TMX parser rewrite number one.

11 files changed, 731 insertions, 19 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index ac515cc..2ddbe94 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -4,6 +4,7 @@ src_SOURCES = \
               src/main.c \
               src/init.c \
               src/logging.c \
+              src/xml.c \
               src/base64.c \
               src/compression.c \
               src/tmx.c \
diff --git a/src/map.h b/src/map.h
deleted file mode 100644
index 925bdd2..0000000
--- a/src/map.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#ifndef MAP_H
-#define MAP_H
-
-#include <SDL_stdinc.h>
-#include "tileset.h"
-#include "layer.h"
-
-struct map {
-	int width;
-	int height;
-	int tilewidth;
-	int tileheight;
-	struct tileset *tilesets;
-	struct layer *layers;
-	Uint8 *collision;
-};
-
-#endif
diff --git a/src/resources/Makefile.am b/src/resources/Makefile.am
index 71ddc4b..1829942 100644
--- a/src/resources/Makefile.am
+++ b/src/resources/Makefile.am
@@ -1,3 +1,5 @@
 src_resources_SOURCES = \
                         src/resources/resource.c \
-                        src/resources/image.c
+                        src/resources/image.c \
+                        src/resources/tileset.c \
+                        src/resources/map.c
diff --git a/src/resources/image.h b/src/resources/image.h
index 92ef040..b79f0ce 100644
--- a/src/resources/image.h
+++ b/src/resources/image.h
@@ -1,6 +1,7 @@
 #ifndef IMAGE_H
 #define IMAGE_H
 
+#include <SDL.h>
 #include "resource.h"
 
 struct image {
diff --git a/src/resources/layer.h b/src/resources/layer.h
new file mode 100644
index 0000000..82504de
--- /dev/null
+++ b/src/resources/layer.h
@@ -0,0 +1,14 @@
+#ifndef RESOURCE_LAYER_H
+#define RESOURCE_LAYER_H
+
+#include "resource.h"
+
+struct layer {
+	struct resource res;
+	char *name;
+	char *encoding;
+	char *compression;
+	struct layer *next;
+};
+
+#endif
diff --git a/src/resources/map.c b/src/resources/map.c
new file mode 100644
index 0000000..b703629
--- /dev/null
+++ b/src/resources/map.c
@@ -0,0 +1,423 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <expat.h>
+#include "map.h"
+#include "resource.h"
+#include "tileset.h"
+#include "../xml.h"
+#include "../logging.h"
+
+struct tmx {
+	XML_Parser p;
+	struct map *map;
+	char *layer_data;
+};
+
+struct resource_table map_res;
+
+static void XMLCALL xml_map_start(void *data, const char *el,
+		const char **attr);
+static void XMLCALL xml_map_end(void *data, const char *el);
+static void XMLCALL xml_mapelem_start(void *data, const char *el,
+		const char **attr);
+static void XMLCALL xml_mapelem_end(void *data, const char *el);
+static void XMLCALL xml_image_start(void *data, const char *el,
+		const char **attr);
+static void XMLCALL xml_image_end(void *data, const char *el);
+static void XMLCALL xml_data_start(void *data, const char *el,
+		const char **attr);
+static void XMLCALL xml_data_data(void *data, const char *s, int len);
+static void XMLCALL xml_data_end(void *data, const char *el);
+static void XMLCALL xml_object_start(void *data, const char *el,
+		const char **attr);
+static void XMLCALL xml_object_end(void *data, const char *el);
+
+void map_add_layer(struct map *m, struct layer *l);
+void map_add_tileset(struct map *m, struct tileset *t);
+
+static void XMLCALL
+xml_map_start(void *data, const char *el, const char **attr)
+{
+	struct tmx *tmx;
+
+	debug("<%s> (type \"map\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "map")) {
