Parser: make parser (mostly) reentrant

Introduce a parser_state structure, which describes (most) of the
global parser state. Create such a structure in the entry routines
to the parser and pass it down to the individual functions. The
parser state is initialized and freed with the init_parser_state()
and free_parser_state() functions.

The main benefits are:
1) Isolation of parser state.
2) Keeping the global name space tidy.
3) Prevent memory leaks which could happen in truncated files by
   freeing all the parser state after parse.

A somewhat controversial point might be that the individual
parsing functions are split in those that need parser-state and
those that don't. This means that there are now two versions of
the MATCH macro, viz. one for the former and one for the latter.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 72 insertions, 55 deletions

diff --git a/core/parse.h b/core/parse.h
index bcdbe03c6..d56609e79 100644
--- a/core/parse.h
+++ b/core/parse.h
@@ -9,20 +9,9 @@ typedef union {
 	char allocation[sizeof(struct event) + MAX_EVENT_NAME];
 } event_allocation_t;
 
-extern event_allocation_t event_allocation;
-#define cur_event event_allocation.event
-
 /*
  * Dive info as it is being built up..
  */
-extern struct divecomputer *cur_dc;
-extern struct dive *cur_dive;
-extern struct dive_site *cur_dive_site;
-extern location_t cur_location;
-extern dive_trip_t *cur_trip;
-extern struct sample *cur_sample;
-extern struct picture *cur_picture;
-
 
 struct parser_settings {
 	struct {
@@ -31,66 +20,94 @@ struct parser_settings {
 		const char *nickname, *serial_nr, *firmware;
 	} dc;
 };
-extern struct parser_settings cur_settings;
-
-extern bool in_settings;
-extern bool in_userid;
-extern struct tm cur_tm;
-extern int cur_cylinder_index, cur_ws_index;
-extern int lastcylinderindex, next_o2_sensor;
-extern int o2pressure_sensor;
-extern struct extra_data cur_extra_data;
 
 enum import_source {
 	UNKNOWN,
 	LIBDIVECOMPUTER,
 	DIVINGLOG,
 	UDDF,
-} import_source;
+};
+
+/*
+ * parser_state is the state needed by the parser(s). It is initialized
+ * with init_parser_state() and resources are freed with free_parser_state().
+ * "owning" marks pointers to objects that are freed in free_parser_state().
+ * In contrast, "non-owning" marks pointers to objects that are owned
+ * by other data-structures.
+ */
+struct parser_state {
+	bool metric;
+	struct parser_settings cur_settings;
+	enum import_source import_source;
+
+	struct divecomputer *cur_dc;		/* non-owning */
+	struct dive *cur_dive;			/* owning */
+	struct dive_site *cur_dive_site;	/* owning */
+	location_t cur_location;
+	dive_trip_t *cur_trip;			/* owning */
+	struct sample *cur_sample;		/* non-owning */
+	struct picture *cur_picture;		/* owning */
+	char *country, *city;			/* owning */
+
+	bool in_settings;
+	bool in_userid;
+	struct tm cur_tm;
+	int cur_cylinder_index, cur_ws_index;
+	int lastcylinderindex, next_o2_sensor;
+	int o2pressure_sensor;
+	struct extra_data cur_extra_data;
+	struct units xml_parsing_units;
+	struct dive_table *target_table;	/* non-owning */
+
+	sqlite3 *sql_handle;			/* for SQL based parsers */
+	event_allocation_t event_allocation;
+};
+
+#define cur_event event_allocation.event
+
+void init_parser_state(struct parser_state *state);
+void free_parser_state(struct parser_state *state);
 
 /* the dive table holds the overall dive list; target table points at
  * the table we are currently filling */
 extern struct dive_table dive_table;
-extern struct dive_table *target_table;
-
-extern int metric;
 
 int trimspace(char *buffer);
 void start_match(const char *type, const char *name, char *buffer);
 void nonmatch(const char *type, const char *name, char *buffer);
-void event_start(void);
-void event_end(void);
-struct divecomputer *get_dc(void);
-
-bool is_dive(void);
-void reset_dc_info(struct divecomputer *dc);
-void reset_dc_settings(void);
-void settings_start(void);
-void settings_end(void);
-void dc_settings_start(void);
-void dc_settings_end(void);
-void dive_site_start(void);
-void dive_site_end(void);
-void dive_start(void);
-void dive_end(void);
-void trip_start(void);
-void trip_end(void);
-void picture_start(void);
-void picture_end(void);
-void cylinder_start(void);
-void cylinder_end(void);
-void ws_start(void);
-void ws_end(void);
-
-void sample_start(void);
-void sample_end(void);
-void divecomputer_start(void);
-void divecomputer_end(void);
-void userid_start(void);
-void userid_stop(void);
+void event_start(struct parser_state *state);
+void event_end(struct parser_state *state);
+struct divecomputer *get_dc(struct parser_state *state);
+
+bool is_dive(struct parser_state *state);
+void reset_dc_info(struct divecomputer *dc, struct parser_state *state);
+void reset_dc_settings(struct parser_state *state);
+void settings_start(struct parser_state *state);
+void settings_end(struct parser_state *state);
+void dc_settings_start(struct parser_state *state);
+void dc_settings_end(struct parser_state *state);
+void dive_site_start(struct parser_state *state);
+void dive_site_end(struct parser_state *state);
+void dive_start(struct parser_state *state);
+void dive_end(struct parser_state *state);
+void trip_start(struct parser_state *state);
+void trip_end(struct parser_state *state);
+void picture_start(struct parser_state *state);
+void picture_end(struct parser_state *state);
+void cylinder_start(struct parser_state *state);
+void cylinder_end(struct parser_state *state);
+void ws_start(struct parser_state *state);
+void ws_end(struct parser_state *state);
+
+void sample_start(struct parser_state *state);
+void sample_end(struct parser_state *state);
+void divecomputer_start(struct parser_state *state);
+void divecomputer_end(struct parser_state *state);
+void userid_start(struct parser_state *state);
+void userid_stop(struct parser_state *state);
 void utf8_string(char *buffer, void *_res);
 
-void add_dive_site(char *ds_name, struct dive *dive);
+void add_dive_site(char *ds_name, struct dive *dive, struct parser_state *state);
 int atoi_n(char *ptr, unsigned int len);
 
 #endif