Porting a Library Built Using Makefile

• Source Code Acquisition
• Cross-Compilation Settings
• Library Test
• Adding the Compiled yxml Library to the Project

The following shows how to port the yxml library.

Source Code Acquisition

Acquire the source code of yxml from https://github.com/getdnsapi/yxml. The following table lists the directory structure.

Table 1 Directory structure of the source code

Cross-Compilation Settings

The following steps show how to configure and modify the toolchains for cross-compiling the libraries built using CMake to compile executable files for the OpenHarmony platform.

1. Configure the toolchains.

   Replace the original configuration of MakeFile (listed in Table 1) in the root directory of the yxml library with the following clang toolchains configuration.

   clang toolchains configuration:

   # Set the cross-compilation toolchain and ensure that the path of the toolchain has been added to the PATH environment variable.
   CC:=clang
   AR:=llvm-ar
   # The --target and --sysroot flags must be specified.
   CFLAGS:=-Wall -Wextra -Wno-unused-parameter -O2 -g --target=arm-liteos -march=armv7-a --sysroot=$(OHOS_ROOT_PATH)prebuilts/lite/sysroot

   Original configuration:

   CC:=gcc
   AR:=ar
   CFLAGS:=-Wall -Wextra -Wno-unused-parameter -O2 -g

2. Perform the compilation.

   Run a Linux command to enter the directory (listed in Table 1) for storing yxml source files and then run the following command:

   make test OHOS_SYSROOT_PATH=...

   OHOS_SYSROOT_PATH specifies the absolute path of the directory where sysroot is located. Taking OpenHarmony for example, set OHOS_SYSROOT_PATH to the absolute path of prebuilts/lite/sysroot/.

3. View the result.

   After step 2 is complete, a static library file and test case are generated in the out directory of the yxml library.

   Table 2 Directory structure of compiled files

   Directory	Description
   openHarmony/third_party/yxml/yxml/out/lib/	Static library file
   openHarmony/third_party/yxml/yxml/out/test/	Test cases as well as the input and output files

Library Test

The test procedure for the yxml library is similar to that for the double-conversion library. For details, see Library Test. The following describes how to use the test cases of the yxml library.

Table 3 Directory structure of the test directory

The content of the test.sh file is as follows:

#!/bin/sh
for i in *.xml; do
  b=`basename $i .xml`
  o=${b}.out
  t=${b}.test
  ./test <$i >$t
  if [ -n "`diff -q $o $t`" ]; then
    echo "Test failed for $i:"
    diff -u $o $t
    exit 1
  fi
done
echo "All tests completed successfully."

The shell of OpenHarmony does not support input and output redirection symbols (< and >). During the test, you need to copy the content in the *.xml file to the shell and press Enter. The output content is displayed in the shell screen.

The following operations are performed based on the assumption that the OpenHarmony environment has been set up and the nfs directory has been mounted and accessed.

1. Execute the following command:

   ./test

2. Copy the content in the *.xml file to shell.

   Taking the pi01.xml file in the test directory as an example, copy the following content to shell and press Enter:

   <?SomePI abc?><a/>

3. Check whether the output in the shell is the same as that of the *.out file in the test directory.

   The output is as follows:

   pistart SomePI
   picontent abc
   piend
   elemstart a
   elemend
   ok

   The output is the same as the pi01.out file in the test directory. The test is passed.

Adding the Compiled yxml Library to the OpenHarmony Project

The procedure for adding the yxml library is almost the same as that for adding the double-conversion library, except that the implementation of build.gn and config.gni files. For details, see Adding the Compiled double-conversion Library to the OpenHarmony Project.

• The implementation of the newly added BUILD.gn file in the yxml library is as follows:

import("config.gni")
group("yxml") {
    if (ohos_build_thirdparty_migrated_from_fuchisa == true) {
        deps = [":make"]
    }
}
if (ohos_build_thirdparty_migrated_from_fuchisa == true) {
    action("make") {
        script = "//third_party/yxml/build_thirdparty.py"
        outputs = ["$target_out_dir/log_yxml.txt"]
        exec_path = rebase_path(rebase_path("./yxml", root_build_dir))
        command = "make clean && $MAKE_COMMAND"
        args = [
            "--path=$exec_path",
            "--command=${command}"
        ]
    }
}

• The configuration of the newly added config.gni file in the yxml library is as follows:

TEST_ENABLE = "YES"

if (TEST_ENABLE == "YES") {
    MAKE_COMMAND = "make test OHOS_SYSROOT_PATH=${ohos_root_path}prebuilts/lite/sysroot/"
} else {
    MAKE_COMMAND = "make OHOS_SYSROOT_PATH=${ohos_root_path}prebuilts/lite/sysroot/"
}

• The following table lists the directory structure of the OpenHarmony project.

Table 4 Directory structure of the ported library