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mirror of git://projects.qi-hardware.com/eda-tools.git synced 2024-11-22 20:14:04 +02:00

eeshow/kicad/sexpr.c, sexpr.h: simple parser for S-expressions

This commit is contained in:
Werner Almesberger 2016-08-22 01:10:55 -03:00
parent 328ddd9ca7
commit 12f66ec47e
3 changed files with 383 additions and 1 deletions

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@ -15,7 +15,7 @@ SHELL = /bin/bash
NAME = eeshow NAME = eeshow
OBJS = main.o version.o \ OBJS = main.o version.o \
kicad/sch-parse.o kicad/sch-render.o kicad/lib-parse.o \ kicad/sch-parse.o kicad/sch-render.o kicad/lib-parse.o \
kicad/lib-render.o kicad/dwg.o kicad/delta.o \ kicad/lib-render.o kicad/dwg.o kicad/delta.o kicad/sexpr.o \
gui/gui.o gui/over.o gui/style.o gui/aoi.o gui/fmt-pango.o gui/input.o \ gui/gui.o gui/over.o gui/style.o gui/aoi.o gui/fmt-pango.o gui/input.o \
gui/progress.o gui/glabel.o gui/sheet.o gui/history.o gui/render.o \ gui/progress.o gui/glabel.o gui/sheet.o gui/history.o gui/render.o \
gui/help.o gui/icons.o \ gui/help.o gui/icons.o \

