[clang-repl] Inconsitent flushing between out of process and in-process mode

[anutosh491]

I’m using an x86_64-unknown-linux-gnu machine

// out of process
anutosh491@vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl   --oop-executor=$PWD/llvm-jitlink-executor
clang version 22.0.0git (https://github.com/anutosh491/llvm-project.git 81ad8fbc2bb09bae61ed59316468011e4a42cf47)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /build/anutosh491/llvm-project/build/bin
Build config: +unoptimized, +assertions
clang-repl> #include <iostream>
clang-repl> std::string myname;
clang-repl> std::cin >> myname;
Anutosh
clang-repl> std::cout << "Your name is " << myname;
clang-repl> 

// in process
anutosh491@vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl
clang-repl> #include <iostream>
clang-repl> std::string myname;
clang-repl> std::cin >> myname;
Anutosh
clang-repl> clang-repl> std::cout << "Your name is " << myname << std::endl;
Your name is Anutosh
clang-repl> 

[anutosh491]

Ahh flushing makes it work though !

anutosh491@vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl   --oop-executor=$PWD/llvm-jitlink-executor
clang version 22.0.0git (https://github.com/anutosh491/llvm-project.git 81ad8fbc2bb09bae61ed59316468011e4a42cf47)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /build/anutosh491/llvm-project/build/bin
Build config: +unoptimized, +assertions
clang-repl> #include <iostream>
clang-repl> std::string name;
clang-repl> std::cin >> name;
Anutosh
clang-repl> std::cout << name << std::endl;
Anutosh

But I'm guessing the above segment still needs a fix ?

[anutosh491]

I realize this is not stdin specific. It's more likely inconsistency between flushing for in process and out of process.

// out of process
anutosh491@vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl   --oop-executor=$PWD/llvm-jitlink-executor
clang version 22.0.0git (https://github.com/anutosh491/llvm-project.git 81ad8fbc2bb09bae61ed59316468011e4a42cf47)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /build/anutosh491/llvm-project/build/bin
Build config: +unoptimized, +assertions
clang-repl> #include <iostream>
clang-repl> std::cout << "hello";
clang-repl> std::cout << "hello" << std::endl;
hellohello

// in process
anutosh491@vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl
clang-repl> #include <iostream>
clang-repl> std::cout << "hello";
helloclang-repl> std::cout << "hello" << std::endl;
hello

Not sure which behaviour is the intended behaviour here ( @vgvassilev could educate us) but I am guessing we need to stick to one for both of these ?

[anutosh491]

but I am guessing we need to stick to one for both of these ?

I think its important to introduce consistency here isn't it ? Cause if the repl behaviour is inconsistent then we would notice it at places we put the repl to use and then we would have to introduce fixes (based on the mode, in-process or out of process) at the library level (cppinterop) or the kernel level (xeus-cpp). Fixes catering to individual modes here would just mean more maintainance right !

Rather if we handle any incosistency at the repl level itself, the levels above wouldn't be concerned.

If someone educates me on what's the inteded behaviour, I would work towards fixing the other.

[vgvassilev]

We probably need to flush after each input line…