[clang-tidy] Add non-constant references in function parameters check.

Summary: This is implemented originally by Alexander Kornienko.

Reviewers: alexfh

Subscribers: cfe-commits


Patch by Haojian Wu!

Differential Revision: http://reviews.llvm.org/D16717

llvm-svn: 259530

1 files changed, 139 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/google-runtime-references.cpp b/clang-tools-extra/test/clang-tidy/google-runtime-references.cpp
new file mode 100644
index 00000000000..fc82a8feb18
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/google-runtime-references.cpp
@@ -0,0 +1,139 @@
+// RUN: %check_clang_tidy %s google-runtime-references %t -- -- -std=c++11
+
+int a;
+int &b = a;
+int *c;
+void f1(int a);
+void f2(int *b);
+void f3(const int &c);
+void f4(int const &d);
+
+// Don't warn on implicit operator= in c++11 mode.
+class A {
+  virtual void f() {}
+};
+// Don't warn on rvalue-references.
+struct A2 {
+  A2(A2&&) = default;
+  void f(A2&&) {}
+};
+
+// Don't warn on iostream parameters.
+namespace xxx {
+class istream { };
+class ostringstream { };
+}
+void g1(xxx::istream &istr);
+void g1(xxx::ostringstream &istr);
+
+void g1(int &a);
+// CHECK-MESSAGES: [[@LINE-1]]:14: warning: non-const reference parameter 'a', make it const or use a pointer [google-runtime-references]
+
+struct s {};
+void g2(int a, int b, s c, s &d);
+// CHECK-MESSAGES: [[@LINE-1]]:31: warning: non-const reference parameter 'd', {{.*}}
+
+typedef int &ref;
+void g3(ref a);
+// CHECK-MESSAGES: [[@LINE-1]]:13: warning: non-const reference {{.*}}
+
+void g4(int &a, int &b, int &);
+// CHECK-MESSAGES: [[@LINE-1]]:14: warning: non-const reference parameter 'a', {{.*}}
+// CHECK-MESSAGES: [[@LINE-2]]:22: warning: non-const reference parameter 'b', {{.*}}
+// CHECK-MESSAGES: [[@LINE-3]]:30: warning: non-const reference parameter '', {{.*}}
+
+class B {
+  B(B& a) {}
+// CHECK-MESSAGES: [[@LINE-1]]:8: warning: non-const reference {{.*}}
+  virtual void f(int &a) {}
+// CHECK-MESSAGES: [[@LINE-1]]:23: warning: non-const reference {{.*}}
+  void g(int &b);
+// CHECK-MESSAGES: [[@LINE-1]]:15: warning: non-const reference {{.*}}
+
+  // Don't warn on the parameter of stream extractors defined as members.
+  B& operator>>(int& val) { return *this; }
+};
+
+// Only warn on the first declaration of each function to reduce duplicate
+// warnings.
+void B::g(int &b) {}
+
+// Don't warn on the first parameter of stream inserters.
+A& operator<<(A& s, int&) { return s; }
+// CHECK-MESSAGES: [[@LINE-1]]:25: warning: non-const reference parameter '', {{.*}}
+
+// Don't warn on either parameter of stream extractors. Both need to be
+// non-const references by convention.
+A& operator>>(A& input, int& val) { return input; }
+
+// Don't warn on lambdas.
+auto lambda = [] (int&) {};
+
+// Don't warn on typedefs, as we'll warn on the function itself.
+typedef int (*fp)(int &);
+
+// Don't warn on function references.
+typedef void F();
+void g5(const F& func) {}
+void g6(F& func) {}
+
+template<typename T>
+void g7(const T& t) {}
+
+template<typename T>
+void g8(T t) {}
+
+void f5() {
+  g5(f5);
+  g6(f5);
+  g7(f5);
+  g7<F&>(f5);
+  g8(f5);
+  g8<F&>(f5);
+}
+
+// Don't warn on dependent types.
+template<typename T>
+void g9(T& t) {}
+template<typename T>
+void g10(T t) {}
+
+void f6() {
+  int i;
+  float f;
+  g9<int>(i);
+  g9<const int>(i);
+  g9<int&>(i);
+  g10<int&>(i);
+  g10<float&>(f);
+}
+
+// Warn only on the overridden methods from the base class, as the child class
+// only implements the interface.
+class C : public B {
+  C();
+  virtual void f(int &a) {}
+};
+
+// Don't warn on operator<< with streams-like interface.
+A& operator<<(A& s, int) { return s; }
+
+// Don't warn on swap().
+void swap(C& c1, C& c2) {}
+
+// Don't warn on standalone operator++, operator--, operator+=, operator-=,
+// operator*=, etc. that all need non-const references to be functional.
+A& operator++(A& a) { return a; }
+A operator++(A& a, int) { return a; }
+A& operator--(A& a) { return a; }
+A operator--(A& a, int) { return a; }
+A& operator+=(A& a, const A& b) { return a; }
+A& operator-=(A& a, const A& b) { return a; }
+A& operator*=(A& a, const A& b) { return a; }
+A& operator/=(A& a, const A& b) { return a; }
+A& operator%=(A& a, const A& b) { return a; }
+A& operator<<=(A& a, const A& b) { return a; }
+A& operator>>=(A& a, const A& b) { return a; }
+A& operator|=(A& a, const A& b) { return a; }
+A& operator^=(A& a, const A& b) { return a; }
+A& operator&=(A& a, const A& b) { return a; }