src/log.c - github/CESNET/libyang - Gitiles

 /**
  * @file log.c
  * @author Radek Krejci <rkrejci@cesnet.cz>
  * @brief Logger routines implementations
  *
  * Copyright (c) 2015 - 2018 CESNET, z.s.p.o.
  *
  * This source code is licensed under BSD 3-Clause License (the "License").
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     https://opensource.org/licenses/BSD-3-Clause
  */

 #define _GNU_SOURCE
 #define _POSIX_C_SOURCE 200809L /* strdup */

 #include "log.h"

 #include <assert.h>
 #include <inttypes.h>
 #include <pthread.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "common.h"
 #include "compat.h"
 #include "in_internal.h"
 #include "plugins_exts.h"
 #include "set.h"
 #include "tree_data.h"
 #include "tree_schema.h"

 volatile LY_LOG_LEVEL ly_ll = LY_LLWRN;
 volatile uint32_t ly_log_opts = LY_LOLOG | LY_LOSTORE_LAST;
 static ly_log_clb log_clb;
 static volatile ly_bool path_flag = 1;
 #ifndef NDEBUG
 volatile uint32_t ly_ldbg_groups = 0;
 #endif

 THREAD_LOCAL struct ly_log_location_s log_location = {0};

 /* how many bytes add when enlarging buffers */
 #define LY_BUF_STEP 128

 API LY_ERR
 ly_errcode(const struct ly_ctx *ctx)
 {
     struct ly_err_item *i;

     i = ly_err_last(ctx);
     if (i) {
         return i->no;
     }

     return LY_SUCCESS;
 }

 API LY_VECODE
 ly_vecode(const struct ly_ctx *ctx)
 {
     struct ly_err_item *i;

     i = ly_err_last(ctx);
     if (i) {
         return i->vecode;
     }

     return LYVE_SUCCESS;
 }

 API const char *
 ly_errmsg(const struct ly_ctx *ctx)
 {
     struct ly_err_item *i;

     LY_CHECK_ARG_RET(NULL, ctx, NULL);

     i = ly_err_last(ctx);
     if (i) {
         return i->msg;
     }

     return NULL;
 }

 API const char *
 ly_errpath(const struct ly_ctx *ctx)
 {
     struct ly_err_item *i;

     LY_CHECK_ARG_RET(NULL, ctx, NULL);

     i = ly_err_last(ctx);
     if (i) {
         return i->path;
     }

     return NULL;
 }

 API const char *
 ly_errapptag(const struct ly_ctx *ctx)
 {
     struct ly_err_item *i;

     LY_CHECK_ARG_RET(NULL, ctx, NULL);

     i = ly_err_last(ctx);
     if (i) {
         return i->apptag;
     }

     return NULL;
 }

 API LY_ERR
 ly_err_new(struct ly_err_item **err, LY_ERR ecode, LY_VECODE vecode, char *path, char *apptag, const char *err_msg, ...)
 {
     char *msg = NULL;
     struct ly_err_item *e;

     if (!err || (ecode == LY_SUCCESS)) {
         /* nothing to do */
         return ecode;
     }

     e = malloc(sizeof *e);
     LY_CHECK_ERR_RET(!e, LOGMEM(NULL), LY_EMEM);
     e->prev = (*err) ? (*err)->prev : e;
     e->next = NULL;
     if (*err) {
         (*err)->prev->next = e;
     }

     /* fill in the information */
     e->level = LY_LLERR;
     e->no = ecode;
     e->vecode = vecode;
     e->path = path;
     e->apptag = apptag;

     if (err_msg) {
         va_list print_args;

         va_start(print_args, err_msg);

         if (vasprintf(&msg, err_msg, print_args) == -1) {
             /* we don't have anything more to do, just set err_msg to NULL to avoid undefined content,
              * still keep the information about the original error instead of LY_EMEM or other printf's error */
             msg = NULL;
         }

         va_end(print_args);
     }
     e->msg = msg;

     if (!(*err)) {
         *err = e;
     }

     return e->no;
 }

 API struct ly_err_item *
 ly_err_first(const struct ly_ctx *ctx)
 {
     LY_CHECK_ARG_RET(NULL, ctx, NULL);

     return pthread_getspecific(ctx->errlist_key);
 }

 API struct ly_err_item *
 ly_err_last(const struct ly_ctx *ctx)
 {
     const struct ly_err_item *e;

