ucm: configuration - add DefineRegex

Syntax:

  DefineRegex.VariableName {
    String "something to match"
    Regex "(me)thi(ng)"
  }

Result:

- configuration variable "VariableName" is equal to "mething"
- configuration variable "VariableName1" is equal to "me"
- configuration variable "VariableName2" is equal to "ng"

Notes:

The "Flags" string in the DefineRegex compound may specify
the compilation flags (e = extended, i = ignore case,
s = no substitutes, n = newline). See 'man 3 regex' for
more details.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/ucm/Makefile.am b/src/ucm/Makefile.am
index 416db22..feb3c0c 100644 (file)
--- a/src/ucm/Makefile.am
+++ b/src/ucm/Makefile.am
@@ -1,6 +1,7 @@
 EXTRA_LTLIBRARIES = libucm.la
 
-libucm_la_SOURCES = utils.c parser.c ucm_cond.c ucm_subs.c ucm_include.c main.c
+libucm_la_SOURCES = utils.c parser.c ucm_cond.c ucm_subs.c ucm_include.c \
+                   ucm_regex.c main.c
 
 noinst_HEADERS = ucm_local.h
 

diff --git a/src/ucm/parser.c b/src/ucm/parser.c
index 7cc0937..ef96a96 100644 (file)
--- a/src/ucm/parser.c
+++ b/src/ucm/parser.c
@@ -194,6 +194,42 @@ int parse_get_safe_id(snd_config_t *n, const char **id)
 }
 
 /*
+ * Evaluate variable regex definitions (in-place delete)
+ */
+static int evaluate_regex(snd_use_case_mgr_t *uc_mgr,
+                         snd_config_t *cfg)
+{
+       snd_config_iterator_t i, next;
+       snd_config_t *d, *n;
+       const char *id;
+       int err;
+
+       err = snd_config_search(cfg, "DefineRegex", &d);
+       if (err == -ENOENT)
+               return 1;
+       if (err < 0)
+               return err;
+
+       if (snd_config_get_type(d) != SND_CONFIG_TYPE_COMPOUND) {
+               uc_error("compound type expected for DefineRegex");
+               return -EINVAL;
+       }
+
+       snd_config_for_each(i, next, d) {
+               n = snd_config_iterator_entry(i);
+               err = snd_config_get_id(n, &id);
+               if (err < 0)
+                       return err;
+               err = uc_mgr_define_regex(uc_mgr, id, n);
+               if (err < 0)
+                       return err;
+       }
+
+       snd_config_delete(d);
+       return 0;
+}
+
+/*
  * Evaluate variable definitions (in-place delete)
  */
 static int evaluate_define(snd_use_case_mgr_t *uc_mgr,
@@ -207,7 +243,7 @@ static int evaluate_define(snd_use_case_mgr_t *uc_mgr,
 
        err = snd_config_search(cfg, "Define", &d);
        if (err == -ENOENT)
-               return 1;
+               return evaluate_regex(uc_mgr, cfg);
        if (err < 0)
                return err;
 
@@ -233,7 +269,8 @@ static int evaluate_define(snd_use_case_mgr_t *uc_mgr,
        }
 
        snd_config_delete(d);
-       return 0;
+
+       return evaluate_regex(uc_mgr, cfg);
 }
 
 /*

diff --git a/src/ucm/ucm_local.h b/src/ucm/ucm_local.h
index 2aea43e..25a50b4 100644 (file)
--- a/src/ucm/ucm_local.h
+++ b/src/ucm/ucm_local.h
@@ -317,6 +317,10 @@ int uc_mgr_evaluate_condition(snd_use_case_mgr_t *uc_mgr,
                              snd_config_t *parent,
                              snd_config_t *cond);
 
+int uc_mgr_define_regex(snd_use_case_mgr_t *uc_mgr,
+                       const char *name,
+                       snd_config_t *eval);
+
 /** The name of the environment variable containing the UCM directory */
 #define ALSA_CONFIG_UCM_VAR "ALSA_CONFIG_UCM"
 

