Add the misc-misplaced-const check to clang-tidy, which diagnoses when a const-qualifier is applied to a typedef of pointer type rather than to the pointee type.

llvm-svn: 272025

2 files changed, 82 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/misc-misplaced-const.c b/clang-tools-extra/test/clang-tidy/misc-misplaced-const.c
new file mode 100644
index 00000000000..cccf3a4506f
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/misc-misplaced-const.c
@@ -0,0 +1,45 @@
+// RUN: %check_clang_tidy %s misc-misplaced-const %t
+
+typedef int plain_i;
+typedef int *ip;
+typedef const int *cip;
+
+typedef void (*func_ptr)(void);
+
+void func(void) {
+  // ok
+  const int *i0 = 0;
+  const plain_i *i1 = 0;
+  const cip i2 = 0; // const applies to both pointer and pointee.
+
+  // Not ok
+  const ip i3 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: 'i3' declared with a const-qualified typedef type; results in the type being 'int *const' instead of 'const int *'
+
+  ip const i4 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: 'i4' declared with a const-qualified
+
+  const volatile ip i5 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: 'i5' declared with a const-qualified typedef type; results in the type being 'int *const volatile' instead of 'const int *volatile'
+}
+
+void func2(const plain_i *i1,
+           const cip i2,
+           const ip i3,
+           // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: 'i3' declared with a const-qualified
+           const int *i4) {
+}
+
+struct S {
+  const int *i0;
+  const plain_i *i1;
+  const cip i2;
+  const ip i3;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: 'i3' declared with a const-qualified
+};
+
+// Function pointers should not be diagnosed because a function
+// pointer type can never be const.
+void func3(const func_ptr fp) {
+  const func_ptr fp2 = fp;
+}
diff --git a/clang-tools-extra/test/clang-tidy/misc-misplaced-const.cpp b/clang-tools-extra/test/clang-tidy/misc-misplaced-const.cpp
new file mode 100644
index 00000000000..5483cabae7f
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/misc-misplaced-const.cpp
@@ -0,0 +1,37 @@
+// RUN: %check_clang_tidy %s misc-misplaced-const %t
+
+typedef int plain_i;
+typedef int *ip;
+typedef const int *cip;
+
+void func() {
+  if (const int *i = 0)
+    ;
+  if (const plain_i *i = 0)
+    ;
+  if (const cip i = 0)
+    ;
+
+  // CHECK-MESSAGES: :[[@LINE+1]]:16: warning: 'i' declared with a const-qualified typedef type; results in the type being 'int *const' instead of 'const int *'
+  if (const ip i = 0)
+    ;
+}
+
+template <typename Ty>
+struct S {
+  const Ty *i;
+  const Ty &i2;
+};
+
+template struct S<int>;
+template struct S<ip>; // ok
+template struct S<cip>;
+template struct S<int *>; // ok
+
+struct T {
+  typedef void (T::*PMF)();
+
+  void f() {
+    const PMF val = &T::f; // ok
+  }
+};