     LY_CHECK_ARG_RET(NULL, ctx, NULL);

     e = pthread_getspecific(ctx->errlist_key);
     return e ? e->prev : NULL;
 }

 API void
 ly_err_free(void *ptr)
 {
     struct ly_err_item *i, *next;

     /* clean the error list */
     for (i = (struct ly_err_item *)ptr; i; i = next) {
         next = i->next;
         free(i->msg);
         free(i->path);
         free(i->apptag);
         free(i);
     }
 }

 API void
 ly_err_clean(struct ly_ctx *ctx, struct ly_err_item *eitem)
 {
     struct ly_err_item *i, *first;

     first = ly_err_first(ctx);
     if (first == eitem) {
         eitem = NULL;
     }
     if (eitem) {
         /* disconnect the error */
         for (i = first; i && (i->next != eitem); i = i->next) {}
         assert(i);
         i->next = NULL;
         first->prev = i;
         /* free this err and newer */
         ly_err_free(eitem);
     } else {
         /* free all err */
         ly_err_free(first);
         pthread_setspecific(ctx->errlist_key, NULL);
     }
 }

 API LY_LOG_LEVEL
 ly_log_level(LY_LOG_LEVEL level)
 {
     LY_LOG_LEVEL prev = ly_ll;

     ly_ll = level;
     return prev;
 }

 API uint32_t
 ly_log_options(uint32_t opts)
 {
     uint32_t prev = ly_log_opts;

     ly_log_opts = opts;
     return prev;
 }

 API uint32_t
 ly_log_dbg_groups(uint32_t dbg_groups)
 {
 #ifndef NDEBUG
     uint32_t prev = ly_ldbg_groups;

     ly_ldbg_groups = dbg_groups;
     return prev;
 #else
     (void)dbg_groups;
     return 0;
 #endif
 }

 API void
 ly_set_log_clb(ly_log_clb clb, ly_bool path)
 {
     log_clb = clb;
     path_flag = path;
 }

 API ly_log_clb
 ly_get_log_clb(void)
 {
     return log_clb;
 }

 void
 ly_log_location(const struct lysc_node *scnode, const struct lyd_node *dnode,
         const char *path, const struct ly_in *in, uint64_t line, ly_bool reset)
 {
     if (scnode) {
         ly_set_add(&log_location.scnodes, (void *)scnode, 1, NULL);
     } else if (reset) {
         ly_set_erase(&log_location.scnodes, NULL);
     }

     if (dnode) {
         ly_set_add(&log_location.dnodes, (void *)dnode, 1, NULL);
     } else if (reset) {
         ly_set_erase(&log_location.dnodes, NULL);
     }

     if (path) {
         char *s = strdup(path);
         LY_CHECK_ERR_RET(!s, LOGMEM(NULL), );
         ly_set_add(&log_location.paths, s, 1, NULL);
     } else if (reset) {
         ly_set_erase(&log_location.paths, free);
     }

     if (in) {
         ly_set_add(&log_location.inputs, (void *)in, 1, NULL);
     } else if (reset) {
         ly_set_erase(&log_location.inputs, NULL);
     }

     if (line) {
         log_location.line = line;
     }
 }

 void
 ly_log_location_revert(uint32_t scnode_steps, uint32_t dnode_steps,
         uint32_t path_steps, uint32_t in_steps)
 {
     for (uint32_t i = scnode_steps; i && log_location.scnodes.count; i--) {
         log_location.scnodes.count--;
     }

     for (uint32_t i = dnode_steps; i && log_location.dnodes.count; i--) {
         log_location.dnodes.count--;
     }

     for (uint32_t i = path_steps; i && log_location.paths.count; i--) {
         ly_set_rm_index(&log_location.paths, log_location.paths.count - 1, free);
     }

     for (uint32_t i = in_steps; i && log_location.inputs.count; i--) {
         log_location.inputs.count--;
     }

     /* deallocate the empty sets */
     if (scnode_steps && !log_location.scnodes.count) {
         ly_set_erase(&log_location.scnodes, NULL);
     }
     if (dnode_steps && !log_location.dnodes.count) {
         ly_set_erase(&log_location.dnodes, NULL);
     }
     if (path_steps && !log_location.paths.count) {
         ly_set_erase(&log_location.paths, free);
     }
     if (in_steps && !log_location.inputs.count) {
         ly_set_erase(&log_location.inputs, NULL);
     }
 }

 static LY_ERR
 log_store(const struct ly_ctx *ctx, LY_LOG_LEVEL level, LY_ERR no, LY_VECODE vecode, char *msg, char *path, char *apptag)
 {
     struct ly_err_item *eitem, *last;

     assert(ctx && (level < LY_LLVRB));

     eitem = pthread_getspecific(ctx->errlist_key);
     if (!eitem) {
         /* if we are only to fill in path, there must have been an error stored */
         assert(msg);
         eitem = malloc(sizeof *eitem);
         LY_CHECK_GOTO(!eitem, mem_fail);
         eitem->prev = eitem;
         eitem->next = NULL;

         pthread_setspecific(ctx->errlist_key, eitem);
     } else if (!msg) {
         /* only filling the path */
         assert(path);

