summaryrefslogtreecommitdiff
path: root/scripts/bb_mkdep.c
diff options
context:
space:
mode:
author"Vladimir N. Oleynik"2005-09-12 12:33:27 +0000
committer"Vladimir N. Oleynik"2005-09-12 12:33:27 +0000
commit5e60dc4a209b053e8fe5170bd143173941c4634c (patch)
tree43f8c3bf33914c701b2224b218d2ed21078ef2ea /scripts/bb_mkdep.c
parentba50217281e9265aa5935d184f698204143e765f (diff)
downloadbusybox-5e60dc4a209b053e8fe5170bd143173941c4634c.zip
busybox-5e60dc4a209b053e8fe5170bd143173941c4634c.tar.gz
new my scripts/mm_mkdep, dependences work now
Diffstat (limited to 'scripts/bb_mkdep.c')
-rw-r--r--scripts/bb_mkdep.c855
1 files changed, 855 insertions, 0 deletions
diff --git a/scripts/bb_mkdep.c b/scripts/bb_mkdep.c
new file mode 100644
index 0000000..4083973
--- /dev/null
+++ b/scripts/bb_mkdep.c
@@ -0,0 +1,855 @@
+/*
+ * Another dependences for Makefile mashine generator
+ *
+ * Copyright (C) 2005 by Vladimir Oleynik <dzo@simtreas.ru>
+ *
+ * This programm do
+ * 1) find #define KEY VALUE or #undef KEY from include/config.h
+ * 2) save include/config/key*.h if changed after previous usage
+ * 3) recursive scan from "./" *.[ch] files, but skip scan include/config/...
+ * 4) find #include "*.h" and KEYs using, if not as #define and #undef
+ * 5) generate depend to stdout
+ * path/file.o: include/config/key*.h found_include_*.h
+ * path/inc.h: include/config/key*.h found_included_include_*.h
+ * This programm do not generate dependences for #include <...>
+ *
+ * Options:
+ * -I local_include_path (include`s paths, default: LOCAL_INCLUDE_PATH)
+ * -d (don`t generate depend)
+ * -w (show warning if include files not found)
+ * -k include/config (default: INCLUDE_CONFIG_PATH)
+ * -c include/config.h (configs, default: INCLUDE_CONFIG_KEYS_PATH)
+*/
+
+#define LOCAL_INCLUDE_PATH "include"
+#define INCLUDE_CONFIG_PATH LOCAL_INCLUDE_PATH"/config"
+#define INCLUDE_CONFIG_KEYS_PATH LOCAL_INCLUDE_PATH"/config.h"
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <getopt.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+typedef struct BB_KEYS {
+ char *keyname;
+ const char *value;
+ char *stored_path;
+ int checked;
+ struct BB_KEYS *next;
+} bb_key_t;
+
+
+/* partial and simplify libbb routine */
+
+void bb_error_d(const char *s, ...) __attribute__ ((noreturn, format (printf, 1, 2)));
+char * bb_asprint(const char *format, ...) __attribute__ ((format (printf, 1, 2)));
+
+/* stolen from libbb as is */
+typedef struct llist_s {
+ char *data;
+ struct llist_s *link;
+} llist_t;
+llist_t *llist_add_to(llist_t *old_head, char *new_item);
+void *xrealloc(void *p, size_t size);
+void *xmalloc(size_t size);
+char *bb_xstrdup(const char *s);
+char *bb_simplify_path(const char *path);
+
+/* for lexical analyzier */
+static bb_key_t *key_top;
+
+static void parse_inc(const char *include, const char *fname);
+static void parse_conf_opt(char *opt, const char *val, size_t rsz);
+
+#define CHECK_ONLY 0
+#define MAKE_NEW 1
+static bb_key_t *find_already(bb_key_t *k, const char *nk, int flg_save_new);
+
+#define yy_error_d(s) bb_error_d("%s:%d hmm, %s", fname, line, s)
