Adding upstream version 2.1.30.upstream/2.1.30upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1798 insertions, 0 deletions

diff --git a/src/schema_compile.c b/src/schema_compile.c
new file mode 100644
index 0000000..ed768ba
--- /dev/null
+++ b/src/schema_compile.c
@@ -0,0 +1,1798 @@
+/**
+ * @file schema_compile.c
+ * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @author Michal Vasko <mvasko@cesnet.cz>
+ * @brief Schema compilation.
+ *
+ * Copyright (c) 2015 - 2022 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
+
+#include "schema_compile.h"
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "compat.h"
+#include "context.h"
+#include "dict.h"
+#include "in.h"
+#include "log.h"
+#include "parser_schema.h"
+#include "path.h"
+#include "plugins.h"
+#include "plugins_exts.h"
+#include "plugins_internal.h"
+#include "plugins_types.h"
+#include "schema_compile_amend.h"
+#include "schema_compile_node.h"
+#include "schema_features.h"
+#include "set.h"
+#include "tree.h"
+#include "tree_data.h"
+#include "tree_schema.h"
+#include "tree_schema_free.h"
+#include "tree_schema_internal.h"
+#include "xpath.h"
+
+void
+lysc_update_path(struct lysc_ctx *ctx, const struct lys_module *parent_module, const char *name)
+{
+    int len;
+    uint8_t nextlevel = 0; /* 0 - no starttag, 1 - '/' starttag, 2 - '=' starttag + '}' endtag */
+
+    if (!name) {
+        /* removing last path segment */
+        if (ctx->path[ctx->path_len - 1] == '}') {
+            for ( ; ctx->path[ctx->path_len] != '=' && ctx->path[ctx->path_len] != '{'; --ctx->path_len) {}
+            if (ctx->path[ctx->path_len] == '=') {
+                ctx->path[ctx->path_len++] = '}';
+            } else {
+                /* not a top-level special tag, remove also preceiding '/' */
+                goto remove_nodelevel;
+            }
+        } else {
+remove_nodelevel:
+            for ( ; ctx->path[ctx->path_len] != '/'; --ctx->path_len) {}
+            if (ctx->path_len == 0) {
+                /* top-level (last segment) */
+                ctx->path_len = 1;
+            }
+        }
+        /* set new terminating NULL-byte */
+        ctx->path[ctx->path_len] = '\0';
+    } else {
+        if (ctx->path_len > 1) {
+            if (!parent_module && (ctx->path[ctx->path_len - 1] == '}') && (ctx->path[ctx->path_len - 2] != '\'')) {
+                /* extension of the special tag */
+                nextlevel = 2;
+                --ctx->path_len;
+            } else {
+                /* there is already some path, so add next level */
+                nextlevel = 1;
+            }
+        } /* else the path is just initiated with '/', so do not add additional slash in case of top-level nodes */
+
+        if (nextlevel != 2) {
+            if ((parent_module && (parent_module == ctx->cur_mod)) || (!parent_module && (ctx->path_len > 1) && (name[0] == '{'))) {
+                /* module not changed, print the name unprefixed */
+                len = snprintf(&ctx->path[ctx->path_len], LYSC_CTX_BUFSIZE - ctx->path_len, "%s%s", nextlevel ? "/" : "", name);
+            } else {
+                len = snprintf(&ctx->path[ctx->path_len], LYSC_CTX_BUFSIZE - ctx->path_len, "%s%s:%s", nextlevel ? "/" : "", ctx->cur_mod->name, name);
+            }
+        } else {
+            len = snprintf(&ctx->path[ctx->path_len], LYSC_CTX_BUFSIZE - ctx->path_len, "='%s'}", name);
+        }
+        if (len >= LYSC_CTX_BUFSIZE - (int)ctx->path_len) {
+            /* output truncated */
+            ctx->path_len = LYSC_CTX_BUFSIZE - 1;
+        } else {
+            ctx->path_len += len;
+        }
+    }
+
+    LOG_LOCBACK(0, 0, 1, 0);
+    LOG_LOCSET(NULL, NULL, ctx->path, NULL);
+}
+
+/**
+ * @brief Fill in the prepared compiled extensions definition structure according to the parsed extension definition.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] extp Parsed extension instance.
+ * @param[out] ext Compiled extension definition.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_extension(struct lysc_ctx *ctx, struct lysp_ext_instance *extp, struct lysc_ext **ext)
+{
+    LY_ERR ret = LY_SUCCESS;
+    struct lysp_ext *ep = extp->def;
+
+    if (!ep->compiled) {
+        lysc_update_path(ctx, NULL, "{extension}");
+        lysc_update_path(ctx, NULL, ep->name);
+
+        /* compile the extension definition */
+        *ext = ep->compiled = calloc(1, sizeof **ext);
+        (*ext)->refcount = 1;
+        DUP_STRING_GOTO(ctx->ctx, ep->name, (*ext)->name, ret, cleanup);
+        DUP_STRING_GOTO(ctx->ctx, ep->argname, (*ext)->argname, ret, cleanup);
+        LY_CHECK_GOTO(ret = lysp_ext_find_definition(ctx->ctx, extp, (const struct lys_module **)&(*ext)->module, NULL),
+                cleanup);
+
+        /* compile nested extensions */
+        COMPILE_EXTS_GOTO(ctx, ep->exts, (*ext)->exts, *ext, ret, cleanup);
+
+        lysc_update_path(ctx, NULL, NULL);
+        lysc_update_path(ctx, NULL, NULL);
+
+        /* find extension definition plugin */
+        (*ext)->plugin = extp->record ? (struct lyplg_ext *)&extp->record->plugin : NULL;
+    }
+
+    *ext = ep->compiled;
+
+cleanup:
+    if (ret) {
+        lysc_update_path(ctx, NULL, NULL);
+        lysc_update_path(ctx, NULL, NULL);
+    }
+    return ret;
+}
+
+LY_ERR
+lys_compile_ext(struct lysc_ctx *ctx, struct lysp_ext_instance *extp, struct lysc_ext_instance *ext, void *parent)
+{
+    LY_ERR ret = LY_SUCCESS;
+
+    DUP_STRING_GOTO(ctx->ctx, extp->argument, ext->argument, ret, cleanup);
+    ext->module = ctx->cur_mod;
+    ext->parent = parent;
+    ext->parent_stmt = extp->parent_stmt;
+    ext->parent_stmt_index = extp->parent_stmt_index;
+
+    lysc_update_path(ctx, (ext->parent_stmt & LY_STMT_NODE_MASK) ? ((struct lysc_node *)ext->parent)->module : NULL,
+            "{extension}");
+    lysc_update_path(ctx, NULL, extp->name);
+
+    /* compile extension if not already */
+    LY_CHECK_GOTO(ret = lys_compile_extension(ctx, extp, &ext->def), cleanup);
+
+    /* compile */
+    if (ext->def->plugin && ext->def->plugin->compile) {
+        if (ext->argument) {
+            lysc_update_path(ctx, ext->module, ext->argument);
+        }
+        ret = ext->def->plugin->compile(ctx, extp, ext);
+        if (ret == LY_ENOT) {
+            lysc_ext_instance_free(&ctx->free_ctx, ext);
+        }
+        if (ext->argument) {
+            lysc_update_path(ctx, NULL, NULL);
+        }
+        LY_CHECK_GOTO(ret, cleanup);
+    }
+
+cleanup:
+    lysc_update_path(ctx, NULL, NULL);
+    lysc_update_path(ctx, NULL, NULL);
+    return ret;
+}
+
+static void
+lysc_unres_must_free(struct lysc_unres_must *m)
+{
+    LY_ARRAY_FREE(m->local_mods);
+    free(m);
+}
+
+static void
+lysc_unres_dflt_free(const struct ly_ctx *ctx, struct lysc_unres_dflt *r)
+{
+    assert(!r->dflt || !r->dflts);
+    if (r->dflt) {
+        lysp_qname_free((struct ly_ctx *)ctx, r->dflt);
+        free(r->dflt);
+    } else {
+        FREE_ARRAY((struct ly_ctx *)ctx, r->dflts, lysp_qname_free);
+    }
+    free(r);
+}
+
+LY_ERR
+lys_identity_precompile(struct lysc_ctx *ctx_sc, struct ly_ctx *ctx, struct lysp_module *parsed_mod,
+        const struct lysp_ident *identities_p, struct lysc_ident **identities)
+{
+    LY_ARRAY_COUNT_TYPE u;
+    struct lysc_ctx cctx;
+    struct lysc_ident *ident;
+    LY_ERR ret = LY_SUCCESS;
+
+    assert(ctx_sc || ctx);
+
+    if (!ctx_sc) {
+        if (parsed_mod) {
+            LYSC_CTX_INIT_PMOD(cctx, parsed_mod, NULL);
+        } else {
+            LYSC_CTX_INIT_CTX(cctx, ctx);
+        }
+        ctx_sc = &cctx;
+    }
+
+    if (!identities_p) {
+        return LY_SUCCESS;
+    }
+
+    lysc_update_path(ctx_sc, NULL, "{identity}");
+    LY_ARRAY_FOR(identities_p, u) {
+        lysc_update_path(ctx_sc, NULL, identities_p[u].name);
+
+        /* add new compiled identity */
+        LY_ARRAY_NEW_GOTO(ctx_sc->ctx, *identities, ident, ret, done);
+
+        DUP_STRING_GOTO(ctx_sc->ctx, identities_p[u].name, ident->name, ret, done);
+        DUP_STRING_GOTO(ctx_sc->ctx, identities_p[u].dsc, ident->dsc, ret, done);
+        DUP_STRING_GOTO(ctx_sc->ctx, identities_p[u].ref, ident->ref, ret, done);
+        ident->module = ctx_sc->cur_mod;
+        /* backlinks (derived) can be added no sooner than when all the identities in the current module are present */
+        COMPILE_EXTS_GOTO(ctx_sc, identities_p[u].exts, ident->exts, ident, ret, done);
+        ident->flags = identities_p[u].flags;
+
+        lysc_update_path(ctx_sc, NULL, NULL);
+    }
+    lysc_update_path(ctx_sc, NULL, NULL);
+
+done:
+    if (ret) {
+        lysc_update_path(ctx_sc, NULL, NULL);
+        lysc_update_path(ctx_sc, NULL, NULL);
+    }
+    return ret;
+}
+
+/**
+ * @brief Check circular dependency of identities - identity MUST NOT reference itself (via their base statement).
