13 files changed, 572 insertions, 36 deletions

diff --git a/auto/help b/auto/help
index f5f10010..31c68567 100644
--- a/auto/help
+++ b/auto/help
@@ -35,6 +35,8 @@ cat << END
 
   --no-ipv6            disable IPv6 support
   --no-unix-sockets    disable Unix domain sockets support
+  --no-regex           disable regular expression support
+  --no-pcre2           force using PCRE library
 
   --openssl            enable OpenSSL library usage
 
diff --git a/auto/options b/auto/options
index d315b227..b6007bc2 100644
--- a/auto/options
+++ b/auto/options
@@ -16,8 +16,11 @@ NXT_DEBUG=NO
 NXT_INET6=YES
 NXT_UNIX_DOMAIN=YES
 
-NXT_REGEX=NO
-NXT_PCRE=NO
+NXT_PCRE_CFLAGS=
+NXT_PCRE_LIB=
+
+NXT_REGEX=YES
+NXT_TRY_PCRE2=YES
 
 NXT_TLS=NO
 NXT_OPENSSL=NO
@@ -73,7 +76,8 @@ do
         --no-ipv6)                       NXT_INET6=NO                        ;;
         --no-unix-sockets)               NXT_UNIX_DOMAIN=NO                  ;;
 
-        --pcre)                          NXT_PCRE=YES                        ;;
+        --no-regex)                      NXT_REGEX=NO                        ;;
+        --no-pcre2)                      NXT_TRY_PCRE2=NO                    ;;
 
         --openssl)                       NXT_OPENSSL=YES                     ;;
         --gnutls)                        NXT_GNUTLS=YES                      ;;
diff --git a/auto/pcre b/auto/pcre
index e8765cef..955e4baf 100644
--- a/auto/pcre
+++ b/auto/pcre
@@ -3,15 +3,41 @@
 # Copyright (C) NGINX, Inc.
 
 
-NXT_REGEX=NO
-NXT_PCRE_CFLAGS=
-NXT_PCRE_LIB=
+nxt_found=no
+NXT_HAVE_PCRE2=NO
 
+if [ $NXT_TRY_PCRE2 = YES ]; then
+    if /bin/sh -c "(pcre2-config --version)" >> $NXT_AUTOCONF_ERR 2>&1; then
 
-if [ $NXT_PCRE = YES ]; then
+        NXT_PCRE_CFLAGS=`pcre2-config --cflags`
+        NXT_PCRE_LIB=`pcre2-config --libs8`
 
-    nxt_found=no
+        nxt_feature="PCRE2 library"
+        nxt_feature_name=NXT_HAVE_PCRE2
+        nxt_feature_run=no
+        nxt_feature_incs="-DPCRE2_CODE_UNIT_WIDTH=8 $NXT_PCRE_CFLAGS"
+        nxt_feature_libs=$NXT_PCRE_LIB
+        nxt_feature_test="#include <pcre2.h>
+
+                          int main(void) {
+                              pcre2_code  *re;
+
+                              re = pcre2_compile((PCRE2_SPTR)\"\",
+                                                 PCRE2_ZERO_TERMINATED, 0,
+                                                 NULL, NULL, NULL);
+                              return (re == NULL);
+                          }"
+
+        . auto/feature
+
+        if [ $nxt_found = yes ]; then
+            NXT_HAVE_PCRE2=YES
+            $echo " + PCRE2 version: `pcre2-config --version`"
+        fi
+    fi
+fi
 
+if [ $nxt_found = no ]; then
     if /bin/sh -c "(pcre-config --version)" >> $NXT_AUTOCONF_ERR 2>&1; then
 
         NXT_PCRE_CFLAGS=`pcre-config --cflags`
@@ -33,17 +59,19 @@ if [ $NXT_PCRE = YES ]; then
                               return 0;
                           }"
         . auto/feature
-    fi
 
-    if [ $nxt_found = no ]; then
-        $echo
-        $echo $0: error: no PCRE library found.
-        $echo
-        exit 1;
+        if [ $nxt_found = yes ]; then
+            $echo " + PCRE version: `pcre-config --version`"
+        fi
     fi
+fi
 
