libflashrom: Add API to get the list of supported programmers

There were no options available to obtain the list of programmers.
The implementation is based on flashrom_supported_flash_chips.
Arrays of constant strings are returned, and the array must be
freed using flashrom_data_free.

Testing: Both unit tests and CLI tools serve as libflashrom clients.
    All unit tests run successfully.

Change-Id: Ib5275b742b849183b1fe701900040fee369a1d78
Signed-off-by: Dmitry Zhadinets <dzhadinets@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/86921
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Peter Marheine <pmarheine@chromium.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>

include/libflashrom.h

@@ -193,6 +193,14 @@ struct flashrom_chipset_info {
  * @return flashrom version
  */
 const char *flashrom_version_info(void);
+/**
+ * @brief Returns list of supported programmers
+ * The last entry in the returned list is followed by a NULL.
+ *
+ * @return List of supported programmers, or NULL if an error occurred.
+ *  The pointer must be freed after using flashrom_data_free
+ */
+const char **flashrom_supported_programmers(void);
 /**
  * @brief Returns list of supported flash chips
  * @return List of supported flash chips, or NULL if an error occurred

libflashrom.c

@@ -194,6 +194,18 @@ const char *flashrom_version_info(void)
 	return flashrom_version;
 }
 
+const char **flashrom_supported_programmers(void)
+{
+	const char **result = malloc(sizeof(char*) * (programmer_table_size + 1));
+	if (!result)
+		return NULL;
+	for (unsigned int i = 0; i < programmer_table_size; ++i) {
+		result[i] = programmer_table[i]->name;
+	}
+	result[programmer_table_size] = 0;
+	return result;
+}
+
 struct flashrom_flashchip_info *flashrom_supported_flash_chips(void)
 {
 	struct flashrom_flashchip_info *supported_flashchips =

libflashrom.map

@@ -32,6 +32,7 @@ LIBFLASHROM_1.0 {
     flashrom_supported_boards;
     flashrom_supported_chipsets;
     flashrom_supported_flash_chips;
+    flashrom_supported_programmers;
     flashrom_version_info;
     flashrom_wp_cfg_new;
     flashrom_wp_cfg_release;

tests/libflashrom.c

@@ -1,7 +1,7 @@
 /*
  * This file is part of the flashrom project.
  *
- * Copyright 2025 Dmitry Zhadinets (dzhadinets@gmail.com)
+ * Copyright 2025 Dmitry Zhadinets <dzhadinets@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -96,4 +96,21 @@ void flashrom_set_log_level_test_success(void **state)
 	/* check that callback is called after the change*/
 	assert_int_equal(print(FLASHROM_MSG_INFO, "1%s", "\n"), 0x666 + (int)FLASHROM_MSG_INFO);
 	flashrom_set_log_callback(NULL);
-}
+}
+
+void flashrom_supported_programmers_test_success(void **state)
+{
+	(void) state; /* unused */
+	const char **array = flashrom_supported_programmers();
+	const char **ptr = array;
+
+	assert_non_null(array);
+
+	do {
+		assert_non_null(*ptr);
+	}while (*(++ptr));
+
+	flashrom_data_free(array);
+
+	assert_int_not_equal(ptr - array, 0);
+}

tests/tests.c

@@ -482,6 +482,7 @@ int main(int argc, char *argv[])
 		cmocka_unit_test(flashrom_set_log_callback_test_success),
 		cmocka_unit_test(flashrom_set_log_callback_v2_test_success),
 		cmocka_unit_test(flashrom_set_log_level_test_success),
+		cmocka_unit_test(flashrom_supported_programmers_test_success),
 	};
 	ret |= cmocka_run_group_tests_name("libflashrom.c tests", libflashrom_tests, NULL, NULL);
 

tests/tests.h

@@ -35,6 +35,7 @@ void flashbuses_to_text_test_success(void **state);
 void flashrom_set_log_callback_test_success(void **state);
 void flashrom_set_log_callback_v2_test_success(void **state);
 void flashrom_set_log_level_test_success(void **state);
+void flashrom_supported_programmers_test_success(void **state);
 
 /* spi25.c */
 void spi_write_enable_test_success(void **state);