+ *
+ * The function works in the same way as lys_compile_feature_circular_check() with different structures and error messages.
+ *
+ * @param[in] ctx Compile context for logging.
+ * @param[in] ident The base identity (its derived list is being extended by the identity being currently processed).
+ * @param[in] derived The list of derived identities of the identity being currently processed (not the one provided as @p ident)
+ * @return LY_SUCCESS if everything is ok.
+ * @return LY_EVALID if the identity is derived from itself.
+ */
+static LY_ERR
+lys_compile_identity_circular_check(struct lysc_ctx *ctx, struct lysc_ident *ident, struct lysc_ident **derived)
+{
+    LY_ERR ret = LY_SUCCESS;
+    LY_ARRAY_COUNT_TYPE u, v;
+    struct ly_set recursion = {0};
+    struct lysc_ident *drv;
+
+    if (!derived) {
+        return LY_SUCCESS;
+    }
+
+    for (u = 0; u < LY_ARRAY_COUNT(derived); ++u) {
+        if (ident == derived[u]) {
+            LOGVAL(ctx->ctx, LYVE_REFERENCE,
+                    "Identity \"%s\" is indirectly derived from itself.", ident->name);
+            ret = LY_EVALID;
+            goto cleanup;
+        }
+        ret = ly_set_add(&recursion, derived[u], 0, NULL);
+        LY_CHECK_GOTO(ret, cleanup);
+    }
+
+    for (v = 0; v < recursion.count; ++v) {
+        drv = recursion.objs[v];
+        for (u = 0; u < LY_ARRAY_COUNT(drv->derived); ++u) {
+            if (ident == drv->derived[u]) {
+                LOGVAL(ctx->ctx, LYVE_REFERENCE,
+                        "Identity \"%s\" is indirectly derived from itself.", ident->name);
+                ret = LY_EVALID;
+                goto cleanup;
+            }
+            ret = ly_set_add(&recursion, drv->derived[u], 0, NULL);
+            LY_CHECK_GOTO(ret, cleanup);
+        }
+    }
+
+cleanup:
+    ly_set_erase(&recursion, NULL);
+    return ret;
+}
+
+LY_ERR
+lys_compile_identity_bases(struct lysc_ctx *ctx, const struct lysp_module *base_pmod, const char **bases_p,
+        struct lysc_ident *ident, struct lysc_ident ***bases)
+{
+    LY_ARRAY_COUNT_TYPE u, v;
+    const char *s, *name;
+    const struct lys_module *mod;
+    struct lysc_ident **idref;
+
+    assert(ident || bases);
+
+    if ((LY_ARRAY_COUNT(bases_p) > 1) && (ctx->pmod->version < LYS_VERSION_1_1)) {
+        LOGVAL(ctx->ctx, LYVE_SYNTAX_YANG,
+                "Multiple bases in %s are allowed only in YANG 1.1 modules.", ident ? "identity" : "identityref type");
+        return LY_EVALID;
+    }
+
+    LY_ARRAY_FOR(bases_p, u) {
+        s = strchr(bases_p[u], ':');
+        if (s) {
+            /* prefixed identity */
+            name = &s[1];
+            mod = ly_resolve_prefix(ctx->ctx, bases_p[u], s - bases_p[u], LY_VALUE_SCHEMA, (void *)base_pmod);
+        } else {
+            name = bases_p[u];
+            mod = base_pmod->mod;
+        }
+        if (!mod) {
+            if (ident) {
+                LOGVAL(ctx->ctx, LYVE_SYNTAX_YANG,
+                        "Invalid prefix used for base (%s) of identity \"%s\".", bases_p[u], ident->name);
+            } else {
+                LOGVAL(ctx->ctx, LYVE_SYNTAX_YANG,
+                        "Invalid prefix used for base (%s) of identityref.", bases_p[u]);
+            }
+            return LY_EVALID;
+        }
+
+        idref = NULL;
+        LY_ARRAY_FOR(mod->identities, v) {
+            if (!strcmp(name, mod->identities[v].name)) {
+                if (ident) {
+                    if (ident == &mod->identities[v]) {
+                        LOGVAL(ctx->ctx, LYVE_REFERENCE,
+                                "Identity \"%s\" is derived from itself.", ident->name);
+                        return LY_EVALID;
+                    }
+                    LY_CHECK_RET(lys_compile_identity_circular_check(ctx, &mod->identities[v], ident->derived));
+                    /* we have match! store the backlink */
+                    LY_ARRAY_NEW_RET(ctx->ctx, mod->identities[v].derived, idref, LY_EMEM);
+                    *idref = ident;
+                } else {
+                    /* we have match! store the found identity */
+                    LY_ARRAY_NEW_RET(ctx->ctx, *bases, idref, LY_EMEM);
+                    *idref = &mod->identities[v];
+                }
+                break;
+            }
+        }
+        if (!idref) {
+            if (ident) {
+                LOGVAL(ctx->ctx, LYVE_SYNTAX_YANG,
+                        "Unable to find base (%s) of identity \"%s\".", bases_p[u], ident->name);
+            } else {
+                LOGVAL(ctx->ctx, LYVE_SYNTAX_YANG,
+                        "Unable to find base (%s) of identityref.", bases_p[u]);
+            }
+            return LY_EVALID;
+        }
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief For the given array of identities, set the backlinks from all their base identities.
+ *
+ * @param[in] ctx Compile context, not only for logging but also to get the current module to resolve prefixes.
+ * @param[in] idents_p Array of identities definitions from the parsed schema structure.
+ * @param[in,out] idents Array of referencing identities to which the backlinks are supposed to be set.
+ * @return LY_ERR value - LY_SUCCESS or LY_EVALID.
+ */
+static LY_ERR
+lys_compile_identities_derived(struct lysc_ctx *ctx, struct lysp_ident *idents_p, struct lysc_ident **idents)
+{
+    LY_ARRAY_COUNT_TYPE u, v;
+
+    lysc_update_path(ctx, NULL, "{identity}");
+
+    for (u = 0; u < LY_ARRAY_COUNT(*idents); ++u) {
+        /* find matching parsed identity */
+        for (v = 0; v < LY_ARRAY_COUNT(idents_p); ++v) {
+            if (idents_p[v].name == (*idents)[u].name) {
+                break;
+            }
+        }
+
+        if ((v == LY_ARRAY_COUNT(idents_p)) || !idents_p[v].bases) {
+            /* identity not found (it may be from a submodule) or identity without bases */
+            continue;
+        }
+
+        lysc_update_path(ctx, NULL, (*idents)[u].name);
+        LY_CHECK_RET(lys_compile_identity_bases(ctx, ctx->pmod, idents_p[v].bases, &(*idents)[u], NULL));
+        lysc_update_path(ctx, NULL, NULL);
+    }
+
+    lysc_update_path(ctx, NULL, NULL);
+    return LY_SUCCESS;
+}
+
+LY_ERR
+lys_compile_expr_implement(const struct ly_ctx *ctx, const struct lyxp_expr *expr, LY_VALUE_FORMAT format,
+        void *prefix_data, ly_bool implement, struct lys_glob_unres *unres, const struct lys_module **mod_p)
+{
+    uint32_t i;
+    const char *ptr, *start, **imp_f, *all_f[] = {"*", NULL};
+    const struct lys_module *mod;
+
+    assert(implement || mod_p);
+
+    for (i = 0; i < expr->used; ++i) {
+        if ((expr->tokens[i] != LYXP_TOKEN_NAMETEST) && (expr->tokens[i] != LYXP_TOKEN_LITERAL)) {
+            /* token cannot have a prefix */
+            continue;
+        }
+
+        start = expr->expr + expr->tok_pos[i];
+        if (!(ptr = ly_strnchr(start, ':', expr->tok_len[i]))) {
+            /* token without a prefix */
+            continue;
+        }
+
+        if (!(mod = ly_resolve_prefix(ctx, start, ptr - start, format, prefix_data))) {
+            /* unknown prefix, do not care right now */
+            continue;
+        }
+
+        /* unimplemented module found */
+        if (!mod->implemented && !implement) {
+            /* should not be implemented now */
+            *mod_p = mod;
+            break;
+        }
+
+        if (!mod->implemented) {
+            /* implement if not implemented */
+            imp_f = (ctx->flags & LY_CTX_ENABLE_IMP_FEATURES) ? all_f : NULL;
+            LY_CHECK_RET(lys_implement((struct lys_module *)mod, imp_f, unres));
+        }
+        if (!mod->compiled) {
+            /* compile if not implemented before or only marked for compilation */
+            LY_CHECK_RET(lys_compile((struct lys_module *)mod, &unres->ds_unres));
+        }
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Check and optionally implement modules referenced by a when expression.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] when When to check.
