Move the lttng::free util under the lttng::memory namespace
[lttng-tools.git] / src / bin / lttng / commands / enable_events.cpp
index a2db2cbc22884f3a51c2c1355e42478075deb2d3..b081adeeed7f3f68d7d97f57722002091c40bef0 100644 (file)
@@ -6,57 +6,77 @@
  */
 
 #define _LGPL_SOURCE
+#include <common/compat/getenv.hpp>
+#include <common/compat/string.hpp>
+#include <common/make-unique-wrapper.hpp>
+#include <common/scope-exit.hpp>
+#include <common/sessiond-comm/sessiond-comm.hpp>
+#include <common/string-utils/string-utils.hpp>
+#include <common/utils.hpp>
+
+#include <ctype.h>
+#include <inttypes.h>
 #include <popt.h>
+#include <sstream>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <inttypes.h>
-#include <ctype.h>
-
-#include <common/sessiond-comm/sessiond-comm.h>
-#include <common/compat/string.h>
-#include <common/compat/getenv.h>
-#include <common/string-utils/string-utils.h>
-#include <common/utils.h>
+#include <vector>
 
 /* Mi dependancy */
-#include <common/mi-lttng.h>
+#include "../command.hpp"
+#include "../loglevel.hpp"
+#include "../uprobe.hpp"
 
-#include <lttng/domain-internal.h>
-#include <lttng/event-internal.h>
+#include <common/mi-lttng.hpp>
 
-#include "../command.h"
-#include "../loglevel.h"
-#include "../uprobe.h"
+#include <lttng/domain-internal.hpp>
+#include <lttng/event-internal.hpp>
 
 #if (LTTNG_SYMBOL_NAME_LEN == 256)
-#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API    "255"
+#define LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "255"
 #endif
 
-static char *opt_event_list;
-static int opt_event_type;
-static const char *opt_loglevel;
-static int opt_loglevel_type;
-static int opt_kernel;
-static char *opt_session_name;
-static int opt_userspace;
-static int opt_jul;
-static int opt_log4j;
-static int opt_python;
-static int opt_enable_all;
-static char *opt_probe;
-static char *opt_userspace_probe;
-static char *opt_function;
-static char *opt_channel_name;
-static char *opt_filter;
-static char *opt_exclude;
+namespace {
+void _mi_lttng_writer_deleter_func(mi_writer *writer)
+{
+       if (writer && mi_lttng_writer_destroy(writer)) {
+               LTTNG_THROW_ERROR("Failed to destroy mi_writer instance");
+       }
+}
+
+using mi_writer_uptr = std::unique_ptr<
+       mi_writer,
+       lttng::memory::create_deleter_class<mi_writer, _mi_lttng_writer_deleter_func>::deleter>;
+using event_rule_patterns = std::vector<std::string>;
+
+int opt_event_type;
+const char *opt_loglevel;
+int opt_loglevel_type;
+int opt_kernel;
+char *opt_session_name;
+int opt_userspace;
+int opt_jul;
+int opt_log4j;
+int opt_python;
+int opt_enable_all;
+char *opt_probe;
+char *opt_userspace_probe;
+char *opt_function;
+char *opt_channel_name;
+char *opt_filter;
+char *opt_exclude;
+
+struct lttng_handle *handle;
+mi_writer_uptr writer;
 
 #ifdef LTTNG_EMBED_HELP
 static const char help_msg[] =
 #include <lttng-enable-event.1.h>
-;
+       ;
 #endif
 
 enum {
@@ -74,52 +94,58 @@ enum {
        OPT_EXCLUDE,
 };
 
-static struct lttng_handle *handle;
-static struct mi_writer *writer;
-
-static struct poptOption long_options[] = {
+struct poptOption long_options[] = {
        /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
-       {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
-       {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
-       {"all",            'a', POPT_ARG_VAL, &opt_enable_all, 1, 0, 0},
-       {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
-       {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
-       {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
-       {"jul",            'j', POPT_ARG_VAL, &opt_jul, 1, 0, 0},
-       {"log4j",          'l', POPT_ARG_VAL, &opt_log4j, 1, 0, 0},
-       {"python",         'p', POPT_ARG_VAL, &opt_python, 1, 0, 0},
-       {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
-       {"probe",          0,   POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
-       {"userspace-probe",0,   POPT_ARG_STRING, &opt_userspace_probe, OPT_USERSPACE_PROBE, 0, 0},
-       {"function",       0,   POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
-       {"syscall",        0,   POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
-       {"loglevel",       0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL, 0, 0},
-       {"loglevel-only",  0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL_ONLY, 0, 0},
-       {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
-       {"filter",         'f', POPT_ARG_STRING, &opt_filter, OPT_FILTER, 0, 0},
-       {"exclude",        'x', POPT_ARG_STRING, &opt_exclude, OPT_EXCLUDE, 0, 0},
-       {0, 0, 0, 0, 0, 0, 0}
+       { "help", 'h', POPT_ARG_NONE, nullptr, OPT_HELP, nullptr, nullptr },
+       { "session", 's', POPT_ARG_STRING, &opt_session_name, 0, nullptr, nullptr },
+       { "all", 'a', POPT_ARG_VAL, &opt_enable_all, 1, nullptr, nullptr },
+       { "channel", 'c', POPT_ARG_STRING, &opt_channel_name, 0, nullptr, nullptr },
+       { "kernel", 'k', POPT_ARG_VAL, &opt_kernel, 1, nullptr, nullptr },
+       { "userspace", 'u', POPT_ARG_NONE, nullptr, OPT_USERSPACE, nullptr, nullptr },
+       { "jul", 'j', POPT_ARG_VAL, &opt_jul, 1, nullptr, nullptr },
+       { "log4j", 'l', POPT_ARG_VAL, &opt_log4j, 1, nullptr, nullptr },
+       { "python", 'p', POPT_ARG_VAL, &opt_python, 1, nullptr, nullptr },
+       { "tracepoint", 0, POPT_ARG_NONE, nullptr, OPT_TRACEPOINT, nullptr, nullptr },
+       { "probe", 0, POPT_ARG_STRING, &opt_probe, OPT_PROBE, nullptr, nullptr },
+       { "userspace-probe",
+         0,
+         POPT_ARG_STRING,
+         &opt_userspace_probe,
+         OPT_USERSPACE_PROBE,
+         nullptr,
+         nullptr },
+       { "function", 0, POPT_ARG_STRING, &opt_function, OPT_FUNCTION, nullptr, nullptr },
+       { "syscall", 0, POPT_ARG_NONE, nullptr, OPT_SYSCALL, nullptr, nullptr },
+       { "loglevel", 0, POPT_ARG_STRING, nullptr, OPT_LOGLEVEL, nullptr, nullptr },
+       { "loglevel-only", 0, POPT_ARG_STRING, nullptr, OPT_LOGLEVEL_ONLY, nullptr, nullptr },
+       { "list-options", 0, POPT_ARG_NONE, nullptr, OPT_LIST_OPTIONS, nullptr, nullptr },
+       { "filter", 'f', POPT_ARG_STRING, &opt_filter, OPT_FILTER, nullptr, nullptr },
+       { "exclude", 'x', POPT_ARG_STRING, &opt_exclude, OPT_EXCLUDE, nullptr, nullptr },
+       { nullptr, 0, 0, nullptr, 0, nullptr, nullptr }
 };
 
