Put some validation scripts in the closet.

[smatch.git] / symbol.c

/*
 * Symbol lookup and handling.
 *
 * Copyright (C) 2003 Transmeta Corp.
 *               2003-2004 Linus Torvalds
 *
 *  Licensed under the Open Software License version 1.1
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "lib.h"
#include "allocate.h"
#include "token.h"
#include "parse.h"
#include "symbol.h"
#include "scope.h"
#include "expression.h"

#include "target.h"

/*
 * Secondary symbol list for stuff that needs to be output because it
 * was used. 
 */
struct symbol_list *translation_unit_used_list = NULL;

/*
 * If the symbol is an inline symbol, add it to the list of symbols to parse
 */
void access_symbol(struct symbol *sym)
{
        if (sym->ctype.modifiers & MOD_INLINE) {
                if (!(sym->ctype.modifiers & MOD_ACCESSED)) {
                        add_symbol(&translation_unit_used_list, sym);
                        sym->ctype.modifiers |= MOD_ACCESSED;
                }
        }
}

struct symbol *lookup_symbol(struct ident *ident, enum namespace ns)
{
        struct symbol *sym;

        for (sym = ident->symbols; sym; sym = sym->next_id) {
                if (sym->namespace & ns) {
                        sym->used = 1;
                        return sym;
                }
        }
        return sym;
}

struct context *alloc_context(void)
{
        return __alloc_context(0);
}

struct symbol *alloc_symbol(struct position pos, int type)
{
        struct symbol *sym = __alloc_symbol(0);
        sym->type = type;
        sym->pos = pos;
        sym->endpos.type = 0;
        return sym;
}

struct struct_union_info {
        unsigned long max_align;
        unsigned long bit_size;
        int align_size;
};

/*
 * Unions are fairly easy to lay out ;)
 */
static void lay_out_union(struct symbol *sym, struct struct_union_info *info)
{
        examine_symbol_type(sym);

        // Unnamed bitfields do not affect alignment.
        if (sym->ident || !is_bitfield_type(sym)) {
                if (sym->ctype.alignment > info->max_align)
                        info->max_align = sym->ctype.alignment;
        }

        if (sym->bit_size > info->bit_size)
                info->bit_size = sym->bit_size;

        sym->offset = 0;
}

static int bitfield_base_size(struct symbol *sym)
{
        if (sym->type == SYM_NODE)
                sym = sym->ctype.base_type;
        if (sym->type == SYM_BITFIELD)
                sym = sym->ctype.base_type;
        return sym->bit_size;
}

/*
 * Structures are a bit more interesting to lay out
 */
static void lay_out_struct(struct symbol *sym, struct struct_union_info *info)
{
        unsigned long bit_size, align_bit_mask;
        int base_size;

        examine_symbol_type(sym);

        // Unnamed bitfields do not affect alignment.
        if (sym->ident || !is_bitfield_type(sym)) {
                if (sym->ctype.alignment > info->max_align)
                        info->max_align = sym->ctype.alignment;
        }

        bit_size = info->bit_size;
        base_size = sym->bit_size; 

        /*
         * Unsized arrays cause us to not align the resulting
         * structure size
         */
        if (base_size < 0) {
                info->align_size = 0;
                base_size = 0;
        }

        align_bit_mask = (sym->ctype.alignment << 3) - 1;

        /*
         * Bitfields have some very special rules..
         */
        if (is_bitfield_type (sym)) {
                unsigned long bit_offset = bit_size & align_bit_mask;
                int room = bitfield_base_size(sym) - bit_offset;
                // Zero-width fields just fill up the unit.
                int width = base_size ? : (bit_offset ? room : 0);

                if (width > room) {
                        bit_size = (bit_size + align_bit_mask) & ~align_bit_mask;
                        bit_offset = 0;
                }
                sym->offset = (bit_size - bit_offset) >> 3;
                sym->bit_offset = bit_offset;
                sym->ctype.base_type->bit_offset = bit_offset;
                info->bit_size = bit_size + width;
                // warning (sym->pos, "bitfield: offset=%d:%d  size=:%d", sym->offset, sym->bit_offset, width);

