[clang-tools-extra] r281206 - [clang-tidy] readability-misplaced-array-index: add new check that warns when array index is misplaced.
Daniel Marjamaki via cfe-commits
cfe-commits at lists.llvm.org
Mon Sep 12 05:04:14 PDT 2016
Author: danielmarjamaki
Date: Mon Sep 12 07:04:13 2016
New Revision: 281206
URL: http://llvm.org/viewvc/llvm-project?rev=281206&view=rev
Log:
[clang-tidy] readability-misplaced-array-index: add new check that warns when array index is misplaced.
Reviewers: alexfh
Differential Revision: https://reviews.llvm.org/D21134
Added:
clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.cpp
clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.h
clang-tools-extra/trunk/docs/clang-tidy/checks/readability-misplaced-array-index.rst
clang-tools-extra/trunk/test/clang-tidy/readability-misplaced-array-index.cpp
Modified:
clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt
clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp
clang-tools-extra/trunk/docs/ReleaseNotes.rst
clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
Modified: clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt?rev=281206&r1=281205&r2=281206&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt Mon Sep 12 07:04:13 2016
@@ -10,6 +10,7 @@ add_clang_library(clangTidyReadabilityMo
IdentifierNamingCheck.cpp
ImplicitBoolCastCheck.cpp
InconsistentDeclarationParameterNameCheck.cpp
+ MisplacedArrayIndexCheck.cpp
NamedParameterCheck.cpp
NamespaceCommentCheck.cpp
NonConstParameterCheck.cpp
Added: clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.cpp?rev=281206&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.cpp Mon Sep 12 07:04:13 2016
@@ -0,0 +1,57 @@
+//===--- MisplacedArrayIndexCheck.cpp - clang-tidy-------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MisplacedArrayIndexCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/FixIt.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+void MisplacedArrayIndexCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(arraySubscriptExpr(hasLHS(hasType(isInteger())),
+ hasRHS(hasType(isAnyPointer())))
+ .bind("expr"),
+ this);
+}
+
+void MisplacedArrayIndexCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *ArraySubscriptE =
+ Result.Nodes.getNodeAs<ArraySubscriptExpr>("expr");
+
+ auto Diag = diag(ArraySubscriptE->getLocStart(), "confusing array subscript "
+ "expression, usually the "
+ "index is inside the []");
+
+ // Only try to fixit when LHS and RHS can be swapped directly without changing
+ // the logic.
+ const Expr *RHSE = ArraySubscriptE->getRHS()->IgnoreParenImpCasts();
+ if (!isa<StringLiteral>(RHSE) && !isa<DeclRefExpr>(RHSE) &&
+ !isa<MemberExpr>(RHSE))
+ return;
+
+ const StringRef LText = tooling::fixit::getText(
+ ArraySubscriptE->getLHS()->getSourceRange(), *Result.Context);
+ const StringRef RText = tooling::fixit::getText(
+ ArraySubscriptE->getRHS()->getSourceRange(), *Result.Context);
+
+ Diag << FixItHint::CreateReplacement(
+ ArraySubscriptE->getLHS()->getSourceRange(), RText);
+ Diag << FixItHint::CreateReplacement(
+ ArraySubscriptE->getRHS()->getSourceRange(), LText);
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
Added: clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.h?rev=281206&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.h (added)
+++ clang-tools-extra/trunk/clang-tidy/readability/MisplacedArrayIndexCheck.h Mon Sep 12 07:04:13 2016
@@ -0,0 +1,36 @@
+//===--- MisplacedArrayIndexCheck.h - clang-tidy-----------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MISPLACED_ARRAY_INDEX_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MISPLACED_ARRAY_INDEX_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+/// Warn about unusual array index syntax (`index[array]` instead of
+/// `array[index]`).
