libflashrom: Add new layout_compare() function with test

Add a new layout_compare() function which will be used in a subsequent
patch to test equality between two layouts. Add a test function for
layout_compare(). Fix a small bug in compare_region_with_dump() which
was introduced in commit 74a1a54892 ("libflashrom: Fix comparison of
layout romentry regions"), which was discovered with the new test.

Change-Id: Ib37556bb83d4e1c26545a90b49128f1f78ffe2c6
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/89629
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

include/libflashrom.h

@@ -550,6 +550,21 @@ int flashrom_layout_get_region_range(struct flashrom_layout *layout, const char
  * @param layout Layout to free.
  */
 void flashrom_layout_release(struct flashrom_layout *layout);
+/**
+ * @brief Compare two flashrom layouts for equality.
+ *
+ * Compares all regions in both layouts. Two layouts are considered equal if they
+ * contain the same number of regions, in the same order, with identical start/end
+ * addresses and names.
+ *
+ * @param layout1 First layout to compare.
+ * @param layout2 Second layout to compare.
+ *
+ * @return 0 if layouts are identical,
+ *         1 if they differ or if either layout is NULL.
+ */
+int flashrom_layout_compare(const struct flashrom_layout *layout1,
+			    const struct flashrom_layout *layout2);
 /**
  * @brief Set the active layout for a flash context.
  *

libflashrom.c

@@ -458,12 +458,49 @@ bool flashrom_flag_get(const struct flashrom_flashctx *const flashctx, const enu
 #ifdef __FLASHROM_LITTLE_ENDIAN__
 static int compare_region_with_dump(const struct romentry *const a, const struct romentry *const b)
 {
-	if (a->region.start != b->region.end
+	if (a->region.start != b->region.start
 		|| a->region.end != b->region.end
 		|| strcmp(a->region.name, b->region.name))
 			return 1;
 	return 0;
 }
+
+int flashrom_layout_compare(const struct flashrom_layout *layout1,
+			    const struct flashrom_layout *layout2)
+{
+	if (!layout1 || !layout2) {
+		msg_gerr("Error: NULL layout pointer in comparison.\n");
+		return 1;
+	}
+
+	const struct romentry *entry1 = layout_next(layout1, NULL);
+	const struct romentry *entry2 = layout_next(layout2, NULL);
+
+	while (entry1 && entry2) {
+		if (compare_region_with_dump(entry1, entry2)) {
+			msg_gerr("Layout region mismatch:\n");
+			msg_gerr("  Region 1: '%s' [0x%08" PRIx32 ":0x%08" PRIx32 "]\n",
+				entry1->region.name, entry1->region.start, entry1->region.end);
+			msg_gerr("  Region 2: '%s' [0x%08" PRIx32 ":0x%08" PRIx32 "]\n",
+				entry2->region.name, entry2->region.start, entry2->region.end);
+			return 1;
+		}
+		entry1 = layout_next(layout1, entry1);
+		entry2 = layout_next(layout2, entry2);
+	}
+
+	/* If one layout has more regions than the other */
+	if (entry1 || entry2) {
+		msg_gerr("Layout region count mismatch.\n");
+		if (entry1)
+			msg_gerr("  Extra region in layout 1: '%s'\n", entry1->region.name);
+		if (entry2)
+			msg_gerr("  Extra region in layout 2: '%s'\n", entry2->region.name);
+		return 1;
+	}
+
+	return 0;
+}
 #endif /* __FLASHROM_LITTLE_ENDIAN__ */
 
 int flashrom_layout_read_from_ifd(struct flashrom_layout **const layout, struct flashctx *const flashctx,

libflashrom.map

@@ -13,6 +13,7 @@ LIBFLASHROM_1.0 {
     flashrom_image_write;
     flashrom_init;
     flashrom_layout_add_region;
+    flashrom_layout_compare;
     flashrom_layout_exclude_region;
     flashrom_layout_get_region_range;
     flashrom_layout_include_region;