 /*
  * Parse probe options.
  */
-static int parse_probe_opts(struct lttng_event *ev, char *opt)
+int parse_probe_opts(struct lttng_event *ev, char *opt)
 {
        int ret = CMD_SUCCESS;
        int match;
        char s_hex[19];
-#define S_HEX_LEN_SCANF_IS_A_BROKEN_API "18"   /* 18 is (19 - 1) (\0 is extra) */
+#define S_HEX_LEN_SCANF_IS_A_BROKEN_API "18" /* 18 is (19 - 1) (\0 is extra) */
        char name[LTTNG_SYMBOL_NAME_LEN];
 
-       if (opt == NULL) {
+       if (opt == nullptr) {
                ret = CMD_ERROR;
                goto end;
        }
 
        /* Check for symbol+offset */
-       match = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API
-                       "[^'+']+%" S_HEX_LEN_SCANF_IS_A_BROKEN_API "s", name, s_hex);
+       match = sscanf(opt,
+                      "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API
+                      "[^'+']+%" S_HEX_LEN_SCANF_IS_A_BROKEN_API "s",
+                      name,
+                      s_hex);
        if (match == 2) {
                strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
                ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
@@ -129,7 +155,7 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
                        ret = CMD_ERROR;
                        goto end;
                }
-               ev->attr.probe.offset = strtoull(s_hex, NULL, 0);
+               ev->attr.probe.offset = strtoull(s_hex, nullptr, 0);
                DBG("probe offset %" PRIu64, ev->attr.probe.offset);
                ev->attr.probe.addr = 0;
                goto end;
@@ -137,8 +163,7 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
 
        /* Check for symbol */
        if (isalpha(name[0]) || name[0] == '_') {
-               match = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "s",
-                       name);
+               match = sscanf(opt, "%" LTTNG_SYMBOL_NAME_LEN_SCANF_IS_A_BROKEN_API "s", name);
                if (match == 1) {
                        strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
                        ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
@@ -159,11 +184,11 @@ static int parse_probe_opts(struct lttng_event *ev, char *opt)
                 * is in hexadecimal and can be 1 to 9 if it's in decimal.
                 */
                if (*s_hex == '\0' || !isdigit(*s_hex)) {
-                       ERR("Invalid probe description %s", s_hex);
+                       ERR("Invalid probe description `%s`", s_hex);
                        ret = CMD_ERROR;
                        goto end;
                }
-               ev->attr.probe.addr = strtoull(s_hex, NULL, 0);
+               ev->attr.probe.addr = strtoull(s_hex, nullptr, 0);
                DBG("probe addr %" PRIu64, ev->attr.probe.addr);
                ev->attr.probe.offset = 0;
                memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
@@ -177,22 +202,19 @@ end:
        return ret;
 }
 
-static
 const char *print_channel_name(const char *name)
 {
-       return name ? : DEFAULT_CHANNEL_NAME;
+       return name ?: DEFAULT_CHANNEL_NAME;
 }
 
-static
 const char *print_raw_channel_name(const char *name)
 {
-       return name ? : "<default>";
+       return name ?: "<default>";
 }
 
 /*
  * Mi print exlcusion list
  */
-static
 int mi_print_exclusion(const struct lttng_dynamic_pointer_array *exclusions)
 {
        int ret;
@@ -206,24 +228,24 @@ int mi_print_exclusion(const struct lttng_dynamic_pointer_array *exclusions)
                goto end;
        }
 
-       ret = mi_lttng_writer_open_element(writer, config_element_exclusions);
+       ret = mi_lttng_writer_open_element(writer.get(), config_element_exclusions);
        if (ret) {
                goto end;
        }
 
        for (i = 0; i < count; i++) {
-               const char *exclusion = (const char *) lttng_dynamic_pointer_array_get_pointer(
-                               exclusions, i);
+               const char *exclusion =
+                       (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions, i);
 
-               ret = mi_lttng_writer_write_element_string(writer,
-                               config_element_exclusion, exclusion);
+               ret = mi_lttng_writer_write_element_string(
+                       writer.get(), config_element_exclusion, exclusion);
                if (ret) {
                        goto end;
                }
        }
 
        /* Close exclusions element */
-       ret = mi_lttng_writer_close_element(writer);
+       ret = mi_lttng_writer_close_element(writer.get());
 
 end:
        return ret;
@@ -232,7 +254,6 @@ end:
 /*
  * Return allocated string for pretty-printing exclusion names.
  */
-static
 char *print_exclusions(const struct lttng_dynamic_pointer_array *exclusions)
 {
        int length = 0;
@@ -247,26 +268,26 @@ char *print_exclusions(const struct lttng_dynamic_pointer_array *exclusions)
 
        /* Calculate total required length. */
        for (i = 0; i < count; i++) {
-               const char *exclusion = (const char *) lttng_dynamic_pointer_array_get_pointer(
-                               exclusions, i);
+               const char *exclusion =
+                       (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions, i);
 
                length += strlen(exclusion) + 4;
        }
 
        length += sizeof(preamble);
-       ret = (char *) zmalloc(length);
+       ret = calloc<char>(length);
        if (!ret) {
-               return NULL;
+               return nullptr;
        }
 
        strncpy(ret, preamble, length);
        for (i = 0; i < count; i++) {
-               const char *exclusion = (const char *) lttng_dynamic_pointer_array_get_pointer(
-                               exclusions, i);
+               const char *exclusion =
+                       (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions, i);
 
-               strcat(ret, "\"");
+               strcat(ret, "`");
                strcat(ret, exclusion);
-               strcat(ret, "\"");
+               strcat(ret, "`");
                if (i != count - 1) {
                        strcat(ret, ", ");
                }
@@ -275,12 +296,11 @@ char *print_exclusions(const struct lttng_dynamic_pointer_array *exclusions)
        return ret;
 }
 
-static
-int check_exclusion_subsets(const char *event_name, const char *exclusion)
+int check_exclusion_subsets(const char *pattern, const char *exclusion)
 {
        bool warn = false;
        int ret = 0;
-       const char *e = event_name;
+       const char *e = pattern;
        const char *x = exclusion;
 
        /* Scan both the excluder and the event letter by letter */
@@ -298,8 +318,9 @@ int check_exclusion_subsets(const char *event_name, const char *exclusion)
 
                if (*x == '*') {
                        /* Event is a subset of the excluder */
-                       ERR("Event %s: %s excludes all events from %s",
-                               event_name, exclusion, event_name);
+                       ERR("Exclusion pattern `%s` excludes all events from `%s`",
+                           exclusion,
+                           pattern);
                        goto error;
                }
 
@@ -311,7 +332,7 @@ int check_exclusion_subsets(const char *event_name, const char *exclusion)
                        goto end;
                }
 
