Re: [PATCH v2 04/21] kconfig: reference environments directly and remove 'option env=' syntax

From: Ulf Magnusson
Date: Sat Mar 31 2018 - 22:27:38 EST


Here's a more in-depth review:

On Tue, Mar 27, 2018 at 7:29 AM, Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
> To get an environment value, Kconfig needs to define a symbol using
> "option env=" syntax. It is tedious to add a config entry for each
> environment given that we need more environments such as 'CC', 'AS',

"Environment variables" would be clearer. I've never seen them called
"environments".

> 'srctree' etc. to evaluate the compiler capability in Kconfig.
>
> Adding '$' to symbols is weird. Kconfig can reference symbols directly
> like this:
>
> config FOO
> string
> default BAR
>
> So, I want to use the following syntax to get environment 'BAR' from
> the system:
>
> config FOO
> string
> default $BAR
>
> Looking at the code, the symbols prefixed with 'S' are expanded by:
> - conf_expand_value()
> This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list'
> - expand_string_value()
> This is used to expand strings in 'source' and 'mainmenu'
>
> All of them are fixed values independent of user configuration. So,
> this kind of syntax should be moved to simply take the environment.
>
> This change makes the code much cleaner. The bounce symbols 'SRCARCH',
> 'ARCH', 'SUBARCH', 'KERNELVERSION' are gone.
>
> sym_init() hard-coding 'UNAME_RELEASE' is also gone. 'UNAME_RELEASE'
> should be be given from the environment.
>
> ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced
> by 'default ARCH_DEFCONFIG'.
>
> The environments are expanding in the lexer; when '$' is encountered,

s/environments/environment variables/

> it is expanded, and resulted strings are pushed back to the input
> stream. This makes the implementation simpler.
>
> For example, the following code works.
>
> [Example code]
>
> config TOOLCHAIN_LIST
> string
> default "My tools: CC=$CC, AS=$AS, CPP=$CPP"
>
> [Result]
>
> $ make -s alldefconfig && tail -n 1 .config
> CONFIG_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E"
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> ---
>
> I tested all 'make *config' for arch architectures.
> I confirmed this commit still produced the same result
> (by my kconfig test tool).
>
>
> Changes in v2:
> - Move the string expansion to the lexer phase.
> - Split environment helpers to env.c
>
> Documentation/kbuild/kconfig-language.txt | 8 ---
> Kconfig | 4 --
> Makefile | 3 +-
> arch/sh/Kconfig | 4 +-
> arch/sparc/Kconfig | 4 +-
> arch/tile/Kconfig | 2 +-
> arch/um/Kconfig.common | 4 --
> arch/x86/Kconfig | 4 +-
> arch/x86/um/Kconfig | 4 +-
> init/Kconfig | 10 +---
> scripts/kconfig/confdata.c | 31 +---------
> scripts/kconfig/env.c | 95 +++++++++++++++++++++++++++++++
> scripts/kconfig/kconf_id.c | 1 -
> scripts/kconfig/lkc.h | 8 +--
> scripts/kconfig/menu.c | 3 -
> scripts/kconfig/symbol.c | 56 ------------------
> scripts/kconfig/util.c | 75 ++++++++----------------
> scripts/kconfig/zconf.l | 20 ++++++-
> scripts/kconfig/zconf.y | 2 +-
> 19 files changed, 158 insertions(+), 180 deletions(-)
> create mode 100644 scripts/kconfig/env.c
>
> diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
> index f5b9493..0e966e8 100644
> --- a/Documentation/kbuild/kconfig-language.txt
> +++ b/Documentation/kbuild/kconfig-language.txt
> @@ -198,14 +198,6 @@ applicable everywhere (see syntax).
> enables the third modular state for all config symbols.
> At most one symbol may have the "modules" option set.
>
> - - "env"=<value>
> - This imports the environment variable into Kconfig. It behaves like
> - a default, except that the value comes from the environment, this
> - also means that the behaviour when mixing it with normal defaults is
> - undefined at this point. The symbol is currently not exported back
> - to the build environment (if this is desired, it can be done via
> - another symbol).
> -

The new behavior needs to be documented later as well (but iirc you
already mentioned that somewhere else).

