/*
 * Copyright (C) 2012
 *     Wolfgang Bumiller
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "gmqcc.h"
#include "ast.h"

#define ast_instantiate(T, ctx, destroyfn)                          \
    T* self = (T*)mem_a(sizeof(T));                                 \
    if (!self) {                                                    \
        return NULL;                                                \
    }                                                               \
    ast_node_init((ast_node*)self, ctx, TYPE_##T);                  \
    ( (ast_node*)self )->node.destroy = (ast_node_delete*)destroyfn

/* error handling */
static void asterror(lex_ctx ctx, const char *msg, ...)
{
    va_list ap;
    va_start(ap, msg);
    con_cvprintmsg((void*)&ctx, LVL_ERROR, "error", msg, ap);
    va_end(ap);
}

/* It must not be possible to get here. */
static GMQCC_NORETURN void _ast_node_destroy(ast_node *self)
{
    con_err("ast node missing destroy()\n");
    abort();
}

/* Initialize main ast node aprts */
static void ast_node_init(ast_node *self, lex_ctx ctx, int nodetype)
{
    self->node.context = ctx;
    self->node.destroy = &_ast_node_destroy;
    self->node.keep    = false;
    self->node.nodetype = nodetype;
}

/* General expression initialization */
static void ast_expression_init(ast_expression *self,
                                ast_expression_codegen *codegen)
{
    self->expression.codegen  = codegen;
    self->expression.vtype    = TYPE_VOID;
    self->expression.next     = NULL;
    self->expression.outl     = NULL;
    self->expression.outr     = NULL;
    self->expression.variadic = false;
    self->expression.params   = NULL;
}

static void ast_expression_delete(ast_expression *self)
{
    size_t i;
    if (self->expression.next)
        ast_delete(self->expression.next);
    for (i = 0; i < vec_size(self->expression.params); ++i) {
        ast_delete(self->expression.params[i]);
    }
    vec_free(self->expression.params);
}

static void ast_expression_delete_full(ast_expression *self)
{
    ast_expression_delete(self);
    mem_d(self);
}

ast_value* ast_value_copy(const ast_value *self)
{
    size_t i;
    const ast_expression_common *fromex;
    ast_expression_common *selfex;
    ast_value *cp = ast_value_new(self->expression.node.context, self->name, self->expression.vtype);
    if (self->expression.next) {
        cp->expression.next = ast_type_copy(self->expression.node.context, self->expression.next);
        if (!cp->expression.next) {
            ast_value_delete(cp);
            return NULL;
        }
    }
    fromex   = &self->expression;
    selfex = &cp->expression;
    selfex->variadic = fromex->variadic;
    for (i = 0; i < vec_size(fromex->params); ++i) {
        ast_value *v = ast_value_copy(fromex->params[i]);
        if (!v) {
            ast_value_delete(cp);
            return NULL;
        }
        vec_push(selfex->params, v);
    }
    return cp;
}

bool ast_type_adopt_impl(ast_expression *self, const ast_expression *other)
{
    size_t i;
    const ast_expression_common *fromex;
    ast_expression_common *selfex;
    self->expression.vtype = other->expression.vtype;
    if (other->expression.next) {
        self->expression.next = (ast_expression*)ast_type_copy(ast_ctx(self), other->expression.next);
        if (!self->expression.next)
            return false;
    }
    fromex   = &other->expression;
    selfex = &self->expression;
    selfex->variadic = fromex->variadic;
    for (i = 0; i < vec_size(fromex->params); ++i) {
        ast_value *v = ast_value_copy(fromex->params[i]);
        if (!v)
            return false;
        vec_push(selfex->params, v);
    }
    return true;
}

static ast_expression* ast_shallow_type(lex_ctx ctx, int vtype)
{
    ast_instantiate(ast_expression, ctx, ast_expression_delete_full);
    ast_expression_init(self, NULL);
    self->expression.codegen = NULL;
    self->expression.next    = NULL;
    self->expression.vtype   = vtype;
    return self;
}

ast_expression* ast_type_copy(lex_ctx ctx, const ast_expression *ex)
{
    size_t i;
    const ast_expression_common *fromex;
    ast_expression_common *selfex;

    if (!ex)
        return NULL;
    else
    {
        ast_instantiate(ast_expression, ctx, ast_expression_delete_full);
        ast_expression_init(self, NULL);

        fromex   = &ex->expression;
        selfex = &self->expression;

        /* This may never be codegen()d */
        selfex->codegen = NULL;

        selfex->vtype = fromex->vtype;
        if (fromex->next)
        {
            selfex->next = ast_type_copy(ctx, fromex->next);
            if (!selfex->next) {
                ast_expression_delete_full(self);
                return NULL;
            }
        }
        else
            selfex->next = NULL;

        selfex->variadic = fromex->variadic;
        for (i = 0; i < vec_size(fromex->params); ++i) {
            ast_value *v = ast_value_copy(fromex->params[i]);
            if (!v) {
                ast_expression_delete_full(self);
                return NULL;
            }
            vec_push(selfex->params, v);
        }

        return self;
    }
}

bool ast_compare_type(ast_expression *a, ast_expression *b)
{
    if (a->expression.vtype != b->expression.vtype)
        return false;
    if (!a->expression.next != !b->expression.next)
        return false;
    if (vec_size(a->expression.params) != vec_size(b->expression.params))
        return false;
    if (a->expression.variadic != b->expression.variadic)
        return false;
    if (vec_size(a->expression.params)) {
        size_t i;
        for (i = 0; i < vec_size(a->expression.params); ++i) {
            if (!ast_compare_type((ast_expression*)a->expression.params[i],
                                  (ast_expression*)b->expression.params[i]))
                return false;
        }
    }
    if (a->expression.next)
        return ast_compare_type(a->expression.next, b->expression.next);
    return true;
}

static size_t ast_type_to_string_impl(ast_expression *e, char *buf, size_t bufsize, size_t pos)
{
    const char *typestr;
    size_t typelen;
    size_t i;

    if (!e) {
        if (pos + 6 >= bufsize)
            goto full;
        strcpy(buf + pos, "(null)");
        return pos + 6;
    }

    if (pos + 1 >= bufsize)
        goto full;

    switch (e->expression.vtype) {
        case TYPE_VARIANT:
            strcpy(buf + pos, "(variant)");
            return pos + 9;

        case TYPE_FIELD:
            buf[pos++] = '.';
            return ast_type_to_string_impl(e->expression.next, buf, bufsize, pos);

        case TYPE_POINTER:
            if (pos + 3 >= bufsize)
                goto full;
            buf[pos++] = '*';
            buf[pos++] = '(';
            pos = ast_type_to_string_impl(e->expression.next, buf, bufsize, pos);
            if (pos + 1 >= bufsize)
                goto full;
            buf[pos++] = ')';
            return pos;

        case TYPE_FUNCTION:
            pos = ast_type_to_string_impl(e->expression.next, buf, bufsize, pos);
            if (pos + 2 >= bufsize)
                goto full;
            if (!vec_size(e->expression.params)) {
                buf[pos++] = '(';
                buf[pos++] = ')';
                return pos;
            }
            buf[pos++] = '(';
            pos = ast_type_to_string_impl((ast_expression*)(e->expression.params[0]), buf, bufsize, pos);
            for (i = 1; i < vec_size(e->expression.params); ++i) {
                if (pos + 2 >= bufsize)
                    goto full;
                buf[pos++] = ',';
                buf[pos++] = ' ';
                pos = ast_type_to_string_impl((ast_expression*)(e->expression.params[i]), buf, bufsize, pos);
            }
            if (pos + 1 >= bufsize)
                goto full;
            buf[pos++] = ')';
            return pos;

        case TYPE_ARRAY:
            pos = ast_type_to_string_impl(e->expression.next, buf, bufsize, pos);
            if (pos + 1 >= bufsize)
                goto full;
            buf[pos++] = '[';
            pos += snprintf(buf + pos, bufsize - pos - 1, "%i", (int)e->expression.count);
            if (pos + 1 >= bufsize)
                goto full;
            buf[pos++] = ']';
            return pos;

