xref: /llvm-project/clang/test/SemaCXX/builtin-assume-aligned.cpp (revision 0dd05d4b5936adcc23a632d9061e9deab57bd088)
1*0dd05d4bSHal Finkel // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -triple x86_64-linux-gnu %s
2*0dd05d4bSHal Finkel 
3*0dd05d4bSHal Finkel int n;
4*0dd05d4bSHal Finkel constexpr int *p = 0;
5*0dd05d4bSHal Finkel // expected-error@+1 {{must be initialized by a constant expression}}
6*0dd05d4bSHal Finkel constexpr int *k = (int *) __builtin_assume_aligned(p, 16, n = 5);
7*0dd05d4bSHal Finkel 
8*0dd05d4bSHal Finkel constexpr void *l = __builtin_assume_aligned(p, 16);
9*0dd05d4bSHal Finkel 
10*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
11*0dd05d4bSHal Finkel // expected-note@+1 {{cast from 'void *' is not allowed in a constant expression}}
12*0dd05d4bSHal Finkel constexpr int *c = (int *) __builtin_assume_aligned(p, 16);
13*0dd05d4bSHal Finkel 
14*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
15*0dd05d4bSHal Finkel // expected-note@+1 {{alignment of the base pointee object (4 bytes) is less than the asserted 16 bytes}}
16*0dd05d4bSHal Finkel constexpr void *m = __builtin_assume_aligned(&n, 16);
17*0dd05d4bSHal Finkel 
18*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
19*0dd05d4bSHal Finkel // expected-note@+1 {{offset of the aligned pointer from the base pointee object (-2 bytes) is not a multiple of the asserted 4 bytes}}
20*0dd05d4bSHal Finkel constexpr void *q1 = __builtin_assume_aligned(&n, 4, 2);
21*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
22*0dd05d4bSHal Finkel // expected-note@+1 {{offset of the aligned pointer from the base pointee object (2 bytes) is not a multiple of the asserted 4 bytes}}
23*0dd05d4bSHal Finkel constexpr void *q2 = __builtin_assume_aligned(&n, 4, -2);
24*0dd05d4bSHal Finkel constexpr void *q3 = __builtin_assume_aligned(&n, 4, 4);
25*0dd05d4bSHal Finkel constexpr void *q4 = __builtin_assume_aligned(&n, 4, -4);
26*0dd05d4bSHal Finkel 
27*0dd05d4bSHal Finkel static char ar1[6];
28*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
29*0dd05d4bSHal Finkel // expected-note@+1 {{alignment of the base pointee object (1 byte) is less than the asserted 16 bytes}}
30*0dd05d4bSHal Finkel constexpr void *r1 = __builtin_assume_aligned(&ar1[2], 16);
31*0dd05d4bSHal Finkel 
32*0dd05d4bSHal Finkel static char ar2[6] __attribute__((aligned(32)));
33*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
34*0dd05d4bSHal Finkel // expected-note@+1 {{offset of the aligned pointer from the base pointee object (2 bytes) is not a multiple of the asserted 16 bytes}}
35*0dd05d4bSHal Finkel constexpr void *r2 = __builtin_assume_aligned(&ar2[2], 16);
36*0dd05d4bSHal Finkel constexpr void *r3 = __builtin_assume_aligned(&ar2[2], 16, 2);
37*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
38*0dd05d4bSHal Finkel // expected-note@+1 {{offset of the aligned pointer from the base pointee object (1 byte) is not a multiple of the asserted 16 bytes}}
39*0dd05d4bSHal Finkel constexpr void *r4 = __builtin_assume_aligned(&ar2[2], 16, 1);
40*0dd05d4bSHal Finkel 
41*0dd05d4bSHal Finkel constexpr int* x = __builtin_constant_p((int*)0xFF) ? (int*)0xFF : (int*)0xFF;
42*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
43*0dd05d4bSHal Finkel // expected-note@+1 {{value of the aligned pointer (255) is not a multiple of the asserted 32 bytes}}
44*0dd05d4bSHal Finkel constexpr void *s1 = __builtin_assume_aligned(x, 32);
45*0dd05d4bSHal Finkel // expected-error@+2 {{must be initialized by a constant expression}}
46*0dd05d4bSHal Finkel // expected-note@+1 {{value of the aligned pointer (250) is not a multiple of the asserted 32 bytes}}
47*0dd05d4bSHal Finkel constexpr void *s2 = __builtin_assume_aligned(x, 32, 5);
48*0dd05d4bSHal Finkel constexpr void *s3 = __builtin_assume_aligned(x, 32, -1);
49*0dd05d4bSHal Finkel 
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