kconfig: integrate split config into silentoldconfig

Now that kconfig can load multiple configurations, it becomes simple to
integrate the split config step, by simply comparing the new .config file with
the old auto.conf (and then saving the new auto.conf).  A nice side effect is
that this saves a bit of disk space and cache, as no data needs to be read
from or saved into the splitted config files anymore (e.g.  include/config is
now 648KB instead of 5.2MB).

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

4 files changed, 123 insertions, 233 deletions

diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile
index f22e94c3a2d..2f60070f973 100644
--- a/scripts/basic/Makefile
+++ b/scripts/basic/Makefile
@@ -1,17 +1,15 @@
 ###
 # Makefile.basic list the most basic programs used during the build process.
 # The programs listed herein is what is needed to do the basic stuff,
-# such as splitting .config and fix dependency file.
+# such as fix dependency file.
 # This initial step is needed to avoid files to be recompiled
 # when kernel configuration changes (which is what happens when
 # .config is included by main Makefile.
 # ---------------------------------------------------------------------------
 # fixdep: 	 Used to generate dependency information during build process
-# split-include: Divide all config symbols up in a number of files in
-#                include/config/...
 # docproc:	 Used in Documentation/docbook
 
-hostprogs-y	:= fixdep split-include docproc
+hostprogs-y	:= fixdep docproc
 always		:= $(hostprogs-y)
 
