plugins exts CHANGE ext parsing isolated into a callback

Lots of refactoring and finishing up included.
diff --git a/src/plugins_exts/metadata.c b/src/plugins_exts/metadata.c
index f6e1580..fc49e2c 100644
--- a/src/plugins_exts/metadata.c
+++ b/src/plugins_exts/metadata.c
@@ -1,9 +1,10 @@
 /**
  * @file metadata.c
  * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @author Michal Vasko <mvasko@cesnet.cz>
  * @brief libyang extension plugin - Metadata (RFC 7952)
  *
- * Copyright (c) 2019 CESNET, z.s.p.o.
+ * Copyright (c) 2019 - 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.
@@ -21,93 +22,150 @@
 #include "libyang.h"
 #include "plugins_exts.h"
 
-/**
- * @brief Representation of the compiled metadata substatements - simplify storage for the items available via
- * ::lysc_ext_substmt.
- */
-struct lyext_metadata {
-    struct lysc_type *type;            /**< type of the metadata (mandatory) */
+struct lysp_ext_metadata {
+    struct lysp_type *type;            /**< type of the metadata (mandatory) */
     const char *units;                 /**< units of the leaf's type */
-    struct lysc_iffeature *iffeatures; /**< list of if-feature expressions ([sized array](@ref sizedarrays)) */
+    struct lysp_qname *iffeatures;     /**< list of if-feature expressions ([sized array](@ref sizedarrays)) */
     const char *dsc;                   /**< description */
     const char *ref;                   /**< reference */
     uint16_t flags;                    /**< [schema node flags](@ref snodeflags) - only LYS_STATUS_* values are allowed */
 };
 