-cmp_chars:
+       cmp_chars:
                if (*x != *e) {
                        warn = true;
                        break;
@@ -328,63 +349,17 @@ error:
 
 end:
        if (warn) {
-               WARN("Event %s: %s does not exclude any events from %s",
-                       event_name, exclusion, event_name);
-       }
-
-       return ret;
-}
-
-int validate_exclusion_list(const char *event_name,
-               const struct lttng_dynamic_pointer_array *exclusions)
-{
-       int ret;
-
-       /* Event name must be a valid globbing pattern to allow exclusions. */
-       if (!strutils_is_star_glob_pattern(event_name)) {
-               ERR("Event %s: Exclusions can only be used with a globbing pattern",
-                       event_name);
-               goto error;
-       }
-
-       /*
-        * If the event name is a star-at-end only globbing pattern,
-        * then we can validate the individual exclusions. Otherwise
-        * all exclusions are passed to the session daemon.
-        */
-       if (strutils_is_star_at_the_end_only_glob_pattern(event_name)) {
-               size_t i, num_exclusions;
-
-               num_exclusions = lttng_dynamic_pointer_array_get_count(exclusions);
-
-               for (i = 0; i < num_exclusions; i++) {
-                       const char *exclusion =
-                                       (const char *) lttng_dynamic_pointer_array_get_pointer(
-                                                       exclusions, i);
-
-                       if (!strutils_is_star_glob_pattern(exclusion) ||
-                                       strutils_is_star_at_the_end_only_glob_pattern(exclusion)) {
-                               ret = check_exclusion_subsets(event_name, exclusion);
-                               if (ret) {
-                                       goto error;
-                               }
-                       }
-               }
+               WARN("Exclusion pattern `%s` does not exclude any event from `%s`",
+                    exclusion,
+                    pattern);
        }
 
-       ret = 0;
-       goto end;
-
-error:
-       ret = -1;
-
-end:
        return ret;
 }
 
-static int create_exclusion_list_and_validate(const char *event_name,
-               const char *exclusions_arg,
-               struct lttng_dynamic_pointer_array *exclusions)
+int create_exclusion_list_and_validate(const char *pattern,
+                                      const char *exclusions_arg,
+                                      struct lttng_dynamic_pointer_array *exclusions)
 {
        int ret = 0;
 
@@ -394,8 +369,7 @@ static int create_exclusion_list_and_validate(const char *event_name,
                goto error;
        }
 
-       if (validate_exclusion_list(event_name, exclusions) !=
-                       0) {
+       if (validate_exclusion_list(pattern, exclusions) != 0) {
                goto error;
        }
 
@@ -409,18 +383,18 @@ end:
        return ret;
 }
 
-static void warn_on_truncated_exclusion_names(const struct lttng_dynamic_pointer_array *exclusions,
-       int *warn)
+void warn_on_truncated_exclusion_names(const struct lttng_dynamic_pointer_array *exclusions,
+                                      int *warn)
 {
        size_t i;
        const size_t num_exclusions = lttng_dynamic_pointer_array_get_count(exclusions);
 
        for (i = 0; i < num_exclusions; i++) {
-               const char * const exclusion = (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions, i);
+               const char *const exclusion =
+                       (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions, i);
 
                if (strlen(exclusion) >= LTTNG_SYMBOL_NAME_LEN) {
-                       WARN("Event exclusion \"%s\" will be truncated",
-                                       exclusion);
+                       WARN("Event exclusion \"%s\" will be truncated", exclusion);
                        *warn = 1;
                }
        }
@@ -430,17 +404,17 @@ static void warn_on_truncated_exclusion_names(const struct lttng_dynamic_pointer
  * Enabling event using the lttng API.
  * Note: in case of error only the last error code will be return.
  */
-static int enable_events(char *session_name)
+int enable_events(const std::string& session_name, const event_rule_patterns& patterns)
 {
        int ret = CMD_SUCCESS, command_ret = CMD_SUCCESS;
        int error_holder = CMD_SUCCESS, warn = 0, error = 0, success = 1;
-       char *event_name, *channel_name = NULL;
+       char *channel_name = nullptr;
        struct lttng_event *ev;
        struct lttng_domain dom = {};
        struct lttng_dynamic_pointer_array exclusions;
-       struct lttng_userspace_probe_location *uprobe_loc = NULL;
+       struct lttng_userspace_probe_location *uprobe_loc = nullptr;
 
-       lttng_dynamic_pointer_array_init(&exclusions, NULL);
+       lttng_dynamic_pointer_array_init(&exclusions, nullptr);
 
        ev = lttng_event_create();
        if (!ev) {
@@ -450,7 +424,7 @@ static int enable_events(char *session_name)
 
        if (opt_kernel) {
                if (opt_loglevel) {
-                       WARN("Kernel loglevels are not supported.");
+                       WARN("Kernel log levels are not supported");
                }
        }
 
@@ -485,8 +459,8 @@ static int enable_events(char *session_name)
                case LTTNG_DOMAIN_JUL:
                case LTTNG_DOMAIN_LOG4J:
                case LTTNG_DOMAIN_PYTHON:
-                       ERR("Event name exclusions are not yet implemented for %s events",
-                                       lttng_domain_type_str(dom.type));
+                       ERR("Event name exclusions are not supported for %s event rules",
+                           lttng_domain_type_str(dom.type));
                        ret = CMD_ERROR;
                        goto error;
                case LTTNG_DOMAIN_UST:
@@ -511,8 +485,8 @@ static int enable_events(char *session_name)
                case LTTNG_EVENT_PROBE:
                case LTTNG_EVENT_USERSPACE_PROBE:
                case LTTNG_EVENT_FUNCTION:
-                       ERR("Filter expressions are not supported for %s events",
-                                       get_event_type_str((lttng_event_type) opt_event_type));
+                       ERR("Filter expressions are not supported for %s event rules",
+                           get_event_type_str((lttng_event_type) opt_event_type));
                        ret = CMD_ERROR;
                        goto error;
                default:
@@ -523,8 +497,8 @@ static int enable_events(char *session_name)
 
        channel_name = opt_channel_name;
 
-       handle = lttng_create_handle(session_name, &dom);
-       if (handle == NULL) {
+       handle = lttng_create_handle(session_name.c_str(), &dom);
+       if (handle == nullptr) {
                ret = -1;
                goto error;
        }
@@ -532,303 +506,29 @@ static int enable_events(char *session_name)
        /* Prepare Mi */
        if (lttng_opt_mi) {
                /* Open a events element */
-               ret = mi_lttng_writer_open_element(writer, config_element_events);
+               ret = mi_lttng_writer_open_element(writer.get(), config_element_events);
                if (ret) {
                        ret = CMD_ERROR;
                        goto error;
                }
        }
 