        default:
            typestr = type_name[e->expression.vtype];
            typelen = strlen(typestr);
            if (pos + typelen >= bufsize)
                goto full;
            strcpy(buf + pos, typestr);
            return pos + typelen;
    }

full:
    buf[bufsize-3] = '.';
    buf[bufsize-2] = '.';
    buf[bufsize-1] = '.';
    return bufsize;
}

void ast_type_to_string(ast_expression *e, char *buf, size_t bufsize)
{
    size_t pos = ast_type_to_string_impl(e, buf, bufsize-1, 0);
    buf[pos] = 0;
}

ast_value* ast_value_new(lex_ctx ctx, const char *name, int t)
{
    ast_instantiate(ast_value, ctx, ast_value_delete);
    ast_expression_init((ast_expression*)self,
                        (ast_expression_codegen*)&ast_value_codegen);
    self->expression.node.keep = true; /* keep */

    self->name = name ? util_strdup(name) : NULL;
    self->expression.vtype = t;
    self->expression.next  = NULL;
    self->isconst = false;
    self->uses    = 0;
    memset(&self->constval, 0, sizeof(self->constval));

    self->ir_v           = NULL;
    self->ir_values      = NULL;
    self->ir_value_count = 0;

    self->setter = NULL;
    self->getter = NULL;

    return self;
}

void ast_value_delete(ast_value* self)
{
    if (self->name)
        mem_d((void*)self->name);
    if (self->isconst) {
        switch (self->expression.vtype)
        {
        case TYPE_STRING:
            mem_d((void*)self->constval.vstring);
            break;
        case TYPE_FUNCTION:
            /* unlink us from the function node */
            self->constval.vfunc->vtype = NULL;
            break;
        /* NOTE: delete function? currently collected in
         * the parser structure
         */
        default:
            break;
        }
    }
    if (self->ir_values)
        mem_d(self->ir_values);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

void ast_value_params_add(ast_value *self, ast_value *p)
{
    vec_push(self->expression.params, p);
}

bool ast_value_set_name(ast_value *self, const char *name)
{
    if (self->name)
        mem_d((void*)self->name);
    self->name = util_strdup(name);
    return !!self->name;
}

ast_binary* ast_binary_new(lex_ctx ctx, int op,
                           ast_expression* left, ast_expression* right)
{
    ast_instantiate(ast_binary, ctx, ast_binary_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_binary_codegen);

    self->op = op;
    self->left = left;
    self->right = right;

    if (op >= INSTR_EQ_F && op <= INSTR_GT)
        self->expression.vtype = TYPE_FLOAT;
    else if (op == INSTR_AND || op == INSTR_OR ||
             op == INSTR_BITAND || op == INSTR_BITOR)
        self->expression.vtype = TYPE_FLOAT;
    else if (op == INSTR_MUL_VF || op == INSTR_MUL_FV)
        self->expression.vtype = TYPE_VECTOR;
    else if (op == INSTR_MUL_V)
        self->expression.vtype = TYPE_FLOAT;
    else
        self->expression.vtype = left->expression.vtype;

    return self;
}

void ast_binary_delete(ast_binary *self)
{
    ast_unref(self->left);
    ast_unref(self->right);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_binstore* ast_binstore_new(lex_ctx ctx, int storop, int op,
                               ast_expression* left, ast_expression* right)
{
    ast_instantiate(ast_binstore, ctx, ast_binstore_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_binstore_codegen);

    self->opstore = storop;
    self->opbin   = op;
    self->dest    = left;
    self->source  = right;

    self->expression.vtype = left->expression.vtype;
    if (left->expression.next) {
        self->expression.next = ast_type_copy(ctx, left);
        if (!self->expression.next) {
            ast_delete(self);
            return NULL;
        }
    }
    else
        self->expression.next = NULL;

    return self;
}

void ast_binstore_delete(ast_binstore *self)
{
    ast_unref(self->dest);
    ast_unref(self->source);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_unary* ast_unary_new(lex_ctx ctx, int op,
                         ast_expression *expr)
{
    ast_instantiate(ast_unary, ctx, ast_unary_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_unary_codegen);

    self->op = op;
    self->operand = expr;

    if (op >= INSTR_NOT_F && op <= INSTR_NOT_FNC) {
        self->expression.vtype = TYPE_FLOAT;
    } else
        asterror(ctx, "cannot determine type of unary operation %s", asm_instr[op].m);

    return self;
}

void ast_unary_delete(ast_unary *self)
{
    ast_unref(self->operand);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_return* ast_return_new(lex_ctx ctx, ast_expression *expr)
{
    ast_instantiate(ast_return, ctx, ast_return_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_return_codegen);

    self->operand = expr;

    return self;
}

void ast_return_delete(ast_return *self)
{
    if (self->operand)
        ast_unref(self->operand);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_entfield* ast_entfield_new(lex_ctx ctx, ast_expression *entity, ast_expression *field)
{
    if (field->expression.vtype != TYPE_FIELD) {
        asterror(ctx, "ast_entfield_new with expression not of type field");
        return NULL;
    }
    return ast_entfield_new_force(ctx, entity, field, field->expression.next);
}

ast_entfield* ast_entfield_new_force(lex_ctx ctx, ast_expression *entity, ast_expression *field, const ast_expression *outtype)
{
    ast_instantiate(ast_entfield, ctx, ast_entfield_delete);

    if (!outtype) {
        mem_d(self);
        /* Error: field has no type... */
        return NULL;
    }

    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_entfield_codegen);

    self->entity = entity;
    self->field  = field;

    if (!ast_type_adopt(self, outtype)) {
        ast_entfield_delete(self);
        return NULL;
    }

    return self;
}

void ast_entfield_delete(ast_entfield *self)
{
    ast_unref(self->entity);
    ast_unref(self->field);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_member* ast_member_new(lex_ctx ctx, ast_expression *owner, unsigned int field)
{
    ast_instantiate(ast_member, ctx, ast_member_delete);
    if (field >= 3) {
        mem_d(self);
        return NULL;
    }

    if (owner->expression.vtype != TYPE_VECTOR &&
        owner->expression.vtype != TYPE_FIELD) {
        asterror(ctx, "member-access on an invalid owner of type %s", type_name[owner->expression.vtype]);
        mem_d(self);
        return NULL;
    }

    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_member_codegen);
    self->expression.node.keep = true; /* keep */

    if (owner->expression.vtype == TYPE_VECTOR) {
        self->expression.vtype = TYPE_FLOAT;
        self->expression.next  = NULL;
    } else {
        self->expression.vtype = TYPE_FIELD;
        self->expression.next = ast_shallow_type(ctx, TYPE_FLOAT);
    }

    self->owner = owner;
    self->field = field;

    return self;
}

void ast_member_delete(ast_member *self)
{
    /* The owner is always an ast_value, which has .keep=true,
     * also: ast_members are usually deleted after the owner, thus
     * this will cause invalid access
    ast_unref(self->owner);
     * once we allow (expression).x to access a vector-member, we need
     * to change this: preferably by creating an alternate ast node for this
     * purpose that is not garbage-collected.
    */
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_array_index* ast_array_index_new(lex_ctx ctx, ast_expression *array, ast_expression *index)
{
    ast_expression *outtype;
    ast_instantiate(ast_array_index, ctx, ast_array_index_delete);

    outtype = array->expression.next;
    if (!outtype) {
        mem_d(self);
        /* Error: field has no type... */
        return NULL;
    }

