/* $NetBSD: d_c99_init.c,v 1.45 2023/03/28 14:44:34 rillig Exp $ */
# 3 "d_c99_init.c"
/*
* Test C99 initializers.
*
* See C99 6.7.8 "Initialization".
*/
/* lint1-extra-flags: -X 351 */
void use(const void *);
typedef struct any {
const void *value;
} any;
// C99 6.7.8p11 says "optionally enclosed in braces". Whether this wording
// means "a single pair of braces" or "as many pairs of braces as you want"
// is left for interpretation to the reader.
int scalar_without_braces = 3;
int scalar_with_optional_braces = { 3 };
int scalar_with_too_many_braces = {{ 3 }};
/* expect+1: error: too many initializers [174] */
int scalar_with_too_many_initializers = { 3, 5 };
// See initialization_expr, 'handing over to INIT'.
void
struct_initialization_via_assignment(any arg)
{
any local = arg;
use(&local);
}
// See initialization_expr, initialization_init_array_from_string.
char static_duration[] = "static duration";
signed char static_duration_signed[] = "static duration";
unsigned char static_duration_unsigned[] = "static duration";
int static_duration_wchar[] = L"static duration";
// See init_expr.
void
initialization_by_braced_string(void)
{
any local = { "hello" };
use(&local);
}
void
initialization_by_redundantly_braced_string(void)
{
any local = {{{{ "hello" }}}};
use(&local);
}
/*
* Only scalar expressions and string literals may be enclosed by additional
* braces. Since 'arg' is a struct, this is a compile-time error.
*/
void
initialization_with_too_many_braces(any arg)
{
/* expect+1: error: cannot initialize 'pointer to const void' from 'struct any' [185] */
any local = { arg };
use(&arg);
}
// Some of the following examples are mentioned in the introduction comment
// in init.c.
int number = 12345;
int number_with_braces_and_comma = {
12345,
};
int array_with_fixed_size[3] = {
111,
222,
333,
/* expect+1: error: too many array initializers, expected 3 [173] */
444,
};
// See update_type_of_array_of_unknown_size.
int array_of_unknown_size[] = {
111,
222,
333,
};
int array_flat[2][2] = {
11,
12,
21,
22
};
int array_nested[2][2] = {
{
11,
12
},
{
21,
22
}
};
int array_with_designators[] = {
['1'] = 111,
['5'] = 555,
['9'] = 999
};
int array_with_some_designators[] = {
['1'] = 111,
222,
['9'] = 999
};
struct point {
int x;
int y;
};
struct point point = {
3,
4
};
struct point point_with_designators = {
.y = 4,
.x = 3,
};
struct point point_with_mixed_designators = {
.x = 3,
4,
/* expect+1: error: too many struct/union initializers [172] */
5,
.x = 3,
};
/*
* Before cgram.y 1.230 from 2021-06-20, the grammar allowed either of the
* operators '.' or '->' to be used for the designators and had extra code
* to ensure that only '.' was actually used.
*/
struct point origin = {
.x = 0,
/* expect+1: error: syntax error '->' [249] */
->y = 0,
};
/* Ensure that the parser can recover from the parse error. */
struct point pythagoras = { 3, 4 };
int array_with_designator[] = {
111,
/* expect+1: error: syntax error 'designator '.member' is only for struct/union' [249] */
.member = 222,
333,
};
/*
* C99 6.7.8p11 says that the initializer of a scalar can be "optionally
* enclosed in braces". It does not explicitly set an upper limit on the
* number of braces. It also doesn't restrict the term "initializer" to only
* mean the "outermost initializer". 6.7.8p13 defines that a brace for a
* structure or union always means to descend into the type. Both GCC 10 and
* Clang 8 already warn about these extra braces, nevertheless there is
* real-life code (the Postfix MTA) that exploits this corner case of the
* standard.
*/
struct point scalar_with_several_braces = {
{{{3}}},
{{{{4}}}},
};
struct rectangle {
struct point top_left;
struct point bottom_right;
};
/* C99 6.7.8p18 */
struct rectangle screen = {
.bottom_right = {
1920,
1080,
}
};
/*
* C99 6.7.8p22 says: At the _end_ of its initializer list, the array no
* longer has incomplete type.
*/
struct point points[] = {
{
/*
* At this point, the size of the object 'points' is not known
* yet since its type is still incomplete. Lint could warn
* about this, but GCC and Clang already do.
*
* Before init.c 1.179 from 2021.03.30, the type information
* of 'points' was set too early, resulting in a negative
* array size below.