+ * @param[in,out] unres Global unres structure.
+ * @return LY_ERECOMPILE if the whole dep set needs to be recompiled for these whens to evaluate.
+ * @return LY_ENOT if full check of this when should be skipped.
+ * @return LY_ERR value on error.
+ */
+static LY_ERR
+lys_compile_unres_when_implement(struct lysc_ctx *ctx, const struct lysc_when *when, struct lys_glob_unres *unres)
+{
+    LY_ERR rc = LY_SUCCESS;
+    const struct lys_module *mod = NULL;
+
+    /* check whether all the referenced modules are implemented */
+    rc = lys_compile_expr_implement(ctx->ctx, when->cond, LY_VALUE_SCHEMA_RESOLVED, when->prefixes,
+            ctx->ctx->flags & LY_CTX_REF_IMPLEMENTED, unres, &mod);
+    if (rc) {
+        goto cleanup;
+    } else if (mod) {
+        LOGWRN(ctx->ctx, "When condition \"%s\" check skipped because referenced module \"%s\" is not implemented.",
+                when->cond->expr, mod->name);
+        rc = LY_ENOT;
+        goto cleanup;
+    }
+
+cleanup:
+    return rc;
+}
+
+/**
+ * @brief Check when for cyclic dependencies.
+ *
+ * @param[in] set Set with all the referenced nodes.
+ * @param[in] node Node whose "when" referenced nodes are in @p set.
+ * @return LY_ERR value
+ */
+static LY_ERR
+lys_compile_unres_when_cyclic(struct lyxp_set *set, const struct lysc_node *node)
+{
+    struct lyxp_set tmp_set;
+    struct lyxp_set_scnode *xp_scnode;
+    uint32_t i, j;
+    LY_ARRAY_COUNT_TYPE u;
+    LY_ERR ret = LY_SUCCESS;
+
+    memset(&tmp_set, 0, sizeof tmp_set);
+
+    /* prepare in_ctx of the set */
+    for (i = 0; i < set->used; ++i) {
+        xp_scnode = &set->val.scnodes[i];
+
+        if (xp_scnode->in_ctx != LYXP_SET_SCNODE_START_USED) {
+            /* check node when, skip the context node (it was just checked) */
+            xp_scnode->in_ctx = LYXP_SET_SCNODE_ATOM_CTX;
+        }
+    }
+
+    for (i = 0; i < set->used; ++i) {
+        xp_scnode = &set->val.scnodes[i];
+        if (xp_scnode->in_ctx != LYXP_SET_SCNODE_ATOM_CTX) {
+            /* already checked */
+            continue;
+        }
+
+        if ((xp_scnode->type != LYXP_NODE_ELEM) || !lysc_node_when(xp_scnode->scnode)) {
+            /* no when to check */
+            xp_scnode->in_ctx = LYXP_SET_SCNODE_ATOM_NODE;
+            continue;
+        }
+
+        node = xp_scnode->scnode;
+        do {
+            struct lysc_when **when_list, *when;
+
+            LOG_LOCSET(node, NULL, NULL, NULL);
+            when_list = lysc_node_when(node);
+            LY_ARRAY_FOR(when_list, u) {
+                when = when_list[u];
+                ret = lyxp_atomize(set->ctx, when->cond, node->module, LY_VALUE_SCHEMA_RESOLVED, when->prefixes,
+                        when->context, when->context, &tmp_set, LYXP_SCNODE_SCHEMA);
+                if (ret != LY_SUCCESS) {
+                    LOGVAL(set->ctx, LYVE_SEMANTICS, "Invalid when condition \"%s\".", when->cond->expr);
+                    LOG_LOCBACK(1, 0, 0, 0);
+                    goto cleanup;
+                }
+
+                for (j = 0; j < tmp_set.used; ++j) {
+                    /* skip roots'n'stuff */
+                    if (tmp_set.val.scnodes[j].type == LYXP_NODE_ELEM) {
+                        /* try to find this node in our set */
+                        uint32_t idx;
+
+                        if (lyxp_set_scnode_contains(set, tmp_set.val.scnodes[j].scnode, LYXP_NODE_ELEM, -1, &idx) &&
+                                (set->val.scnodes[idx].in_ctx == LYXP_SET_SCNODE_START_USED)) {
+                            LOGVAL(set->ctx, LYVE_SEMANTICS, "When condition cyclic dependency on the node \"%s\".",
+                                    tmp_set.val.scnodes[j].scnode->name);
+                            ret = LY_EVALID;
+                            LOG_LOCBACK(1, 0, 0, 0);
+                            goto cleanup;
+                        }
+
+                        /* needs to be checked, if in both sets, will be ignored */
+                        tmp_set.val.scnodes[j].in_ctx = LYXP_SET_SCNODE_ATOM_CTX;
+                    } else {
+                        /* no when, nothing to check */
+                        tmp_set.val.scnodes[j].in_ctx = LYXP_SET_SCNODE_ATOM_NODE;
+                    }
+                }
+
+                /* merge this set into the global when set */
+                lyxp_set_scnode_merge(set, &tmp_set);
+            }
+
+            /* check when of non-data parents as well */
+            node = node->parent;
+
+            LOG_LOCBACK(1, 0, 0, 0);
+        } while (node && (node->nodetype & (LYS_CASE | LYS_CHOICE)));
+
+        /* this node when was checked (xp_scnode could have been reallocd) */
+        set->val.scnodes[i].in_ctx = LYXP_SET_SCNODE_ATOM_NODE;
+    }
+
+cleanup:
+    lyxp_set_free_content(&tmp_set);
+    return ret;
+}
+
+LY_ERR
+lysc_check_status(struct lysc_ctx *ctx, uint16_t flags1, void *mod1, const char *name1, uint16_t flags2, void *mod2,
+        const char *name2)
+{
+    uint16_t flg1, flg2;
+
+    flg1 = (flags1 & LYS_STATUS_MASK) ? (flags1 & LYS_STATUS_MASK) : LYS_STATUS_CURR;
+    flg2 = (flags2 & LYS_STATUS_MASK) ? (flags2 & LYS_STATUS_MASK) : LYS_STATUS_CURR;
+
+    if ((flg1 < flg2) && (mod1 == mod2)) {
+        if (ctx) {
+            LOGVAL(ctx->ctx, LYVE_REFERENCE, "A %s definition \"%s\" is not allowed to reference %s definition \"%s\".",
+                    flg1 == LYS_STATUS_CURR ? "current" : "deprecated", name1,
+                    flg2 == LYS_STATUS_OBSLT ? "obsolete" : "deprecated", name2);
+        }
+        return LY_EVALID;
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Check when expressions of a node on a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] when When to check.
+ * @param[in] node Node with @p when.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_when(struct lysc_ctx *ctx, const struct lysc_when *when, const struct lysc_node *node)
+{
+    struct lyxp_set tmp_set = {0};
+    uint32_t i, opts;
+    LY_ERR ret = LY_SUCCESS;
+
+    opts = LYXP_SCNODE_SCHEMA | ((node->flags & LYS_IS_OUTPUT) ? LYXP_SCNODE_OUTPUT : 0);
+
+    /* check "when" */
+    ret = lyxp_atomize(ctx->ctx, when->cond, node->module, LY_VALUE_SCHEMA_RESOLVED, when->prefixes, when->context,
+            when->context, &tmp_set, opts);
+    if (ret) {
+        LOGVAL(ctx->ctx, LYVE_SEMANTICS, "Invalid when condition \"%s\".", when->cond->expr);
+        goto cleanup;
+    }
+
+    ctx->path[0] = '\0';
+    lysc_path(node, LYSC_PATH_LOG, ctx->path, LYSC_CTX_BUFSIZE);
+    for (i = 0; i < tmp_set.used; ++i) {
+        /* skip roots'n'stuff */
+        if ((tmp_set.val.scnodes[i].type == LYXP_NODE_ELEM) &&
+                (tmp_set.val.scnodes[i].in_ctx != LYXP_SET_SCNODE_START_USED)) {
+            struct lysc_node *schema = tmp_set.val.scnodes[i].scnode;
+
+            /* XPath expression cannot reference "lower" status than the node that has the definition */
+            if (lysc_check_status(NULL, when->flags, node->module, node->name, schema->flags, schema->module,
+                    schema->name)) {
+                LOGWRN(ctx->ctx, "When condition \"%s\" may be referencing %s node \"%s\".", when->cond->expr,
+                        (schema->flags == LYS_STATUS_OBSLT) ? "obsolete" : "deprecated", schema->name);
+            }
+
+            /* check dummy node children/value accessing */
+            if (lysc_data_parent(schema) == node) {
+                LOGVAL(ctx->ctx, LYVE_SEMANTICS, "When condition is accessing its own conditional node children.");
+                ret = LY_EVALID;
+                goto cleanup;
+            } else if ((schema == node) && (tmp_set.val.scnodes[i].in_ctx == LYXP_SET_SCNODE_ATOM_VAL)) {
+                LOGVAL(ctx->ctx, LYVE_SEMANTICS, "When condition is accessing its own conditional node value.");
+                ret = LY_EVALID;
+                goto cleanup;
+            }
+        }
+    }
+
+    /* check cyclic dependencies */
+    ret = lys_compile_unres_when_cyclic(&tmp_set, node);
+    LY_CHECK_GOTO(ret, cleanup);
+
+cleanup:
+    lyxp_set_free_content(&tmp_set);
+    return ret;
+}
+
+/**
+ * @brief Check must expressions of a node on a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] node Node to check.
