[clang-tidy] Add a checker that removes deducible arguments from std::make_pair

Those may be incompatible with C++11 and are unnecessary. We suggest
removing the template arguments when they match the types of the make_pair
arguments or replace it with std::pair and explicit template arguments when
not.

Differential Revision: http://reviews.llvm.org/D4497

llvm-svn: 213058

1 files changed, 44 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/google-explicit-make-pair.cpp b/clang-tools-extra/test/clang-tidy/google-explicit-make-pair.cpp
new file mode 100644
index 00000000000..257fd0621c7
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/google-explicit-make-pair.cpp
@@ -0,0 +1,44 @@
+// RUN: $(dirname %s)/check_clang_tidy_fix.sh %s google-build-explicit-make-pair %t
+// REQUIRES: shell
+
+namespace std {
+template <class T1, class T2>
+struct pair {
+  pair(T1 x, T2 y) {}
+};
+
+template <class T1, class T2>
+pair<T1, T2> make_pair(T1 x, T2 y) {
+  return pair<T1, T2>(x, y);
+}
+}
+
+template <typename T>
+void templ(T a, T b) {
+  std::make_pair<T, unsigned>(a, b);
+}
+
+void test(int i) {
+  std::make_pair<int, int>(i, i);
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: for C++11-compatibility, omit template arguments from make_pair
+// CHECK-FIXES: std::make_pair(i, i)
+
+  std::make_pair<unsigned, int>(i, i);
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: for C++11-compatibility, use pair directly
+// CHECK-FIXES: std::pair<unsigned, int>(i, i)
+
+  std::make_pair<int, unsigned>(i, i);
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: for C++11-compatibility, use pair directly
+// CHECK-FIXES: std::pair<int, unsigned>(i, i)
+
+#define M std::make_pair<int, unsigned>(i, i);
+M
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: for C++11-compatibility, use pair directly
+// Can't fix in macros.
+// CHECK-FIXES: #define M std::make_pair<int, unsigned>(i, i);
+// CHECK-FIXES-NEXT: M
+
+  templ(i, i);
+
+  std::make_pair(i, 1); // no-warning
+}