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mirror of git://projects.qi-hardware.com/fped.git synced 2024-11-04 23:55:54 +02:00
fped/expr.c
werner 766efce919 - tables no longer try to fill the available space in the variables area
- added string-valued expressions (on-going)
- loops, tables, and rows can now be deleted/undeleted (still need columns)



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5397 99fdad57-331a-0410-800a-d7fa5415bdb3
2009-08-06 21:57:18 +00:00

446 lines
8.0 KiB
C

/*
* expr.c - Expressions and values
*
* Written 2009 by Werner Almesberger
* Copyright 2009 by Werner Almesberger
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <stdlib.h>
#include <math.h>
#include "util.h"
#include "error.h"
#include "obj.h"
#include "unparse.h"
#include "expr.h"
struct num undef = { .type = nt_none };
/* ----- error reporting --------------------------------------------------- */
void fail_expr(const struct expr *expr)
{
char *s;
s = unparse(expr);
fail("in \"%s\" at line %d", s, expr->lineno);
free(s);
}
/* ----- unit conversion --------------------------------------------------- */
const char *str_unit(struct num n)
{
if (n.exponent == 0)
return "";
if (n.type == nt_mm) {
switch (n.exponent) {
case -2:
return "mm^-2";
case -1:
return "mm^-1";
case 1:
return "mm";
case 2:
return "mm^2";
default:
abort();
}
}
if (n.type == nt_mil) {
switch (n.exponent) {
case -2:
return "mil^(-2)";
case -1:
return "mil^(-1)";
case 1:
return "mil";
case 2:
return "mil^2";
default:
abort();
}
}
abort();
}
int to_unit(struct num *n)
{
if (!is_distance(*n)) {
fail("%s^%d is not a distance",
n->type == nt_mm ? "mm" : n->type == nt_mil ? "mil" : "?",
n->exponent);
return 0;
}
switch (n->type) {
case nt_mil:
n->n = mil_to_units(n->n);
break;
case nt_mm:
n->n = mm_to_units(n->n);
break;
default:
abort();
}
return 1;
}
/* ----- primary expressions ----------------------------------------------- */
struct num op_string(const struct expr *self, const struct frame *frame)
{
fail("cannot evaluate string");
return undef;
}
struct num op_num(const struct expr *self, const struct frame *frame)
{
return self->u.num;
}
struct num eval_var(const struct frame *frame, const char *name)
{
const struct table *table;
const struct loop *loop;
const struct value *value;
struct var *var;
struct num res;
for (table = frame->tables; table; table = table->next) {
value = table->curr_row->values;
for (var = table->vars; var; var = var->next) {
if (var->name == name) {
if (var->visited) {
fail("recursive evaluation through "
"\"%s\"", name);
return undef;
}
var->visited = 1;
res = eval_num(value->expr, frame);
var->visited = 0;
return res;
}
value = value->next;
}
}
for (loop = frame->loops; loop; loop = loop->next)
if (loop->var.name == name) {
if (!loop->initialized) {
fail("uninitialized loop \"%s\"", name);
return undef;
}
return make_num(loop->curr_value);
}
if (frame->curr_parent)
return eval_var(frame->curr_parent, name);
return undef;
}
struct num op_var(const struct expr *self, const struct frame *frame)
{
struct num res;
res = eval_var(frame, self->u.var);
if (is_undef(res))
fail("undefined variable \"%s\"", self->u.var);
return res;
}
/* ----- arithmetic -------------------------------------------------------- */
static struct num compatible_sum(struct num *a, struct num *b)
{
struct num res;
if (a->type != b->type) {
if (a->type == nt_mil) {
a->type = nt_mm;
a->n = mil_to_mm(a->n, a->exponent);
}
if (b->type == nt_mil) {
b->type = nt_mm;
b->n = mil_to_mm(b->n, a->exponent);
}
}
if (a->exponent != b->exponent) {
fail("incompatible exponents (%d, %d)",
a->exponent, b->exponent);
return undef;
}
res.type = a->type;
res.exponent = a->exponent;
res.n = 0; /* keep gcc happy */
return res;
}
static struct num compatible_mult(struct num *a, struct num *b,
int exponent)
{
struct num res;
if (a->type != b->type) {
if (a->type == nt_mil) {
a->type = nt_mm;