+ * @param[in] local_mods Sized array of local modules for musts of @p node at the same index.
+ * @param[in,out] unres Global unres structure.
+ * @return LY_ERECOMPILE
+ * @return LY_ERR value
+ */
+static LY_ERR
+lys_compile_unres_must(struct lysc_ctx *ctx, const struct lysc_node *node, const struct lysp_module **local_mods,
+        struct lys_glob_unres *unres)
+{
+    struct lyxp_set tmp_set;
+    uint32_t i, opts;
+    LY_ARRAY_COUNT_TYPE u;
+    struct lysc_must *musts = NULL;
+    LY_ERR ret = LY_SUCCESS;
+    const struct lys_module *mod;
+    uint16_t flg;
+
+    LOG_LOCSET(node, NULL, NULL, NULL);
+
+    memset(&tmp_set, 0, sizeof tmp_set);
+    opts = LYXP_SCNODE_SCHEMA | ((node->flags & LYS_IS_OUTPUT) ? LYXP_SCNODE_OUTPUT : 0);
+
+    musts = lysc_node_musts(node);
+    LY_ARRAY_FOR(musts, u) {
+        /* first check whether all the referenced modules are implemented */
+        mod = NULL;
+        ret = lys_compile_expr_implement(ctx->ctx, musts[u].cond, LY_VALUE_SCHEMA_RESOLVED, musts[u].prefixes,
+                ctx->ctx->flags & LY_CTX_REF_IMPLEMENTED, unres, &mod);
+        if (ret) {
+            goto cleanup;
+        } else if (mod) {
+            LOGWRN(ctx->ctx, "Must condition \"%s\" check skipped because referenced module \"%s\" is not implemented.",
+                    musts[u].cond->expr, mod->name);
+            continue;
+        }
+
+        /* check "must" */
+        ret = lyxp_atomize(ctx->ctx, musts[u].cond, node->module, LY_VALUE_SCHEMA_RESOLVED, musts[u].prefixes, node,
+                node, &tmp_set, opts);
+        if (ret) {
+            LOGVAL(ctx->ctx, LYVE_SEMANTICS, "Invalid must condition \"%s\".", musts[u].cond->expr);
+            goto cleanup;
+        }
+
+        ctx->path[0] = '\0';
+        lysc_path(node, LYSC_PATH_LOG, ctx->path, LYSC_CTX_BUFSIZE);
+        for (i = 0; i < tmp_set.used; ++i) {
+            /* skip roots'n'stuff */
+            if (tmp_set.val.scnodes[i].type == LYXP_NODE_ELEM) {
+                struct lysc_node *schema = tmp_set.val.scnodes[i].scnode;
+
+                /* XPath expression cannot reference "lower" status than the node that has the definition */
+                if (local_mods[u]->mod == node->module) {
+                    /* use flags of the context node since the definition is local */
+                    flg = node->flags;
+                } else {
+                    /* definition is foreign (deviation, refine), always current */
+                    flg = LYS_STATUS_CURR;
+                }
+                if (lysc_check_status(NULL, flg, local_mods[u]->mod, node->name, schema->flags, schema->module,
+                        schema->name)) {
+                    LOGWRN(ctx->ctx, "Must condition \"%s\" may be referencing %s node \"%s\".", musts[u].cond->expr,
+                            (schema->flags == LYS_STATUS_OBSLT) ? "obsolete" : "deprecated", schema->name);
+                    break;
+                }
+            }
+        }
+
+        lyxp_set_free_content(&tmp_set);
+    }
+
+cleanup:
+    lyxp_set_free_content(&tmp_set);
+    LOG_LOCBACK(1, 0, 0, 0);
+    return ret;
+}
+
+/**
+ * @brief Remove all disabled bits/enums from a sized array.
+ *
+ * @param[in] ctx Context with the dictionary.
+ * @param[in] items Sized array of bits/enums.
+ */
+static void
+lys_compile_unres_disabled_bitenum_remove(struct lysf_ctx *ctx, struct lysc_type_bitenum_item *items)
+{
+    LY_ARRAY_COUNT_TYPE u = 0, last_u;
+
+    while (u < LY_ARRAY_COUNT(items)) {
+        if (items[u].flags & LYS_DISABLED) {
+            /* free the disabled item */
+            lysc_enum_item_free(ctx, &items[u]);
+
+            /* replace it with the following items */
+            last_u = LY_ARRAY_COUNT(items) - 1;
+            if (u < last_u) {
+                memmove(items + u, items + u + 1, (last_u - u) * sizeof *items);
+            }
+
+            /* one item less */
+            LY_ARRAY_DECREMENT(items);
+            continue;
+        }
+
+        ++u;
+    }
+}
+
+/**
+ * @brief Find and remove all disabled bits/enums in a leaf/leaf-list type.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] leaf Leaf/leaf-list to check.
+ * @return LY_ERR value
+ */
+static LY_ERR
+lys_compile_unres_disabled_bitenum(struct lysc_ctx *ctx, struct lysc_node_leaf *leaf)
+{
+    struct lysc_type **t;
+    LY_ARRAY_COUNT_TYPE u, count;
+    struct lysc_type_enum *ent;
+
+    if (leaf->type->basetype == LY_TYPE_UNION) {
+        t = ((struct lysc_type_union *)leaf->type)->types;
+        count = LY_ARRAY_COUNT(t);
+    } else {
+        t = &leaf->type;
+        count = 1;
+    }
+    for (u = 0; u < count; ++u) {
+        if ((t[u]->basetype == LY_TYPE_BITS) || (t[u]->basetype == LY_TYPE_ENUM)) {
+            /* remove all disabled items */
+            ent = (struct lysc_type_enum *)(t[u]);
+            lys_compile_unres_disabled_bitenum_remove(&ctx->free_ctx, ent->enums);
+
+            if (!LY_ARRAY_COUNT(ent->enums)) {
+                LOGVAL(ctx->ctx, LYVE_SEMANTICS, "%s type of node \"%s\" without any (or all disabled) valid values.",
+                        (ent->basetype == LY_TYPE_BITS) ? "Bits" : "Enumeration", leaf->name);
+                return LY_EVALID;
+            }
+        }
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Check leafref for its target existence on a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] node Context node for the leafref.
+ * @param[in] lref Leafref to check/resolve.
+ * @param[in] local_mod Local module for the leafref type.
+ * @param[in,out] unres Global unres structure.
+ * @return LY_ERECOMPILE if context recompilation is needed,
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_leafref(struct lysc_ctx *ctx, const struct lysc_node *node, struct lysc_type_leafref *lref,
+        const struct lysp_module *local_mod, struct lys_glob_unres *unres)
+{
+    const struct lysc_node *target = NULL;
+    struct ly_path *p;
+    struct lysc_type *type;
+    uint16_t flg;
+
+    assert(node->nodetype & (LYS_LEAF | LYS_LEAFLIST));
+
+    /* first implement all the modules in the path */
+    LY_CHECK_RET(lys_compile_expr_implement(ctx->ctx, lref->path, LY_VALUE_SCHEMA_RESOLVED, lref->prefixes, 1, unres, NULL));
+
+    /* try to find the target, current module is that of the context node (RFC 7950 6.4.1 second bullet) */
+    LY_CHECK_RET(ly_path_compile_leafref(ctx->ctx, node, ctx->ext, lref->path,
+            (node->flags & LYS_IS_OUTPUT) ? LY_PATH_OPER_OUTPUT : LY_PATH_OPER_INPUT, LY_PATH_TARGET_MANY,
+            LY_VALUE_SCHEMA_RESOLVED, lref->prefixes, &p));
+
+    /* get the target node */
+    target = p[LY_ARRAY_COUNT(p) - 1].node;
+    ly_path_free(node->module->ctx, p);
+
+    if (!(target->nodetype & (LYS_LEAF | LYS_LEAFLIST))) {
+        LOGVAL(ctx->ctx, LYVE_REFERENCE, "Invalid leafref path \"%s\" - target node is %s instead of leaf or leaf-list.",
+                lref->path->expr, lys_nodetype2str(target->nodetype));
+        return LY_EVALID;
+    }
+
+    /* check status */
+    ctx->path[0] = '\0';
+    lysc_path(node, LYSC_PATH_LOG, ctx->path, LYSC_CTX_BUFSIZE);
+    ctx->path_len = strlen(ctx->path);
+    if (node->module == local_mod->mod) {
+        /* use flags of the context node since the definition is local */
+        flg = node->flags;
+    } else {
+        /* definition is foreign (deviation), always current */
+        flg = LYS_STATUS_CURR;
+    }
+    if (lysc_check_status(ctx, flg, local_mod->mod, node->name, target->flags, target->module, target->name)) {
+        return LY_EVALID;
+    }
+    ctx->path_len = 1;
+    ctx->path[1] = '\0';
+
+    /* check config */
+    if (lref->require_instance) {
+        if ((node->flags & LYS_CONFIG_W) && (target->flags & LYS_CONFIG_R)) {
+            LOGVAL(ctx->ctx, LYVE_REFERENCE, "Invalid leafref path \"%s\" - target is supposed"
+                    " to represent configuration data (as the leafref does), but it does not.", lref->path->expr);
+            return LY_EVALID;
+        }
+    }
+
+    /* check for circular chain of leafrefs */
+    for (type = ((struct lysc_node_leaf *)target)->type;
+            type && (type->basetype == LY_TYPE_LEAFREF);
+            type = ((struct lysc_type_leafref *)type)->realtype) {
+        if (type == (struct lysc_type *)lref) {
+            /* circular chain detected */
+            LOGVAL(ctx->ctx, LYVE_REFERENCE, "Invalid leafref path \"%s\" - circular chain of leafrefs detected.",
+                    lref->path->expr);
+            return LY_EVALID;
+        }
+    }
+
+    /* store the type */
+    lref->realtype = ((struct lysc_node_leaf *)target)->type;
+    ++lref->realtype->refcount;
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Compile default value(s) for leaf or leaf-list expecting a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] node Leaf or leaf-list to compile the default value(s) for.
