10 files changed, 326 insertions, 114 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 569217168e96..5f87ad561b08 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -30,7 +30,7 @@ static void conf_message(const char *fmt, ...)
 static const char *conf_filename;
 static int conf_lineno, conf_warnings;
 
-const char conf_defname[] = "arch/$ARCH/defconfig";
+const char conf_defname[] = "arch/$(ARCH)/defconfig";
 
 static void conf_warning(const char *fmt, ...)
 {
@@ -81,39 +81,13 @@ const char *conf_get_autoconfig_name(void)
         return name ? name : "include/config/auto.conf";
 }
 
-static char *conf_expand_value(const char *in)
-{
-        struct symbol *sym;
-        const char *src;
-        static char res_value[SYMBOL_MAXLENGTH];
-        char *dst, name[SYMBOL_MAXLENGTH];
-
-        res_value[0] = 0;
-        dst = name;
-        while ((src = strchr(in, '$'))) {
-                strncat(res_value, in, src - in);
-                src++;
-                dst = name;
-                while (isalnum(*src) || *src == '_')
-                        *dst++ = *src++;
-                *dst = 0;
-                sym = sym_lookup(name, 0);
-                sym_calc_value(sym);
-                strcat(res_value, sym_get_string_value(sym));
-                in = src;
-        }
-        strcat(res_value, in);
-
-        return res_value;
-}
-
 char *conf_get_default_confname(void)
 {
         struct stat buf;
         static char fullname[PATH_MAX+1];
         char *env, *name;
 
-        name = conf_expand_value(conf_defname);
+        name = expand_string(conf_defname);
         env = getenv(SRCTREE);
         if (env) {
                 sprintf(fullname, "%s/%s", env, name);
@@ -274,7 +248,8 @@ int conf_read_simple(const char *name, int def)
                         if (expr_calc_value(prop->visible.expr) == no ||
                             prop->expr->type != E_SYMBOL)
                                 continue;
-                        name = conf_expand_value(prop->expr->left.sym->name);
+                        sym_calc_value(prop->expr->left.sym);
+                        name = sym_get_string_value(prop->expr->left.sym);
                         in = zconf_fopen(name);
                         if (in) {
                                 conf_message("using defaults found in %s",
diff --git a/scripts/kconfig/kconf_id.c b/scripts/kconfig/kconf_id.c
index 3ea9c5f9f730..b3e0ea0ac732 100644
--- a/scripts/kconfig/kconf_id.c
+++ b/scripts/kconfig/kconf_id.c
@@ -32,7 +32,6 @@ static struct kconf_id kconf_id_array[] = {
         { "on",                 T_ON,                   TF_PARAM },
         { "modules",            T_OPT_MODULES,          TF_OPTION },
         { "defconfig_list",     T_OPT_DEFCONFIG_LIST,   TF_OPTION },
-        { "env",                T_OPT_ENV,              TF_OPTION },
         { "allnoconfig_y",      T_OPT_ALLNOCONFIG_Y,    TF_OPTION },
 };
 
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index 2628bc6a2141..ed3ff88e60ba 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -44,7 +44,6 @@ enum conf_def_mode {
 
 #define T_OPT_MODULES           1
 #define T_OPT_DEFCONFIG_LIST    2
-#define T_OPT_ENV               3
 #define T_OPT_ALLNOCONFIG_Y     4
 
 struct kconf_id {
@@ -103,6 +102,7 @@ void *xmalloc(size_t size);
 void *xcalloc(size_t nmemb, size_t size);
 void *xrealloc(void *p, size_t size);
 char *xstrdup(const char *s);
+char *xstrndup(const char *s, size_t n);
 
 struct gstr {
         size_t len;
@@ -120,9 +120,6 @@ void str_printf(struct gstr *gs, const char *fmt, ...);
 const char *str_get(struct gstr *gs);
 
 /* symbol.c */
-extern struct expr *sym_env_list;
-
-void sym_init(void);
 void sym_clear_all_valid(void);
 struct symbol *sym_choice_default(struct symbol *sym);
 const char *sym_get_string_default(struct symbol *sym);
diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 9dc8abfb1dc3..9f465fe1ca85 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -49,5 +49,11 @@ const char * sym_get_string_value(struct symbol *sym);
 
 const char * prop_get_type_name(enum prop_type type);
 
