C: what? "may be used uninitialized" but I have init it. (solved!)

[squadchannel]

SOLVED!

Code: [Select]

main.c|344|warning: 'term' may be used uninitialized [-Wmaybe-uninitialized]

Why is this happening even though I've init it?

It started happening when I added

Code: [Select]

term = 2;
if(term == 2) goto err0;

if -O3 and -s options aren't specified, it compiles normally. no errors.
"term" is not referenced anywhere other than in the highlighted section.
I'm getting a warning, but it's working fine.
hmmm....?

[negativ3]

Code: [Select]

if (term == 2) {
    goto err0;
}

[squadchannel]

is valid syntax even when written on a single line.

[Andy Watson]

It is saying that there is some path whereby you can arrive at "err1" (line 343) without term being initialised.
More pedantically, the compiler is warning that there may be a path to line 343 that does not include initialising term. As far as I can see, the snippet of code that you shown does not give the source of the "goto err1:" , it appears to be outside the scope of the "int term = 0;"(line 171).

[negativ3]

term == 2;
This line does nothing (it's a no-op). It compares term with 2, but throws away the result.

[squadchannel]

It is saying that there is some path whereby you can arrive at "err1" (line 343) without term being initialised.
More pedantically, the compiler is warning that there may be a path to line 343 that does not include initialising term. As far as I can see, the snippet of code that you shown does not give the source of the "goto err1:" , it appears to be outside the scope of the "int term = 0;"(line 171).

Yeah, you're right. Now that I think about it, absolutely right.
optimization are doing a better job than I expected.

term == 2;
This line does nothing (it's a no-op). It compares term with 2, but throws away the result.

What do you mean? valid syntax in GCC.

[negativ3]

It is saying that there is some path whereby you can arrive at "err1" (line 343) without term being initialised.
More pedantically, the compiler is warning that there may be a path to line 343 that does not include initialising term. As far as I can see, the snippet of code that you shown does not give the source of the "goto err1:" , it appears to be outside the scope of the "int term = 0;"(line 171).

Yeah, you're right. Now that I think about it, absolutely right.
optimization are doing a better job than I expected.

term == 2;
This line does nothing (it's a no-op). It compares term with 2, but throws away the result.

What do you mean? valid syntax in GCC.

It's like asking your friend "Do you want ice cream?" and then never giving them any or doing anything about it.

[squadchannel]

I resolved the issue by moving term above err1.

When I have to terminate the program due to an error midway through, I wonder how I should free the declarated handles up to that point...
I could use a goto and jump to the end, but that would make it impossible to use VLAs, so it’s a bit of a dilemma.
grouping the handles into a struct might be a good approach.

[JPortici]

What do you mean?

what do you think "term == 2;" does?

[squadchannel]

evaluate the expression. do nothing.


Oh, maybe you mean this?
It's a typo.

It started happening when I added

Code: [Select]

term == 2;
if(term == 2) goto err0;


[gf]

Are there any goto err1, err2 or err3 before line 171 ?

[squadchannel]

Yes, that exists, and I resolved it by moving the term declaration before err1.

[TheCalligrapher]

It's a typo.

"Typo" where? In this forum? Or in the actual code?

And why is it no longer present in the post? Did you actually edit the original post???

[squadchannel]

Yes, I made the edits and mentioned the changes.
I’ve resolved the issue, so you don’t need to waste any more of your time on this.

[Siwastaja]

Yes, I made the edits and mentioned the changes.
I’ve resolved the issue, so you don’t need to waste any more of your time on this.

If I may suggest for the future:

1) Reduce the code to minimum what demonstrates the problem. Usually you find the problem yourself while doing this,
2) Then post the whole code
(1 and 2 are important combined - if you don't reduce to minimum, posting it all is too much. But not posting it all leads to the problem being outside of what you posted, hence useless.)
3) Post it as text, e.g. using the code tag, not as screen capture
4) Feel free to edit to fix typos in your message, not the code. By all means edit to add ancillary information - but the code is important as-is.