================
@@ -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}}
----------------
NagyDonat wrote:
> Wrt. `&x - 1`, that should be valid as well, given that the resulting pointer
> is not dereferenced.
The standard explicitly disallows this, see [[expr.add] part
4.2](http://eel.is/c++draft/expr.add#4.2) and 4.3 (in the most recent C++ draft
standard, other versions may be different).
https://github.com/llvm/llvm-project/pull/93676
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