 # fixdep is needed to compile other host programs
diff --git a/scripts/basic/split-include.c b/scripts/basic/split-include.c
deleted file mode 100644
index 459c45276cb..00000000000
--- a/scripts/basic/split-include.c
+++ /dev/null
@@ -1,226 +0,0 @@
-/*
- * split-include.c
- *
- * Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
- * This is a C version of syncdep.pl by Werner Almesberger.
- *
- * This program takes autoconf.h as input and outputs a directory full
- * of one-line include files, merging onto the old values.
- *
- * Think of the configuration options as key-value pairs.  Then there
- * are five cases:
- *
- *    key      old value   new value   action
- *
- *    KEY-1    VALUE-1     VALUE-1     leave file alone
- *    KEY-2    VALUE-2A    VALUE-2B    write VALUE-2B into file
- *    KEY-3    -           VALUE-3     write VALUE-3  into file
- *    KEY-4    VALUE-4     -           write an empty file
- *    KEY-5    (empty)     -           leave old empty file alone
- */
-
-#include <sys/stat.h>
-#include <sys/types.h>
-
-#include <ctype.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#define ERROR_EXIT(strExit)						\
-    {									\
-	const int errnoSave = errno;					\
-	fprintf(stderr, "%s: ", str_my_name);				\
-	errno = errnoSave;						\
-	perror((strExit));						\
-	exit(1);							\
-    }
-
-
-
-int main(int argc, const char * argv [])
-{
-    const char * str_my_name;
-    const char * str_file_autoconf;
-    const char * str_dir_config;
-
-    FILE * fp_config;
-    FILE * fp_target;
-    FILE * fp_find;
-
-    int buffer_size;
-
-    char * line;
-    char * old_line;
-    char * list_target;
-    char * ptarget;
-
-    struct stat stat_buf;
-
-    /* Check arg count. */
-    if (argc != 3)
-    {
-	fprintf(stderr, "%s: wrong number of arguments.\n", argv[0]);
-	exit(1);
-    }
-
-    str_my_name       = argv[0];
-    str_file_autoconf = argv[1];
-    str_dir_config    = argv[2];
-
-    /* Find a buffer size. */
-    if (stat(str_file_autoconf, &stat_buf) != 0)
-	ERROR_EXIT(str_file_autoconf);
-    buffer_size = 2 * stat_buf.st_size + 4096;
-
-    /* Allocate buffers. */
-    if ( (line        = malloc(buffer_size)) == NULL
-    ||   (old_line    = malloc(buffer_size)) == NULL
-    ||   (list_target = malloc(buffer_size)) == NULL )
-	ERROR_EXIT(str_file_autoconf);
-
-    /* Open autoconfig file. */
-    if ((fp_config = fopen(str_file_autoconf, "r")) == NULL)
-	ERROR_EXIT(str_file_autoconf);
-
-    /* Make output directory if needed. */
-    if (stat(str_dir_config, &stat_buf) != 0)
-    {
-	if (mkdir(str_dir_config, 0755) != 0)
-	    ERROR_EXIT(str_dir_config);
-    }
-
-    /* Change to output directory. */
-    if (chdir(str_dir_config) != 0)
-	ERROR_EXIT(str_dir_config);
-
-    /* Put initial separator into target list. */
-    ptarget = list_target;
-    *ptarget++ = '\n';
-
-    /* Read config lines. */
-    while (fgets(line, buffer_size, fp_config))
-    {
-	const char * str_config;
-	int is_same;
-	int itarget;
-
-	if (line[0] != '#')
-	    continue;
-	if ((str_config = strstr(line, "CONFIG_")) == NULL)
-	    continue;
-
-	/* Make the output file name. */
-	str_config += sizeof("CONFIG_") - 1;
-	for (itarget = 0; !isspace(str_config[itarget]); itarget++)
-	{
-	    int c = (unsigned char) str_config[itarget];
-	    if (isupper(c)) c = tolower(c);
-	    if (c == '_')   c = '/';
-	    ptarget[itarget] = c;
-	}
-	ptarget[itarget++] = '.';
-	ptarget[itarget++] = 'h';
-	ptarget[itarget++] = '\0';
-
-	/* Check for existing file. */
-	is_same = 0;
-	if ((fp_target = fopen(ptarget, "r")) != NULL)
-	{
-	    fgets(old_line, buffer_size, fp_target);
-	    if (fclose(fp_target) != 0)
-		ERROR_EXIT(ptarget);
-	    if (!strcmp(line, old_line))
-		is_same = 1;
-	}
-
-	if (!is_same)
-	{
-	    /* Auto-create directories. */
-	    int islash;
-	    for (islash = 0; islash < itarget; islash++)
-	    {
-		if (ptarget[islash] == '/')
-		{
-		    ptarget[islash] = '\0';
-		    if (stat(ptarget, &stat_buf) != 0
-		    &&  mkdir(ptarget, 0755)     != 0)
-			ERROR_EXIT( ptarget );
-		    ptarget[islash] = '/';
-		}
-	    }
-
-	    /* Write the file. */
-	    if ((fp_target = fopen(ptarget, "w" )) == NULL)
-		ERROR_EXIT(ptarget);
-	    fputs(line, fp_target);
-	    if (ferror(fp_target) || fclose(fp_target) != 0)
-		ERROR_EXIT(ptarget);
-	}
-
-	/* Update target list */
-	ptarget += itarget;
-	*(ptarget-1) = '\n';
-    }
-
-    /*
-     * Close autoconfig file.
-     * Terminate the target list.
-     */
-    if (fclose(fp_config) != 0)
-	ERROR_EXIT(str_file_autoconf);
-    *ptarget = '\0';
-
-    /*
-     * Fix up existing files which have no new value.
-     * This is Case 4 and Case 5.
-     *
-     * I re-read the tree and filter it against list_target.
-     * This is crude.  But it avoids data copies.  Also, list_target
-     * is compact and contiguous, so it easily fits into cache.
-     *
-     * Notice that list_target contains strings separated by \n,
-     * with a \n before the first string and after the last.
-     * fgets gives the incoming names a terminating \n.
-     * So by having an initial \n, strstr will find exact matches.
-     */
-
-    fp_find = popen("find * -type f -name \"*.h\" -print", "r");
-    if (fp_find == 0)
-	ERROR_EXIT( "find" );
-
-    line[0] = '\n';
-    while (fgets(line+1, buffer_size, fp_find))
-    {
-	if (strstr(list_target, line) == NULL)
-	{
-	    /*
-	     * This is an old file with no CONFIG_* flag in autoconf.h.
-	     */
-
-	    /* First strip the \n. */
-	    line[strlen(line)-1] = '\0';
-
-	    /* Grab size. */
-	    if (stat(line+1, &stat_buf) != 0)
-		ERROR_EXIT(line);
-
-	    /* If file is not empty, make it empty and give it a fresh date. */
-	    if (stat_buf.st_size != 0)
-	    {
-		if ((fp_target = fopen(line+1, "w")) == NULL)
-		    ERROR_EXIT(line);
-		if (fclose(fp_target) != 0)
-		    ERROR_EXIT(line);
-	    }
-	}
-    }
-
-    if (pclose(fp_find) != 0)
-	ERROR_EXIT("find");
-
-    return 0;
-}
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index ca693fcd023..e28cd0c2ca0 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -5,6 +5,7 @@
 
 #include <sys/stat.h>
 #include <ctype.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -520,6 +521,119 @@ int conf_write(const char *name)
 	return 0;
 }
 