         /* find last error */
         eitem = eitem->prev;
         do {
             if (eitem->level == LY_LLERR) {
                 /* fill the path */
                 free(eitem->path);
                 eitem->path = path;
                 return LY_SUCCESS;
             }
             eitem = eitem->prev;
         } while (eitem->prev->next);
         /* last error was not found */
         assert(0);
     } else if ((ly_log_opts & LY_LOSTORE_LAST) == LY_LOSTORE_LAST) {
         /* overwrite last message */
         free(eitem->msg);
         free(eitem->path);
         free(eitem->apptag);
     } else {
         /* store new message */
         last = eitem->prev;
         eitem->prev = malloc(sizeof *eitem);
         LY_CHECK_GOTO(!eitem->prev, mem_fail);
         eitem = eitem->prev;
         eitem->prev = last;
         eitem->next = NULL;
         last->next = eitem;
     }

     /* fill in the information */
     eitem->level = level;
     eitem->no = no;
     eitem->vecode = vecode;
     eitem->msg = msg;
     eitem->path = path;
     eitem->apptag = apptag;
     return LY_SUCCESS;

 mem_fail:
     LOGMEM(NULL);
     free(msg);
     free(path);
     free(apptag);
     return LY_EMEM;
 }

 static void
 log_vprintf(const struct ly_ctx *ctx, LY_LOG_LEVEL level, LY_ERR no, LY_VECODE vecode, char *path,
         const char *format, va_list args)
 {
     char *msg = NULL;
     ly_bool free_strs;

     if (level > ly_ll) {
         /* do not print or store the message */
         free(path);
         return;
     }

     /* store the error/warning (if we need to store errors internally, it does not matter what are the user log options) */
     if ((level < LY_LLVRB) && ctx && (ly_log_opts & LY_LOSTORE)) {
         assert(format);
         if (vasprintf(&msg, format, args) == -1) {
             LOGMEM(ctx);
             free(path);
             return;
         }
         if (((no & ~LY_EPLUGIN) == LY_EVALID) && (vecode == LYVE_SUCCESS)) {
             /* assume we are inheriting the error, so inherit vecode as well */
             vecode = ly_vecode(ctx);
         }
         if (log_store(ctx, level, no, vecode, msg, path, NULL)) {
             return;
         }
         free_strs = 0;
     } else {
         if (vasprintf(&msg, format, args) == -1) {
             LOGMEM(ctx);
             free(path);
             return;
         }
         free_strs = 1;
     }

     /* if we are only storing errors internally, never print the message (yet) */
     if (ly_log_opts & LY_LOLOG) {
         if (log_clb) {
             log_clb(level, msg, path);
         } else {
             fprintf(stderr, "libyang[%d]: %s%s", level, msg, path ? " " : "\n");
             if (path) {
                 fprintf(stderr, "(path: %s)\n", path);
             }
         }
     }

     if (free_strs) {
         free(path);
         free(msg);
     }
 }

 #ifndef NDEBUG

 void
 ly_log_dbg(uint32_t group, const char *format, ...)
 {
     char *dbg_format;
     const char *str_group;
     va_list ap;

     if (!(ly_ldbg_groups & group)) {
         return;
     }

     switch (group) {
     case LY_LDGDICT:
         str_group = "DICT";
         break;
     case LY_LDGXPATH:
         str_group = "XPATH";
         break;
     default:
         LOGINT(NULL);
         return;
     }

     if (asprintf(&dbg_format, "%s: %s", str_group, format) == -1) {
         LOGMEM(NULL);
         return;
     }

     va_start(ap, format);
     log_vprintf(NULL, LY_LLDBG, 0, 0, NULL, dbg_format, ap);
     va_end(ap);
 }

