[PATCHv2 -next] kconfig: add dependency warning print about invalid values in verbose mode

[sunying@nj.iscas.ac.cn]

From: Ying Sun <sunying@nj.iscas.ac.cn>

Add warning about the configuration option's invalid value in verbose mode,
 including error causes, mismatch dependency, old and new values,
 to help users correct them.

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

Signed-off-by: Siyuan Guo <zy21df106@buaa.edu.cn>
Signed-off-by: Ying Sun <sunying@nj.iscas.ac.cn>
---
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 | 100 +++++++++++++++++++++++++++++++++++--
 scripts/kconfig/lkc.h      |   7 +++
 scripts/kconfig/symbol.c   |  24 +++++++--
 3 files changed, 121 insertions(+), 10 deletions(-)

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 4a6811d77d18..86794ab39d7d 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -154,6 +154,56 @@ static void conf_message(const char *fmt, ...)
 
 static const char *conf_filename;
 static int conf_lineno, conf_warnings;
+const char *verbose;
+
+void conf_error_log(enum error_type type, struct symbol *sym, char *log, ...)
+{
+	static char *const tristate2str[3] = {"n", "m", "y"};
+	struct gstr gs = str_new();
+	char s[100];
+	char *oldval = NULL;
+	va_list args;
+
+	va_start(args, log);
+	vsnprintf(s, sizeof(s), log, args);
+	va_end(args);
+
+	switch (sym->type) {
+	case S_BOOLEAN:
+	case S_TRISTATE:
+		oldval = tristate2str[sym->def[S_DEF_USER].tri];
+		break;
+	case S_INT:
+	case S_HEX:
+	case S_STRING:
+		oldval = sym->def[S_DEF_USER].val;
+	default:
+		break;
+	}
+
+	str_printf(&gs,
+		"\nWARNING : %s [%s] value is invalid\n",
+		sym->name, oldval);
+	str_printf(&gs, s);
+	switch (type) {
+	case DIR_DEP:
+		str_printf(&gs,
+			"  Depends on [%c]: ",
+			sym->dir_dep.tri == mod ? 'm' : 'n');
+		expr_gstr_print(sym->dir_dep.expr, &gs);
+		str_printf(&gs, "\n");
+		break;
+	case REV_DEP:
+		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");
+		break;
+	default:
+		break;
+	}
+	fputs(str_get(&gs), stderr);
+}
 
 static void conf_warning(const char *fmt, ...)
 {
@@ -226,11 +276,14 @@ static const char *conf_get_rustccfg_name(void)
 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 {
 	char *p2;
+	static const char * const type[] = {"unknown", "bool", "tristate", "int", "hex", "string"};
 
 	switch (sym->type) {
 	case S_TRISTATE:
 		if (p[0] == 'm') {
 			sym->def[def].tri = mod;
+
+
 			sym->flags |= def_flags;
 			break;
 		}
@@ -246,9 +299,14 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 			sym->flags |= def_flags;
 			break;
 		}
-		if (def != S_DEF_AUTO)
-			conf_warning("symbol value '%s' invalid for %s",
+		if (def != S_DEF_AUTO) {
+			if (verbose)
+				conf_warning("symbol value '%s' invalid for %s\n due to its type is %s",
+				     p, sym->name, type[sym->type]);
+			else
+				conf_warning("symbol value '%s' invalid for %s",
 				     p, sym->name);
+		}
 		return 1;
 	case S_STRING:
 		/* No escaping for S_DEF_AUTO (include/config/auto.conf) */
@@ -274,9 +332,14 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 			sym->def[def].val = xstrdup(p);
 			sym->flags |= def_flags;
 		} else {
-			if (def != S_DEF_AUTO)
-				conf_warning("symbol value '%s' invalid for %s",
-					     p, sym->name);
+			if (def != S_DEF_AUTO) {
+				if (verbose)
+					conf_warning("symbol value '%s' invalid for %s\n due to its type is %s",
+						p, sym->name, type[sym->type]);
+				else
+					conf_warning("symbol value '%s' invalid for %s",
+						p, sym->name);
+			}
 			return 1;
 		}
 		break;
@@ -545,6 +608,7 @@ int conf_read(const char *name)
 	int conf_unsaved = 0;
 	int i;
 