> - "allnoconfig_y"
> This declares the symbol as one that should have the value y when
> using "allnoconfig". Used for symbols that hide other symbols.
> diff --git a/Kconfig b/Kconfig
> index 8c4c1cb..e6ece5b 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -5,8 +5,4 @@
> #
> mainmenu "Linux/$ARCH $KERNELVERSION Kernel Configuration"
>
> -config SRCARCH
> - string
> - option env="SRCARCH"
> -
> source "arch/$SRCARCH/Kconfig"
> diff --git a/Makefile b/Makefile
> index 5c395ed..4ae1486 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -284,7 +284,8 @@ include scripts/Kbuild.include
> # Read KERNELRELEASE from include/config/kernel.release (if it exists)
> KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
> KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
> -export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
> +UNAME_RELEASE := $(shell uname --release)
> +export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION UNAME_RELEASE
>
> # SUBARCH tells the usermode build what the underlying arch is. That is set
> # first, and if a usermode build is happening, the "ARCH=um" on the command
> diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
> index 97fe293..14f3ef1 100644
> --- a/arch/sh/Kconfig
> +++ b/arch/sh/Kconfig
> @@ -57,7 +57,7 @@ config SUPERH
> <http://www.linux-sh.org/>.
>
> config SUPERH32
> - def_bool ARCH = "sh"
> + def_bool "$ARCH" = "sh"
> select HAVE_KPROBES
> select HAVE_KRETPROBES
> select HAVE_IOREMAP_PROT if MMU && !X2TLB
> @@ -76,7 +76,7 @@ config SUPERH32
> select HAVE_CC_STACKPROTECTOR
>
> config SUPERH64
> - def_bool ARCH = "sh64"
> + def_bool "$ARCH" = "sh64"
> select HAVE_EXIT_THREAD
> select KALLSYMS
>
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index 8767e45..86b852e 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -1,6 +1,6 @@
> config 64BIT
> - bool "64-bit kernel" if ARCH = "sparc"
> - default ARCH = "sparc64"
> + bool "64-bit kernel" if "$ARCH" = "sparc"
> + default "$ARCH" = "sparc64"
> help
> SPARC is a family of RISC microprocessors designed and marketed by
> Sun Microsystems, incorporated. They are very widely found in Sun
> diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
> index ef9d403..acc2182 100644
> --- a/arch/tile/Kconfig
> +++ b/arch/tile/Kconfig
> @@ -119,7 +119,7 @@ config HVC_TILE
> # Building with ARCH=tilegx (or ARCH=tile) implies using the
> # 64-bit TILE-Gx toolchain, so force CONFIG_TILEGX on.
> config TILEGX
> - def_bool ARCH != "tilepro"
> + def_bool "$ARCH" != "tilepro"
> select ARCH_SUPPORTS_ATOMIC_RMW
> select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
> select HAVE_ARCH_JUMP_LABEL
> diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common
> index c68add8..07f84c8 100644
> --- a/arch/um/Kconfig.common
> +++ b/arch/um/Kconfig.common
> @@ -54,10 +54,6 @@ config HZ
> int
> default 100
>
> -config SUBARCH
> - string
> - option env="SUBARCH"
> -
> config NR_CPUS
> int
> range 1 1
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0fa71a7..986fb0a 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1,8 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> # Select 32 or 64 bit
> config 64BIT
> - bool "64-bit kernel" if ARCH = "x86"
> - default ARCH != "i386"
> + bool "64-bit kernel" if "$ARCH" = "x86"
> + default "$ARCH" != "i386"
> ---help---
> Say yes to build a 64-bit kernel - formerly known as x86_64
> Say no to build a 32-bit kernel - formerly known as i386
> diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
> index 13ed827..d355413 100644
> --- a/arch/x86/um/Kconfig
> +++ b/arch/x86/um/Kconfig
> @@ -16,8 +16,8 @@ config UML_X86
> select GENERIC_FIND_FIRST_BIT
>
> config 64BIT
> - bool "64-bit kernel" if SUBARCH = "x86"
> - default SUBARCH != "i386"
> + bool "64-bit kernel" if $SUBARCH = "x86"
> + default $SUBARCH != "i386"
>
> config X86_32
> def_bool !64BIT
> diff --git a/init/Kconfig b/init/Kconfig
> index df18492..b4814e6 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1,11 +1,3 @@
> -config ARCH
> - string
> - option env="ARCH"
> -
> -config KERNELVERSION
> - string
> - option env="KERNELVERSION"
> -
> config DEFCONFIG_LIST
> string
> depends on !UML
> @@ -13,7 +5,7 @@ config DEFCONFIG_LIST
> default "/lib/modules/$UNAME_RELEASE/.config"
> default "/etc/kernel-config"
> default "/boot/config-$UNAME_RELEASE"
> - default "$ARCH_DEFCONFIG"
> + default ARCH_DEFCONFIG
> default "arch/$ARCH/defconfig"
>
> config CONSTRUCTORS
> diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
> index df26c7b..98c2014 100644
> --- a/scripts/kconfig/confdata.c
> +++ b/scripts/kconfig/confdata.c
> @@ -81,39 +81,13 @@ const char *conf_get_autoconfig_name(void)
> return name ? name : "include/config/auto.conf";
> }
>
> -static char *conf_expand_value(const char *in)
> -{
> - struct symbol *sym;
> - const char *src;
> - static char res_value[SYMBOL_MAXLENGTH];
> - char *dst, name[SYMBOL_MAXLENGTH];
> -
> - res_value[0] = 0;
> - dst = name;
> - while ((src = strchr(in, '$'))) {
> - 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_value(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/env.c b/scripts/kconfig/env.c
> new file mode 100644
> index 0000000..9702f5c
> --- /dev/null
> +++ b/scripts/kconfig/env.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2018 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> +
> +static LIST_HEAD(env_list);
> +
> +struct env {
> + char *name;
> + char *value;
> + struct list_head node;
> +};
> +
> +static struct env *env_list_lookup(const char *name)
> +{
> + struct env *e;
> +
> + list_for_each_entry(e, &env_list, node) {
> + if (!strcmp(name, e->name))
> + return e;
> + }
> +
> + return NULL;
> +}

