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decl.c
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decl.c
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#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
#include "cc.h"
static struct decl *tentativedefns, **tentativedefnsend = &tentativedefns;
struct qualtype {
struct type *type;
enum typequal qual;
struct expr *expr;
};
enum storageclass {
SCNONE,
SCTYPEDEF = 1<<1,
SCEXTERN = 1<<2,
SCSTATIC = 1<<3,
SCAUTO = 1<<4,
SCREGISTER = 1<<5,
SCTHREADLOCAL = 1<<6,
};
enum typespec {
SPECNONE,
SPECVOID = 1<<1,
SPECCHAR = 1<<2,
SPECBOOL = 1<<3,
SPECINT = 1<<4,
SPECFLOAT = 1<<5,
SPECDOUBLE = 1<<6,
SPECSHORT = 1<<7,
SPECLONG = 1<<8,
SPECLONG2 = 1<<9,
SPECSIGNED = 1<<10,
SPECUNSIGNED = 1<<11,
SPECCOMPLEX = 1<<12,
SPECLONGLONG = SPECLONG|SPECLONG2,
};
enum funcspec {
FUNCNONE,
FUNCINLINE = 1<<1,
FUNCNORETURN = 1<<2,
};
struct structbuilder {
struct type *type;
struct member **last;
unsigned bits; /* number of bits remaining in the last byte */
bool pack;
};
struct decl *
mkdecl(char *name, enum declkind k, struct type *t, enum typequal tq, enum linkage linkage)
{
struct decl *d;
d = xmalloc(sizeof(*d));
memset(d, 0, sizeof(*d));
d->name = name;
d->kind = k;
d->linkage = linkage;
d->type = t;
d->qual = tq;
if (k == DECLOBJECT && t)
d->u.obj.align = t->align;
return d;
}
/* 6.7.1 Storage-class specifiers */
static int
storageclass(enum storageclass *sc)
{
enum storageclass allowed, new;
switch (tok.kind) {
case TTYPEDEF: new = SCTYPEDEF; break;
case TEXTERN: new = SCEXTERN; break;
case TSTATIC: new = SCSTATIC; break;
case TTHREAD_LOCAL: new = SCTHREADLOCAL; break;
case TAUTO: new = SCAUTO; break;
case TREGISTER: new = SCREGISTER; break;
default: return 0;
}
if (!sc)
error(&tok.loc, "storage class not allowed in this declaration");
switch (*sc) {
case SCNONE: allowed = ~SCNONE; break;
case SCTHREADLOCAL: allowed = SCSTATIC|SCEXTERN; break;
case SCSTATIC:
case SCEXTERN: allowed = SCTHREADLOCAL; break;
default: allowed = SCNONE; break;
}
if (new & ~allowed)
error(&tok.loc, "invalid combination of storage class specifiers");
*sc |= new;
next();
return 1;
}
/* 6.7.3 Type qualifiers */
static int
typequal(enum typequal *tq)
{
switch (tok.kind) {
case TCONST: *tq |= QUALCONST; break;
case TVOLATILE: *tq |= QUALVOLATILE; break;
case TRESTRICT: *tq |= QUALRESTRICT; break;
case T_ATOMIC: error(&tok.loc, "_Atomic type qualifier is not yet supported");
default: return 0;
}
next();
return 1;
}
/* 6.7.4 Function specifiers */
static int
funcspec(enum funcspec *fs)
{
enum funcspec new;
switch (tok.kind) {
case TINLINE: new = FUNCINLINE; break;
case T_NORETURN: new = FUNCNORETURN; break;
default: return 0;
}
if (!fs)
error(&tok.loc, "function specifier not allowed in this declaration");
*fs |= new;
next();
return 1;
}
static void structdecl(struct scope *, struct structbuilder *);
static struct qualtype declspecs(struct scope *, enum storageclass *, enum funcspec *, int *);
static struct type *
tagspec(struct scope *s)
{
static struct type *const inttypes[][2] = {
{&typeuint, &typeint},
{&typeulong, &typelong},
{&typeullong, &typellong},
};
struct type *t, *et;
char *tag, *name;
enum typekind kind;
struct decl *d, *enumconsts;
struct expr *e;
struct attr a;
enum attrkind allowedattr;
struct structbuilder b;
unsigned long long value, max, min;
bool sign;
int i;
allowedattr = 0;
switch (tok.kind) {
