[clang-tidy] new check cppcoreguidelines-pro-bounds-pointer-arithmetic
Summary:
This check flags all usage of pointer arithmetic, because it could lead
to an
invalid pointer.
Subtraction of two pointers is not flagged by this check.
Pointers should only refer to single objects, and pointer arithmetic is
fragile and easy to get wrong. array_view is a bounds-checked, safe type
for accessing arrays of data.
This rule is part of the "Bounds safety" profile of the C++ Core
Guidelines, see
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-bounds1-dont-use-pointer-arithmetic-use-array_view-instead
Depends on D13313
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13311
llvm-svn: 250116
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt b/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
index d35b9a5..6147914 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
@@ -2,6 +2,7 @@
add_clang_library(clangTidyCppCoreGuidelinesModule
CppCoreGuidelinesTidyModule.cpp
+ ProBoundsPointerArithmeticCheck.cpp
ProTypeConstCastCheck.cpp
ProTypeReinterpretCastCheck.cpp
ProTypeStaticCastDowncastCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
index 358bd6e..07ba15a 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
@@ -10,6 +10,7 @@
#include "../ClangTidy.h"
#include "../ClangTidyModule.h"
#include "../ClangTidyModuleRegistry.h"
+#include "ProBoundsPointerArithmeticCheck.h"
#include "ProTypeConstCastCheck.h"
#include "ProTypeReinterpretCastCheck.h"
#include "ProTypeStaticCastDowncastCheck.h"
@@ -22,6 +23,8 @@
class CppCoreGuidelinesModule : public ClangTidyModule {
public:
void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+ CheckFactories.registerCheck<ProBoundsPointerArithmeticCheck>(
+ "cppcoreguidelines-pro-bounds-pointer-arithmetic");
CheckFactories.registerCheck<ProTypeConstCastCheck>(
"cppcoreguidelines-pro-type-const-cast");
CheckFactories.registerCheck<ProTypeReinterpretCastCheck>(
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
new file mode 100644
index 0000000..15ea27a
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
@@ -0,0 +1,53 @@
+//===--- ProBoundsPointerArithmeticCheck.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 "ProBoundsPointerArithmeticCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+
+void ProBoundsPointerArithmeticCheck::registerMatchers(MatchFinder *Finder) {
+ if (!getLangOpts().CPlusPlus)
+ return;
+
+ // Flag all operators +, -, +=, -=, ++, -- that result in a pointer
+ Finder->addMatcher(
+ binaryOperator(anyOf(hasOperatorName("+"), hasOperatorName("-"),
+ hasOperatorName("+="), hasOperatorName("-=")),
+ hasType(pointerType()))
+ .bind("expr"),
+ this);
+
+ Finder->addMatcher(
+ unaryOperator(anyOf(hasOperatorName("++"), hasOperatorName("--")),
+ hasType(pointerType()))
+ .bind("expr"),
+ this);
+
+ // Array subscript on a pointer (not an array) is also pointer arithmetic
+ Finder->addMatcher(
+ arraySubscriptExpr(hasBase(ignoringImpCasts(anyOf(hasType(pointerType()),
+ hasType(decayedType(hasDecayedType(pointerType())))))))
+ .bind("expr"),
+ this);
+}
+
+void
+ProBoundsPointerArithmeticCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *MatchedExpr = Result.Nodes.getNodeAs<Expr>("expr");
+
+ diag(MatchedExpr->getExprLoc(), "do not use pointer arithmetic");
+}
+
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.h b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.h
new file mode 100644
index 0000000..f3a3fb1
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.h
@@ -0,0 +1,34 @@
+//===--- ProBoundsPointerArithmeticCheck.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_CPPCOREGUIDELINES_PRO_BOUNDS_POINTER_ARITHMETIC_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_BOUNDS_POINTER_ARITHMETIC_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+
+/// Flags all kinds of pointer arithmetic that have result of pointer type, i.e.
+/// +, -, +=, -=, ++, --. In addition, the [] operator on pointers (not on arrays) is flagged.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/cppcoreguidelines-pro-bounds-pointer-arithmetic.html
+class ProBoundsPointerArithmeticCheck : public ClangTidyCheck {
+public:
+ ProBoundsPointerArithmeticCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CPPCOREGUIDELINES_PRO_BOUNDS_POINTER_ARITHMETIC_H