d0p1/tcc-stupidos
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Fix sizeof(char[a])

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The sizes of VLAs need to be evaluated even inside sizeof,
i.e. when nocode_wanted is set.
This commit is contained in:
Michael Matz 2016-09-03 23:55:54 +02:00
parent 49bb5a7e06
commit 9656560f14
2 changed files with 25 additions and 12 deletions
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27
tccgen.c
View file

@ -3792,7 +3792,7 @@ static int asm_label_instr(void)
return v;
}
static void post_type(CType *type, AttributeDef *ad)
static void post_type(CType *type, AttributeDef *ad, int storage)
{
int n, l, t1, arg_size, align;
Sym **plast, *s, *first;
@ -3870,6 +3870,7 @@ static void post_type(CType *type, AttributeDef *ad)
type->t = VT_FUNC;
type->ref = s;
} else if (tok == '[') {
int saved_nocode_wanted = nocode_wanted;
/* array definition */
next();
if (tok == TOK_RESTRICT1)
@ -3877,9 +3878,16 @@ static void post_type(CType *type, AttributeDef *ad)
n = -1;
t1 = 0;
if (tok != ']') {
if (!local_stack || nocode_wanted)
vpushi(expr_const());
else gexpr();
if (!local_stack || (storage & VT_STATIC))
vpushi(expr_const());
else {
/* VLAs (which can only happen with local_stack && !VT_STATIC)
length must always be evaluated, even under nocode_wanted,
so that its size slot is initialized (e.g. under sizeof
or typeof). */
nocode_wanted = 0;
gexpr();
}
if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
n = vtop->c.i;
if (n < 0)
@ -3892,7 +3900,7 @@ static void post_type(CType *type, AttributeDef *ad)
}
skip(']');
/* parse next post type */
post_type(type, ad);
post_type(type, ad, storage);
if (type->t == VT_FUNC)
tcc_error("declaration of an array of functions");
t1 |= type->t & VT_VLA;
@ -3910,6 +3918,7 @@ static void post_type(CType *type, AttributeDef *ad)
}
if (n != -1)
vpop();
nocode_wanted = saved_nocode_wanted;
/* we push an anonymous symbol which will contain the array
element type */
@ -3984,13 +3993,7 @@ static void type_decl(CType *type, AttributeDef *ad, int *v, int td)
}
storage = type->t & VT_STORAGE;
type->t &= ~VT_STORAGE;
if (storage & VT_STATIC) {
int saved_nocode_wanted = nocode_wanted;
nocode_wanted = 1;
post_type(type, ad);
nocode_wanted = saved_nocode_wanted;
} else
post_type(type, ad);
post_type(type, ad, storage);
type->t |= storage;
if (tok == TOK_ATTRIBUTE1 || tok == TOK_ATTRIBUTE2)
parse_attribute(ad);

10
tests/tcctest.c
View file

@ -2456,6 +2456,16 @@ void sizeof_test(void)
printf("__alignof__(char) = %d\n", __alignof__(char));
printf("__alignof__(unsigned char) = %d\n", __alignof__(unsigned char));
printf("__alignof__(func) = %d\n", __alignof__ sizeof_test());
/* sizes of VLAs need to be evaluated even inside sizeof: */
a = 2;
printf("sizeof(char[1+2*a]) = %d\n", sizeof(char[1+2*a]));
/* And checking if sizeof compound literal works. Parenthesized: */
printf("sizeof( (struct {int i; int j;}){4,5} ) = %d\n",
sizeof( (struct {int i; int j;}){4,5} ));
/* And as direct sizeof argument (as unary expression): */
printf("sizeof (struct {short i; short j;}){4,5} = %d\n",
sizeof (struct {short i; short j;}){4,5} );
}
void typeof_test(void)