Trim down the use of ep_ memory in the display filter code.

Couldn't quite eliminate it completely, but it's much improved.  Need to figure out where/when to free dfilter_error_msg.

Change-Id: I10216e9546d38e83f69991ded8ec0b3fc8472035
Reviewed-on: https://code.wireshark.org/review/6591
Reviewed-by: Michael Mann <mmann78@netscape.net>

4 files changed, 31 insertions, 22 deletions

diff --git a/epan/dfilter/dfilter-macro.c b/epan/dfilter/dfilter-macro.c
index fef1f2c561..578bac60c6 100644
--- a/epan/dfilter/dfilter-macro.c
+++ b/epan/dfilter/dfilter-macro.c
@@ -110,7 +110,7 @@ void dfilter_macro_save(const gchar* filename, gchar** error) {
 	FILE* f = ws_fopen(filename,"w");
 
 	if (!f) {
-		*error = ep_strdup_printf("Could not open file: '%s', error: %s\n", filename, g_strerror(errno) );
+		*error = wmem_strdup_printf(NULL, "Could not open file: '%s', error: %s\n", filename, g_strerror(errno) );
 		return;
 	}
 
@@ -146,14 +146,14 @@ void dfilter_macro_dump(void) {
 #endif
 }
 
-static const gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar** error) {
+static gchar* dfilter_macro_resolve(gchar* name, gchar** args, gchar** error) {
 	GString* text;
 	int argc = 0;
 	dfilter_macro_t* m = NULL;
 	fvt_cache_entry_t* e;
 	int* arg_pos_p;
 	gchar** parts;
-	const gchar* ret;
+	gchar* ret;
 	guint i;
 
 	for (i = 0; i < num_macros; i++) {
@@ -168,13 +168,13 @@ static const gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar
 		if (fvt_cache &&
 		    (e = (fvt_cache_entry_t  *)g_hash_table_lookup(fvt_cache,name)) != NULL) {
 			if(e->usable) {
-				return e->repr;
+				return wmem_strdup(NULL, e->repr);
 			} else {
-				*error = ep_strdup_printf("macro '%s' is unusable", name);
+				*error = wmem_strdup_printf(NULL, "macro '%s' is unusable", name);
 				return NULL;
 			}
 		} else {
-			*error = ep_strdup_printf("macro '%s' does not exist", name);
+			*error = wmem_strdup_printf(NULL, "macro '%s' does not exist", name);
 			return NULL;
 		}
 	}
@@ -186,7 +186,7 @@ static const gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar
 	}
 
 	if (argc != m->argc) {
-		*error = ep_strdup_printf("wrong number of arguments for macro '%s', expecting %d instead of %d",
+		*error = wmem_strdup_printf(NULL, "wrong number of arguments for macro '%s', expecting %d instead of %d",
 								  name, m->argc, argc);
 		return NULL;
 	}
@@ -204,7 +204,7 @@ static const gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar
 		}
 	}
 
-	ret = ep_strdup(text->str);
+	ret = wmem_strdup(NULL, text->str);
 
 	g_string_free(text,TRUE);
 
@@ -212,7 +212,7 @@ static const gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar
 }
 
 
-static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth, const gchar** error) {
+static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth, gchar** error) {
 	enum { OUTSIDE, STARTING, NAME, ARGS } state = OUTSIDE;
 	GString* out;
 	GString* name = NULL;
@@ -223,7 +223,7 @@ static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth,
 	gboolean changed = FALSE;
 
 	if ( depth > 31) {
-		*error = "too much nesting in macros";
+		*error = wmem_strdup(NULL, "too much nesting in macros");
 		return NULL;
 	}
 
@@ -290,7 +290,7 @@ static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth,
 				} else if ( c == ':') {
 					state = ARGS;
 				} else if ( c == '}') {
-					const gchar* resolved;
+					gchar* resolved;
 
 					g_ptr_array_add(args,NULL);
 
@@ -300,22 +300,23 @@ static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth,
 					changed = TRUE;
 
 					g_string_append(out,resolved);
+					wmem_free(NULL, resolved);
 
 					FREE_ALL();
 
 					state = OUTSIDE;
 				} else if ( c == '\0') {
-					*error = "end of filter in the middle of a macro expression";
+					*error = wmem_strdup(NULL, "end of filter in the middle of a macro expression");
 					goto on_error;
 				} else {
-					*error = "invalid char in macro name";
+					*error = wmem_strdup(NULL, "invalid char in macro name");
 					goto on_error;
 				}
 				break;
 			} case ARGS: {
 				switch(c) {
 					case '\0': {
-						*error = "end of filter in the middle of a macro expression";
+						*error = wmem_strdup(NULL, "end of filter in the middle of a macro expression");
 						goto on_error;
 					} case ';': {
 						g_ptr_array_add(args,g_string_free(arg,FALSE));
@@ -328,14 +329,14 @@ static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth,
 							g_string_append_c(arg,c);
 							break;
 						} else {
-							*error = "end of filter in the middle of a macro expression";
+							*error = wmem_strdup(NULL, "end of filter in the middle of a macro expression");
 							goto on_error;
 						}
 					} default: {
 						g_string_append_c(arg,c);
 						break;
 					} case '}': {
-						const gchar* resolved;
+						gchar* resolved;
 						g_ptr_array_add(args,g_string_free(arg,FALSE));
 						g_ptr_array_add(args,NULL);
 