 #endif

 void
 ly_log(const struct ly_ctx *ctx, LY_LOG_LEVEL level, LY_ERR no, const char *format, ...)
 {
     va_list ap;

     va_start(ap, format);
     log_vprintf(ctx, level, no, 0, NULL, format, ap);
     va_end(ap);
 }

 static LY_ERR
 ly_vlog_build_path(const struct ly_ctx *ctx, char **path)
 {
     int rc;
     char *str = NULL, *prev = NULL;

     *path = NULL;

     if (log_location.paths.count && ((const char *)(log_location.paths.objs[log_location.paths.count - 1]))[0]) {
         /* simply get what is in the provided path string */
         *path = strdup((const char *)log_location.paths.objs[log_location.paths.count - 1]);
         LY_CHECK_ERR_RET(!(*path), LOGMEM(ctx), LY_EMEM);
     } else {
         /* generate location string */
         if (log_location.scnodes.count) {
             str = lysc_path(log_location.scnodes.objs[log_location.scnodes.count - 1], LYSC_PATH_LOG, NULL, 0);
             LY_CHECK_ERR_RET(!str, LOGMEM(ctx), LY_EMEM);

             rc = asprintf(path, "Schema location %s", str);
             free(str);
             LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
         }
         if (log_location.dnodes.count) {
             prev = *path;
             str = lyd_path(log_location.dnodes.objs[log_location.dnodes.count - 1], LYD_PATH_STD, NULL, 0);
             LY_CHECK_ERR_RET(!str, LOGMEM(ctx), LY_EMEM);

             rc = asprintf(path, "%s%sata location %s", prev ? prev : "", prev ? ", d" : "D", str);
             free(str);
             free(prev);
             LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
         }
         if (log_location.line) {
             prev = *path;
             rc = asprintf(path, "%s%sine number %" PRIu64, prev ? prev : "", prev ? ", l" : "L", log_location.line);
             free(prev);
             LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);

             log_location.line = 0;
         } else if (log_location.inputs.count) {
             prev = *path;
             rc = asprintf(path, "%s%sine number %" PRIu64, prev ? prev : "", prev ? ", l" : "L",
                     ((struct ly_in *)log_location.inputs.objs[log_location.inputs.count - 1])->line);
             free(prev);
             LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
         }

         if (*path) {
             prev = *path;
             rc = asprintf(path, "%s.", prev);
             free(prev);
             LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
         }
     }

     return LY_SUCCESS;
 }

 void
 ly_vlog(const struct ly_ctx *ctx, LY_VECODE code, const char *format, ...)
 {
     va_list ap;
     char *path = NULL;

     if (path_flag && ctx) {
         ly_vlog_build_path(ctx, &path);
     }

     va_start(ap, format);
     log_vprintf(ctx, LY_LLERR, LY_EVALID, code, path, format, ap);
     /* path is spent and should not be freed! */
     va_end(ap);
 }

 API void
 lyplg_ext_log(const struct lysc_ext_instance *ext, LY_LOG_LEVEL level, LY_ERR err_no, const char *path, const char *format, ...)
 {
     va_list ap;
     char *plugin_msg;
     int ret;

     if (ly_ll < level) {
         return;
     }
     ret = asprintf(&plugin_msg, "Extension plugin \"%s\": %s", ext->def->plugin->id, format);
     if (ret == -1) {
         LOGMEM(ext->module->ctx);
         return;
     }

     va_start(ap, format);
     log_vprintf(ext->module->ctx, level, (level == LY_LLERR ? LY_EPLUGIN : 0) | err_no, LYVE_OTHER, path ? strdup(path) : NULL, plugin_msg, ap);
     va_end(ap);

     free(plugin_msg);
 }

 /**
  * @brief Exact same functionality as ::ly_err_print() but has variable arguments so va_start() can
  * be used and an empty va_list created.
  */
 static void
 _ly_err_print(const struct ly_ctx *ctx, struct ly_err_item *eitem, ...)
 {
     va_list ap;
     char *path_dup = NULL;

     LY_CHECK_ARG_RET(ctx, eitem, );

     if (eitem->path) {
         /* duplicate path because it will be freed */
         path_dup = strdup(eitem->path);
         LY_CHECK_ERR_RET(!path_dup, LOGMEM(ctx), );
     }

     va_start(ap, eitem);
     log_vprintf(ctx, eitem->level, eitem->no, eitem->vecode, eitem->path, eitem->msg, ap);
     va_end(ap);

     if (path_dup) {
         eitem->path = path_dup;
     }
 }

 API void
 ly_err_print(const struct ly_ctx *ctx, struct ly_err_item *eitem)
 {
     _ly_err_print(ctx, eitem);
 }
	/**
	* @file log.c
	* @author Radek Krejci <rkrejci@cesnet.cz>
	* @brief Logger routines implementations
	*
	* Copyright (c) 2015 - 2018 CESNET, z.s.p.o.
	*
	* This source code is licensed under BSD 3-Clause License (the "License").
	* You may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* https://opensource.org/licenses/BSD-3-Clause
	*/

