Target Language Compiler

Formatting Error Messages

You should be careful when formatting error message strings. For example, suppose you create a local variable (called message) that contains text that has new lines.

• %openfile message
  My message text
  with new lines (carriage returns)
  %closefile message
  

If you then want to create another variable and prefix this message with the text "RTW Error:", you need to use

• %openfile errorMessage
  RTW Error: %<message>
  %closefile errorMessage
  

or

• %assign errorMessage = "RTW Error:"+ message
  

The statement

• %assign errorMessage = "RTW Error: %<message>"
  

will cause a syntax error during TLC execution and your message will not be displayed. This should be avoided. Use the function LibBlockReportError to help prevent this type of runtime syntax error. The syntax error occurs because TLC evaluates the message, which causes new lines to appear in the assignment statement that appear as unterminated text strings (i.e., the trailing quote is missing).

After formatting your error message, use LibBlockReportError, a similar function, or %exit to report your error when it occurs.

Testing Error Messages

It is strongly suggested that you test your error messages before releasing your new TLC code. To test your error messages, copy the relevant code into a test.tlc file and run

• tlc test.tlc
  

at the MATLAB prompt.

Fatal (Internal) TLC Coding Errors

TLC Error Messages