+ * @param[in] type Type of the default value.
+ * @param[in] dflt Default value.
+ * @param[in] dflt_pmod Parsed module of the @p dflt to resolve possible prefixes.
+ * @param[in,out] storage Storage for the compiled default value.
+ * @param[in,out] unres Global unres structure for newly implemented modules.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_dflt(struct lysc_ctx *ctx, struct lysc_node *node, struct lysc_type *type, const char *dflt,
+        const struct lysp_module *dflt_pmod, struct lyd_value *storage, struct lys_glob_unres *unres)
+{
+    LY_ERR ret;
+    uint32_t options;
+    struct ly_err_item *err = NULL;
+
+    options = (ctx->ctx->flags & LY_CTX_REF_IMPLEMENTED) ? LYPLG_TYPE_STORE_IMPLEMENT : 0;
+    ret = type->plugin->store(ctx->ctx, type, dflt, strlen(dflt), options, LY_VALUE_SCHEMA, (void *)dflt_pmod,
+            LYD_HINT_SCHEMA, node, storage, unres, &err);
+    if (ret == LY_ERECOMPILE) {
+        /* fine, but we need to recompile */
+        return LY_ERECOMPILE;
+    } else if (ret == LY_EINCOMPLETE) {
+        /* we have no data so we will not be resolving it */
+        ret = LY_SUCCESS;
+    }
+
+    if (ret) {
+        LOG_LOCSET(node, NULL, NULL, NULL);
+        if (err) {
+            LOGVAL(ctx->ctx, LYVE_SEMANTICS, "Invalid default - value does not fit the type (%s).", err->msg);
+            ly_err_free(err);
+        } else {
+            LOGVAL(ctx->ctx, LYVE_SEMANTICS, "Invalid default - value does not fit the type.");
+        }
+        LOG_LOCBACK(1, 0, 0, 0);
+        return ret;
+    }
+
+    LY_ATOMIC_INC_BARRIER(((struct lysc_type *)storage->realtype)->refcount);
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Compile default value of a leaf expecting a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] leaf Leaf that the default value is for.
+ * @param[in] dflt Default value to compile.
+ * @param[in,out] unres Global unres structure for newly implemented modules.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_leaf_dlft(struct lysc_ctx *ctx, struct lysc_node_leaf *leaf, struct lysp_qname *dflt,
+        struct lys_glob_unres *unres)
+{
+    LY_ERR ret;
+
+    assert(!leaf->dflt);
+
+    if (leaf->flags & (LYS_MAND_TRUE | LYS_KEY)) {
+        /* ignore default values for keys and mandatory leaves */
+        return LY_SUCCESS;
+    }
+
+    /* allocate the default value */
+    leaf->dflt = calloc(1, sizeof *leaf->dflt);
+    LY_CHECK_ERR_RET(!leaf->dflt, LOGMEM(ctx->ctx), LY_EMEM);
+
+    /* store the default value */
+    ret = lys_compile_unres_dflt(ctx, &leaf->node, leaf->type, dflt->str, dflt->mod, leaf->dflt, unres);
+    if (ret) {
+        free(leaf->dflt);
+        leaf->dflt = NULL;
+    }
+
+    return ret;
+}
+
+/**
+ * @brief Compile default values of a leaf-list expecting a complete compiled schema tree.
+ *
+ * @param[in] ctx Compile context.
+ * @param[in] llist Leaf-list that the default value(s) are for.
+ * @param[in] dflt Default value to compile, in case of a single value.
+ * @param[in] dflts Sized array of default values, in case of more values.
+ * @param[in,out] unres Global unres structure for newly implemented modules.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_llist_dflts(struct lysc_ctx *ctx, struct lysc_node_leaflist *llist, struct lysp_qname *dflt,
+        struct lysp_qname *dflts, struct lys_glob_unres *unres)
+{
+    LY_ERR ret;
+    LY_ARRAY_COUNT_TYPE orig_count, u, v;
+
+    assert(dflt || dflts);
+
+    /* in case there were already some defaults and we are adding new by deviations */
+    orig_count = LY_ARRAY_COUNT(llist->dflts);
+
+    /* allocate new items */
+    LY_ARRAY_CREATE_RET(ctx->ctx, llist->dflts, orig_count + (dflts ? LY_ARRAY_COUNT(dflts) : 1), LY_EMEM);
+
+    /* fill each new default value */
+    if (dflts) {
+        LY_ARRAY_FOR(dflts, u) {
+            llist->dflts[orig_count + u] = calloc(1, sizeof **llist->dflts);
+            ret = lys_compile_unres_dflt(ctx, &llist->node, llist->type, dflts[u].str, dflts[u].mod,
+                    llist->dflts[orig_count + u], unres);
+            LY_CHECK_ERR_RET(ret, free(llist->dflts[orig_count + u]), ret);
+            LY_ARRAY_INCREMENT(llist->dflts);
+        }
+    } else {
+        llist->dflts[orig_count] = calloc(1, sizeof **llist->dflts);
+        ret = lys_compile_unres_dflt(ctx, &llist->node, llist->type, dflt->str, dflt->mod,
+                llist->dflts[orig_count], unres);
+        LY_CHECK_ERR_RET(ret, free(llist->dflts[orig_count]), ret);
+        LY_ARRAY_INCREMENT(llist->dflts);
+    }
+
+    /* check default value uniqueness */
+    if (llist->flags & LYS_CONFIG_W) {
+        /* configuration data values must be unique - so check the default values */
+        for (u = orig_count; u < LY_ARRAY_COUNT(llist->dflts); ++u) {
+            for (v = 0; v < u; ++v) {
+                if (!llist->dflts[u]->realtype->plugin->compare(llist->dflts[u], llist->dflts[v])) {
+                    lysc_update_path(ctx, llist->parent ? llist->parent->module : NULL, llist->name);
+                    LOGVAL(ctx->ctx, LYVE_SEMANTICS, "Configuration leaf-list has multiple defaults of the same value \"%s\".",
+                            llist->dflts[u]->realtype->plugin->print(ctx->ctx, llist->dflts[u], LY_VALUE_CANON, NULL, NULL, NULL));
+                    lysc_update_path(ctx, NULL, NULL);
+                    return LY_EVALID;
+                }
+            }
+        }
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Iteratively get all leafrefs from @p node
+ * if the node is of type union, otherwise just return the leafref.
+ *
+ * @param[in] node Node that may contain the leafref.
+ * @param[in,out] index Value that is passed between function calls.
+ * For each new node, initialize value of the @p index to 0, otherwise
+ * do not modify the value between calls.
+ * @return Pointer to the leafref or next leafref, otherwise NULL.
+ */
+static struct lysc_type_leafref *
+lys_type_leafref_next(const struct lysc_node *node, uint64_t *index)
+{
+    struct lysc_type_leafref *ret = NULL;
+    struct lysc_type_union *uni;
+    struct lysc_type *leaf_type;
+
+    assert(node->nodetype & LYD_NODE_TERM);
+
+    leaf_type = ((struct lysc_node_leaf *)node)->type;
+    if (leaf_type->basetype == LY_TYPE_UNION) {
+        uni = (struct lysc_type_union *)leaf_type;
+
+        /* find next union leafref */
+        while (*index < LY_ARRAY_COUNT(uni->types)) {
+            if (uni->types[*index]->basetype == LY_TYPE_LEAFREF) {
+                ret = (struct lysc_type_leafref *)uni->types[*index];
+                ++(*index);
+                break;
+            }
+
+            ++(*index);
+        }
+    } else {
+        /* return just the single leafref */
+        if (*index == 0) {
+            ++(*index);
+            assert(leaf_type->basetype == LY_TYPE_LEAFREF);
+            ret = (struct lysc_type_leafref *)leaf_type;
+        }
+    }
+
+    return ret;
+}
+
+/**
+ * @brief Finish dependency set compilation by resolving all the unres sets.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] unres Global unres structure with the sets to resolve.