+		if (tmx->map != NULL) {
+			warn("Found multiple maps in TMX file");
+			XML_StopParser(tmx->p, XML_FALSE);
+		}
+		tmx->map = malloc(sizeof(*tmx->map));
+		if (tmx->map == NULL) {
+			warn("Failed to allocate map");
+			XML_StopParser(tmx->p, XML_FALSE);
+		}
+		memset(tmx->map, 0, sizeof(*tmx->map));
+		xml_get_int_attr(tmx->p, attr, "width",
+				&tmx->map->width, 1);
+		xml_get_int_attr(tmx->p, attr, "width",
+				&tmx->map->width, 1);
+		xml_get_int_attr(tmx->p, attr, "tilewidth",
+				&tmx->map->tilewidth, 1);
+		xml_get_int_attr(tmx->p, attr, "tileheight",
+				&tmx->map->tileheight, 1);
+		XML_SetStartElementHandler(tmx->p, xml_mapelem_start);
+		XML_SetEndElementHandler(tmx->p, xml_map_end);
+	} else {
+		xml_unexpected_start_tag(tmx->p, el,
+				"map");
+	}
+}
+
+static void XMLCALL
+xml_map_end(void *data, const char *el)
+{
+	struct tmx *tmx;
+
+	debug("</%s> (type \"map\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "map")) {
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, NULL);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"map");
+	}
+}
+
+static void XMLCALL
+xml_mapelem_start(void *data, const char *el, const char **attr)
+{
+	struct tmx *tmx;
+	char *source;
+	struct tileset *ts;
+	struct layer *ly;
+
+	debug("<%s> (type \"mapelem\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "tileset")) {
+		source = NULL;
+		xml_get_string_attr(tmx->p, attr, "source",
+				&source, 0);
+		if (source != NULL) {
+			ts = tileset_get(source);
+			free(source);
+			XML_SetStartElementHandler(tmx->p, NULL);
+			XML_SetEndElementHandler(tmx->p, xml_tileset_end);
+		} else {
+			ts = resource_alloc("", sizeof(*ts));
+			xml_get_int_attr(tmx->p, attr, "tilewidth",
+					&ts->tilewidth, 1);
+			xml_get_int_attr(tmx->p, attr, "tileheight",
+					&ts->tileheight, 1);
+			/* TODO: Change xml_image_start to xml_tselem_start.
+			 * A <tileset> can contain:
+			 *   * Zero or one <properties>,
+			 *   * Zero or one <image>s, and
+			 *   * Zero or more <tile>s. */
+			XML_SetStartElementHandler(tmx->p, xml_image_start);
+			XML_SetEndElementHandler(tmx->p, xml_tileset_end);
+		}
+		xml_get_int_attr(tmx->p, attr, "firstgid",
+				&ts->firstgid, 1);
+		xml_get_string_attr(tmx->p, attr, "name",
+				&ts->name, 1);
+		map_add_tileset(tmx->map, ts);
+	} else if (xml_check_tag(el, "layer")) {
+		ly = resource_alloc("", sizeof(*ly));
+		xml_get_string_attr(tmx->p, attr, "name",
+				&ly->name, 1);
+		map_add_layer(tmx->map, ly);
+		XML_SetStartElementHandler(tmx->p, xml_data_start);
+		XML_SetEndElementHandler(tmx->p, xml_mapelem_end);
+	} else if (xml_check_tag(el, "objectgroup")) {
+		XML_SetStartElementHandler(tmx->p, xml_object_start);
+		XML_SetEndElementHandler(tmx->p, xml_mapelem_end);
+	} else {
+		xml_unexpected_start_tag(tmx->p, el,
+				"tileset, layer, or objectgroup");
+	}
+}
+
+static void XMLCALL
+xml_mapelem_end(void *data, const char *el)
+{
+	struct tmx *tmx;
+
+	debug("</%s> (type \"mapelem\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "tileset")) {
+		XML_SetStartElementHandler(tmx->p, xml_mapelem_start);
+		XML_SetEndElementHandler(tmx->p, xml_map_end);
+	} else if (xml_check_tag(el, "layer")) {
+		XML_SetStartElementHandler(tmx->p, xml_mapelem_start);
+		XML_SetEndElementHandler(tmx->p, xml_map_end);
+	} else if (xml_check_tag(el, "objectgroup")) {
+		XML_SetStartElementHandler(tmx->p, xml_mapelem_start);
+		XML_SetEndElementHandler(tmx->p, xml_map_end);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"tileset, layer, or objectgroup");