case TSTRUCT: kind = TYPESTRUCT, allowedattr |= ATTRPACKED; break;
case TUNION: kind = TYPEUNION; break;
case TENUM: kind = TYPEENUM; break;
default: fatal("internal error: unknown tag kind");
}
next();
a.kind = 0;
attr(&a, allowedattr);
gnuattr(&a, allowedattr);
tag = NULL;
t = NULL;
et = NULL;
if (tok.kind == TIDENT) {
tag = tok.lit;
next();
}
if (kind == TYPEENUM && consume(TCOLON)) {
et = declspecs(s, NULL, NULL, NULL).type;
if (!et)
error(&tok.loc, "no type in enum type specifier");
}
if (tag)
t = scopegettag(s, tag, tok.kind != TLBRACE && tok.kind != TSEMICOLON);
if (t) {
if (t->kind != kind)
error(&tok.loc, "redeclaration of tag '%s' with different kind", tag);
} else {
if (kind == TYPEENUM) {
t = mktype(kind, PROPSCALAR|PROPARITH|PROPREAL|PROPINT);
t->base = et;
} else {
t = mktype(kind, 0);
t->size = 0;
t->align = 0;
t->u.structunion.tag = tag;
t->u.structunion.members = NULL;
}
t->incomplete = true;
if (tag)
scopeputtag(s, tag, t);
}
if (tok.kind != TLBRACE)
return t;
if (!t->incomplete)
error(&tok.loc, "redefinition of tag '%s'", tag);
next();
switch (t->kind) {
case TYPESTRUCT:
case TYPEUNION:
b.type = t;
b.last = &t->u.structunion.members;
b.bits = 0;
b.pack = a.kind & ATTRPACKED;
do structdecl(s, &b);
while (tok.kind != TRBRACE);
if (!t->u.structunion.members)
error(&tok.loc, "struct/union has no members");
next();
if (!b.pack)
t->size = ALIGNUP(t->size, t->align);
break;
case TYPEENUM:
enumconsts = NULL;
if (et) {
t->size = t->base->size;
t->align = t->base->align;
t->u.basic.issigned = t->base->u.basic.issigned;
t->incomplete = false;
et = t;
} else {
et = &typeint;
}
max = 0;
min = 0;
for (value = 0; tok.kind == TIDENT; ++value) {
name = tok.lit;
next();
attr(NULL, 0);
if (consume(TASSIGN)) {
e = eval(condexpr(s));
if (e->kind != EXPRCONST || !(e->type->prop & PROPINT))
error(&tok.loc, "expected integer constant expression");
value = e->u.constant.u;
if (!t->base)
et = typehasint(&typeint, value, e->type->u.basic.issigned) ? &typeint : e->type;
else if (!typehasint(et, value, e->type->u.basic.issigned))
goto invalid;
} else if (value == 0 && !et->u.basic.issigned || value == 1ull << 63 && et->u.basic.issigned) {
error(&tok.loc, "no %ssigned integer type can represent enumerator value", et->u.basic.issigned ? "" : "un");
} else if (!typehasint(et, value, et->u.basic.issigned)) {
if (t->base) {
invalid:
/* fixed underlying type */
error(&tok.loc, "enumerator '%s' value cannot be represented in underlying type", name);
}
sign = et->u.basic.issigned;
for (i = 0; i < LEN(inttypes); ++i) {
et = inttypes[i][sign];
if (typehasint(et, value, sign))
break;
}
assert(i < LEN(inttypes));
}
d = mkdecl(name, DECLCONST, et, QUALNONE, LINKNONE);
d->u.enumconst = value;
d->value = mkintconst(value);
d->next = enumconsts;
enumconsts = d;
if (et->u.basic.issigned && value >= 1ull << 63) {
if (-value > min)
min = -value;
} else if (value > max) {
max = value;
}
scopeputdecl(s, d);
if (!consume(TCOMMA))
break;
}
expect(TRBRACE, "to close enum specifier");
if (!t->base) {
if (min <= 0x80000000 && max <= 0x7fffffff) {
t->base = min ? &typeint : &typeuint;
} else {
sign = min > 0;
for (i = 0; i < LEN(inttypes); ++i) {
et = inttypes[i][sign];
if (typehasint(et, max, false) && typehasint(et, -min, true))
break;
}
if (i == LEN(inttypes))
error(&tok.loc, "no integer type can represent all enumerator values");
t->base = et;