                return;
        }

        /*
         * Otherwise, just align it right and add it up..
         */
        bit_size = (bit_size + align_bit_mask) & ~align_bit_mask;
        sym->offset = bit_size >> 3;

        info->bit_size = bit_size + base_size;
        // warning (sym->pos, "regular: offset=%d", sym->offset);
}

static struct symbol * examine_struct_union_type(struct symbol *sym, int advance)
{
        struct struct_union_info info = {
                .max_align = 1,
                .bit_size = 0,
                .align_size = 1
        };
        unsigned long bit_size, bit_align;
        void (*fn)(struct symbol *, struct struct_union_info *);
        struct symbol *member;

        fn = advance ? lay_out_struct : lay_out_union;
        FOR_EACH_PTR(sym->symbol_list, member) {
                fn(member, &info);
        } END_FOR_EACH_PTR(member);

        if (!sym->ctype.alignment)
                sym->ctype.alignment = info.max_align;
        bit_size = info.bit_size;
        if (info.align_size) {
                bit_align = (sym->ctype.alignment << 3)-1;
                bit_size = (bit_size + bit_align) & ~bit_align;
        }
        sym->bit_size = bit_size;
        return sym;
}

static struct symbol *examine_base_type(struct symbol *sym)
{
        struct symbol *base_type;

        /* Check the base type */
        base_type = examine_symbol_type(sym->ctype.base_type);
        if (!base_type || base_type->type == SYM_PTR)
                return base_type;
        sym->ctype.as |= base_type->ctype.as;
        sym->ctype.modifiers |= base_type->ctype.modifiers & MOD_PTRINHERIT;
        concat_ptr_list((struct ptr_list *)base_type->ctype.contexts,
                        (struct ptr_list **)&sym->ctype.contexts);
        if (base_type->type == SYM_NODE) {
                base_type = base_type->ctype.base_type;
                sym->ctype.base_type = base_type;
        }
        return base_type;
}

static struct symbol * examine_array_type(struct symbol *sym)
{
        struct symbol *base_type = examine_base_type(sym);
        unsigned long bit_size, alignment;

        if (!base_type)
                return sym;
        bit_size = base_type->bit_size * get_expression_value(sym->array_size);
        if (!sym->array_size || sym->array_size->type != EXPR_VALUE)
                bit_size = -1;
        alignment = base_type->ctype.alignment;
        if (!sym->ctype.alignment)
                sym->ctype.alignment = alignment;
        sym->bit_size = bit_size;
        return sym;
}

static struct symbol *examine_bitfield_type(struct symbol *sym)
{
        struct symbol *base_type = examine_base_type(sym);
        unsigned long bit_size, alignment, modifiers;

        if (!base_type)
                return sym;
        bit_size = base_type->bit_size;
        if (sym->bit_size > bit_size)
                warning(sym->pos, "impossible field-width, %d, for this type",  sym->bit_size);

        alignment = base_type->ctype.alignment;
        if (!sym->ctype.alignment)
                sym->ctype.alignment = alignment;
        modifiers = base_type->ctype.modifiers;

        /* Bitfields are unsigned, unless the base type was explicitly signed */
        if (!(modifiers & MOD_EXPLICITLY_SIGNED))
                modifiers = (modifiers & ~MOD_SIGNED) | MOD_UNSIGNED;
        sym->ctype.modifiers |= modifiers & MOD_SIGNEDNESS;
        return sym;
}