@@ -347,6 +348,7 @@ static const gchar* dfilter_macro_apply_recurse(const gchar* text, guint depth,
 						changed = TRUE;
 
 						g_string_append(out,resolved);
+						wmem_free(NULL, resolved);
 
 						FREE_ALL();
 
@@ -368,7 +370,7 @@ finish:
 			g_string_free(out,TRUE);
 			return (*error) ? NULL : resolved;
 		} else {
-			const gchar* out_str = ep_strdup(out->str);
+			const gchar* out_str = wmem_strdup(NULL, out->str);
 			g_string_free(out,TRUE);
 			return out_str;
 		}
@@ -376,13 +378,13 @@ finish:
 on_error:
 	{
 		FREE_ALL();
-		if (! *error) *error = "unknown error in macro expression";
+		if (! *error) *error = wmem_strdup(NULL, "unknown error in macro expression");
 		g_string_free(out,TRUE);
 		return NULL;
 	}
 }
 
-const gchar* dfilter_macro_apply(const gchar* text, const gchar** error) {
+const gchar* dfilter_macro_apply(const gchar* text, gchar** error) {
 	return dfilter_macro_apply_recurse(text, 0, error);
 }
 
diff --git a/epan/dfilter/dfilter-macro.h b/epan/dfilter/dfilter-macro.h
index eda1cfc050..68462529ac 100644
--- a/epan/dfilter/dfilter-macro.h
+++ b/epan/dfilter/dfilter-macro.h
@@ -50,7 +50,7 @@ void dfilter_macro_save(const gchar*, gchar**);
 void dfilter_macro_dump(void);
 
 /* applies all macros to the given text and returns the resulting string or NULL on failure */
-const gchar* dfilter_macro_apply(const gchar* text, const gchar** error);
+const gchar* dfilter_macro_apply(const gchar* text, gchar** error);
 
 void dfilter_macro_init(void);
 
diff --git a/epan/dfilter/dfilter.c b/epan/dfilter/dfilter.c
index 96c13c2115..8e21d30853 100644
--- a/epan/dfilter/dfilter.c
+++ b/epan/dfilter/dfilter.c
@@ -216,6 +216,7 @@ dfilter_compile(const gchar *text, dfilter_t **dfp)
 	guint		i;
 	/* XXX, GHashTable */
 	GPtrArray	*deprecated;
+	gchar *temp_error_msg;
 
 	g_assert(dfp);
 
@@ -226,7 +227,10 @@ dfilter_compile(const gchar *text, dfilter_t **dfp)
 
 	dfilter_error_msg = NULL;
 
-	if ( !( text = dfilter_macro_apply(text, &dfilter_error_msg) ) ) {
+	if ( !( text = dfilter_macro_apply(text, &temp_error_msg) ) ) {
+		/* Move the ep_ allocation up a layer */
+		dfilter_error_msg = ep_strdup(temp_error_msg);
+		wmem_free(NULL, temp_error_msg);
 		return FALSE;
 	}
 
@@ -350,6 +354,7 @@ dfilter_compile(const gchar *text, dfilter_t **dfp)
 	}
 	/* SUCCESS */
 	dfwork_free(dfw);
+	wmem_free(NULL, (char*)text);
 	return TRUE;
 
 FAILURE:
@@ -362,6 +367,7 @@ FAILURE:
 	}
 	g_ptr_array_free(deprecated, TRUE);
 	dfilter_fail("Unable to parse filter string \"%s\".", text);
+	wmem_free(NULL, (char*)text);
 	*dfp = NULL;
 	return FALSE;
 
diff --git a/epan/dfilter/dfunctions.c b/epan/dfilter/dfunctions.c
index 0ce74faaae..6394a1e482 100644
--- a/epan/dfilter/dfunctions.c
+++ b/epan/dfilter/dfunctions.c
@@ -46,7 +46,7 @@ string_walk(GList* arg1list, GList **retval, gchar(*conv_func)(gchar))
         arg_fvalue = (fvalue_t *)arg1->data;
         /* XXX - it would be nice to handle FT_TVBUFF, too */
         if (IS_FT_STRING(fvalue_type_ftenum(arg_fvalue))) {
-            s = (char *)ep_strdup((gchar *)fvalue_get(arg_fvalue));
+            s = (char *)wmem_strdup(NULL, (gchar *)fvalue_get(arg_fvalue));
             for (c = s; *c; c++) {
                     /**c = g_ascii_tolower(*c);*/
                     *c = conv_func(*c);
@@ -54,6 +54,7 @@ string_walk(GList* arg1list, GList **retval, gchar(*conv_func)(gchar))
 
             new_ft_string = fvalue_new(FT_STRING);
             fvalue_set_string(new_ft_string, s);
+            wmem_free(NULL, s);
             *retval = g_list_append(*retval, new_ft_string);
 	}
         arg1 = arg1->next;