#include "c.h"

static char rcsid[] = "$Id: decl.c,v 1.1 2002/08/28 23:12:42 drh Exp $";

#define add(x,n) (x > inttype->u.sym->u.limits.max.i-(n) ? (overflow=1,x) : x+(n))
#define chkoverflow(x,n) ((void)add(x,n))
#define bits2bytes(n) (((n) + 7)/8)
static int regcount;

static List autos, registers;
Symbol cfunc;        /* current function */
Symbol retv;        /* return value location for structs */

static void checkref(Symbol, void *);
static Symbol dclglobal(int, char *, Type, Coordinate *);
static Symbol dcllocal(int, char *, Type, Coordinate *);
static Symbol dclparam(int, char *, Type, Coordinate *);
static Type dclr(Type, char **, Symbol **, int);
static Type dclr1(char **, Symbol **, int);
static void decl(Symbol (*)(int, char *, Type, Coordinate *));
extern void doconst(Symbol, void *);
static void doglobal(Symbol, void *);
static void doextern(Symbol, void *);
static void exitparams(Symbol []);
static void fields(Type);
static void funcdefn(int, char *, Type, Symbol [], Coordinate);
static void initglobal(Symbol, int);
static void oldparam(Symbol, void *);
static Symbol *parameters(Type);
static Type specifier(int *);
static Type structdcl(int);
static Type tnode(int, Type);
void program(void) {
    int n;

    level = GLOBAL;
    for (n = 0; t != EOI; n++){

        if (kind[t] == CHAR || kind[t] == STATIC
        || t == ID || t == '*' || t == '(') {
            decl(dclglobal);
            deallocate(STMT);
            if (!(glevel >= 3 || xref))
            	deallocate(FUNC);
        } else if (t == ';') {
            warning("empty declaration\n");
            t = gettok();
        } else {
            error("unrecognized declaration\n");
            t = gettok();
        }

    }
    if (n == 0)
        warning("empty input file\n");
}
static Type specifier(int *sclass) {
    int cls, cons, sign, size, type, vol;
    Type ty = NULL;

    cls = vol = cons = sign = size = type = 0;
    if (sclass == NULL)
        cls = AUTO;
    for (;;) {
        int *p, tt = t;
        switch (t) {
        case AUTO:
        case REGISTER: if (level <= GLOBAL && cls == 0)
                           error("invalid use of `%k'\n", t);
                       p = &cls;  t = gettok();      break;
        case STATIC: case EXTERN:
        case TYPEDEF:  p = &cls;  t = gettok();      break;
        case CONST:    p = &cons; t = gettok();      break;
        case VOLATILE: p = &vol;  t = gettok();      break;
        case SIGNED:
        case UNSIGNED: p = &sign; t = gettok();      break;
        case LONG:     if (size == LONG) {
                               size = 0;
                               tt = LONG+LONG;
                       }
                       p = &size; t = gettok();      break;
        case SHORT:    p = &size; t = gettok();      break;
        case VOID: case CHAR: case INT: case FLOAT:
        case DOUBLE:   p = &type; ty = tsym->type;
                                  t = gettok();      break;
        case ENUM:     p = &type; ty = enumdcl();    break;
        case STRUCT:
        case UNION:    p = &type; ty = structdcl(t); break;
        case ID:
            if (istypename(t, tsym) && type == 0
            && sign == 0 && size == 0) {
                use(tsym, src);
                ty = tsym->type;
                if (isqual(ty)
                && ty->size != ty->type->size) {
                    ty = unqual(ty);
                    if (isconst(tsym->type))
                        ty = qual(CONST, ty);
                    if (isvolatile(tsym->type))
                        ty = qual(VOLATILE, ty);
                    tsym->type = ty;
                }
                p = &type;
                t = gettok();
            } else
                p = NULL;
            break;
        default: p = NULL;
        }
        if (p == NULL)
            break;
        if (*p)
            error("invalid use of `%k'\n", tt);
        *p = tt;
    }
    if (sclass)
        *sclass = cls;
    if (type == 0) {
        type = INT;
        ty = inttype;
    }
    if (size == SHORT     && type != INT
    ||  size == LONG+LONG && type != INT
    ||  size == LONG      && type != INT && type != DOUBLE
    ||  sign && type != INT && type != CHAR)
        error("invalid type specification\n");
    if (type == CHAR && sign)
        ty = sign == UNSIGNED ? unsignedchar : signedchar;
    else if (size == SHORT)
        ty = sign == UNSIGNED ? unsignedshort : shorttype;
    else if (size == LONG && type == DOUBLE)
        ty = longdouble;
    else if (size == LONG+LONG) {
        ty = sign == UNSIGNED ? unsignedlonglong : longlong;
        if (Aflag >= 1)
            warning("`%t' is a non-ANSI type\n", ty);
    } else if (size == LONG)
        ty = sign == UNSIGNED ? unsignedlong : longtype;
    else if (sign == UNSIGNED && type == INT)
        ty = unsignedtype;
    if (cons == CONST)
        ty = qual(CONST, ty);
    if (vol  == VOLATILE)
        ty = qual(VOLATILE, ty);
    return ty;
}
static void decl(Symbol (*dcl)(int, char *, Type, Coordinate *)) {
    int sclass;
    Type ty, ty1;
    static char stop[] = { CHAR, STATIC, ID, 0 };