+
+/* state */
+#define S 0 /* start state */
+#define STR '"' /* string */
+#define CHR '\'' /* char */
+#define REM '*' /* block comment */
+#define POUND '#' /* # */
+#define I 'i' /* #include preprocessor`s directive */
+#define D 'd' /* #define preprocessor`s directive */
+#define U 'u' /* #undef preprocessor`s directive */
+#define LI 'I' /* #include "... */
+#define DK 'K' /* #define KEY... (config mode) */
+#define DV 'V' /* #define KEY "... or #define KEY '... */
+#define NLC 'n' /* \+\n */
+#define ANY '?' /* skip unparsed . */
+
+/* [A-Z_a-z] */
+#define ID(c) ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
+/* [A-Z_a-z0-9] */
+#define ISALNUM(c) (ID(c) || (c >= '0' && c <= '9'))
+
+#define getc1() do { c = (optr >= oend) ? EOF : *optr++; } while(0)
+#define ungetc1() optr--
+
+#define put_id(c) do { if(id_len == mema_id) \
+ id = xrealloc(id, mema_id += 16); \
+ id[id_len++] = c; } while(0)
+
+/* stupid C lexical analizator */
+static void c_lex(const char *fname, int flg_config_include)
+{
+ int c = EOF; /* stupid initialize */
+ int prev_state = EOF;
+ int called;
+ int state;
+ int line;
+ static size_t mema_id;
+ char *id = xmalloc(mema_id=128); /* fist allocate */
+ size_t id_len = 0; /* stupid initialize */
+ char *val = NULL;
+ unsigned char *optr, *oend;
+ unsigned char *start = NULL; /* stupid initialize */
+
+ int fd;
+ char *map;
+ int mapsize;
+ {
+ /* stolen from mkdep by Linus Torvalds */
+ int pagesizem1 = getpagesize() - 1;
+ struct stat st;
+
+ fd = open(fname, O_RDONLY);
+ if(fd < 0) {
+ perror(fname);
+ return;
+ }
+ fstat(fd, &st);
+ if (st.st_size == 0)
+ bb_error_d("%s is empty", fname);
+ mapsize = st.st_size;
+ mapsize = (mapsize+pagesizem1) & ~pagesizem1;
+ map = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
+ if ((long) map == -1)
+ bb_error_d("%s: mmap: %m", fname);
+
+ /* hereinafter is my */
+ optr = (unsigned char *)map;
+ oend = optr + st.st_size;
+ }
+
+ line = 1;
+ called = state = S;
+
+ for(;;) {
+ if(state == LI || state == DV) {
+ /* store "include.h" or config mode #define KEY "|'..."|' */
+ put_id(0);
+ if(state == LI) {
+ parse_inc(id, fname);
+ } else {
+ /*
+ if(val[0] == '\0')
+ yy_error_d("expected value");
+ */
+ parse_conf_opt(id, val, (optr - start));
+ }
+ state = S;
+ }
+ if(prev_state != state) {
+ prev_state = state;
+ getc1();
+ }
+
+ /* [ \t]+ eat first space */
+ while(c == ' ' || c == '\t')
+ getc1();
+
+ if(c == '\\') {
+ getc1();
+ if(c == '\n') {
+ /* \\\n eat continued */
+ line++;
+ prev_state = NLC;
+ continue;
+ }
+ ungetc1();
+ c = '\\';
+ }
+
+ if(state == S) {
+ while(c <= ' ' && c != EOF) {
+ /* <S>[\000- ]+ */
+ if(c == '\n')
+ line++;
+ getc1();
+ }
+ if(c == EOF) {
+ /* <S><<EOF>> */
+ munmap(map, mapsize);
+ close(fd);
+ return;
+ }
+ if(c == '/') {
+ /* <S>/ */
+ getc1();
+ if(c == '/') {
+ /* <S>"//"[^\n]* */
+ do getc1(); while(c != '\n' && c != EOF);
+ } else if(c == '*') {
+ /* <S>[/][*] */
+ called = S;
+ state = REM;
+ }
+ /* eat <S>/ */
+ } else if(c == '#') {
+ /* <S>\"|\'|# */
+ start = optr - 1;
+ state = c;