-    NXT_REGEX=YES
-    nxt_have=NXT_REGEX . auto/have
+if [ $nxt_found = yes ]; then
+    nxt_have=NXT_HAVE_REGEX . auto/have
 
-    $echo " + PCRE version: `pcre-config --version`"
+else
+    $echo
+    $echo $0: error: no PCRE library found.
+    $echo
+    exit 1;
 fi
diff --git a/auto/sources b/auto/sources
index e44dc4bb..01fec6c1 100644
--- a/auto/sources
+++ b/auto/sources
@@ -128,6 +128,9 @@ NXT_LIB_GNUTLS_SRCS="src/nxt_gnutls.c"
 NXT_LIB_CYASSL_SRCS="src/nxt_cyassl.c"
 NXT_LIB_POLARSSL_SRCS="src/nxt_polarssl.c"
 
+NXT_LIB_PCRE_SRCS="src/nxt_pcre.c"
+NXT_LIB_PCRE2_SRCS="src/nxt_pcre2.c"
+
 NXT_LIB_EPOLL_SRCS="src/nxt_epoll_engine.c"
 NXT_LIB_KQUEUE_SRCS="src/nxt_kqueue_engine.c"
 NXT_LIB_EVENTPORT_SRCS="src/nxt_eventport_engine.c"
@@ -211,6 +214,14 @@ if [ $NXT_POLARSSL = YES ]; then
 fi
 
 
+if [ "$NXT_REGEX" = "YES" ]; then
+    if [ "$NXT_HAVE_PCRE2" = "YES" ]; then
+        NXT_LIB_SRCS="$NXT_LIB_SRCS $NXT_LIB_PCRE2_SRCS"
+    else
+        NXT_LIB_SRCS="$NXT_LIB_SRCS $NXT_LIB_PCRE_SRCS"
+    fi
+fi
+
 if [ "$NXT_HAVE_EPOLL" = "YES" -o "$NXT_TEST_BUILD_EPOLL" = "YES" ]; then
     NXT_LIB_SRCS="$NXT_LIB_SRCS $NXT_LIB_EPOLL_SRCS"
 fi
diff --git a/configure b/configure
index c67e4728..ece4f12a 100755
--- a/configure
+++ b/configure
@@ -127,7 +127,11 @@ NXT_LIBRT=
 . auto/unix
 . auto/os/conf
 . auto/ssltls
-. auto/pcre
+
+if [ $NXT_REGEX = YES ]; then
+    . auto/pcre
+fi
+
 . auto/isolation
 . auto/capability
 
diff --git a/src/nxt_conf_validation.c b/src/nxt_conf_validation.c
index f4e7c358..acb2e3de 100644
--- a/src/nxt_conf_validation.c
+++ b/src/nxt_conf_validation.c
@@ -11,6 +11,7 @@
 #include <nxt_http.h>
 #include <nxt_sockaddr.h>
 #include <nxt_http_route_addr.h>
+#include <nxt_regex.h>
 
 
 typedef enum {
@@ -1504,8 +1505,12 @@ static nxt_int_t
 nxt_conf_vldt_match_pattern(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value)
 {
-    nxt_str_t   pattern;
-    nxt_uint_t  i, first, last;
+    nxt_str_t        pattern;
+    nxt_uint_t       i, first, last;
+#if (NXT_HAVE_REGEX)
+    nxt_regex_t      *re;
+    nxt_regex_err_t  err;
+#endif
 
     if (nxt_conf_type(value) != NXT_CONF_STRING) {
         return nxt_conf_vldt_error(vldt, "The \"match\" patterns for \"host\", "
@@ -1519,6 +1524,32 @@ nxt_conf_vldt_match_pattern(nxt_conf_validation_t *vldt,
     }
 