    ty = specifier(&sclass);
    if (t == ID || t == '*' || t == '(' || t == '[') {
        char *id;
        Coordinate pos;
        id = NULL;
        pos = src;
        if (level == GLOBAL) {
            Symbol *params = NULL;
            ty1 = dclr(ty, &id, &params, 0);
            if (params && id && isfunc(ty1)
                && (t == '{' || istypename(t, tsym)
                || (kind[t] == STATIC && t != TYPEDEF))) {
                if (sclass == TYPEDEF) {
                    error("invalid use of `typedef'\n");
                    sclass = EXTERN;
                }
                if (ty1->u.f.oldstyle)
                    exitscope();
                funcdefn(sclass, id, ty1, params, pos);
                return;
            } else if (params)
                exitparams(params);
        } else
            ty1 = dclr(ty, &id, NULL, 0);
        for (;;) {
            if (Aflag >= 1 && !hasproto(ty1))
                warning("missing prototype\n");
            if (id == NULL)
                error("missing identifier\n");
            else if (sclass == TYPEDEF)
                {
                    Symbol p = lookup(id, identifiers);
                    if (p && p->scope == level)
                        error("redeclaration of `%s'\n", id);
                    p = install(id, &identifiers, level,
                        level < LOCAL ? PERM : FUNC);
                    p->type = ty1;
                    p->sclass = TYPEDEF;
                    p->src = pos;
                }
            else
                (void)(*dcl)(sclass, id, ty1, &pos);
            if (t != ',')
                break;
            t = gettok();
            id = NULL;
            pos = src;
            ty1 = dclr(ty, &id, NULL, 0);
        }
    } else if (ty == NULL
    || !(isenum(ty) ||
         isstruct(ty) && (*unqual(ty)->u.sym->name < '1' || *unqual(ty)->u.sym->name > '9')))
        error("empty declaration\n");
    test(';', stop);

}
static Symbol dclglobal(int sclass, char *id, Type ty, Coordinate *pos) {
    Symbol p;

    if (sclass == 0)
        sclass = AUTO;
    else if (sclass != EXTERN && sclass != STATIC) {
        error("invalid storage class `%k' for `%t %s'\n",
            sclass, ty, id);
        sclass = AUTO;
    }
    p = lookup(id, identifiers);
    if (p && p->scope == GLOBAL) {
        if (p->sclass != TYPEDEF && eqtype(ty, p->type, 1))
            ty = compose(ty, p->type);
        else
            error("redeclaration of `%s' previously declared at %w\n", p->name, &p->src);

        if (!isfunc(ty) && p->defined && t == '=')
            error("redefinition of `%s' previously defined at %w\n", p->name, &p->src);

        if (p->sclass == EXTERN && sclass == STATIC
        ||  p->sclass == STATIC && sclass == AUTO
        ||  p->sclass == AUTO   && sclass == STATIC)
            warning("inconsistent linkage for `%s' previously declared at %w\n", p->name, &p->src);

    }
    if (p == NULL || p->scope != GLOBAL) {
        Symbol q = lookup(id, externals);
        if (q) {
            if (sclass == STATIC || !eqtype(ty, q->type, 1))
                warning("declaration of `%s' does not match previous declaration at %w\n", id, &q->src);

            p = relocate(id, externals, globals);
            p->sclass = sclass;
        } else {
            p = install(id, &globals, GLOBAL, PERM);
            p->sclass = sclass;
            (*IR->defsymbol)(p);
        }
        if (p->sclass != STATIC) {
            static int nglobals;
            nglobals++;
            if (Aflag >= 2 && nglobals == 512)
                warning("more than 511 external identifiers\n");
        }
    } else if (p->sclass == EXTERN)
        p->sclass = sclass;
    p->type = ty;
    p->src = *pos;
    if (t == '=' && isfunc(p->type)) {
        error("illegal initialization for `%s'\n", p->name);
        t = gettok();
        initializer(p->type, 0);
    } else if (t == '=') {
        initglobal(p, 0);
        if (glevel > 0 && IR->stabsym) {
            (*IR->stabsym)(p); swtoseg(p->u.seg); }
    } else if (p->sclass == STATIC && !isfunc(p->type)
    && p->type->size == 0)
        error("undefined size for `%t %s'\n", p->type, p->name);
    return p;
}
static void initglobal(Symbol p, int flag) {
    Type ty;