*/
sizeof(int[-(int)sizeof(points)]),
4
}
};
struct triangle {
struct point points[3];
};
struct pentagon {
struct point points[5];
};
struct geometry {
struct pentagon pentagons[6];
struct triangle triangles[10];
struct point points[3][5][2];
};
/*
* Initialization of a complex struct containing nested arrays and nested
* structs.
*/
struct geometry geometry = {
.pentagons[0].points[4].x = 1,
.points[0][0][0] = { 0, 0 },
.points[2][4][1] = {301, 302 },
/* expect+1: error: array subscript cannot be > 2: 3 [168] */
.points[3][0][0] = {3001, 3002 },
/* expect+1: error: array subscript cannot be > 4: 5 [168] */
.points[0][5][0] = {501, 502 },
/* expect+1: error: array subscript cannot be > 1: 2 [168] */
.points[0][0][2] = {21, 22 },
};
struct ends_with_unnamed_bit_field {
int member;
int:0;
} ends_with_unnamed_bit_field = {
12345,
/* expect+1: error: too many struct/union initializers [172] */
23456,
};
char prefixed_message[] = {
'E', ':', ' ',
/* expect+1: warning: illegal combination of integer 'char' and pointer 'pointer to char' [183] */
"message\n",
};
char message_with_suffix[] = {
"message",
/* The excess character is not detected by lint but by compilers. */
'\n',
};
struct ten {
int i0;
int i1;
int i2;
int i3;
int i4;
int i5;
int i6;
int i7;
int i8;
int i9;
};
struct ten ten = {
.i3 = 3,
4,
5,
6,
};
/*
* ISO C99 6.7.8 provides a large list of examples for initialization,
* covering all tricky edge cases.
*/
int c99_6_7_8_p24_example1_i = 3.5;
double _Complex c99_6_7_8_p24_example1_c = 5 + 3 * 1.0fi;
int c99_6_7_8_p25_example2[] = { 1, 3, 5 };
int c99_6_7_8_p26_example3a[4][3] = {
{ 1, 3, 5 },
{ 2, 4, 6 },
{ 3, 5, 7 },
};
int c99_6_7_8_p26_example3b[4][3] = {
1, 3, 5, 2, 4, 6, 3, 5, 7
};
int c99_6_7_8_p27_example4[4][3] = {
{ 1 }, { 2 }, { 3 }, { 4 }
};
struct {
int a[3], b;
} c99_6_7_8_p28_example5[] = {
{ 1 },
2,
};
short c99_6_7_8_p29_example6a[4][3][2] = {
{ 1 },
{ 2, 3 },
{ 4, 5, 6 },
};
short c99_6_7_8_p29_example6b[4][3][2] = {
1, 0, 0, 0, 0, 0,
2, 3, 0, 0, 0, 0,
4, 5, 6, 0, 0, 0,
};
short c99_6_7_8_p29_example6c[4][3][2] = {
{
{ 1 },
},
{
{ 2, 3 },
},
{
{ 4, 5 },
{ 6 },
}
};
void
c99_6_7_8_p31_example7(void)
{
typedef int A[];
A a = { 1, 2 }, b = { 3, 4, 5 };
/* expect+1: error: negative array dimension (-8) [20] */
typedef int reveal_sizeof_a[-(int)(sizeof(a))];
/* expect+1: error: negative array dimension (-12) [20] */
typedef int reveal_sizeof_b[-(int)(sizeof(b))];
}
char c99_6_7_8_p32_example8_s1[] = "abc",
c99_6_7_8_p32_example8_t1[3] = "abc";
char c99_6_7_8_p32_example8_s2[] = { 'a', 'b', 'c', '\0' },
c99_6_7_8_p32_example8_t2[3] = { 'a', 'b', 'c' };
char *c99_6_7_8_p32_example8_p = "abc";
enum { member_one, member_two };
const char *c99_6_7_8_p33_example9[] = {
[member_two] = "member two",
[member_one] = "member one",
};
struct {
int quot, rem;
} c99_6_7_8_p34_example10 = { .quot = 2, .rem = -1 };
struct { int a[3], b; } c99_6_7_8_p35_example11[] =
{ [0].a = {1}, [1].a[0] = 2 };
int c99_6_7_8_p36_example12a[16] = {
1, 3, 5, 7, 9, [16-5] = 8, 6, 4, 2, 0
};
int c99_6_7_8_p36_example12b[8] = {
1, 3, 5, 7, 9, [8-5] = 8, 6, 4, 2, 0
};
union {
int first_member;
void *second_member;
unsigned char any_member;
} c99_6_7_8_p38_example13 = { .any_member = 42 };
/*
* During initialization of an object of type array of unknown size, the type
* information on the symbol is updated in-place. Ensure that this happens on
* a copy of the type.