+	}
+}
+
+static void XMLCALL
+xml_image_start(void *data, const char *el, const char **attr)
+{
+	struct tmx *tmx;
+	struct tileset *ts;
+	char *source;
+
+	debug("<%s> (type \"image\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "image")) {
+		ts = tmx->map->tilesets_tail;
+		xml_get_string_attr(tmx->p, attr, "source",
+				&source, 1);
+		ts->image = img_png_get(source);
+		free(source);
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, xml_image_end);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"image");
+	}
+}
+
+static void XMLCALL
+xml_image_end(void *data, const char *el)
+{
+	struct tmx *tmx;
+
+	tmx = (struct tmx *) data;
+
+	debug("</%s> (type \"image\")", el);
+
+	if (xml_check_tag(el, "image")) {
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, xml_mapelem_end);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"image");
+	}
+}
+
+static void XMLCALL
+xml_data_start(void *data, const char *el, const char **attr)
+{
+	struct tmx *tmx;
+	struct layer *ly;
+
+	debug("<%s> (type \"data\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "data")) {
+		ly = tmx->map->layers_tail;
+		xml_get_string_attr(tmx->p, attr, "encoding",
+				&ly->encoding, 0);
+		xml_get_string_attr(tmx->p, attr, "compression",
+				&ly->compression, 0);
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, xml_data_end);
+		XML_SetCharacterDataHandler(tmx->p, xml_data_data);
+	} else {
+		xml_unexpected_start_tag(tmx->p, el,
+				"data");
+	}
+}
+
+static void XMLCALL
+xml_data_data(void *data, const char *s, int len)
+{
+	struct tmx *tmx;
+	char *s_z;
+	char *s_z_trimmed, *s_z_trimmed_end;
+
+	debug("...LAYER DATA...");
+
+	tmx = (struct tmx *) data;
+
+	s_z = s_z_trimmed = strndup(s, len);
+
+	while(isspace(*s_z_trimmed)) {
+		++s_z_trimmed;
+		--len;
+	}
+	if (*s_z_trimmed == '\0') {
+		return;
+	}
+	s_z_trimmed_end = s_z_trimmed + len - 1;
+	while (s_z_trimmed_end > s_z_trimmed && isspace(*s_z_trimmed_end)) {
+		--s_z_trimmed_end;
+	}
+	*(s_z_trimmed_end + 1) = '\0';
+
+	tmx->layer_data = strdup(s_z_trimmed);
+
+	free(s_z);
+}
+
+static void XMLCALL
+xml_data_end(void *data, const char *el)
+{
+	struct tmx *tmx;
+
+	debug("</%s> (type \"data\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "data")) {
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, xml_mapelem_end);
+		XML_SetCharacterDataHandler(tmx->p, NULL);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"data");
+	}
+}
+
+static void XMLCALL
+xml_object_start(void *data, const char *el,
+		const char **attr)
+{
+	struct tmx *tmx;
+	char *type;
+
+	debug("<%s> (type \"object\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "object")) {
+		/* TODO: Handle objects. */
+		xml_get_string_attr(tmx->p, attr, "type",
+				&type, 1);
+		if (strcmp(type, "exit") == 0) {
+		} else if (strcmp(type, "exit") == 0) {
+		}
+		XML_SetStartElementHandler(tmx->p, NULL);
+		XML_SetEndElementHandler(tmx->p, xml_object_end);
+	} else {
+		xml_unexpected_start_tag(tmx->p, el,
+				"object");
+	}
+}
+
+static void XMLCALL
+xml_object_end(void *data, const char *el)
+{
+	struct tmx *tmx;
+
+	debug("</%s> (type \"object\")", el);
+
+	tmx = (struct tmx *) data;
+
+	if (xml_check_tag(el, "object")) {
+		XML_SetStartElementHandler(tmx->p, xml_object_start);
+		XML_SetEndElementHandler(tmx->p, xml_mapelem_end);
+	} else {
+		xml_unexpected_end_tag(tmx->p, el,
+				"object");
+	}
+}
+
+struct map *
+map_get(const char *path)
+{
+	struct tmx tmx;
+	FILE *tmx_fp;