	#define _GNU_SOURCE
	#define _POSIX_C_SOURCE 200809L /* strdup */

	#include "log.h"

	#include <assert.h>
	#include <inttypes.h>
	#include <pthread.h>
	#include <stdarg.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include "common.h"
	#include "compat.h"
	#include "in_internal.h"
	#include "plugins_exts.h"
	#include "set.h"
	#include "tree_data.h"
	#include "tree_schema.h"

	volatile LY_LOG_LEVEL ly_ll = LY_LLWRN;
	volatile uint32_t ly_log_opts = LY_LOLOG \| LY_LOSTORE_LAST;
	static ly_log_clb log_clb;
	static volatile ly_bool path_flag = 1;
	#ifndef NDEBUG
	volatile uint32_t ly_ldbg_groups = 0;
	#endif

	THREAD_LOCAL struct ly_log_location_s log_location = {0};

	/* how many bytes add when enlarging buffers */
	#define LY_BUF_STEP 128

	API LY_ERR
	ly_errcode(const struct ly_ctx *ctx)
	{
	struct ly_err_item *i;

	i = ly_err_last(ctx);
	if (i) {
	return i->no;
	}

	return LY_SUCCESS;
	}

	API LY_VECODE
	ly_vecode(const struct ly_ctx *ctx)
	{
	struct ly_err_item *i;

	i = ly_err_last(ctx);
	if (i) {
	return i->vecode;
	}

	return LYVE_SUCCESS;
	}

	API const char *
	ly_errmsg(const struct ly_ctx *ctx)
	{
	struct ly_err_item *i;

	LY_CHECK_ARG_RET(NULL, ctx, NULL);

	i = ly_err_last(ctx);
	if (i) {
	return i->msg;
	}

	return NULL;
	}

	API const char *
	ly_errpath(const struct ly_ctx *ctx)
	{
	struct ly_err_item *i;

	LY_CHECK_ARG_RET(NULL, ctx, NULL);

	i = ly_err_last(ctx);
	if (i) {
	return i->path;
	}

	return NULL;
	}

	API const char *
	ly_errapptag(const struct ly_ctx *ctx)
	{
	struct ly_err_item *i;

	LY_CHECK_ARG_RET(NULL, ctx, NULL);

	i = ly_err_last(ctx);
	if (i) {
	return i->apptag;
	}

	return NULL;
	}

	API LY_ERR
	ly_err_new(struct ly_err_item *err, LY_ERR ecode, LY_VECODE vecode, char path, char apptag, const char err_msg, ...)
	{
	char *msg = NULL;
	struct ly_err_item *e;

	if (!err \|\| (ecode == LY_SUCCESS)) {
	/* nothing to do */
	return ecode;
	}

	e = malloc(sizeof *e);
	LY_CHECK_ERR_RET(!e, LOGMEM(NULL), LY_EMEM);
	e->prev = (err) ? (err)->prev : e;
	e->next = NULL;
	if (*err) {
	(*err)->prev->next = e;
	}

	/* fill in the information */
	e->level = LY_LLERR;
	e->no = ecode;
	e->vecode = vecode;
	e->path = path;
	e->apptag = apptag;

	if (err_msg) {
	va_list print_args;

	va_start(print_args, err_msg);

	if (vasprintf(&msg, err_msg, print_args) == -1) {
	/* we don't have anything more to do, just set err_msg to NULL to avoid undefined content,
	* still keep the information about the original error instead of LY_EMEM or other printf's error */
	msg = NULL;
	}

	va_end(print_args);
	}
	e->msg = msg;

	if (!(*err)) {
	*err = e;
	}

	return e->no;
	}

	API struct ly_err_item *
	ly_err_first(const struct ly_ctx *ctx)
	{
	LY_CHECK_ARG_RET(NULL, ctx, NULL);

	return pthread_getspecific(ctx->errlist_key);
	}

	API struct ly_err_item *
	ly_err_last(const struct ly_ctx *ctx)
	{
	const struct ly_err_item *e;