+ } else if(c == STR || c == CHR) {
+ /* <S>\"|\'|# */
+ val = NULL;
+ called = S;
+ state = c;
+ } else if(ISALNUM(c)) {
+ /* <S>[A-Z_a-z0-9] */
+ id_len = 0;
+ do {
+ /* <S>[A-Z_a-z0-9]+ */
+ put_id(c);
+ getc1();
+ } while(ISALNUM(c));
+ put_id(0);
+ find_already(key_top, id, CHECK_ONLY);
+ } else {
+ /* <S>. */
+ prev_state = ANY;
+ }
+ continue;
+ }
+ if(state == REM) {
+ for(;;) {
+ /* <REM>[^*]+ */
+ while(c != '*') {
+ if(c == '\n') {
+ /* <REM>\n */
+ if(called != S)
+ yy_error_d("unexpected newline");
+ line++;
+ } else if(c == EOF)
+ yy_error_d("unexpected EOF");
+ getc1();
+ }
+ /* <REM>[*] */
+ getc1();
+ if(c == '/') {
+ /* <REM>[*][/] */
+ state = called;
+ break;
+ }
+ }
+ continue;
+ }
+ if(state == STR || state == CHR) {
+ for(;;) {
+ /* <STR,CHR>\n|<<EOF>> */
+ if(c == '\n' || c == EOF)
+ yy_error_d("unterminating");
+ if(c == '\\') {
+ /* <STR,CHR>\\ */
+ getc1();
+ if(c != '\\' && c != '\n' && c != state) {
+ /* another usage \ in str or char */
+ if(c == EOF)
+ yy_error_d("unexpected EOF");
+ if(val)
+ put_id(c);
+ continue;
+ }
+ /* <STR,CHR>\\[\\\n] or <STR>\\\" or <CHR>\\\' */
+ /* eat 2 char */
+ if(c == '\n')
+ line++;
+ else if(val)
+ put_id(c);
+ } else if(c == state) {
+ /* <STR>\" or <CHR>\' */
+ if(called == DV)
+ put_id(c);
+ state = called;
+ break;
+ } else if(val)
+ put_id(c);
+ /* <STR,CHR>. */
+ getc1();
+ }
+ continue;
+ }
+
+ /* begin preprocessor states */
+ if(c == EOF)
+ yy_error_d("unexpected EOF");
+ if(c == '/') {
+ /* <#.*>/ */
+ getc1();
+ if(c == '/')
+ yy_error_d("detect // in preprocessor line");
+ if(c == '*') {
+ /* <#.*>[/][*] */
+ called = state;
+ state = REM;
+ continue;
+ }
+ /* hmm, #.*[/] */
+ yy_error_d("strange preprocessor line");
+ }
+ if(state == '#') {
+ static const char * const preproc[] = {
+ "define", "undef", "include", ""
+ };
+ const char * const *str_type;
+
+ id_len = 0;
+ while(ISALNUM(c)) {
+ put_id(c);
+ getc1();
+ }
+ put_id(0);
+ for(str_type = preproc; (state = **str_type); str_type++) {
+ if(*id == state && strcmp(id, *str_type) == 0)
+ break;
+ }
+ /* to S if another #directive */
+ ungetc1();
+ id_len = 0; /* common for save */
+ continue;
+ }
+ if(state == I) {
+ if(c == STR) {
+ /* <I>\" */
+ val = id;
+ state = STR;
+ called = LI;
+ continue;
+ }
+ /* another (may be wrong) #include ... */
+ ungetc1();
+ state = S;
+ continue;
+ }
+ if(state == D || state == U) {
+ while(ISALNUM(c)) {
+ if(flg_config_include) {
+ /* save KEY from #"define"|"undef" ... */
+ put_id(c);
+ }
+ getc1();
+ }
+ if(!flg_config_include) {
+ state = S;
+ } else {
+ if(!id_len)
+ yy_error_d("expected identificator");
+ put_id(0);
+ if(state == U) {
+ parse_conf_opt(id, NULL, (optr - start));
+ state = S;
+ } else {
+ /* D -> DK */
+ state = DK;
+ }
+ }
+ ungetc1();
+ continue;
+ }
+ if(state == DK) {
+ /* #define (config mode) */
+ val = id + id_len;
+ if(c == STR || c == CHR) {
+ /* define KEY "... or define KEY '... */
+ put_id(c);
+ called = DV;
+ state = c;
+ continue;
+ }
+ while(ISALNUM(c)) {
+ put_id(c);
+ getc1();
+ }
+ ungetc1();
+ state = DV;
+ continue;