    if (t == '=' || flag) {
        if (p->sclass == STATIC) {
            for (ty = p->type; isarray(ty); ty = ty->type)
                ;
            defglobal(p, isconst(ty) ? LIT : DATA);
        } else
            defglobal(p, DATA);
        if (t == '=')
            t = gettok();
        ty = initializer(p->type, 0);
        if (isarray(p->type) && p->type->size == 0)
            p->type = ty;
        if (p->sclass == EXTERN)
            p->sclass = AUTO;
    }
}
void defglobal(Symbol p, int seg) {
    p->u.seg = seg;
    swtoseg(p->u.seg);
    if (p->sclass != STATIC)
        (*IR->export)(p);
    (*IR->global)(p);
    p->defined = 1;
}

static Type dclr(Type basety, char **id, Symbol **params, int abstract) {
    Type ty = dclr1(id, params, abstract);

    for ( ; ty; ty = ty->type)
        switch (ty->op) {
        case POINTER:
            basety = ptr(basety);
            break;
        case FUNCTION:
            basety = func(basety, ty->u.f.proto,
                ty->u.f.oldstyle);
            break;
        case ARRAY:
            basety = array(basety, ty->size, 0);
            break;
        case CONST: case VOLATILE:
            basety = qual(ty->op, basety);
            break;
        default: assert(0);
        }
    if (Aflag >= 2 && basety->size > 32767)
        warning("more than 32767 bytes in `%t'\n", basety);
    return basety;
}
static Type tnode(int op, Type type) {
    Type ty;

    NEW0(ty, STMT);
    ty->op = op;
    ty->type = type;
    return ty;
}
static Type dclr1(char **id, Symbol **params, int abstract) {
    Type ty = NULL;

    switch (t) {
    case ID:                if (id)
                    *id = token;
                else
                    error("extraneous identifier `%s'\n", token);
                t = gettok(); break;
    case '*': t = gettok(); if (t == CONST || t == VOLATILE) {
                    Type ty1;
                    ty1 = ty = tnode(t, NULL);
                    while ((t = gettok()) == CONST || t == VOLATILE)
                        ty1 = tnode(t, ty1);
                    ty->type = dclr1(id, params, abstract);
                    ty = ty1;
                } else
                    ty = dclr1(id, params, abstract);
                ty = tnode(POINTER, ty); break;
    case '(': t = gettok(); if (abstract
                && (t == REGISTER || istypename(t, tsym) || t == ')')) {
                    Symbol *args;
                    ty = tnode(FUNCTION, ty);
                    enterscope();
                    if (level > PARAM)
                        enterscope();
                    args = parameters(ty);
                    exitparams(args);
                } else {
                    ty = dclr1(id, params, abstract);
                    expect(')');
                    if (abstract && ty == NULL
                    && (id == NULL || *id == NULL))
                        return tnode(FUNCTION, NULL);
                } break;
    case '[': break;
    default:  return ty;
    }
    while (t == '(' || t == '[')
        switch (t) {
        case '(': t = gettok(); { Symbol *args;
                      ty = tnode(FUNCTION, ty);
                      enterscope();
                      if (level > PARAM)
                          enterscope();
                      args = parameters(ty);
                      if (params && *params == NULL)
                          *params = args;
                      else
                          exitparams(args);
 }
                  break;
        case '[': t = gettok(); { int n = 0;
                      if (kind[t] == ID) {
                          n = intexpr(']', 1);
                          if (n <= 0) {
                              error("`%d' is an illegal array size\n", n);
                              n = 1;
                          }
                      } else
                          expect(']');
                      ty = tnode(ARRAY, ty);
                      ty->size = n; } break;
        default: assert(0);
        }
    return ty;
}
static Symbol *parameters(Type fty) {
    List list = NULL;
    Symbol *params;

    if (kind[t] == STATIC || istypename(t, tsym)) {
        int n = 0;
        Type ty1 = NULL;
        for (;;) {
            Type ty;
            int sclass = 0;
            char *id = NULL;
            if (ty1 && t == ELLIPSIS) {
                static struct symbol sentinel;
                if (sentinel.type == NULL) {
                    sentinel.type = voidtype;
                    sentinel.defined = 1;
                }
                if (ty1 == voidtype)
                    error("illegal formal parameter types\n");
                list = append(&sentinel, list);
                t = gettok();
                break;
            }
            if (!istypename(t, tsym) && t != REGISTER)
                error("missing parameter type\n");
            n++;
            ty = dclr(specifier(&sclass), &id, NULL, 1);
            if ( ty == voidtype && (ty1 || id)
            ||  ty1 == voidtype)
                error("illegal formal parameter types\n");
            if (id == NULL)
                id = stringd(n);
            if (ty != voidtype)
                list = append(dclparam(sclass, id, ty, &src), list);
            if (Aflag >= 1 && !hasproto(ty))
                warning("missing prototype\n");
            if (ty1 == NULL)
                ty1 = ty;
            if (t != ',')
                break;
            t = gettok();
        }
        fty->u.f.proto = newarray(length(list) + 1,
            sizeof (Type *), PERM);
        params = ltov(&list, FUNC);
        for (n = 0; params[n]; n++)
            fty->u.f.proto[n] = params[n]->type;
        fty->u.f.proto[n] = NULL;
        fty->u.f.oldstyle = 0;
    } else {
        if (t == ID)
            for (;;) {
                Symbol p;
                if (t != ID) {
                    error("expecting an identifier\n");
                    break;
                }
                p = dclparam(0, token, inttype, &src);
                p->defined = 0;
                list = append(p, list);
                t = gettok();
                if (t != ',')
                    break;
                t = gettok();
            }
        params = ltov(&list, FUNC);
        fty->u.f.proto = NULL;
        fty->u.f.oldstyle = 1;
    }
    if (t != ')') {
        static char stop[] = { CHAR, STATIC, IF, ')', 0 };
        expect(')');
        skipto('{', stop);
    }
    if (t == ')')
        t = gettok();
    return params;
}
static void exitparams(Symbol params[]) {
    assert(params);
    if (params[0] && !params[0]->defined)
        error("extraneous old-style parameter list\n");
    if (level > PARAM)
        exitscope();
    exitscope();
}