for (d = enumconsts; d; d = d->next)
d->type = t;
}
t->size = t->base->size;
t->align = t->base->align;
t->u.basic.issigned = t->base->u.basic.issigned;
}
}
t->incomplete = false;
return t;
}
/* 6.7 Declarations */
static struct qualtype
declspecs(struct scope *s, enum storageclass *sc, enum funcspec *fs, int *align)
{
struct type *t, *other;
struct decl *d;
struct expr *e;
enum typespec ts = SPECNONE;
enum typequal tq = QUALNONE;
enum tokenkind op;
int ntypes = 0;
unsigned long long i;
struct expr *typeofexpr = NULL;
t = NULL;
if (sc)
*sc = SCNONE;
if (fs)
*fs = FUNCNONE;
if (align)
*align = 0;
for (;;) {
if (typequal(&tq) || storageclass(sc) || funcspec(fs))
continue;
op = tok.kind;
switch (op) {
/* 6.7.2 Type specifiers */
case TVOID:
t = &typevoid;
++ntypes;
next();
break;
case TCHAR:
ts |= SPECCHAR;
++ntypes;
next();
break;
case TSHORT:
if (ts & SPECSHORT)
error(&tok.loc, "duplicate 'short'");
ts |= SPECSHORT;
next();
break;
case TINT:
ts |= SPECINT;
++ntypes;
next();
break;
case TLONG:
if (ts & SPECLONG2)
error(&tok.loc, "too many 'long'");
if (ts & SPECLONG)
ts |= SPECLONG2;
ts |= SPECLONG;
next();
break;
case TFLOAT:
ts |= SPECFLOAT;
++ntypes;
next();
break;
case TDOUBLE:
ts |= SPECDOUBLE;
++ntypes;
next();
break;
case TSIGNED:
if (ts & SPECSIGNED)
error(&tok.loc, "duplicate 'signed'");
ts |= SPECSIGNED;
next();
break;
case TUNSIGNED:
if (ts & SPECUNSIGNED)
error(&tok.loc, "duplicate 'unsigned'");
ts |= SPECUNSIGNED;
next();
break;
case TBOOL:
t = &typebool;
++ntypes;
next();
break;
case T_COMPLEX:
error(&tok.loc, "_Complex is not yet supported");
break;
case T_ATOMIC:
error(&tok.loc, "_Atomic is not yet supported");
break;
case TSTRUCT:
case TUNION:
case TENUM:
t = tagspec(s);
++ntypes;
break;
case TIDENT:
if (t || ts)
goto done;
d = scopegetdecl(s, tok.lit, 1);
if (!d || d->kind != DECLTYPE)
goto done;
t = d->type;
tq |= d->qual;
++ntypes;
next();
break;
case TTYPEOF:
case TTYPEOF_UNQUAL:
next();
expect(TLPAREN, "after 'typeof'");
t = typename(s, &tq, &typeofexpr);
if (!t) {
e = expr(s);
if (e->decayed)
e = e->base;
t = e->type;
if (op == TTYPEOF)
tq |= e->qual;
if (t->prop & PROPVM)
typeofexpr = e;
}
++ntypes;
expect(TRPAREN, "to close 'typeof'");
break;
/* 6.7.5 Alignment specifier */
case TALIGNAS:
if (!align)
error(&tok.loc, "alignment specifier not allowed in this declaration");
next();
expect(TLPAREN, "after 'alignas'");
other = typename(s, NULL, NULL);
i = other ? other->align : intconstexpr(s, false);
if (i & i - 1 || i > INT_MAX)
error(&tok.loc, "invalid alignment: %llu", i);
if (i > *align)
*align = i;
expect(TRPAREN, "to close 'alignas' specifier");
break;
case T__ATTRIBUTE__:
gnuattr(NULL, 0);
break;
default:
goto done;
}
if (ntypes > 1 || (t && ts))
error(&tok.loc, "multiple types in declaration specifiers");
}
done:
switch ((int)ts) {
case SPECNONE: break;
case SPECCHAR: t = &typechar; break;
case SPECSIGNED|SPECCHAR: t = &typeschar; break;
case SPECUNSIGNED|SPECCHAR: t = &typeuchar; break;
case SPECSHORT:
case SPECSHORT|SPECINT:
case SPECSIGNED|SPECSHORT:
case SPECSIGNED|SPECSHORT|SPECINT: t = &typeshort; break;
case SPECUNSIGNED|SPECSHORT:
case SPECUNSIGNED|SPECSHORT|SPECINT: t = &typeushort; break;
case SPECINT:
case SPECSIGNED:
case SPECSIGNED|SPECINT: t = &typeint; break;
case SPECUNSIGNED:
case SPECUNSIGNED|SPECINT: t = &typeuint; break;
case SPECLONG:
case SPECLONG|SPECINT:
case SPECSIGNED|SPECLONG:
