common: compile argpar-utils as C++

[lttng-tools.git] / src / common / argpar-utils / argpar-utils.cpp

diff --git a/src/common/argpar-utils/argpar-utils.cpp b/src/common/argpar-utils/argpar-utils.cpp
new file mode 100644 (file)
index 0000000..4935986
--- /dev/null
+++ b/src/common/argpar-utils/argpar-utils.cpp
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2021 Simon Marchi <simon.marchi@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include "argpar-utils.h"
+
+#include <stdio.h>
+
+#include <common/error.h>
+#include <common/string-utils/string-utils.h>
+
+/*
+ * Given argpar error status `status` and error `error`, return a formatted
+ * error message describing the error.
+ *
+ * `argv` is the argument vector that was being parsed.
+ *
+ * `context_fmt`, if non-NULL, is formatted using `args` and prepended to the
+ * error message.
+ *
+ * Add `argc_offset` the the argument index mentioned in the error message.
+ *
+ * The returned string must be freed by the caller.
+ */
+static ATTR_FORMAT_PRINTF(4, 0)
+char *format_arg_error_v(const struct argpar_error *error, int argc_offset,
+               const char **argv, const char *context_fmt, va_list args)
+{
+       char *str = NULL;
+       char *str_ret = NULL;
+       int ret;
+
+       if (context_fmt) {
+               ret = vasprintf(&str, context_fmt, args);
+               if (ret == -1) {
+                       /*
+                        * If vasprintf fails, the content of str is undefined,
+                        * and we shouldn't try to free it.
+                        */
+                       str = NULL;
+                       goto end;
+               }
+
+               ret = strutils_append_str(&str, ": ");
+               if (ret < 0) {
+                       goto end;
+               }
+       }
+
+       switch (argpar_error_type(error))
+       {
+       case ARGPAR_ERROR_TYPE_MISSING_OPT_ARG:
+       {
+               const int orig_index = argpar_error_orig_index(error);
+               const char *arg = argv[orig_index];
+
+               ret = strutils_appendf(&str,
+                       WHILE_PARSING_ARG_N_ARG_FMT "Missing required argument for option `%s`",
+                       orig_index + 1 + argc_offset, argv[orig_index], arg);
+               if (ret < 0) {
+                       goto end;
+               }
+
+               break;
+       }
+       case ARGPAR_ERROR_TYPE_UNEXPECTED_OPT_ARG:
+       {
+               bool is_short;
+               const struct argpar_opt_descr *descr =
+                       argpar_error_opt_descr(error, &is_short);
+               int orig_index = argpar_error_orig_index(error);
+               const char *arg = argv[orig_index];
+
+               if (is_short) {
+                       ret = strutils_appendf(&str,
+                               WHILE_PARSING_ARG_N_ARG_FMT "Unexpected argument for option `-%c`",
+                               orig_index + 1 + argc_offset, arg, descr->short_name);
+               } else {
+                       ret = strutils_appendf(&str,
+                               WHILE_PARSING_ARG_N_ARG_FMT "Unexpected argument for option `--%s`",
+                               orig_index + 1 + argc_offset, arg, descr->long_name);
+               }
+
+               if (ret < 0) {
+                       goto end;
+               }
+
+               break;
+       }
+       case ARGPAR_ERROR_TYPE_UNKNOWN_OPT:
+       {
+               int orig_index = argpar_error_orig_index(error);
+               const char *unknown_opt = argpar_error_unknown_opt_name(error);
+
+               ret = strutils_appendf(&str,
+                       WHILE_PARSING_ARG_N_ARG_FMT "Unknown option `%s`",
+                       orig_index + 1 + argc_offset, argv[orig_index], unknown_opt);
+
+               if (ret < 0) {
+                       goto end;
+               }
+
+               break;
+       }
+       default:
+               abort ();
+       }
+
+       str_ret = str;
+       str = NULL;
+
+end:
+       free(str);
+       return str_ret;
+}
+
+enum parse_next_item_status parse_next_item(struct argpar_iter *iter,
+               const struct argpar_item **item, int argc_offset,
+               const char **argv, bool unknown_opt_is_error,
+               const struct argpar_error **error_out,
+               const char *context_fmt, ...)
+{
+       enum argpar_iter_next_status status;
+       const struct argpar_error *error = NULL;
+       enum parse_next_item_status ret;
+
+       ARGPAR_ITEM_DESTROY_AND_RESET(*item);
+       status = argpar_iter_next(iter, item, &error);
+
+       switch (status) {
+       case ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY:
+               ERR("Failed to get next argpar item.");
+               ret = PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY;
+               break;
+       case ARGPAR_ITER_NEXT_STATUS_ERROR:
+       {
+               va_list args;
+               char *err_str;
+
+               if (argpar_error_type(error) == ARGPAR_ERROR_TYPE_UNKNOWN_OPT &&
+                               !unknown_opt_is_error) {
+                       ret = PARSE_NEXT_ITEM_STATUS_END;
+                       break;
+               }
+
+               va_start(args, context_fmt);
+               err_str = format_arg_error_v(error, argc_offset, argv,
+                       context_fmt, args);
+               va_end(args);
+
+               if (err_str) {
+                       ERR("%s", err_str);
+                       free(err_str);
+               } else {
+                       ERR("%s", "Failed to format argpar error.");
+               }
+
+               ret = PARSE_NEXT_ITEM_STATUS_ERROR;
+               break;
+       }
+       case ARGPAR_ITER_NEXT_STATUS_END:
+               ret = PARSE_NEXT_ITEM_STATUS_END;
+               break;
+       case ARGPAR_ITER_NEXT_STATUS_OK:
+               ret = PARSE_NEXT_ITEM_STATUS_OK;
+               break;
+       default:
+               abort();
+       }
+
+       if (error_out) {
+               argpar_error_destroy(*error_out);
+               *error_out = error;
+               error = NULL;
+       }
+
+       argpar_error_destroy(error);
+
+       return ret;
+}