+/* preprocess.c */
+void env_write_dep(FILE *f, const char *auto_conf_name);
+char *expand_string(const char *in);
+char *expand_dollar(const char **str);
+char *expand_one_token(const char **str);
+
 /* expr.c */
 void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken);
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 068a4e4db20a..379a119dcd1e 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -214,9 +214,6 @@ void menu_add_option(int token, char *arg)
                         zconf_error("trying to redefine defconfig symbol");
                 sym_defconfig_list->flags |= SYMBOL_AUTO;
                 break;
-        case T_OPT_ENV:
-                prop_add_env(arg);
-                break;
         case T_OPT_ALLNOCONFIG_Y:
                 current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
                 break;
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
new file mode 100644
index 000000000000..a2eb2eb02929
--- /dev/null
+++ b/scripts/kconfig/preprocess.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2018 Masahiro Yamada <yamada.masahiro@socionext.com>
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "list.h"
+
+static void __attribute__((noreturn)) pperror(const char *format, ...)
+{
+        va_list ap;
+
+        fprintf(stderr, "%s:%d: ", current_file->name, yylineno);
+        va_start(ap, format);
+        vfprintf(stderr, format, ap);
+        va_end(ap);
+        fprintf(stderr, "\n");
+
+        exit(1);
+}
+
+/*
+ * Environment variables
+ */
+static LIST_HEAD(env_list);
+
+struct env {
+        char *name;
+        char *value;
+        struct list_head node;
+};
+
+static void env_add(const char *name, const char *value)
+{
+        struct env *e;
+
+        e = xmalloc(sizeof(*e));
+        e->name = xstrdup(name);
+        e->value = xstrdup(value);
+
+        list_add_tail(&e->node, &env_list);
+}
+
+static void env_del(struct env *e)
+{
+        list_del(&e->node);
+        free(e->name);
+        free(e->value);
+        free(e);
+}
+
+/* The returned pointer must be freed when done */
+static char *env_expand(const char *name)
+{
+        struct env *e;
+        const char *value;
+
+        if (!*name)
+                return NULL;
+
+        list_for_each_entry(e, &env_list, node) {
+                if (!strcmp(name, e->name))
+                        return xstrdup(e->value);
+        }
+
+        value = getenv(name);
+        if (!value)
+                return NULL;
+
+        /*
+         * We need to remember all referenced environment variables.
+         * They will be written out to include/config/auto.conf.cmd
+         */
+        env_add(name, value);
+
+        return xstrdup(value);
+}
+
+void env_write_dep(FILE *f, const char *autoconfig_name)
+{
+        struct env *e, *tmp;
+
+        list_for_each_entry_safe(e, tmp, &env_list, node) {
+                fprintf(f, "ifneq \"$(%s)\" \"%s\"\n", e->name, e->value);
+                fprintf(f, "%s: FORCE\n", autoconfig_name);
+                fprintf(f, "endif\n");
+                env_del(e);
+        }
+}
+
+static char *eval_clause(const char *str, size_t len)
+{
+        char *tmp, *name, *res;
+
+        tmp = xstrndup(str, len);
+
+        name = expand_string(tmp);
+
+        res = env_expand(name);
+        if (res)
+                goto free;
+
+        res = xstrdup("");
+free:
+        free(name);
+        free(tmp);
+
+        return res;
+}
+
+/*
+ * Expand a string that follows '$'
+ *
+ * For example, if the input string is
+ *     ($(FOO)$($(BAR)))$(BAZ)
+ * this helper evaluates
+ *     $($(FOO)$($(BAR)))
+ * and returns a new string containing the expansion (note that the string is
+ * recursively expanded), also advancing 'str' to point to the next character
+ * after the corresponding closing parenthesis, in this case, *str will be
+ *     $(BAR)
+ */
+char *expand_dollar(const char **str)
+{
+        const char *p = *str;
+        const char *q;
+        int nest = 0;
+
+        /*
+         * In Kconfig, variable references always start with "$(".
+         * Neither single-letter variables as in $A nor curly braces as in ${CC}
+         * are supported.  '$' not followed by '(' loses its special meaning.
+         */
+        if (*p != '(') {
+                *str = p;
+                return xstrdup("$");
+        }
+
+        p++;
+        q = p;
+        while (*q) {
+                if (*q == '(') {
+                        nest++;
+                } else if (*q == ')') {
+                        if (nest-- == 0)
+                                break;
+                }
+                q++;
+        }
+
+        if (!*q)
+                pperror("unterminated reference to '%s': missing ')'", p);
+
+        /* Advance 'str' to after the expanded initial portion of the string */
+        *str = q + 1;
+
+        return eval_clause(p, q - p);
+}
+
+static char *__expand_string(const char **str, bool (*is_end)(char c))
+{
+        const char *in, *p;
+        char *expansion, *out;
+        size_t in_len, out_len;
+
+        out = xmalloc(1);
+        *out = 0;
+        out_len = 1;
+
+        p = in = *str;
+
+        while (1) {
+                if (*p == '$') {
+                        in_len = p - in;
+                        p++;
+                        expansion = expand_dollar(&p);
+                        out_len += in_len + strlen(expansion);
+                        out = xrealloc(out, out_len);
+                        strncat(out, in, in_len);
+                        strcat(out, expansion);
+                        free(expansion);
+                        in = p;
+                        continue;
+                }
+
+                if (is_end(*p))
+                        break;
+
+                p++;
+        }
+
+        in_len = p - in;
+        out_len += in_len;
+        out = xrealloc(out, out_len);
+        strncat(out, in, in_len);
+
+        /* Advance 'str' to the end character */
+        *str = p;
+
+        return out;
+}
+
+static bool is_end_of_str(char c)
+{
+        return !c;
+}
+
+/*
+ * Expand variables in the given string.  Undefined variables
+ * expand to an empty string.
+ * The returned string must be freed when done.
+ */
+char *expand_string(const char *in)
+{
+        return __expand_string(&in, is_end_of_str);
+}
+
+static bool is_end_of_token(char c)
+{
+        /* Why are '.' and '/' valid characters for symbols? */
+        return !(isalnum(c) || c == '_' || c == '-' || c == '.' || c == '/');
+}
+
+/*
+ * Expand variables in a token.  The parsing stops when a token separater
+ * (in most cases, it is a whitespace) is encountered.  'str' is updated to
+ * point to the next character.
+ *
+ * The returned string must be freed when done.
+ */
+char *expand_one_token(const char **str)
+{
+        return __expand_string(str, is_end_of_token);
+}
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index f0b2e3b3102d..2460648a581a 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -33,33 +33,6 @@ struct symbol *sym_defconfig_list;
 struct symbol *modules_sym;
 tristate modules_val;
 