+ * @return LY_SUCCESS on success.
+ * @return LY_ERECOMPILE if the dep set needs to be recompiled.
+ * @return LY_ERR value on error.
+ */
+static LY_ERR
+lys_compile_unres_depset(struct ly_ctx *ctx, struct lys_glob_unres *unres)
+{
+    LY_ERR ret = LY_SUCCESS, r;
+    struct lysc_node *node;
+    struct lysc_type *typeiter;
+    struct lysc_type_leafref *lref;
+    struct lysc_ctx cctx = {0};
+    struct lys_depset_unres *ds_unres = &unres->ds_unres;
+    struct ly_path *path;
+    LY_ARRAY_COUNT_TYPE v;
+    struct lysc_unres_leafref *l;
+    struct lysc_unres_when *w;
+    struct lysc_unres_must *m;
+    struct lysc_unres_dflt *d;
+    uint32_t i, processed_leafrefs = 0;
+
+resolve_all:
+    /* check disabled leafrefs first */
+    while (ds_unres->disabled_leafrefs.count) {
+        /* remember index, it can change before we get to free this item */
+        i = ds_unres->disabled_leafrefs.count - 1;
+        l = ds_unres->disabled_leafrefs.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, l->node->module->parsed, l->ext);
+
+        LOG_LOCSET(l->node, NULL, NULL, NULL);
+        v = 0;
+        while ((ret == LY_SUCCESS) && (lref = lys_type_leafref_next(l->node, &v))) {
+            ret = lys_compile_unres_leafref(&cctx, l->node, lref, l->local_mod, unres);
+        }
+        LOG_LOCBACK(1, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+
+        ly_set_rm_index(&ds_unres->disabled_leafrefs, i, free);
+    }
+
+    /* for leafref, we need 2 rounds - first detects circular chain by storing the first referred type (which
+     * can be also leafref, in case it is already resolved, go through the chain and check that it does not
+     * point to the starting leafref type). The second round stores the first non-leafref type for later data validation.
+     * Also do the same check for set of the disabled leafrefs, but without the second round. */
+    for (i = processed_leafrefs; i < ds_unres->leafrefs.count; ++i) {
+        l = ds_unres->leafrefs.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, l->node->module->parsed, l->ext);
+
+        LOG_LOCSET(l->node, NULL, NULL, NULL);
+        v = 0;
+        while ((ret == LY_SUCCESS) && (lref = lys_type_leafref_next(l->node, &v))) {
+            ret = lys_compile_unres_leafref(&cctx, l->node, lref, l->local_mod, unres);
+        }
+        LOG_LOCBACK(1, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+    }
+    for (i = processed_leafrefs; i < ds_unres->leafrefs.count; ++i) {
+        l = ds_unres->leafrefs.objs[i];
+
+        /* store pointer to the real type */
+        v = 0;
+        while ((lref = lys_type_leafref_next(l->node, &v))) {
+            for (typeiter = lref->realtype;
+                    typeiter->basetype == LY_TYPE_LEAFREF;
+                    typeiter = ((struct lysc_type_leafref *)typeiter)->realtype) {}
+
+            lysc_type_free(&cctx.free_ctx, lref->realtype);
+            lref->realtype = typeiter;
+            ++lref->realtype->refcount;
+        }
+
+        /* if 'goto' will be used on the 'resolve_all' label, then the current leafref will not be processed again */
+        processed_leafrefs++;
+    }
+
+    /* check when, first implement all the referenced modules (for the cyclic check in the next loop to work) */
+    i = 0;
+    while (i < ds_unres->whens.count) {
+        w = ds_unres->whens.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, w->node->module->parsed, NULL);
+
+        LOG_LOCSET(w->node, NULL, NULL, NULL);
+        r = lys_compile_unres_when_implement(&cctx, w->when, unres);
+        LOG_LOCBACK(w->node ? 1 : 0, 0, 0, 0);
+
+        if (r == LY_ENOT) {
+            /* skip full when check, remove from the set */
+            free(w);
+            ly_set_rm_index(&ds_unres->whens, i, NULL);
+            continue;
+        } else if (r) {
+            /* error */
+            ret = r;
+            goto cleanup;
+        }
+
+        ++i;
+    }
+    while (ds_unres->whens.count) {
+        i = ds_unres->whens.count - 1;
+        w = ds_unres->whens.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, w->node->module->parsed, NULL);
+
+        LOG_LOCSET(w->node, NULL, NULL, NULL);
+        ret = lys_compile_unres_when(&cctx, w->when, w->node);
+        LOG_LOCBACK(w->node ? 1 : 0, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+
+        free(w);
+        ly_set_rm_index(&ds_unres->whens, i, NULL);
+    }
+
+    /* check must */
+    while (ds_unres->musts.count) {
+        i = ds_unres->musts.count - 1;
+        m = ds_unres->musts.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, m->node->module->parsed, m->ext);
+
+        LOG_LOCSET(m->node, NULL, NULL, NULL);
+        ret = lys_compile_unres_must(&cctx, m->node, m->local_mods, unres);
+        LOG_LOCBACK(1, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+
+        lysc_unres_must_free(m);
+        ly_set_rm_index(&ds_unres->musts, i, NULL);
+    }
+
+    /* remove disabled enums/bits */
+    while (ds_unres->disabled_bitenums.count) {
+        i = ds_unres->disabled_bitenums.count - 1;
+        node = ds_unres->disabled_bitenums.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, node->module->parsed, NULL);
+
+        LOG_LOCSET(node, NULL, NULL, NULL);
+        ret = lys_compile_unres_disabled_bitenum(&cctx, (struct lysc_node_leaf *)node);
+        LOG_LOCBACK(1, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+
+        ly_set_rm_index(&ds_unres->disabled_bitenums, i, NULL);
+    }
+
+    /* finish incomplete default values compilation */
+    while (ds_unres->dflts.count) {
+        i = ds_unres->dflts.count - 1;
+        d = ds_unres->dflts.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, d->leaf->module->parsed, NULL);
+
+        LOG_LOCSET(&d->leaf->node, NULL, NULL, NULL);
+        if (d->leaf->nodetype == LYS_LEAF) {
+            ret = lys_compile_unres_leaf_dlft(&cctx, d->leaf, d->dflt, unres);
+        } else {
+            ret = lys_compile_unres_llist_dflts(&cctx, d->llist, d->dflt, d->dflts, unres);
+        }
+        LOG_LOCBACK(1, 0, 0, 0);
+        LY_CHECK_GOTO(ret, cleanup);
+
+        lysc_unres_dflt_free(ctx, d);
+        ly_set_rm_index(&ds_unres->dflts, i, NULL);
+    }
+
+    /* some unres items may have been added */
+    if ((processed_leafrefs != ds_unres->leafrefs.count) || ds_unres->disabled_leafrefs.count ||
+            ds_unres->whens.count || ds_unres->musts.count || ds_unres->dflts.count) {
+        goto resolve_all;
+    }
+
+    /* finally, remove all disabled nodes */
+    for (i = 0; i < ds_unres->disabled.count; ++i) {
+        node = ds_unres->disabled.snodes[i];
+        if (node->flags & LYS_KEY) {
+            LOG_LOCSET(node, NULL, NULL, NULL);
+            LOGVAL(ctx, LYVE_REFERENCE, "Key \"%s\" is disabled.", node->name);
+            LOG_LOCBACK(1, 0, 0, 0);
+            ret = LY_EVALID;
+            goto cleanup;
+        }
+        LYSC_CTX_INIT_PMOD(cctx, node->module->parsed, NULL);
+
+        lysc_node_free(&cctx.free_ctx, node, 1);
+    }
+
+    /* also check if the leafref target has not been disabled */
+    for (i = 0; i < ds_unres->leafrefs.count; ++i) {
+        l = ds_unres->leafrefs.objs[i];
+        LYSC_CTX_INIT_PMOD(cctx, l->node->module->parsed, l->ext);
+
+        v = 0;
+        while ((lref = lys_type_leafref_next(l->node, &v))) {
+            ret = ly_path_compile_leafref(cctx.ctx, l->node, cctx.ext, lref->path,
+                    (l->node->flags & LYS_IS_OUTPUT) ? LY_PATH_OPER_OUTPUT : LY_PATH_OPER_INPUT, LY_PATH_TARGET_MANY,
+                    LY_VALUE_SCHEMA_RESOLVED, lref->prefixes, &path);
+            ly_path_free(l->node->module->ctx, path);
+
+            assert(ret != LY_ERECOMPILE);
+            if (ret) {
+                LOG_LOCSET(l->node, NULL, NULL, NULL);
+                LOGVAL(ctx, LYVE_REFERENCE, "Target of leafref \"%s\" cannot be referenced because it is disabled.",
+                        l->node->name);
+                LOG_LOCBACK(1, 0, 0, 0);
+                ret = LY_EVALID;
+                goto cleanup;
+            }
+        }
+    }
+
+cleanup:
+    lysf_ctx_erase(&cctx.free_ctx);
+    return ret;
+}
+
+/**
+ * @brief Erase dep set unres.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] unres Global unres structure with the sets to resolve.
