#include "c.h"

static char rcsid[] = "$Id: decl.nw,v 2.17 1997/05/20 21:49:29 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:
    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  && 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)
    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) {
    p = install(id, &globals, GLOBAL, PERM);
    p->sclass = sclass;
    if (p->sclass != STATIC) {
      static int nglobals;
      nglobals++;
      if (Aflag >= 2 && nglobals == 512)
        warning("more than 511 external identifiers\n");
    }
    (*IR->defsymbol)(p);
  } else if (p->sclass == EXTERN)
    p->sclass = sclass;
  p->type = ty;
  p->src = *pos;
  {
    Symbol q = lookup(p->name, externals);
    if (q && (p->sclass == STATIC
        || !eqtype(p->type, q->type, 1)))
      warning("declaration of `%s' does not match previous declaration at %w\n", p->name, &q->src);

  }
  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 == ptr(chartype)
      && !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(rty), PARAM);
  compound(0, NULL, 0);

  {
    Code cp;
    for (cp = codelist; cp->kind < Label; cp = cp->prev)
      ;
    if (cp->kind != Jump) {
      if (rty != voidtype)
        warning("missing return value\n");
      retcode(NULL);
    }
  }
  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(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 (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 (p->scope >= LOCAL && p->sclass == EXTERN) {
    Symbol q = lookup(p->name, externals);
    assert(q);
    q->ref += p->ref;
  }
  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, FUNC);
  p->type = ty;
  p->sclass = sclass;
  p->src = *pos;
  switch (sclass) {
  case EXTERN:   if (q && q->scope == GLOBAL && q->sclass == STATIC) {
             p->sclass = STATIC;
             p->scope = GLOBAL;
             (*IR->defsymbol)(p);
             p->sclass = EXTERN;
             p->scope = level;
           } else
             (*IR->defsymbol)(p);
           {
             Symbol r = lookup(id, externals);
             if (r == NULL) {
               r = install(p->name, &externals, GLOBAL, PERM);
               r->src = p->src;
               r->type = p->type;
               r->sclass = p->sclass;
               q = lookup(id, globals);
               if (q && q->sclass != TYPEDEF && q->sclass != ENUM)
                 r = q;
             }
             if (r && !eqtype(r->type, p->type, 1))
               warning("declaration of `%s' does not match previous declaration at %w\n", r->name, &r->src);

           } 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; 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) {
  Symbol q = lookup(p->name, identifiers);

  if (q)
    q->ref += p->ref;
  else {
    (*IR->defsymbol)(p);
    (*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);
    } 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))
      (*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;
}