This function might be unnecessary -- see below.

> +
> +static void env_list_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_list_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)

This function is basically just getenv() with some dependency
housekeeping added. A name like env_get() or env_lookup() would be
clearer I think.

> +{
> + struct env *e;
> + const char *value;
> +

> + e = env_list_lookup(name);
> + if (e)
> + return xstrdup(e->value);

Not sure this bit is needed. It is always safe to get the value from
getenv(). See below.

> +
> + value = getenv(name);
> + if (!value) {
> + fprintf(stderr, "environment variable \"%s\" undefined\n", name);
> + value = "";
> + }
> +
> + /*
> + * we need to remember all referenced environments.

s/environments/environment variables/

> + * They will be written out to include/config/auto.conf.cmd
> + */
> + env_list_add(name, value);

AFAICS, we only need the following functionality:

1. Record referenced environment variables along with their value

2. Go through all the recorded environment variables and write
dependency information

For (1), I think it would be better to simply have env_list_add() (or
some other suitable name) add the variable to the list if it isn't
already there (like a kind of set). It is always safe to get the value
of the environment variable from getenv(), and that seems less
confusing.

> +
> + return xstrdup(value);

The returned string is never modified, and the result from getenv()
never gets stale, so I think the strdup() is unnecessary. The function
could return a const char * to avoid accidental modification.

> +}
> +
> +/* works like env_expand, but 'name' does not need to be null-terminated */
> +char *env_expand_n(const char *name, size_t n)

Could be renamed to something like env_get_n(), and could return a
const char * if the above modification is made.

> +{
> + char *tmp, *res;
> +
> + tmp = xmalloc(n + 1);
> + memcpy(tmp, name, n);
> + *(tmp + n) = '\0';
> +
> + res = env_expand(tmp);
> +
> + free(tmp);
> +
> + return res;
> +}
> +
> +void env_write_dep(FILE *f, const char *autoconfig_name)
> +{
> + struct env *env, *tmp;
> +
> + list_for_each_entry_safe(env, tmp, &env_list, node) {
> + fprintf(f, "ifneq \"$(%s)\" \"%s\"\n", env->name, env->value);
> + fprintf(f, "%s: FORCE\n", autoconfig_name);
> + fprintf(f, "endif\n");
> + env_list_del(env);
> + }
> +}
> diff --git a/scripts/kconfig/kconf_id.c b/scripts/kconfig/kconf_id.c
> index 3ea9c5f..b3e0ea0 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 c8d9e55..03d007f 100644
> --- a/scripts/kconfig/lkc.h
> +++ b/scripts/kconfig/lkc.h
> @@ -58,7 +58,6 @@ 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

Renumber to 3? Looks like a bitmask to me otherwise.

>
> struct kconf_id {
> @@ -95,6 +94,10 @@ static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out)
> fprintf(stderr, "Error in writing or end of file.\n");
> }
>
> +/* env.c */
> +char *env_expand_n(const char *name, size_t n);
> +void env_write_dep(FILE *f, const char *auto_conf_name);
> +
> /* menu.c */
> void _menu_init(void);
> void menu_warn(struct menu *menu, const char *fmt, ...);
> @@ -135,9 +138,6 @@ 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/menu.c b/scripts/kconfig/menu.c
> index 5c5c137..8148305 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/symbol.c b/scripts/kconfig/symbol.c
> index 03143b2..7c9a88e 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;
> @@ -1348,32 +1321,3 @@ 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 22201a4..136e497 100644
> --- a/scripts/kconfig/util.c
> +++ b/scripts/kconfig/util.c
> @@ -8,16 +8,18 @@
> #include <stdarg.h>
> #include <stdlib.h>
> #include <string.h>
> +
> +#include "list.h"
> #include "lkc.h"
>
> /*
> - * Expand symbol's names embedded in the string given in argument. Symbols'
> - * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
> + * Expand environments embedded in the string given in argument. Environments