/*
 * "typeof" will have to merge the types together
 */
void merge_type(struct symbol *sym, struct symbol *base_type)
{
        sym->ctype.as |= base_type->ctype.as;
        sym->ctype.modifiers |= (base_type->ctype.modifiers & ~MOD_STORAGE);
        concat_ptr_list((struct ptr_list *)base_type->ctype.contexts,
                        (struct ptr_list **)&sym->ctype.contexts);
        sym->ctype.base_type = base_type->ctype.base_type;
        if (sym->ctype.base_type->type == SYM_NODE)
                merge_type(sym, sym->ctype.base_type);
}

static int count_array_initializer(struct symbol *t, struct expression *expr)
{
        int nr = 0;
        int is_char = 0;

        /*
         * Arrays of character types are special; they can be initialized by
         * string literal _or_ by string literal in braces.  The latter means
         * that with T x[] = {<string literal>} number of elements in x depends
         * on T - if it's a character type, we get the length of string literal
         * (including NUL), otherwise we have one element here.
         */
        if (t->ctype.base_type == &int_type && t->ctype.modifiers & MOD_CHAR)
                is_char = 1;

        switch (expr->type) {
        case EXPR_INITIALIZER: {
                struct expression *entry;
                int count = 0;
                int str_len = 0;
                FOR_EACH_PTR(expr->expr_list, entry) {
                        count++;
                        switch (entry->type) {
                        case EXPR_INDEX:
                                if (entry->idx_to >= nr)
                                        nr = entry->idx_to+1;
                                break;
                        case EXPR_STRING:
                                if (is_char)
                                        str_len = entry->string->length;
                        default:
                                nr++;
                        }
                } END_FOR_EACH_PTR(entry);
                if (count == 1 && str_len)
                        nr = str_len;
                break;
        }
        case EXPR_STRING:
                if (is_char)
                        nr = expr->string->length;
        default:
                break;
        }
        return nr;
}

static struct symbol * examine_node_type(struct symbol *sym)
{
        struct symbol *base_type = examine_base_type(sym);
        int bit_size;
        unsigned long alignment, modifiers;

        /* SYM_NODE - figure out what the type of the node was.. */
        modifiers = sym->ctype.modifiers;

        bit_size = 0;
        alignment = 0;
        if (!base_type)
                return sym;

        bit_size = base_type->bit_size;
        alignment = base_type->ctype.alignment;

        /* Pick up signedness information into the node */
        sym->ctype.modifiers |= (MOD_SIGNEDNESS & base_type->ctype.modifiers);

        if (!sym->ctype.alignment)
                sym->ctype.alignment = alignment;

        /* Unsized array? The size might come from the initializer.. */
        if (bit_size < 0 && base_type->type == SYM_ARRAY && sym->initializer) {
                struct symbol *node_type = base_type->ctype.base_type;
                int count = count_array_initializer(node_type, sym->initializer);

                if (node_type && node_type->bit_size >= 0)
                        bit_size = node_type->bit_size * count;
        }
        
        sym->bit_size = bit_size;
        return sym;
}

static struct symbol *examine_enum_type(struct symbol *sym)
{
        struct symbol *base_type = examine_base_type(sym);

        sym->ctype.modifiers |= (base_type->ctype.modifiers & MOD_SIGNEDNESS);
        sym->bit_size = bits_in_enum;
        if (base_type->bit_size > sym->bit_size)
                sym->bit_size = base_type->bit_size;
        sym->ctype.alignment = enum_alignment;
        if (base_type->ctype.alignment > sym->ctype.alignment)
                sym->ctype.alignment = base_type->ctype.alignment;
        return sym;
}

static struct symbol *examine_pointer_type(struct symbol *sym)
{
        /*
         * We need to set the pointer size first, and
         * examine the thing we point to only afterwards.
         * That's because this pointer type may end up
         * being needed for the base type size evaluation.
         */
        if (!sym->bit_size)
                sym->bit_size = bits_in_pointer;
        if (!sym->ctype.alignment)
                sym->ctype.alignment = pointer_alignment;
        return sym;
}

/*
 * Fill in type size and alignment information for
 * regular SYM_TYPE things.
 */
struct symbol *examine_symbol_type(struct symbol * sym)
{
        if (!sym)
                return sym;