+	void *tmx_buf;
+	size_t len;
+	enum XML_Status status;
+
+	memset(&tmx, 0, sizeof(tmx));
+
+	tmx.map = (struct map *) resource_get(&map_res, path);
+	if (tmx.map != NULL) {
+		resource_use((struct resource *) tmx.map);
+		return tmx.map;
+	}
+
+	tmx.map = resource_alloc(path, sizeof(*tmx.map));
+
+	tmx.p = XML_ParserCreate(NULL);
+	if (tmx.p == NULL) {
+		warn("Failed to create TMX parser");
+		return NULL;
+	}
+
+	XML_SetStartElementHandler(tmx.p, xml_map_start);
+	XML_SetEndElementHandler(tmx.p, NULL);
+	XML_SetCharacterDataHandler(tmx.p, NULL);
+
+	XML_SetUserData(tmx.p, &tmx);
+
+	tmx_fp = fopen(path, "rb");
+	if (tmx_fp == NULL) {
+		warn("Failed to open TMX file");
+		XML_ParserFree(tmx.p);
+		return NULL;
+	}
+
+	tmx_buf = XML_GetBuffer(tmx.p, 8192);
+	if (tmx_buf == NULL) {
+		warn("Failed to create TMX parse buffer");
+		XML_ParserFree(tmx.p);
+		fclose(tmx_fp);
+		return NULL;
+	}
+
+	while (!feof(tmx_fp)) {
+		len = fread(tmx_buf, 1, 8192, tmx_fp);
+		status = XML_ParseBuffer(tmx.p, len, feof(tmx_fp));
+		if (status == XML_STATUS_OK) {
+			continue;
+		}
+		warn("Failed to parse TMX file (%s)",
+				XML_ErrorString(XML_GetErrorCode(tmx.p)));
+		XML_ParserFree(tmx.p);
+		fclose(tmx_fp);
+		return NULL;
+	}
+
+	XML_ParserFree(tmx.p);
+	fclose(tmx_fp);
+
+	resource_use((struct resource *) tmx.map);
+	resource_add(&map_res, path, (struct resource *) tmx.map);
+
+	return tmx.map;
+}
+
+void
+map_add_layer(struct map *m, struct layer *l)
+{
+	if (m->layers_head == NULL) {
+		m->layers_head = l;
+	} else {
+		m->layers_tail->next = l;
+	}
+	m->layers_tail = l;
+}
+
+void
+map_add_tileset(struct map *m, struct tileset *t)
+{
+	if (m->tilesets_head == NULL) {
+		m->tilesets_head = t;
+	} else {
+		m->tilesets_tail->next = t;
+	}
+	m->tilesets_tail = t;
+}
diff --git a/src/resources/map.h b/src/resources/map.h
new file mode 100644
index 0000000..04fcf27
--- /dev/null
+++ b/src/resources/map.h
@@ -0,0 +1,27 @@
+#ifndef RESOURCE_MAP_H
+#define RESOURCE_MAP_H
+
+#include <SDL_stdinc.h>
+#include "resource.h"
+#include "tileset.h"
+#include "layer.h"
+
+struct map {
+	struct resource res;
+	int width;
+	int height;
+	int tilewidth;
+	int tileheight;
+	struct tileset *tilesets_head;
+	struct tileset *tilesets_tail;
+	struct layer *layers_head;
+	struct layer *layers_tail;
+	Uint8 *collision;
+};
+
+struct map *map_get(const char *path);
+void map_free(struct map *map);
+void map_add_layer(struct map *m, struct layer *l);
+void map_add_tileset(struct map *m, struct tileset *t);
+
+#endif
diff --git a/src/resources/tileset.c b/src/resources/tileset.c
new file mode 100644
index 0000000..e15224a
--- /dev/null
+++ b/src/resources/tileset.c
@@ -0,0 +1,161 @@
+#include <expat.h>
+#include "tileset.h"
+#include "../xml.h"
+#include "../logging.h"
+
+/*
+ * Problem:
+ *     xml_tselem_start(), xml_tileset_end(), etc. may be called with one of two
+ *     types of user data.
+ * Possible solution:
+ *  1. Create a base (struct xml_doc) in src/xml.h:
+ *         struct xml_doc {
+ *             enum {
+ *                 XML_DOC_TMX,
+ *                 XML_DOC_TSX
+ *             } type;
+ *             XML_Parser p;
+ *         };
+ *  2. Make (struct tmx) and (struct tmx) "extend" it, e.g.:
+ *         struct tsx {
+ *             struct xml_doc doc;
+ *             struct tileset *ts;
+ *         };
+ *  3. Make xml_tselem_start(), xml_tileset_end(), etc. check the doc.type
+ *     member of the user data and find the (struct tileset *) accordingly.