-       if (opt_enable_all) {
-               /* Default setup for enable all */
-               if (opt_kernel) {
-                       ev->type = (lttng_event_type) opt_event_type;
-                       strcpy(ev->name, "*");
-                       /* kernel loglevels not implemented */
-                       ev->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
-               } else {
-                       ev->type = LTTNG_EVENT_TRACEPOINT;
-                       strcpy(ev->name, "*");
-                       ev->loglevel_type = (lttng_loglevel_type) opt_loglevel_type;
-                       if (opt_loglevel) {
-                               int name_search_ret;
-
-                               LTTNG_ASSERT(opt_userspace || opt_jul || opt_log4j || opt_python);
-
-                               if (opt_userspace) {
-                                       enum lttng_loglevel loglevel;
-
-                                       name_search_ret = loglevel_name_to_value(opt_loglevel, &loglevel);
-                                       ev->loglevel = (int) loglevel;
-                               } else if (opt_jul) {
-                                       enum lttng_loglevel_jul loglevel;
-
-                                       name_search_ret = loglevel_jul_name_to_value(opt_loglevel, &loglevel);
-                                       ev->loglevel = (int) loglevel;
-                               } else if (opt_log4j) {
-                                       enum lttng_loglevel_log4j loglevel;
-
-                                       name_search_ret = loglevel_log4j_name_to_value(opt_loglevel, &loglevel);
-                                       ev->loglevel = (int) loglevel;
-                               } else {
-                                       /* python domain. */
-                                       enum lttng_loglevel_python loglevel;
-
-                                       name_search_ret = loglevel_python_name_to_value(opt_loglevel, &loglevel);
-                                       ev->loglevel = (int) loglevel;
-                               }
-
-                               if (name_search_ret == -1) {
-                                       ERR("Unknown loglevel %s", opt_loglevel);
-                                       ret = -LTTNG_ERR_INVALID;
-                                       goto error;
-                               }
-                       } else {
-                               LTTNG_ASSERT(opt_userspace || opt_jul || opt_log4j || opt_python);
-                               if (opt_userspace) {
-                                       ev->loglevel = -1;
-                               } else if (opt_jul) {
-                                       ev->loglevel = LTTNG_LOGLEVEL_JUL_ALL;
-                               } else if (opt_log4j) {
-                                       ev->loglevel = LTTNG_LOGLEVEL_LOG4J_ALL;
-                               } else if (opt_python) {
-                                       ev->loglevel = LTTNG_LOGLEVEL_PYTHON_DEBUG;
-                               }
-                       }
-               }
-
-               if (opt_exclude) {
-                       ret = create_exclusion_list_and_validate("*",
-                               opt_exclude, &exclusions);
-                       if (ret) {
-                               ret = CMD_ERROR;
-                               goto error;
-                       }
-
-                       ev->exclusion = 1;
-                       warn_on_truncated_exclusion_names(&exclusions,
-                               &warn);
-               }
-               if (!opt_filter) {
-                       ret = lttng_enable_event_with_exclusions(handle,
-                                       ev, channel_name,
-                                       NULL,
-                                       lttng_dynamic_pointer_array_get_count(&exclusions),
-                                       (char **) exclusions.array.buffer.data);
-                       if (ret < 0) {
-                               switch (-ret) {
-                               case LTTNG_ERR_KERN_EVENT_EXIST:
-                                       WARN("Kernel events already enabled (channel %s, session %s)",
-                                                       print_channel_name(channel_name), session_name);
-                                       warn = 1;
-                                       break;
-                               case LTTNG_ERR_TRACE_ALREADY_STARTED:
-                               {
-                                       const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
-                                       ERR("Events: %s (channel %s, session %s)",
-                                                       msg,
-                                                       print_channel_name(channel_name),
-                                                       session_name);
-                                       error = 1;
-                                       break;
-                               }
-                               default:
-                                       ERR("Events: %s (channel %s, session %s)",
-                                                       lttng_strerror(ret),
-                                                       ret == -LTTNG_ERR_NEED_CHANNEL_NAME
-                                                               ? print_raw_channel_name(channel_name)
-                                                               : print_channel_name(channel_name),
-                                                       session_name);
-                                       error = 1;
-                                       break;
-                               }
-                               goto end;
-                       }
-
-                       switch (opt_event_type) {
-                       case LTTNG_EVENT_TRACEPOINT:
-                               if (opt_loglevel && dom.type != LTTNG_DOMAIN_KERNEL) {
-                                       char *exclusion_string = print_exclusions(&exclusions);
-
-                                       if (!exclusion_string) {
-                                               PERROR("Cannot allocate exclusion_string");
-                                               error = 1;
-                                               goto end;
-                                       }
-                                       MSG("All %s tracepoints%s are enabled in channel %s for loglevel %s",
-                                                       lttng_domain_type_str(dom.type),
-                                                       exclusion_string,
-                                                       print_channel_name(channel_name),
-                                                       opt_loglevel);
-                                       free(exclusion_string);
-                               } else {
-                                       char *exclusion_string = print_exclusions(&exclusions);
-
-                                       if (!exclusion_string) {
-                                               PERROR("Cannot allocate exclusion_string");
-                                               error = 1;
-                                               goto end;
-                                       }
-                                       MSG("All %s tracepoints%s are enabled in channel %s",
-                                                       lttng_domain_type_str(dom.type),
-                                                       exclusion_string,
-                                                       print_channel_name(channel_name));
-                                       free(exclusion_string);
-                               }
-                               break;
-                       case LTTNG_EVENT_SYSCALL:
-                               if (opt_kernel) {
-                                       MSG("All %s system calls are enabled in channel %s",
-                                                       lttng_domain_type_str(dom.type),
-                                                       print_channel_name(channel_name));
-                               }
-                               break;
-                       case LTTNG_EVENT_ALL:
-                               if (opt_loglevel && dom.type != LTTNG_DOMAIN_KERNEL) {
-                                       char *exclusion_string = print_exclusions(&exclusions);
-
-                                       if (!exclusion_string) {
-                                               PERROR("Cannot allocate exclusion_string");
-                                               error = 1;
-                                               goto end;
-                                       }
-                                       MSG("All %s events%s are enabled in channel %s for loglevel %s",
-                                                       lttng_domain_type_str(dom.type),
-                                                       exclusion_string,
-                                                       print_channel_name(channel_name),
-                                                       opt_loglevel);
-                                       free(exclusion_string);
-                               } else {
-                                       char *exclusion_string = print_exclusions(&exclusions);
-
-                                       if (!exclusion_string) {
-                                               PERROR("Cannot allocate exclusion_string");
-                                               error = 1;
-                                               goto end;
-                                       }
-                                       MSG("All %s events%s are enabled in channel %s",
-                                                       lttng_domain_type_str(dom.type),
-                                                       exclusion_string,
-                                                       print_channel_name(channel_name));
-                                       free(exclusion_string);
-                               }
-                               break;
-                       default:
-                               /*
-                                * We should not be here since lttng_enable_event should have
-                                * failed on the event type.
-                                */
-                               goto error;
-                       }
-               }
-
-               if (opt_filter) {
-                       command_ret = lttng_enable_event_with_exclusions(handle, ev, channel_name,
-                                       opt_filter,
-                                       lttng_dynamic_pointer_array_get_count(&exclusions),
-                                       (char **) exclusions.array.buffer.data);
-                       if (command_ret < 0) {
-                               switch (-command_ret) {
-                               case LTTNG_ERR_FILTER_EXIST:
-                                       WARN("Filter on all events is already enabled"
-                                                       " (channel %s, session %s)",
-                                               print_channel_name(channel_name), session_name);
-                                       warn = 1;
-                                       break;
-                               case LTTNG_ERR_TRACE_ALREADY_STARTED:
-                               {
-                                       const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
-                                       ERR("All events: %s (channel %s, session %s, filter \'%s\')",
-                                                       msg,
-                                                       print_channel_name(channel_name),
-                                                       session_name, opt_filter);
-                                       error = 1;
-                                       break;
-                               }
-                               default:
-                                       ERR("All events: %s (channel %s, session %s, filter \'%s\')",
-                                                       lttng_strerror(command_ret),
-                                                       command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
-                                                               ? print_raw_channel_name(channel_name)
-                                                               : print_channel_name(channel_name),
-                                                       session_name, opt_filter);
-                                       error = 1;
-                                       break;
-                               }
-                               error_holder = command_ret;
-                       } else {
-                               ev->filter = 1;
-                               MSG("Filter '%s' successfully set", opt_filter);
-                       }
-               }
-
-               if (lttng_opt_mi) {
-                       /* The wildcard * is used for kernel and ust domain to
-                        * represent ALL. We copy * in event name to force the wildcard use
-                        * for kernel domain
-                        *
-                        * Note: this is strictly for semantic and printing while in
-                        * machine interface mode.
-                        */
-                       strcpy(ev->name, "*");
-
-                       /* If we reach here the events are enabled */
-                       if (!error && !warn) {
-                               ev->enabled = 1;
-                       } else {
-                               ev->enabled = 0;
-                               success = 0;
-                       }
-                       ret = mi_lttng_event(writer, ev, 1, handle->domain.type);
-                       if (ret) {
-                               ret = CMD_ERROR;
-                               goto error;
-                       }
-
-                       /* print exclusion */
-                       ret = mi_print_exclusion(&exclusions);
-                       if (ret) {
-                               ret = CMD_ERROR;
-                               goto error;
-                       }
-
-                       /* Success ? */
-                       ret = mi_lttng_writer_write_element_bool(writer,
-                                       mi_lttng_element_command_success, success);
-                       if (ret) {
-                               ret = CMD_ERROR;
-                               goto error;
-                       }
-
-                       /* Close event element */
-                       ret = mi_lttng_writer_close_element(writer);
-                       if (ret) {
-                               ret = CMD_ERROR;
-                               goto error;
-                       }
-               }
-
-               goto end;
-       }
-
-       /* Strip event list */
-       event_name = strtok(opt_event_list, ",");
-       while (event_name != NULL) {
+       for (const auto& pattern : patterns) {
                /* Copy name and type of the event */
-               strncpy(ev->name, event_name, LTTNG_SYMBOL_NAME_LEN);
+               strncpy(ev->name, pattern.c_str(), LTTNG_SYMBOL_NAME_LEN);
                ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
                ev->type = (lttng_event_type) opt_event_type;
 