        /* Already done? */
        if (sym->examined)
                return sym;
        sym->examined = 1;

        switch (sym->type) {
        case SYM_FN:
        case SYM_NODE:
                return examine_node_type(sym);
        case SYM_ARRAY:
                return examine_array_type(sym);
        case SYM_STRUCT:
                return examine_struct_union_type(sym, 1);
        case SYM_UNION:
                return examine_struct_union_type(sym, 0);
        case SYM_PTR:
                return examine_pointer_type(sym);
        case SYM_ENUM:
                return examine_enum_type(sym);
        case SYM_BITFIELD:
                return examine_bitfield_type(sym);
        case SYM_BASETYPE:
                /* Size and alignment had better already be set up */
                return sym;
        case SYM_TYPEOF: {
                struct symbol *base = evaluate_expression(sym->initializer);
                if (base) {
                        if (is_bitfield_type(base))
                                warning(base->pos, "typeof applied to bitfield type");
                        if (base->type == SYM_NODE)
                                base = base->ctype.base_type;
                        sym->type = SYM_NODE;
                        sym->ctype.modifiers = 0;
                        sym->ctype.base_type = base;
                        return examine_node_type(sym);
                }
                break;
        }
        case SYM_PREPROCESSOR:
                sparse_error(sym->pos, "ctype on preprocessor command? (%s)", show_ident(sym->ident));
                return NULL;
        case SYM_UNINITIALIZED:
                sparse_error(sym->pos, "ctype on uninitialized symbol %p", sym);
                return NULL;
        case SYM_RESTRICT:
                examine_base_type(sym);
                return sym;
        case SYM_FOULED:
                examine_base_type(sym);
                return sym;
        default:
                sparse_error(sym->pos, "Examining unknown symbol type %d", sym->type);
                break;
        }
        return sym;
}

const char* get_type_name(enum type type)
{
        const char *type_lookup[] = {
        [SYM_UNINITIALIZED] = "uninitialized",
        [SYM_PREPROCESSOR] = "preprocessor",
        [SYM_BASETYPE] = "basetype",
        [SYM_NODE] = "node",
        [SYM_PTR] = "pointer",
        [SYM_FN] = "function",
        [SYM_ARRAY] = "array",
        [SYM_STRUCT] = "struct",
        [SYM_UNION] = "union",
        [SYM_ENUM] = "enum",
        [SYM_TYPEDEF] = "typedef",
        [SYM_TYPEOF] = "typeof",
        [SYM_MEMBER] = "member",
        [SYM_BITFIELD] = "bitfield",
        [SYM_LABEL] = "label",
        [SYM_RESTRICT] = "restrict",
        [SYM_FOULED] = "fouled",
        [SYM_KEYWORD] = "keyword",
        [SYM_BAD] = "bad"};

        if (type <= SYM_BAD)
                return type_lookup[type];
        else
                return NULL;
}

struct symbol *examine_pointer_target(struct symbol *sym)
{
        return examine_base_type(sym);
}

static struct symbol_list *restr, *fouled;

void create_fouled(struct symbol *type)
{
        if (type->bit_size < bits_in_int) {
                struct symbol *new = alloc_symbol(type->pos, type->type);
                *new = *type;
                new->bit_size = bits_in_int;
                new->type = SYM_FOULED;
                new->ctype.base_type = type;
                add_symbol(&restr, type);
                add_symbol(&fouled, new);
        }
}

struct symbol *befoul(struct symbol *type)
{
        struct symbol *t1, *t2;
        while (type->type == SYM_NODE)
                type = type->ctype.base_type;
        PREPARE_PTR_LIST(restr, t1);
        PREPARE_PTR_LIST(fouled, t2);
        for (;;) {
                if (t1 == type)
                        return t2;
                if (!t1)
                        break;
                NEXT_PTR_LIST(t1);
                NEXT_PTR_LIST(t2);
        }
        FINISH_PTR_LIST(t2);
        FINISH_PTR_LIST(t1);
        return NULL;
}