+int conf_split_config(void)
+{
+	char *name, path[128];
+	char *s, *d, c;
+	struct symbol *sym;
+	struct stat sb;
+	int res, i, fd;
+
+	name = getenv("KCONFIG_AUTOCONFIG");
+	if (!name)
+		name = "include/config/auto.conf";
+	conf_read_simple(name, S_DEF_AUTO);
+
+	if (chdir("include/config"))
+		return 1;
+
+	res = 0;
+	for_all_symbols(i, sym) {
+		sym_calc_value(sym);
+		if ((sym->flags & SYMBOL_AUTO) || !sym->name)
+			continue;
+		if (sym->flags & SYMBOL_WRITE) {
+			if (sym->flags & SYMBOL_DEF_AUTO) {
+				/*
+				 * symbol has old and new value,
+				 * so compare them...
+				 */
+				switch (sym->type) {
+				case S_BOOLEAN:
+				case S_TRISTATE:
+					if (sym_get_tristate_value(sym) ==
+					    sym->def[S_DEF_AUTO].tri)
+						continue;
+					break;
+				case S_STRING:
+				case S_HEX:
+				case S_INT:
+					if (!strcmp(sym_get_string_value(sym),
+						    sym->def[S_DEF_AUTO].val))
+						continue;
+					break;
+				default:
+					break;
+				}
+			} else {
+				/*
+				 * If there is no old value, only 'no' (unset)
+				 * is allowed as new value.
+				 */
+				switch (sym->type) {
+				case S_BOOLEAN:
+				case S_TRISTATE:
+					if (sym_get_tristate_value(sym) == no)
+						continue;
+					break;
+				default:
+					break;
+				}
+			}
+		} else if (!(sym->flags & SYMBOL_DEF_AUTO))
+			/* There is neither an old nor a new value. */
+			continue;
+		/* else
+		 *	There is an old value, but no new value ('no' (unset)
+		 *	isn't saved in auto.conf, so the old value is always
+		 *	different from 'no').
+		 */
+
+		/* Replace all '_' and append ".h" */
+		s = sym->name;
+		d = path;
+		while ((c = *s++)) {
+			c = tolower(c);
+			*d++ = (c == '_') ? '/' : c;
+		}
+		strcpy(d, ".h");
+
+		/* Assume directory path already exists. */
+		fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		if (fd == -1) {
+			if (errno != ENOENT) {
+				res = 1;
+				break;
+			}
+			/*
+			 * Create directory components,
+			 * unless they exist already.
+			 */
+			d = path;
+			while ((d = strchr(d, '/'))) {
+				*d = 0;
+				if (stat(path, &sb) && mkdir(path, 0755)) {
+					res = 1;
+					goto out;
+				}
+				*d++ = '/';
+			}
+			/* Try it again. */
+			fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+			if (fd == -1) {
+				res = 1;
+				break;
+			}
+		}
+		close(fd);
+	}
+out:
+	if (chdir("../.."))
+		return 1;
+
+	return res;
+}
+
 int conf_write_autoconf(void)
 {
 	struct symbol *sym;
@@ -529,8 +643,13 @@ int conf_write_autoconf(void)
 	time_t now;
 	int i, l;
 
+	sym_clear_all_valid();
+
 	file_write_dep("include/config/auto.conf.cmd");
 
+	if (conf_split_config())
+		return 1;
+
 	out = fopen(".tmpconfig", "w");
 	if (!out)
 		return 1;
@@ -558,8 +677,6 @@ int conf_write_autoconf(void)
 		       "#define AUTOCONF_INCLUDED\n",
 		       sym_get_string_value(sym), ctime(&now));
 
-	sym_clear_all_valid();
-
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
 		if (!(sym->flags & SYMBOL_WRITE) || !sym->name)
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
index 998cf4f656b..ffd42c7007e 100644
--- a/scripts/kconfig/expr.h
+++ b/scripts/kconfig/expr.h
@@ -65,6 +65,7 @@ enum symbol_type {
 
 enum {
 	S_DEF_USER,		/* main user value */
+	S_DEF_AUTO,
 };
 
 struct symbol {
@@ -97,7 +98,7 @@ struct symbol {
 #define SYMBOL_WARNED		0x8000
 #define SYMBOL_DEF		0x10000
 #define SYMBOL_DEF_USER		0x10000
-#define SYMBOL_DEF2		0x20000
+#define SYMBOL_DEF_AUTO		0x20000
 #define SYMBOL_DEF3		0x40000
 #define SYMBOL_DEF4		0x80000