+ */
+static void
+lys_compile_unres_depset_erase(const struct ly_ctx *ctx, struct lys_glob_unres *unres)
+{
+    uint32_t i;
+
+    ly_set_erase(&unres->ds_unres.whens, free);
+    for (i = 0; i < unres->ds_unres.musts.count; ++i) {
+        lysc_unres_must_free(unres->ds_unres.musts.objs[i]);
+    }
+    ly_set_erase(&unres->ds_unres.musts, NULL);
+    ly_set_erase(&unres->ds_unres.leafrefs, free);
+    for (i = 0; i < unres->ds_unres.dflts.count; ++i) {
+        lysc_unres_dflt_free(ctx, unres->ds_unres.dflts.objs[i]);
+    }
+    ly_set_erase(&unres->ds_unres.dflts, NULL);
+    ly_set_erase(&unres->ds_unres.disabled, NULL);
+    ly_set_erase(&unres->ds_unres.disabled_leafrefs, free);
+    ly_set_erase(&unres->ds_unres.disabled_bitenums, NULL);
+}
+
+/**
+ * @brief Compile all flagged modules in a dependency set, recursively if recompilation is needed.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] dep_set Dependency set to compile.
+ * @param[in,out] unres Global unres to use.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_depset_r(struct ly_ctx *ctx, struct ly_set *dep_set, struct lys_glob_unres *unres)
+{
+    LY_ERR ret = LY_SUCCESS;
+    struct lysf_ctx fctx = {.ctx = ctx};
+    struct lys_module *mod;
+    uint32_t i;
+
+    for (i = 0; i < dep_set->count; ++i) {
+        mod = dep_set->objs[i];
+        if (!mod->to_compile) {
+            /* skip */
+            continue;
+        }
+        assert(mod->implemented);
+
+        /* free the compiled module, if any */
+        lysc_module_free(&fctx, mod->compiled);
+        mod->compiled = NULL;
+
+        /* (re)compile the module */
+        LY_CHECK_GOTO(ret = lys_compile(mod, &unres->ds_unres), cleanup);
+    }
+
+    /* resolve dep set unres */
+    ret = lys_compile_unres_depset(ctx, unres);
+    if (ret == LY_ERECOMPILE) {
+        /* new module is implemented, discard current dep set unres and recompile the whole dep set */
+        lys_compile_unres_depset_erase(ctx, unres);
+        return lys_compile_depset_r(ctx, dep_set, unres);
+    } else if (ret) {
+        /* error */
+        goto cleanup;
+    }
+
+    /* success, unset the flags of all the modules in the dep set */
+    for (i = 0; i < dep_set->count; ++i) {
+        mod = dep_set->objs[i];
+        mod->to_compile = 0;
+    }
+
+cleanup:
+    lys_compile_unres_depset_erase(ctx, unres);
+    lysf_ctx_erase(&fctx);
+    return ret;
+}
+
+/**
+ * @brief Check if-feature of all features of all modules in a dep set.
+ *
+ * @param[in] dep_set Dep set to check.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_depset_check_features(struct ly_set *dep_set)
+{
+    struct lys_module *mod;
+    uint32_t i;
+
+    for (i = 0; i < dep_set->count; ++i) {
+        mod = dep_set->objs[i];
+        if (!mod->to_compile) {
+            /* skip */
+            continue;
+        }
+
+        /* check features of this module */
+        LY_CHECK_RET(lys_check_features(mod->parsed));
+    }
+
+    return LY_SUCCESS;
+}
+
+LY_ERR
+lys_compile_depset_all(struct ly_ctx *ctx, struct lys_glob_unres *unres)
+{
+    uint32_t i;
+
+    for (i = 0; i < unres->dep_sets.count; ++i) {
+        LY_CHECK_RET(lys_compile_depset_check_features(unres->dep_sets.objs[i]));
+        LY_CHECK_RET(lys_compile_depset_r(ctx, unres->dep_sets.objs[i], unres));
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Finish compilation of all the module unres sets in a compile context.
+ *
+ * @param[in] ctx Compile context with unres sets.
+ * @return LY_ERR value.
+ */
+static LY_ERR
+lys_compile_unres_mod(struct lysc_ctx *ctx)
+{
+    struct lysc_augment *aug;
+    struct lysc_deviation *dev;
+    struct lys_module *orig_mod = ctx->cur_mod;
+    uint32_t i;
+
+    /* check that all augments were applied */
+    for (i = 0; i < ctx->augs.count; ++i) {
+        aug = ctx->augs.objs[i];
+        ctx->cur_mod = aug->aug_pmod->mod;
+        if (aug->ext) {
+            lysc_update_path(ctx, NULL, "{extension}");
+            lysc_update_path(ctx, NULL, aug->ext->name);
+        }
+        lysc_update_path(ctx, NULL, "{augment}");
+        lysc_update_path(ctx, NULL, aug->nodeid->expr);
+        LOGVAL(ctx->ctx, LYVE_REFERENCE, "Augment%s target node \"%s\" from module \"%s\" was not found.",
+                aug->ext ? " extension" : "", aug->nodeid->expr, LYSP_MODULE_NAME(aug->aug_pmod));
+        ctx->cur_mod = orig_mod;
+        lysc_update_path(ctx, NULL, NULL);
+        lysc_update_path(ctx, NULL, NULL);
+        if (aug->ext) {
+            lysc_update_path(ctx, NULL, NULL);
+            lysc_update_path(ctx, NULL, NULL);
+        }
+    }
+    if (ctx->augs.count) {
+        return LY_ENOTFOUND;
+    }
+
+    /* check that all deviations were applied */
+    for (i = 0; i < ctx->devs.count; ++i) {
+        dev = ctx->devs.objs[i];
+        lysc_update_path(ctx, NULL, "{deviation}");
+        lysc_update_path(ctx, NULL, dev->nodeid->expr);
+        LOGVAL(ctx->ctx, LYVE_REFERENCE, "Deviation(s) target node \"%s\" from module \"%s\" was not found.",
+                dev->nodeid->expr, LYSP_MODULE_NAME(dev->dev_pmods[0]));
+        lysc_update_path(ctx, NULL, NULL);
+        lysc_update_path(ctx, NULL, NULL);
+    }
+    if (ctx->devs.count) {
+        return LY_ENOTFOUND;
+    }
+
+    return LY_SUCCESS;
+}
+
+/**
+ * @brief Erase all the module unres sets in a compile context.
+ *
+ * @param[in] ctx Compile context with unres sets.
+ * @param[in] error Whether the compilation finished with an error or not.