case SPECSIGNED|SPECLONG|SPECINT: t = &typelong; break;
case SPECUNSIGNED|SPECLONG:
case SPECUNSIGNED|SPECLONG|SPECINT: t = &typeulong; break;
case SPECLONGLONG:
case SPECLONGLONG|SPECINT:
case SPECSIGNED|SPECLONGLONG:
case SPECSIGNED|SPECLONGLONG|SPECINT: t = &typellong; break;
case SPECUNSIGNED|SPECLONGLONG:
case SPECUNSIGNED|SPECLONGLONG|SPECINT: t = &typeullong; break;
case SPECFLOAT: t = &typefloat; break;
case SPECDOUBLE: t = &typedouble; break;
case SPECLONG|SPECDOUBLE: t = &typeldouble; break;
default:
error(&tok.loc, "invalid combination of type specifiers");
}
if (!t && (tq || sc && *sc || fs && *fs))
error(&tok.loc, "declaration has no type specifier");
/*
TODO: consider delaying attribute parsing to declarator(),
so we can tell the difference between the start of an
attribute and an array declarator.
*/
attr(NULL, 0);
return (struct qualtype){t, tq, typeofexpr};
}
/* 6.7.6 Declarators */
static struct decl *parameter(struct scope *);
static bool
istypename(struct scope *s, const char *name)
{
struct decl *d;
d = scopegetdecl(s, name, 1);
return d && d->kind == DECLTYPE;
}
/*
When parsing a declarator, qualifiers for derived types are temporarily
stored in the `qual` field of the type itself (elsewhere this field
is used for the qualifiers of the base type). This is corrected in
declarator().
*/
static void
declaratortypes(struct scope *s, struct list *result, char **name, struct scope **funcscope, bool allowabstract)
{
struct list *ptr, *prev;
struct type *t;
struct decl *d, **paramend;
struct expr *e;
enum typequal tq;
bool allowattr;
while (consume(TMUL)) {
attr(NULL, 0);
tq = QUALNONE;
while (typequal(&tq))
;
t = mkpointertype(NULL, tq);
listinsert(result, &t->link);
}
if (name)
*name = NULL;
ptr = result->next;
prev = ptr->prev;
switch (tok.kind) {
case TLPAREN:
next();
if (allowabstract) {
switch (tok.kind) {
case TMUL:
case TLPAREN:
break;
case TIDENT:
if (!istypename(s, tok.lit))
break;
/* fallthrough */
default:
allowattr = true;
goto func;
}
}
declaratortypes(s, result, name, funcscope, allowabstract);
expect(TRPAREN, "after parenthesized declarator");
allowattr = false;
break;
case TIDENT:
if (!name)
error(&tok.loc, "identifier not allowed in abstract declarator");
*name = tok.lit;
next();
allowattr = true;
break;
default:
if (!allowabstract)
error(&tok.loc, "expected '(' or identifier");
allowattr = true;
}
for (;;) {
switch (tok.kind) {
case TLPAREN: /* function declarator */
next();
func:
t = mktype(TYPEFUNC, 0);
t->qual = QUALNONE;
t->u.func.isvararg = false;
t->u.func.params = NULL;
t->u.func.nparam = 0;
paramend = &t->u.func.params;
s = mkscope(s);
d = NULL;
do {
if (consume(TELLIPSIS)) {
t->u.func.isvararg = true;
break;
}
if (tok.kind == TRPAREN)
break;
d = parameter(s);
if (d->name)
scopeputdecl(s, d);
*paramend = d;
paramend = &d->next;
++t->u.func.nparam;
} while (consume(TCOMMA));
expect(TRPAREN, "to close function declarator");
if (funcscope && ptr->prev == prev) {
/* we may need to re-open the scope later if this is a function definition */
*funcscope = s;
s = s->parent;
} else {
s = delscope(s);
}
if (t->u.func.nparam == 1 && !t->u.func.isvararg && d->type->kind == TYPEVOID && !d->name) {
t->u.func.params = NULL;
t->u.func.nparam = 0;
}
listinsert(ptr->prev, &t->link);
allowattr = true;
break;
case TLBRACK: /* array declarator */
if (allowattr && attr(NULL, 0))
goto attr;
next();
t = mkarraytype(NULL, QUALNONE, 0);