static Symbol dclparam(int sclass, char *id, Type ty, Coordinate *pos) {
    Symbol p;

    if (isfunc(ty))
        ty = ptr(ty);
    else if (isarray(ty))
        ty = atop(ty);
    if (sclass == 0)
        sclass = AUTO;
    else if (sclass != REGISTER) {
        error("invalid storage class `%k' for `%t%s\n",
            sclass, ty, stringf(id ? " %s'" : "' parameter", id));
        sclass = AUTO;
    } else if (isvolatile(ty) || isstruct(ty)) {
        warning("register declaration ignored for `%t%s\n",
            ty, stringf(id ? " %s'" : "' parameter", id));
        sclass = AUTO;
    }

    p = lookup(id, identifiers);
    if (p && p->scope == level)
        error("duplicate declaration for `%s' previously declared at %w\n", id, &p->src);

    else
        p = install(id, &identifiers, level, FUNC);
    p->sclass = sclass;
    p->src = *pos;
    p->type = ty;
    p->defined = 1;
    if (t == '=') {
        error("illegal initialization for parameter `%s'\n", id);
        t = gettok();
        (void)expr1(0);
    }
    return p;
}
static Type structdcl(int op) {
    char *tag;
    Type ty;
    Symbol p;
    Coordinate pos;

    t = gettok();
    pos = src;
    if (t == ID) {
        tag = token;
        t = gettok();
    } else
        tag = "";
    if (t == '{') {
        static char stop[] = { IF, ',', 0 };
        ty = newstruct(op, tag);
        ty->u.sym->src = pos;
        ty->u.sym->defined = 1;
        t = gettok();
        if (istypename(t, tsym))
            fields(ty);
        else
            error("invalid %k field declarations\n", op);
        test('}', stop);
    }
    else if (*tag && (p = lookup(tag, types)) != NULL
    && p->type->op == op) {
        ty = p->type;
        if (t == ';' && p->scope < level)
            ty = newstruct(op, tag);
    }
    else {
        if (*tag == 0)
            error("missing %k tag\n", op);
        ty = newstruct(op, tag);
    }
    if (*tag && xref)
        use(ty->u.sym, pos);
    return ty;
}
static void fields(Type ty) {
    { int n = 0;
      while (istypename(t, tsym)) {
          static char stop[] = { IF, CHAR, '}', 0 };
          Type ty1 = specifier(NULL);
          for (;;) {
              Field p;
              char *id = NULL;
              Type fty = dclr(ty1, &id, NULL, 0);
            p = newfield(id, ty, fty);
            if (Aflag >= 1 && !hasproto(p->type))
                warning("missing prototype\n");
            if (t == ':') {
                if (unqual(p->type) != inttype
                &&  unqual(p->type) != unsignedtype) {
                    error("`%t' is an illegal bit-field type\n",
                        p->type);
                    p->type = inttype;
                }
                t = gettok();
                p->bitsize = intexpr(0, 0);
                if (p->bitsize > 8*inttype->size || p->bitsize < 0) {
                    error("`%d' is an illegal bit-field size\n",
                        p->bitsize);
                    p->bitsize = 8*inttype->size;
                } else if (p->bitsize == 0 && id) {
                    warning("extraneous 0-width bit field `%t %s' ignored\n", p->type, id);

                    p->name = stringd(genlabel(1));
                }
                p->lsb = 1;
            }
            else {
                if (id == NULL)
                    error("field name missing\n");
                else if (isfunc(p->type))
                    error("`%t' is an illegal field type\n", p->type);
                else if (p->type->size == 0)
                    error("undefined size for field `%t %s'\n",
                        p->type, id);
            }
            if (isconst(p->type))
                ty->u.sym->u.s.cfields = 1;
            if (isvolatile(p->type))
                ty->u.sym->u.s.vfields = 1;
              n++;
              if (Aflag >= 2 && n == 128)
                  warning("more than 127 fields in `%t'\n", ty);
              if (t != ',')
                  break;
              t = gettok();
          }
          test(';', stop);
      } }
    { int bits = 0, off = 0, overflow = 0;
      Field p, *q = &ty->u.sym->u.s.flist;
      ty->align = IR->structmetric.align;
      for (p = *q; p; p = p->link) {
          int a = p->type->align ? p->type->align : 1;
        if (p->lsb)
            a = unsignedtype->align;
        if (ty->op == UNION)
            off = bits = 0;
        else if (p->bitsize == 0 || bits == 0
        || bits - 1 + p->bitsize > 8*unsignedtype->size) {
            off = add(off, bits2bytes(bits-1));
            bits = 0;
            chkoverflow(off, a - 1);
            off = roundup(off, a);
        }
        if (a > ty->align)
            ty->align = a;
        p->offset = off;