                /* Kernel tracer action */
                if (opt_kernel) {
-                       DBG("Enabling kernel event %s for channel %s",
-                                       event_name,
-                                       print_channel_name(channel_name));
+                       DBG_FMT("Enabling kernel event rule: pattern=`{}`, channel_name=`{}`",
+                               pattern,
+                               print_channel_name(channel_name));
 
                        switch (opt_event_type) {
-                       case LTTNG_EVENT_ALL:   /* Enable tracepoints and syscalls */
+                       case LTTNG_EVENT_ALL: /* Enable tracepoints and syscalls */
                                /* If event name differs from *, select tracepoint. */
-                               if (strcmp(ev->name, "*")) {
+                               if (strcmp(ev->name, "*") != 0) {
                                        ev->type = LTTNG_EVENT_TRACEPOINT;
                                }
                                break;
@@ -857,7 +557,7 @@ static int enable_events(char *session_name)
                                                break;
                                        case CMD_ERROR:
                                        default:
-                                               ERR("Unable to parse userspace probe options");
+                                               ERR("Unable to parse user space probe options");
                                                break;
                                        }
                                        goto error;
@@ -871,7 +571,7 @@ static int enable_events(char *session_name)
                                }
 
                                /* Ownership of the uprobe location was transferred to the event. */
-                               uprobe_loc = NULL;
+                               uprobe_loc = nullptr;
                                break;
                        case LTTNG_EVENT_FUNCTION:
                                ret = parse_probe_opts(ev, opt_function);
@@ -891,17 +591,19 @@ static int enable_events(char *session_name)
 
                        /* kernel loglevels not implemented */
                        ev->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
-               } else if (opt_userspace) {             /* User-space tracer action */
-                       DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
-                                       print_channel_name(channel_name), opt_loglevel ? : "<all>");
+               } else if (opt_userspace) { /* User-space tracer action */
+                       DBG_FMT("Enabling user space event rule: pattern=`{}`, channel_name=`{}`, log_level=`{}`",
+                               pattern.c_str(),
+                               print_channel_name(channel_name),
+                               opt_loglevel ?: "all");
 
                        switch (opt_event_type) {
-                       case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
+                       case LTTNG_EVENT_ALL: /* Default behavior is tracepoint */
                                /* Fall-through */
                        case LTTNG_EVENT_TRACEPOINT:
                                /* Copy name and type of the event */
                                ev->type = LTTNG_EVENT_TRACEPOINT;
-                               strncpy(ev->name, event_name, LTTNG_SYMBOL_NAME_LEN);
+                               strncpy(ev->name, pattern.c_str(), LTTNG_SYMBOL_NAME_LEN);
                                ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
                                break;
                        case LTTNG_EVENT_PROBE:
@@ -909,14 +611,16 @@ static int enable_events(char *session_name)
                        case LTTNG_EVENT_SYSCALL:
                        case LTTNG_EVENT_USERSPACE_PROBE:
                        default:
-                               ERR("Event type not available for user-space tracing");
+                               ERR("Instrumentation point type not supported for the %s domain",
+                                   lttng_domain_type_str(dom.type));
                                ret = CMD_UNSUPPORTED;
                                goto error;
                        }
 
                        if (opt_exclude) {
                                ev->exclusion = 1;
-                               if (opt_event_type != LTTNG_EVENT_ALL && opt_event_type != LTTNG_EVENT_TRACEPOINT) {
+                               if (opt_event_type != LTTNG_EVENT_ALL &&
+                                   opt_event_type != LTTNG_EVENT_TRACEPOINT) {
                                        ERR("Exclusion option can only be used with tracepoint events");
                                        ret = CMD_ERROR;
                                        goto error;
@@ -924,24 +628,23 @@ static int enable_events(char *session_name)
                                /* Free previously allocated items. */
                                lttng_dynamic_pointer_array_reset(&exclusions);
                                ret = create_exclusion_list_and_validate(
-                                       event_name, opt_exclude,
-                                       &exclusions);
+                                       pattern.c_str(), opt_exclude, &exclusions);
                                if (ret) {
                                        ret = CMD_ERROR;
                                        goto error;
                                }
 
-                               warn_on_truncated_exclusion_names(
-                                       &exclusions, &warn);
+                               warn_on_truncated_exclusion_names(&exclusions, &warn);
                        }
 
                        ev->loglevel_type = (lttng_loglevel_type) opt_loglevel_type;
                        if (opt_loglevel) {
                                enum lttng_loglevel loglevel;
-                               const int name_search_ret = loglevel_name_to_value(opt_loglevel, &loglevel);
+                               const int name_search_ret =
+                                       loglevel_name_to_value(opt_loglevel, &loglevel);
 
                                if (name_search_ret == -1) {
-                                       ERR("Unknown loglevel %s", opt_loglevel);
+                                       ERR("Unknown log level `%s`", opt_loglevel);
                                        ret = -LTTNG_ERR_INVALID;
                                        goto error;
                                }
@@ -952,8 +655,9 @@ static int enable_events(char *session_name)
                        }
                } else if (opt_jul || opt_log4j || opt_python) {
                        if (opt_event_type != LTTNG_EVENT_ALL &&
-                                       opt_event_type != LTTNG_EVENT_TRACEPOINT) {
-                               ERR("Event type not supported for domain.");
+                           opt_event_type != LTTNG_EVENT_TRACEPOINT) {
+                               ERR("Instrumentation point type not supported for the %s domain",
+                                   lttng_domain_type_str(dom.type));
                                ret = CMD_UNSUPPORTED;
                                goto error;
                        }
@@ -965,23 +669,26 @@ static int enable_events(char *session_name)
                                if (opt_jul) {
                                        enum lttng_loglevel_jul loglevel;
 
-                                       name_search_ret = loglevel_jul_name_to_value(opt_loglevel, &loglevel);
+                                       name_search_ret =
+                                               loglevel_jul_name_to_value(opt_loglevel, &loglevel);
                                        ev->loglevel = (int) loglevel;
                                } else if (opt_log4j) {
                                        enum lttng_loglevel_log4j loglevel;
 