     first = (pattern.start[0] == '!');
+
+    if (first < pattern.length && pattern.start[first] == '~') {
+#if (NXT_HAVE_REGEX)
+        pattern.start += first + 1;
+        pattern.length -= first + 1;
+
+        re = nxt_regex_compile(vldt->pool, &pattern, &err);
+        if (nxt_slow_path(re == NULL)) {
+            if (err.offset < pattern.length) {
+                return nxt_conf_vldt_error(vldt, "Invalid regular expression: "
+                                           "%s at offset %d",
+                                           err.msg, err.offset);
+            }
+
+            return nxt_conf_vldt_error(vldt, "Invalid regular expression: %s",
+                                       err.msg);
+        }
+
+        return NXT_OK;
+#else
+        return nxt_conf_vldt_error(vldt, "Unit is built without support of "
+                                   "regular expressions: \"--no-regex\" "
+                                   "./configure option was set.");
+#endif
+    }
+
     last = pattern.length - 1;
 
     for (i = first; i < last; i++) {
diff --git a/src/nxt_http.h b/src/nxt_http.h
index 08181520..1418be95 100644
--- a/src/nxt_http.h
+++ b/src/nxt_http.h
@@ -7,6 +7,8 @@
 #ifndef _NXT_HTTP_H_INCLUDED_
 #define _NXT_HTTP_H_INCLUDED_
 
+#include <nxt_regex.h>
+
 
 typedef enum {
     NXT_HTTP_UNSET = -1,
@@ -168,6 +170,10 @@ struct nxt_http_request_s {
 
     void                            *req_rpc_data;
 
+#if (NXT_HAVE_REGEX)
+    nxt_regex_match_t               *regex_match;
+#endif
+
     nxt_http_peer_t                 *peer;
     nxt_buf_t                       *last;
 
diff --git a/src/nxt_http_route.c b/src/nxt_http_route.c
index ae91076a..9aaa708e 100644
--- a/src/nxt_http_route.c
+++ b/src/nxt_http_route.c
@@ -8,6 +8,7 @@
 #include <nxt_http.h>
 #include <nxt_sockaddr.h>
 #include <nxt_http_route_addr.h>
+#include <nxt_regex.h>
 
 
 typedef enum {
@@ -76,12 +77,20 @@ typedef struct {
 
 
 typedef struct {
+    union {
+        nxt_array_t                *pattern_slices;
+#if (NXT_HAVE_REGEX)
+        nxt_regex_t                *regex;
+#endif
+    } u;
     uint32_t                       min_length;
-    nxt_array_t                    *pattern_slices;
 
     uint8_t                        case_sensitive;  /* 1 bit */
     uint8_t                        negative;        /* 1 bit */
     uint8_t                        any;             /* 1 bit */
+#if (NXT_HAVE_REGEX)
+    uint8_t                        regex;           /* 1 bit */
+#endif
 } nxt_http_route_pattern_t;
 
 
@@ -1060,24 +1069,24 @@ nxt_http_route_pattern_create(nxt_task_t *task, nxt_mp_t *mp,
     nxt_str_t                       test, tmp;
     nxt_int_t                       ret;
     nxt_array_t                     *slices;
+#if (NXT_HAVE_REGEX)
+    nxt_regex_t                     *re;
+    nxt_regex_err_t                 err;
+#endif
     nxt_http_route_pattern_type_t   type;
-
     nxt_http_route_pattern_slice_t  *slice;
 
     type = NXT_HTTP_ROUTE_PATTERN_EXACT;
 
     nxt_conf_get_string(cv, &test);
 
-    slices = nxt_array_create(mp, 1, sizeof(nxt_http_route_pattern_slice_t));
-    if (nxt_slow_path(slices == NULL)) {
-        return NXT_ERROR;
-    }
-
-    pattern->pattern_slices = slices;
-
+    pattern->u.pattern_slices = NULL;
     pattern->negative = 0;
     pattern->any = 1;
     pattern->min_length = 0;
+#if (NXT_HAVE_REGEX)
+    pattern->regex = 0;
+#endif
 
     if (test.length != 0 && test.start[0] == '!') {
         test.start++;
@@ -1087,6 +1096,41 @@ nxt_http_route_pattern_create(nxt_task_t *task, nxt_mp_t *mp,
         pattern->any = 0;
     }
 
