llvm-project/clang/test/Analysis/string-fail.c

114 lines
3.5 KiB
C

// RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.experimental.CString,deadcode.experimental.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,unix.experimental.CString,deadcode.experimental.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
// XFAIL: *
// This file is for tests that may eventually go into string.c, or may be
// deleted outright. At one point these tests passed, but only because we
// weren't correctly modelling the behavior of the relevant string functions.
// The tests aren't incorrect, but require the analyzer to be smarter about
// conjured values than it currently is.
//===----------------------------------------------------------------------===
// Declarations
//===----------------------------------------------------------------------===
// Some functions are so similar to each other that they follow the same code
// path, such as memcpy and __memcpy_chk, or memcmp and bcmp. If VARIANT is
// defined, make sure to use the variants instead to make sure they are still
// checked by the analyzer.
// Some functions are implemented as builtins. These should be #defined as
// BUILTIN(f), which will prepend "__builtin_" if USE_BUILTINS is defined.
// Functions that have variants and are also available as builtins should be
// declared carefully! See memcpy() for an example.
#ifdef USE_BUILTINS
# define BUILTIN(f) __builtin_ ## f
#else /* USE_BUILTINS */
# define BUILTIN(f) f
#endif /* USE_BUILTINS */
#define NULL 0
typedef typeof(sizeof(int)) size_t;
//===----------------------------------------------------------------------===
// strnlen()
//===----------------------------------------------------------------------===
#define strnlen BUILTIN(strnlen)
size_t strnlen(const char *s, size_t maxlen);
void strnlen_liveness(const char *x) {
if (strnlen(x, 10) < 5)
return;
if (strnlen(x, 10) < 5)
(void)*(char*)0; // no-warning
}
void strnlen_subregion() {
struct two_stringsn { char a[2], b[2]; };
extern void use_two_stringsn(struct two_stringsn *);
struct two_stringsn z;
use_two_stringsn(&z);
size_t a = strnlen(z.a, 10);
z.b[0] = 5;
size_t b = strnlen(z.a, 10);
if (a == 0 && b != 0)
(void)*(char*)0; // expected-warning{{never executed}}
use_two_stringsn(&z);
size_t c = strnlen(z.a, 10);
if (a == 0 && c != 0)
(void)*(char*)0; // expected-warning{{null}}
}
extern void use_stringn(char *);
void strnlen_argument(char *x) {
size_t a = strnlen(x, 10);
size_t b = strnlen(x, 10);
if (a == 0 && b != 0)
(void)*(char*)0; // expected-warning{{never executed}}
use_stringn(x);
size_t c = strnlen(x, 10);
if (a == 0 && c != 0)
(void)*(char*)0; // expected-warning{{null}}
}
extern char global_strn[];
void strnlen_global() {
size_t a = strnlen(global_strn, 10);
size_t b = strnlen(global_strn, 10);
if (a == 0 && b != 0)
(void)*(char*)0; // expected-warning{{never executed}}
// Call a function with unknown effects, which should invalidate globals.
use_stringn(0);
size_t c = strnlen(global_strn, 10);
if (a == 0 && c != 0)
(void)*(char*)0; // expected-warning{{null}}
}
void strnlen_indirect(char *x) {
size_t a = strnlen(x, 10);
char *p = x;
char **p2 = &p;
size_t b = strnlen(x, 10);
if (a == 0 && b != 0)
(void)*(char*)0; // expected-warning{{never executed}}
extern void use_stringn_ptr(char*const*);
use_stringn_ptr(p2);
size_t c = strnlen(x, 10);
if (a == 0 && c != 0)
(void)*(char*)0; // expected-warning{{null}}
}