kconfig: deduplicate code in conf_read_simple()

Kconfig accepts both "# CONFIG_FOO is not set" and "CONFIG_FOO=n" as
a valid input, but conf_read_simple() duplicates similar code to handle
them. Factor out the common code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/confdata.c

@@ -342,11 +342,10 @@ int conf_read_simple(const char *name, int def)
 	FILE *in = NULL;
 	char   *line = NULL;
 	size_t  line_asize = 0;
-	char *p, *p2;
+	char *p, *p2, *val;
 	struct symbol *sym;
 	int i, def_flags;
-	const char *warn_unknown;
-	const char *werror;
+	const char *warn_unknown, *werror, *sym_name;
 
 	warn_unknown = getenv("KCONFIG_WARN_UNKNOWN_SYMBOLS");
 	werror = getenv("KCONFIG_WERROR");
@@ -424,84 +423,66 @@ int conf_read_simple(const char *name, int def)
 
 	while (compat_getline(&line, &line_asize, in) != -1) {
 		conf_lineno++;
-		sym = NULL;
 		if (line[0] == '#') {
 			if (line[1] != ' ')
 				continue;
-			if (memcmp(line + 2, CONFIG_, strlen(CONFIG_)))
+			p = line + 2;
+			if (memcmp(p, CONFIG_, strlen(CONFIG_)))
 				continue;
-			p = strchr(line + 2 + strlen(CONFIG_), ' ');
+			sym_name = p + strlen(CONFIG_);
+			p = strchr(sym_name, ' ');
 			if (!p)
 				continue;
 			*p++ = 0;
 			if (strncmp(p, "is not set", 10))
 				continue;
 
-			sym = sym_find(line + 2 + strlen(CONFIG_));
-			if (!sym) {
-				if (warn_unknown)
-					conf_warning("unknown symbol: %s",
-						     line + 2 + strlen(CONFIG_));
-
-				conf_set_changed(true);
-				continue;
-			}
-			if (sym->flags & def_flags) {
-				conf_warning("override: reassigning to symbol %s", sym->name);
-			}
-			switch (sym->type) {
-			case S_BOOLEAN:
-			case S_TRISTATE:
-				sym->def[def].tri = no;
-				sym->flags |= def_flags;
-				break;
-			default:
-				;
-			}
+			val = "n";
 		} else if (memcmp(line, CONFIG_, strlen(CONFIG_)) == 0) {
-			p = strchr(line + strlen(CONFIG_), '=');
+			sym_name = line + strlen(CONFIG_);
+			p = strchr(sym_name, '=');
 			if (!p)
 				continue;
 			*p++ = 0;
+			val = p;
 			p2 = strchr(p, '\n');
 			if (p2) {
 				*p2-- = 0;
 				if (*p2 == '\r')
 					*p2 = 0;
 			}
+		} else {
+			if (line[0] != '\r' && line[0] != '\n')
+				conf_warning("unexpected data: %.*s",
+					     (int)strcspn(line, "\r\n"), line);
+
+			continue;
+		}
 
-			sym = sym_find(line + strlen(CONFIG_));
+		sym = sym_find(sym_name);
 		if (!sym) {
 			if (def == S_DEF_AUTO) {
 				/*
-					 * Reading from include/config/auto.conf
-					 * If CONFIG_FOO previously existed in
-					 * auto.conf but it is missing now,
-					 * include/config/FOO must be touched.
+				 * Reading from include/config/auto.conf.
+				 * If CONFIG_FOO previously existed in auto.conf
+				 * but it is missing now, include/config/FOO
+				 * must be touched.
 				 */
-					conf_touch_dep(line + strlen(CONFIG_));
+				conf_touch_dep(sym_name);
 			} else {
 				if (warn_unknown)
-						conf_warning("unknown symbol: %s",
-							     line + strlen(CONFIG_));
+					conf_warning("unknown symbol: %s", sym_name);
 
 				conf_set_changed(true);
 			}
 			continue;
 		}
 
-			if (sym->flags & def_flags) {
+		if (sym->flags & def_flags)
 			conf_warning("override: reassigning to symbol %s", sym->name);
-			}
-			if (conf_set_sym_val(sym, def, def_flags, p))
-				continue;
-		} else {
-			if (line[0] != '\r' && line[0] != '\n')
-				conf_warning("unexpected data: %.*s",
-					     (int)strcspn(line, "\r\n"), line);
 
+		if (conf_set_sym_val(sym, def, def_flags, val))
 			continue;
-		}
 
 		if (sym && sym_is_choice_value(sym)) {
 			struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));