    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_array_index_codegen);

    self->array = array;
    self->index = index;

    if (!ast_type_adopt(self, outtype)) {
        ast_array_index_delete(self);
        return NULL;
    }
    if (array->expression.vtype == TYPE_FIELD && outtype->expression.vtype == TYPE_ARRAY) {
        if (self->expression.vtype != TYPE_ARRAY) {
            asterror(ast_ctx(self), "array_index node on type");
            ast_array_index_delete(self);
            return NULL;
        }
        self->array = outtype;
        self->expression.vtype = TYPE_FIELD;
    }

    return self;
}

void ast_array_index_delete(ast_array_index *self)
{
    ast_unref(self->array);
    ast_unref(self->index);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_ifthen* ast_ifthen_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
{
    ast_instantiate(ast_ifthen, ctx, ast_ifthen_delete);
    if (!ontrue && !onfalse) {
        /* because it is invalid */
        mem_d(self);
        return NULL;
    }
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ifthen_codegen);

    self->cond     = cond;
    self->on_true  = ontrue;
    self->on_false = onfalse;

    return self;
}

void ast_ifthen_delete(ast_ifthen *self)
{
    ast_unref(self->cond);
    if (self->on_true)
        ast_unref(self->on_true);
    if (self->on_false)
        ast_unref(self->on_false);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_ternary* ast_ternary_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
{
    ast_instantiate(ast_ternary, ctx, ast_ternary_delete);
    /* This time NEITHER must be NULL */
    if (!ontrue || !onfalse) {
        mem_d(self);
        return NULL;
    }
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ternary_codegen);

    self->cond     = cond;
    self->on_true  = ontrue;
    self->on_false = onfalse;
    self->phi_out  = NULL;

    return self;
}

void ast_ternary_delete(ast_ternary *self)
{
    ast_unref(self->cond);
    ast_unref(self->on_true);
    ast_unref(self->on_false);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_loop* ast_loop_new(lex_ctx ctx,
                       ast_expression *initexpr,
                       ast_expression *precond,
                       ast_expression *postcond,
                       ast_expression *increment,
                       ast_expression *body)
{
    ast_instantiate(ast_loop, ctx, ast_loop_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_loop_codegen);

    self->initexpr  = initexpr;
    self->precond   = precond;
    self->postcond  = postcond;
    self->increment = increment;
    self->body      = body;

    return self;
}

void ast_loop_delete(ast_loop *self)
{
    if (self->initexpr)
        ast_unref(self->initexpr);
    if (self->precond)
        ast_unref(self->precond);
    if (self->postcond)
        ast_unref(self->postcond);
    if (self->increment)
        ast_unref(self->increment);
    if (self->body)
        ast_unref(self->body);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_breakcont* ast_breakcont_new(lex_ctx ctx, bool iscont)
{
    ast_instantiate(ast_breakcont, ctx, ast_breakcont_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_breakcont_codegen);

    self->is_continue = iscont;

    return self;
}

void ast_breakcont_delete(ast_breakcont *self)
{
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_switch* ast_switch_new(lex_ctx ctx, ast_expression *op)
{
    ast_instantiate(ast_switch, ctx, ast_switch_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_switch_codegen);

    self->operand = op;
    self->cases   = NULL;

    return self;
}

void ast_switch_delete(ast_switch *self)
{
    size_t i;
    ast_unref(self->operand);

    for (i = 0; i < vec_size(self->cases); ++i) {
        if (self->cases[i].value)
            ast_unref(self->cases[i].value);
        ast_unref(self->cases[i].code);
    }
    vec_free(self->cases);

    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_call* ast_call_new(lex_ctx ctx,
                       ast_expression *funcexpr)
{
    ast_instantiate(ast_call, ctx, ast_call_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_call_codegen);

    self->params = NULL;
    self->func   = funcexpr;

    self->expression.vtype = funcexpr->expression.next->expression.vtype;
    if (funcexpr->expression.next->expression.next)
        self->expression.next = ast_type_copy(ctx, funcexpr->expression.next->expression.next);

    return self;
}

void ast_call_delete(ast_call *self)
{
    size_t i;
    for (i = 0; i < vec_size(self->params); ++i)
        ast_unref(self->params[i]);
    vec_free(self->params);

    if (self->func)
        ast_unref(self->func);

    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

bool ast_call_check_types(ast_call *self)
{
    size_t i;
    bool   retval = true;
    const  ast_expression *func = self->func;
    size_t count = vec_size(self->params);
    if (count > vec_size(func->expression.params))
        count = vec_size(func->expression.params);

    for (i = 0; i < count; ++i) {
        if (!ast_compare_type(self->params[i], (ast_expression*)(func->expression.params[i]))) {
            asterror(ast_ctx(self), "invalid type for parameter %u in function call",
                     (unsigned int)(i+1));
            /* we don't immediately return */
            retval = false;
        }
    }
    return retval;
}

ast_store* ast_store_new(lex_ctx ctx, int op,
                         ast_expression *dest, ast_expression *source)
{
    ast_instantiate(ast_store, ctx, ast_store_delete);
    ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);

    self->op = op;
    self->dest = dest;
    self->source = source;

    self->expression.vtype = dest->expression.vtype;
    if (dest->expression.next) {
        self->expression.next = ast_type_copy(ctx, dest);
        if (!self->expression.next) {
            ast_delete(self);
            return NULL;
        }
    }
    else
        self->expression.next = NULL;

    return self;
}

void ast_store_delete(ast_store *self)
{
    ast_unref(self->dest);
    ast_unref(self->source);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

ast_block* ast_block_new(lex_ctx ctx)
{
    ast_instantiate(ast_block, ctx, ast_block_delete);
    ast_expression_init((ast_expression*)self,
                        (ast_expression_codegen*)&ast_block_codegen);

    self->locals  = NULL;
    self->exprs   = NULL;
    self->collect = NULL;

    return self;
}

void ast_block_collect(ast_block *self, ast_expression *expr)
{
    vec_push(self->collect, expr);
    expr->expression.node.keep = true;
}

void ast_block_delete(ast_block *self)
{
    size_t i;
    for (i = 0; i < vec_size(self->exprs); ++i)
        ast_unref(self->exprs[i]);
    vec_free(self->exprs);
    for (i = 0; i < vec_size(self->locals); ++i)
        ast_delete(self->locals[i]);
    vec_free(self->locals);
    for (i = 0; i < vec_size(self->collect); ++i)
        ast_delete(self->collect[i]);
    vec_free(self->collect);
    ast_expression_delete((ast_expression*)self);
    mem_d(self);
}

bool ast_block_set_type(ast_block *self, ast_expression *from)
{
    if (self->expression.next)
        ast_delete(self->expression.next);
    self->expression.vtype = from->expression.vtype;
    if (from->expression.next) {
        self->expression.next = ast_type_copy(self->expression.node.context, from->expression.next);
        if (!self->expression.next)
            return false;
    }
    else
        self->expression.next = NULL;
    return true;
}

ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
{
    ast_instantiate(ast_function, ctx, ast_function_delete);

    if (!vtype ||
        vtype->isconst ||
        vtype->expression.vtype != TYPE_FUNCTION)
    {
        mem_d(self);
        return NULL;
    }

    self->vtype  = vtype;
    self->name   = name ? util_strdup(name) : NULL;
    self->blocks = NULL;

    self->labelcount = 0;
    self->builtin = 0;

    self->ir_func = NULL;
    self->curblock = NULL;

    self->breakblock    = NULL;
    self->continueblock = NULL;

    vtype->isconst = true;
    vtype->constval.vfunc = self;

    return self;
}

void ast_function_delete(ast_function *self)
{
    size_t i;
    if (self->name)
        mem_d((void*)self->name);
    if (self->vtype) {
        /* ast_value_delete(self->vtype); */
        self->vtype->isconst = false;
        self->vtype->constval.vfunc = NULL;
        /* We use unref - if it was stored in a global table it is supposed
         * to be deleted from *there*
         */
        ast_unref(self->vtype);
    }
    for (i = 0; i < vec_size(self->blocks); ++i)
        ast_delete(self->blocks[i]);
    vec_free(self->blocks);
    mem_d(self);
}

const char* ast_function_label(ast_function *self, const char *prefix)
{
    size_t id;
    size_t len;
    char  *from;

    if (!opts_dump)
        return NULL;

    id  = (self->labelcount++);
    len = strlen(prefix);

    from = self->labelbuf + sizeof(self->labelbuf)-1;
    *from-- = 0;
    do {
        unsigned int digit = id % 10;
        *from = digit + '0';
        id /= 10;
    } while (id);
    memcpy(from - len, prefix, len);
    return from - len;
}