-struct expr *sym_env_list;
-
-static void sym_add_default(struct symbol *sym, const char *def)
-{
-        struct property *prop = prop_alloc(P_DEFAULT, sym);
-
-        prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
-}
-
-void sym_init(void)
-{
-        struct symbol *sym;
-        struct utsname uts;
-        static bool inited = false;
-
-        if (inited)
-                return;
-        inited = true;
-
-        uname(&uts);
-
-        sym = sym_lookup("UNAME_RELEASE", 0);
-        sym->type = S_STRING;
-        sym->flags |= SYMBOL_AUTO;
-        sym_add_default(sym, uts.release);
-}
-
 enum symbol_type sym_get_type(struct symbol *sym)
 {
         enum symbol_type type = sym->type;
@@ -1401,32 +1374,3 @@ const char *prop_get_type_name(enum prop_type type)
         }
         return "unknown";
 }
-
-static void prop_add_env(const char *env)
-{
-        struct symbol *sym, *sym2;
-        struct property *prop;
-        char *p;
-
-        sym = current_entry->sym;
-        sym->flags |= SYMBOL_AUTO;
-        for_all_properties(sym, prop, P_ENV) {
-                sym2 = prop_get_symbol(prop);
-                if (strcmp(sym2->name, env))
-                        menu_warn(current_entry, "redefining environment symbol from %s",
-                                  sym2->name);
-                return;
-        }
-
-        prop = prop_alloc(P_ENV, sym);
-        prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
-
-        sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
-        sym_env_list->right.sym = sym;
-
-        p = getenv(env);
-        if (p)
-                sym_add_default(sym, p);
-        else
-                menu_warn(current_entry, "environment variable %s undefined", env);
-}
diff --git a/scripts/kconfig/util.c b/scripts/kconfig/util.c
index c6f6e21b809f..703ee4904613 100644
--- a/scripts/kconfig/util.c
+++ b/scripts/kconfig/util.c
@@ -34,8 +34,6 @@ struct file *file_lookup(const char *name)
 /* write a dependency file as used by kbuild to track dependencies */
 int file_write_dep(const char *name)
 {
-        struct symbol *sym, *env_sym;
-        struct expr *e;
         struct file *file;
         FILE *out;
 
