[Diagnostics] Add -Wsizeof-array-div

Summary: Clang version of https://www.viva64.com/en/examples/v706/

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D67287

llvm-svn: 371605

1 files changed, 28 insertions, 0 deletions

diff --git a/clang/test/Sema/div-sizeof-array.cpp b/clang/test/Sema/div-sizeof-array.cpp
new file mode 100644
index 00000000000..1c34666d05d
--- /dev/null
+++ b/clang/test/Sema/div-sizeof-array.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 %s -verify -Wsizeof-array-div -fsyntax-only
+
+template <typename Ty, int N>
+int f(Ty (&Array)[N]) {
+  return sizeof(Array) / sizeof(Ty); // Should not warn
+}
+
+typedef int int32;
+
+void test(void) {
+  int arr[12];                // expected-note 2 {{array 'arr' declared here}}
+  unsigned long long arr2[4];
+  int *p = &arr[0];
+  int a1 = sizeof(arr) / sizeof(*arr);
+  int a2 = sizeof arr / sizeof p; // expected-warning {{expression does not compute the number of elements in this array; element type is 'int', not 'int *'}}
+  int a4 = sizeof arr2 / sizeof p;
+  int a5 = sizeof(arr) / sizeof(short); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int', not 'short'}}
+  int a6 = sizeof(arr) / sizeof(int32);
+  int a7 = sizeof(arr) / sizeof(int);
+  int a9 = sizeof(arr) / sizeof(unsigned int);
+  const char arr3[2] = "A";
+  int a10 = sizeof(arr3) / sizeof(char);
+
+  int arr4[10][12];                         // expected-note 3 {{array 'arr4' declared here}}
+  int b1 = sizeof(arr4) / sizeof(arr2[12]); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'unsigned long long'}}
+  int b2 = sizeof(arr4) / sizeof(int *);    // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'int *'}}
+  int b3 = sizeof(arr4) / sizeof(short *);  // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'short *'}}
+}