+    if (test.length > 0 && test.start[0] == '~') {
+#if (NXT_HAVE_REGEX)
+        test.start++;
+        test.length--;
+
+        re = nxt_regex_compile(mp, &test, &err);
+        if (nxt_slow_path(re == NULL)) {
+            if (err.offset < test.length) {
+                nxt_alert(task, "nxt_regex_compile(%V) failed: %s at offset %d",
+                          &test, err.msg, (int) err.offset);
+                return NXT_ERROR;
+            }
+
+            nxt_alert(task, "nxt_regex_compile(%V) failed %s", &test, err.msg);
+
+            return NXT_ERROR;
+        }
+
+        pattern->u.regex = re;
+        pattern->regex = 1;
+
+        return NXT_OK;
+
+#else
+        return NXT_ERROR;
+#endif
+    }
+
+    slices = nxt_array_create(mp, 1, sizeof(nxt_http_route_pattern_slice_t));
+    if (nxt_slow_path(slices == NULL)) {
+        return NXT_ERROR;
+    }
+
+    pattern->u.pattern_slices = slices;
+
     if (test.length == 0) {
         slice = nxt_array_add(slices);
         if (nxt_slow_path(slice == NULL)) {
@@ -1980,6 +2024,9 @@ nxt_http_route_header(nxt_http_request_t *r, nxt_http_route_rule_t *rule)
         }
 
         ret = nxt_http_route_test_rule(r, rule, f->value, f->value_length);
+        if (nxt_slow_path(ret == NXT_ERROR)) {
+            return NXT_ERROR;
+        }
 
         if (ret == 0) {
             return ret;
@@ -2155,7 +2202,7 @@ static nxt_int_t
 nxt_http_route_test_argument(nxt_http_request_t *r,
     nxt_http_route_rule_t *rule, nxt_array_t *array)
 {
-    nxt_bool_t             ret;
+    nxt_int_t              ret;
     nxt_http_name_value_t  *nv, *end;
 
     ret = 0;
@@ -2171,6 +2218,10 @@ nxt_http_route_test_argument(nxt_http_request_t *r,
         {
             ret = nxt_http_route_test_rule(r, rule, nv->value,
                                            nv->value_length);
+            if (nxt_slow_path(ret == NXT_ERROR)) {
+                return NXT_ERROR;
+            }
+
             if (ret == 0) {
                 break;
             }
@@ -2189,7 +2240,7 @@ nxt_http_route_scheme(nxt_http_request_t *r, nxt_http_route_rule_t *rule)
     nxt_bool_t                      tls, https;
     nxt_http_route_pattern_slice_t  *pattern_slice;
 
-    pattern_slice = rule->pattern[0].pattern_slices->elts;
+    pattern_slice = rule->pattern[0].u.pattern_slices->elts;
     https = (pattern_slice->length == nxt_length("https"));
     tls = (r->tls != NULL);
 
@@ -2337,7 +2388,7 @@ static nxt_int_t
 nxt_http_route_test_cookie(nxt_http_request_t *r,
     nxt_http_route_rule_t *rule, nxt_array_t *array)
 {
-    nxt_bool_t             ret;
+    nxt_int_t              ret;
     nxt_http_name_value_t  *nv, *end;
 
     ret = 0;
@@ -2353,6 +2404,10 @@ nxt_http_route_test_cookie(nxt_http_request_t *r,
         {
             ret = nxt_http_route_test_rule(r, rule, nv->value,
                                            nv->value_length);
+            if (nxt_slow_path(ret == NXT_ERROR)) {
+                return NXT_ERROR;
+            }
+
             if (ret == 0) {
                 break;
             }
@@ -2378,6 +2433,9 @@ nxt_http_route_test_rule(nxt_http_request_t *r, nxt_http_route_rule_t *rule,
 
     while (pattern < end) {
         ret = nxt_http_route_pattern(r, pattern, start, length);
+        if (nxt_slow_path(ret == NXT_ERROR)) {
+            return NXT_ERROR;
+        }
 
