llvm-project/clang/test/Sema/address-packed.c
Vladimir Vuksanovic 9d1dd9a264
[Sema] Fix false positive warnings for misaligned member access (#150025)
These warnings are reported on a per expression basis, however some
potential misaligned accesses are discarded before that happens. The
problem is when a new expression starts while processing another
expression. The new expression will end first and emit all potential
misaligned accesses collected up to that point. That includes candidates
that were found in the parent expression, even though they might have
gotten discarded later.

Fixed by checking if the candidate is located withing the currently
processed expression.

Fixes #144729
2025-08-14 06:14:43 -07:00

349 lines
7.6 KiB
C

// RUN: %clang_cc1 -fsyntax-only -verify %s
#include <stdint.h>
extern void f1(int *);
extern void f2(char *);
struct Ok {
char c;
int x;
};
struct __attribute__((packed)) Arguable {
char c0;
int x;
char c1;
};
union __attribute__((packed)) UnionArguable {
char c;
int x;
};
typedef struct Arguable ArguableT;
struct Arguable *get_arguable(void);
void to_void(void *);
void to_intptr(intptr_t);
void g0(void) {
{
struct Ok ok;
f1(&ok.x); // no-warning
f2(&ok.c); // no-warning
}
{
struct Arguable arguable;
f2(&arguable.c0); // no-warning
f1(&arguable.x); // expected-warning {{packed member 'x' of class or structure 'Arguable'}}
f2(&arguable.c1); // no-warning
f1((int *)(void *)&arguable.x); // no-warning
to_void(&arguable.x); // no-warning
void *p = &arguable.x; // no-warning
to_void(p);
to_intptr((intptr_t)p); // no-warning
}
{
union UnionArguable arguable;
f2(&arguable.c); // no-warning
f1(&arguable.x); // expected-warning {{packed member 'x' of class or structure 'UnionArguable'}}
f1((int *)(void *)&arguable.x); // no-warning
to_void(&arguable.x); // no-warning
to_intptr((intptr_t)&arguable.x); // no-warning
}
{
ArguableT arguable;
f2(&arguable.c0); // no-warning
f1(&arguable.x); // expected-warning {{packed member 'x' of class or structure 'Arguable'}}
f2(&arguable.c1); // no-warning
f1((int *)(void *)&arguable.x); // no-warning
to_void(&arguable.x); // no-warning
to_intptr((intptr_t)&arguable.x); // no-warning
}
{
struct Arguable *arguable = get_arguable();
f2(&arguable->c0); // no-warning
f1(&arguable->x); // expected-warning {{packed member 'x' of class or structure 'Arguable'}}
f2(&arguable->c1); // no-warning
f1((int *)(void *)&arguable->x); // no-warning
to_void(&arguable->c1); // no-warning
to_intptr((intptr_t)&arguable->c1); // no-warning
}
{
ArguableT *arguable = get_arguable();
f2(&(arguable->c0)); // no-warning
f1(&(arguable->x)); // expected-warning {{packed member 'x' of class or structure 'Arguable'}}
f2(&(arguable->c1)); // no-warning
f1((int *)(void *)&(arguable->x)); // no-warning
to_void(&(arguable->c1)); // no-warning
to_intptr((intptr_t)&(arguable->c1)); // no-warning
}
}
struct S1 {
char c;
int i __attribute__((packed));
};
int *g1(struct S1 *s1) {
return &s1->i; // expected-warning {{packed member 'i' of class or structure 'S1'}}
}
struct S2_i {
int i;
};
struct __attribute__((packed)) S2 {
char c;
struct S2_i inner;
};
int *g2(struct S2 *s2) {
return &s2->inner.i; // expected-warning {{packed member 'inner' of class or structure 'S2'}}
}
struct S2_a {
char c;
struct S2_i inner __attribute__((packed));
};
int *g2_a(struct S2_a *s2_a) {
return &s2_a->inner.i; // expected-warning {{packed member 'inner' of class or structure 'S2_a'}}
}
struct __attribute__((packed)) S3 {
char c;
struct {
int i;
} inner;
};
int *g3(struct S3 *s3) {
return &s3->inner.i; // expected-warning {{packed member 'inner' of class or structure 'S3'}}
}
struct S4 {
char c;
struct __attribute__((packed)) {
int i;
} inner;
};
int *g4(struct S4 *s4) {
return &s4->inner.i; // expected-warning {{packed member 'i' of class or structure 'S4::struct (unnamed at}}
}
struct S5 {
char c;
struct {
char c1;
int i __attribute__((packed));
} inner;
};