-                                       name_search_ret = loglevel_log4j_name_to_value(opt_loglevel, &loglevel);
+                                       name_search_ret = loglevel_log4j_name_to_value(opt_loglevel,
+                                                                                      &loglevel);
                                        ev->loglevel = (int) loglevel;
                                } else {
                                        /* python domain. */
                                        enum lttng_loglevel_python loglevel;
 
-                                       name_search_ret = loglevel_python_name_to_value(opt_loglevel, &loglevel);
+                                       name_search_ret = loglevel_python_name_to_value(
+                                               opt_loglevel, &loglevel);
                                        ev->loglevel = (int) loglevel;
                                }
 
                                if (name_search_ret) {
-                                       ERR("Unknown loglevel %s", opt_loglevel);
+                                       ERR("Unknown log level `%s`", opt_loglevel);
                                        ret = -LTTNG_ERR_INVALID;
                                        goto error;
                                }
@@ -995,61 +702,75 @@ static int enable_events(char *session_name)
                                }
                        }
                        ev->type = LTTNG_EVENT_TRACEPOINT;
-                       strncpy(ev->name, event_name, LTTNG_SYMBOL_NAME_LEN);
+                       strncpy(ev->name, pattern.c_str(), LTTNG_SYMBOL_NAME_LEN);
                        ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
                } else {
                        abort();
                }
 
                if (!opt_filter) {
-                       char *exclusion_string;
-
-                       command_ret = lttng_enable_event_with_exclusions(handle,
-                                       ev, channel_name,
-                                       NULL,
-                                       lttng_dynamic_pointer_array_get_count(&exclusions),
-                                       (char **) exclusions.array.buffer.data);
-                       exclusion_string = print_exclusions(&exclusions);
+                       command_ret = lttng_enable_event_with_exclusions(
+                               handle,
+                               ev,
+                               channel_name,
+                               nullptr,
+                               lttng_dynamic_pointer_array_get_count(&exclusions),
+                               (char **) exclusions.array.buffer.data);
+
+                       auto exclusion_string =
+                               lttng::make_unique_wrapper<char, lttng::memory::free>(
+                                       print_exclusions(&exclusions));
                        if (!exclusion_string) {
                                PERROR("Cannot allocate exclusion_string");
                                error = 1;
                                goto end;
                        }
+
                        if (command_ret < 0) {
                                /* Turn ret to positive value to handle the positive error code */
                                switch (-command_ret) {
                                case LTTNG_ERR_KERN_EVENT_EXIST:
-                                       WARN("Kernel event %s%s already enabled (channel %s, session %s)",
-                                                       event_name,
-                                                       exclusion_string,
-                                                       print_channel_name(channel_name), session_name);
+                                       WARN("Kernel event rule %s%s and attached to channel `%s` is already enabled (session `%s`)",
+                                            opt_enable_all ? "matching all events" :
+                                                             (std::string("with pattern `") +
+                                                              pattern + std::string("`"))
+                                                                     .c_str(),
+                                            exclusion_string.get(),
+                                            print_channel_name(channel_name),
+                                            session_name.c_str());
                                        warn = 1;
                                        break;
                                case LTTNG_ERR_TRACE_ALREADY_STARTED:
                                {
-                                       const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
-                                       ERR("Event %s%s: %s (channel %s, session %s)", event_name,
-                                                       exclusion_string,
-                                                       msg,
-                                                       print_channel_name(channel_name),
-                                                       session_name);
+                                       ERR("Can't enable an event in a new domain for a session that has already been started once (session `%s`)",
+                                           session_name.c_str());
                                        error = 1;
                                        break;
                                }
                                case LTTNG_ERR_SDT_PROBE_SEMAPHORE:
-                                       ERR("SDT probes %s guarded by semaphores are not supported (channel %s, session %s)",
-                                                       event_name, print_channel_name(channel_name),
-                                                       session_name);
+                                       ERR("Failed to enable event rule with pattern `%s` and attached to channel `%s` as SDT probes guarded by semaphores are not supported (session `%s`)",
+                                           pattern.c_str(),
+                                           print_channel_name(channel_name),
+                                           session_name.c_str());
                                        error = 1;
                                        break;
                                default:
-                                       ERR("Event %s%s: %s (channel %s, session %s)", event_name,
-                                                       exclusion_string,
-                                                       lttng_strerror(command_ret),
-                                                       command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
-                                                               ? print_raw_channel_name(channel_name)
-                                                               : print_channel_name(channel_name),
-                                                       session_name);
+                                       ERR("Failed to enable event rule %s%s and attached to channel `%s`: %s (session `%s`)",
+                                           opt_enable_all ? "matching all events" :
+                                                            (std::string("with pattern `") +
+                                                             pattern + std::string("`"))
+                                                                    .c_str(),
+                                           exclusion_string.get(),
+                                           command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME ?
+                                                   print_raw_channel_name(channel_name) :
+                                                   print_channel_name(channel_name),
+                                           lttng_strerror(command_ret),
+                                           session_name.c_str());
+
+                                       if (opt_kernel) {
+                                               print_kernel_tracer_status_error();
+                                       }
+
                                        error = 1;
                                        break;
                                }
@@ -1058,12 +779,17 @@ static int enable_events(char *session_name)
                                switch (dom.type) {
                                case LTTNG_DOMAIN_KERNEL:
                                case LTTNG_DOMAIN_UST:
-                                       MSG("%s event %s%s created in channel %s",
-                                               lttng_domain_type_str(dom.type),
-                                               event_name,
-                                               exclusion_string,
-                                               print_channel_name(channel_name));
+                               {
+                                       MSG("Enabled %s event rule %s%s and attached to channel `%s`",
+                                           lttng_domain_type_str(dom.type),
+                                           opt_enable_all ? "matching all events" :
+                                                            (std::string("with pattern `") +
+                                                             pattern + std::string("`"))
+                                                                    .c_str(),
+                                           exclusion_string.get(),
+                                           print_channel_name(channel_name));
                                        break;
+                               }
                                case LTTNG_DOMAIN_JUL:
                                case LTTNG_DOMAIN_LOG4J:
                                case LTTNG_DOMAIN_PYTHON:
@@ -1071,74 +797,92 @@ static int enable_events(char *session_name)
                                         * Don't print the default channel
                                         * name for agent domains.
                                         */
-                                       MSG("%s event %s%s enabled",
-                                               lttng_domain_type_str(dom.type),
-                                               event_name,
-                                               exclusion_string);
+                                       MSG("Enabled %s event rule %s%s",
+                                           lttng_domain_type_str(dom.type),
+                                           opt_enable_all ? "matching all events" :
+                                                            (std::string("with pattern `") +
+                                                             pattern + std::string("`"))
+                                                                    .c_str(),
+                                           exclusion_string.get());
                                        break;
                                default:
                                        abort();
                                }
                        }
-                       free(exclusion_string);
-               }
-
-               if (opt_filter) {
-                       char *exclusion_string;
-
+               } else {
                        /* Filter present */
                        ev->filter = 1;
 
