[clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.
For example:
```
int main() {
long size = 300000;
for( short int i = 0; i < size; ++i) {}
}
```
The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.
The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.
Patch by ztamas.
Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity
Reviewed By: JonasToth, whisperity
Differential Revision: https://reviews.llvm.org/D53974
llvm-svn: 346665
2018-11-13 00:01:39 +08:00
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//===--- TooSmallLoopVariableCheck.h - clang-tidy ---------------*- C++ -*-===//
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//
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2019-01-19 16:50:56 +08:00
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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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[clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.
For example:
```
int main() {
long size = 300000;
for( short int i = 0; i < size; ++i) {}
}
```
The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.
The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.
Patch by ztamas.
Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity
Reviewed By: JonasToth, whisperity
Differential Revision: https://reviews.llvm.org/D53974
llvm-svn: 346665
2018-11-13 00:01:39 +08:00
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_TOOSMALLLOOPVARIABLECHECK_H
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#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_TOOSMALLLOOPVARIABLECHECK_H
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2019-03-25 20:38:26 +08:00
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#include "../ClangTidyCheck.h"
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[clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.
For example:
```
int main() {
long size = 300000;
for( short int i = 0; i < size; ++i) {}
}
```
The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.
The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.
Patch by ztamas.
Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity
Reviewed By: JonasToth, whisperity
Differential Revision: https://reviews.llvm.org/D53974
llvm-svn: 346665
2018-11-13 00:01:39 +08:00
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namespace clang {
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namespace tidy {
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namespace bugprone {
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/// This check gives a warning if a loop variable has a too small type which
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/// might not be able to represent all values which are part of the whole range
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/// in which the loop iterates.
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/// If the loop variable's type is too small we might end up in an infinite
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/// loop. Example:
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/// \code
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/// long size = 294967296l;
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/// for (short i = 0; i < size; ++i) {} { ... }
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/// \endcode
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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-too-small-loop-variable.html
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class TooSmallLoopVariableCheck : public ClangTidyCheck {
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public:
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2019-04-14 20:47:48 +08:00
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TooSmallLoopVariableCheck(StringRef Name, ClangTidyContext *Context);
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void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
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[clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.
For example:
```
int main() {
long size = 300000;
for( short int i = 0; i < size; ++i) {}
}
```
The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.
The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.
Patch by ztamas.
Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity
Reviewed By: JonasToth, whisperity
Differential Revision: https://reviews.llvm.org/D53974
llvm-svn: 346665
2018-11-13 00:01:39 +08:00
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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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2019-04-14 20:47:48 +08:00
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private:
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const unsigned MagnitudeBitsUpperLimit;
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[clang-tidy] new check: bugprone-too-small-loop-variable
The new checker searches for those for loops which has a loop variable with a "too small" type which means this type can't represent all values which are part of the iteration range.
For example:
```
int main() {
long size = 300000;
for( short int i = 0; i < size; ++i) {}
}
```
The short type leads to infinite loop here because it can't store all values in the `[0..size]` interval. In a real use case, size means a container's size which depends on the user input. Which means for small amount of objects the algorithm works, but with a larger user input the software will freeze.
The idea of the checker comes from the LibreOffice project, where the same check was implemented as a clang compiler plugin, called `LoopVarTooSmall` (LLVM licensed).
The idea is the same behind this check, but the code is different because of the different framework.
Patch by ztamas.
Reviewers: alexfh, hokein, aaron.ballman, JonasToth, xazax.hun, whisperity
Reviewed By: JonasToth, whisperity
Differential Revision: https://reviews.llvm.org/D53974
llvm-svn: 346665
2018-11-13 00:01:39 +08:00
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};
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} // namespace bugprone
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} // namespace tidy
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} // namespace clang
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#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_TOOSMALLLOOPVARIABLECHECK_H
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