        if (p->lsb) {
            if (bits == 0)
                bits = 1;
            if (IR->little_endian)
                p->lsb = bits;
            else
                p->lsb = 8*unsignedtype->size - bits + 1
                    - p->bitsize + 1;
            bits += p->bitsize;
        } else
            off = add(off, p->type->size);
        if (off + bits2bytes(bits-1) > ty->size)
            ty->size = off + bits2bytes(bits-1);
          if (p->name == NULL
          || !('1' <= *p->name && *p->name <= '9')) {
              *q = p;
              q = &p->link;
          }
      }
      *q = NULL;
      chkoverflow(ty->size, ty->align - 1);
      ty->size = roundup(ty->size, ty->align);
      if (overflow) {
          error("size of `%t' exceeds %d bytes\n", ty, inttype->u.sym->u.limits.max.i);
          ty->size = inttype->u.sym->u.limits.max.i&(~(ty->align - 1));
      } }
}
static void funcdefn(int sclass, char *id, Type ty, Symbol params[], Coordinate pt) {
    int i, n;
    Symbol *callee, *caller, p;
    Type rty = freturn(ty);

    if (isstruct(rty) && rty->size == 0)
        error("illegal use of incomplete type `%t'\n", rty);
    for (n = 0; params[n]; n++)
        ;
    if (n > 0 && params[n-1]->name == NULL)
        params[--n] = NULL;
    if (Aflag >= 2 && n > 31)
        warning("more than 31 parameters in function `%s'\n", id);
    if (ty->u.f.oldstyle) {
        if (Aflag >= 1)
            warning("old-style function definition for `%s'\n", id);
        caller = params;
        callee = newarray(n + 1, sizeof *callee, FUNC);
        memcpy(callee, caller, (n+1)*sizeof *callee);
        enterscope();
        assert(level == PARAM);
        while (kind[t] == STATIC || istypename(t, tsym))
            decl(dclparam);
        foreach(identifiers, PARAM, oldparam, callee);

        for (i = 0; (p = callee[i]) != NULL; i++) {
            if (!p->defined)
                callee[i] = dclparam(0, p->name, inttype, &p->src);
            *caller[i] = *p;
            caller[i]->sclass = AUTO;
            caller[i]->type = promote(p->type);
        }
        p = lookup(id, identifiers);
        if (p && p->scope == GLOBAL && isfunc(p->type)
        && p->type->u.f.proto) {
            Type *proto = p->type->u.f.proto;
            for (i = 0; caller[i] && proto[i]; i++) {
                Type ty = unqual(proto[i]);
                if (eqtype(isenum(ty) ? ty->type : ty,
                    unqual(caller[i]->type), 1) == 0)
                    break;
                else if (isenum(ty) && !isenum(unqual(caller[i]->type)))
                    warning("compatibility of `%t' and `%t' is compiler dependent\n",
                        proto[i], caller[i]->type);
            }
            if (proto[i] || caller[i])
                error("conflicting argument declarations for function `%s'\n", id);

        }
        else {
            Type *proto = newarray(n + 1, sizeof *proto, PERM);
            if (Aflag >= 1)
                warning("missing prototype for `%s'\n", id);
            for (i = 0; i < n; i++)
                proto[i] = caller[i]->type;
            proto[i] = NULL;
            ty = func(rty, proto, 1);
        }
    } else {
        callee = params;
        caller = newarray(n + 1, sizeof *caller, FUNC);
        for (i = 0; (p = callee[i]) != NULL && p->name; i++) {
            NEW(caller[i], FUNC);
            *caller[i] = *p;
            if (isint(p->type))
                caller[i]->type = promote(p->type);
            caller[i]->sclass = AUTO;
            if ('1' <= *p->name && *p->name <= '9')
                error("missing name for parameter %d to function `%s'\n", i + 1, id);

