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// RUN: %check_clang_tidy %s performance-inefficient-vector-operation %t -- -format-style=llvm --
namespace std {
typedef int size_t;
template <class T>
class vector {
public:
typedef T* iterator;
typedef const T* const_iterator;
typedef T& reference;
typedef const T& const_reference;
typedef size_t size_type;
explicit vector();
explicit vector(size_type n);
void push_back(const T& val);
void reserve(size_t n);
void resize(size_t n);
size_t size();
const_reference operator[] (size_type) const;
reference operator[] (size_type);
};
} // namespace std
void f(std::vector<int>& t) {
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(10);
for (int i = 0; i < 10; ++i)
v.push_back(i);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called inside a loop; consider pre-allocating the vector capacity before the loop
}
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(10);
for (int i = 0; i < 10; i++)
v.push_back(i);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(10);
for (int i = 0; i < 10; ++i)
v.push_back(0);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(5);
for (int i = 0; i < 5; ++i) {
v.push_back(i);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
// CHECK-FIXES-NOT: v.reserve(10);
for (int i = 0; i < 10; ++i) {
// No fix for this loop as we encounter the prior loops.
v.push_back(i);
}
}
{
std::vector<int> v;
std::vector<int> v2;
v2.reserve(3);
// CHECK-FIXES: v.reserve(10);
for (int i = 0; i < 10; ++i)
v.push_back(i);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(t.size());
for (std::size_t i = 0; i < t.size(); ++i) {
v.push_back(t[i]);
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
}
{
std::vector<int> v;
// CHECK-FIXES: v.reserve(t.size() - 1);
for (std::size_t i = 0; i < t.size() - 1; ++i) {
v.push_back(t[i]);
} // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: 'push_back' is called
}
// ---- Non-fixed Cases ----
{
std::vector<int> v;
v.reserve(20);
// CHECK-FIXES-NOT: v.reserve(10);
// There is a "reserve" call already.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
v.reserve(5);
// CHECK-FIXES-NOT: v.reserve(10);
// There is a "reserve" call already.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
v.resize(5);
// CHECK-FIXES-NOT: v.reserve(10);
// There is a ref usage of v before the loop.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
v.push_back(0);
// CHECK-FIXES-NOT: v.reserve(10);
// There is a ref usage of v before the loop.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
f(v);
// CHECK-FIXES-NOT: v.reserve(10);
// There is a ref usage of v before the loop.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v(20);
// CHECK-FIXES-NOT: v.reserve(10);
// v is not constructed with default constructor.
for (int i = 0; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
// CHECK-FIXES-NOT: v.reserve(10);
// For-loop is not started with 0.
for (int i = 1; i < 10; ++i) {
v.push_back(i);
}
}
{
std::vector<int> v;
// CHECK-FIXES-NOT: v.reserve(t.size());
// v isn't referenced in for-loop body.
for (std::size_t i = 0; i < t.size(); ++i) {
t.push_back(i);
}
}
{
std::vector<int> v;
int k;
// CHECK-FIXES-NOT: v.reserve(10);
// For-loop isn't a fixable loop.
for (std::size_t i = 0; k < 10; ++i) {
v.push_back(t[i]);
}
}
{
std::vector<int> v;
// CHECK-FIXES-NOT: v.reserve(i + 1);
// The loop end expression refers to the loop variable i.
for (int i = 0; i < i + 1; i++)
v.push_back(i);
}
{
std::vector<int> v;
int k;
// CHECK-FIXES-NOT: v.reserve(10);
// For-loop isn't a fixable loop.
for (std::size_t i = 0; i < 10; ++k) {
v.push_back(t[i]);
}
}
}
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