-                       command_ret = lttng_enable_event_with_exclusions(handle, ev, channel_name,
-                                       opt_filter,
-                                       lttng_dynamic_pointer_array_get_count(&exclusions),
-                                       (char **) exclusions.array.buffer.data);
-                       exclusion_string = print_exclusions(&exclusions);
+                       command_ret = lttng_enable_event_with_exclusions(
+                               handle,
+                               ev,
+                               channel_name,
+                               opt_filter,
+                               lttng_dynamic_pointer_array_get_count(&exclusions),
+                               (char **) exclusions.array.buffer.data);
+
+                       auto exclusion_string =
+                               lttng::make_unique_wrapper<char, lttng::memory::free>(
+                                       print_exclusions(&exclusions));
                        if (!exclusion_string) {
-                               PERROR("Cannot allocate exclusion_string");
+                               PERROR("Failed allocate exclusion string");
                                error = 1;
                                goto end;
                        }
                        if (command_ret < 0) {
                                switch (-command_ret) {
                                case LTTNG_ERR_FILTER_EXIST:
-                                       WARN("Filter on event %s%s is already enabled"
-                                                       " (channel %s, session %s)",
-                                               event_name,
-                                               exclusion_string,
-                                               print_channel_name(channel_name), session_name);
+                                       WARN("An event rule %s%s and filter expression `%s` is already attached to channel `%s`",
+                                            opt_enable_all ? "matching all events" :
+                                                             (std::string("with pattern `") +
+                                                              pattern + std::string("`"))
+                                                                     .c_str(),
+                                            exclusion_string.get(),
+                                            opt_filter,
+                                            print_channel_name(channel_name));
                                        warn = 1;
                                        break;
                                case LTTNG_ERR_TRACE_ALREADY_STARTED:
                                {
-                                       const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
-                                       ERR("Event %s%s: %s (channel %s, session %s, filter \'%s\')", ev->name,
-                                                       exclusion_string,
-                                                       msg,
-                                                       print_channel_name(channel_name),
-                                                       session_name, opt_filter);
+                                       ERR("Can't enable an event in a new domain for a session that has already been started once (session `%s`)",
+                                           session_name.c_str());
                                        error = 1;
                                        break;
                                }
                                default:
-                                       ERR("Event %s%s: %s (channel %s, session %s, filter \'%s\')", ev->name,
-                                                       exclusion_string,
-                                                       lttng_strerror(command_ret),
-                                                       command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
-                                                               ? print_raw_channel_name(channel_name)
-                                                               : print_channel_name(channel_name),
-                                                       session_name, opt_filter);
+                                       ERR("Failed to enable event rule %s%s, with filter expression `%s`, and attached to channel `%s`: %s (session `%s`)",
+                                           opt_enable_all ? "matching all events" :
+                                                            (std::string("with pattern `") +
+                                                             pattern + std::string("`"))
+                                                                    .c_str(),
+                                           exclusion_string.get(),
+                                           opt_filter,
+                                           command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME ?
+                                                   print_raw_channel_name(channel_name) :
+                                                   print_channel_name(channel_name),
+                                           lttng_strerror(command_ret),
+                                           session_name.c_str());
                                        error = 1;
+
+                                       if (opt_kernel) {
+                                               print_kernel_tracer_status_error();
+                                       }
+
                                        break;
                                }
-                               error_holder = command_ret;
 
+                               error_holder = command_ret;
                        } else {
-                               MSG("Event %s%s: Filter '%s' successfully set",
-                                               event_name, exclusion_string,
-                                               opt_filter);
+                               MSG("Enabled %s event rule %s%s and filter expression `%s`",
+                                   lttng_domain_type_str(dom.type),
+                                   opt_enable_all ? "matching all events" :
+                                                    (std::string("with pattern `") + pattern +
+                                                     std::string("`"))
+                                                            .c_str(),
+
+                                   exclusion_string.get(),
+                                   opt_filter);
                        }
-                       free(exclusion_string);
                }
 
                if (lttng_opt_mi) {
@@ -1149,7 +893,7 @@ static int enable_events(char *session_name)
                                ev->enabled = 1;
                        }
 
-                       ret = mi_lttng_event(writer, ev, 1, handle->domain.type);
+                       ret = mi_lttng_event(writer.get(), ev, 1, handle->domain.type);
                        if (ret) {
                                ret = CMD_ERROR;
                                goto error;
@@ -1163,23 +907,21 @@ static int enable_events(char *session_name)
                        }
 
                        /* Success ? */
-                       ret = mi_lttng_writer_write_element_bool(writer,
-                                       mi_lttng_element_command_success, success);
+                       ret = mi_lttng_writer_write_element_bool(
+                               writer.get(), mi_lttng_element_command_success, success);
                        if (ret) {
                                ret = CMD_ERROR;
                                goto end;
                        }
 
                        /* Close event element */
-                       ret = mi_lttng_writer_close_element(writer);
+                       ret = mi_lttng_writer_close_element(writer.get());
                        if (ret) {
                                ret = CMD_ERROR;
                                goto end;
                        }
                }
 
-               /* Next event */
-               event_name = strtok(NULL, ",");
                /* Reset warn, error and success */
                success = 1;
        }
@@ -1188,7 +930,7 @@ end:
        /* Close Mi */
        if (lttng_opt_mi) {
                /* Close events element */
-               ret = mi_lttng_writer_close_element(writer);
+               ret = mi_lttng_writer_close_element(writer.get());
                if (ret) {
                        ret = CMD_ERROR;
                        goto error;
@@ -1214,28 +956,83 @@ error:
        return ret;
 }
 
+void _poptContextFree_deleter_func(poptContext ctx)
+{
+       poptFreeContext(ctx);
+}
+
+} /* namespace */
+
+int validate_exclusion_list(const char *pattern,
+                           const struct lttng_dynamic_pointer_array *exclusions)
+{
+       int ret;
+
+       /* Event name pattern must be a valid globbing pattern to allow exclusions. */
+       if (!strutils_is_star_glob_pattern(pattern)) {
+               ERR("Event name pattern must contain wildcard characters to use exclusions");
+               goto error;
+       }
+
+       /*
+        * If the event name is a star-at-end only globbing pattern,
+        * then we can validate the individual exclusions. Otherwise
+        * all exclusions are passed to the session daemon.
+        */
+       if (strutils_is_star_at_the_end_only_glob_pattern(pattern)) {
+               size_t i, num_exclusions;
+
+               num_exclusions = lttng_dynamic_pointer_array_get_count(exclusions);
+
+               for (i = 0; i < num_exclusions; i++) {
+                       const char *exclusion =
+                               (const char *) lttng_dynamic_pointer_array_get_pointer(exclusions,
+                                                                                      i);
+
+                       if (!strutils_is_star_glob_pattern(exclusion) ||
+                           strutils_is_star_at_the_end_only_glob_pattern(exclusion)) {
+                               ret = check_exclusion_subsets(pattern, exclusion);
+                               if (ret) {
+                                       goto error;
+                               }
+                       }
+               }
+       }
+
+       ret = 0;
+       goto end;
+
+error:
+       ret = -1;
+
+end:
+       return ret;
+}
+
 /*
  * Add event to trace session
  */
 int cmd_enable_events(int argc, const char **argv)
 {
        int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
-       static poptContext pc;
-       char *session_name = NULL;
-       const char *leftover = NULL;
+       std::string session_name;
+       const char *arg_event_list = nullptr;
+       const char *leftover = nullptr;
        int event_type = -1;
+       event_rule_patterns patterns;
 
-       pc = poptGetContext(NULL, argc, argv, long_options, 0);
-       poptReadDefaultConfig(pc, 0);
+       auto pc = lttng::make_unique_wrapper<poptContext_s, _poptContextFree_deleter_func>(
+               poptGetContext(nullptr, argc, argv, long_options, 0));
+       poptReadDefaultConfig(pc.get(), 0);
 
        /* Default event type */
        opt_event_type = LTTNG_EVENT_ALL;
 