	LY_CHECK_ARG_RET(NULL, ctx, NULL);

	e = pthread_getspecific(ctx->errlist_key);
	return e ? e->prev : NULL;
	}

	API void
	ly_err_free(void *ptr)
	{
	struct ly_err_item i, next;

	/* clean the error list */
	for (i = (struct ly_err_item *)ptr; i; i = next) {
	next = i->next;
	free(i->msg);
	free(i->path);
	free(i->apptag);
	free(i);
	}
	}

	API void
	ly_err_clean(struct ly_ctx ctx, struct ly_err_item eitem)
	{
	struct ly_err_item i, first;

	first = ly_err_first(ctx);
	if (first == eitem) {
	eitem = NULL;
	}
	if (eitem) {
	/* disconnect the error */
	for (i = first; i && (i->next != eitem); i = i->next) {}
	assert(i);
	i->next = NULL;
	first->prev = i;
	/* free this err and newer */
	ly_err_free(eitem);
	} else {
	/* free all err */
	ly_err_free(first);
	pthread_setspecific(ctx->errlist_key, NULL);
	}
	}

	API LY_LOG_LEVEL
	ly_log_level(LY_LOG_LEVEL level)
	{
	LY_LOG_LEVEL prev = ly_ll;

	ly_ll = level;
	return prev;
	}

	API uint32_t
	ly_log_options(uint32_t opts)
	{
	uint32_t prev = ly_log_opts;

	ly_log_opts = opts;
	return prev;
	}

	API uint32_t
	ly_log_dbg_groups(uint32_t dbg_groups)
	{
	#ifndef NDEBUG
	uint32_t prev = ly_ldbg_groups;

	ly_ldbg_groups = dbg_groups;
	return prev;
	#else
	(void)dbg_groups;
	return 0;
	#endif
	}

	API void
	ly_set_log_clb(ly_log_clb clb, ly_bool path)
	{
	log_clb = clb;
	path_flag = path;
	}

	API ly_log_clb
	ly_get_log_clb(void)
	{
	return log_clb;
	}

	void
	ly_log_location(const struct lysc_node scnode, const struct lyd_node dnode,
	const char path, const struct ly_in in, uint64_t line, ly_bool reset)
	{
	if (scnode) {
	ly_set_add(&log_location.scnodes, (void *)scnode, 1, NULL);
	} else if (reset) {
	ly_set_erase(&log_location.scnodes, NULL);
	}

	if (dnode) {
	ly_set_add(&log_location.dnodes, (void *)dnode, 1, NULL);
	} else if (reset) {
	ly_set_erase(&log_location.dnodes, NULL);
	}

	if (path) {
	char *s = strdup(path);
	LY_CHECK_ERR_RET(!s, LOGMEM(NULL), );
	ly_set_add(&log_location.paths, s, 1, NULL);
	} else if (reset) {
	ly_set_erase(&log_location.paths, free);
	}

	if (in) {
	ly_set_add(&log_location.inputs, (void *)in, 1, NULL);
	} else if (reset) {
	ly_set_erase(&log_location.inputs, NULL);
	}

	if (line) {
	log_location.line = line;
	}
	}

	void
	ly_log_location_revert(uint32_t scnode_steps, uint32_t dnode_steps,
	uint32_t path_steps, uint32_t in_steps)
	{
	for (uint32_t i = scnode_steps; i && log_location.scnodes.count; i--) {
	log_location.scnodes.count--;
	}

	for (uint32_t i = dnode_steps; i && log_location.dnodes.count; i--) {
	log_location.dnodes.count--;
	}

	for (uint32_t i = path_steps; i && log_location.paths.count; i--) {
	ly_set_rm_index(&log_location.paths, log_location.paths.count - 1, free);
	}

	for (uint32_t i = in_steps; i && log_location.inputs.count; i--) {
	log_location.inputs.count--;
	}

	/* deallocate the empty sets */
	if (scnode_steps && !log_location.scnodes.count) {
	ly_set_erase(&log_location.scnodes, NULL);
	}
	if (dnode_steps && !log_location.dnodes.count) {
	ly_set_erase(&log_location.dnodes, NULL);
	}
	if (path_steps && !log_location.paths.count) {
	ly_set_erase(&log_location.paths, free);
	}
	if (in_steps && !log_location.inputs.count) {
	ly_set_erase(&log_location.inputs, NULL);
	}
	}

	static LY_ERR
	log_store(const struct ly_ctx ctx, LY_LOG_LEVEL level, LY_ERR no, LY_VECODE vecode, char msg, char path, char apptag)
	{
	struct ly_err_item eitem, last;

	assert(ctx && (level < LY_LLVRB));

	eitem = pthread_getspecific(ctx->errlist_key);
	if (!eitem) {
	/* if we are only to fill in path, there must have been an error stored */
	assert(msg);
	eitem = malloc(sizeof *eitem);
	LY_CHECK_GOTO(!eitem, mem_fail);
	eitem->prev = eitem;
	eitem->next = NULL;

	pthread_setspecific(ctx->errlist_key, eitem);
	} else if (!msg) {
	/* only filling the path */
	assert(path);

