llvm-project/clang/test/Analysis/malloc.c

264 lines
6.5 KiB
C

// RUN: %clang_cc1 -analyze -analyzer-checker=core,deadcode.experimental.UnreachableCode,core.experimental.CastSize,unix.experimental.Malloc -analyzer-store=region -verify %s
typedef __typeof(sizeof(int)) size_t;
void *malloc(size_t);
void free(void *);
void *realloc(void *ptr, size_t size);
void *calloc(size_t nmemb, size_t size);
void __attribute((ownership_returns(malloc))) *my_malloc(size_t);
void __attribute((ownership_takes(malloc, 1))) my_free(void *);
void __attribute((ownership_returns(malloc, 1))) *my_malloc2(size_t);
void __attribute((ownership_holds(malloc, 1))) my_hold(void *);
// Duplicate attributes are silly, but not an error.
// Duplicate attribute has no extra effect.
// If two are of different kinds, that is an error and reported as such.
void __attribute((ownership_holds(malloc, 1)))
__attribute((ownership_holds(malloc, 1)))
__attribute((ownership_holds(malloc, 3))) my_hold2(void *, void *, void *);
void *my_malloc3(size_t);
void *myglobalpointer;
struct stuff {
void *somefield;
};
struct stuff myglobalstuff;
void f1() {
int *p = malloc(12);
return; // expected-warning{{Allocated memory never released. Potential memory leak.}}
}
void f2() {
int *p = malloc(12);
free(p);
free(p); // expected-warning{{Try to free a memory block that has been released}}
}
void f2_realloc_0() {
int *p = malloc(12);
realloc(p,0);
realloc(p,0); // expected-warning{{Try to free a memory block that has been released}}
}
void f2_realloc_1() {
int *p = malloc(12);
int *q = realloc(p,0); // expected-warning{{Assigned value is garbage or undefined}}
}
// ownership attributes tests
void naf1() {
int *p = my_malloc3(12);
return; // no-warning
}
void n2af1() {
int *p = my_malloc2(12);
return; // expected-warning{{Allocated memory never released. Potential memory leak.}}
}
void af1() {
int *p = my_malloc(12);
return; // expected-warning{{Allocated memory never released. Potential memory leak.}}
}
void af1_b() {
int *p = my_malloc(12); // expected-warning{{Allocated memory never released. Potential memory leak.}}
}
void af1_c() {
myglobalpointer = my_malloc(12); // no-warning
}
void af1_d() {
struct stuff mystuff;
mystuff.somefield = my_malloc(12); // expected-warning{{Allocated memory never released. Potential memory leak.}}
}
// Test that we can pass out allocated memory via pointer-to-pointer.
void af1_e(void **pp) {
*pp = my_malloc(42); // no-warning
}
void af1_f(struct stuff *somestuff) {
somestuff->somefield = my_malloc(12); // no-warning
}
// Allocating memory for a field via multiple indirections to our arguments is OK.
void af1_g(struct stuff **pps) {
*pps = my_malloc(sizeof(struct stuff)); // no-warning
(*pps)->somefield = my_malloc(42); // no-warning
}
void af2() {
int *p = my_malloc(12);
my_free(p);
free(p); // expected-warning{{Try to free a memory block that has been released}}
}
void af2b() {
int *p = my_malloc(12);
free(p);
my_free(p); // expected-warning{{Try to free a memory block that has been released}}
}
void af2c() {
int *p = my_malloc(12);
free(p);
my_hold(p); // expected-warning{{Try to free a memory block that has been released}}
}
void af2d() {
int *p = my_malloc(12);
free(p);
my_hold2(0, 0, p); // expected-warning{{Try to free a memory block that has been released}}
}
// No leak if malloc returns null.
void af2e() {
int *p = my_malloc(12);
if (!p)
return; // no-warning
free(p); // no-warning
}
// This case would inflict a double-free elsewhere.
// However, this case is considered an analyzer bug since it causes false-positives.
void af3() {
int *p = my_malloc(12);
my_hold(p);
free(p); // no-warning
}
// This case would inflict a double-free elsewhere.
// However, this case is considered an analyzer bug since it causes false-positives.
int * af4() {
int *p = my_malloc(12);
my_free(p);
return p; // no-warning
}
// This case is (possibly) ok, be conservative
int * af5() {
int *p = my_malloc(12);
my_hold(p);
return p; // no-warning
}
// This case tests that storing malloc'ed memory to a static variable which is
// then returned is not leaked. In the absence of known contracts for functions
// or inter-procedural analysis, this is a conservative answer.
int *f3() {
static int *p = 0;
p = malloc(12);
return p; // no-warning
}
// This case tests that storing malloc'ed memory to a static global variable
// which is then returned is not leaked. In the absence of known contracts for
// functions or inter-procedural analysis, this is a conservative answer.
static int *p_f4 = 0;
int *f4() {
p_f4 = malloc(12);
return p_f4; // no-warning
}
int *f5() {
int *q = malloc(12);
q = realloc(q, 20);
return q; // no-warning
}
void f6() {
int *p = malloc(12);
if (!p)
return; // no-warning
else
free(p);
}
void f6_realloc() {
int *p = malloc(12);
if (!p)
return; // no-warning
else
realloc(p,0);
}
char *doit2();
void pr6069() {
char *buf = doit2();
free(buf);
}
void pr6293() {
free(0);
}
void f7() {
char *x = (char*) malloc(4);
free(x);
x[0] = 'a'; // expected-warning{{Use dynamically allocated memory after it is freed.}}
}
void f7_realloc() {
char *x = (char*) malloc(4);
realloc(x,0);
x[0] = 'a'; // expected-warning{{Use dynamically allocated memory after it is freed.}}
}
void PR6123() {
int *x = malloc(11); // expected-warning{{Cast a region whose size is not a multiple of the destination type size.}}
}
void PR7217() {
int *buf = malloc(2); // expected-warning{{Cast a region whose size is not a multiple of the destination type size.}}
buf[1] = 'c'; // not crash
}
void mallocCastToVoid() {
void *p = malloc(2);
const void *cp = p; // not crash
free(p);
}
void mallocCastToFP() {
void *p = malloc(2);
void (*fp)() = p; // not crash
free(p);
}
// This tests that malloc() buffers are undefined by default
char mallocGarbage () {
char *buf = malloc(2);
char result = buf[1]; // expected-warning{{undefined}}
free(buf);
return result;
}
// This tests that calloc() buffers need to be freed
void callocNoFree () {
char *buf = calloc(2,2);
return; // expected-warning{{never released}}
}
// These test that calloc() buffers are zeroed by default
char callocZeroesGood () {
char *buf = calloc(2,2);
char result = buf[3]; // no-warning
if (buf[1] == 0) {
free(buf);
}
return result; // no-warning
}
char callocZeroesBad () {
char *buf = calloc(2,2);
char result = buf[3]; // no-warning
if (buf[1] != 0) {
free(buf); // expected-warning{{never executed}}
}
return result; // expected-warning{{never released}}
}