        }
        caller[i] = NULL;
    }
    for (i = 0; (p = callee[i]) != NULL; i++)
        if (p->type->size == 0) {
            error("undefined size for parameter `%t %s'\n",
                p->type, p->name);
            caller[i]->type = p->type = inttype;
        }
    if (Aflag >= 2 && sclass != STATIC && strcmp(id, "main") == 0) {
        if (ty->u.f.oldstyle)
            warning("`%t %s()' is a non-ANSI definition\n", rty, id);
        else if (!(rty == inttype
            && (n == 0 && callee[0] == NULL
            ||  n == 2 && callee[0]->type == inttype
            && isptr(callee[1]->type) && callee[1]->type->type == charptype
            && !variadic(ty))))
            warning("`%s' is a non-ANSI definition\n", typestring(ty, id));
    }
    p = lookup(id, identifiers);
    if (p && isfunc(p->type) && p->defined)
        error("redefinition of `%s' previously defined at %w\n",
            p->name, &p->src);
    cfunc = dclglobal(sclass, id, ty, &pt);
    cfunc->u.f.label = genlabel(1);
    cfunc->u.f.callee = callee;
    cfunc->u.f.pt = src;
    cfunc->defined = 1;
    if (xref)
        use(cfunc, cfunc->src);
    if (Pflag)
        printproto(cfunc, cfunc->u.f.callee);
    if (ncalled >= 0)
        ncalled = findfunc(cfunc->name, pt.file);
    labels   = table(NULL, LABELS);
    stmtlabs = table(NULL, LABELS);
    refinc = 1.0;
    regcount = 0;
    codelist = &codehead;
    codelist->next = NULL;
    if (!IR->wants_callb && isstruct(rty))
        retv = genident(AUTO, ptr(unqual(rty)), PARAM);
    compound(0, NULL, 0);

    definelab(cfunc->u.f.label);
    if (events.exit)
        apply(events.exit, cfunc, NULL);
    walk(NULL, 0, 0);
    exitscope();
    assert(level == PARAM);
    foreach(identifiers, level, checkref, NULL);
    if (!IR->wants_callb && isstruct(rty)) {
        Symbol *a;
        a = newarray(n + 2, sizeof *a, FUNC);
        a[0] = retv;
        memcpy(&a[1], callee, (n+1)*sizeof *callee);
        callee = a;
        a = newarray(n + 2, sizeof *a, FUNC);
        NEW(a[0], FUNC);
        *a[0] = *retv;
        memcpy(&a[1], caller, (n+1)*sizeof *callee);
        caller = a;
    }
    if (!IR->wants_argb)
        for (i = 0; caller[i]; i++)
            if (isstruct(caller[i]->type)) {
                caller[i]->type = ptr(caller[i]->type);
                callee[i]->type = ptr(callee[i]->type);
                caller[i]->structarg = callee[i]->structarg = 1;
            }
    if (glevel > 1)    for (i = 0; callee[i]; i++) callee[i]->sclass = AUTO;
    if (cfunc->sclass != STATIC)
        (*IR->export)(cfunc);
    if (glevel && IR->stabsym) {
        swtoseg(CODE); (*IR->stabsym)(cfunc); }
    swtoseg(CODE);
    (*IR->function)(cfunc, caller, callee, cfunc->u.f.ncalls);
    if (glevel && IR->stabfend)
        (*IR->stabfend)(cfunc, lineno);
    foreach(stmtlabs, LABELS, checklab, NULL);
    exitscope();
    expect('}');
    labels = stmtlabs = NULL;
    retv  = NULL;
    cfunc = NULL;
}
static void oldparam(Symbol p, void *cl) {
    int i;
    Symbol *callee = cl;

    for (i = 0; callee[i]; i++)
        if (p->name == callee[i]->name) {
            callee[i] = p;
            return;
        }
    error("declared parameter `%s' is missing\n", p->name);
}
void compound(int loop, struct swtch *swp, int lev) {
    Code cp;
    int nregs;