s/environments/environment variables/

> + * to be expanded shall be prefixed by a '$'. Unknown environment expands to
> * the empty string.
> */
> char *expand_string_value(const char *in)
> {
> - const char *src;
> + const char *p, *q;
> char *res;
> size_t reslen;
>
> @@ -25,39 +27,28 @@ char *expand_string_value(const char *in)
> * Note: 'in' might come from a token that's about to be
> * freed, so make sure to always allocate a new string
> */
> - reslen = strlen(in) + 1;
> - res = xmalloc(reslen);
> - res[0] = '\0';
> -
> - while ((src = strchr(in, '$'))) {
> - char *p, name[SYMBOL_MAXLENGTH];
> - const char *symval = "";
> - struct symbol *sym;
> - size_t newlen;
> -
> - strncat(res, in, src - in);
> - src++;
> -
> - p = name;
> - while (isalnum(*src) || *src == '_')
> - *p++ = *src++;
> - *p = '\0';
> -
> - sym = sym_find(name);
> - if (sym != NULL) {
> - sym_calc_value(sym);
> - symval = sym_get_string_value(sym);
> - }
> + res = xmalloc(1);
> + *res = '\0';
>
> - newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
> - if (newlen > reslen) {
> - reslen = newlen;
> - res = xrealloc(res, reslen);
> - }
> + while ((p = strchr(in, '$'))) {
> + char *new;
> +
> + q = p + 1;
> + while (isalnum(*q) || *q == '_')
> + q++;
>
> - strcat(res, symval);
> - in = src;
> + new = env_expand_n(p + 1, q - p - 1);

'value' might be a clearer name than 'new'.

> +
> + reslen = strlen(res) + (p - in) + strlen(new) + 1;
> + res = xrealloc(res, reslen);
> + strncat(res, in, p - in);
> + strcat(res, new);
> + free(new);

Not needed it env_expand_n() (env_get_n()) is modified to return the
value from getenv() directly. 'new' is never modified either.

> + in = q;
> }
> +
> + reslen = strlen(res) + strlen(in) + 1;
> + res = xrealloc(res, reslen);
> strcat(res, in);
>
> return res;
> @@ -87,8 +78,6 @@ 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;
>
> @@ -107,21 +96,7 @@ 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$(deps_config): ;\n");
> fclose(out);
> diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
> index 045093d..551ca47 100644
> --- a/scripts/kconfig/zconf.l
> +++ b/scripts/kconfig/zconf.l
> @@ -35,6 +35,7 @@ struct buffer *current_buf;
>
> static int last_ts, first_ts;
>
> +static void expand_string(const char *in);
> static void zconf_endhelp(void);
> static void zconf_endfile(void);
>
> @@ -120,6 +121,7 @@ n [A-Za-z0-9_-]
> }
>
> <PARAM>{
> + "$".* expand_string(yytext);
> "&&" return T_AND;
> "||" return T_OR;
> "(" return T_OPEN_PAREN;
> @@ -157,12 +159,13 @@ n [A-Za-z0-9_-]
> }
>
> <STRING>{
> - [^'"\\\n]+/\n {
> + "$".* expand_string(yytext);
> + [^$'"\\\n]+/\n {
> append_string(yytext, yyleng);
> yylval.string = text;
> return T_WORD_QUOTE;
> }
> - [^'"\\\n]+ {
> + [^$'"\\\n]+ {
> append_string(yytext, yyleng);
> }
> \\.?/\n {
> @@ -249,6 +252,19 @@ n [A-Za-z0-9_-]
> }
>
> %%
> +static void expand_string(const char *in)
> +{
> + char *p, *q;
> +
> + p = expand_string_value(in);
> +
> + q = p + strlen(p);
> + while (q > p)
> + unput(*--q);
> +
> + free(p);
> +}

(In case any other reviewers jump in -- see earlier messages in this
thread for some gotchas related to this.)

> +
> void zconf_starthelp(void)
> {
> new_string();
> diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
> index 262c464..4ff4ac9 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"))
> @@ -775,6 +774,7 @@ void zconfdump(FILE *out)
> }
>
> #include "zconf.lex.c"
> +#include "env.c"
> #include "util.c"
> #include "confdata.c"
> #include "expr.c"
> --
> 2.7.4
>

Cheers,
Ulf