	/* find last error */
	eitem = eitem->prev;
	do {
	if (eitem->level == LY_LLERR) {
	/* fill the path */
	free(eitem->path);
	eitem->path = path;
	return LY_SUCCESS;
	}
	eitem = eitem->prev;
	} while (eitem->prev->next);
	/* last error was not found */
	assert(0);
	} else if ((ly_log_opts & LY_LOSTORE_LAST) == LY_LOSTORE_LAST) {
	/* overwrite last message */
	free(eitem->msg);
	free(eitem->path);
	free(eitem->apptag);
	} else {
	/* store new message */
	last = eitem->prev;
	eitem->prev = malloc(sizeof *eitem);
	LY_CHECK_GOTO(!eitem->prev, mem_fail);
	eitem = eitem->prev;
	eitem->prev = last;
	eitem->next = NULL;
	last->next = eitem;
	}

	/* fill in the information */
	eitem->level = level;
	eitem->no = no;
	eitem->vecode = vecode;
	eitem->msg = msg;
	eitem->path = path;
	eitem->apptag = apptag;
	return LY_SUCCESS;

	mem_fail:
	LOGMEM(NULL);
	free(msg);
	free(path);
	free(apptag);
	return LY_EMEM;
	}

	static void
	log_vprintf(const struct ly_ctx ctx, LY_LOG_LEVEL level, LY_ERR no, LY_VECODE vecode, char path,
	const char *format, va_list args)
	{
	char *msg = NULL;
	ly_bool free_strs;

	if (level > ly_ll) {
	/* do not print or store the message */
	free(path);
	return;
	}

	/* store the error/warning (if we need to store errors internally, it does not matter what are the user log options) */
	if ((level < LY_LLVRB) && ctx && (ly_log_opts & LY_LOSTORE)) {
	assert(format);
	if (vasprintf(&msg, format, args) == -1) {
	LOGMEM(ctx);
	free(path);
	return;
	}
	if (((no & ~LY_EPLUGIN) == LY_EVALID) && (vecode == LYVE_SUCCESS)) {
	/* assume we are inheriting the error, so inherit vecode as well */
	vecode = ly_vecode(ctx);
	}
	if (log_store(ctx, level, no, vecode, msg, path, NULL)) {
	return;
	}
	free_strs = 0;
	} else {
	if (vasprintf(&msg, format, args) == -1) {
	LOGMEM(ctx);
	free(path);
	return;
	}
	free_strs = 1;
	}

	/* if we are only storing errors internally, never print the message (yet) */
	if (ly_log_opts & LY_LOLOG) {
	if (log_clb) {
	log_clb(level, msg, path);
	} else {
	fprintf(stderr, "libyang[%d]: %s%s", level, msg, path ? " " : "\n");
	if (path) {
	fprintf(stderr, "(path: %s)\n", path);
	}
	}
	}

	if (free_strs) {
	free(path);
	free(msg);
	}
	}

	#ifndef NDEBUG

	void
	ly_log_dbg(uint32_t group, const char *format, ...)
	{
	char *dbg_format;
	const char *str_group;
	va_list ap;

	if (!(ly_ldbg_groups & group)) {
	return;
	}

	switch (group) {
	case LY_LDGDICT:
	str_group = "DICT";
	break;
	case LY_LDGXPATH:
	str_group = "XPATH";
	break;
	default:
	LOGINT(NULL);
	return;
	}

	if (asprintf(&dbg_format, "%s: %s", str_group, format) == -1) {
	LOGMEM(NULL);
	return;
	}

	va_start(ap, format);
	log_vprintf(NULL, LY_LLDBG, 0, 0, NULL, dbg_format, ap);
	va_end(ap);
	}

	#endif

	void
	ly_log(const struct ly_ctx ctx, LY_LOG_LEVEL level, LY_ERR no, const char format, ...)
	{
	va_list ap;

	va_start(ap, format);
	log_vprintf(ctx, level, no, 0, NULL, format, ap);
	va_end(ap);
	}

	static LY_ERR
	ly_vlog_build_path(const struct ly_ctx ctx, char *path)
	{
	int rc;
	char str = NULL, prev = NULL;