int *g5(struct S5 *s5) {
return &s5->inner.i; // expected-warning {{packed member 'i' of class or structure 'S5::struct (unnamed at}}
}
struct __attribute__((packed, aligned(2))) AlignedTo2 {
int x;
};
char *g6(struct AlignedTo2 *s) {
return (char *)&s->x; // no-warning
}
struct __attribute__((packed, aligned(2))) AlignedTo2Bis {
int x;
};
struct AlignedTo2Bis* g7(struct AlignedTo2 *s)
{
return (struct AlignedTo2Bis*)&s->x; // no-warning
}
typedef struct {
char c;
int x;
} __attribute__((packed)) TypedefStructArguable;
typedef union {
char c;
int x;
} __attribute((packed)) TypedefUnionArguable;
typedef TypedefStructArguable TypedefStructArguableTheSecond;
int *typedef1(TypedefStructArguable *s) {
return &s->x; // expected-warning {{packed member 'x' of class or structure 'TypedefStructArguable'}}
}
int *typedef2(TypedefStructArguableTheSecond *s) {
return &s->x; // expected-warning {{packed member 'x' of class or structure 'TypedefStructArguable'}}
}
int *typedef3(TypedefUnionArguable *s) {
return &s->x; // expected-warning {{packed member 'x' of class or structure 'TypedefUnionArguable'}}
}
struct S6 {
union {
char c;
int x;
} __attribute__((packed));
};
int *anonymousInnerUnion(struct S6 *s) {
return &s->x; // expected-warning {{packed member 'x' of class or structure 'S6::union (anonymous at}}
}
struct S6a {
int a;
int _;
int c;
char __;
int d;
} __attribute__((packed, aligned(16))) s6;
void g8(void)
{
f1(&s6.a); // no-warning
f1(&s6.c); // no-warning
f1(&s6.d); // expected-warning {{packed member 'd' of class or structure 'S6a'}}
}
struct __attribute__((packed, aligned(1))) MisalignedContainee { double d; };
struct __attribute__((aligned(8))) AlignedContainer { struct MisalignedContainee b; };
struct AlignedContainer *p;
double* g9(void) {
return &p->b.d; // no-warning
}
union OneUnion
{
uint32_t a;
uint32_t b:1;
};
struct __attribute__((packed)) S7 {
uint8_t length;
uint8_t stuff;
uint8_t padding[2];
union OneUnion one_union;
};
union AnotherUnion {
long data;
struct S7 s;
} *au;
union OneUnion* get_OneUnion(void)
{
return &au->s.one_union; // no-warning
}
struct __attribute__((packed)) S8 {
uint8_t data1;
uint8_t data2;
uint16_t wider_data;
};
#define LE_READ_2(p) \
((uint16_t) \
((((const uint8_t *)(p))[0] ) | \
(((const uint8_t *)(p))[1] << 8)))
uint32_t get_wider_data(struct S8 *s)
{
return LE_READ_2(&s->wider_data); // no-warning
}
struct S9 {
uint32_t x;
uint8_t y[2];
uint16_t z;
} __attribute__((__packed__));
typedef struct S9 __attribute__((__aligned__(16))) aligned_S9;
void g10(void) {
struct S9 x;
struct S9 __attribute__((__aligned__(8))) y;
aligned_S9 z;
uint32_t *p32;
p32 = &x.x; // expected-warning {{packed member 'x' of class or structure 'S9'}}
p32 = &y.x; // no-warning
p32 = &z.x; // no-warning
}
typedef struct {
uint32_t msgh_bits;
uint32_t msgh_size;
int32_t msgh_voucher_port;
int32_t msgh_id;
} S10Header;
typedef struct {
uint32_t t;
uint64_t m;
uint32_t p;
union {
struct {
uint32_t a;
double z;
} __attribute__((aligned(8), packed)) a;
struct {
uint32_t b;
double z;
uint32_t a;
} __attribute__((aligned(8), packed)) b;
};
} __attribute__((aligned(8), packed)) S10Data;
typedef struct {
S10Header hdr;
uint32_t size;
uint8_t count;
S10Data data[] __attribute__((aligned(8)));
} __attribute__((aligned(8), packed)) S10;
void g11(S10Header *hdr);
void g12(S10 *s) {
g11(&s->hdr); // no-warning
}
struct S11 {
uint32_t x;
} __attribute__((__packed__));
void g13(void) {
struct S11 __attribute__((__aligned__(4))) a[4];
uint32_t *p32;
p32 = &a[0].x; // no-warning
}
struct Invalid0 {
void *x;
struct fwd f; // expected-error {{incomplete type}} expected-note {{forward declaration}}
} __attribute__((packed));
void *g14(struct Invalid0 *ivl) {
return &(ivl->x);
}
void to_void_with_expr(void *ptr, int expr);
void g15(void) {
struct Arguable arguable;
to_void_with_expr(&arguable.x, 3); // no-warning
to_void_with_expr(&arguable.x, ({3;})); // no-warning
}