while (consume(TSTATIC) || typequal(&t->u.array.ptrqual))
;
if (tok.kind == TMUL && peek(TRBRACK)) {
t->prop |= PROPVM;
t->incomplete = false;
} else if (!consume(TRBRACK)) {
e = assignexpr(s);
if (!(e->type->prop & PROPINT))
error(&tok.loc, "array length expression must have integer type");
t->u.array.length = e;
t->incomplete = false;
expect(TRBRACK, "after array length");
}
listinsert(ptr->prev, &t->link);
allowattr = true;
break;
case T__ATTRIBUTE__:
if (!allowattr)
error(&tok.loc, "attribute not allowed after parenthesized declarator");
/* attribute applies to identifier if ptr->prev == result, otherwise type ptr->prev */
gnuattr(NULL, 0);
attr:
break;
default:
return;
}
}
}
static struct qualtype
declarator(struct scope *s, struct qualtype base, char **name, struct scope **funcscope, bool allowabstract)
{
struct type *t;
enum typequal tq;
struct expr *e;
struct list result = {&result, &result}, *l, *prev;
if (funcscope)
*funcscope = NULL;
declaratortypes(s, &result, name, funcscope, allowabstract);
for (l = result.prev; l != &result; l = prev) {
prev = l->prev;
t = listelement(l, struct type, link);
tq = t->qual;
t->base = base.type;
t->qual = base.qual;
t->prop |= base.type->prop & PROPVM;
switch (t->kind) {
case TYPEFUNC:
if (base.type->kind == TYPEFUNC)
error(&tok.loc, "function declarator specifies function return type");
if (base.type->kind == TYPEARRAY)
error(&tok.loc, "function declarator specifies array return type");
break;
case TYPEARRAY:
if (base.type->incomplete)
error(&tok.loc, "array element has incomplete type");
if (base.type->kind == TYPEFUNC)
error(&tok.loc, "array element has function type");
t->align = base.type->align;
t->size = 0;
if (t->u.array.length) {
e = eval(t->u.array.length);
if (e->kind == EXPRCONST) {
if (e->type->u.basic.issigned && e->u.constant.u >> 63)
error(&tok.loc, "array length must be non-negative");
if (e->u.constant.u > ULLONG_MAX / base.type->size)
error(&tok.loc, "array length is too large");
t->size = base.type->size * e->u.constant.u;
} else {
t->prop |= PROPVM;
t->u.array.length = e;
t->u.array.size = NULL;
}
}
break;
}
base.type = t;
base.qual = tq;
}
return base;
}
static struct decl *
parameter(struct scope *s)
{
struct decl *d;
char *name;
struct qualtype t;
enum storageclass sc;
attr(NULL, 0);
t = declspecs(s, &sc, NULL, NULL);
if (!t.type)
error(&tok.loc, "no type in parameter declaration");
if (sc && sc != SCREGISTER)
error(&tok.loc, "parameter declaration has invalid storage-class specifier");
t = declarator(s, t, &name, NULL, true);
t.type = typeadjust(t.type, &t.qual);
d = mkdecl(name, DECLOBJECT, t.type, t.qual, LINKNONE);
d->u.obj.storage = SDAUTO;
return d;
}
static void
addmember(struct structbuilder *b, struct qualtype mt, char *name, int align, unsigned long long width)
{
struct type *t = b->type;
struct member *m;
size_t end;
if (t->flexible)
error(&tok.loc, "struct has member '%s' after flexible array member", name);
if (mt.type->incomplete) {
if (mt.type->kind != TYPEARRAY)
error(&tok.loc, "struct member '%s' has incomplete type", name);
t->flexible = true;
}
if (mt.type->kind == TYPEFUNC)
error(&tok.loc, "struct member '%s' has function type", name);
if (mt.type->prop & PROPVM)
error(&tok.loc, "struct member '%s' has variably modified type", name);
if (mt.type->flexible)
error(&tok.loc, "struct member '%s' contains flexible array member", name);
assert(mt.type->align > 0);