         /* nxt_http_route_pattern() returns either 1 or 0. */
         ret ^= pattern->negative;
@@ -2403,11 +2461,26 @@ nxt_http_route_pattern(nxt_http_request_t *r, nxt_http_route_pattern_t *pattern,
     nxt_array_t                     *pattern_slices;
     nxt_http_route_pattern_slice_t  *pattern_slice;
 
+#if (NXT_HAVE_REGEX)
+    if (pattern->regex) {
+        if (r->regex_match == NULL) {
+            r->regex_match = nxt_regex_match_create(r->mem_pool, 0);
+            if (nxt_slow_path(r->regex_match == NULL)) {
+                return NXT_ERROR;
+            }
+        }
+
+        return nxt_regex_match(pattern->u.regex, start, length, r->regex_match);
+    }
+#endif
+
     if (length < pattern->min_length) {
         return 0;
     }
 
-    pattern_slices = pattern->pattern_slices;
+    nxt_assert(pattern->u.pattern_slices != NULL);
+
+    pattern_slices = pattern->u.pattern_slices;
     pattern_slice = pattern_slices->elts;
     end = start + length;
 
diff --git a/src/nxt_pcre.c b/src/nxt_pcre.c
new file mode 100644
index 00000000..737fc7cf
--- /dev/null
+++ b/src/nxt_pcre.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) Axel Duch
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+#include <nxt_regex.h>
+#include <pcre.h>
+
+
+struct nxt_regex_s {
+    pcre        *code;
+    pcre_extra  *extra;
+    nxt_str_t   pattern;
+};
+
+struct nxt_regex_match_s {
+    int  ovecsize;
+    int  ovec[];
+};
+
+
+static void *nxt_pcre_malloc(size_t size);
+static void nxt_pcre_free(void *p);
+
+static nxt_mp_t  *nxt_pcre_mp;
+
+
+nxt_regex_t *
+nxt_regex_compile(nxt_mp_t *mp, nxt_str_t *source, nxt_regex_err_t *err)
+{
+    int          erroffset;
+    char         *pattern;
+    void         *saved_malloc, *saved_free;
+    nxt_regex_t  *re;
+
+    err->offset = source->length;
+
+    re = nxt_mp_get(mp, sizeof(nxt_regex_t) + source->length + 1);
+    if (nxt_slow_path(re == NULL)) {
+        err->msg = "memory allocation failed";
+        return NULL;
+    }
+
+    pattern = nxt_pointer_to(re, sizeof(nxt_regex_t));
+
+    nxt_memcpy(pattern, source->start, source->length);
+    pattern[source->length] = '\0';
+
+    re->pattern.length = source->length;
+    re->pattern.start = (u_char *) pattern;
+
+    saved_malloc = pcre_malloc;
+    saved_free = pcre_free;
+
+    pcre_malloc = nxt_pcre_malloc;
+    pcre_free = nxt_pcre_free;
+    nxt_pcre_mp = mp;
+
+    re->code = pcre_compile(pattern, 0, &err->msg, &erroffset, NULL);
+    if (nxt_fast_path(re->code != NULL)) {
+#if 0
+        re->extra = pcre_study(re->code, PCRE_STUDY_JIT_COMPILE, &err->msg);
+        if (nxt_slow_path(re->extra == NULL && err->msg != NULL)) {
+            nxt_log_warn(thr->log, "pcre_study(%V) failed: %s", source, err->msg);
+        }
+#else
+        re->extra = NULL;
+#endif
+
+    } else {
+        err->offset = erroffset;
+        re = NULL;
+    }
+
+    pcre_malloc = saved_malloc;
+    pcre_free = saved_free;
+
+    return re;
+}
+
+
+static void*
+nxt_pcre_malloc(size_t size)
+{
+    if (nxt_slow_path(nxt_pcre_mp == NULL)) {
+        nxt_thread_log_alert("pcre_malloc(%uz) called without memory pool",
+                             size);
+        return NULL;
+    }
+
+    nxt_thread_log_debug("pcre_malloc(%uz), pool %p", size, nxt_pcre_mp);
+
+    return nxt_mp_get(nxt_pcre_mp, size);
+}
+
+
+static void
+nxt_pcre_free(void *p)
+{
+}
+
+
+nxt_regex_match_t *
