advanceBeyondCurrentLine(const SourceManager &SM,
SourceLocation Start,
int Offset) {
const FileID Id = SM.getFileID(Start);
const unsigned LineNumber = SM.getSpellingLineNumber(Start);
while (SM.getFileID(Start) == Id &&
SM.getSpellingLineNumber(Start.getLocWithOffset(Offset)) == LineNumber)
Start = Start.getLocWithOffset(Offset);
return Start;
}
namespace {
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();
}
void FileChanged(SourceLocation Loc, FileChangeReason Reason,
SrcMgr::CharacteristicKind FileType,
FileID PrevFID) override;
void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
StringRef FileName, bool IsAngled,
CharSourceRange FilenameRange, const FileEntry *File,
StringRef SearchPath, StringRef RelativePath,
const Module *Imported,
SrcMgr::CharacteristicKind FileType) override;
void MacroDefined(const Token &MacroNameTok,
const MacroDirective *MD) override;
void MacroUndefined(const Token &MacroNameTok, const MacroDefinition &MD,
const MacroDirective *Undef) override;
private:
// A list of included files is kept for each file we enter.
SmallVector<FileList> Files;
DuplicateIncludeCheck &Check;
const SourceManager &SM;
};
void DuplicateIncludeCallbacks::FileChanged(SourceLocation Loc,
FileChangeReason Reason,
SrcMgr::CharacteristicKind FileType,
FileID PrevFID) {
if (Reason == EnterFile)
Files.emplace_back();
else
Files.pop_back();
}
void DuplicateIncludeCallbacks::InclusionDirective(
SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
StringRef SearchPath, StringRef RelativePath, const Module *Imported,
SrcMgr::CharacteristicKind FileType) {
if (llvm::find(Files.back(), FileName) != Files.back().end()) {
// We want to delete the entire line, so make sure that [Start,End] covers
// everything.
SourceLocation Start =
advanceBeyondCurrentLine(SM, HashLoc, -1).getLocWithOffset(-1);
SourceLocation End =
advanceBeyondCurrentLine(SM, FilenameRange.getEnd(), 1);
Check.diag(HashLoc, "duplicate include")
<< FixItHint::CreateRemoval(SourceRange{Start, End});
} else
Files.back().push_back(FileName);
}
void DuplicateIncludeCallbacks::MacroDefined(const Token &MacroNameTok,
const MacroDirective *MD) {
Files.back().clear();
}
void DuplicateIncludeCallbacks::MacroUndefined(const Token &MacroNameTok,
const MacroDefinition &MD,
const MacroDirective *Undef) {
Files.back().clear();
}
} // namespace
void DuplicateIncludeCheck::registerPPCallbacks(
const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
PP->addPPCallbacks(std::make_unique<DuplicateIncludeCallbacks>(*this, SM));
}
} // namespace readability
} // namespace tidy
} // namespace clang
//===--- DuplicateIncludeCheck.h - clang-tidy -------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DUPLICATE_INCLUDE_CHECK_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DUPLICATE_INCLUDE_CHECK_H
#include "../ClangTidyCheck.h"
namespace clang {
namespace tidy {
namespace readability {
/// \brief Find and remove duplicate #include directives.
///
/// Only consecutive include directives without any other preprocessor
/// directives between them are analyzed.
class DuplicateIncludeCheck : public ClangTidyCheck {
public:
DuplicateIncludeCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context) {}
void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
Preprocessor *ModuleExpanderPP) override;
};
} // namespace readability
} // namespace tidy
} // namespace clang
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DUPLICATE_INCLUDE_CHECK_H
......@@ -16,6 +16,7 @@
#include "ContainerSizeEmptyCheck.h"
#include "ConvertMemberFunctionsToStatic.h"
#include "DeleteNullPointerCheck.h"
#include "DuplicateIncludeCheck.h"
#include "ElseAfterReturnCheck.h"
#include "FunctionCognitiveComplexityCheck.h"
#include "FunctionSizeCheck.h"
......@@ -71,6 +72,8 @@ public:
"readability-convert-member-functions-to-static");
CheckFactories.registerCheck<DeleteNullPointerCheck>(
"readability-delete-null-pointer");
CheckFactories.registerCheck<DuplicateIncludeCheck>(
"readability-duplicate-include");
CheckFactories.registerCheck<ElseAfterReturnCheck>(
"readability-else-after-return");
CheckFactories.registerCheck<FunctionCognitiveComplexityCheck>(
......
......@@ -124,6 +124,11 @@ New checks
Finds cases where code could use ``data()`` rather than the address of the
element at index 0 in a container.
- New :doc:`readability-duplicate-include
<clang-tidy/checks/readability-duplicate-include>` check.
Looks for duplicate includes and removes them.
- New :doc:`readability-identifier-length
<clang-tidy/checks/readability-identifier-length>` check.