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability-misplaced-array-index.html
+class MisplacedArrayIndexCheck : public ClangTidyCheck {
+public:
+ MisplacedArrayIndexCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_MISPLACED_ARRAY_INDEX_H
Modified: clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp?rev=281206&r1=281205&r2=281206&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp Mon Sep 12 07:04:13 2016
@@ -19,6 +19,7 @@
#include "IdentifierNamingCheck.h"
#include "ImplicitBoolCastCheck.h"
#include "InconsistentDeclarationParameterNameCheck.h"
+#include "MisplacedArrayIndexCheck.h"
#include "NamedParameterCheck.h"
#include "NonConstParameterCheck.h"
#include "RedundantControlFlowCheck.h"
@@ -54,6 +55,8 @@ public:
"readability-implicit-bool-cast");
CheckFactories.registerCheck<InconsistentDeclarationParameterNameCheck>(
"readability-inconsistent-declaration-parameter-name");
+ CheckFactories.registerCheck<MisplacedArrayIndexCheck>(
+ "readability-misplaced-array-index");
CheckFactories.registerCheck<StaticDefinitionInAnonymousNamespaceCheck>(
"readability-static-definition-in-anonymous-namespace");
CheckFactories.registerCheck<readability::NamedParameterCheck>(
Modified: clang-tools-extra/trunk/docs/ReleaseNotes.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/ReleaseNotes.rst?rev=281206&r1=281205&r2=281206&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/ReleaseNotes.rst (original)
+++ clang-tools-extra/trunk/docs/ReleaseNotes.rst Mon Sep 12 07:04:13 2016
@@ -89,6 +89,11 @@ Improvements to clang-tidy
Warns about the performance overhead arising from concatenating strings using
the ``operator+``, instead of ``operator+=``.
+- New `readability-misplaced-array-index
+ <http://clang.llvm.org/extra/clang-tidy/checks/readability-misplaced-array-index.html>`_ check
+
+ Warns when there is array index before the [] instead of inside it.
+
- New `readability-non-const-parameter
<http://clang.llvm.org/extra/clang-tidy/checks/readability-non-const-parameter.html>`_ check
Modified: clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst?rev=281206&r1=281205&r2=281206&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst (original)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Mon Sep 12 07:04:13 2016
@@ -128,6 +128,7 @@ Clang-Tidy Checks
readability-identifier-naming
readability-implicit-bool-cast
readability-inconsistent-declaration-parameter-name
+ readability-misplaced-array-index
readability-named-parameter
readability-non-const-parameter
readability-redundant-control-flow
Added: clang-tools-extra/trunk/docs/clang-tidy/checks/readability-misplaced-array-index.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/readability-misplaced-array-index.rst?rev=281206&view=auto
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/readability-misplaced-array-index.rst (added)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/readability-misplaced-array-index.rst Mon Sep 12 07:04:13 2016
@@ -0,0 +1,27 @@
+.. title:: clang-tidy - readability-misplaced-array-index
+
+readability-misplaced-array-index
+=================================
+
+This check warns for unusual array index syntax.
+
+The following code has unusual array index syntax:
+
+.. code-block:: c++
+
+ void f(int *X, int Y) {
+ Y[X] = 0;
+ }
+
+becomes
+
+.. code-block:: c++
+
+ void f(int *X, int Y) {
+ X[Y] = 0;
+ }
+
+The check warns about such unusual syntax for readability reasons:
+ * There are programmers that are not familiar with this unusual syntax.
+ * It is possible that variables are mixed up.
+
Added: clang-tools-extra/trunk/test/clang-tidy/readability-misplaced-array-index.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/readability-misplaced-array-index.cpp?rev=281206&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/readability-misplaced-array-index.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/readability-misplaced-array-index.cpp Mon Sep 12 07:04:13 2016
@@ -0,0 +1,34 @@
+// RUN: %check_clang_tidy %s readability-misplaced-array-index %t
+
+#define ABC "abc"
+
+struct XY { int *X; int *Y; };
+
+void dostuff(int);
+
+void unusualSyntax(int *P1, struct XY *P2) {
+ 10[P1] = 0;
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: confusing array subscript expression, usually the index is inside the []
+ // CHECK-FIXES: P1[10] = 0;
+
+ 10[P2->X] = 0;
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: confusing array subscript expression
+ // CHECK-FIXES: P2->X[10] = 0;
+
+ dostuff(1["abc"]);
+ // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+ // CHECK-FIXES: dostuff("abc"[1]);
+
+ dostuff(1[ABC]);
+ // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+ // CHECK-FIXES: dostuff(ABC[1]);
+
+ dostuff(0[0 + ABC]);
+ // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+ // CHECK-FIXES: dostuff(0[0 + ABC]);
+ // No fixit. Probably the code should be ABC[0]
+}
+
+void normalSyntax(int *X) {
+ X[10] = 0;
+}
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