[PATCH v2 1/2] kconfig: add prop_err function to simplify property error handling

[Julian Braha <julianbraha@gmail.com>]

As suggested by Nicolas while reviewing another Kconfig property error [1],
we can add a prop_err() function to simplify the tracking and display of
Kconfig property errors.

Note that the formatting of the warning printing is changed slightly
(adding a space) to better match the formatting used by gcc. This causes
a change to the expected test output for the existing warnings that call
prop_warn() and menu_warn().

Link: https://lore.kernel.org/all/20260917-proficient-swift-of-masquerade-0ff7ce@l-nschier-aarch64/ [1]
Assisted-by: LLM
Suggested-by: Nicolas Schier <n.schier@fritz.com>
Signed-off-by: Julian Braha <julianbraha@gmail.com>
---
Changes since v1:
- adjust warning and error printing to match gcc (Nicolas)

Link to v1:
https://lore.kernel.org/linux-kbuild/20260922163749.2031594-1-julianbraha@gmail.com/
---
 scripts/kconfig/menu.c                        | 27 ++++++++++++-------
 .../tests/err_transitional/expected_stderr    |  2 +-
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index bda3e2650216..db5ba57125c5 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -43,7 +43,7 @@ void menu_warn(const struct menu *menu, const char *fmt, ...)
 {
 	va_list ap;
 	va_start(ap, fmt);
-	fprintf(stderr, "%s:%d:warning: ", menu->filename, menu->lineno);
+	fprintf(stderr, "%s:%d: warning: ", menu->filename, menu->lineno);
 	vfprintf(stderr, fmt, ap);
 	fprintf(stderr, "\n");
 	va_end(ap);
@@ -53,7 +53,17 @@ static void prop_warn(const struct property *prop, const char *fmt, ...)
 {
 	va_list ap;
 	va_start(ap, fmt);
-	fprintf(stderr, "%s:%d:warning: ", prop->filename, prop->lineno);
+	fprintf(stderr, "%s:%d: warning: ", prop->filename, prop->lineno);
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+	va_end(ap);
+}
+
+static void prop_err(const struct property *prop, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	fprintf(stderr, "%s:%d: error: ", prop->filename, prop->lineno);
 	vfprintf(stderr, fmt, ap);
 	fprintf(stderr, "\n");
 	va_end(ap);
@@ -246,18 +256,15 @@ static int menu_validate_number(struct symbol *sym, struct symbol *sym2,
 
 	if (sym2->type != S_UNKNOWN ||
 		!sym_string_valid(sym, sym2->name)) {
-		fprintf(stderr, "%s:%d: error: '%s' is an invalid value for '%s'\n",
-			prop->filename, prop->lineno, sym2->name,
-			sym_type_name(sym->type));
+		prop_err(prop, "'%s' is an invalid value for '%s'",
+			 sym2->name, sym_type_name(sym->type));
 		return 1;
 	}
 
 	if (!sym_string_check_bounds(sym, sym2->name)) {
-		fprintf(stderr,
-			"%s:%d: error: %s constant '%s' is outside the 64-bit %s bounds\n",
-			prop->filename, prop->lineno, sym_type_name(sym->type),
-			sym2->name, sym->type == S_INT ? "signed" : "unsigned");
-
+		prop_err(prop, "%s constant '%s' is outside the 64-bit %s bounds",
+			 sym_type_name(sym->type), sym2->name,
+			 sym->type == S_INT ? "signed" : "unsigned");
 		return 1;
 	}
 
diff --git a/scripts/kconfig/tests/err_transitional/expected_stderr b/scripts/kconfig/tests/err_transitional/expected_stderr
index b52db4f680f4..ba317850c043 100644
--- a/scripts/kconfig/tests/err_transitional/expected_stderr
+++ b/scripts/kconfig/tests/err_transitional/expected_stderr
@@ -1,4 +1,4 @@
-Kconfig:46:warning: config symbol defined without type
+Kconfig:46: warning: config symbol defined without type
 Kconfig:7: error: transitional symbols can only have help sections
 Kconfig:14: error: transitional symbols can only have help sections
 Kconfig:21: error: transitional symbols can only have help sections
-- 
2.55.0