nuttx/libs/libc: add regex implementation

add regex implementation for libc, the implementation are ported from
musl project

Signed-off-by: guoshichao <guoshichao@xiaomi.com>

include/regex.h

@@ -0,0 +1,104 @@
+/****************************************************************************
+ * include/regex.h
+ *
+ * regex.h - TRE POSIX compatible regex compilation functions.
+ *
+ *  Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+ *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+ *  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef _INCLUDE_REGEX_H
+#define _INCLUDE_REGEX_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <sys/types.h>
+
+#define regoff_t  int
+
+typedef struct re_pattern_buffer
+{
+  size_t re_nsub;
+  void *__opaque;
+  void *__padding[4];
+  size_t __nsub2;
+  char __padding2;
+} regex_t;
+
+typedef struct
+{
+  regoff_t rm_so;
+  regoff_t rm_eo;
+} regmatch_t;
+
+#define RE_DUP_MAX      255
+
+#define REG_EXTENDED    1
+#define REG_ICASE       2
+#define REG_NEWLINE     4
+#define REG_NOSUB       8
+
+#define REG_NOTBOL      1
+#define REG_NOTEOL      2
+
+#define REG_OK          0
+#define REG_NOMATCH     1
+#define REG_BADPAT      2
+#define REG_ECOLLATE    3
+#define REG_ECTYPE      4
+#define REG_EESCAPE     5
+#define REG_ESUBREG     6
+#define REG_EBRACK      7
+#define REG_EPAREN      8
+#define REG_EBRACE      9
+#define REG_BADBR       10
+#define REG_ERANGE      11
+#define REG_ESPACE      12
+#define REG_BADRPT      13
+
+#define REG_ENOSYS      -1
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+int regcomp(regex_t *__restrict, const char *__restrict, int);
+
+int regexec(const regex_t * __restrict, const char *__restrict, size_t,
+            regmatch_t *__restrict, int);
+void regfree(regex_t *);
+
+size_t regerror(int, const regex_t *__restrict, char *__restrict, size_t);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _INCLUDE_REGEX_H */

libs/libc/Kconfig

@@ -29,3 +29,4 @@ source "libs/libc/userfs/Kconfig"
 source "libs/libc/builtin/Kconfig"
 source "libs/libc/symtab/Kconfig"
 source "libs/libc/stream/Kconfig"
+source "libs/libc/regex/Kconfig"

libs/libc/Makefile

@@ -45,6 +45,7 @@ include obstack/Make.defs
 include pthread/Make.defs
 include pwd/Make.defs
 include queue/Make.defs
+include regex/Make.defs
 include sched/Make.defs
 include semaphore/Make.defs
 include signal/Make.defs

libs/libc/regex/Kconfig

@@ -0,0 +1,10 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config LIBC_REGEX
+	bool "Enable regex"
+	default n
+	---help---
+		provide the regex related func, include regcomp, regexec.

libs/libc/regex/Make.defs

@@ -0,0 +1,30 @@
+############################################################################
+# libs/libc/regex/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+ifeq ($(CONFIG_LIBC_REGEX),y)
+
+# Add the regex C files to the build
+CSRCS += regcomp.c regexec.c regerror.c tre-mem.c
+
+# Add the regex directory to the build
+DEPPATH += --dep-path regex
+VPATH += :regex
+
+endif