/*********************************************************************/
/* AST codegen part
 * by convention you must never pass NULL to the 'ir_value **out'
 * parameter. If you really don't care about the output, pass a dummy.
 * But I can't imagine a pituation where the output is truly unnecessary.
 */

bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
{
    /* NOTE: This is the codegen for a variable used in an expression.
     * It is not the codegen to generate the value. For this purpose,
     * ast_local_codegen and ast_global_codegen are to be used before this
     * is executed. ast_function_codegen should take care of its locals,
     * and the ast-user should take care of ast_global_codegen to be used
     * on all the globals.
     */
    if (!self->ir_v) {
        char typename[1024];
        ast_type_to_string((ast_expression*)self, typename, sizeof(typename));
        asterror(ast_ctx(self), "ast_value used before generated %s %s", typename, self->name);
        return false;
    }
    *out = self->ir_v;
    return true;
}

bool ast_global_codegen(ast_value *self, ir_builder *ir, bool isfield)
{
    ir_value *v = NULL;

    if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
    {
        ir_function *func = ir_builder_create_function(ir, self->name, self->expression.next->expression.vtype);
        if (!func)
            return false;
        func->context = ast_ctx(self);
        func->value->context = ast_ctx(self);

        self->constval.vfunc->ir_func = func;
        self->ir_v = func->value;
        /* The function is filled later on ast_function_codegen... */
        return true;
    }

    if (isfield && self->expression.vtype == TYPE_FIELD) {
        ast_expression *fieldtype = self->expression.next;

        if (self->isconst) {
            asterror(ast_ctx(self), "TODO: constant field pointers with value");
            goto error;
        }

        if (fieldtype->expression.vtype == TYPE_ARRAY) {
            size_t ai;
            char   *name;
            size_t  namelen;

            ast_expression_common *elemtype;
            int                    vtype;
            ast_value             *array = (ast_value*)fieldtype;

            if (!ast_istype(fieldtype, ast_value)) {
                asterror(ast_ctx(self), "internal error: ast_value required");
                return false;
            }

            /* we are lame now - considering the way QC works we won't tolerate arrays > 1024 elements */
            if (!array->expression.count || array->expression.count > opts_max_array_size)
                asterror(ast_ctx(self), "Invalid array of size %lu", (unsigned long)array->expression.count);

            elemtype = &array->expression.next->expression;
            vtype = elemtype->vtype;

            v = ir_builder_create_field(ir, self->name, vtype);
            if (!v) {
                asterror(ast_ctx(self), "ir_builder_create_global failed");
                return false;
            }
            if (vtype == TYPE_FIELD)
                v->fieldtype = elemtype->next->expression.vtype;
            v->context = ast_ctx(self);
            array->ir_v = self->ir_v = v;

            namelen = strlen(self->name);
            name    = (char*)mem_a(namelen + 16);
            strcpy(name, self->name);

            array->ir_values = (ir_value**)mem_a(sizeof(array->ir_values[0]) * array->expression.count);
            array->ir_values[0] = v;
            for (ai = 1; ai < array->expression.count; ++ai) {
                snprintf(name + namelen, 16, "[%u]", (unsigned int)ai);
                array->ir_values[ai] = ir_builder_create_field(ir, name, vtype);
                if (!array->ir_values[ai]) {
                    mem_d(name);
                    asterror(ast_ctx(self), "ir_builder_create_global failed");
                    return false;
                }
                if (vtype == TYPE_FIELD)
                    array->ir_values[ai]->fieldtype = elemtype->next->expression.vtype;
                array->ir_values[ai]->context = ast_ctx(self);
            }
            mem_d(name);
        }
        else
        {
            v = ir_builder_create_field(ir, self->name, self->expression.next->expression.vtype);
            if (!v)
                return false;
            v->context = ast_ctx(self);
            self->ir_v = v;
        }
        return true;
    }

    if (self->expression.vtype == TYPE_ARRAY) {
        size_t ai;
        char   *name;
        size_t  namelen;

        ast_expression_common *elemtype = &self->expression.next->expression;
        int vtype = elemtype->vtype;

        /* same as with field arrays */
        if (!self->expression.count || self->expression.count > opts_max_array_size)
            asterror(ast_ctx(self), "Invalid array of size %lu", (unsigned long)self->expression.count);

        v = ir_builder_create_global(ir, self->name, vtype);
        if (!v) {
            asterror(ast_ctx(self), "ir_builder_create_global failed");
            return false;
        }
        if (vtype == TYPE_FIELD)
            v->fieldtype = elemtype->next->expression.vtype;
        v->context = ast_ctx(self);

        namelen = strlen(self->name);
        name    = (char*)mem_a(namelen + 16);
        strcpy(name, self->name);

        self->ir_values = (ir_value**)mem_a(sizeof(self->ir_values[0]) * self->expression.count);
        self->ir_values[0] = v;
        for (ai = 1; ai < self->expression.count; ++ai) {
            snprintf(name + namelen, 16, "[%u]", (unsigned int)ai);
            self->ir_values[ai] = ir_builder_create_global(ir, name, vtype);
            if (!self->ir_values[ai]) {
                mem_d(name);
                asterror(ast_ctx(self), "ir_builder_create_global failed");
                return false;
            }
            if (vtype == TYPE_FIELD)
                self->ir_values[ai]->fieldtype = elemtype->next->expression.vtype;
            self->ir_values[ai]->context = ast_ctx(self);
        }
        mem_d(name);
    }
    else
    {
        /* Arrays don't do this since there's no "array" value which spans across the
         * whole thing.
         */
        v = ir_builder_create_global(ir, self->name, self->expression.vtype);
        if (!v) {
            asterror(ast_ctx(self), "ir_builder_create_global failed");
            return false;
        }
        if (self->expression.vtype == TYPE_FIELD)
            v->fieldtype = self->expression.next->expression.vtype;
        v->context = ast_ctx(self);
    }

    if (self->isconst) {
        switch (self->expression.vtype)
        {
            case TYPE_FLOAT:
                if (!ir_value_set_float(v, self->constval.vfloat))
                    goto error;
                break;
            case TYPE_VECTOR:
                if (!ir_value_set_vector(v, self->constval.vvec))
                    goto error;
                break;
            case TYPE_STRING:
                if (!ir_value_set_string(v, self->constval.vstring))
                    goto error;
                break;
            case TYPE_ARRAY:
                asterror(ast_ctx(self), "TODO: global constant array");
                break;
            case TYPE_FUNCTION:
                asterror(ast_ctx(self), "global of type function not properly generated");
                goto error;
                /* Cannot generate an IR value for a function,
                 * need a pointer pointing to a function rather.
                 */
            default:
                asterror(ast_ctx(self), "TODO: global constant type %i", self->expression.vtype);
                break;
        }
    }

    /* link us to the ir_value */
    self->ir_v = v;
    return true;

error: /* clean up */
    ir_value_delete(v);
    return false;
}

bool ast_local_codegen(ast_value *self, ir_function *func, bool param)
{
    ir_value *v = NULL;
    if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
    {
        /* Do we allow local functions? I think not...
         * this is NOT a function pointer atm.
         */
        return false;
    }

    if (self->expression.vtype == TYPE_ARRAY) {
        size_t ai;
        char   *name;
        size_t  namelen;

        ast_expression_common *elemtype = &self->expression.next->expression;
        int vtype = elemtype->vtype;

        if (param) {
            asterror(ast_ctx(self), "array-parameters are not supported");
            return false;
        }