void check_declaration(struct symbol *sym)
{
        int warned = 0;
        struct symbol *next = sym;

        while ((next = next->next_id) != NULL) {
                if (next->namespace != sym->namespace)
                        continue;
                if (sym->scope == next->scope) {
                        sym->same_symbol = next;
                        return;
                }
                if (sym->ctype.modifiers & next->ctype.modifiers & MOD_EXTERN) {
                        sym->same_symbol = next;
                        return;
                }

                if (!Wshadow || warned)
                        continue;
                if (get_sym_type(next) == SYM_FN)
                        continue;
                warned = 1;
                warning(sym->pos, "symbol '%s' shadows an earlier one", show_ident(sym->ident));
                info(next->pos, "originally declared here");
        }
}

void bind_symbol(struct symbol *sym, struct ident *ident, enum namespace ns)
{
        struct scope *scope;
        if (sym->bound) {
                sparse_error(sym->pos, "internal error: symbol type already bound");
                return;
        }
        if (ident->reserved && (ns & (NS_TYPEDEF | NS_STRUCT | NS_LABEL | NS_SYMBOL))) {
                sparse_error(sym->pos, "Trying to use reserved word '%s' as identifier", show_ident(ident));
                return;
        }
        sym->namespace = ns;
        sym->next_id = ident->symbols;
        ident->symbols = sym;
        if (sym->ident && sym->ident != ident)
                warning(sym->pos, "Symbol '%s' already bound", show_ident(sym->ident));
        sym->ident = ident;
        sym->bound = 1;

        scope = block_scope;
        if (ns == NS_SYMBOL && toplevel(scope)) {
                unsigned mod = MOD_ADDRESSABLE | MOD_TOPLEVEL;
                scope = global_scope;
                if (sym->ctype.modifiers & MOD_STATIC) {
                        scope = file_scope;
                        mod = MOD_TOPLEVEL;
                }
                sym->ctype.modifiers |= mod;
        }
        if (ns == NS_MACRO)
                scope = file_scope;
        if (ns == NS_LABEL)
                scope = function_scope;
        bind_scope(sym, scope);
}

struct symbol *create_symbol(int stream, const char *name, int type, int namespace)
{
        struct token *token = built_in_token(stream, name);
        struct symbol *sym = alloc_symbol(token->pos, type);

        bind_symbol(sym, token->ident, namespace);
        return sym;
}

static int evaluate_to_integer(struct expression *expr)
{
        expr->ctype = &int_ctype;
        return 1;
}

static int evaluate_expect(struct expression *expr)
{
        /* Should we evaluate it to return the type of the first argument? */
        expr->ctype = &int_ctype;
        return 1;
}

static int arguments_choose(struct expression *expr)
{
        struct expression_list *arglist = expr->args;
        struct expression *arg;
        int i = 0;

        FOR_EACH_PTR (arglist, arg) {
                if (!evaluate_expression(arg))
                        return 0;
                i++;
        } END_FOR_EACH_PTR(arg);
        if (i < 3) {
                sparse_error(expr->pos,
                             "not enough arguments for __builtin_choose_expr");
                return 0;
        } if (i > 3) {
                sparse_error(expr->pos,
                             "too many arguments for __builtin_choose_expr");
                return 0;
        }
        return 1;
}

static int evaluate_choose(struct expression *expr)
{
        struct expression_list *list = expr->args;
        struct expression *arg, *args[3];
        int n = 0;

        /* there will be exactly 3; we'd already verified that */
        FOR_EACH_PTR(list, arg) {
                args[n++] = arg;
        } END_FOR_EACH_PTR(arg);

