llvm-project/clang/test/Analysis/ptr-arith.c

283 lines
9.5 KiB
C

// RUN: %clang_cc1 -analyze -analyzer-checker=alpha.core.FixedAddr,alpha.core.PointerArithm,alpha.core.PointerSub,debug.ExprInspection -analyzer-store=region -verify -triple x86_64-apple-darwin9 %s
// RUN: %clang_cc1 -analyze -analyzer-checker=alpha.core.FixedAddr,alpha.core.PointerArithm,alpha.core.PointerSub,debug.ExprInspection -analyzer-store=region -verify -triple i686-apple-darwin9 %s
void clang_analyzer_eval(int);
void f1() {
int a[10];
int *p = a;
++p;
}
char* foo();
void f2() {
char *p = foo();
++p;
}
// This test case checks if we get the right rvalue type of a TypedViewRegion.
// The ElementRegion's type depends on the array region's rvalue type. If it was
// a pointer type, we would get a loc::SymbolVal for '*p'.
void* memchr();
static int
domain_port (const char *domain_b, const char *domain_e,
const char **domain_e_ptr)
{
int port = 0;
const char *p;
const char *colon = memchr (domain_b, ':', domain_e - domain_b);
for (p = colon + 1; p < domain_e ; p++)
port = 10 * port + (*p - '0');
return port;
}
void f3() {
int x, y;
int d = &y - &x; // expected-warning{{Subtraction of two pointers that do not point to the same memory chunk may cause incorrect result}}
int a[10];
int *p = &a[2];
int *q = &a[8];
d = q-p; // no-warning
}
void f4() {
int *p;
p = (int*) 0x10000; // expected-warning{{Using a fixed address is not portable because that address will probably not be valid in all environments or platforms}}
}
void f5() {
int x, y;
int *p;
p = &x + 1; // expected-warning{{Pointer arithmetic done on non-array variables means reliance on memory layout, which is dangerous}}
int a[10];
p = a + 1; // no-warning
}
// Allow arithmetic on different symbolic regions.
void f6(int *p, int *q) {
int d = q - p; // no-warning
}
void null_operand(int *a) {
start:
// LHS is a label, RHS is NULL
clang_analyzer_eval(&&start != 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&&start >= 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&&start > 0); // expected-warning{{TRUE}}
clang_analyzer_eval((&&start - 0) != 0); // expected-warning{{TRUE}}
// LHS is a non-symbolic value, RHS is NULL
clang_analyzer_eval(&a != 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&a >= 0); // expected-warning{{TRUE}}
clang_analyzer_eval(&a > 0); // expected-warning{{TRUE}}
clang_analyzer_eval((&a - 0) != 0); // expected-warning{{TRUE}} expected-warning{{Pointer arithmetic done on non-array variables}}
// LHS is NULL, RHS is non-symbolic
// The same code is used for labels and non-symbolic values.
clang_analyzer_eval(0 != &a); // expected-warning{{TRUE}}
clang_analyzer_eval(0 <= &a); // expected-warning{{TRUE}}
clang_analyzer_eval(0 < &a); // expected-warning{{TRUE}}
// LHS is a symbolic value, RHS is NULL
clang_analyzer_eval(a != 0); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(a >= 0); // expected-warning{{TRUE}}
clang_analyzer_eval(a <= 0); // expected-warning{{UNKNOWN}}
clang_analyzer_eval((a - 0) != 0); // expected-warning{{UNKNOWN}}
// LHS is NULL, RHS is a symbolic value
clang_analyzer_eval(0 != a); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(0 <= a); // expected-warning{{TRUE}}
clang_analyzer_eval(0 < a); // expected-warning{{UNKNOWN}}
}
void const_locs() {
char *a = (char*)0x1000;
char *b = (char*)0x1100;
start:
clang_analyzer_eval(a != b); // expected-warning{{TRUE}}
clang_analyzer_eval(a < b); // expected-warning{{TRUE}}
clang_analyzer_eval(a <= b); // expected-warning{{TRUE}}
clang_analyzer_eval((b-a) == 0x100); // expected-warning{{TRUE}}
clang_analyzer_eval(&&start == a); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(a == &&start); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(&a == (char**)a); // expected-warning{{UNKNOWN}}
clang_analyzer_eval((char**)a == &a); // expected-warning{{UNKNOWN}}
}
void array_matching_types() {
int array[10];
int *a = &array[2];
int *b = &array[5];
clang_analyzer_eval(a != b); // expected-warning{{TRUE}}
clang_analyzer_eval(a < b); // expected-warning{{TRUE}}
clang_analyzer_eval(a <= b); // expected-warning{{TRUE}}
clang_analyzer_eval((b-a) != 0); // expected-warning{{TRUE}}
}
// This takes a different code path than array_matching_types()
void array_different_types() {
int array[10];
int *a = &array[2];
char *b = (char*)&array[5];
clang_analyzer_eval(a != b); // expected-warning{{TRUE}} expected-warning{{comparison of distinct pointer types}}
clang_analyzer_eval(a < b); // expected-warning{{TRUE}} expected-warning{{comparison of distinct pointer types}}