        /* we are lame now - considering the way QC works we won't tolerate arrays > 1024 elements */
        if (!self->expression.count || self->expression.count > opts_max_array_size) {
            asterror(ast_ctx(self), "Invalid array of size %lu", (unsigned long)self->expression.count);
        }

        self->ir_values = (ir_value**)mem_a(sizeof(self->ir_values[0]) * self->expression.count);
        if (!self->ir_values) {
            asterror(ast_ctx(self), "failed to allocate array values");
            return false;
        }

        v = ir_function_create_local(func, self->name, vtype, param);
        if (!v) {
            asterror(ast_ctx(self), "ir_function_create_local failed");
            return false;
        }
        if (vtype == TYPE_FIELD)
            v->fieldtype = elemtype->next->expression.vtype;
        v->context = ast_ctx(self);

        namelen = strlen(self->name);
        name    = (char*)mem_a(namelen + 16);
        strcpy(name, self->name);

        self->ir_values[0] = v;
        for (ai = 1; ai < self->expression.count; ++ai) {
            snprintf(name + namelen, 16, "[%u]", (unsigned int)ai);
            self->ir_values[ai] = ir_function_create_local(func, name, vtype, param);
            if (!self->ir_values[ai]) {
                asterror(ast_ctx(self), "ir_builder_create_global failed");
                return false;
            }
            if (vtype == TYPE_FIELD)
                self->ir_values[ai]->fieldtype = elemtype->next->expression.vtype;
            self->ir_values[ai]->context = ast_ctx(self);
        }
    }
    else
    {
        v = ir_function_create_local(func, self->name, self->expression.vtype, param);
        if (!v)
            return false;
        if (self->expression.vtype == TYPE_FIELD)
            v->fieldtype = self->expression.next->expression.vtype;
        v->context = ast_ctx(self);
    }

    /* A constant local... hmmm...
     * I suppose the IR will have to deal with this
     */
    if (self->isconst) {
        switch (self->expression.vtype)
        {
            case TYPE_FLOAT:
                if (!ir_value_set_float(v, self->constval.vfloat))
                    goto error;
                break;
            case TYPE_VECTOR:
                if (!ir_value_set_vector(v, self->constval.vvec))
                    goto error;
                break;
            case TYPE_STRING:
                if (!ir_value_set_string(v, self->constval.vstring))
                    goto error;
                break;
            default:
                asterror(ast_ctx(self), "TODO: global constant type %i", self->expression.vtype);
                break;
        }
    }

    /* link us to the ir_value */
    self->ir_v = v;

    if (self->setter) {
        if (!ast_global_codegen(self->setter, func->owner, false) ||
            !ast_function_codegen(self->setter->constval.vfunc, func->owner) ||
            !ir_function_finalize(self->setter->constval.vfunc->ir_func))
            return false;
    }
    if (self->getter) {
        if (!ast_global_codegen(self->getter, func->owner, false) ||
            !ast_function_codegen(self->getter->constval.vfunc, func->owner) ||
            !ir_function_finalize(self->getter->constval.vfunc->ir_func))
            return false;
    }
    return true;

error: /* clean up */
    ir_value_delete(v);
    return false;
}

bool ast_function_codegen(ast_function *self, ir_builder *ir)
{
    ir_function *irf;
    ir_value    *dummy;
    ast_expression_common *ec;
    size_t    i;

    irf = self->ir_func;
    if (!irf) {
        asterror(ast_ctx(self), "ast_function's related ast_value was not generated yet");
        return false;
    }

    /* fill the parameter list */
    ec = &self->vtype->expression;
    for (i = 0; i < vec_size(ec->params); ++i)
    {
        vec_push(irf->params, ec->params[i]->expression.vtype);
        if (!self->builtin) {
            if (!ast_local_codegen(ec->params[i], self->ir_func, true))
                return false;
        }
    }

    if (self->builtin) {
        irf->builtin = self->builtin;
        return true;
    }

    if (!vec_size(self->blocks)) {
        asterror(ast_ctx(self), "function `%s` has no body", self->name);
        return false;
    }

    self->curblock = ir_function_create_block(irf, "entry");
    if (!self->curblock) {
        asterror(ast_ctx(self), "failed to allocate entry block for `%s`", self->name);
        return false;
    }

    for (i = 0; i < vec_size(self->blocks); ++i) {
        ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
        if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
            return false;
    }

    /* TODO: check return types */
    if (!self->curblock->is_return)
    {
        return ir_block_create_return(self->curblock, NULL);
        /* From now on the parser has to handle this situation */
#if 0
        if (!self->vtype->expression.next ||
            self->vtype->expression.next->expression.vtype == TYPE_VOID)
        {
            return ir_block_create_return(self->curblock, NULL);
        }
        else
        {
            /* error("missing return"); */
            asterror(ast_ctx(self), "function `%s` missing return value", self->name);
            return false;
        }
#endif
    }
    return true;
}

/* Note, you will not see ast_block_codegen generate ir_blocks.
 * To the AST and the IR, blocks are 2 different things.
 * In the AST it represents a block of code, usually enclosed in
 * curly braces {...}.
 * While in the IR it represents a block in terms of control-flow.
 */
bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
{
    size_t i;

    /* We don't use this
     * Note: an ast-representation using the comma-operator
     * of the form: (a, b, c) = x should not assign to c...
     */
    if (lvalue) {
        asterror(ast_ctx(self), "not an l-value (code-block)");
        return false;
    }

    if (self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    /* output is NULL at first, we'll have each expression
     * assign to out output, thus, a comma-operator represention
     * using an ast_block will return the last generated value,
     * so: (b, c) + a  executed both b and c, and returns c,
     * which is then added to a.
     */
    *out = NULL;

    /* generate locals */
    for (i = 0; i < vec_size(self->locals); ++i)
    {
        if (!ast_local_codegen(self->locals[i], func->ir_func, false)) {
            if (opts_debug)
                asterror(ast_ctx(self), "failed to generate local `%s`", self->locals[i]->name);
            return false;
        }
    }

    for (i = 0; i < vec_size(self->exprs); ++i)
    {
        ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
        if (func->curblock->final) {
            asterror(ast_ctx(self->exprs[i]), "unreachable statement");
            return false;
        }
        if (!(*gen)(self->exprs[i], func, false, out))
            return false;
    }

    self->expression.outr = *out;

    return true;
}

bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *left, *right;

    ast_value       *arr;
    ast_value       *idx;
    ast_array_index *ai = NULL;

    if (lvalue && self->expression.outl) {
        *out = self->expression.outl;
        return true;
    }

    if (!lvalue && self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    if (ast_istype(self->dest, ast_array_index))
    {

        ai = (ast_array_index*)self->dest;
        idx = (ast_value*)ai->index;

        if (ast_istype(ai->index, ast_value) && idx->isconst)
            ai = NULL;
    }

    if (ai) {
        /* we need to call the setter */
        ir_value  *iridx, *funval;
        ir_instr  *call;

        if (lvalue) {
            asterror(ast_ctx(self), "array-subscript assignment cannot produce lvalues");
            return false;
        }

        arr = (ast_value*)ai->array;
        if (!ast_istype(ai->array, ast_value) || !arr->setter) {
            asterror(ast_ctx(self), "value has no setter (%s)", arr->name);
            return false;
        }

        cgen = idx->expression.codegen;
        if (!(*cgen)((ast_expression*)(idx), func, false, &iridx))
            return false;

        cgen = arr->setter->expression.codegen;
        if (!(*cgen)((ast_expression*)(arr->setter), func, true, &funval))
            return false;

        cgen = self->source->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
            return false;

        call = ir_block_create_call(func->curblock, ast_function_label(func, "store"), funval);
        if (!call)
            return false;
        ir_call_param(call, iridx);
        ir_call_param(call, right);
        self->expression.outr = right;
    }
    else
    {
        /* regular code */

        cgen = self->dest->expression.codegen;
        /* lvalue! */
        if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
            return false;
        self->expression.outl = left;

        cgen = self->source->expression.codegen;
        /* rvalue! */
        if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
            return false;

        if (!ir_block_create_store_op(func->curblock, self->op, left, right))
            return false;
        self->expression.outr = right;
    }