+ * Wait, what?!
+ * Alternative solution:
+ *  1. Declare (struct tmx) in src/resources/map.h.
+ *  2. Add to (struct tsx) the following member:
+ *         struct tmx *parent_tmx;
+ *  3. In xml_mapelem_start() (src/resources/map.c):
+ *      1. Allocate a (struct tsx).
+ *      2. Set the parent_tmx member of the (struct tsx) to tmx.
+ *      3. Set the ts member of the (struct tsx) to ts.
+ *      4. Set the (struct tsx) as the user data.
+ *  4. In xml_tileset_end() (src/resources/tileset.c), add the following code:
+ *         if (tsx->parent_tmx != NULL) {
+ *             XML_SetUserData(tsx->p, tsx->parent_tmx);
+ *             free(tsx);
+ *             XML_SetStartElementHandler(tmx->p, xml_mapelem_start);
+ *             XML_SetEndElementHandler(tmx->p, xml_map_end);
+ *         }
+ * Alternative alternative solution:
+ *     Something that doesn't suck.
+ */
+struct tsx {
+	XML_Parser p;
+	struct tileset *ts;
+};
+
+struct resource_table ts_res;
+
+void XMLCALL
+xml_tileset_start(void *data, const char *el, const char **attr)
+{
+	struct tsx *tsx;
+
+	debug("<%s> (type \"tileset\")", el);
+
+	tsx = (struct tsx *) data;
+
+	if (xml_check_tag(el, "tileset")) {
+		xml_get_string_attr(tsx->p, attr, "name",
+				&tsx->ts->name, 1);
+		xml_get_int_attr(tsx->p, attr, "tilewidth",
+				&tsx->ts->tilewidth, 1);
+		xml_get_int_attr(tsx->p, attr, "tileheight",
+				&tsx->ts->tileheight, 1);
+/*		XML_SetStartElementHandler(tsx->p, xml_tselem_start);*/
+		XML_SetEndElementHandler(tsx->p, xml_tileset_end);
+	} else {
+		xml_unexpected_start_tag(tsx->p, el,
+				"tileset");
+	}
+}
+
+void XMLCALL
+xml_tileset_end(void *data, const char *el)
+{
+	struct tsx *tsx;
+
+	debug("</%s> (type \"tileset\")", el);
+
+	tsx = (struct tsx *) data;
+
+	if (xml_check_tag(el, "tileset")) {
+		XML_SetStartElementHandler(tsx->p, NULL);
+		XML_SetEndElementHandler(tsx->p, NULL);
+	} else {
+		xml_unexpected_end_tag(tsx->p, el,
+				"tileset");
+	}
+}
+
+struct tileset *
+tileset_get(const char *path)
+{
+	struct tsx tsx;
+	FILE *tsx_fp;
+	void *tsx_buf;
+	size_t len;
+	enum XML_Status status;
+
+	memset(&tsx, 0, sizeof(tsx));
+
+	tsx.ts = (struct tileset *) resource_get(&ts_res, path);
+	if (tsx.ts != NULL) {
+		resource_use((struct resource *) tsx.ts);
+		return tsx.ts;
+	}
+
+	tsx.ts = resource_alloc(path, sizeof(*tsx.ts));
+
+	tsx.p = XML_ParserCreate(NULL);
+	if (tsx.p == NULL) {
+		warn("Failed to create TSX parser");
+		return NULL;
+	}
+
+	XML_SetStartElementHandler(tsx.p, xml_tileset_start);
+	XML_SetEndElementHandler(tsx.p, NULL);
+	XML_SetCharacterDataHandler(tsx.p, NULL);
+
+	XML_SetUserData(tsx.p, &tsx);
+
+	tsx_fp = fopen(path, "rb");
+	if (tsx_fp == NULL) {
+		warn("Failed to open TSX file");
+		XML_ParserFree(tsx.p);
+		return NULL;
+	}
+
+	tsx_buf = XML_GetBuffer(tsx.p, 8192);
+	if (tsx_buf == NULL) {
+		warn("Failed to create TSX parse buffer");
+		XML_ParserFree(tsx.p);
+		fclose(tsx_fp);
+		return NULL;
+	}
+
+	while (!feof(tsx_fp)) {
+		len = fread(tsx_buf, 1, 8192, tsx_fp);
+		status = XML_ParseBuffer(tsx.p, len, feof(tsx_fp));
+		if (status == XML_STATUS_OK) {
+			continue;
+		}
+		warn("Failed to parse TSX file (%s)",