	*path = NULL;

	if (log_location.paths.count && ((const char *)(log_location.paths.objs[log_location.paths.count - 1]))[0]) {
	/* simply get what is in the provided path string */
	path = strdup((const char )log_location.paths.objs[log_location.paths.count - 1]);
	LY_CHECK_ERR_RET(!(*path), LOGMEM(ctx), LY_EMEM);
	} else {
	/* generate location string */
	if (log_location.scnodes.count) {
	str = lysc_path(log_location.scnodes.objs[log_location.scnodes.count - 1], LYSC_PATH_LOG, NULL, 0);
	LY_CHECK_ERR_RET(!str, LOGMEM(ctx), LY_EMEM);

	rc = asprintf(path, "Schema location %s", str);
	free(str);
	LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
	}
	if (log_location.dnodes.count) {
	prev = *path;
	str = lyd_path(log_location.dnodes.objs[log_location.dnodes.count - 1], LYD_PATH_STD, NULL, 0);
	LY_CHECK_ERR_RET(!str, LOGMEM(ctx), LY_EMEM);

	rc = asprintf(path, "%s%sata location %s", prev ? prev : "", prev ? ", d" : "D", str);
	free(str);
	free(prev);
	LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
	}
	if (log_location.line) {
	prev = *path;
	rc = asprintf(path, "%s%sine number %" PRIu64, prev ? prev : "", prev ? ", l" : "L", log_location.line);
	free(prev);
	LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);

	log_location.line = 0;
	} else if (log_location.inputs.count) {
	prev = *path;
	rc = asprintf(path, "%s%sine number %" PRIu64, prev ? prev : "", prev ? ", l" : "L",
	((struct ly_in *)log_location.inputs.objs[log_location.inputs.count - 1])->line);
	free(prev);
	LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
	}

	if (*path) {
	prev = *path;
	rc = asprintf(path, "%s.", prev);
	free(prev);
	LY_CHECK_ERR_RET(rc == -1, LOGMEM(ctx), LY_EMEM);
	}
	}

	return LY_SUCCESS;
	}

	void
	ly_vlog(const struct ly_ctx ctx, LY_VECODE code, const char format, ...)
	{
	va_list ap;
	char *path = NULL;

	if (path_flag && ctx) {
	ly_vlog_build_path(ctx, &path);
	}

	va_start(ap, format);
	log_vprintf(ctx, LY_LLERR, LY_EVALID, code, path, format, ap);
	/* path is spent and should not be freed! */
	va_end(ap);
	}

	API void
	lyplg_ext_log(const struct lysc_ext_instance ext, LY_LOG_LEVEL level, LY_ERR err_no, const char path, const char *format, ...)
	{
	va_list ap;
	char *plugin_msg;
	int ret;

	if (ly_ll < level) {
	return;
	}
	ret = asprintf(&plugin_msg, "Extension plugin \"%s\": %s", ext->def->plugin->id, format);
	if (ret == -1) {
	LOGMEM(ext->module->ctx);
	return;
	}

	va_start(ap, format);
	log_vprintf(ext->module->ctx, level, (level == LY_LLERR ? LY_EPLUGIN : 0) \| err_no, LYVE_OTHER, path ? strdup(path) : NULL, plugin_msg, ap);
	va_end(ap);

	free(plugin_msg);
	}

	/**
	* @brief Exact same functionality as ::ly_err_print() but has variable arguments so va_start() can
	* be used and an empty va_list created.
	*/
	static void
	_ly_err_print(const struct ly_ctx ctx, struct ly_err_item eitem, ...)
	{
	va_list ap;
	char *path_dup = NULL;

	LY_CHECK_ARG_RET(ctx, eitem, );

	if (eitem->path) {
	/* duplicate path because it will be freed */
	path_dup = strdup(eitem->path);
	LY_CHECK_ERR_RET(!path_dup, LOGMEM(ctx), );
	}

	va_start(ap, eitem);
	log_vprintf(ctx, eitem->level, eitem->no, eitem->vecode, eitem->path, eitem->msg, ap);
	va_end(ap);

	if (path_dup) {
	eitem->path = path_dup;
	}
	}

	API void
	ly_err_print(const struct ly_ctx ctx, struct ly_err_item eitem)
	{
	_ly_err_print(ctx, eitem);
	}