    /* Theoretically, an assinment returns its left side as an
     * lvalue, if we don't need an lvalue though, we return
     * the right side as an rvalue, otherwise we have to
     * somehow know whether or not we need to dereference the pointer
     * on the left side - that is: OP_LOAD if it was an address.
     * Also: in original QC we cannot OP_LOADP *anyway*.
     */
    *out = (lvalue ? left : right);

    return true;
}

bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *left, *right;

    /* A binary operation cannot yield an l-value */
    if (lvalue) {
        asterror(ast_ctx(self), "not an l-value (binop)");
        return false;
    }

    if (self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    cgen = self->left->expression.codegen;
    /* lvalue! */
    if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
        return false;

    cgen = self->right->expression.codegen;
    /* rvalue! */
    if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
        return false;

    *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
                                 self->op, left, right);
    if (!*out)
        return false;
    self->expression.outr = *out;

    return true;
}

bool ast_binstore_codegen(ast_binstore *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *leftl, *leftr, *right, *bin;

    if (lvalue && self->expression.outl) {
        *out = self->expression.outl;
        return true;
    }

    if (!lvalue && self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    /* for a binstore we need both an lvalue and an rvalue for the left side */
    /* rvalue of destination! */
    cgen = self->dest->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->dest), func, false, &leftr))
        return false;

    /* source as rvalue only */
    cgen = self->source->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
        return false;

    /* now the binary */
    bin = ir_block_create_binop(func->curblock, ast_function_label(func, "binst"),
                                self->opbin, leftr, right);
    self->expression.outr = bin;

    /* now store them */
    cgen = self->dest->expression.codegen;
    /* lvalue of destination */
    if (!(*cgen)((ast_expression*)(self->dest), func, true, &leftl))
        return false;
    self->expression.outl = leftl;

    if (!ir_block_create_store_op(func->curblock, self->opstore, leftl, bin))
        return false;
    self->expression.outr = bin;

    /* Theoretically, an assinment returns its left side as an
     * lvalue, if we don't need an lvalue though, we return
     * the right side as an rvalue, otherwise we have to
     * somehow know whether or not we need to dereference the pointer
     * on the left side - that is: OP_LOAD if it was an address.
     * Also: in original QC we cannot OP_LOADP *anyway*.
     */
    *out = (lvalue ? leftl : bin);

    return true;
}

bool ast_unary_codegen(ast_unary *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *operand;

    /* An unary operation cannot yield an l-value */
    if (lvalue) {
        asterror(ast_ctx(self), "not an l-value (binop)");
        return false;
    }

    if (self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    cgen = self->operand->expression.codegen;
    /* lvalue! */
    if (!(*cgen)((ast_expression*)(self->operand), func, false, &operand))
        return false;

    *out = ir_block_create_unary(func->curblock, ast_function_label(func, "unary"),
                                 self->op, operand);
    if (!*out)
        return false;
    self->expression.outr = *out;

    return true;
}

bool ast_return_codegen(ast_return *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *operand;

    /* In the context of a return operation, we don't actually return
     * anything...
     */
    if (lvalue) {
        asterror(ast_ctx(self), "return-expression is not an l-value");
        return false;
    }

    if (self->expression.outr) {
        asterror(ast_ctx(self), "internal error: ast_return cannot be reused, it bears no result!");
        return false;
    }
    self->expression.outr = (ir_value*)1;

    if (self->operand) {
        cgen = self->operand->expression.codegen;
        /* lvalue! */
        if (!(*cgen)((ast_expression*)(self->operand), func, false, &operand))
            return false;

        if (!ir_block_create_return(func->curblock, operand))
            return false;
    } else {
        if (!ir_block_create_return(func->curblock, NULL))
            return false;
    }

    return true;
}

bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *ent, *field;

    /* This function needs to take the 'lvalue' flag into account!
     * As lvalue we provide a field-pointer, as rvalue we provide the
     * value in a temp.
     */

    if (lvalue && self->expression.outl) {
        *out = self->expression.outl;
        return true;
    }

    if (!lvalue && self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    cgen = self->entity->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
        return false;

    cgen = self->field->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
        return false;

    if (lvalue) {
        /* address! */
        *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
                                            ent, field);
    } else {
        *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
                                             ent, field, self->expression.vtype);
    }
    if (!*out) {
        asterror(ast_ctx(self), "failed to create %s instruction (output type %s)",
                 (lvalue ? "ADDRESS" : "FIELD"),
                 type_name[self->expression.vtype]);
        return false;
    }

    if (lvalue)
        self->expression.outl = *out;
    else
        self->expression.outr = *out;

    /* Hm that should be it... */
    return true;
}

bool ast_member_codegen(ast_member *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value *vec;

    /* in QC this is always an lvalue */
    (void)lvalue;
    if (self->expression.outl) {
        *out = self->expression.outl;
        return true;
    }

    cgen = self->owner->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->owner), func, true, &vec))
        return false;

    if (vec->vtype != TYPE_VECTOR &&
        !(vec->vtype == TYPE_FIELD && self->owner->expression.next->expression.vtype == TYPE_VECTOR))
    {
        return false;
    }

    *out = ir_value_vector_member(vec, self->field);
    self->expression.outl = *out;

    return (*out != NULL);
}

bool ast_array_index_codegen(ast_array_index *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_value *arr;
    ast_value *idx;

    if (!lvalue && self->expression.outr) {
        *out = self->expression.outr;
    }
    if (lvalue && self->expression.outl) {
        *out = self->expression.outl;
    }

    if (!ast_istype(self->array, ast_value)) {
        asterror(ast_ctx(self), "array indexing this way is not supported");
        /* note this would actually be pointer indexing because the left side is
         * not an actual array but (hopefully) an indexable expression.
         * Once we get integer arithmetic, and GADDRESS/GSTORE/GLOAD instruction
         * support this path will be filled.
         */
        return false;
    }

    arr = (ast_value*)self->array;
    idx = (ast_value*)self->index;

    if (!ast_istype(self->index, ast_value) || !idx->isconst) {
        /* Time to use accessor functions */
        ast_expression_codegen *cgen;
        ir_value               *iridx, *funval;
        ir_instr               *call;

        if (lvalue) {
            asterror(ast_ctx(self), "(.2) array indexing here needs a compile-time constant");
            return false;
        }

        if (!arr->getter) {
            asterror(ast_ctx(self), "value has no getter, don't know how to index it");
            return false;
        }

        cgen = self->index->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->index), func, true, &iridx))
            return false;

        cgen = arr->getter->expression.codegen;
        if (!(*cgen)((ast_expression*)(arr->getter), func, true, &funval))
            return false;

        call = ir_block_create_call(func->curblock, ast_function_label(func, "fetch"), funval);
        if (!call)
            return false;
        ir_call_param(call, iridx);

        *out = ir_call_value(call);
        self->expression.outr = *out;
        return true;
    }

    if (idx->expression.vtype == TYPE_FLOAT)
        *out = arr->ir_values[(int)idx->constval.vfloat];
    else if (idx->expression.vtype == TYPE_INTEGER)
        *out = arr->ir_values[idx->constval.vint];
    else {
        asterror(ast_ctx(self), "array indexing here needs an integer constant");
        return false;
    }
    return true;
}

bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;

    ir_value *condval;
    ir_value *dummy;

    ir_block *cond = func->curblock;
    ir_block *ontrue;
    ir_block *onfalse;
    ir_block *ontrue_endblock = NULL;
    ir_block *onfalse_endblock = NULL;
    ir_block *merge;