        *expr = get_expression_value(args[0]) ? *args[1] : *args[2];

        return 1;
}

static int expand_expect(struct expression *expr, int cost)
{
        struct expression *arg = first_ptr_list((struct ptr_list *) expr->args);

        if (arg)
                *expr = *arg;
        return 0;
}

/*
 * __builtin_warning() has type "int" and always returns 1,
 * so that you can use it in conditionals or whatever
 */
static int expand_warning(struct expression *expr, int cost)
{
        struct expression *arg;
        struct expression_list *arglist = expr->args;

        FOR_EACH_PTR (arglist, arg) {
                /*
                 * Constant strings get printed out as a warning. By the
                 * time we get here, the EXPR_STRING has been fully 
                 * evaluated, so by now it's an anonymous symbol with a
                 * string initializer.
                 *
                 * Just for the heck of it, allow any constant string
                 * symbol.
                 */
                if (arg->type == EXPR_SYMBOL) {
                        struct symbol *sym = arg->symbol;
                        if (sym->initializer && sym->initializer->type == EXPR_STRING) {
                                struct string *string = sym->initializer->string;
                                warning(expr->pos, "%*s", string->length-1, string->data);
                        }
                        continue;
                }

                /*
                 * Any other argument is a conditional. If it's
                 * non-constant, or it is false, we exit and do
                 * not print any warning.
                 */
                if (arg->type != EXPR_VALUE)
                        goto out;
                if (!arg->value)
                        goto out;
        } END_FOR_EACH_PTR(arg);
out:
        expr->type = EXPR_VALUE;
        expr->value = 1;
        expr->taint = 0;
        return 0;
}

/*
 * Type and storage class keywords need to have the symbols
 * created for them, so that the parser can have enough semantic
 * information to do parsing.
 *
 * "double" == "long float", "long double" == "long long float"
 */
static struct sym_init {
        const char *name;
        struct symbol *base_type;
        unsigned int modifiers;
        struct symbol_op *op;
} symbol_init_table[] = {
        /* Storage class */
        { "auto",       NULL,           MOD_AUTO },
        { "register",   NULL,           MOD_REGISTER },
        { "static",     NULL,           MOD_STATIC },
        { "extern",     NULL,           MOD_EXTERN },

        /* Type specifiers */
        { "void",       &void_ctype,    0 },
        { "char",       NULL,           MOD_CHAR },
        { "short",      NULL,           MOD_SHORT },
        { "int",        &int_type,      0 },
        { "long",       NULL,           MOD_LONG },
        { "float",      &fp_type,       0 },
        { "double",     &fp_type,       MOD_LONG },
        { "signed",     NULL,           MOD_SIGNED | MOD_EXPLICITLY_SIGNED },
        { "__signed",   NULL,           MOD_SIGNED | MOD_EXPLICITLY_SIGNED },
        { "__signed__", NULL,           MOD_SIGNED | MOD_EXPLICITLY_SIGNED },
        { "unsigned",   NULL,           MOD_UNSIGNED },
        { "__label__",  &label_ctype,   MOD_LABEL | MOD_UNSIGNED },
        { "_Bool",      &bool_ctype,    MOD_UNSIGNED },

        /* Predeclared types */
        { "__builtin_va_list", &int_type, 0 },

        { NULL,         NULL,           0 }
};

static struct symbol_op constant_p_op = {
        .evaluate = evaluate_to_integer,
        .expand = expand_constant_p
};

static struct symbol_op safe_p_op = {
        .evaluate = evaluate_to_integer,
        .expand = expand_safe_p
};

static struct symbol_op warning_op = {
        .evaluate = evaluate_to_integer,
        .expand = expand_warning
};

static struct symbol_op expect_op = {
        .evaluate = evaluate_expect,
        .expand = expand_expect
};

static struct symbol_op choose_op = {
        .evaluate = evaluate_choose,
        .args = arguments_choose,
};