+ }
+ }
+}
+
+
+static void show_usage(void) __attribute__ ((noreturn));
+static void show_usage(void)
+{
+ bb_error_d("Usage: [-I local_include_path] [-dw] "
+ "[-k path_for_store_keys] [-s skip_file]");
+}
+
+static const char *kp;
+static llist_t *Iop;
+static bb_key_t *Ifound;
+static int noiwarning;
+static llist_t *configs;
+
+static bb_key_t *find_already(bb_key_t *k, const char *nk, int flg_save_new)
+{
+ bb_key_t *cur;
+
+ for(cur = k; cur; cur = cur->next) {
+ if(strcmp(cur->keyname, nk) == 0) {
+ cur->checked = 1;
+ return NULL;
+ }
+ }
+ if(flg_save_new == CHECK_ONLY)
+ return NULL;
+ cur = xmalloc(sizeof(bb_key_t));
+ cur->keyname = bb_xstrdup(nk);
+ cur->checked = 1;
+ cur->next = k;
+ return cur;
+}
+
+static int store_include_fullpath(char *p_i, bb_key_t *li)
+{
+ struct stat st;
+ int ok = 0;
+
+ if(stat(p_i, &st) == 0) {
+ li->stored_path = bb_simplify_path(p_i);
+ ok = 1;
+ }
+ free(p_i);
+ return ok;
+}
+
+static void parse_inc(const char *include, const char *fname)
+{
+ bb_key_t *li;
+ char *p_i;
+ llist_t *lo;
+
+ if((li = find_already(Ifound, include, MAKE_NEW)) == NULL)
+ return;
+ Ifound = li;
+ if(include[0] != '/') {
+ /* relative */
+ int w;
+ const char *p;
+
+ p_i = strrchr(fname, '/');
+ if(p_i == NULL) {
+ p = ".";
+ w = 1;
+ } else {
+ w = (p_i-fname);
+ p = fname;
+ }
+ p_i = bb_asprint("%.*s/%s", w, p, include);
+ if(store_include_fullpath(p_i, li))
+ return;
+ }
+ for(lo = Iop; lo; lo = lo->link) {
+ p_i = bb_asprint("%s/%s", lo->data, include);
+ if(store_include_fullpath(p_i, li))
+ return;
+ }
+ li->stored_path = NULL;
+ if(noiwarning)
+ fprintf(stderr, "%s: Warning: #include \"%s\" not found in specified paths\n", fname, include);
+}
+
+static void parse_conf_opt(char *opt, const char *val, size_t recordsz)
+{
+ bb_key_t *cur = find_already(key_top, opt, MAKE_NEW);
+
+ if(cur != NULL) {
+ /* new key, check old key if present after previous usage */
+ char *s, *p;
+ struct stat st;
+ int fd;
+ int cmp_ok = 0;
+ static char *record_buf;
+ static char *r_cmp;
+ static size_t r_sz;
+
+ recordsz += 2; /* \n\0 */
+ if(recordsz > r_sz) {
+ record_buf = xrealloc(record_buf, r_sz=recordsz);
+ r_cmp = xrealloc(r_cmp, recordsz);
+ }
+ s = record_buf;
+ if(val)
+ sprintf(s, "#define %s%s%s\n", opt, (*val ? " " : ""), val);
+ else
+ sprintf(s, "#undef %s\n", opt);
+ /* may be short count " " */
+ recordsz = strlen(s);
+ /* key converting [A-Z] -> [a-z] */
+ for(p = opt; *p; p++) {
+ if(*p >= 'A' && *p <= 'Z')
+ *p = *p - 'A' + 'a';
+ if(*p == '_')
+ *p = '/';
+ }
+ p = bb_asprint("%s/%s.h", kp, opt);
+ cur->stored_path = opt = p;
+ while(*++p) {
+ /* Auto-create directories. */
+ if (*p == '/') {
+ *p = '\0';
+ if (stat(opt, &st) != 0 && mkdir(opt, 0755) != 0)
+ bb_error_d("mkdir(%s): %m", opt);
+ *p = '/';
+ }
+ }
+ if(stat(opt, &st) == 0) {
+ /* found */
+ if(st.st_size == recordsz) {
+ fd = open(opt, O_RDONLY);
+ if(fd < 0 || read(fd, r_cmp, recordsz) != recordsz)
+ bb_error_d("%s: %m", opt);
+ close(fd);
+ cmp_ok = memcmp(s, r_cmp, recordsz) == 0;
+ }
+ }
+ if(!cmp_ok) {