clang_analyzer_eval(a <= b); // expected-warning{{TRUE}} expected-warning{{comparison of distinct pointer types}}
}
struct test { int x; int y; };
void struct_fields() {
struct test a, b;
clang_analyzer_eval(&a.x != &a.y); // expected-warning{{TRUE}}
clang_analyzer_eval(&a.x < &a.y); // expected-warning{{TRUE}}
clang_analyzer_eval(&a.x <= &a.y); // expected-warning{{TRUE}}
clang_analyzer_eval(&a.x != &b.x); // expected-warning{{TRUE}}
clang_analyzer_eval(&a.x > &b.x); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(&a.x >= &b.x); // expected-warning{{UNKNOWN}}
}
void mixed_region_types() {
struct test s;
int array[2];
void *a = &array, *b = &s;
clang_analyzer_eval(&a != &b); // expected-warning{{TRUE}}
clang_analyzer_eval(&a > &b); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(&a >= &b); // expected-warning{{UNKNOWN}}
}
void symbolic_region(int *p) {
int a;
clang_analyzer_eval(&a != p); // expected-warning{{TRUE}}
clang_analyzer_eval(&a > p); // expected-warning{{UNKNOWN}}
clang_analyzer_eval(&a >= p); // expected-warning{{UNKNOWN}}
}
void PR7527 (int *p) {
if (((int) p) & 1) // not crash
return;
}
void use_symbols(int *lhs, int *rhs) {
clang_analyzer_eval(lhs < rhs); // expected-warning{{UNKNOWN}}
if (lhs < rhs)
return;
clang_analyzer_eval(lhs < rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs - rhs); // expected-warning{{UNKNOWN}}
if ((lhs - rhs) != 5)
return;
clang_analyzer_eval((lhs - rhs) == 5); // expected-warning{{TRUE}}
}
void equal_implies_zero(int *lhs, int *rhs) {
clang_analyzer_eval(lhs == rhs); // expected-warning{{UNKNOWN}}
if (lhs == rhs) {
clang_analyzer_eval(lhs != rhs); // expected-warning{{FALSE}}
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{TRUE}}
return;
}
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs != rhs); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{FALSE}}
}
void zero_implies_equal(int *lhs, int *rhs) {
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{UNKNOWN}}
if ((rhs - lhs) == 0) {
clang_analyzer_eval(lhs != rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs == rhs); // expected-warning{{TRUE}}
return;
}
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs != rhs); // expected-warning{{TRUE}}
}
void comparisons_imply_size(int *lhs, int *rhs) {
clang_analyzer_eval(lhs <= rhs); // expected-warning{{UNKNOWN}}
if (lhs > rhs) {
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{FALSE}}
return;
}
clang_analyzer_eval(lhs <= rhs); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) >= 0); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) > 0); // expected-warning{{UNKNOWN}}
if (lhs >= rhs) {
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{TRUE}}
return;
}
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs < rhs); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) > 0); // expected-warning{{TRUE}}
}
void size_implies_comparison(int *lhs, int *rhs) {
clang_analyzer_eval(lhs <= rhs); // expected-warning{{UNKNOWN}}
if ((rhs - lhs) < 0) {
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
return;
}
clang_analyzer_eval(lhs <= rhs); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) >= 0); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) > 0); // expected-warning{{UNKNOWN}}
if ((rhs - lhs) <= 0) {
clang_analyzer_eval(lhs == rhs); // expected-warning{{TRUE}}
return;
}
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
clang_analyzer_eval(lhs < rhs); // expected-warning{{TRUE}}
clang_analyzer_eval((rhs - lhs) > 0); // expected-warning{{TRUE}}
}
//-------------------------------
// False positives
//-------------------------------
void zero_implies_reversed_equal(int *lhs, int *rhs) {
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{UNKNOWN}}
if ((rhs - lhs) == 0) {
// FIXME: Should be FALSE.
clang_analyzer_eval(rhs != lhs); // expected-warning{{UNKNOWN}}
// FIXME: Should be TRUE.
clang_analyzer_eval(rhs == lhs); // expected-warning{{UNKNOWN}}
return;
}
clang_analyzer_eval((rhs - lhs) == 0); // expected-warning{{FALSE}}
// FIXME: Should be FALSE.
clang_analyzer_eval(rhs == lhs); // expected-warning{{UNKNOWN}}
// FIXME: Should be TRUE.
clang_analyzer_eval(rhs != lhs); // expected-warning{{UNKNOWN}}
}
void canonical_equal(int *lhs, int *rhs) {
clang_analyzer_eval(lhs == rhs); // expected-warning{{UNKNOWN}}
if (lhs == rhs) {
// FIXME: Should be TRUE.
clang_analyzer_eval(rhs == lhs); // expected-warning{{UNKNOWN}}
return;
}
clang_analyzer_eval(lhs == rhs); // expected-warning{{FALSE}}
// FIXME: Should be FALSE.
clang_analyzer_eval(rhs == lhs); // expected-warning{{UNKNOWN}}
}