Cling does not report failed compilation (on MacOS)

[vepadulano]

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Description

Cling does not provide a way to programmatically check for a compilation failure, see the reproducer. I tried ProcessLine, Calc and Evaluate but no API works. Run the reproducer below with any of the three functions I see the assertion being triggered.

Expected behaviour

There should be a way to query the interpreter to know whether the last compilation was successful or failed.

Reproducer

#include <TInterpreter.h>
#include <cassert>

void processline(){
    TInterpreter::EErrorCode error = TInterpreter::kNoError;
    gInterpreter->ProcessLine("rndm_stuff", &error);
    assert(error != TInterpreter::kNoError);
}

void calc(){
    TInterpreter::EErrorCode error = TInterpreter::kNoError;
    gInterpreter->Calc("rndm_stuff", &error);
    assert(error != TInterpreter::kNoError);
}

void evaluate(){
    std::unique_ptr<TInterpreterValue> v = gInterpreter->MakeInterpreterValue();
    auto ret = gInterpreter->Evaluate("rndm_stuff", *v);
    assert(ret == 0);
}

int main(){
    processline();
    calc();
    evaluate();
}

ROOT version

master

Installation method

Build from source

Operating system

MacOS

Additional context

No response

[ferdymercury]

Are you compiling the reproducer in debug mode? Otherwise assert is skipped. Or switch to throw?

[vepadulano]

Hi @ferdymercury , thanks for the reply! Yes, the example requires compilation such that NDEBUG is not defined. Although that's besides the point, the same would happen with an if condition.

[ferdymercury]

the same would happen with an if condition.

Not really, at least not on Ubuntu 22 with master debug build. See below modified reproducer:

which returns to me:

ProcessLine detected failure: 1
Calc detected failure: 1
Evaluate detected failure:  Error evaluating expression (rndm_stuff)

#include <TInterpreter.h>
#include <iostream>

void processline(){
    TInterpreter::EErrorCode error = TInterpreter::kNoError;
    gInterpreter->ProcessLine("rndm_stuff", &error);
    if (error != TInterpreter::kNoError) std::cerr << "ProcessLine detected failure: " << error << std::endl;
}

void calc(){
    TInterpreter::EErrorCode error = TInterpreter::kNoError;
    gInterpreter->Calc("rndm_stuff", &error);
    if (error != TInterpreter::kNoError) std::cerr << "Calc detected failure: " << error << std::endl;
}

void evaluate(){
    std::unique_ptr<TInterpreterValue> v = gInterpreter->MakeInterpreterValue();
    try {
        auto ret = gInterpreter->Evaluate("rndm_stuff", *v);
        std::cout << ret << std::endl;
    } catch (std::runtime_error &e) {
        std::cerr << "Evaluate detected failure: " << " " << e.what() << std::endl;
    }
}

int main(){
    processline();
    calc();
    evaluate();
}

[ferdymercury]

I see the assertion being triggered.

Or did you rather want to write

assert(error == TInterpreter::kNoError);

instead of

assert(error != TInterpreter::kNoError); ?

[vepadulano]

I copy-pasted your example, and I confirm the issue:

$ ./cling_repro_if.out
input_line_9:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
input_line_11:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
input_line_13:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
1

Not really, at least not on Ubuntu 22

Since you wrote this, it can be that this issue only appears on MacOS

[ferdymercury]

it can be that this issue only appears on MacOS

Ahh right.

So maybe it's related to / dupe of #7541 by @hahnjo

On Ubuntu, the code throws Cling::CompilationExceptions or errors, see full output below, so maybe MacOs is not catching them properly?

input_line_9:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
Error in <HandleInterpreterException>: Error evaluating expression (rndm_stuff)
Execution of your code was aborted.
ProcessLine detected failure: 1
input_line_11:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
Error in <TInterpreter::Calc>: Error evaluating expression (rndm_stuff).
Evaluation of your expression was aborted.
Calc detected failure: 1
input_line_13:2:3: error: use of undeclared identifier 'rndm_stuff'
 (rndm_stuff)
  ^
Evaluate detected failure:  Error evaluating expression (rndm_stuff)

[vepadulano]

It should not rely on exceptions in the first place, that's why all interpreter APIs have error codes whether as input arguments or return values.