+ */
+static void
+lys_compile_unres_mod_erase(struct lysc_ctx *ctx, ly_bool error)
+{
+    uint32_t i;
+
+    ly_set_erase(&ctx->groupings, NULL);
+    ly_set_erase(&ctx->tpdf_chain, NULL);
+
+    if (!error) {
+        /* there can be no leftover deviations or augments */
+        LY_CHECK_ERR_RET(ctx->augs.count, LOGINT(ctx->ctx), );
+        LY_CHECK_ERR_RET(ctx->devs.count, LOGINT(ctx->ctx), );
+
+        ly_set_erase(&ctx->augs, NULL);
+        ly_set_erase(&ctx->devs, NULL);
+        ly_set_erase(&ctx->uses_augs, NULL);
+        ly_set_erase(&ctx->uses_rfns, NULL);
+    } else {
+        for (i = 0; i < ctx->augs.count; ++i) {
+            lysc_augment_free(ctx->ctx, ctx->augs.objs[i]);
+        }
+        ly_set_erase(&ctx->augs, NULL);
+        for (i = 0; i < ctx->devs.count; ++i) {
+            lysc_deviation_free(ctx->ctx, ctx->devs.objs[i]);
+        }
+        ly_set_erase(&ctx->devs, NULL);
+        for (i = 0; i < ctx->uses_augs.count; ++i) {
+            lysc_augment_free(ctx->ctx, ctx->uses_augs.objs[i]);
+        }
+        ly_set_erase(&ctx->uses_augs, NULL);
+        for (i = 0; i < ctx->uses_rfns.count; ++i) {
+            lysc_refine_free(ctx->ctx, ctx->uses_rfns.objs[i]);
+        }
+        ly_set_erase(&ctx->uses_rfns, NULL);
+    }
+}
+
+LY_ERR
+lys_compile(struct lys_module *mod, struct lys_depset_unres *unres)
+{
+    struct lysc_ctx ctx;
+    struct lysc_module *mod_c = NULL;
+    struct lysp_module *sp;
+    struct lysp_submodule *submod;
+    struct lysp_node *pnode;
+    struct lysp_node_grp *grp;
+    LY_ARRAY_COUNT_TYPE u;
+    LY_ERR ret = LY_SUCCESS;
+
+    LY_CHECK_ARG_RET(NULL, mod, mod->parsed, !mod->compiled, mod->ctx, LY_EINVAL);
+
+    assert(mod->implemented && mod->to_compile);
+
+    sp = mod->parsed;
+    LYSC_CTX_INIT_PMOD(ctx, sp, NULL);
+    ctx.unres = unres;
+
+    ++mod->ctx->change_count;
+    mod->compiled = mod_c = calloc(1, sizeof *mod_c);
+    LY_CHECK_ERR_RET(!mod_c, LOGMEM(mod->ctx), LY_EMEM);
+    mod_c->mod = mod;
+
+    /* compile augments and deviations of our module from other modules so they can be applied during compilation */
+    LY_CHECK_GOTO(ret = lys_precompile_own_augments(&ctx), cleanup);
+    LY_CHECK_GOTO(ret = lys_precompile_own_deviations(&ctx), cleanup);
+
+    /* data nodes */
+    LY_LIST_FOR(sp->data, pnode) {
+        LY_CHECK_GOTO(ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL), cleanup);
+    }
+
+    /* top-level RPCs */
+    LY_LIST_FOR((struct lysp_node *)sp->rpcs, pnode) {
+        LY_CHECK_GOTO(ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL), cleanup);
+    }
+
+    /* top-level notifications */
+    LY_LIST_FOR((struct lysp_node *)sp->notifs, pnode) {
+        LY_CHECK_GOTO(ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL), cleanup);
+    }
+
+    /* module extension instances */
+    COMPILE_EXTS_GOTO(&ctx, sp->exts, mod_c->exts, mod_c, ret, cleanup);
+
+    /* the same for submodules */
+    LY_ARRAY_FOR(sp->includes, u) {
+        submod = sp->includes[u].submodule;
+        ctx.pmod = (struct lysp_module *)submod;
+
+        LY_LIST_FOR(submod->data, pnode) {
+            ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL);
+            LY_CHECK_GOTO(ret, cleanup);
+        }
+
+        LY_LIST_FOR((struct lysp_node *)submod->rpcs, pnode) {
+            ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL);
+            LY_CHECK_GOTO(ret, cleanup);
+        }
+
+        LY_LIST_FOR((struct lysp_node *)submod->notifs, pnode) {
+            ret = lys_compile_node(&ctx, pnode, NULL, 0, NULL);
+            LY_CHECK_GOTO(ret, cleanup);
+        }
+
+        COMPILE_EXTS_GOTO(&ctx, submod->exts, mod_c->exts, mod_c, ret, cleanup);
+    }
+    ctx.pmod = sp;
+
+    /* validate non-instantiated groupings from the parsed schema,
+     * without it we would accept even the schemas with invalid grouping specification */
+    ctx.compile_opts |= LYS_COMPILE_GROUPING;
+    LY_LIST_FOR(sp->groupings, grp) {
+        if (!(grp->flags & LYS_USED_GRP)) {
+            LY_CHECK_GOTO(ret = lys_compile_grouping(&ctx, NULL, grp), cleanup);
+        }
+    }
+    LY_LIST_FOR(sp->data, pnode) {
+        LY_LIST_FOR((struct lysp_node_grp *)lysp_node_groupings(pnode), grp) {
+            if (!(grp->flags & LYS_USED_GRP)) {
+                LY_CHECK_GOTO(ret = lys_compile_grouping(&ctx, pnode, grp), cleanup);
+            }
+        }
+    }
+    LY_ARRAY_FOR(sp->includes, u) {
+        submod = sp->includes[u].submodule;
+        ctx.pmod = (struct lysp_module *)submod;
+
+        LY_LIST_FOR(submod->groupings, grp) {
+            if (!(grp->flags & LYS_USED_GRP)) {
+                LY_CHECK_GOTO(ret = lys_compile_grouping(&ctx, NULL, grp), cleanup);
+            }
+        }
+        LY_LIST_FOR(submod->data, pnode) {
+            LY_LIST_FOR((struct lysp_node_grp *)lysp_node_groupings(pnode), grp) {
+                if (!(grp->flags & LYS_USED_GRP)) {
+                    LY_CHECK_GOTO(ret = lys_compile_grouping(&ctx, pnode, grp), cleanup);
+                }
+            }
+        }
+    }
+    ctx.pmod = sp;
+
+    LOG_LOCBACK(0, 0, 1, 0);
+
+    /* finish compilation for all unresolved module items in the context */
+    LY_CHECK_GOTO(ret = lys_compile_unres_mod(&ctx), cleanup);
+
+cleanup:
+    LOG_LOCBACK(0, 0, 1, 0);
+    lys_compile_unres_mod_erase(&ctx, ret);
+    if (ret) {
+        lysc_module_free(&ctx.free_ctx, mod_c);
+        mod->compiled = NULL;
+    }
+    return ret;
+}
+
+LY_ERR
+lys_compile_identities(struct lys_module *mod)
+{
+    LY_ERR rc = LY_SUCCESS;
+    struct lysc_ctx ctx;
+    struct lysp_submodule *submod;
+    LY_ARRAY_COUNT_TYPE u;
+
+    /* pre-compile identities of the module and any submodules */
+    rc = lys_identity_precompile(NULL, mod->ctx, mod->parsed, mod->parsed->identities, &mod->identities);
+    LY_CHECK_GOTO(rc, cleanup);
+    LY_ARRAY_FOR(mod->parsed->includes, u) {
+        submod = mod->parsed->includes[u].submodule;
+        rc = lys_identity_precompile(NULL, mod->ctx, (struct lysp_module *)submod, submod->identities, &mod->identities);
+        LY_CHECK_GOTO(rc, cleanup);
+    }
+
+    /* prepare context */
+    LYSC_CTX_INIT_PMOD(ctx, mod->parsed, NULL);
+
+    if (mod->parsed->identities) {
+        rc = lys_compile_identities_derived(&ctx, mod->parsed->identities, &mod->identities);
+        LY_CHECK_GOTO(rc, cleanup);
+    }
+    lysc_update_path(&ctx, NULL, "{submodule}");
+    LY_ARRAY_FOR(mod->parsed->includes, u) {
+        submod = mod->parsed->includes[u].submodule;
+        if (submod->identities) {
+            ctx.pmod = (struct lysp_module *)submod;
+            lysc_update_path(&ctx, NULL, submod->name);
+            rc = lys_compile_identities_derived(&ctx, submod->identities, &mod->identities);
+            lysc_update_path(&ctx, NULL, NULL);
+        }
+
+        if (rc) {
+            break;
+        }
+    }
+    lysc_update_path(&ctx, NULL, NULL);
+
+cleanup:
+    /* always needed when using lysc_update_path() */
+    LOG_LOCBACK(0, 0, 1, 0);
+    return rc;
+}
+
+/**
+ * @brief Check whether a module does not have any (recursive) compiled import.
+ *
+ * @param[in] mod Module to examine.
+ * @return LY_SUCCESS on success.
+ * @return LY_ERECOMPILE on required recompilation of the dep set.
+ * @return LY_ERR on error.
+ */
+static LY_ERR
+lys_has_compiled_import_r(struct lys_module *mod)
+{
+    LY_ARRAY_COUNT_TYPE u;
+    struct lys_module *m;
+
+    LY_ARRAY_FOR(mod->parsed->imports, u) {
+        m = mod->parsed->imports[u].module;
+        if (!m->implemented) {
+            continue;
+        }
+
+        if (!m->to_compile) {
+            /* module was not/will not be compiled in this compilation (so disabled nodes are not present) */
+            m->to_compile = 1;
+            return LY_ERECOMPILE;
+        }
+
+        /* recursive */
+        LY_CHECK_RET(lys_has_compiled_import_r(m));
+    }
+
+    return LY_SUCCESS;
+}
+
+LY_ERR
+lys_implement(struct lys_module *mod, const char **features, struct lys_glob_unres *unres)
+{
+    LY_ERR ret;
+    struct lys_module *m;
+
+    assert(!mod->implemented);
+
+    /* check collision with other implemented revision */
+    m = ly_ctx_get_module_implemented(mod->ctx, mod->name);
+    if (m) {
+        assert(m != mod);
+        if (!strcmp(mod->name, "yang") && (strcmp(m->revision, mod->revision) > 0)) {
+            /* special case for newer internal module, continue */
+            LOGVRB("Internal module \"%s@%s\" is already implemented in revision \"%s\", using it instead.",
+                    mod->name, mod->revision ? mod->revision : "<none>", m->revision ? m->revision : "<none>");
+        } else {
+            LOGERR(mod->ctx, LY_EDENIED, "Module \"%s@%s\" is already implemented in revision \"%s\".",
+                    mod->name, mod->revision ? mod->revision : "<none>", m->revision ? m->revision : "<none>");
+            return LY_EDENIED;
+        }
+    }
+
+    /* set features */
+    ret = lys_set_features(mod->parsed, features);
+    if (ret && (ret != LY_EEXIST)) {
+        return ret;
+    }
+
+    /*
+     * mark the module implemented, which means
+     * 1) to (re)compile it only ::lys_compile() call is needed
+     * 2) its compilation will never cause new modules to be implemented (::lys_compile() does not return ::LY_ERECOMPILE)
+     *    but there can be some unres items added that do
+     */
+    mod->implemented = 1;
+
+    /* this module is compiled in this compilation */
+    mod->to_compile = 1;
+
+    /* add the module into newly implemented module set */
+    LY_CHECK_RET(ly_set_add(&unres->implementing, mod, 1, NULL));
+
+    /* mark target modules with our augments and deviations */
+    LY_CHECK_RET(lys_precompile_augments_deviations(mod, unres));
+
+    /* check whether this module may reference any modules compiled previously */
+    LY_CHECK_RET(lys_has_compiled_import_r(mod));
+
+    return LY_SUCCESS;
+}