[clang-tidy] Add check 'readability-redundant-member-init'

Summary: The check emits a warning if a member-initializer calls the member's default constructor with no arguments.

Reviewers: sbenza, alexfh, aaron.ballman

Subscribers: modocache, mgorny, Eugene.Zelenko, etienneb, Prazek, hokein, cfe-commits, beanz

Differential Revision: https://reviews.llvm.org/D24339

llvm-svn: 284742

1 files changed, 181 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/readability-redundant-member-init.cpp b/clang-tools-extra/test/clang-tidy/readability-redundant-member-init.cpp
new file mode 100644
index 00000000000..70a21552706
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/readability-redundant-member-init.cpp
@@ -0,0 +1,181 @@
+// RUN: %check_clang_tidy %s readability-redundant-member-init %t
+
+struct S {
+  S() = default;
+  S(int i) : i(i) {}
+  int i = 1;
+};
+
+struct T {
+  T(int i = 1) : i(i) {}
+  int i;
+};
+
+struct U {
+  int i;
+};
+
+union V {
+  int i;
+  double f;
+};
+
+// Initializer calls default constructor
+struct F1 {
+  F1() : f() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for member 'f' is redundant
+  // CHECK-FIXES: F1()  {}
+  S f;
+};
+
+// Initializer calls default constructor with default argument
+struct F2 {
+  F2() : f() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for member 'f' is redundant
+  // CHECK-FIXES: F2()  {}
+  T f;
+};
+
+// Multiple redundant initializers for same constructor
+struct F3 {
+  F3() : f(), g(1), h() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for member 'f' is redundant
+  // CHECK-MESSAGES: :[[@LINE-2]]:21: warning: initializer for member 'h' is redundant
+  // CHECK-FIXES: F3() :  g(1) {}
+  S f, g, h;
+};
+
+// Templated class independent type
+template <class V>
+struct F4 {
+  F4() : f() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for member 'f' is redundant
+  // CHECK-FIXES: F4()  {}
+  S f;
+};
+F4<int> f4i;
+F4<S> f4s;
+
+// Base class
+struct F5 : S {
+  F5() : S() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for base class 'S' is redundant
+  // CHECK-FIXES: F5()  {}
+};
+
+// Constructor call requires cleanup
+struct Cleanup {
+  ~Cleanup() {}
+};
+
+struct UsesCleanup {
+  UsesCleanup(const Cleanup &c = Cleanup()) {}
+};
+
+struct F6 {
+  F6() : uc() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for member 'uc' is redundant
+  // CHECK-FIXES: F6()  {}
+  UsesCleanup uc;
+};
+
+// Multiple inheritance
+struct F7 : S, T {
+  F7() : S(), T() {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: initializer for base class 'S' is redundant
+  // CHECK-MESSAGES: :[[@LINE-2]]:15: warning: initializer for base class 'T' is redundant
+  // CHECK-FIXES: F7()  {}
+};
+
+// Initializer not written
+struct NF1 {
+  NF1() {}
+  S f;
+};
+
+// Initializer doesn't call default constructor
+struct NF2 {
+  NF2() : f(1) {}
+  S f;
+};
+
+// Initializer calls default constructor without using default argument
+struct NF3 {
+  NF3() : f(1) {}
+  T f;
+};
+
+// Initializer calls default constructor without using default argument
+struct NF4 {
+  NF4() : f(2) {}
+  T f;
+};
+
+// Initializer is zero-initialization
+struct NF5 {
+  NF5() : i() {}
+  int i;
+};
+
+// Initializer is direct-initialization
+struct NF6 {
+  NF6() : i(1) {}
+  int i;
+};
+
+// Initializer is aggregate initialization of struct
+struct NF7 {
+  NF7() : f{} {}
+  U f;
+};
+
+// Initializer is zero-initialization of struct
+struct NF7b {
+  NF7b() : f() {}
+  U f;
+};
+
+// Initializer is aggregate initialization of array
+struct NF8 {
+  NF8() : f{} {}
+  int f[2];
+};
+
+struct NF9 {
+  NF9() : f{} {}
+  S f[2];
+};
+
+// Initializing member of union
+union NF10 {
+  NF10() : s() {}
+  int i;
+  S s;
+};
+
+// Templated class dependent type
+template <class V>
+struct NF11 {
+  NF11() : f() {}
+  V f;
+};
+NF11<int> nf11i;
+NF11<S> nf11s;
+
+// Delegating constructor
+class NF12 {
+  NF12() = default;
+  NF12(int) : NF12() {}
+};
+
+// Const member
+struct NF13 {
+  NF13() : f() {}
+  const S f;
+};
+
+// Union member
+struct NF14 {
+  NF14() : f() {}
+  V f;
+};