llvm-project/clang/test/Analysis/null-deref-offsets.c

38 lines
1.4 KiB
C

// RUN: %clang_analyze_cc1 -w -triple i386-apple-darwin10 -analyzer-checker=core,debug.ExprInspection -verify %s
void clang_analyzer_eval(int);
struct S {
int x, y;
int z[2];
};
void testOffsets(struct S *s, int coin) {
if (s != 0)
return;
// FIXME: Here we are testing the hack that computes offsets to null pointers
// as 0 in order to find null dereferences of not-exactly-null pointers,
// such as &(s->y) below, which is equal to 4 rather than 0 in run-time.
// These are indeed null.
clang_analyzer_eval(s == 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&(s->x) == 0); // expected-warning{{TRUE}}
// FIXME: These should ideally be true.
clang_analyzer_eval(&(s->y) == 4); // expected-warning{{FALSE}}
clang_analyzer_eval(&(s->z[0]) == 8); // expected-warning{{FALSE}}
clang_analyzer_eval(&(s->z[1]) == 12); // expected-warning{{FALSE}}
// FIXME: These should ideally be false.
clang_analyzer_eval(&(s->y) == 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&(s->z[0]) == 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&(s->z[1]) == 0); // expected-warning{{TRUE}}
// But these should still be reported as null dereferences.
if (coin)
s->y = 5; // expected-warning{{Access to field 'y' results in a dereference of a null pointer (loaded from variable 's')}}
else
s->z[1] = 6; // expected-warning{{Array access (via field 'z') results in a null pointer dereference}}
}