) in comment breaks function prototype generation

[FRautenberg]

Describe the problem

In order to make it easier for beginners to get started with writing Arduino sketches, and for the convenience of all users, Arduino CLI automatically generates and adds prototypes for functions defined in a .ino file of a sketch.

🐛 If a closing bracket is commented out within parameters, no prototype is generated for the function.

To reproduce

Compile this sketch:

void setup() {
  foo(1,2);
}
void loop() {}
void foo(int a,  // )
         int b) {}

🐛 Compilation fails spuriously:

C:\Users\per\AppData\Local\Temp\arduino_modified_sketch_281391\sketch_apr03a.ino: In function 'void setup()':
sketch_apr03a:2:3: error: 'foo' was not declared in this scope
   foo(1,2);
   ^~~

Arduino CLI version

Original report

a4ee670a

Last verified with

c5812eea68afdb0e4e774f4f15ec4a34f0c3100c

Operating system

• Windows

Operating system version

• Windows 10
• Windows 11

Additional context

If the ) is removed from the comment the prototype generation works correctly:

void setup() {
  foo(1,2);
}
void loop() {}
void foo(int a,  //
         int b) {}

Workaround

Add a prototype for the function in the sketch before the first reference:

void foo(int a, int b);
void setup() {
  foo(1,2);
}
void loop() {}
void foo(int a,  // )
         int b) {}

Issue checklist

• [X] I searched for previous reports in the issue tracker
• [X] I verified the problem still occurs when using the nightly build
• [X] My report contains all necessary details

[per1234]

The bug does occur in the hourly build, but not in the beta build of the Arduino IDE, so arduino-preprocessor handles this code correctly.

I'll leave it to the developers to decide whether to consider this bug fixed already.

[ubidefeo]

please @cmaglie see if this is resolved or not

[per1234]

@ubidefeo it's not resolved. I verified it with the latest nightly Arduino CLI before transferring it here from the arduino/Arduino repository.

[ubidefeo]

@per1234 I have assigned it to @cmaglie based on your previous comment

I'll leave it to the developers to decide whether to consider this bug fixed already.

[umbynos]

This seems to be a problem of the preprocessor (ctags) fixing it upstream is basically impossible, an alternative would be to switch to arduino-prepocessor but needs some love (still uses an old version of llvm). I don't see it coming shortly.