335
eeshow/kicad/sexpr.c Normal file
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/*
* kicad/sexpr.c - S-expression parser
*
* Written 2016 by Werner Almesberger
* Copyright 2016 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 <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "misc/util.h"
#include "misc/diag.h"
#include "kicad/sexpr.h"
struct stack {
struct expr **next;
struct stack *prev;
};
struct sexpr_ctx {
enum sexpr_state {
idle,
token,
string,
escape,
failed
} state;
struct expr *e; /* expression */
const char *p; /* beginning of string */
struct stack *sp;
struct stack stack;
};
/* ----- Parser ------------------------------------------------------------ */
static void new_expr(struct sexpr_ctx *ctx)
{
struct stack *st = alloc_type(struct stack);
struct expr *e = alloc_type(struct expr);
e->s = NULL;
e->e = NULL;
e->next = NULL;
*ctx->sp->next = e;
ctx->sp->next = &e->next;
st->prev = ctx->sp;
st->next = &e->e;
ctx->sp = st;
}
static void add_string(struct sexpr_ctx *ctx, const char *end)
{
struct expr *e;
unsigned old;
unsigned new = end - ctx->p;
e = *ctx->sp->next;
if (e) {
old = strlen(e->s);
} else {
e = alloc_type(struct expr);
e->s = NULL;
e->e = NULL;
e->next = NULL;
*ctx->sp->next = e;
old = 0;
}
if (!new)
return;
e->s = realloc(e->s, old + new + 1);
if (!e->s)
diag_pfatal("realloc");
memcpy(e->s + old, ctx->p, new);
e->s[old + new] = 0;
}
static void end_string(struct sexpr_ctx *ctx, const char *end)
{
struct expr *e;
char *s, *t;
add_string(ctx, end);
e = *ctx->sp->next;
ctx->sp->next = &e->next;
for (s = t = e->s; *s; s++) {
if (*s == '\\')
switch (*++s) {
case 'n':
*t++ = '\n';
continue;
case 't':
*t++ = '\t';
continue;
case 0:
abort();
default:
break;
}
*t++ = *s;
}
*t = 0;
}
bool sexpr_parse(struct sexpr_ctx *ctx, const char *s)
{
ctx->p = s;
while (*s) {
switch (ctx->state) {
case idle:
switch (*s) {
case ' ':
case '\t':
case '\r':
case '\n':
break;
case '(':
new_expr(ctx);
break;
case ')':
if (!ctx->sp->prev) {
ctx->state = failed;
error("too many\n )");
break;
}
ctx->sp = ctx->sp->prev;
break;
case '"':
ctx->state = string;
ctx->p = s + 1;
break;
default:
ctx->p = s;
ctx->state = token;
break;
}
break;
case token:
switch (*s) {
case ' ':
case '\t':
case '\r':
case '\n':
ctx->state = idle;
end_string(ctx, s);
break;
case '(':
case ')':
case '"':
ctx->state = idle;
end_string(ctx, s);
continue;
default:
break;
}
break;
case string:
switch (*s) {
case '\r':
case '\n':
ctx->state = failed;
error("newline in string\n");
break;
case '"':
ctx->state = idle;
add_string(ctx, s);
break;
case '\\':
ctx->state = escape;
break;
default:
break;
}
break;
case escape:
switch (*s) {
case '\r':
case '\n':
ctx->state = failed;
error("newline in string\n");
break;
default:
ctx->state = string;
break;
}
break;
case failed:
return 0;
default:
abort();
}
s++;
}
switch (ctx->state) {
case token:
case string:
case escape:
add_string(ctx, s);
break;
default:
break;
}
return 1;
}
/* ----- Dumping ----------------------------------------------------------- */
static void do_dump_expr(const struct expr *e, unsigned depth)
{
bool need_nl = 0;
if (depth)
printf("%*s(", (depth - 1) * 2, "");
while (e) {
if (e->s) {
if (need_nl) {
printf("\n%*s", depth * 2, "");
need_nl = 0;
}
printf("\"%s\" ", e->s); /* @@@ escaping */
}
if (e->e) {
putchar('\n');
do_dump_expr(e->e, depth + 1);
need_nl = 1;
}
e = e->next;
}
if (depth)
putchar(')');
}
void dump_expr(const struct expr *e)
{
do_dump_expr(e, 0);
putchar('\n');
}
/* ----- Cleanup ----------------------------------------------------------- */
static void free_stack(struct sexpr_ctx *ctx)
{
struct stack *prev;
while (ctx->sp != &ctx->stack) {
prev = ctx->sp->prev;
free(ctx->sp);
ctx->sp = prev;
}
}
void free_expr(struct expr *e)
{
struct expr *next;
while (e) {
next = e->next;
if (e->s)
free(e->s);
else if (e->e)
free_expr(e->e);
free(e);
e = next;
}
}
/* ----- Parser creation --------------------------------------------------- */
struct sexpr_ctx *sexpr_new(void)
{
struct sexpr_ctx *ctx;
ctx = alloc_type(struct sexpr_ctx);
ctx->state = idle;
ctx->e = NULL;
ctx->p = NULL;
ctx->sp = &ctx->stack;
ctx->stack.next = &ctx->e;
ctx->stack.prev = NULL;
return ctx;
}
/* ----- Termination ------------------------------------------------------- */
bool sexpr_finish(struct sexpr_ctx *ctx, struct expr **res)
{
if (ctx->sp != &ctx->stack) {
error("not enough )\n");
ctx->state = failed;
free_stack(ctx);
}
if (ctx->state != idle && ctx->state != failed)
error("invalid end state %d\n", ctx->state);
if (ctx->state == idle) {
if (res)
*res = ctx->e;
else
free_expr(ctx->e);
free(ctx);
return 1;
}
free_expr(ctx->e);
free(ctx);
return 0;
}

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eeshow/kicad/sexpr.h Normal file
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/*
* kicad/sexpr.h - S-expression parser
*
* Written 2016 by Werner Almesberger
* Copyright 2016 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.
*/
#ifndef KICAD_SEXPR_H
#define KICAD_SEXPR_H
#include <stdbool.h>
/*
* Expression type:
*
* s e Meaning
* ------------ -------- ----------
* NULL NULL "" or ()
* non-NULL NULL foo or "foo"
* NULL non-NULL (...)
* non-NULL non-NULL trouble
*/
struct expr {
char *s; /* string or NULL */
struct expr *e; /* sub-sexpr or NULL*/
struct expr *next;
};
struct sexpr_ctx;
void dump_expr(const struct expr *e);
void free_expr(struct expr *e);
struct sexpr_ctx *sexpr_new(void);
bool sexpr_parse(struct sexpr_ctx *ctx, const char *s);
bool sexpr_finish(struct sexpr_ctx *ctx, struct expr **res);
#endif /* !KICAD_SEXPR_H */