[clang-tidy] Add a clang-tidy check for possible inefficient vector operations

Summary:
The "performance-inefficient-vector-operation" check finds vector oprations in
for-loop statements which may cause multiple memory reallocations.

This is the first version, only detects typical for-loop:

```
std::vector<int> v;
for (int i = 0; i < n; ++i) {
  v.push_back(i);
}

// or

for (int i = 0; i < v2.size(); ++i) {
  v.push_back(v2[i]);
}
```

We can extend it to handle more cases like for-range loop in the future.

Reviewers: alexfh, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: zaks.anna, Eugene.Zelenko, mgorny, cfe-commits, djasper

Differential Revision: https://reviews.llvm.org/D31757

llvm-svn: 300534

1 files changed, 3 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/performance/PerformanceTidyModule.cpp b/clang-tools-extra/clang-tidy/performance/PerformanceTidyModule.cpp
index 90255c5e2b6..072f817eedb 100644
--- a/clang-tools-extra/clang-tidy/performance/PerformanceTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/performance/PerformanceTidyModule.cpp
@@ -14,6 +14,7 @@
 #include "ForRangeCopyCheck.h"
 #include "ImplicitCastInLoopCheck.h"
 #include "InefficientStringConcatenationCheck.h"
+#include "InefficientVectorOperationCheck.h"
 #include "TypePromotionInMathFnCheck.h"
 #include "UnnecessaryCopyInitialization.h"
 #include "UnnecessaryValueParamCheck.h"
@@ -33,6 +34,8 @@ public:
         "performance-implicit-cast-in-loop");
     CheckFactories.registerCheck<InefficientStringConcatenationCheck>(
         "performance-inefficient-string-concatenation");
+    CheckFactories.registerCheck<InefficientVectorOperationCheck>(
+        "performance-inefficient-vector-operation");
     CheckFactories.registerCheck<TypePromotionInMathFnCheck>(
         "performance-type-promotion-in-math-fn");
     CheckFactories.registerCheck<UnnecessaryCopyInitialization>(