a->n = mil_to_mm(a->n, a->exponent);
}
if (b->type == nt_mil) {
b->type = nt_mm;
b->n = mil_to_mm(b->n, b->exponent);
}
}
res.type = a->type;
res.exponent = exponent;
res.n = 0; /* keep gcc happy */
return res;
}
struct num op_minus(const struct expr *self, const struct frame *frame)
{
struct num res;
res = eval_num(self->u.op.a, frame);
if (!is_undef(res))
res.n = -res.n;
return res;
}
#define BINARY \
struct num a, b, res; \
\
a = eval_num(self->u.op.a, frame); \
if (is_undef(a)) \
return undef; \
b = eval_num(self->u.op.b, frame); \
if (is_undef(b)) \
return undef;
struct num op_add(const struct expr *self, const struct frame *frame)
{
BINARY;
res = compatible_sum(&a, &b);
if (is_undef(res))
return undef;
res.n = a.n+b.n;
return res;
}
struct num op_sub(const struct expr *self, const struct frame *frame)
{
BINARY;
res = compatible_sum(&a, &b);
if (is_undef(res))
return undef;
res.n = a.n-b.n;
return res;
}
struct num op_mult(const struct expr *self, const struct frame *frame)
{
BINARY;
res = compatible_mult(&a, &b, a.exponent+b.exponent);
res.n = a.n*b.n;
return res;
}
struct num op_div(const struct expr *self, const struct frame *frame)
{
BINARY;
if (!b.n) {
fail("Division by zero");
return undef;
}
res = compatible_mult(&a, &b, a.exponent-b.exponent);
res.n = a.n/b.n;
return res;
}
/* ----- expression construction ------------------------------------------- */
struct expr *new_op(op_type op)
{
struct expr *expr;
expr = alloc_type(struct expr);
expr->op = op;
expr->lineno = lineno;
return expr;
}
struct expr *binary_op(op_type op, struct expr *a, struct expr *b)
{
struct expr *expr;
expr = new_op(op);
expr->u.op.a = a;
expr->u.op.b = b;
return expr;
}
char *eval_str(const struct frame *frame, const struct expr *expr)
{
abort();
}
struct num eval_num(const struct expr *expr, const struct frame *frame)
{
return expr->op(expr, frame);
}
/* ----- string expansion -------------------------------------------------- */
char *expand(const char *name, const struct frame *frame)
{
int len = strlen(name);
char *buf = alloc_size(len+1);
char num_buf[100]; /* enough :-) */
const char *s, *s0;
char *var;
const char *var_unique;
struct num value;
int i, value_len;
i = 0;
for (s = name; *s; s++) {
if (*s != '$') {
buf[i++] = *s;
continue;
}
s0 = ++s;
if (*s != '{') {
while (is_id_char(*s, s == s0))
s++;
if (s == s0)
goto invalid;
var = strnalloc(s0, s-s0);
len -= s-s0+1;
s--;
} else {
s++;
while (*s != '}') {
if (!*s) {
fail("unfinished \"${...}\"");
goto fail;
}
if (!is_id_char(*s, s == s0+1))
goto invalid;
s++;
}
var = strnalloc(s0+1, s-s0-1);
len -= s-s0+2;
}
if (!frame)
continue;
var_unique = unique(var);
free(var);
value = eval_var(frame, var_unique);
if (is_undef(value)) {
fail("undefined variable \"%s\"", var_unique);
goto fail;
}
value_len = snprintf(num_buf, sizeof(num_buf), "%lg%s",
value.n, str_unit(value));
len += value_len;
buf = realloc(buf, len+1);
if (!buf)
abort();
strcpy(buf+i, num_buf);
i += value_len;
}
buf[i] = 0;
return buf;
invalid:
fail("invalid character in variable name");
fail:
free(buf);
return NULL;
}
/* ----- make a number -----------------------------------------------------*/
struct expr *new_num(struct num num)
{
struct expr *expr;
expr = new_op(op_num);
expr->u.num = num;
return expr;
}
/* ----- expression-only parser -------------------------------------------- */
void scan_expr(const char *s);
int yyparse(void);
struct expr *expr_result;
struct expr *parse_expr(const char *s)
{
scan_expr(s);
return yyparse() ? NULL : expr_result;
}
static void vacate_op(struct expr *expr)
{
if (expr->op == &op_num || expr->op == &op_var)
return;
if (expr->op == &op_minus) {
free_expr(expr->u.op.a);
return;
}
if (expr->op == &op_add || expr->op == &op_sub ||
expr->op == &op_mult || expr->op == &op_div) {
free_expr(expr->u.op.a);
free_expr(expr->u.op.b);
return;
}
abort();
}
void free_expr(struct expr *expr)
{
vacate_op(expr);
free(expr);
}