Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Welcome to Software Development on Codidact!

Will you help us build our independent community of developers helping developers? We're small and trying to grow. We welcome questions about all aspects of software development, from design to code to QA and more. Got questions? Got answers? Got code you'd like someone to review? Please join us.

Post History

75%
+4 −0
Q&A What might happen if I ignore warning?

Warnings most often mean "here is a bug which will likely cause your program to crash or misbehave". They do not mean "here's something that you can optionally fix when you can spare the time". See...

posted 3y ago by Lundin‭  ·  edited 3y ago by Lundin‭

Answer
#2: Post edited by user avatar Lundin‭ · 2021-08-31T10:12:41Z (over 3 years ago)
  • Warnings most often mean "here is a bug which will likely cause your program to crash or misbehave". They do _not_ mean "here's something that you can optionally fix when you can spare the time". See [What must a C compiler do when it finds an error?](https://software.codidact.com/posts/277340)
  • In your specific case, ignoring the warning leads to undefined behavior, meaning anything can happen. For example runaway code, crashes caused by stack corruption/wrong calling convention, wrong results calculated on garbage values, code getting incorrectly optimized and parts of it removed etc etc. [What is undefined behavior and how does it work?](https://software.codidact.com/posts/277486)
  • Warnings most often mean "here is a bug which will likely cause your program to crash or misbehave". They do _not_ mean "here's something that you can optionally fix when you can spare the time". See [What must a C compiler do when it finds an error?](https://software.codidact.com/posts/277340)
  • In your specific case, ignoring the warning leads to undefined behavior, meaning anything can happen. This is mentioned in the C standard C17 6.9.1/12:
  • > If the } that terminates a function is reached, and the value of the function call is used by the caller, the behavior is undefined.
  • For example runaway code, crashes caused by stack corruption/wrong calling convention, wrong results calculated on garbage values, code getting incorrectly optimized and parts of it removed etc etc. [What is undefined behavior and how does it work?](https://software.codidact.com/posts/277486)
#1: Initial revision by user avatar Lundin‭ · 2021-08-31T10:09:55Z (over 3 years ago)
Warnings most often mean "here is a bug which will likely cause your program to crash or misbehave". They do _not_ mean "here's something that you can optionally fix when you can spare the time". See [What must a C compiler do when it finds an error?](https://software.codidact.com/posts/277340)

In your specific case, ignoring the warning leads to undefined behavior, meaning anything can happen. For example runaway code, crashes caused by stack corruption/wrong calling convention, wrong results calculated on garbage values, code getting incorrectly optimized and parts of it removed etc etc. [What is undefined behavior and how does it work?](https://software.codidact.com/posts/277486)