kconfig: remove S_OTHER symbol type and correct dependency tracking

The S_OTHER type could be set only when conf_read_simple() is reading
include/config/auto.conf file.

For example, CONFIG_FOO=y exists in include/config/auto.conf but it is
missing from the currently parsed Kconfig files, sym_lookup() allocates
a new symbol, and sets its type to S_OTHER.

Strangely, it will be set to S_STRING by conf_set_sym_val() a few lines
below while it is obviously bool or tristate type. On the other hand,
when CONFIG_BAR="bar" is being dropped from include/config/auto.conf,
its type remains S_OTHER. Because for_all_symbols() omits S_OTHER
symbols, conf_touch_deps() misses to touch include/config/bar.h

This behavior has been a pretty mystery for me, and digging the git
histroy did not help. At least, touching depfiles is broken for string
type symbols.

I removed S_OTHER entirely, and reimplemented it more simply.

If CONFIG_FOO was visible in the previous syncconfig, but is missing
now, what we want to do is quite simple; just call conf_touch_dep()
to touch include/config/foo.h instead of allocating a new symbol data.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

3 files changed, 16 insertions, 24 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 39dfe463de15..9ef135735cfa 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -227,14 +227,6 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
                         conf_warning("symbol value '%s' invalid for %s",
                                      p, sym->name);
                 return 1;
-        case S_OTHER:
-                if (*p != '"') {
-                        for (p2 = p; *p2 && !isspace(*p2); p2++)
-                                ;
-                        sym->type = S_STRING;
-                        goto done;
-                }
-                /* fall through */
         case S_STRING:
                 if (*p++ != '"')
                         break;
@@ -253,7 +245,6 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
                 /* fall through */
         case S_INT:
         case S_HEX:
-        done:
                 if (sym_string_valid(sym, p)) {
                         sym->def[def].val = xstrdup(p);
                         sym->flags |= def_flags;
@@ -434,17 +425,22 @@ load:
                                 if (*p2 == '\r')
                                         *p2 = 0;
                         }
-                        if (def == S_DEF_USER) {
-                                sym = sym_find(line + strlen(CONFIG_));
-                                if (!sym) {
+
+                        sym = sym_find(line + strlen(CONFIG_));
+                        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.h must be touched.
+                                         */
+                                        conf_touch_dep(line + strlen(CONFIG_));
+                                else
                                         sym_add_change_count(1);
-                                        continue;
-                                }
-                        } else {
-                                sym = sym_lookup(line + strlen(CONFIG_), 0);
-                                if (sym->type == S_UNKNOWN)
-                                        sym->type = S_OTHER;
+                                continue;
                         }
+
                         if (sym->flags & def_flags) {
                                 conf_warning("override: reassigning to symbol %s", sym->name);
                         }
@@ -710,7 +706,6 @@ static void conf_write_symbol(FILE *fp, struct symbol *sym,
         const char *str;
 
         switch (sym->type) {
-        case S_OTHER:
         case S_UNKNOWN:
                 break;
         case S_STRING:
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
index 7c329e179007..2b7e222b0784 100644
--- a/scripts/kconfig/expr.h
+++ b/scripts/kconfig/expr.h
@@ -62,7 +62,7 @@ struct symbol_value {
 };
 
 enum symbol_type {
-        S_UNKNOWN, S_BOOLEAN, S_TRISTATE, S_INT, S_HEX, S_STRING, S_OTHER
+        S_UNKNOWN, S_BOOLEAN, S_TRISTATE, S_INT, S_HEX, S_STRING
 };
 
 /* enum values are used as index to symbol.def[] */
@@ -131,7 +131,7 @@ struct symbol {
         struct expr_value implied;
 };
 
-#define for_all_symbols(i, sym) for (i = 0; i < SYMBOL_HASHSIZE; i++) for (sym = symbol_hash[i]; sym; sym = sym->next) if (sym->type != S_OTHER)
+#define for_all_symbols(i, sym) for (i = 0; i < SYMBOL_HASHSIZE; i++) for (sym = symbol_hash[i]; sym; sym = sym->next)
 
 #define SYMBOL_CONST      0x0001  /* symbol is const */
 #define SYMBOL_CHECK      0x0008  /* used during dependency checking */
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 703b9b899ee9..2e6bf362d164 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -61,8 +61,6 @@ const char *sym_type_name(enum symbol_type type)
                 return "string";
         case S_UNKNOWN:
                 return "unknown";
-        case S_OTHER:
-                break;
         }
         return "???";
 }
@@ -757,7 +755,6 @@ const char *sym_get_string_default(struct symbol *sym)
                 return str;
         case S_STRING:
                 return str;
-        case S_OTHER:
         case S_UNKNOWN:
                 break;
         }