helper: Add string_choices.h

Add the helper function str_enabled_disabled() to select between the two
strings 'enabled' and 'disabled' depending on a boolean value.

Additional functions for frequently used strings can be added in the future
if required.

Change-Id: I2d8ae96b141f87966836e6e4c3a2ed6d12b71fa5
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/9006
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/helper/Makefile.am

@@ -32,6 +32,7 @@ noinst_LTLIBRARIES += %D%/libhelper.la
 	%D%/crc32.h \
 	%D%/time_support.h \
 	%D%/replacements.h \
+	%D%/string_choices.h \
 	%D%/fileio.h \
 	%D%/system.h \
 	%D%/jep106.h \

src/helper/string_choices.h

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef OPENOCD_HELPER_STRING_CHOICES_H
+#define OPENOCD_HELPER_STRING_CHOICES_H
+
+#include <helper/types.h>
+
+/*
+ * This file contains helper functions that return one of two strings depending
+ * on a boolean value. The format of these functions is 'str_$true_$false' where
+ * $true and $false are the two corresponding strings.
+ *
+ * These helper functions are beneficial because they improve code consistency
+ * and reduce the number of hardcoded strings.
+ */
+
+static inline const char *str_enabled_disabled(bool value)
+{
+	return value ? "enabled" : "disabled";
+}
+
+#endif /* OPENOCD_HELPER_STRING_CHOICES_H */