How to write C++ program and turn it into ipk package

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Create a cpp-demo directory under the SDK/package/ path and generate a very simple cpp program

$cd SDK$ mkdir-p package/cpp-demo$ cd package/cpp-demo$ touch Makefile$ mkdir src$ cd src$ touch Makefile main.cpp

Form the following directory structure:

$tree package/demo-cpppackage/cpp-demo/ |-- Makefile`-- src |-- main.cpp `--Makefile

Package/cpp-demo/src/main.cpp content:

# include using namespace std;int main (int argc, char * * argv) {cout

Delete the SDK/build_dir and re-make. In order to facilitate analysis

$rm-rf build_dir$ make VIPs | less

Analyze the printed information:

CC= "mips-openwrt-linux-uclibc-gcc" GCC= "mips-openwrt-linux-uclibc-gcc" CXX= "mips-openwrt-linux-uclibc-g++"... make [4]: Entering directory `/ home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/build_dir/target-mips_34kc_uClibc-0.9.33.2/cpp-demo'make [4]: Nothing to be done for `ALL'.make [4]: Leaving directory` / home/hevake_lcj/Workspace/OpenWRT/OpenWrt- SDK/build_dir/target-mips_34kc_uClibc-0.9.33.2/cpp-demo'...

Huh? Nothing to be done for 'ALL', indicates that there is nothing more to compile.

I hastened to check

[SDK] $ls build_dir/target-mips_34kc_uClibc-0.9.33.2/cpp-demo/cpp-demo ipkg-ar71xx main.cpp main.o Makefile

It is found that cpp-demo has been generated and can be run on the development machine. How did this cpp-demo come from? Can you tell if it comes from package/cpp-demo/src?

It suddenly occurred to me that I had entered the package/cpp-demo/src/ path and executed make once, and I must have generated a cpp-demo executable program at that time. View it:

[SDK] $ls package/cpp-demo/src/cpp-demo main.cpp main.o Makefile

There is it! In make, because of its existence, the compiler component thinks that it is no longer necessary to compile, which leads to the above problems.

Delete cpp-demo and main.o. Go back to SDK and re-make

$rm-rf build_dir$ make VIPs | less

Analyze the printed information:

CC= "mips-openwrt-linux-uclibc-gcc" GCC= "mips-openwrt-linux-uclibc-gcc" CXX= "mips-openwrt-linux-uclibc-g++"... make [4]: Entering directory `/ home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/build_dir/target-mips_34kc_uClibc-0.9.33.2/cpp-demo'mips-openwrt-linux-uclibc-g++-Os-pipe-mno-branch-likely-mips32r2-mtune=34kc-fno-caller-saves-fhonour-copts- Wno-error=unused-but-set-variable\-msoft-float-mips16-minterlink-mips16-I/home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/staging_dir/target-mips_34kc_uClibc-0.9.33.2/usr/include\-I/home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/staging_dir/target-mips_34kc_uClibc-0.9.33.2/include\-I/home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK / staging_dir/toolchain-mips_34kc_gcc-4.8-linaro_uClibc-0.9.33.2/usr/include\-I/home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/staging_dir/toolchain-mips_34kc_gcc-4.8-linaro_uClibc-0.9.33.2/include\-c-o main.o main.cppecho "DEBUG: CXX = mips-openwrt-linux-uclibc-g++" DEBUG: CXX = mips-openwrt-linux-uclibc-g++mips -openwrt-linux-uclibc-g++-o cpp-demo main.omake [4]: Leaving directory `/ home/hevake_lcj/Workspace/OpenWRT/OpenWrt-SDK/build_dir/target-mips_34kc_uClibc-0.9.33.2/cpp-demo'...

According to the debugging information, you can know that cpp-demo is compiled with mips-openwrt-linux-uclibs-g++. This should be right!

Try to transfer the ipk file to the target machine again and install it. The running effect is as follows:

Root@OpenWrt:~# cpp-demo This is C++ Demo

Succeed!

Thank you for your reading, the above is the content of "how to write the C++ program and make it into an ipk package". After the study of this article, I believe you have a deeper understanding of how to write the C++ program and make it into an ipk package, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!