+	verbose = getenv("KCONFIG_VERBOSE");
 	conf_set_changed(false);
 
 	if (conf_read_simple(name, S_DEF_USER)) {
@@ -576,6 +640,32 @@ int conf_read(const char *name)
 			continue;
 		conf_unsaved++;
 		/* maybe print value in verbose mode... */
+		if (verbose) {
+			switch (sym->type) {
+			case S_BOOLEAN:
+			case S_TRISTATE:
+				if (sym->def[S_DEF_USER].tri != sym->curr.tri) {
+					if (sym->dir_dep.tri < sym->def[S_DEF_USER].tri)
+						conf_error_log(DIR_DEP, sym,
+							"  due to unmet direct dependencies\n",
+							NULL);
+					if (sym->rev_dep.tri > sym->def[S_DEF_USER].tri)
+						conf_error_log(REV_DEP, sym,
+							"  due to it is selected\n", NULL);
+				}
+				break;
+			case S_INT:
+			case S_HEX:
+			case S_STRING:
+				if (sym->dir_dep.tri == no &&
+					strcmp((char *)(sym->def[S_DEF_USER].val), "") != 0)
+					conf_error_log(DIR_DEP, sym,
+						"  due to unmet direct dependencies\n", NULL);
+				break;
+			default:
+				break;
+			}
+		}
 	}
 
 	for_all_symbols(i, sym) {
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index 471a59acecec..242b24650f47 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -38,10 +38,17 @@ void zconf_initscan(const char *name);
 void zconf_nextfile(const char *name);
 int zconf_lineno(void);
 const char *zconf_curname(void);
+extern const char *verbose;
+enum error_type {
+	DIR_DEP,
+	REV_DEP,
+	RANGE
+};
 
 /* confdata.c */
 const char *conf_get_configname(void);
 void set_all_choice_values(struct symbol *csym);
+void conf_error_log(enum error_type type, struct symbol *sym, char *log, ...);
 
 /* confdata.c and expr.c */
 static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out)
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 0572330bf8a7..a78f7eb64f40 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -600,7 +600,7 @@ bool sym_string_valid(struct symbol *sym, const char *str)
 bool sym_string_within_range(struct symbol *sym, const char *str)
 {
 	struct property *prop;
-	long long val;
+	long long val, left, right;
 
 	switch (sym->type) {
 	case S_STRING:
@@ -612,8 +612,15 @@ bool sym_string_within_range(struct symbol *sym, const char *str)
 		if (!prop)
 			return true;
 		val = strtoll(str, NULL, 10);
-		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
-		       val <= sym_get_range_val(prop->expr->right.sym, 10);
+		left = sym_get_range_val(prop->expr->left.sym, 10);
+		right = sym_get_range_val(prop->expr->right.sym, 10);
+		if (val >= left && val <= right)
+			return true;
+		if (verbose)
+			conf_error_log(RANGE, sym,
+				"  symbol value is %lld, the range is (%lld %lld)\n",
+				val, left, right);
+		return false;
 	case S_HEX:
 		if (!sym_string_valid(sym, str))
 			return false;
@@ -621,8 +628,15 @@ bool sym_string_within_range(struct symbol *sym, const char *str)
 		if (!prop)
 			return true;
 		val = strtoll(str, NULL, 16);
-		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
-		       val <= sym_get_range_val(prop->expr->right.sym, 16);
+		left = sym_get_range_val(prop->expr->left.sym, 16);
+		right = sym_get_range_val(prop->expr->right.sym, 16);
+		if (val >= left && val <= right)
+			return true;
+		if (verbose)
+			conf_error_log(RANGE, sym,
+				"  symbol value is 0x%llx, the range is (0x%llx 0x%llx)\n",
+				val, left, right);
+		return false;
 	case S_BOOLEAN:
 	case S_TRISTATE:
 		switch (str[0]) {
-- 
2.17.1