tests/libflashrom.c

@@ -163,3 +163,60 @@ void probe_v2_error_code_propagation(void **state)
 #else
 	SKIP_TEST(probe_v2_error_code_propagation)
 #endif /* CONFIG_DUMMY */
+
+void flashrom_layout_compare_test_success(void **state)
+{
+	(void)state; /* unused */
+	struct flashrom_layout *layout1 = NULL;
+	struct flashrom_layout *layout2 = NULL;
+	struct flashrom_layout *layout3 = NULL;
+
+	/* Create three layouts */
+	assert_int_equal(0, flashrom_layout_new(&layout1));
+	assert_int_equal(0, flashrom_layout_new(&layout2));
+	assert_int_equal(0, flashrom_layout_new(&layout3));
+
+	/* Test 1: NULL pointer handling */
+	assert_int_not_equal(0, flashrom_layout_compare(NULL, layout1));
+	assert_int_not_equal(0, flashrom_layout_compare(layout1, NULL));
+	assert_int_not_equal(0, flashrom_layout_compare(NULL, NULL));
+
+	/* Test 2: Empty layouts should match */
+	assert_int_equal(0, flashrom_layout_compare(layout1, layout2));
+
+	/* Test 3: Add same regions to layout1 and layout2 */
+	assert_int_equal(0, flashrom_layout_add_region(layout1, 0x00000000, 0x000fffff, "REGION1"));
+	assert_int_equal(0, flashrom_layout_add_region(layout1, 0x00100000, 0x001fffff, "REGION2"));
+
+	assert_int_equal(0, flashrom_layout_add_region(layout2, 0x00000000, 0x000fffff, "REGION1"));
+	assert_int_equal(0, flashrom_layout_add_region(layout2, 0x00100000, 0x001fffff, "REGION2"));
+
+	/* Identical layouts should match */
+	assert_int_equal(0, flashrom_layout_compare(layout1, layout2));
+
+	/* Test 4: Add different region to layout3 */
+	assert_int_equal(0, flashrom_layout_add_region(layout3, 0x00000000, 0x000fffff, "REGION1"));
+	assert_int_equal(0, flashrom_layout_add_region(layout3, 0x00100000, 0x002fffff, "REGION2")); /* different end */
+
+	/* Different layouts should not match */
+	assert_int_not_equal(0, flashrom_layout_compare(layout1, layout3));
+
+	/* Test 5: Different number of regions */
+	flashrom_layout_release(layout3);
+	assert_int_equal(0, flashrom_layout_new(&layout3));
+	assert_int_equal(0, flashrom_layout_add_region(layout3, 0x00000000, 0x000fffff, "REGION1"));
+	/* layout3 has only 1 region, layout1 has 2 */
+	assert_int_not_equal(0, flashrom_layout_compare(layout1, layout3));
+
+	/* Test 6: Same regions but different names */
+	flashrom_layout_release(layout3);
+	assert_int_equal(0, flashrom_layout_new(&layout3));
+	assert_int_equal(0, flashrom_layout_add_region(layout3, 0x00000000, 0x000fffff, "DIFFERENT_NAME"));
+	assert_int_equal(0, flashrom_layout_add_region(layout3, 0x00100000, 0x001fffff, "REGION2"));
+	assert_int_not_equal(0, flashrom_layout_compare(layout1, layout3));
+
+	/* Cleanup */
+	flashrom_layout_release(layout1);
+	flashrom_layout_release(layout2);
+	flashrom_layout_release(layout3);
+}

tests/tests.c

@@ -476,6 +476,7 @@ int main(int argc, char *argv[])
 		cmocka_unit_test(flashrom_set_log_level_test_success),
 		cmocka_unit_test(flashrom_supported_programmers_test_success),
 		cmocka_unit_test(probe_v2_error_code_propagation),
+		cmocka_unit_test(flashrom_layout_compare_test_success),
 	};
 	ret |= cmocka_run_group_tests_name("libflashrom.c tests", libflashrom_tests, NULL, NULL);
 

tests/tests.h

@@ -29,6 +29,7 @@ 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);
 void probe_v2_error_code_propagation(void **state);
+void flashrom_layout_compare_test_success(void **state);
 
 /* spi25.c */
 void spi_write_enable_test_success(void **state);