Use a union in fieldset->value

Instead of unreliably casting uint64_t's to (void *)

src/fieldset.c

@@ -36,7 +36,7 @@ fieldset_t *fs_new_fieldset(void)
 }
 
 static inline void fs_add_word(fieldset_t *fs, const char *name, int type,
-		int free_, size_t len, void *value)
+		int free_, size_t len, field_val_t value)
 {
 	if (fs->len + 1 >= MAX_FIELDS) {
 		log_fatal("fieldset", "out of room in fieldset");
@@ -46,24 +46,24 @@ static inline void fs_add_word(fieldset_t *fs, const char *name, int type,
 	f->type = type;
 	f->name = name;
 	f->len = len;
-	f->value = (uint64_t) value;
+	f->value = value;
 	f->free_ = free_;
 }
 
 static void fs_modify_word(fieldset_t *fs, const char *name, int type,
-		int free_, size_t len, void *value)
+		int free_, size_t len, field_val_t value)
 {
 	int i;
 	for (i=0; i<fs->len; i++) {
 		if (!strcmp(fs->fields[i].name, name)) {
 			if (fs->fields[i].free_) {
-				free((void*)fs->fields[i].value);
+				free(fs->fields[i].value.ptr);
-				fs->fields[i].value = 0;
+				fs->fields[i].value.ptr = NULL;
 			}
 			fs->fields[i].type = type;
 			fs->fields[i].free_ = free_;
 			fs->fields[i].len = len;
-			fs->fields[i].value = (uint64_t)value;
+			fs->fields[i].value = value;
 			return;
 		}
 	}
@@ -72,55 +72,63 @@ static void fs_modify_word(fieldset_t *fs, const char *name, int type,
 
 void fs_add_null(fieldset_t *fs, const char *name)
 {
-	fs_add_word(fs, name, FS_NULL, 0, 0, NULL);
+	field_val_t val = { .ptr = NULL };
+	fs_add_word(fs, name, FS_NULL, 0, 0, val);
 }
 
 void fs_add_string(fieldset_t *fs, const char *name, char *value, int free_)
 {
-	fs_add_word(fs, name, FS_STRING, free_, strlen(value), (void*) value);
+	field_val_t val = { .ptr = value };
+	fs_add_word(fs, name, FS_STRING, free_, strlen(value), val);
 }
 
 void fs_add_uint64(fieldset_t *fs, const char *name, uint64_t value)
 {
-	fs_add_word(fs, name, FS_UINT64, 0, sizeof(uint64_t), (void*) value);
+	field_val_t val = { .num = value };
+	fs_add_word(fs, name, FS_UINT64, 0, sizeof(uint64_t), val);
 }
 
 void fs_add_binary(fieldset_t *fs, const char *name, size_t len,
 		void *value, int free_)
 {
-	fs_add_word(fs, name, FS_BINARY, free_, len, value);
+	field_val_t val = { .ptr = value };
+	fs_add_word(fs, name, FS_BINARY, free_, len, val);
 }
 
 // Modify
 void fs_modify_null(fieldset_t *fs, const char *name)
 {
-	fs_modify_word(fs, name, FS_NULL, 0, 0, NULL);
+	field_val_t val = { .ptr = NULL };
+	fs_modify_word(fs, name, FS_NULL, 0, 0, val);
 }
 
 void fs_modify_string(fieldset_t *fs, const char *name, char *value, int free_)
 {
-	fs_modify_word(fs, name, FS_STRING, free_, strlen(value), (void*) value);
+	field_val_t val = { .ptr = value };
+	fs_modify_word(fs, name, FS_STRING, free_, strlen(value), val);
 }
 
 void fs_modify_uint64(fieldset_t *fs, const char *name, uint64_t value)
 {
-	fs_modify_word(fs, name, FS_UINT64, 0, sizeof(uint64_t), (void*) value);
+	field_val_t val = { .num = value };
+	fs_modify_word(fs, name, FS_UINT64, 0, sizeof(uint64_t), val);
 }
 
 void fs_modify_binary(fieldset_t *fs, const char *name, size_t len,
 		void *value, int free_)
 {
-	fs_modify_word(fs, name, FS_BINARY, free_, len, value);
+	field_val_t val = { .ptr = value };
+	fs_modify_word(fs, name, FS_BINARY, free_, len, val);
 }
 
 uint64_t fs_get_uint64_by_index(fieldset_t *fs, int index)
 {
-	return (uint64_t) fs->fields[index].value;
+	return (uint64_t) fs->fields[index].value.num;
 }
 
 char* fs_get_string_by_index(fieldset_t *fs, int index)
 {
-	return (char*) fs->fields[index].value;
+	return (char*) fs->fields[index].value.ptr;
 }
 
 int fds_get_index_by_name(fielddefset_t *fds, char *name)
@@ -141,7 +149,7 @@ void fs_free(fieldset_t *fs)
 	for (int i=0; i < fs->len; i++) {
 		field_t *f = &(fs->fields[i]);
 		if (f->free_) {
-			free((void*) f->value);
+			free(f->value.ptr);
 		}
 	}
 	free(fs);

src/fieldset.h

@@ -36,13 +36,18 @@ typedef struct fielddef_set {
 	int len;
 } fielddefset_t;
 
+typedef union field_val {
+	void	  *ptr;
+	uint64_t   num;
+} field_val_t;
+
 // the internal field type used by fieldset
 typedef struct field {
 	const char *name;
 	int type;
 	int free_;
 	size_t len;
-	uint64_t value;
+	union field_val value;
 } field_t;
 
 // data structure that is populated by the probe module

src/output_modules/module_csv.c

@@ -79,11 +79,11 @@ int csv_process(fieldset_t *fs)
 			fprintf(file, ", ");
 		}
 		if (f->type == FS_STRING) {
-			fprintf(file, "%s", (char*) f->value); 
+			fprintf(file, "%s", (char*) f->value.ptr);
 		} else if (f->type == FS_UINT64) {
-			fprintf(file, "%lu", (uint64_t) f->value); 
+			fprintf(file, "%llu", (uint64_t) f->value.num);
 		} else if (f->type == FS_BINARY) {
-			hex_encode(file, (unsigned char*) f->value, f->len);
+			hex_encode(file, (unsigned char*) f->value.ptr, f->len);
 		} else if (f->type == FS_NULL) {
 			// do nothing
 		} else {