+				XML_ErrorString(XML_GetErrorCode(tsx.p)));
+		XML_ParserFree(tsx.p);
+		fclose(tsx_fp);
+		return NULL;
+	}
+
+	XML_ParserFree(tsx.p);
+	fclose(tsx_fp);
+
+	resource_use((struct resource *) tsx.ts);
+	resource_add(&ts_res, path, (struct resource *) tsx.ts);
+
+	return tsx.ts;
+}
diff --git a/src/resources/tileset.h b/src/resources/tileset.h
new file mode 100644
index 0000000..45de237
--- /dev/null
+++ b/src/resources/tileset.h
@@ -0,0 +1,23 @@
+#ifndef RESOURCE_TILESET_H
+#define RESOURCE_TILESET_H
+
+#include <expat.h>
+#include "resource.h"
+#include "image.h"
+
+struct tileset {
+	struct resource res;
+	int firstgid;
+	char *name;
+	int tilewidth;
+	int tileheight;
+	struct image *image;
+	struct tileset *next;
+};
+
+struct tileset *tileset_get(const char *path);
+void XMLCALL xml_tileset_start(void *data, const char *el,
+		const char **attr);
+void XMLCALL xml_tileset_end(void *data, const char *el);
+
+#endif
diff --git a/src/xml.c b/src/xml.c
new file mode 100644
index 0000000..68a72ed
--- /dev/null
+++ b/src/xml.c
@@ -0,0 +1,62 @@
+#include <string.h>
+#include <stdio.h>
+#include <expat.h>
+#include "xml.h"
+#include "logging.h"
+
+inline int
+xml_check_tag(const char *found, const char *expected)
+{
+	return strcmp(found, expected) != 0;
+}
+
+inline void
+xml_unexpected_start_tag(XML_Parser p, const char *found, const char *expected)
+{
+	warn("Found \"%s\" start tag where expected one of \"%s\" in map",
+			found, expected);
+	XML_StopParser(p, XML_FALSE);
+}
+
+inline void
+xml_unexpected_end_tag(XML_Parser p, const char *found, const char *expected)
+{
+	warn("Found \"%s\" end tag where expected one of \"%s\" in map",
+			found, expected);
+	XML_StopParser(p, XML_FALSE);
+}
+
+void
+xml_get_int_attr(XML_Parser p, const char **attr, const char *name,
+		int *dest, int req)
+{
+	for (; attr[0] != NULL; attr += 2) {
+		if (strcmp(attr[0], name) == 0) {
+			if (sscanf(attr[1], "%d", dest) == 1) {
+				return;
+			} else if (req) {
+				warn("Invalid \"%s\" attribute value", name);
+				XML_StopParser(p, XML_FALSE);
+			}
+		}
+	}
+	if (req) {
+		warn("Required attribute \"%s\" not found", name);
+		XML_StopParser(p, XML_FALSE);
+	}
+}
+
+void
+xml_get_string_attr(XML_Parser p, const char **attr, const char *name,
+		char **dest, int req)
+{
+	for (; attr[0] != NULL; attr += 2) {
+		if (strcmp(attr[0], name) == 0) {
+			*dest = strdup(attr[1]);
+		}
+	}
+	if (req) {
+		warn("Required attribute \"%s\" not found", name);
+		XML_StopParser(p, XML_FALSE);
+	}
+}
diff --git a/src/xml.h b/src/xml.h
new file mode 100644
index 0000000..07f9c80
--- /dev/null
+++ b/src/xml.h
@@ -0,0 +1,16 @@
+#ifndef XML_H
+#define XML_H
+
+#include <expat.h>
+
+extern inline int xml_check_tag(const char *found, const char *expected);
+extern inline void xml_unexpected_start_tag(XML_Parser p, const char *found,
+		const char *expected);
+extern inline void xml_unexpected_end_tag(XML_Parser p, const char *found,
+		const char *expected);
+void xml_get_int_attr(XML_Parser p, const char **attr, const char *name,
+		int *dest, int req);
+void xml_get_string_attr(XML_Parser p, const char **attr, const char *name,
+		char **dest, int req);
+
+#endif