tools/nolibc: add getopt()

Introduce a getopt() implementation based on the one from musl.
The only deviations are adaption to the kernel coding style and nolibc
infrastructure and removal of multi-byte support.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index b5d4479abc3b727b6260b9c6ecd34d2b25906c2b..e05862cd08051685112f067d6eb45716613dd43c 100644 (file)
--- a/tools/include/nolibc/Makefile
+++ b/tools/include/nolibc/Makefile
@@ -33,6 +33,7 @@ all_files := \
                elf.h \
                errno.h \
                fcntl.h \
+               getopt.h \
                limits.h \
                nolibc.h \
                signal.h \

diff --git a/tools/include/nolibc/getopt.h b/tools/include/nolibc/getopt.h
new file mode 100644 (file)
index 0000000..5fd06c9
--- /dev/null
+++ b/tools/include/nolibc/getopt.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * getopt function definitions for NOLIBC, adapted from musl libc
+ * Copyright (C) 2005-2020 Rich Felker, et al.
+ * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
+ */
+
+#ifndef _NOLIBC_GETOPT_H
+#define _NOLIBC_GETOPT_H
+
+struct FILE;
+static struct FILE *const stderr;
+static int fprintf(struct FILE *stream, const char *fmt, ...);
+
+__attribute__((weak,unused,section(".data.nolibc_getopt")))
+char *optarg;
+
+__attribute__((weak,unused,section(".data.nolibc_getopt")))
+int optind = 1, opterr = 1, optopt;
+
+static __attribute__((unused))
+int getopt(int argc, char * const argv[], const char *optstring)
+{
+       static int __optpos;
+       int i;
+       char c, d;
+       char *optchar;
+
+       if (!optind) {
+               __optpos = 0;
+               optind = 1;
+       }
+
+       if (optind >= argc || !argv[optind])
+               return -1;
+
+       if (argv[optind][0] != '-') {
+               if (optstring[0] == '-') {
+                       optarg = argv[optind++];
+                       return 1;
+               }
+               return -1;
+       }
+
+       if (!argv[optind][1])
+               return -1;
+
+       if (argv[optind][1] == '-' && !argv[optind][2])
+               return optind++, -1;
+
+       if (!__optpos)
+               __optpos++;
+       c = argv[optind][__optpos];
+       optchar = argv[optind] + __optpos;
+       __optpos++;
+
+       if (!argv[optind][__optpos]) {
+               optind++;
+               __optpos = 0;
+       }
+
+       if (optstring[0] == '-' || optstring[0] == '+')
+               optstring++;
+
+       i = 0;
+       d = 0;
+       do {
+               d = optstring[i++];
+       } while (d && d != c);
+
+       if (d != c || c == ':') {
+               optopt = c;
+               if (optstring[0] != ':' && opterr)
+                       fprintf(stderr, "%s: unrecognized option: %c\n", argv[0], *optchar);
+               return '?';
+       }
+       if (optstring[i] == ':') {
+               optarg = 0;
+               if (optstring[i + 1] != ':' || __optpos) {
+                       optarg = argv[optind++];
+                       if (__optpos)
+                               optarg += __optpos;
+                       __optpos = 0;
+               }
+               if (optind > argc) {
+                       optopt = c;
+                       if (optstring[0] == ':')
+                               return ':';
+                       if (opterr)
+                               fprintf(stderr, "%s: option requires argument: %c\n",
+                                       argv[0], *optchar);
+                       return '?';
+               }
+       }
+       return c;
+}
+
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
+#endif /* _NOLIBC_GETOPT_H */

diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index e8843880e4dfca54dcd3f2aec33dab83cb25c17c..d1b949e094eeb7cc0fe875deeafa4c972ecf35b2 100644 (file)
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -113,6 +113,7 @@
 #include "stackprotector.h"
 #include "dirent.h"
 #include "fcntl.h"
+#include "getopt.h"
 
 /* Used by programs to avoid std includes */
 #define NOLIBC