libyang: create recipe for libyang

Add a new recipe, patches, and ptest coverage for libyang.

The recipe follows from upstream, using the cmake build system.

There were 2 small changes needed to get the package building:
  - Remove call to pcre2-config
  - Add missing import statement

The recipe has a dependency on libpcre2, which satisfies the minimum
requirements for libyang. In addition, for tests, cmocka is required
during build and runtime, and valgrind is required in the runtime for
some tests.

Due to the way the library by default builds in a debug mode, release
mode was specified. However, this disables building the built-in tests,
so an EXTRA_OECMAKE was added based on whether or not ptests are enabled
to specifiy the required extra flag.

Binconfig-disabled is inherited since using pcre2-config directly is not
suggested anymore. Cmocka as a dependency depends on whether ptests have
been enabled. Since ptests are built with the main package, we need
cmocka installed before the test are compiled if they are needed.

Ptest coverage:
The ptests come from the original tests included with the library.
Ptests are in ctest format by default, so we compare the return code to
print it in Yocto format. However, as each "test" target executable has
multiple tests in it, the full stdout and stderr logs are saved for
troubleshooting.

Currently, several of the tests fail due to hardcoded paths in the
executable binaries generated, this is an issue we will take upstream.
For now, only the tests which work on a different target are enabled as
the ptests. The list can be updated in the run-ptest script, which is
portable shell compatible, without requiring bash.

The recipe also has libyang-bin as a split package, which includes
yanglint should it be needed.
This recipe was tested using buildall-qemu as well as from within qemu
in x86_64 and arm64.

Signed-off-by: Tony Tascioglu <tony.tascioglu@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-extended/libyang/libyang/libyang-skip-pcre2-config-add-stdint-h.patch

@@ -0,0 +1,55 @@
+From c7f3e2a8fe530beec6103cb9071ccc41458879aa Mon Sep 17 00:00:00 2001
+From: Tony Tascioglu <tony.tascioglu@windriver.com>
+Date: Mon, 21 Jun 2021 12:34:22 -0400
+Subject: [PATCH] libyang: fix initial build errors
+
+This patch addresses build errors seen when integrating libyang as a
+recipe.
+
+The call to pcre2-config has been commented out. *-config calls are
+being replaced by pkgconfig, and we want to avoid the binary config
+calls. This call can safely be discarded since it is used to check
+the version of libpcre2 on the system, and all recent YP builds meet
+the minimum required version (v10.21).
+
+There is a missing include statement for stdint.h in utests.h which
+causes build problems. stdint.h is required to be imported by cmocka.h
+prior to the cmocka file. Adding the stdint allows it to build the
+tests correctly
+
+Upstream-Status: Pending
+
+Signed-off-by: Tony Tascioglu <tony.tascioglu@windriver.com>
+---
+ CMakeModules/FindPCRE2.cmake | 2 +-
+ tests/utests/utests.h        | 1 +
+ 2 files changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/CMakeModules/FindPCRE2.cmake b/CMakeModules/FindPCRE2.cmake
+index 8f60daa2..ad014f14 100644
+--- a/CMakeModules/FindPCRE2.cmake
++++ b/CMakeModules/FindPCRE2.cmake
+@@ -12,7 +12,7 @@ FIND_PATH(PCRE2_INCLUDE_DIR pcre2.h)
+ FIND_LIBRARY(PCRE2_LIBRARY NAMES libpcre2.a pcre2-8)
+ 
+ # Check required version
+-execute_process(COMMAND pcre2-config --version OUTPUT_VARIABLE PCRE2_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
++# execute_process(COMMAND pcre2-config --version OUTPUT_VARIABLE PCRE2_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
+ 
+ # Handle the QUIETLY and REQUIRED arguments and set PCRE_FOUND to TRUE if all listed variables are TRUE.
+ INCLUDE(FindPackageHandleStandardArgs)
+diff --git a/tests/utests/utests.h b/tests/utests/utests.h
+index 5bea0459..a256120c 100644
+--- a/tests/utests/utests.h
++++ b/tests/utests/utests.h
+@@ -23,6 +23,7 @@
+ #include <stddef.h>
+ #include <stdlib.h>
+ 
++#include <stdint.h>
+ #include <cmocka.h>
+ 
+ #include <string.h>
+-- 
+2.32.0
+

meta-oe/recipes-extended/libyang/libyang/run-ptest

@@ -0,0 +1,46 @@
+#!/bin/sh
+# Valid tests to run
+tests="utest_binary \
+       utest_bits \
+       utest_common \
+       utest_hash_table \
+       utest_inet_types \
+       utest_int8 \
+       utest_json \
+       utest_list \
+       utest_merge \
+       utest_metadata \
+       utest_parser_yang \
+       utest_parser_yin \
+       utest_pattern \
+       utest_printer_yang \
+       utest_printer_yin \
+       utest_range \
+       utest_schema \
+       utest_set \
+       utest_string \
+       utest_tree_data \
+       utest_tree_schema_compile \
+       utest_types \
+       utest_xml \
+       utest_xpath \
+       utest_yang_types \
+       utest_yanglib"
+
+# cd into right directory
+ptestdir=$(dirname "$(readlink -f "$0")")
+cd "$ptestdir"/tests || exit
+
+# Run specified tests
+for f in $tests
+do
+    if test -e ./"$f"; then
+        if ./"$f" > ./"$f".out 2> ./"$f".err; then
+            echo "PASS: $f"
+        else
+            echo "FAIL: $f"
+        fi
+    else
+        echo "SKIP: $f"
+    fi
+done

meta-oe/recipes-extended/libyang/libyang_2.0.7.bb

@@ -0,0 +1,37 @@
+SUMMARY = "YANG data modeling language library"
+DESCRIPTION = "libyang is a YANG data modelling language parser and toolkit written (and providing API) in C."
+HOMEPAGE = "https://github.com/CESNET/libyang"
+SECTION = "libs"
+LICENSE = "BSD-3-Clause"
+
+LIC_FILES_CHKSUM = "file://LICENSE;md5=f3916d7d8d42a6508d0ea418cfff10ad"
+
+SRCREV = "69d9fff65abb58beb0bb6aa9ecacd572ca1dfc56"
+
+SRC_URI = "git://github.com/CESNET/libyang.git \
+           file://libyang-skip-pcre2-config-add-stdint-h.patch \
+           file://run-ptest \
+           "
+
+S = "${WORKDIR}/git"
+
+COMPATIBLE_HOST_riscv32 = "null"
+COMPATIBLE_HOST_armv5 = "null"
+COMPATIBLE_HOST_riscv64 = "null"
+
+# Main dependencies
+inherit cmake pkgconfig lib_package binconfig-disabled ptest
+DEPENDS = "libpcre2"
+DEPENDS += "${@bb.utils.contains('PTEST_ENABLED', '1', 'cmocka', '', d)}"
+BINCONFIG = "${bindir}/pcre2-config"
+
+# Ptest dependencies
+RDEPENDS_${PN}-ptest += "valgrind"
+
+EXTRA_OECMAKE = "-DCMAKE_BUILD_TYPE=Release"
+EXTRA_OECMAKE += " ${@bb.utils.contains('PTEST_ENABLED', '1', '-DENABLE_BUILD_TESTS=ON', '', d)}"
+
+do_install_ptest () {
+    cp -fR ${B}/tests/ ${D}${PTEST_PATH}/
+}
+