使用 VC++ 编译生成的 C++ 代码

Question

I need to write a program that generate c++ code, compile it, and run it, so I finished the code generation part, and wrote it to a file called GeneratedCode.cpp. Now I'm stuck at the compile part, I wrote:

system(R"(call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat")");
system(R"(call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\vcvars32.bat")");
system("cl GeneratedCode.cpp");

First of all, is this the right way to do this? Info about this subject is quite scarce, especially for VC++. If it is, then I have problems both when using an IDE or not.

When using an IDE it gives me: "GeneratedCode.cpp(2): fatal error C1034: iostream: no include path set". I'm using iostream header of course.

When running the exe directly, it gives me: " 'cl' is not recognized as an internal or external command, operable program or batch file". Even though I called vcvarsall.bat and vcvars32.bat.

Answer 1

Each call to system or _wsystem creates a new environment which is lost when the call terminates. If your program requires environment variables to be set up like the Visual C++ Command Prompt's LIB , INCLUDE , etc. then you aren't going to succeed by calling system multiple times.

Here are your options, in the order that I would recommend them:

1. Eschew system all together. Set up the required environment block for cl.exe to work properly with string concatenation functions, as demonstrated here , and call CreateProcess with that environment.
2. Have your program write a batch file that contains all the prerequisite commands for cl.exe to work properly, call system on that, then delete the batch file.
3. Chain the commands together with && and call system once with a big string of multiple commands.