+ fd = open(opt, O_WRONLY|O_CREAT|O_TRUNC, 0644);
+ if(fd < 0 || write(fd, s, recordsz) != recordsz)
+ bb_error_d("%s: %m", opt);
+ close(fd);
+ }
+ /* store only */
+ cur->checked = 0;
+ if(val) {
+ if(*val == '\0') {
+ cur->value = "";
+ } else {
+ cur->value = bb_xstrdup(val);
+ }
+ } else {
+ cur->value = NULL;
+ }
+ key_top = cur;
+ } else {
+ /* present already */
+ for(cur = key_top; cur; cur = cur->next) {
+ if(strcmp(cur->keyname, opt) == 0) {
+ cur->checked = 0;
+ if(cur->value == NULL && val == NULL)
+ return;
+ if((cur->value == NULL && val != NULL) ||
+ (cur->value != NULL && val == NULL) ||
+ strcmp(cur->value, val))
+ fprintf(stderr, "Warning: redefined %s\n", opt);
+ return;
+ }
+ }
+ }
+}
+
+static int show_dep(int first, bb_key_t *k, const char *a)
+{
+ bb_key_t *cur;
+
+ for(cur = k; cur; cur = cur->next) {
+ if(cur->checked && cur->stored_path) {
+ if(first) {
+ const char *ext;
+
+ if(*a == '.' && a[1] == '/')
+ a += 2;
+ ext = strrchr(a, '.');
+ if(ext && ext[1] == 'c' && ext[2] == '\0') {
+ /* *.c -> *.o */
+ printf("\n%.*s.o:", (ext - a), a);
+ } else {
+ printf("\n%s:", a);
+ }
+ first = 0;
+ } else {
+ printf(" \\\n ");
+ }
+ printf(" %s", cur->stored_path);
+ }
+ cur->checked = 0;
+ }
+ return first;
+}
+
+static llist_t *files;
+
+static llist_t *filter_chd(const char *fe, const char *p, llist_t *pdirs)
+{
+ const char *e;
+ struct stat st;
+ char *fp;
+ char *afp;
+ llist_t *cfl;
+
+ if (*fe == '.')
+ return NULL;
+ fp = bb_asprint("%s/%s", p, fe);
+ if(stat(fp, &st)) {
+ fprintf(stderr, "Warning: stat(%s): %m", fp);
+ free(fp);
+ return NULL;
+ }
+ afp = bb_simplify_path(fp);
+ if(S_ISDIR(st.st_mode)) {
+ if(strcmp(kp, afp) == 0) {
+ /* is autogenerated to kp/key* by previous usage */
+ free(afp);
+ free(fp);
+ /* drop scan kp/ directory */
+ return NULL;
+ }
+ free(afp);
+ return llist_add_to(pdirs, fp);
+ }
+ if(!S_ISREG(st.st_mode)) {
+ /* hmm, is device! */
+ free(afp);
+ free(fp);
+ return NULL;
+ }
+ e = strrchr(fe, '.');
+ if(e == NULL || !((e[1]=='c' || e[1]=='h') && e[2]=='\0')) {
+ /* direntry is not directory or *.[ch] */
+ free(afp);
+ free(fp);
+ return NULL;
+ }
+ for(cfl = configs; cfl; cfl = cfl->link) {
+ if(cfl->data && strcmp(cfl->data, afp) == 0) {
+ /* parse configs.h */
+ free(afp);
+ c_lex(fp, 1);
+ free(fp);
+ free(cfl->data);
+ cfl->data = NULL;
+ return NULL;
+ }
+ }
+ free(fp);
+ /* direntry is *.[ch] regular file */
+ files = llist_add_to(files, afp);
+ return NULL;
+}
+
+static void scan_dir_find_ch_files(char *p)
+{
+ llist_t *dirs;
+ llist_t *d_add;
+ llist_t *d;
+ struct dirent *de;
+ DIR *dir;
+
+ dirs = llist_add_to(NULL, p);
+ /* emulate recursive */
+ while(dirs) {
+ d_add = NULL;
+ while(dirs) {
+ dir = opendir(dirs->data);
+ if (dir == NULL)
+ fprintf(stderr, "Warning: opendir(%s): %m", dirs->data);
+ while ((de = readdir(dir)) != NULL) {
+ d = filter_chd(de->d_name, dirs->data, d_add);
+ if(d)
+ d_add = d;
+ }
+ closedir(dir);
+ if(dirs->data != p)
+ free(dirs->data);
+ d = dirs;
+ dirs = dirs->link;
+ free(d);
+ }
+ dirs = d_add;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int generate_dep = 1;