/*
 * Builtin functions
 */
static struct symbol builtin_fn_type = { .type = SYM_FN /* , .variadic =1 */ };
static struct sym_init eval_init_table[] = {
        { "__builtin_constant_p", &builtin_fn_type, MOD_TOPLEVEL, &constant_p_op },
        { "__builtin_safe_p", &builtin_fn_type, MOD_TOPLEVEL, &safe_p_op },
        { "__builtin_warning", &builtin_fn_type, MOD_TOPLEVEL, &warning_op },
        { "__builtin_expect", &builtin_fn_type, MOD_TOPLEVEL, &expect_op },
        { "__builtin_choose_expr", &builtin_fn_type, MOD_TOPLEVEL, &choose_op },
        { NULL,         NULL,           0 }
};


/*
 * Abstract types
 */
struct symbol   int_type,
                fp_type;

/*
 * C types (i.e. actual instances that the abstract types
 * can map onto)
 */
struct symbol   bool_ctype, void_ctype, type_ctype,
                char_ctype, schar_ctype, uchar_ctype,
                short_ctype, sshort_ctype, ushort_ctype,
                int_ctype, sint_ctype, uint_ctype,
                long_ctype, slong_ctype, ulong_ctype,
                llong_ctype, sllong_ctype, ullong_ctype,
                float_ctype, double_ctype, ldouble_ctype,
                string_ctype, ptr_ctype, lazy_ptr_ctype,
                incomplete_ctype, label_ctype, bad_ctype,
                null_ctype;

struct symbol   zero_int;

#define __INIT_IDENT(str, res) { .len = sizeof(str)-1, .name = str, .reserved = res }
#define __IDENT(n,str,res) \
        struct ident n  = __INIT_IDENT(str,res)

#include "ident-list.h"

void init_symbols(void)
{
        int stream = init_stream("builtin", -1, includepath);
        struct sym_init *ptr;

#define __IDENT(n,str,res) \
        hash_ident(&n)
#include "ident-list.h"

        init_parser(stream);
        for (ptr = symbol_init_table; ptr->name; ptr++) {
                struct symbol *sym;
                sym = create_symbol(stream, ptr->name, SYM_NODE, NS_TYPEDEF);
                sym->ident->reserved = 1;
                sym->ctype.base_type = ptr->base_type;
                sym->ctype.modifiers = ptr->modifiers;
        }

        builtin_fn_type.variadic = 1;
        for (ptr = eval_init_table; ptr->name; ptr++) {
                struct symbol *sym;
                sym = create_symbol(stream, ptr->name, SYM_NODE, NS_SYMBOL);
                sym->ctype.base_type = ptr->base_type;
                sym->ctype.modifiers = ptr->modifiers;
                sym->op = ptr->op;
        }
}

#define MOD_ESIGNED (MOD_SIGNED | MOD_EXPLICITLY_SIGNED)
#define MOD_LL (MOD_LONG | MOD_LONGLONG)
static const struct ctype_declare {
        struct symbol *ptr;
        enum type type;
        unsigned long modifiers;
        int *bit_size;
        int *maxalign;
        struct symbol *base_type;
} ctype_declaration[] = {
        { &bool_ctype,      SYM_BASETYPE, MOD_UNSIGNED,             &bits_in_bool,           &max_int_alignment, &int_type },
        { &void_ctype,      SYM_BASETYPE, 0,                        NULL,                    NULL,               NULL },
        { &type_ctype,      SYM_BASETYPE, MOD_TYPE,                 NULL,                    NULL,               NULL },
        { &incomplete_ctype,SYM_BASETYPE, 0,                        NULL,                    NULL,               NULL },
        { &bad_ctype,       SYM_BASETYPE, 0,                        NULL,                    NULL,               NULL },

