core: convert save-xml.c to C++

This includes using the C++ version of membuffer. There appears
to not have been a leak, because the buffer is freed in
flush_buffer(), but usage was somewhat inconsistent and hard to
follow.

Also, convert some string handling to std::string to avoid free()
madness.

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

Subsurface-mobile.pro

@@ -82,7 +82,7 @@ SOURCES += subsurface-mobile-main.cpp \
 	core/datatrak.c \
 	core/ostctools.c \
 	core/planner.c \
-	core/save-xml.c \
+	core/save-xml.cpp \
 	core/cochran.c \
 	core/deco.c \
 	core/divesite.c \

core/CMakeLists.txt

@@ -159,7 +159,7 @@ set(SUBSURFACE_CORE_LIB_SRCS
 	save-html.c
 	save-html.h
 	save-profiledata.c
-	save-xml.c
+	save-xml.cpp
 	selection.cpp
 	selection.h
 	sha1.c

core/save-xml.cpp

@@ -54,7 +54,6 @@ static void quote(struct membuffer *b, const char *text, int is_attribute)
 static void show_utf8(struct membuffer *b, const char *text, const char *pre, const char *post, int is_attribute)
 {
 	int len;
-	char *cleaned;
 
 	if (!text)
 		return;
@@ -69,27 +68,25 @@ static void show_utf8(struct membuffer *b, const char *text, const char *pre, co
 		return;
 	while (len && isascii(text[len - 1]) && isspace(text[len - 1]))
 		len--;
-	cleaned = strndup(text, len);
+	std::string cleaned(text, len);
 	put_string(b, pre);
-	quote(b, cleaned, is_attribute);
+	quote(b, cleaned.c_str(), is_attribute);
 	put_string(b, post);
-	free(cleaned);
 }
 
-static void blankout(char *c)
+static void blankout(std::string &s)
 {
-	while(*c) {
-		switch (*c) {
+	for(char &c: s) {
+		switch (c) {
 		case 'A'...'Z':
-			*c = 'X';
+			c = 'X';
 			break;
 		case 'a'...'z':
-			*c = 'x';
+			c = 'x';
 			break;
 		default:
 			;
 		}
-		++c;
 	}
 }
 
@@ -97,12 +94,11 @@ static void show_utf8_blanked(struct membuffer *b, const char *text, const char
 {
 	if (!text)
 		return;
-	char *copy = strdup(text);
+	std::string copy(text);
 
 	if (anonymize)
 		blankout(copy);
-	show_utf8(b, copy, pre, post, is_attribute);
-	free(copy);
+	show_utf8(b, copy.c_str(), pre, post, is_attribute);
 }
 
 static void save_depths(struct membuffer *b, struct divecomputer *dc)
@@ -432,7 +428,7 @@ static void save_samples(struct membuffer *b, struct dive *dive, struct divecomp
 	int nr;
 	int o2sensor;
 	struct sample *s;
-	struct sample dummy = { .bearing.degrees = -1, .ndl.seconds = -1 };
+	struct sample dummy;
 
 	/* Set up default pressure sensor indices */
 	o2sensor = legacy_format_o2pressures(dive, dc);
@@ -464,8 +460,8 @@ static void save_dc(struct membuffer *b, struct dive *dive, struct divecomputer
 	if (dc->duration.seconds && dc->duration.seconds != dive->dc.duration.seconds)
 		put_duration(b, dc->duration, " duration='", " min'");
 	if (dc->divemode != OC) {
-		for (enum divemode_t i = 0; i < NUM_DIVEMODE; i++)
-			if (dc->divemode == i)
+		int i = (int)dc->divemode;
+		if (i >= 0 && i < NUM_DIVEMODE)
 			show_utf8(b, divemode_text[i], " dctype='", "'", 1);
 		if (dc->no_o2sensors)
 			put_format(b," no_o2sensors='%d'", dc->no_o2sensors);
@@ -502,7 +498,7 @@ static void save_picture(struct membuffer *b, struct picture *pic)
 	put_string(b, "/>\n");
 }
 
-void save_one_dive_to_mb(struct membuffer *b, struct dive *dive, bool anonymize)
+extern "C" void save_one_dive_to_mb(struct membuffer *b, struct dive *dive, bool anonymize)
 {
 	struct divecomputer *dc;
 	pressure_t surface_pressure = un_fixup_surface_pressure(dive);
@@ -561,9 +557,9 @@ void save_one_dive_to_mb(struct membuffer *b, struct dive *dive, bool anonymize)
 	put_format(b, "</dive>\n");
 }
 
-int save_dive(FILE *f, struct dive *dive, bool anonymize)
+extern "C" int save_dive(FILE *f, struct dive *dive, bool anonymize)
 {
-	struct membuffer buf = { 0 };
+	struct membufferpp buf;
 
 	save_one_dive_to_mb(&buf, dive, anonymize);
 	flush_buffer(&buf, f);
@@ -634,7 +630,7 @@ static void save_one_fingerprint(struct membuffer *b, int i)
 	free(data);
 }
 
