if (rhs.isZeroConstant())
return lhs;
+ // Perserve the null pointer so that it can be found by the DerefChecker.
+ if (lhs.isZeroConstant())
+ return lhs;
+
// We are dealing with pointer arithmetic.
// Handle pointer arithmetic on constant values.
// Offset the increment by the pointer size.
llvm::APSInt Multiplicand(rightI.getBitWidth(), /* isUnsigned */ true);
+ QualType pointeeType = resultTy->getPointeeType();
+ Multiplicand = getContext().getTypeSizeInChars(pointeeType).getQuantity();
rightI *= Multiplicand;
// Compute the adjusted pointer.
--- /dev/null
+// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
+
+int test1() {
+ int *p = (int *)sizeof(int);
+ p -= 1;
+ return *p; // expected-warning {{Dereference of null pointer}}
+}
+
+int test2() {
+ int *p = (int *)sizeof(int);
+ p -= 2;
+ p += 1;
+ return *p; // expected-warning {{Dereference of null pointer}}
+}
+
+int test3() {
+ int *p = (int *)sizeof(int);
+ p++;
+ p--;
+ p--;
+ return *p; // expected-warning {{Dereference of null pointer}}
+}
+
+int test4() {
+ // This is a special case where pointer arithmetic is not calculated to
+ // preserve useful warnings on dereferences of null pointers.
+ int *p = 0;
+ p += 1;
+ return *p; // expected-warning {{Dereference of null pointer}}
+}