    /* We don't output any value, thus also don't care about r/lvalue */
    (void)out;
    (void)lvalue;

    if (self->expression.outr) {
        asterror(ast_ctx(self), "internal error: ast_ifthen cannot be reused, it bears no result!");
        return false;
    }
    self->expression.outr = (ir_value*)1;

    /* generate the condition */
    func->curblock = cond;
    cgen = self->cond->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
        return false;

    /* on-true path */

    if (self->on_true) {
        /* create on-true block */
        ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
        if (!ontrue)
            return false;

        /* enter the block */
        func->curblock = ontrue;

        /* generate */
        cgen = self->on_true->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
            return false;

        /* we now need to work from the current endpoint */
        ontrue_endblock = func->curblock;
    } else
        ontrue = NULL;

    /* on-false path */
    if (self->on_false) {
        /* create on-false block */
        onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
        if (!onfalse)
            return false;

        /* enter the block */
        func->curblock = onfalse;

        /* generate */
        cgen = self->on_false->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
            return false;

        /* we now need to work from the current endpoint */
        onfalse_endblock = func->curblock;
    } else
        onfalse = NULL;

    /* Merge block were they all merge in to */
    merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
    if (!merge)
        return false;

    /* add jumps ot the merge block */
    if (ontrue && !ontrue_endblock->final && !ir_block_create_jump(ontrue_endblock, merge))
        return false;
    if (onfalse && !onfalse_endblock->final && !ir_block_create_jump(onfalse_endblock, merge))
        return false;

    /* we create the if here, that way all blocks are ordered :)
     */
    if (!ir_block_create_if(cond, condval,
                            (ontrue  ? ontrue  : merge),
                            (onfalse ? onfalse : merge)))
    {
        return false;
    }

    /* Now enter the merge block */
    func->curblock = merge;

    return true;
}

bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;

    ir_value *condval;
    ir_value *trueval, *falseval;
    ir_instr *phi;

    ir_block *cond = func->curblock;
    ir_block *ontrue;
    ir_block *onfalse;
    ir_block *merge;

    /* Ternary can never create an lvalue... */
    if (lvalue)
        return false;

    /* In theory it shouldn't be possible to pass through a node twice, but
     * in case we add any kind of optimization pass for the AST itself, it
     * may still happen, thus we remember a created ir_value and simply return one
     * if it already exists.
     */
    if (self->phi_out) {
        *out = self->phi_out;
        return true;
    }

    /* In the following, contraty to ast_ifthen, we assume both paths exist. */

    /* generate the condition */
    func->curblock = cond;
    cgen = self->cond->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
        return false;

    /* create on-true block */
    ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
    if (!ontrue)
        return false;
    else
    {
        /* enter the block */
        func->curblock = ontrue;

        /* generate */
        cgen = self->on_true->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
            return false;
    }

    /* create on-false block */
    onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
    if (!onfalse)
        return false;
    else
    {
        /* enter the block */
        func->curblock = onfalse;

        /* generate */
        cgen = self->on_false->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->on_false), func, false, &falseval))
            return false;
    }

    /* create merge block */
    merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
    if (!merge)
        return false;
    /* jump to merge block */
    if (!ir_block_create_jump(ontrue, merge))
        return false;
    if (!ir_block_create_jump(onfalse, merge))
        return false;

    /* create if instruction */
    if (!ir_block_create_if(cond, condval, ontrue, onfalse))
        return false;

    /* Now enter the merge block */
    func->curblock = merge;

    /* Here, now, we need a PHI node
     * but first some sanity checking...
     */
    if (trueval->vtype != falseval->vtype) {
        /* error("ternary with different types on the two sides"); */
        return false;
    }

    /* create PHI */
    phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
    if (!phi)
        return false;
    ir_phi_add(phi, ontrue,  trueval);
    ir_phi_add(phi, onfalse, falseval);

    self->phi_out = ir_phi_value(phi);
    *out = self->phi_out;

    return true;
}

bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;

    ir_value *dummy      = NULL;
    ir_value *precond    = NULL;
    ir_value *postcond   = NULL;

    /* Since we insert some jumps "late" so we have blocks
     * ordered "nicely", we need to keep track of the actual end-blocks
     * of expressions to add the jumps to.
     */
    ir_block *bbody      = NULL, *end_bbody      = NULL;
    ir_block *bprecond   = NULL, *end_bprecond   = NULL;
    ir_block *bpostcond  = NULL, *end_bpostcond  = NULL;
    ir_block *bincrement = NULL, *end_bincrement = NULL;
    ir_block *bout       = NULL, *bin            = NULL;

    /* let's at least move the outgoing block to the end */
    size_t    bout_id;

    /* 'break' and 'continue' need to be able to find the right blocks */
    ir_block *bcontinue     = NULL;
    ir_block *bbreak        = NULL;

    ir_block *old_bcontinue = NULL;
    ir_block *old_bbreak    = NULL;

    ir_block *tmpblock      = NULL;

    (void)lvalue;
    (void)out;

    if (self->expression.outr) {
        asterror(ast_ctx(self), "internal error: ast_loop cannot be reused, it bears no result!");
        return false;
    }
    self->expression.outr = (ir_value*)1;

    /* NOTE:
     * Should we ever need some kind of block ordering, better make this function
     * move blocks around than write a block ordering algorithm later... after all
     * the ast and ir should work together, not against each other.
     */

    /* initexpr doesn't get its own block, it's pointless, it could create more blocks
     * anyway if for example it contains a ternary.
     */
    if (self->initexpr)
    {
        cgen = self->initexpr->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
            return false;
    }

    /* Store the block from which we enter this chaos */
    bin = func->curblock;

    /* The pre-loop condition needs its own block since we
     * need to be able to jump to the start of that expression.
     */
    if (self->precond)
    {
        bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
        if (!bprecond)
            return false;

        /* the pre-loop-condition the least important place to 'continue' at */
        bcontinue = bprecond;

        /* enter */
        func->curblock = bprecond;

        /* generate */
        cgen = self->precond->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
            return false;

        end_bprecond = func->curblock;
    } else {
        bprecond = end_bprecond = NULL;
    }

    /* Now the next blocks won't be ordered nicely, but we need to
     * generate them this early for 'break' and 'continue'.
     */
    if (self->increment) {
        bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
        if (!bincrement)
            return false;
        bcontinue = bincrement; /* increment comes before the pre-loop-condition */
    } else {
        bincrement = end_bincrement = NULL;
    }

    if (self->postcond) {
        bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
        if (!bpostcond)
            return false;
        bcontinue = bpostcond; /* postcond comes before the increment */
    } else {
        bpostcond = end_bpostcond = NULL;
    }

    bout_id = vec_size(func->ir_func->blocks);
    bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
    if (!bout)
        return false;
    bbreak = bout;

    /* The loop body... */
    if (self->body)
    {
        bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
        if (!bbody)
            return false;

        /* enter */
        func->curblock = bbody;

        old_bbreak          = func->breakblock;
        old_bcontinue       = func->continueblock;
        func->breakblock    = bbreak;
        func->continueblock = bcontinue;

        /* generate */
        cgen = self->body->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
            return false;

        end_bbody = func->curblock;
        func->breakblock    = old_bbreak;
        func->continueblock = old_bcontinue;
    }

    /* post-loop-condition */
    if (self->postcond)
    {
        /* enter */
        func->curblock = bpostcond;

        /* generate */
        cgen = self->postcond->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
            return false;

        end_bpostcond = func->curblock;
    }

    /* The incrementor */
    if (self->increment)
    {
        /* enter */
        func->curblock = bincrement;

        /* generate */
        cgen = self->increment->expression.codegen;
        if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
            return false;

        end_bincrement = func->curblock;
    }

    /* In any case now, we continue from the outgoing block */
    func->curblock = bout;

    /* Now all blocks are in place */
    /* From 'bin' we jump to whatever comes first */
    if      (bprecond)   tmpblock = bprecond;
    else if (bbody)      tmpblock = bbody;
    else if (bpostcond)  tmpblock = bpostcond;
    else                 tmpblock = bout;
    if (!ir_block_create_jump(bin, tmpblock))
        return false;