+struct lysc_ext_metadata {
+    struct lysc_type *type;            /**< type of the metadata (mandatory) */
+    const char *units;                 /**< units of the leaf's type */
+    const char *dsc;                   /**< description */
+    const char *ref;                   /**< reference */
+    uint16_t flags;                    /**< [schema node flags](@ref snodeflags) - only LYS_STATUS_* values are allowed */
+};
+
+/**
+ * @brief Parse annotation extension instances.
+ *
+ * Implementation of ::lyplg_ext_parse_clb callback set as lyext_plugin::parse.
+ */
+static LY_ERR
+annotation_parse(struct lysp_ctx *pctx, struct lysp_ext_instance *ext)
+{
+    LY_ERR r;
+    struct lysp_ext_metadata *ann_pdata;
+    struct lysp_module *pmod;
+    LY_ARRAY_COUNT_TYPE u;
+
+    /* annotations can appear only at the top level of a YANG module or submodule */
+    if ((ext->parent_stmt != LY_STMT_MODULE) && (ext->parent_stmt != LY_STMT_SUBMODULE)) {
+        lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EVALID, "Extension %s is allowed only at the top level of a YANG module or "
+                "submodule, but it is placed in \"%s\" statement.", ext->name, lyplg_ext_stmt2str(ext->parent_stmt));
+        return LY_EVALID;
+    }
+
+    pmod = ext->parent;
+
+    /* check for duplication */
+    LY_ARRAY_FOR(pmod->exts, u) {
+        if ((&pmod->exts[u] != ext) && (pmod->exts[u].name == ext->name) && !strcmp(pmod->exts[u].argument, ext->argument)) {
+            /* duplication of the same annotation extension in a single module */
+            lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EVALID, "Extension %s is instantiated multiple times.", ext->name);
+            return LY_EVALID;
+        }
+    }
+
+    /* parse annotation substatements */
+    ext->parsed = ann_pdata = calloc(1, sizeof *ann_pdata);
+    if (!ann_pdata) {
+        goto emem;
+    }
+    LY_ARRAY_CREATE_GOTO(lyplg_extp_cur_pmod(pctx)->mod->ctx, ext->substmts, 6, r, emem);
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[0].stmt = LY_STMT_IF_FEATURE;
+    ext->substmts[0].storage = &ann_pdata->iffeatures;
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[1].stmt = LY_STMT_UNITS;
+    ext->substmts[1].storage = &ann_pdata->units;
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[2].stmt = LY_STMT_STATUS;
+    ext->substmts[2].storage = &ann_pdata->flags;
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[3].stmt = LY_STMT_TYPE;
+    ext->substmts[3].storage = &ann_pdata->type;
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[4].stmt = LY_STMT_DESCRIPTION;
+    ext->substmts[4].storage = &ann_pdata->dsc;
+
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[5].stmt = LY_STMT_REFERENCE;
+    ext->substmts[5].storage = &ann_pdata->ref;
+
+    if ((r = lyplg_ext_parse_extension_instance(pctx, ext))) {
+        return r;
+    }
+
+    /* check for mandatory substatements */
+    if (!ann_pdata->type) {
+        lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EVALID, "Missing mandatory keyword \"type\" as a child of \"%s %s\".",
+                ext->name, ext->argument);
+        return LY_EVALID;
+    }
+
+    return LY_SUCCESS;
+
+emem:
+    lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EMEM, "Memory allocation failed (%s()).", __func__);
+    return LY_EMEM;
+}
+
 /**
  * @brief Compile annotation extension instances.
  *
  * Implementation of ::lyplg_ext_compile_clb callback set as lyext_plugin::compile.
  */
 static LY_ERR
-annotation_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *p_ext, struct lysc_ext_instance *c_ext)
+annotation_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *extp, struct lysc_ext_instance *ext)
 {
     LY_ERR ret;
-    struct lyext_metadata *annotation;
-    struct lysc_module *mod_c;
-    LY_ARRAY_COUNT_TYPE u;
-
-    /* annotations can appear only at the top level of a YANG module or submodule */
-    if ((c_ext->parent_stmt != LY_STMT_MODULE) && (c_ext->parent_stmt != LY_STMT_SUBMODULE)) {
-        lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
-                "Extension %s is allowed only at the top level of a YANG module or submodule, but it is placed in \"%s\" statement.",
-                p_ext->name, ly_stmt2str(c_ext->parent_stmt));
-        return LY_EVALID;
-    }
-    /* check mandatory argument */
-    if (!c_ext->argument) {
-        lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
-                "Extension %s is instantiated without mandatory argument representing metadata name.", p_ext->name);
-        return LY_EVALID;
-    }
-
-    mod_c = (struct lysc_module *)c_ext->parent;
-
-    /* check for duplication */
-    LY_ARRAY_FOR(mod_c->exts, u) {
-        if ((&mod_c->exts[u] != c_ext) && (mod_c->exts[u].def == c_ext->def) && !strcmp(mod_c->exts[u].argument, c_ext->argument)) {
-            /* duplication of the same annotation extension in a single module */
-            lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx), "Extension %s is instantiated multiple times.", p_ext->name);
-            return LY_EVALID;
-        }
-    }
+    struct lysc_ext_metadata *ann_cdata;
 
     /* compile annotation substatements */
-    c_ext->data = annotation = calloc(1, sizeof *annotation);
-    if (!annotation) {
+    ext->compiled = ann_cdata = calloc(1, sizeof *ann_cdata);
+    if (!ann_cdata) {
         goto emem;
     }
-    LY_ARRAY_CREATE_GOTO(lysc_ctx_get_ctx(cctx), c_ext->substmts, 6, ret, emem);
+    LY_ARRAY_CREATE_GOTO(lysc_ctx_get_ctx(cctx), ext->substmts, 6, ret, emem);
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_IFF].stmt = LY_STMT_IF_FEATURE;
-    c_ext->substmts[ANNOTATION_SUBSTMT_IFF].storage = &annotation->iffeatures;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[0].stmt = LY_STMT_IF_FEATURE;
+    ext->substmts[0].storage = NULL;
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_UNITS].stmt = LY_STMT_UNITS;
-    c_ext->substmts[ANNOTATION_SUBSTMT_UNITS].storage = &annotation->units;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[1].stmt = LY_STMT_UNITS;
+    ext->substmts[1].storage = &ann_cdata->units;
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_STATUS].stmt = LY_STMT_STATUS;
-    c_ext->substmts[ANNOTATION_SUBSTMT_STATUS].storage = &annotation->flags;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[2].stmt = LY_STMT_STATUS;
+    ext->substmts[2].storage = &ann_cdata->flags;
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_TYPE].stmt = LY_STMT_TYPE;
-    c_ext->substmts[ANNOTATION_SUBSTMT_TYPE].storage = &annotation->type;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[3].stmt = LY_STMT_TYPE;
+    ext->substmts[3].storage = &ann_cdata->type;
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_DSC].stmt = LY_STMT_DESCRIPTION;
-    c_ext->substmts[ANNOTATION_SUBSTMT_DSC].storage = &annotation->dsc;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[4].stmt = LY_STMT_DESCRIPTION;
+    ext->substmts[4].storage = &ann_cdata->dsc;
 