+nxt_regex_match_create(nxt_mp_t *mp, size_t size)
+{
+    nxt_regex_match_t  *match;
+
+    match = nxt_mp_get(mp, sizeof(nxt_regex_match_t) + sizeof(int) * size);
+    if (nxt_fast_path(match != NULL)) {
+        match->ovecsize = size;
+    }
+
+    return match;
+}
+
+
+nxt_int_t
+nxt_regex_match(nxt_regex_t *re, u_char *subject, size_t length,
+    nxt_regex_match_t *match)
+{
+    int  ret;
+
+    ret = pcre_exec(re->code, re->extra, (const char *) subject, length, 0, 0,
+                    match->ovec, match->ovecsize);
+    if (nxt_slow_path(ret < PCRE_ERROR_NOMATCH)) {
+        nxt_thread_log_error(NXT_LOG_ERR,
+                             "pcre_exec() failed: %d on \"%*s\" using \"%V\"",
+                             ret, length, subject, &re->pattern);
+
+        return NXT_ERROR;
+    }
+
+    return (ret != PCRE_ERROR_NOMATCH);
+}
diff --git a/src/nxt_pcre2.c b/src/nxt_pcre2.c
new file mode 100644
index 00000000..22c4d2d4
--- /dev/null
+++ b/src/nxt_pcre2.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) Axel Duch
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+#include <nxt_regex.h>
+
+#define PCRE2_CODE_UNIT_WIDTH 8
+#include <pcre2.h>
+
+
+static void *nxt_pcre2_malloc(PCRE2_SIZE size, void *memory_data);
+static void nxt_pcre2_free(void *p, void *memory_data);
+
+
+struct nxt_regex_s {
+    pcre2_code  *code;
+    nxt_str_t   pattern;
+};
+
+
+nxt_regex_t *
+nxt_regex_compile(nxt_mp_t *mp, nxt_str_t *source, nxt_regex_err_t *err)
+{
+    int                    errcode;
+    nxt_int_t              ret;
+    PCRE2_SIZE             erroffset;
+    nxt_regex_t            *re;
+    pcre2_general_context  *general_ctx;
+    pcre2_compile_context  *compile_ctx;
+
+    static const u_char    alloc_error[] = "memory allocation failed";
+
+    general_ctx = pcre2_general_context_create(nxt_pcre2_malloc,
+                                               nxt_pcre2_free, mp);
+    if (nxt_slow_path(general_ctx == NULL)) {
+        goto alloc_fail;
+    }
+
+    compile_ctx = pcre2_compile_context_create(general_ctx);
+    if (nxt_slow_path(compile_ctx == NULL)) {
+        goto alloc_fail;
+    }
+
+    re = nxt_mp_get(mp, sizeof(nxt_regex_t));
+    if (nxt_slow_path(re == NULL)) {
+        goto alloc_fail;
+    }
+
+    if (nxt_slow_path(nxt_str_dup(mp, &re->pattern, source) == NULL)) {
+        goto alloc_fail;
+    }
+
+    re->code = pcre2_compile((PCRE2_SPTR) source->start, source->length, 0,
+                             &errcode, &erroffset, compile_ctx);
+    if (nxt_slow_path(re->code == NULL)) {
+        err->offset = erroffset;
+
+        ret = pcre2_get_error_message(errcode, (PCRE2_UCHAR *) err->msg,
+                                      ERR_BUF_SIZE);
+        if (ret < 0) {
+            (void) nxt_sprintf(err->msg, err->msg + ERR_BUF_SIZE,
+                               "compilation failed with unknown "
+                               "error code: %d%Z", errcode);
+        }
+
+        return NULL;
+    }
+
+#if 0
+    errcode = pcre2_jit_compile(re, PCRE2_JIT_COMPLETE);
+    if (nxt_slow_path(errcode != 0 && errcode != PCRE2_ERROR_JIT_BADOPTION)) {
+        ret = pcre2_get_error_message(errcode, (PCRE2_UCHAR *) err->msg,
+                                      ERR_BUF_SIZE);
+        if (ret < 0) {
+            (void) nxt_sprintf(err->msg, err->msg + ERR_BUF_SIZE,
+                               "JIT compilation failed with unknown "
