Syntax for ignoring Code Analyzer warning "This statement cannot be reached"

I'm aware of a few warning ignore comment syntaxes, such as

%#ok<AGROW>

for variables that change size on each loop iteration. But I haven't been able to find one for if branch errors, such as in

flag = 0;
if flag
    foo
end

In fact, it's been stated elsewhere that no central list of warning IDs exists, which frankly is inexcusable. Where is a list of common warning IDs and their ignore comments?

[Alejandro Arrizabalaga]

I used to suffer a lot from this issue. The solution is very simple but also weird, which is just to do:

flag = 0;
if flag ~= 0
    foo
end

I would have expected MATLAB to check flag to be true (1) or false (0) without having to explicitly write flag ~= 0. But it seems that MATLAB Code Analyzer complains if one does not do this.

Answer 1

[Jan]

Simply press the right mouse key on the line, which is marked in the editor. Then "supressing on this line" inserts (at least in R2018b):

 %#ok<UNRCH> 

I find a list at:

 C:\Program Files\MATLAB\R2018b\help\matlab\matlab_mlint_csh\matlab_mlint_csh.map
 %                       ^^^^^^  adjust this
 
 
mlint_nospc the-file-file-is-too-large-or-complex-to-analyze-nospc.html
mlint_mbig this-file-is-too-big-for-code-analyzer-to-handle-mbig.html
mlint_badot use-of-two-dots-is-an-invalid-matlab-construction-badot.html
mlint_mdeep parentheses-brackets-and-braces-are-nested-too-deeply-mdeep.html
mlint_deepc block-comments-are-nested-too-deeply-deepc.html
mlint_deepn functions-are-nested-too-deeply-deepn.html
...
mlint_unrch this-statement-and-possibly-following-ones-cannot-be-reached-unrch.html
...

You can produce the list dynamically also: Open Matlab's preferences -> Code Analyser -> select one entry -> Ctrl-A -> "Disable all" -> Save as file with a new file name -> Restore the former settings.

Now open the file in the prefdir folder:

# Copyright 2021 The MathWorks, Inc.

0ADAPPREF
0ADMTHDINV
0ADPROP
0ADPROPLC
0ADTPATH
0AFADJLMS
...

[Jack Gallagher]

as simple as a right-click! Thank you for the useful yet comprehensive answer.