# Porting a Library Built Using Makefile
- [Source Code Acquisition](#section114115321416)
- [Cross-Compilation Settings](#section81263255384)
- [Library Test](#section1830015913391)
- [Adding the Compiled yxml Library to the OpenHarmony Project](#section1898016213406)
The following shows how to port the yxml library.
## Source Code Acquisition
Acquire the source code of yxml from [the open-source repository](https://github.com/getdnsapi/yxml). The following table lists the directory structure.
**Table 1** Directory structure of the source code
Directory
Description
yxml/bench/
Benchmark-related code
yxml/test/
Input and output files as well as scripts of the test cases
yxml/Makefile
File for organizing compilation
yxml/.gitattributes
-
yxml/.gitignore
-
yxml/COPYING
-
yxml/yxml.c
-
yxml/yxml.c.in
-
yxml/yxml-gen.pl
-
yxml/yxml.h
-
yxml/yxml.md
-
yxml/yxml-states
-
## 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 \(listed in [Table 1](#table16520154171813)\) 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_SYSROOT_PATH)
```
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 \(listed in [Table 1](#table16520154171813)\) 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. For OpenHarmony, set **OHOS\_SYSROOT\_PATH** to the absolute path of the **out/hispark\__xxx_/ipcamera\_hispark\__xxx_/sysroot** directory. This directory is generated after full compilation is complete. Therefore, complete full compilation before porting.
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 the procedure described in [Porting a Library Built Using CMake](porting-thirdparty-cmake.md#section6686144293611). The following describes how to use the test cases of the yxml library.
**Table 3** Directory structure of the test directory
Automatic test script, which cannot be used because OpenHarmony does not support automatic script execution. However, you can refer to this script to conduct a manual test.
openHarmony/third_party/yxml/yxml/out/test/test
Executable file for testing.
openHarmony/third_party/yxml/yxml/out/test/*.xml
Input test file.
openHarmony/third_party/yxml/yxml/out/test/*.out
Expected output file.
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](#table115941423164318) directory as an example, copy the following content to shell and press **Enter**:
```
```
3. Check whether the output in the shell is the same as that of the **_\*_.out** file in the [test](#table115941423164318) 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](#table115941423164318) 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 the procedure described in [Porting a Library Built Using CMake](porting-thirdparty-cmake.md#section1651053153715).
- 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
Directory
Description
openHarmony/third_party/yxml/BUILD.gn
GN file for adding the third-party library to the OpenHarmony project
openHarmony/third_party/yxml/build_thirdparty.py
Script file for GN to call the shell command to convert compilation from GN to Makefile.
openHarmony/third_party/yxml/config.gni
Third-party library compilation configuration file, which can be modified to determine whether the test cases will be used during the building