......
......@@ -294,6 +294,7 @@ Clang-Tidy Checks
`readability-container-size-empty <readability-container-size-empty.html>`_, "Yes"
`readability-convert-member-functions-to-static <readability-convert-member-functions-to-static.html>`_, "Yes"
`readability-delete-null-pointer <readability-delete-null-pointer.html>`_, "Yes"
`readability-duplicate-include <readability-duplicate-include.html>`_, "Yes"
`readability-else-after-return <readability-else-after-return.html>`_, "Yes"
`readability-function-cognitive-complexity <readability-function-cognitive-complexity.html>`_,
`readability-function-size <readability-function-size.html>`_,
......
.. title:: clang-tidy - readability-duplicate-include
readability-duplicate-include
=============================
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.
Examples:
.. code-block:: c++
#include <memory>
#include <vector>
#include <memory>
becomes
.. code-block:: c++
#include <memory>
#include <vector>
Because of the intervening macro definitions, this code remains unchanged:
.. code-block:: c++
#undef NDEBUG
#include "assertion.h"
// ...code with assertions enabled
#define NDEBUG
#include "assertion.h"
// ...code with assertions disabled
#ifndef READABILITY_DUPLICATE_INCLUDE_H
#define READABILITY_DUPLICATE_INCLUDE_H
extern int g;
#include "readability-duplicate-include2.h"
extern int h;
#include "readability-duplicate-include2.h"
extern int i;
// CHECK-MESSAGES: :[[@LINE-2]]:1: warning: duplicate include
// CHECK-FIXES: {{^extern int g;$}}
// CHECK-FIXES-NEXT: {{^#include "readability-duplicate-include2.h"$}}
// CHECK-FIXES-NEXT: {{^extern int h;$}}
// CHECK-FIXES-NEXT: {{^extern int i;$}}
#endif
// RUN: %check_clang_tidy %s readability-duplicate-include %t -- -- -isystem %S/Inputs/readability-duplicate-include/system -I %S/Inputs/readability-duplicate-include
int a;
#include <string.h>
int b;
#include <string.h>
int c;
// CHECK-MESSAGES: :[[@LINE-2]]:1: warning: duplicate include [readability-duplicate-include]
// CHECK-FIXES: {{^int a;$}}
// CHECK-FIXES-NEXT: {{^#include <string.h>$}}
// CHECK-FIXES-NEXT: {{^int b;$}}
// CHECK-FIXES-NEXT: {{^int c;$}}
int d;
#include <iostream>
int e;
#include <iostream> // extra stuff that will also be removed
int f;
// CHECK-MESSAGES: :[[@LINE-2]]:1: warning: duplicate include
// CHECK-FIXES: {{^int d;$}}
// CHECK-FIXES-NEXT: {{^#include <iostream>$}}
// CHECK-FIXES-NEXT: {{^int e;$}}
// CHECK-FIXES-NEXT: {{^int f;$}}
int g;
#include "readability-duplicate-include.h"
int h;
#include "readability-duplicate-include.h"
int i;
// CHECK-MESSAGES: :[[@LINE-2]]:1: warning: duplicate include
// CHECK-FIXES: {{^int g;$}}
// CHECK-FIXES-NEXT: {{^#include "readability-duplicate-include.h"$}}
// CHECK-FIXES-NEXT: {{^int h;$}}
// CHECK-FIXES-NEXT: {{^int i;$}}
#include <types.h>
int j;
#include <sys/types.h>
int k;
#include <sys/types.h>
int l;
// CHECK-MESSAGES: :[[@LINE-2]]:1: warning: duplicate include
// CHECK-FIXES: {{^int j;$}}
// CHECK-FIXES-NEXT: {{^#include <sys/types.h>$}}
// CHECK-FIXES-NEXT: {{^int k;$}}
// CHECK-FIXES-NEXT: {{^int l;$}}
int m;
# include <string.h> // lots of space
int n;
// CHECK-MESSAGES: :[[@LINE-2]]:9: warning: duplicate include
// CHECK-FIXES: {{^int m;$}}
// CHECK-FIXES-NEXT: {{^int n;$}}
// defining a macro in the main file resets the included file cache
#define ARBITRARY_MACRO
int o;
#include <sys/types.h>
int p;
// CHECK-FIXES: {{^int o;$}}
// CHECK-FIXES-NEXT: {{^#include <sys/types.h>$}}
// CHECK-FIXES-NEXT: {{^int p;$}}
// undefining a macro resets the cache
#undef ARBITRARY_MACRO
int q;
#include <sys/types.h>
int r;
// CHECK-FIXES: {{^int q;$}}
// CHECK-FIXES-NEXT: {{^#include <sys/types.h>$}}
// CHECK-FIXES-NEXT: {{^int r;$}}
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