[analyzer] Tweak MallocSizeOfChecker to not warn when using sizeof(void*) to allocate a bunch of any pointer type.
This suppresses a common false positive when analyzing libc++.
Along the way, introduce some tests to show this checker actually
works with C++ static_cast<>.
llvm-svn: 220160
diff --git a/clang/test/Analysis/malloc-sizeof.cpp b/clang/test/Analysis/malloc-sizeof.cpp
new file mode 100644
index 0000000..8589975
--- /dev/null
+++ b/clang/test/Analysis/malloc-sizeof.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=unix.MallocSizeof -verify %s
+
+#include <stddef.h>
+
+void *malloc(size_t size);
+void *calloc(size_t nmemb, size_t size);
+void *realloc(void *ptr, size_t size);
+void free(void *ptr);
+
+struct A {};
+struct B {};
+
+void foo(unsigned int unsignedInt, unsigned int readSize) {
+ // Sanity check the checker is working as expected.
+ A* a = static_cast<A*>(malloc(sizeof(int))); // expected-warning {{Result of 'malloc' is converted to a pointer of type 'struct A', which is incompatible with sizeof operand type 'int'}}
+ free(a);
+}
+
+void bar() {
+ A *x = static_cast<A*>(calloc(10, sizeof(void*))); // expected-warning {{Result of 'calloc' is converted to a pointer of type 'struct A', which is incompatible with sizeof operand type 'void *'}}
+ // sizeof(void*) is compatible with any pointer.
+ A **y = static_cast<A**>(calloc(10, sizeof(void*))); // no-warning
+ free(x);
+ free(y);
+}
+