    walk(NULL, 0, 0);
    cp = code(Blockbeg);
    enterscope();
    assert(level >= LOCAL);
    if (level == LOCAL && events.entry)
        apply(events.entry, cfunc, NULL);
    definept(NULL);
    expect('{');
    autos = registers = NULL;
    if (level == LOCAL && IR->wants_callb
    && isstruct(freturn(cfunc->type))) {
        retv = genident(AUTO, ptr(unqual(freturn(cfunc->type))), level);
        retv->defined = 1;
        retv->ref = 1;
        registers = append(retv, registers);
    }
    while (kind[t] == CHAR || kind[t] == STATIC
    || istypename(t, tsym) && getchr() != ':')
        decl(dcllocal);
    {
        int i;
        Symbol *a = ltov(&autos, STMT);
        nregs = length(registers);
        for (i = 0; a[i]; i++)
            registers = append(a[i], registers);
        cp->u.block.locals = ltov(&registers, FUNC);
    }
    if (events.blockentry)
        apply(events.blockentry, cp->u.block.locals, NULL);
    while (kind[t] == IF || kind[t] == ID)
        statement(loop, swp, lev);
    walk(NULL, 0, 0);
    foreach(identifiers, level, checkref, NULL);
    {
        int i = nregs, j;
        Symbol p;
        for ( ; (p = cp->u.block.locals[i]) != NULL; i++) {
            for (j = i; j > nregs
                && cp->u.block.locals[j-1]->ref < p->ref; j--)
                cp->u.block.locals[j] = cp->u.block.locals[j-1];
            cp->u.block.locals[j] = p;
        }
    }
    if (level == LOCAL) {
        Code cp;
        for (cp = codelist; cp->kind < Label; cp = cp->prev)
            ;
        if (cp->kind != Jump) {
            if (freturn(cfunc->type) != voidtype) {
                warning("missing return value\n");
                retcode(cnsttree(inttype, 0L));
            } else
                retcode(NULL);
        }
    }
    if (events.blockexit)
        apply(events.blockexit, cp->u.block.locals, NULL);
    cp->u.block.level = level;
    cp->u.block.identifiers = identifiers;
    cp->u.block.types = types;
    code(Blockend)->u.begin = cp;
    if (reachable(Gen))
        definept(NULL);
    if (level > LOCAL) {
        exitscope();
        expect('}');
    }
}
static void checkref(Symbol p, void *cl) {
    if (p->scope >= PARAM
    && (isvolatile(p->type) || isfunc(p->type)))
        p->addressed = 1;
    if (Aflag >= 2 && p->defined && p->ref == 0) {
        if (p->sclass == STATIC)
            warning("static `%t %s' is not referenced\n",
                p->type, p->name);
        else if (p->scope == PARAM)
            warning("parameter `%t %s' is not referenced\n",
                p->type, p->name);
        else if (p->scope >= LOCAL && p->sclass != EXTERN)
            warning("local `%t %s' is not referenced\n",
                p->type, p->name);
    }
    if (p->sclass == AUTO
    && (p->scope  == PARAM && regcount == 0
     || p->scope  >= LOCAL)
    && !p->addressed && isscalar(p->type) && p->ref >= 3.0)
        p->sclass = REGISTER;
    if (level == GLOBAL && p->sclass == STATIC && !p->defined
    && isfunc(p->type) && p->ref)
        error("undefined static `%t %s'\n", p->type, p->name);
    assert(!(level == GLOBAL && p->sclass == STATIC && !p->defined && !isfunc(p->type)));
}
static Symbol dcllocal(int sclass, char *id, Type ty, Coordinate *pos) {
    Symbol p, q;

    if (sclass == 0)
        sclass = isfunc(ty) ? EXTERN : AUTO;
    else if (isfunc(ty) && sclass != EXTERN) {
        error("invalid storage class `%k' for `%t %s'\n",
            sclass, ty, id);
        sclass = EXTERN;
    } else if (sclass == REGISTER
    && (isvolatile(ty) || isstruct(ty) || isarray(ty))) {
        warning("register declaration ignored for `%t %s'\n",
            ty, id);
        sclass = AUTO;
    }
    q = lookup(id, identifiers);
    if (q && q->scope >= level
    ||  q && q->scope == PARAM && level == LOCAL)
        if (sclass == EXTERN && q->sclass == EXTERN
        && eqtype(q->type, ty, 1))
            ty = compose(ty, q->type);
        else
            error("redeclaration of `%s' previously declared at %w\n", q->name, &q->src);

    assert(level >= LOCAL);
    p = install(id, &identifiers, level, sclass == STATIC || sclass == EXTERN ? PERM : FUNC);
    p->type = ty;
    p->sclass = sclass;
    p->src = *pos;
    switch (sclass) {
    case EXTERN:   q = lookup(id, globals);
               if (q == NULL || q->sclass == TYPEDEF || q->sclass == ENUM) {
                   q = lookup(id, externals);
                   if (q == NULL) {
                       q = install(p->name, &externals, GLOBAL, PERM);
                       q->type = p->type;
                       q->sclass = EXTERN;
                       q->src = src;
                       (*IR->defsymbol)(q);
                   }
               }
               if (!eqtype(p->type, q->type, 1))
                   warning("declaration of `%s' does not match previous declaration at %w\n", q->name, &q->src);

