[-Wunsafe-buffer-usage][NFC] Add tests for function pointer call fixits

Author: jkorous-apple

clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-pointer-arg-to-func-ptr-call.cpp

@@ -6,7 +6,43 @@ void unsafe_array_func_ptr_call(void (*fn_ptr)(int *param)) {
   int p[32];
   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::array<int, 32> p"
 
-  int tmp = p[5];
+  p[5] = 10;
   fn_ptr(p);
   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:11}:".data()"
 }
+
+void unsafe_ptr_func_ptr_call(void (*fn_ptr)(int *param)) {
+  int *p;
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:9}:"std::span<int> p"
+
+  p[5] = 10;
+  fn_ptr(p);
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:11}:".data()"
+}
+
+void addr_of_unsafe_ptr_func_ptr_call(void (*fn_ptr)(int *param)) {
+  int *p;
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:9}:"std::span<int> p"
+
+  p[5] = 10;
+  fn_ptr(&p[0]);
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:15}:"p.data()"
+}
+
+void addr_of_unsafe_ptr_w_offset_func_ptr_call(void (*fn_ptr)(int *param)) {
+  int *p;
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:9}:"std::span<int> p"
+
+  p[5] = 10;
+  fn_ptr(&p[3]);
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:15}:"&p.data()[3]"
+}
+
+void preincrement_unsafe_ptr_func_ptr_call(void (*fn_ptr)(int *param)) {
+  int *p;
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:9}:"std::span<int> p"
+
+  p[5] = 10;
+  fn_ptr(++p);
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:13}:"(p = p.subspan(1)).data()"
+}