Completion of error handling

[elfring]

I have looked at a few source files for your current software. I have noticed that some checks for return codes are missing.

Would you like to add more error handling for return values from functions like the following?

• ftell ⇒ stbi_info_from_file
• fwrite ⇒ sixel_to_png
• malloc ⇒ sixel_create_image

[saitoha]

fwrite ⇒ sixel_to_png malloc ⇒ sixel_create_image

Thanks!! I corrected above items you pointed out by 2b8d931.

ftell ⇒ stbi_info_from_file

I keep it as is. So it seems to be dead code :)

[elfring]

I suggest to avoid ignorance of return values a bit more.

Are you interested to apply aspect-oriented software development? How do you think about to encapsulate error detection and corresponding exception handling as a reusable aspect in your software?

[elfring]

How do you think about to improve static source code analysis also for your software?

Do you find information sources like the following useful?

• Article "A Reusable Aspect for Memory Allocation Checking"
• Document "Aspect-Oriented Software Development - An Introduction" by Johan Brichau and Theo D'Hondt
• Paper "On Typesafe Aspect Implementations in C++" by Daniel Lohmann and Olaf Spinczyk

[elfring]

Would you like to reopen this bug report?

[saitoha]

I’d like to try such analysis tools to detect "ignorance of return values". Which is your recommendation among this list? https://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis#C.2FC.2B.2B

[elfring]

I suggest to reuse the following tools for finding more update candidates depending on your preferences for factors like freedom, licence costs and programming language support.

1. AspectC++
2. Secure Programming Lint
3. Coccinelle
4. Coverity Scan

[saitoha]

I think it's done in develop branch. Semantic error handling is available by introducing new API set that returns error code SIXELSTATUS. Thanks!

[elfring]

Did you try any static source code analysis out with your updated application programming interface?

How do you think about to annotate any functions with "__attribute__((warn_unused_result))"?