@@ -54,21 +52,7 @@ int file_write_dep(const char *name)
         fprintf(out, "\n%s: \\\n"
                      "\t$(deps_config)\n\n", conf_get_autoconfig_name());
 
-        expr_list_for_each_sym(sym_env_list, e, sym) {
-                struct property *prop;
-                const char *value;
-
-                prop = sym_get_env_prop(sym);
-                env_sym = prop_get_symbol(prop);
-                if (!env_sym)
-                        continue;
-                value = getenv(env_sym->name);
-                if (!value)
-                        value = "";
-                fprintf(out, "ifneq \"$(%s)\" \"%s\"\n", env_sym->name, value);
-                fprintf(out, "%s: FORCE\n", conf_get_autoconfig_name());
-                fprintf(out, "endif\n");
-        }
+        env_write_dep(out, conf_get_autoconfig_name());
 
         fprintf(out, "\n$(deps_config): ;\n");
         fclose(out);
@@ -165,3 +149,14 @@ char *xstrdup(const char *s)
         fprintf(stderr, "Out of memory.\n");
         exit(1);
 }
+
+char *xstrndup(const char *s, size_t n)
+{
+        char *p;
+
+        p = strndup(s, n);
+        if (p)
+                return p;
+        fprintf(stderr, "Out of memory.\n");
+        exit(1);
+}
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 045093d827e1..b3855909913c 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -1,6 +1,5 @@
 %option nostdinit noyywrap never-interactive full ecs
 %option 8bit nodefault yylineno
-%option noinput
 %x COMMAND HELP STRING PARAM
 %{
 /*
@@ -35,6 +34,8 @@ struct buffer *current_buf;
 
 static int last_ts, first_ts;
 
+static char *expand_token(const char *in, size_t n);
+static void append_expanded_string(const char *in);
 static void zconf_endhelp(void);
 static void zconf_endfile(void);
 
@@ -147,6 +148,13 @@ n	[A-Za-z0-9_-]
                 yylval.string = text;
                 return T_WORD;
         }
+        ({n}|[/.$])+    {
+                /* this token includes at least one '$' */
+                yylval.string = expand_token(yytext, yyleng);
+                if (strlen(yylval.string))
+                        return T_WORD;
+                free(yylval.string);
+        }
         #.*     /* comment */
         \\\n    ;
         [[:blank:]]+
@@ -157,12 +165,13 @@ n	[A-Za-z0-9_-]
 }
 
 <STRING>{
-        [^'"\\\n]+/\n   {
+        "$".*   append_expanded_string(yytext);
+        [^$'"\\\n]+/\n  {
                 append_string(yytext, yyleng);
                 yylval.string = text;
                 return T_WORD_QUOTE;
         }
-        [^'"\\\n]+      {
+        [^$'"\\\n]+     {
                 append_string(yytext, yyleng);
         }
         \\.?/\n {
@@ -249,6 +258,58 @@ n	[A-Za-z0-9_-]
 }
 
 %%
+static char *expand_token(const char *in, size_t n)
+{
+        char *out;
+        int c;
+        char c2;
+        const char *rest, *end;
+
+        new_string();
+        append_string(in, n);
+
+        /* get the whole line because we do not know the end of token. */
+        while ((c = input()) != EOF) {
+                if (c == '\n') {
+                        unput(c);
+                        break;
+                }
+                c2 = c;
+                append_string(&c2, 1);
+        }
+
+        rest = text;
+        out = expand_one_token(&rest);
+
+        /* push back unused characters to the input stream */
+        end = rest + strlen(rest);
+        while (end > rest)
+                unput(*--end);
+
+        free(text);
+
+        return out;
+}
+
+static void append_expanded_string(const char *str)
+{
+        const char *end;
+        char *res;
+
+        str++;
+
+        res = expand_dollar(&str);
+
+        /* push back unused characters to the input stream */
+        end = str + strlen(str);
+        while (end > str)
+                unput(*--end);
+
+        append_string(res, strlen(res));
+
+        free(res);
+}
+
 void zconf_starthelp(void)
 {
         new_string();
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index 8bfaaf853d23..031b2e24ae00 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -534,7 +534,6 @@ void conf_parse(const char *name)
 
         zconf_initscan(name);
 
-        sym_init();
         _menu_init();
 
         if (getenv("ZCONF_DEBUG"))
@@ -780,3 +779,4 @@ void zconfdump(FILE *out)
 #include "expr.c"
 #include "symbol.c"
 #include "menu.c"
+#include "preprocess.c"