diff --git a/src/ucm/ucm_regex.c b/src/ucm/ucm_regex.c
new file mode 100644 (file)
index 0000000..be8f277
--- /dev/null
+++ b/src/ucm/ucm_regex.c
@@ -0,0 +1,174 @@
+/*
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *  Support for the verb/device/modifier core logic and API,
+ *  command line tool and file parser was kindly sponsored by
+ *  Texas Instruments Inc.
+ *  Support for multiple active modifiers and devices,
+ *  transition sequences, multiple client access and user defined use
+ *  cases was kindly sponsored by Wolfson Microelectronics PLC.
+ *
+ *  Copyright (C) 2019 Red Hat Inc.
+ *  Authors: Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include "ucm_local.h"
+#include <ctype.h>
+#include <regex.h>
+
+static int get_string(snd_config_t *compound, const char *key, const char **str)
+{
+       snd_config_t *node;
+       int err;
+
+       err = snd_config_search(compound, key, &node);
+       if (err < 0)
+               return err;
+       return snd_config_get_string(node, str);
+}
+
+static char *extract_substring(const char *data, regmatch_t *match)
+{
+       char *s;
+       size_t len;
+
+       len = match->rm_eo - match->rm_so;
+       s = malloc(len + 1);
+       if (s == NULL)
+               return NULL;
+       memcpy(s, data + match->rm_so, len);
+       s[len] = '\0';
+       return s;
+}
+
+static int set_variables(snd_use_case_mgr_t *uc_mgr, const char *data,
+                        unsigned int match_size, regmatch_t *match,
+                        const char *name)
+{
+       size_t name2_len = strlen(name) + 16;
+       char *name2 = alloca(name2_len);
+       char *s;
+       unsigned int i;
+       int err;
+
+       if (match[0].rm_so < 0 || match[0].rm_eo < 0)
+               return 0;
+       s = extract_substring(data, &match[0]);
+       if (s == NULL)
+               return -ENOMEM;
+       err = uc_mgr_set_variable(uc_mgr, name, s);
+       free(s);
+       if (err < 0)
+               return err;
+       for (i = 1; i < match_size; i++) {
+               if (match[0].rm_so < 0 || match[0].rm_eo < 0)
+                       return 0;
+               s = extract_substring(data, &match[i]);
+               if (s == NULL)
+                       return -ENOMEM;
+               snprintf(name2, name2_len, "%s%u", name, i);
+               err = uc_mgr_set_variable(uc_mgr, name2, s);
+               free(s);
+               if (err < 0)
+                       return err;
+       }
+       return 0;
+}
+
+int uc_mgr_define_regex(snd_use_case_mgr_t *uc_mgr, const char *name,
+                       snd_config_t *eval)
+{
+       const char *string, *regex_string, *flags_string;
+       char *s;
+       regex_t re;
+       int options = 0;
+       regmatch_t match[20];
+       int err;
+
+       if (uc_mgr->conf_format < 3) {
+               uc_error("define regex is supported in v3+ syntax");
+               return -EINVAL;
+       }
+
+       if (snd_config_get_type(eval) != SND_CONFIG_TYPE_COMPOUND) {
+               uc_error("compound type expected for DefineRegex");
+               return -EINVAL;
+       }
+
+       err = get_string(eval, "String", &string);
+       if (err < 0) {
+               uc_error("DefineRegex error (String)");
+               return -EINVAL;
+       }
+
+       err = get_string(eval, "Regex", &regex_string);
+       if (err < 0) {
+               uc_error("DefineRegex error (Regex string)");
+               return -EINVAL;
+       }
+
+       err = get_string(eval, "Flags", &flags_string);
+       if (err == -ENOENT) {
+               options = REG_EXTENDED;
+       } else if (err < 0) {
+               uc_error("DefineRegex error (Flags string)");
+               return -EINVAL;
+       } else {
+               while (*flags_string) {
+                       switch (tolower(*flags_string)) {
+                       case 'e':
+                               options |= REG_EXTENDED;
+                               break;
+                       case 'i':
+                               options |= REG_ICASE;
+                               break;
+                       case 's':
+                               options |= REG_NOSUB;
+                               break;
+                       case 'n':
+                               options |= REG_NEWLINE;
+                               break;
+                       default:
+                               uc_error("DefineRegex error (unknown flag '%c')", *flags_string);
+                               return -EINVAL;
+                       }
+                       flags_string++;
+               }
+       }
+
+       err = uc_mgr_get_substituted_value(uc_mgr, &s, regex_string);
+       if (err < 0)
+               return err;
+       err = regcomp(&re, s, options);
+       free(s);
+       if (err) {
+               uc_error("Regex '%s' compilation failed (code %d)", err);
+               return -EINVAL;
+       }
+
+       err = uc_mgr_get_substituted_value(uc_mgr, &s, string);
+       if (err < 0) {
+               regfree(&re);
+               return err;
+       }
+       err = regexec(&re, s, ARRAY_SIZE(match), match, 0);
+       if (err < 0)
+               err = -errno;
+       else
+               err = set_variables(uc_mgr, s, ARRAY_SIZE(match), match, name);
+       free(s);
+       regfree(&re);
+       return err;
+}