        { &char_ctype,      SYM_BASETYPE, MOD_SIGNED | MOD_CHAR,    &bits_in_char,           &max_int_alignment, &int_type },
        { &schar_ctype,     SYM_BASETYPE, MOD_ESIGNED | MOD_CHAR,   &bits_in_char,           &max_int_alignment, &int_type },
        { &uchar_ctype,     SYM_BASETYPE, MOD_UNSIGNED | MOD_CHAR,  &bits_in_char,           &max_int_alignment, &int_type },
        { &short_ctype,     SYM_BASETYPE, MOD_SIGNED | MOD_SHORT,   &bits_in_short,          &max_int_alignment, &int_type },
        { &sshort_ctype,    SYM_BASETYPE, MOD_ESIGNED | MOD_SHORT,  &bits_in_short,          &max_int_alignment, &int_type },
        { &ushort_ctype,    SYM_BASETYPE, MOD_UNSIGNED | MOD_SHORT, &bits_in_short,          &max_int_alignment, &int_type },
        { &int_ctype,       SYM_BASETYPE, MOD_SIGNED,               &bits_in_int,            &max_int_alignment, &int_type },
        { &sint_ctype,      SYM_BASETYPE, MOD_ESIGNED,              &bits_in_int,            &max_int_alignment, &int_type },
        { &uint_ctype,      SYM_BASETYPE, MOD_UNSIGNED,             &bits_in_int,            &max_int_alignment, &int_type },
        { &long_ctype,      SYM_BASETYPE, MOD_SIGNED | MOD_LONG,    &bits_in_long,           &max_int_alignment, &int_type },
        { &slong_ctype,     SYM_BASETYPE, MOD_ESIGNED | MOD_LONG,   &bits_in_long,           &max_int_alignment, &int_type },
        { &ulong_ctype,     SYM_BASETYPE, MOD_UNSIGNED | MOD_LONG,  &bits_in_long,           &max_int_alignment, &int_type },
        { &llong_ctype,     SYM_BASETYPE, MOD_SIGNED | MOD_LL,      &bits_in_longlong,       &max_int_alignment, &int_type },
        { &sllong_ctype,    SYM_BASETYPE, MOD_ESIGNED | MOD_LL,     &bits_in_longlong,       &max_int_alignment, &int_type },
        { &ullong_ctype,    SYM_BASETYPE, MOD_UNSIGNED | MOD_LL,    &bits_in_longlong,       &max_int_alignment, &int_type },

        { &float_ctype,     SYM_BASETYPE,  0,                       &bits_in_float,          &max_fp_alignment,  &fp_type },
        { &double_ctype,    SYM_BASETYPE, MOD_LONG,                 &bits_in_double,         &max_fp_alignment,  &fp_type },
        { &ldouble_ctype,   SYM_BASETYPE, MOD_LONG | MOD_LONGLONG,  &bits_in_longdouble,     &max_fp_alignment,  &fp_type },

        { &string_ctype,    SYM_PTR,      0,                        &bits_in_pointer,        &pointer_alignment, &char_ctype },
        { &ptr_ctype,       SYM_PTR,      0,                        &bits_in_pointer,        &pointer_alignment, &void_ctype },
        { &null_ctype,      SYM_PTR,      0,                        &bits_in_pointer,        &pointer_alignment, &void_ctype },
        { &label_ctype,     SYM_PTR,      0,                        &bits_in_pointer,        &pointer_alignment, &void_ctype },
        { &lazy_ptr_ctype,  SYM_PTR,      0,                        &bits_in_pointer,        &pointer_alignment, &void_ctype },
        { NULL, }
};
#undef MOD_LL
#undef MOD_ESIGNED

void init_ctype(void)
{
        const struct ctype_declare *ctype;

        for (ctype = ctype_declaration ; ctype->ptr; ctype++) {
                struct symbol *sym = ctype->ptr;
                unsigned long bit_size = ctype->bit_size ? *ctype->bit_size : -1;
                unsigned long maxalign = ctype->maxalign ? *ctype->maxalign : 0;
                unsigned long alignment = (bit_size + 7) >> 3;

                if (alignment > maxalign)
                        alignment = maxalign;
                sym->type = ctype->type;
                sym->bit_size = bit_size;
                sym->ctype.alignment = alignment;
                sym->ctype.base_type = ctype->base_type;
                sym->ctype.modifiers = ctype->modifiers;
        }
}