-       while ((opt = poptGetNextOpt(pc)) != -1) {
+       while ((opt = poptGetNextOpt(pc.get())) != -1) {
                switch (opt) {
                case OPT_HELP:
                        SHOW_HELP();
-                       goto end;
+                       return CMD_SUCCESS;
                case OPT_TRACEPOINT:
                        opt_event_type = LTTNG_EVENT_TRACEPOINT;
                        break;
@@ -1256,22 +1053,21 @@ int cmd_enable_events(int argc, const char **argv)
                        break;
                case OPT_LOGLEVEL:
                        opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
-                       opt_loglevel = poptGetOptArg(pc);
+                       opt_loglevel = poptGetOptArg(pc.get());
                        break;
                case OPT_LOGLEVEL_ONLY:
                        opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
-                       opt_loglevel = poptGetOptArg(pc);
+                       opt_loglevel = poptGetOptArg(pc.get());
                        break;
                case OPT_LIST_OPTIONS:
                        list_cmd_options(stdout, long_options);
-                       goto end;
+                       return CMD_SUCCESS;
                case OPT_FILTER:
                        break;
                case OPT_EXCLUDE:
                        break;
                default:
-                       ret = CMD_UNDEFINED;
-                       goto end;
+                       return CMD_UNDEFINED;
                }
 
                /* Validate event type. Multiple event type are not supported. */
@@ -1279,118 +1075,110 @@ int cmd_enable_events(int argc, const char **argv)
                        event_type = opt_event_type;
                } else {
                        if (event_type != opt_event_type) {
-                               ERR("Multiple event type not supported.");
-                               ret = CMD_ERROR;
-                               goto end;
+                               ERR("Only one event type may be enabled at once");
+                               return CMD_ERROR;
                        }
                }
        }
 
        ret = print_missing_or_multiple_domains(
-                       opt_kernel + opt_userspace + opt_jul + opt_log4j +
-                                       opt_python,
-                       true);
+               opt_kernel + opt_userspace + opt_jul + opt_log4j + opt_python, true);
        if (ret) {
-               ret = CMD_ERROR;
-               goto end;
+               return CMD_ERROR;
        }
 
        /* Mi check */
        if (lttng_opt_mi) {
-               writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
+               writer = mi_writer_uptr(mi_lttng_writer_create(fileno(stdout), lttng_opt_mi));
                if (!writer) {
-                       ret = -LTTNG_ERR_NOMEM;
-                       goto end;
+                       LTTNG_THROW_ERROR(lttng::format(
+                               "Failed to create MI writer: format_code={}", lttng_opt_mi));
                }
 
                /* Open command element */
-               ret = mi_lttng_writer_command_open(writer,
-                               mi_lttng_element_command_enable_event);
+               ret = mi_lttng_writer_command_open(writer.get(),
+                                                  mi_lttng_element_command_enable_event);
                if (ret) {
-                       ret = CMD_ERROR;
-                       goto end;
+                       LTTNG_THROW_ERROR(lttng::format(
+                               "Failed to open MI command element: command_name=`{}`",
+                               mi_lttng_element_command_enable_event));
                }
 
                /* Open output element */
-               ret = mi_lttng_writer_open_element(writer,
-                               mi_lttng_element_command_output);
+               ret = mi_lttng_writer_open_element(writer.get(), mi_lttng_element_command_output);
                if (ret) {
-                       ret = CMD_ERROR;
-                       goto end;
+                       LTTNG_THROW_ERROR(
+                               lttng::format("Failed to open MI element: element_name=`{}`",
+                                             mi_lttng_element_command_output));
                }
        }
 
-       opt_event_list = (char*) poptGetArg(pc);
-       if (opt_event_list == NULL && opt_enable_all == 0) {
-               ERR("Missing event name(s).\n");
-               ret = CMD_ERROR;
-               goto end;
-       }
-
-       leftover = poptGetArg(pc);
-       if (leftover) {
-               ERR("Unknown argument: %s", leftover);
-               ret = CMD_ERROR;
-               goto end;
-       }
-
-       if (!opt_session_name) {
-               session_name = get_session_name();
-               if (session_name == NULL) {
-                       command_ret = CMD_ERROR;
-                       success = 0;
-                       goto mi_closing;
+       /* Close the MI command context when leaving the function, no matter the result. */
+       const auto close_mi_on_exit = lttng::make_scope_exit([&success]() noexcept {
+               if (!lttng_opt_mi) {
+                       return;
                }
-       } else {
-               session_name = opt_session_name;
-       }
 
-       command_ret = enable_events(session_name);
-       if (command_ret) {
-               success = 0;
-               goto mi_closing;
-       }
+               /* Close output element. */
+               if (mi_lttng_writer_close_element(writer.get())) {
+                       ERR_FMT("Failed to close MI output element");
+                       return;
+               }
 
-mi_closing:
-       /* Mi closing */
-       if (lttng_opt_mi) {
-               /* Close  output element */
-               ret = mi_lttng_writer_close_element(writer);
-               if (ret) {
-                       ret = CMD_ERROR;
-                       goto end;
+               if (mi_lttng_writer_write_element_bool(
+                           writer.get(), mi_lttng_element_command_success, success)) {
+                       ERR_FMT("Failed to write MI element: element_name=`{}`, value={}",
+                               mi_lttng_element_command_success,
+                               success);
+                       return;
                }
 
-               ret = mi_lttng_writer_write_element_bool(writer,
-                               mi_lttng_element_command_success, success);
-               if (ret) {
-                       ret = CMD_ERROR;
-                       goto end;
+               /* Command element close. */
+               if (mi_lttng_writer_command_close(writer.get())) {
+                       ERR_FMT("Failed to close MI command element");
+                       return;
                }
+       });
 
-               /* Command element close */
-               ret = mi_lttng_writer_command_close(writer);
-               if (ret) {
-                       ret = CMD_ERROR;
-                       goto end;
+       arg_event_list = poptGetArg(pc.get());
+       if (arg_event_list == nullptr && opt_enable_all == 0) {
+               ERR("Missing event name pattern(s)");
+               return CMD_ERROR;
+       }
+
+       if (opt_enable_all) {
+               patterns.emplace_back("*");
+       } else {
+               std::stringstream event_list_arg_stream(arg_event_list);
+
+               for (std::string line; std::getline(event_list_arg_stream, line, ',');) {
+                       patterns.emplace_back(std::move(line));
                }
        }
 
-end:
-       /* Mi clean-up */
-       if (writer && mi_lttng_writer_destroy(writer)) {
-               /* Preserve original error code */
-               ret = ret ? ret : LTTNG_ERR_MI_IO_FAIL;
+       leftover = poptGetArg(pc.get());
+       if (leftover) {
+               ERR("Unknown argument: %s", leftover);
+               return CMD_ERROR;
        }
 
-       if (opt_session_name == NULL) {
-               free(session_name);
+       if (!opt_session_name) {
+               const auto rc_file_session_name =
+                       lttng::make_unique_wrapper<char, lttng::memory::free>(get_session_name());
+
+               if (!rc_file_session_name) {
+                       return CMD_ERROR;
+               }
+
+               session_name = rc_file_session_name.get();
+       } else {
+               session_name = opt_session_name;
        }
 
-       /* Overwrite ret if an error occurred in enable_events */
-       ret = command_ret ? command_ret : ret;
+       command_ret = enable_events(session_name, patterns);
+       if (command_ret) {
+               return CMD_ERROR;
+       }
 
-       poptFreeContext(pc);
-       return ret;
+       return CMD_SUCCESS;
 }
-
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