-    LY_ARRAY_INCREMENT(c_ext->substmts);
-    c_ext->substmts[ANNOTATION_SUBSTMT_REF].stmt = LY_STMT_REFERENCE;
-    c_ext->substmts[ANNOTATION_SUBSTMT_REF].storage = &annotation->ref;
+    LY_ARRAY_INCREMENT(ext->substmts);
+    ext->substmts[5].stmt = LY_STMT_REFERENCE;
+    ext->substmts[5].storage = &ann_cdata->ref;
 
-    ret = lys_compile_extension_instance(cctx, p_ext, c_ext);
+    ret = lyplg_ext_compile_extension_instance(cctx, extp, ext);
     return ret;
 
 emem:
-    lyplg_ext_log(c_ext, LY_LLERR, LY_EMEM, lysc_ctx_get_path(cctx), "Memory allocation failed (%s()).", __func__);
+    lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EMEM, "Memory allocation failed (%s()).", __func__);
     return LY_EMEM;
 }
 
@@ -117,27 +175,43 @@
  * Implementation of ::lyplg_ext_schema_printer_clb set as ::lyext_plugin::sprinter
  */
 static LY_ERR
-annotation_schema_printer(struct lyspr_ctx *ctx, struct lysc_ext_instance *ext, ly_bool *flag)
+annotation_sprinter(struct lyspr_ctx *ctx, struct lysc_ext_instance *ext, ly_bool *flag)
 {
-    lysc_print_extension_instance(ctx, ext, flag);
+    lyplg_ext_print_extension_instance(ctx, ext, flag);
 
     return LY_SUCCESS;
 }
 
 /**
- * @brief Free annotation extension instances' data.
+ * @brief Free parsed annotation extension instance data.
  *
- * Implementation of ::lyplg_ext_free_clb callback set as ::lyext_plugin::free.
+ * Implementation of ::lyplg_ext_parse_free_clb callback set as ::lyext_plugin::pfree.
  */
 static void
-annotation_free(struct ly_ctx *ctx, struct lysc_ext_instance *ext)
+annotation_pfree(const struct ly_ctx *ctx, struct lysp_ext_instance *ext)
 {
     if (!ext->substmts) {
         return;
     }
 
-    lyplg_ext_instance_substatements_free(ctx, ext->substmts);
-    free(ext->data);
+    lyplg_ext_pfree_instance_substatements(ctx, ext->substmts);
+    free(ext->parsed);
+}
+
+/**
+ * @brief Free compiled annotation extension instance data.
+ *
+ * Implementation of ::lyplg_ext_compile_free_clb callback set as ::lyext_plugin::cfree.
+ */
+static void
+annotation_cfree(const struct ly_ctx *ctx, struct lysc_ext_instance *ext)
+{
+    if (!ext->substmts) {
+        return;
+    }
+
+    lyplg_ext_cfree_instance_substatements(ctx, ext->substmts);
+    free(ext->compiled);
 }
 
 /**
@@ -153,13 +227,15 @@
         .revision = "2016-08-05",
         .name = "annotation",
 
-        .plugin.id = "libyang 2 - metadata, version 1",
-        .plugin.compile = &annotation_compile,
-        .plugin.sprinter = &annotation_schema_printer,
-        .plugin.free = annotation_free,
+        .plugin.id = "ly2 metadata v1",
+        .plugin.parse = annotation_parse,
+        .plugin.compile = annotation_compile,
+        .plugin.sprinter = annotation_sprinter,
         .plugin.node = NULL,
         .plugin.snode = NULL,
-        .plugin.validate = NULL
+        .plugin.validate = NULL,
+        .plugin.pfree = annotation_pfree,
+        .plugin.cfree = annotation_cfree,
     },
     {0}     /* terminating zeroed record */
 };