================
@@ -0,0 +1,74 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=alpha.core.PointerSub -verify %s
+
+void f1(void) {
+  int x, y, z[10];
+  int d = &y - &x; // expected-warning{{Subtraction of two pointers that do 
not point into the same array is undefined behavior}}
+  d = z - &y; // expected-warning{{Subtraction of two pointers that do not 
point into the same array is undefined behavior}}
+  d = &x - &x; // expected-warning{{Subtraction of two pointers that do not 
point into the same array is undefined behavior}}
----------------
steakhal wrote:

The tests look good, except for `&x - &x`, which should be valid.
Wrt. `&x - 1`, that should be valid as well, given that the resulting pointer 
is not dereferenced. However, clang's constrant interpreter disagrees with 
gcc's on that case: https://godbolt.org/z/dMd1rMazY
However, like I said, I believe gcc's right by accepting that code.


https://github.com/llvm/llvm-project/pull/93676
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to