86026ee623
The sizeof operator misuses in loop conditionals can be a source of
bugs. The common misuse is attempting to retrieve the number of elements
in the array by using the sizeof expression and forgetting to divide the
value by the sizeof the array elements. This results in an incorrect
computation of the array length and requires a warning from the sizeof
checker.
Example:
```
int array[20];
void test_for_loop() {
// Needs warning.
for(int i = 0; i < sizeof(array); i++) {
array[i] = i;
}
}
void test_while_loop() {
int count = 0;
// Needs warning.
while(count < sizeof(array)) {
array[count] = 0;
count = count + 2;
}
}
```
rdar://151403083
---------
Co-authored-by: MalavikaSamak <malavika2@apple.com>
41 lines
1.5 KiB
C++
41 lines
1.5 KiB
C++
//===--- SizeofExpressionCheck.h - clang-tidy--------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIZEOFEXPRESSIONCHECK_H
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#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIZEOFEXPRESSIONCHECK_H
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#include "../ClangTidyCheck.h"
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namespace clang::tidy::bugprone {
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/// Find suspicious usages of sizeof expressions.
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///
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/// For the user-facing documentation see:
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/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/sizeof-expression.html
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class SizeofExpressionCheck : public ClangTidyCheck {
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public:
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SizeofExpressionCheck(StringRef Name, ClangTidyContext *Context);
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void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
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void registerMatchers(ast_matchers::MatchFinder *Finder) override;
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void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
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private:
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const bool WarnOnSizeOfConstant;
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const bool WarnOnSizeOfIntegerExpression;
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const bool WarnOnSizeOfThis;
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const bool WarnOnSizeOfCompareToConstant;
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const bool WarnOnSizeOfPointerToAggregate;
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const bool WarnOnSizeOfPointer;
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const bool WarnOnOffsetDividedBySizeOf;
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const bool WarnOnSizeOfInLoopTermination;
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};
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} // namespace clang::tidy::bugprone
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#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIZEOFEXPRESSIONCHECK_H
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