*
* C99 6.7.8p31 example 7
*/
void
ensure_array_type_is_not_modified_during_initialization(void)
{
typedef int array_of_unknown_size[];
array_of_unknown_size a1 = { 1, 2, 3};
switch (4) {
case sizeof(array_of_unknown_size):
/* expect+1: error: duplicate case in switch: 0 [199] */
case 0:
case 3:
case 4:
case 12:
break;
}
/* expect+1: error: negative array dimension (-12) [20] */
typedef int reveal_sizeof_a1[-(int)(sizeof(a1))];
}
struct point unknown_member_name_beginning = {
/* expect+1: error: type 'struct point' does not have member 'r' [101] */
.r = 5,
.x = 4,
.y = 3,
};
struct point unknown_member_name_middle = {
.x = 4,
/* expect+1: error: type 'struct point' does not have member 'r' [101] */
.r = 5,
.y = 3,
};
struct point unknown_member_name_end = {
.x = 4,
.y = 3,
/* expect+1: error: type 'struct point' does not have member 'r' [101] */
.r = 5,
};
union value {
int int_value;
void *pointer_value;
};
union value unknown_union_member_name_first = {
/* expect+1: error: type 'union value' does not have member 'unknown_value' [101] */
.unknown_value = 4,
.int_value = 3,
};
union value unknown_union_member_name_second = {
.int_value = 3,
/* expect+1: error: type 'union value' does not have member 'unknown_value' [101] */
.unknown_value = 4,
};
struct point subscript_designator_on_struct = {
/* expect+1: error: syntax error 'designator '[...]' is only for arrays' [249] */
[0] = 3,
};
struct point unknown_member_on_struct = {
/* expect+1: error: type 'struct point' does not have member 'member' [101] */
.member[0][0].member = 4,
};
struct point unknown_member_on_scalar = {
/* expect+1: error: syntax error 'scalar type cannot use designator' [249] */
.x.y.z = 5,
};
struct {
int:16;
/* expect+2: warning: 'struct <unnamed>' has no named members [65] */
/* expect+1: error: cannot initialize struct/union with no named member [179] */
} struct_with_only_unnamed_members = {
123,
};
union {
int:16;
/* expect+2: warning: 'union <unnamed>' has no named members [65] */
/* expect+1: error: cannot initialize struct/union with no named member [179] */
} union_with_only_unnamed_members = {
123,
};
int designator_for_scalar = {
/* expect+1: error: syntax error 'scalar type cannot use designator' [249] */
.value = 3,
};
struct point member_designator_for_scalar_in_struct = {
/* expect+1: error: syntax error 'scalar type cannot use designator' [249] */
{ .x = 3 },
};
struct point subscript_designator_for_scalar_in_struct = {
/* expect+1: error: syntax error 'designator '[...]' is only for arrays' [249] */
{ [1] = 4 },
};
/* Seen in pcidevs_data.h, variable 'pci_words'. */
const char string_initialized_with_braced_literal[] = {
"initializer",
};
// An array of unknown size containing strings.
char weekday_names[][4] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
/* nested struct/union initialization */
struct outer {
int i;
char c;
union inner {
short us;
char uc;
} u;
char *s;
} struct_containing_union[] = {
{
.s = "foo",
.c = 'b',
.u = {
.uc = 'c'
}
},
{
.i = 1,
.c = 'a',
.u = {
.us = 2
}
},
};
/*
* The expansion of the offsetof macro may dereference a null pointer.
* Such expressions are allowed in initializers for objects with
* static duration.
*/
struct offset_and_data {
unsigned long offset;
unsigned long data;
};
struct offset_and_data offset_and_data = {
(unsigned long)&(((struct offset_and_data *)0)->data),
0,
};
// The size of the array is determined by the maximum index, not by the last
// one mentioned.
int arr_11[] = { [10] = 10, [0] = 0 };
typedef int ctassert_11[-(int)(sizeof(arr_11) / sizeof(arr_11[0]))];
/* expect-1: error: negative array dimension (-11) [20] */
// Without an explicit subscript designator, the subscript counts up.
int arr_3[] = { [1] = 1, [0] = 0, 1, 2 };
typedef int ctassert_3[-(int)(sizeof(arr_3) / sizeof(arr_3[0]))];
/* expect-1: error: negative array dimension (-3) [20] */