+                               "error code: %d%Z", errcode);
+        }
+
+        return NULL;
+    }
+#endif
+
+    return re;
+
+alloc_fail:
+
+    err->offset = source->length;
+    nxt_memcpy(err->msg, alloc_error, sizeof(alloc_error));
+
+    return NULL;
+}
+
+
+static void *
+nxt_pcre2_malloc(PCRE2_SIZE size, void *mp)
+{
+    return nxt_mp_get(mp, size);
+}
+
+
+static void
+nxt_pcre2_free(void *p, void *mp)
+{
+}
+
+
+nxt_regex_match_t *
+nxt_regex_match_create(nxt_mp_t *mp, size_t size)
+{
+    nxt_regex_match_t      *match;
+    pcre2_general_context  *ctx;
+
+    ctx = pcre2_general_context_create(nxt_pcre2_malloc, nxt_pcre2_free, mp);
+    if (nxt_slow_path(ctx == NULL)) {
+        nxt_thread_log_alert("pcre2_general_context_create() failed");
+        return NULL;
+    }
+
+    match = pcre2_match_data_create(size, ctx);
+    if (nxt_slow_path(match == NULL)) {
+        nxt_thread_log_alert("pcre2_match_data_create(%uz) failed", size);
+        return NULL;
+    }
+
+    return match;
+}
+
+
+nxt_int_t
+nxt_regex_match(nxt_regex_t *re, u_char *subject, size_t length,
+    nxt_regex_match_t *match)
+{
+    nxt_int_t    ret;
+    PCRE2_UCHAR  errptr[ERR_BUF_SIZE];
+
+    ret = pcre2_match(re->code, (PCRE2_SPTR) subject, length, 0, 0, match,
+                      NULL);
+
+    if (nxt_slow_path(ret < PCRE2_ERROR_NOMATCH)) {
+
+        if (pcre2_get_error_message(ret, errptr, ERR_BUF_SIZE) < 0) {
+            nxt_thread_log_error(NXT_LOG_ERR,
+                                 "pcre2_match() failed: %d on \"%*s\" "
+                                 "using \"%V\"", ret, subject, length, subject,
+                                 &re->pattern);
+
+        } else {
+            nxt_thread_log_error(NXT_LOG_ERR,
+                                 "pcre2_match() failed: %s (%d) on \"%*s\" "
+                                 "using \"%V\"", errptr, ret, length, subject,
+                                 &re->pattern);
+        }
+
+        return NXT_ERROR;
+    }
+
+    return (ret != PCRE2_ERROR_NOMATCH);
+}
diff --git a/src/nxt_regex.h b/src/nxt_regex.h
new file mode 100644
index 00000000..a24c50f8
--- /dev/null
+++ b/src/nxt_regex.h
@@ -0,0 +1,41 @@
+
+/*
+ * Copyright (C) Axel Duch
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef _NXT_REGEX_H_INCLUDED_
+#define _NXT_REGEX_H_INCLUDED_
+
+#if (NXT_HAVE_REGEX)
+
+typedef struct nxt_regex_s        nxt_regex_t;
+
+ #if (NXT_HAVE_PCRE2)
+typedef void                      nxt_regex_match_t;
+#else
+typedef struct nxt_regex_match_s  nxt_regex_match_t;
+#endif
+
+typedef struct {
+    size_t      offset;
+
+#if (NXT_HAVE_PCRE2)
+#define ERR_BUF_SIZE  256
+    u_char      msg[ERR_BUF_SIZE];
+#else
+    const char  *msg;
+#endif
+} nxt_regex_err_t;
+
+
+NXT_EXPORT void nxt_regex_init(void);
+NXT_EXPORT nxt_regex_t *nxt_regex_compile(nxt_mp_t *mp, nxt_str_t *source,
+    nxt_regex_err_t *err);
+NXT_EXPORT nxt_regex_match_t *nxt_regex_match_create(nxt_mp_t *mp, size_t size);
+NXT_EXPORT nxt_int_t nxt_regex_match(nxt_regex_t *re, u_char *subject,
+    size_t length, nxt_regex_match_t *match);
+
+#endif /* NXT_HAVE_REGEX */
+
+#endif /* _NXT_REGEX_H_INCLUDED_ */
diff --git a/src/nxt_runtime.c b/src/nxt_runtime.c
index 44970b34..d9d986da 100644
--- a/src/nxt_runtime.c
+++ b/src/nxt_runtime.c
@@ -10,6 +10,7 @@
 #include <nxt_port.h>
 #include <nxt_main_process.h>
 #include <nxt_router.h>
+#include <nxt_regex.h>
 