if (name || width == -1) {
m = xmalloc(sizeof(*m));
m->type = mt.type;
m->qual = mt.qual;
m->name = name;
m->next = NULL;
*b->last = m;
b->last = &m->next;
} else {
m = NULL;
}
if (width == -1) {
m->bits.before = 0;
m->bits.after = 0;
if (align < mt.type->align) {
if (align)
error(&tok.loc, "specified alignment of struct member '%s' is less strict than is required by type", name);
align = b->pack ? 1 : mt.type->align;
}
if (t->kind == TYPESTRUCT) {
m->offset = ALIGNUP(t->size, align);
t->size = m->offset + mt.type->size;
} else {
m->offset = 0;
if (t->size < mt.type->size)
t->size = mt.type->size;
}
b->bits = 0;
} else { /* bit-field */
if (!(mt.type->prop & PROPINT))
error(&tok.loc, "bit-field '%s' has invalid type", name);
if (align)
error(&tok.loc, "alignment specified for bit-field '%s'", name);
if (b->pack)
error(&tok.loc, "bit-field '%s' in packed struct is not supported", name);
if (!width && name)
error(&tok.loc, "bit-field '%s' with zero width must not have declarator", name);
if (width > mt.type->size * 8)
error(&tok.loc, "bit-field '%s' exceeds width of underlying type", name);
align = mt.type->align;
if (t->kind == TYPESTRUCT) {
/* calculate end of the storage-unit for this bit-field */
end = ALIGNUP(t->size, mt.type->size);
if (!width || width > (end - t->size) * 8 + b->bits) {
/* no room, allocate a new storage-unit */
t->size = end;
b->bits = 0;
}
if (m) {
m->offset = ALIGNDOWN(t->size - !!b->bits, mt.type->size);
m->bits.before = (t->size - m->offset) * 8 - b->bits;
m->bits.after = mt.type->size * 8 - width - m->bits.before;
}
t->size += (width - b->bits + 7) / 8;
b->bits = (b->bits - width) % 8;
} else if (m) {
m->offset = 0;
m->bits.before = 0;
m->bits.after = mt.type->size * 8 - width;
if (t->size < mt.type->size)
t->size = mt.type->size;
}
}
if (m && t->align < align)
t->align = align;
}
static bool
staticassert(struct scope *s)
{
struct stringlit msg;
unsigned long long c;
if (!consume(TSTATIC_ASSERT))
return false;
expect(TLPAREN, "after static_assert");
c = intconstexpr(s, true);
if (consume(TCOMMA)) {
tokencheck(&tok, TSTRINGLIT, "after static assertion expression");
stringconcat(&msg, true);
if (!c)
error(&tok.loc, "static assertion failed: %.*s", (int)(msg.size - 1), (char *)msg.data);
} else if (!c) {
error(&tok.loc, "static assertion failed");
}
expect(TRPAREN, "after static assertion");
expect(TSEMICOLON, "after static assertion");
return true;
}
static void
structdecl(struct scope *s, struct structbuilder *b)
{
struct qualtype base, mt;
char *name;
unsigned long long width;
int align;
if (staticassert(s))
return;
attr(NULL, 0);
base = declspecs(s, NULL, NULL, &align);
if (!base.type)
error(&tok.loc, "no type in struct member declaration");
if (tok.kind == TSEMICOLON) {
if ((base.type->kind != TYPESTRUCT && base.type->kind != TYPEUNION) || base.type->u.structunion.tag)
error(&tok.loc, "struct declaration must declare at least one member");
next();
addmember(b, base, NULL, align, -1);
return;
}
for (;;) {
if (consume(TCOLON)) {
width = intconstexpr(s, false);
addmember(b, base, NULL, 0, width);
} else {
mt = declarator(s, base, &name, NULL, false);
width = consume(TCOLON) ? intconstexpr(s, false) : -1;
addmember(b, mt, name, align, width);
}
if (tok.kind == TSEMICOLON)
break;
expect(TCOMMA, "or ';' after declarator");
}
next();
}
/* 6.7.7 Type names */
struct type *
