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From: sunying@isrc.iscas.ac.cn
To: masahiroy@kernel.org
Cc: linux-kbuild@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	pengpeng@iscas.ac.cn,
	Ying Sun <sunying@isrc.iscas.ac.cn>,
	Siyuan Guo <zy21df106@buaa.edu.cn>
Subject: [PATCHv3 next] kconfig: add dependency warning print about invalid values in verbose mode
Date: Tue,  2 Jan 2024 10:04:05 +0800
Message-ID: <20240102020405.32701-1-sunying@isrc.iscas.ac.cn>
Precedence: bulk
MIME-Version: 1.0
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From: Ying Sun <sunying@isrc.iscas.ac.cn>

Warning in verbose mode about incorrect causes and
 mismatch dependency of invalid values to help users correct them.

Detailed warning messages are printed only when the environment variable
 is set like "KCONFIG_WARN_CHANGED_INPUT=1".
By default, the current behavior is not changed.

Signed-off-by: Siyuan Guo <zy21df106@buaa.edu.cn>
Signed-off-by: Ying Sun <sunying@isrc.iscas.ac.cn>
---
v2 -> v3:
* Fixed warning message that mess up the ncurses display.
* Fixed memory leak where str_new() was called but str_free() was not used.
* Integrated the code to avoid excessive dispersion.
* Use the environment variable KCONFIG_WARN_CHANGED_INPUT as the switch

v1 -> v2:
* Reduced the number of code lines by refactoring and simplifying the logic.
* Changed the print "ERROR" to "WARNING".
* Focused on handling dependency errors: dir_dep and rev_dep, and range error.
  - A downgrade from 'y' to 'm' has be warned.
  - A new CONFIG option should not be warned.
  - Overwriting caused by default value is not an error and is no longer printed.
* Fixed style issues.
---
---
 scripts/kconfig/confdata.c | 76 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index f1197e672431..352774928558 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -195,6 +195,52 @@ static void conf_message(const char *fmt, ...)
 	va_end(ap);
 }
 
+static void conf_warn_unmet_rev_dep(struct symbol *sym)
+{
+	struct gstr gs = str_new();
+	char value = 'n';
+
+	switch (sym->curr.tri) {
+	case no:
+		value = 'n';
+		break;
+	case mod:
+		sym_calc_value(modules_sym);
+		value = (modules_sym->curr.tri == no) ? 'n' : 'm';
+		break;
+	case yes:
+		value = 'y';
+	}
+
+	str_printf(&gs,
+		"'%s' set to %c for it is selected\n",
+		sym->name, value);
+	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
+				" Selected by [y]:\n");
+	expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
+				" Selected by [m]:\n");
+
+	conf_warning("%s", str_get(&gs));
+	str_free(&gs);
+}
+
+static void conf_warn_dep_error(struct symbol *sym)
+{
+	struct gstr gs = str_new();
+
+	str_printf(&gs,
+		"'%s' set to n for it unmet direct dependencies\n",
+		sym->name);
+
+	str_printf(&gs,
+		" Depends on [%c]: ",
+		sym->dir_dep.tri == mod ? 'm' : 'n');
+	expr_gstr_print(sym->dir_dep.expr, &gs);
+
+	conf_warning("%s\n", str_get(&gs));
+	str_free(&gs);
+}
+
 const char *conf_get_configname(void)
 {
 	char *name = getenv("KCONFIG_CONFIG");
@@ -568,6 +614,36 @@ int conf_read(const char *name)
 			continue;
 		conf_unsaved++;
 		/* maybe print value in verbose mode... */
+		if (getenv("KCONFIG_WARN_CHANGED_INPUT") && (sym->prop)) {
+			conf_filename = sym->prop->file->name;
+			conf_lineno = sym->prop->menu->lineno;
+
+			switch (sym->type) {
+			case S_BOOLEAN:
+			case S_TRISTATE:
+				if (sym->def[S_DEF_USER].tri != sym_get_tristate_value(sym)) {
+					if (sym->dir_dep.tri < sym->def[S_DEF_USER].tri)
+						conf_warn_dep_error(sym);
+					else if (sym->rev_dep.tri > sym->def[S_DEF_USER].tri)
+						conf_warn_unmet_rev_dep(sym);
+					else
+						conf_warning("'%s' set to %s due to option constraints\n",
+							sym->name, sym_get_string_value(sym));
+				}
+				break;
+			case S_INT:
+			case S_HEX:
+			case S_STRING:
+				if (sym->dir_dep.tri == no && sym_has_value(sym))
+					conf_warn_dep_error(sym);
+				else
+					conf_warning("'%s' set to %s due to option constraints\n",
+							sym->name, sym_get_string_value(sym));
+				break;
+			default:
+				break;
+			}
+		}
 	}
 
 	for_all_symbols(i, sym) {
-- 
2.43.0