 
 static nxt_int_t nxt_runtime_inherited_listen_sockets(nxt_task_t *task,
@@ -702,9 +703,6 @@ nxt_runtime_thread_pool_destroy(nxt_task_t *task, nxt_runtime_t *rt,
 static void
 nxt_runtime_thread_pool_init(void)
 {
-#if (NXT_REGEX)
-    nxt_regex_init(0);
-#endif
 }
 
 
diff --git a/test/test_routing.py b/test/test_routing.py
index 9e0f52dc..83852273 100644
--- a/test/test_routing.py
+++ b/test/test_routing.py
@@ -230,6 +230,48 @@ class TestRouting(TestApplicationProto):
         assert self.get(url='/aBCaBbc')['status'] == 200
         assert self.get(url='/ABc')['status'] == 404
 
+    def test_routes_empty_regex(self):
+        self.route_match({"uri":"~"})
+        assert self.get(url='/')['status'] == 200, 'empty regexp'
+        assert self.get(url='/anything')['status'] == 200, '/anything'
+
+        self.route_match({"uri":"!~"})
+        assert self.get(url='/')['status'] == 404, 'empty regexp 2'
+        assert self.get(url='/nothing')['status'] == 404, '/nothing'
+
+    def test_routes_bad_regex(self):
+        assert 'error' in self.route(
+            {"match": {"uri": "~/bl[ah"}, "action": {"return": 200}}
+        ), 'bad regex'
+
+        status = self.route(
+            {"match": {"uri": "~(?R)?z"}, "action": {"return": 200}}
+        )
+        if 'error' not in status:
+            assert self.get(url='/nothing_z')['status'] == 500, '/nothing_z'
+
+        status = self.route(
+            {"match": {"uri": "~((?1)?z)"}, "action": {"return": 200}}
+        )
+        if 'error' not in status:
+            assert self.get(url='/nothing_z')['status'] == 500, '/nothing_z'
+
+    def test_routes_match_regex_case_sensitive(self):
+        self.route_match({"uri": "~/bl[ah]"})
+
+        assert self.get(url='/rlah')['status'] == 404, '/rlah'
+        assert self.get(url='/blah')['status'] == 200, '/blah'
+        assert self.get(url='/blh')['status'] == 200, '/blh'
+        assert self.get(url='/BLAH')['status'] == 404, '/BLAH'
+
+    def test_routes_match_regex_negative_case_sensitive(self):
+        self.route_match({"uri": "!~/bl[ah]"})
+
+        assert self.get(url='/rlah')['status'] == 200, '/rlah'
+        assert self.get(url='/blah')['status'] == 404, '/blah'
+        assert self.get(url='/blh')['status'] == 404, '/blh'
+        assert self.get(url='/BLAH')['status'] == 200, '/BLAH'
+
     def test_routes_pass_encode(self):
         def check_pass(path, name):
             assert 'success' in self.conf(