+ char *s;
+ int i;
+ llist_t *fl;
+
+ while ((i = getopt(argc, argv, "I:c:dk:w")) > 0) {
+ switch(i) {
+ case 'I':
+ Iop = llist_add_to(Iop, optarg);
+ break;
+ case 'c':
+ s = bb_simplify_path(optarg);
+ configs = llist_add_to(configs, s);
+ break;
+ case 'd':
+ generate_dep = 0;
+ break;
+ case 'k':
+ if(kp)
+ bb_error_d("Hmm, why multiple -k?");
+ kp = bb_simplify_path(optarg);
+ break;
+ case 'w':
+ noiwarning = 1;
+ break;
+ default:
+ show_usage();
+ }
+ }
+ if(argc > optind)
+ show_usage();
+
+ /* defaults */
+ if(kp == NULL)
+ kp = bb_simplify_path(INCLUDE_CONFIG_PATH);
+ if(Iop == NULL)
+ Iop = llist_add_to(Iop, LOCAL_INCLUDE_PATH);
+ if(configs == NULL) {
+ s = bb_simplify_path(INCLUDE_CONFIG_KEYS_PATH);
+ configs = llist_add_to(configs, s);
+ }
+ scan_dir_find_ch_files(".");
+
+ for(fl = files; fl; fl = fl->link) {
+ c_lex(fl->data, 0);
+ if(generate_dep) {
+ i = show_dep(1, Ifound, fl->data);
+ i = show_dep(i, key_top, fl->data);
+ if(i == 0)
+ putchar('\n');
+ }
+ }
+ return 0;
+}
+
+void bb_error_d(const char *s, ...)
+{
+ va_list p;
+
+ va_start(p, s);
+ vfprintf(stderr, s, p);
+ va_end(p);
+ putc('\n', stderr);
+ exit(1);
+}
+
+
+void *xmalloc(size_t size)
+{
+ void *p = malloc(size);
+
+ if(p == NULL)
+ bb_error_d("memory exhausted");
+ return p;
+}
+
+void *xrealloc(void *p, size_t size) {
+ p = realloc(p, size);
+ if(p == NULL)
+ bb_error_d("memory exhausted");
+ return p;
+}
+
+char *bb_asprint(const char *format, ...)
+{
+ va_list p;
+ int r;
+ char *out;
+
+ va_start(p, format);
+ r = vasprintf(&out, format, p);
+ va_end(p);
+
+ if (r < 0)
+ bb_error_d("bb_asprint: %m");
+ return out;
+}
+
+llist_t *llist_add_to(llist_t *old_head, char *new_item)
+{
+ llist_t *new_head;
+
+ new_head = xmalloc(sizeof(llist_t));
+ new_head->data = new_item;
+ new_head->link = old_head;
+
+ return(new_head);
+}
+
+char *bb_xstrdup(const char *s)
+{
+ char *r = strdup(s);
+ if(r == NULL)
+ bb_error_d("memory exhausted");
+ return r;
+}
+
+char *bb_simplify_path(const char *path)
+{
+ char *s, *start, *p;
+
+ if (path[0] == '/')
+ start = bb_xstrdup(path);
+ else {
+ static char *pwd;
+
+ if(pwd == NULL) {
+ /* is not libbb, but this program have not chdir() */
+ unsigned path_max = 512;
+ char *cwd = xmalloc (path_max);
+#define PATH_INCR 32
+ while (getcwd (cwd, path_max) == NULL) {
+ if(errno != ERANGE)
+ bb_error_d("getcwd: %m");
+ path_max += PATH_INCR;
+ cwd = xrealloc (cwd, path_max);
+ }
+ pwd = cwd;
+ }
+ start = bb_asprint("%s/%s", pwd, path);
+ }
+ p = s = start;
+
+ do {
+ if (*p == '/') {
+ if (*s == '/') { /* skip duplicate (or initial) slash */
+ continue;
+ } else if (*s == '.') {
+ if (s[1] == '/' || s[1] == 0) { /* remove extra '.' */
+ continue;
+ } else if ((s[1] == '.') && (s[2] == '/' || s[2] == 0)) {
+ ++s;
+ if (p > start) {
+ while (*--p != '/'); /* omit previous dir */
+ }
+ continue;
+ }
+ }
+ }
+ *++p = *s;
+ } while (*++s);
+
+ if ((p == start) || (*p != '/')) { /* not a trailing slash */
+ ++p; /* so keep last character */
+ }
+ *p = 0;
+
+ return start;
+}