    /* From precond */
    if (bprecond)
    {
        ir_block *ontrue, *onfalse;
        if      (bbody)      ontrue = bbody;
        else if (bincrement) ontrue = bincrement;
        else if (bpostcond)  ontrue = bpostcond;
        else                 ontrue = bprecond;
        onfalse = bout;
        if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
            return false;
    }

    /* from body */
    if (bbody)
    {
        if      (bincrement) tmpblock = bincrement;
        else if (bpostcond)  tmpblock = bpostcond;
        else if (bprecond)   tmpblock = bprecond;
        else                 tmpblock = bout;
        if (!end_bbody->final && !ir_block_create_jump(end_bbody, tmpblock))
            return false;
    }

    /* from increment */
    if (bincrement)
    {
        if      (bpostcond)  tmpblock = bpostcond;
        else if (bprecond)   tmpblock = bprecond;
        else if (bbody)      tmpblock = bbody;
        else                 tmpblock = bout;
        if (!ir_block_create_jump(end_bincrement, tmpblock))
            return false;
    }

    /* from postcond */
    if (bpostcond)
    {
        ir_block *ontrue, *onfalse;
        if      (bprecond)   ontrue = bprecond;
        else if (bbody)      ontrue = bbody;
        else if (bincrement) ontrue = bincrement;
        else                 ontrue = bpostcond;
        onfalse = bout;
        if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
            return false;
    }

    /* Move 'bout' to the end */
    vec_remove(func->ir_func->blocks, bout_id, 1);
    vec_push(func->ir_func->blocks, bout);

    return true;
}

bool ast_breakcont_codegen(ast_breakcont *self, ast_function *func, bool lvalue, ir_value **out)
{
    ir_block *target;

    if (lvalue) {
        asterror(ast_ctx(self), "break/continue expression is not an l-value");
        return false;
    }

    if (self->expression.outr) {
        asterror(ast_ctx(self), "internal error: ast_breakcont cannot be reused!");
        return false;
    }
    self->expression.outr = (ir_value*)1;

    if (self->is_continue)
        target = func->continueblock;
    else
        target = func->breakblock;

    if (!ir_block_create_jump(func->curblock, target))
        return false;
    return true;
}

bool ast_switch_codegen(ast_switch *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;

    ast_switch_case *def_case  = NULL;
    ir_block        *def_bfall = NULL;

    ir_value *dummy     = NULL;
    ir_value *irop      = NULL;
    ir_block *old_break = NULL;
    ir_block *bout      = NULL;
    ir_block *bfall     = NULL;
    size_t    bout_id;
    size_t    c;

    char      typestr[1024];
    uint16_t  cmpinstr;

    if (lvalue) {
        asterror(ast_ctx(self), "switch expression is not an l-value");
        return false;
    }

    if (self->expression.outr) {
        asterror(ast_ctx(self), "internal error: ast_switch cannot be reused!");
        return false;
    }
    self->expression.outr = (ir_value*)1;

    (void)lvalue;
    (void)out;

    cgen = self->operand->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->operand), func, false, &irop))
        return false;

    if (!vec_size(self->cases))
        return true;

    cmpinstr = type_eq_instr[irop->vtype];
    if (cmpinstr >= AINSTR_END) {
        ast_type_to_string(self->operand, typestr, sizeof(typestr));
        asterror(ast_ctx(self), "invalid type to perform a switch on: %s", typestr);
        return false;
    }

    bout_id = vec_size(func->ir_func->blocks);
    bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_switch"));
    if (!bout)
        return false;

    /* setup the break block */
    old_break        = func->breakblock;
    func->breakblock = bout;

    /* Now create all cases */
    for (c = 0; c < vec_size(self->cases); ++c) {
        ir_value *cond, *val;
        ir_block *bcase, *bnot;
        size_t bnot_id;

        ast_switch_case *swcase = &self->cases[c];

        if (swcase->value) {
            /* A regular case */
            /* generate the condition operand */
            cgen = swcase->value->expression.codegen;
            if (!(*cgen)((ast_expression*)(swcase->value), func, false, &val))
                return false;
            /* generate the condition */
            cond = ir_block_create_binop(func->curblock, ast_function_label(func, "switch_eq"), cmpinstr, irop, val);
            if (!cond)
                return false;

            bcase = ir_function_create_block(func->ir_func, ast_function_label(func, "case"));
            bnot_id = vec_size(func->ir_func->blocks);
            bnot = ir_function_create_block(func->ir_func, ast_function_label(func, "not_case"));
            if (!bcase || !bnot)
                return false;
            if (!ir_block_create_if(func->curblock, cond, bcase, bnot))
                return false;

            /* Make the previous case-end fall through */
            if (bfall && !bfall->final) {
                if (!ir_block_create_jump(bfall, bcase))
                    return false;
            }

            /* enter the case */
            func->curblock = bcase;
            cgen = swcase->code->expression.codegen;
            if (!(*cgen)((ast_expression*)swcase->code, func, false, &dummy))
                return false;

            /* remember this block to fall through from */
            bfall = func->curblock;

            /* enter the else and move it down */
            func->curblock = bnot;
            vec_remove(func->ir_func->blocks, bnot_id, 1);
            vec_push(func->ir_func->blocks, bnot);
        } else {
            /* The default case */
            /* Remember where to fall through from: */
            def_bfall = bfall;
            bfall     = NULL;
            /* remember which case it was */
            def_case  = swcase;
        }
    }

    /* If there was a default case, put it down here */
    if (def_case) {
        ir_block *bcase;

        /* No need to create an extra block */
        bcase = func->curblock;

        /* Insert the fallthrough jump */
        if (def_bfall && !def_bfall->final) {
            if (!ir_block_create_jump(def_bfall, bcase))
                return false;
        }

        /* Now generate the default code */
        cgen = def_case->code->expression.codegen;
        if (!(*cgen)((ast_expression*)def_case->code, func, false, &dummy))
            return false;
    }

    /* Jump from the last bnot to bout */
    if (!func->curblock->final && !ir_block_create_jump(func->curblock, bout))
        return false;
    /* enter the outgoing block */
    func->curblock = bout;

    /* restore the break block */
    func->breakblock = old_break;

    /* Move 'bout' to the end, it's nicer */
    vec_remove(func->ir_func->blocks, bout_id, 1);
    vec_push(func->ir_func->blocks, bout);

    return true;
}

bool ast_call_codegen(ast_call *self, ast_function *func, bool lvalue, ir_value **out)
{
    ast_expression_codegen *cgen;
    ir_value              **params;
    ir_instr               *callinstr;
    size_t i;

    ir_value *funval = NULL;

    /* return values are never lvalues */
    if (lvalue) {
        asterror(ast_ctx(self), "not an l-value (function call)");
        return false;
    }

    if (self->expression.outr) {
        *out = self->expression.outr;
        return true;
    }

    cgen = self->func->expression.codegen;
    if (!(*cgen)((ast_expression*)(self->func), func, false, &funval))
        return false;
    if (!funval)
        return false;

    params = NULL;

    /* parameters */
    for (i = 0; i < vec_size(self->params); ++i)
    {
        ir_value *param;
        ast_expression *expr = self->params[i];

        cgen = expr->expression.codegen;
        if (!(*cgen)(expr, func, false, &param))
            goto error;
        if (!param)
            goto error;
        vec_push(params, param);
    }

    callinstr = ir_block_create_call(func->curblock, ast_function_label(func, "call"), funval);
    if (!callinstr)
        goto error;

    for (i = 0; i < vec_size(params); ++i) {
        ir_call_param(callinstr, params[i]);
    }

    *out = ir_call_value(callinstr);
    self->expression.outr = *out;

    vec_free(params);
    return true;
error:
    vec_free(params);
    return false;
}