typename(struct scope *s, enum typequal *tq, struct expr **toeval)
{
struct qualtype t;
t = declspecs(s, NULL, NULL, NULL);
if (t.type) {
t = declarator(s, t, NULL, NULL, true);
if (tq)
*tq |= t.qual;
if (toeval)
*toeval = t.expr;
}
return t.type;
}
static enum linkage
getlinkage(enum declkind kind, enum storageclass sc, struct decl *prior, bool filescope)
{
if (sc & SCSTATIC)
return filescope ? LINKINTERN : LINKNONE;
if (sc & SCEXTERN || kind == DECLFUNC)
return prior ? prior->linkage : LINKEXTERN;
return filescope ? LINKEXTERN : LINKNONE;
}
static struct decl *
declcommon(struct scope *s, enum declkind kind, char *name, char *asmname, struct type *t, enum typequal tq, enum storageclass sc, struct decl *prior)
{
struct decl *d;
enum linkage linkage;
const char *kindstr = kind == DECLFUNC ? "function" : "object";
if (prior) {
if (prior->linkage == LINKNONE)
error(&tok.loc, "%s '%s' with no linkage redeclared", kindstr, name);
linkage = getlinkage(kind, sc, prior, s == &filescope);
if (prior->linkage != linkage)
error(&tok.loc, "%s '%s' redeclared with different linkage", kindstr, name);
if (!typecompatible(t, prior->type) || tq != prior->qual)
error(&tok.loc, "%s '%s' redeclared with incompatible type", kindstr, name);
if (asmname && (!prior->asmname || strcmp(prior->asmname, asmname) != 0))
error(&tok.loc, "%s '%s' redeclared with different assembler name", kindstr, name);
prior->type = typecomposite(t, prior->type);
return prior;
}
if (s->parent)
prior = scopegetdecl(s->parent, name, true);
linkage = getlinkage(kind, sc, prior, s == &filescope);
if (linkage != LINKNONE && s->parent) {
/* XXX: should maintain map of identifiers with linkage to their declaration, and use that */
if (s->parent != &filescope)
prior = scopegetdecl(&filescope, name, false);
if (prior && prior->linkage != LINKNONE) {
if (prior->kind != kind)
error(&tok.loc, "'%s' redeclared with different kind", name);
if (prior->linkage != linkage)
error(&tok.loc, "%s '%s' redeclared with different linkage", kindstr, name);
if (!typecompatible(t, prior->type) || tq != prior->qual)
error(&tok.loc, "%s '%s' redeclared with incompatible type", kindstr, name);
if (!asmname)
asmname = prior->asmname;
else if (!prior->asmname || strcmp(prior->asmname, asmname) != 0)
error(&tok.loc, "%s '%s' redeclared with different assembler name", kindstr, name);
t = typecomposite(t, prior->type);
}
}
d = mkdecl(name, kind, t, tq, linkage);
d->asmname = asmname;
scopeputdecl(s, d);
return d;
}
bool
decl(struct scope *s, struct func *f)
{
struct qualtype base, qt;
struct type *t;
enum typequal tq;
enum storageclass sc;
enum funcspec fs;
struct init *init;
bool hasinit;
char *name, *asmname;
int allowfunc = !f;
struct decl *d, *prior;
enum declkind kind;
struct scope *funcscope;
int align;
if (staticassert(s))
return true;
if (attr(NULL, 0) && consume(TSEMICOLON))
return true;
base = declspecs(s, &sc, &fs, &align);
if (!base.type)
return false;
if (f) {
if (sc == SCTHREADLOCAL)
error(&tok.loc, "block scope declaration containing 'thread_local' must contain 'static' or 'extern'");
} else {
/* 6.9p2 */
if (sc & SCAUTO)
error(&tok.loc, "external declaration must not contain 'auto'");
if (sc & SCREGISTER)
error(&tok.loc, "external declaration must not contain 'register'");
}
if (consume(TSEMICOLON)) {
/* XXX 6.7p2 error unless in function parameter/struct/union, or tag/enum members are declared */
return true;
}
for (;;) {