-int save_dives(const char *filename)
+extern "C" int save_dives(const char *filename)
 {
 	return save_dives_logic(filename, false, false);
 }
@@ -780,8 +776,7 @@ static void save_dives_buffer(struct membuffer *b, bool select_only, bool anonym
 static void save_backup(const char *name, const char *ext, const char *new_ext)
 {
 	int len = strlen(name);
-	int a = strlen(ext), b = strlen(new_ext);
-	char *newname;
+	int a = strlen(ext);
 
 	/* len up to and including the final '.' */
 	len -= a;
@@ -793,20 +788,15 @@ static void save_backup(const char *name, const char *ext, const char *new_ext)
 	if (strncasecmp(name + len, ext, a))
 		return;
 
-	newname = malloc(len + b + 1);
-	if (!newname)
-		return;
-
-	memcpy(newname, name, len);
-	memcpy(newname + len, new_ext, b + 1);
+	std::string newname(name, len);
+	newname += new_ext;
 
 	/*
 	 * Ignore errors. Maybe we can't create the backup file,
 	 * maybe no old file existed.  Regardless, we'll write the
 	 * new file.
 	 */
-	(void) subsurface_rename(name, newname);
-	free(newname);
+	(void) subsurface_rename(name, newname.c_str());
 }
 
 static void try_to_backup(const char *filename)
@@ -820,11 +810,8 @@ static void try_to_backup(const char *filename)
 		int elen = strlen(extension[i]);
 		if (strcasecmp(filename + flen - elen, extension[i]) == 0) {
 			if (last_xml_version < DATAFORMAT_VERSION) {
-				int se_len = strlen(extension[i]) + 5;
-				char *special_ext = malloc(se_len);
-				snprintf(special_ext, se_len, "%s.v%d", extension[i], last_xml_version);
-				save_backup(filename, extension[i], special_ext);
-				free(special_ext);
+				std::string special_ext = std::string(extension[i]) + ".v" + std::to_string(last_xml_version);
+				save_backup(filename, extension[i], special_ext.c_str());
 			} else {
 				save_backup(filename, extension[i], "bak");
 			}
@@ -834,9 +821,9 @@ static void try_to_backup(const char *filename)
 	}
 }
 
-int save_dives_logic(const char *filename, const bool select_only, bool anonymize)
+extern "C" int save_dives_logic(const char *filename, const bool select_only, bool anonymize)
 {
-	struct membuffer buf = { 0 };
+	struct membufferpp buf;
 	struct git_info info;
 	FILE *f;
 	int error = 0;
@@ -863,7 +850,6 @@ int save_dives_logic(const char *filename, const bool select_only, bool anonymiz
 	if (error)
 		report_error(translate("gettextFromC", "Failed to save dives to %s (%s)"), filename, strerror(errno));
 
-	free_buffer(&buf);
 	return error;
 }
 
@@ -880,7 +866,7 @@ int export_dives_xslt(const char *filename, const bool selected, const int units
 static int export_dives_xslt_doit(const char *filename, struct xml_params *params, bool selected, int units, const char *export_xslt, bool anonymize)
 {
 	FILE *f;
-	struct membuffer buf = { 0 };
+	struct membufferpp buf;
 	xmlDoc *doc;
 	xsltStylesheetPtr xslt = NULL;
 	xmlDoc *transformed;
@@ -901,7 +887,6 @@ static int export_dives_xslt_doit(const char *filename, struct xml_params *param
 	 * the XML into a character buffer.
 	 */
 	doc = xmlReadMemory(buf.buffer, buf.len, "divelog", NULL, XML_PARSE_HUGE | XML_PARSE_RECOVER);
-	free_buffer(&buf);
 	if (!doc)
 		return report_error("Failed to read XML memory");
 
@@ -961,9 +946,9 @@ static void save_dive_sites_buffer(struct membuffer *b, const struct dive_site *
 	put_format(b, "</divesites>\n");
 }
 
-int save_dive_sites_logic(const char *filename, const struct dive_site *sites[], int nr_sites, bool anonymize)
+extern "C" int save_dive_sites_logic(const char *filename, const struct dive_site *sites[], int nr_sites, bool anonymize)
 {
-	struct membuffer buf = { 0 };
+	struct membufferpp buf;
 	FILE *f;
 	int error = 0;
 
@@ -983,6 +968,5 @@ int save_dive_sites_logic(const char *filename, const struct dive_site *sites[],
 	if (error)
 		report_error(translate("gettextFromC", "Failed to save divesites to %s (%s)"), filename, strerror(errno));
 
-	free_buffer(&buf);
 	return error;
 }