               p->u.alias = q; break;
    case STATIC:   (*IR->defsymbol)(p);
               initglobal(p, 0);
               if (!p->defined)
                   if (p->type->size > 0) {
                       defglobal(p, BSS);
                       (*IR->space)(p->type->size);
                   } else
                       error("undefined size for `%t %s'\n",
                           p->type, p->name);
               p->defined = 1; break;
    case REGISTER: registers = append(p, registers);
               regcount++;
               p->defined = 1;
 break;
    case AUTO:     autos = append(p, autos);
               p->defined = 1;
               if (isarray(ty))
                   p->addressed = 1; break;
    default: assert(0);
    }
    if (t == '=') {
        Tree e;
        if (sclass == EXTERN)
            error("illegal initialization of `extern %s'\n", id);
        t = gettok();
        definept(NULL);
        if (isscalar(p->type)
        ||  isstruct(p->type) && t != '{') {
            if (t == '{') {
                t = gettok();
                e = expr1(0);
                expect('}');
            } else
                e = expr1(0);
        } else {
            Symbol t1;
            Type ty = p->type, ty1 = ty;
            while (isarray(ty1))
                ty1 = ty1->type;
            if (!isconst(ty) && (!isarray(ty) || !isconst(ty1)))
                ty = qual(CONST, ty);
            t1 = genident(STATIC, ty, GLOBAL);
            initglobal(t1, 1);
            if (isarray(p->type) && p->type->size == 0
            && t1->type->size > 0)
                p->type = array(p->type->type,
                    t1->type->size/t1->type->type->size, 0);
            e = idtree(t1);
        }
        walk(root(asgn(p, e)), 0, 0);
        p->ref = 1;
    }
    if (!isfunc(p->type) && p->defined && p->type->size <= 0)
        error("undefined size for `%t %s'\n", p->type, id);
    return p;
}
void finalize(void) {
    foreach(externals,   GLOBAL,    doextern, NULL);
    foreach(identifiers, GLOBAL,    doglobal, NULL);
    foreach(identifiers, GLOBAL,    checkref, NULL);
    foreach(constants,   CONSTANTS, doconst,  NULL);
}
static void doextern(Symbol p, void *cl) {
    (*IR->import)(p);
}
static void doglobal(Symbol p, void *cl) {
    if (!p->defined && (p->sclass == EXTERN
    || isfunc(p->type) && p->sclass == AUTO))
        (*IR->import)(p);
    else if (!p->defined && !isfunc(p->type)
    && (p->sclass == AUTO || p->sclass == STATIC)) {
        if (isarray(p->type)
        && p->type->size == 0 && p->type->type->size > 0)
            p->type = array(p->type->type, 1, 0);
        if (p->type->size > 0) {
            defglobal(p, BSS);
            (*IR->space)(p->type->size);
            if (glevel > 0 && IR->stabsym)
                (*IR->stabsym)(p);
        } else
            error("undefined size for `%t %s'\n",
                p->type, p->name);
        p->defined = 1;
    }
    if (Pflag
    && !isfunc(p->type)
    && !p->generated && p->sclass != EXTERN)
        printdecl(p, p->type);
}
void doconst(Symbol p, void *cl) {
    if (p->u.c.loc) {
        assert(p->u.c.loc->u.seg == 0); 
        defglobal(p->u.c.loc, LIT);
        if (isarray(p->type) && p->type->type == widechar) {
            unsigned int *s = p->u.c.v.p;
            int n = p->type->size/widechar->size;
            while (n-- > 0) {
                Value v;
                v.u = *s++;
                (*IR->defconst)(widechar->op, widechar->size, v);
            }
        } else if (isarray(p->type))
            (*IR->defstring)(p->type->size, p->u.c.v.p);
        else
            (*IR->defconst)(p->type->op, p->type->size, p->u.c.v);
        p->u.c.loc = NULL;
    }
}
void checklab(Symbol p, void *cl) {
    if (!p->defined)
        error("undefined label `%s'\n", p->name);
    p->defined = 1;
}

Type enumdcl(void) {
    char *tag;
    Type ty;
    Symbol p;
    Coordinate pos;

    t = gettok();
    pos = src;
    if (t == ID) {
        tag = token;
        t = gettok();
    } else
        tag = "";
    if (t == '{') {
        static char follow[] = { IF, 0 };
        int n = 0;
        long k = -1;
        List idlist = 0;
        ty = newstruct(ENUM, tag);
        t = gettok();
        if (t != ID)
            error("expecting an enumerator identifier\n");
        while (t == ID) {
            char *id = token;
            Coordinate s;
            if (tsym && tsym->scope == level)
                error("redeclaration of `%s' previously declared at %w\n",
                    token, &tsym->src);
            s = src;
            t = gettok();
            if (t == '=') {
                t = gettok();
                k = intexpr(0, 0);
            } else {
                if (k == inttype->u.sym->u.limits.max.i)
                    error("overflow in value for enumeration constant `%s'\n", id);
                k++;
            }
            p = install(id, &identifiers, level,  level < LOCAL ? PERM : FUNC);
            p->src = s;
            p->type = ty;
            p->sclass = ENUM;
            p->u.value = k;
            idlist = append(p, idlist);
            n++;
            if (Aflag >= 2 && n == 128)
                warning("more than 127 enumeration constants in `%t'\n", ty);
            if (t != ',')
                break;
            t = gettok();
            if (Aflag >= 2 && t == '}')
                warning("non-ANSI trailing comma in enumerator list\n");
        }
        test('}', follow);
        ty->type = inttype;
        ty->size = ty->type->size;
        ty->align = ty->type->align;
        ty->u.sym->u.idlist = ltov(&idlist, PERM);
        ty->u.sym->defined = 1;
    } else if ((p = lookup(tag, types)) != NULL && p->type->op == ENUM) {
        ty = p->type;
        if (t == ';')
            error("empty declaration\n");
    } else {
        error("unknown enumeration `%s'\n",  tag);
        ty = newstruct(ENUM, tag);
        ty->type = inttype;
    }
    if (*tag && xref)
        use(p, pos);
    return ty;
}

Type typename(void) {
    Type ty = specifier(NULL);

    if (t == '*' || t == '(' || t == '[') {
        ty = dclr(ty, NULL, NULL, 1);
        if (Aflag >= 1 && !hasproto(ty))
            warning("missing prototype\n");
    }
    return ty;
}