17.6.2 ‘#line’ and TeX

As mentioned, makeinfo recognizes the ‘#line’ directives described in the previous section. However, texinfo.tex does not and cannot. Therefore, such a line will be incorrectly typeset verbatim if TeX sees it. The solution is to use makeinfo’s macro expansion options before running TeX. There are three approaches:

• If you run texi2dvi or its variants (see Format with texi2dvi), you can pass -E and texi2dvi will run makeinfo first to expand macros and eliminate ‘#line’.
• If you run makeinfo or its variants (see Generic Translator texi2any), you can specify --no-ifinfo --iftex -E somefile.out, and then give somefile.out to texi2dvi in a separate command.
• Or you can run makeinfo --dvi --Xopt -E. (Or --pdf instead of --dvi.) makeinfo will then call texi2dvi -E.

One last caveat regarding use with TeX: since the #line directives are not recognized, the line numbers emitted by the @errormsg{} command (see Conditional Commands), or by TeX itself, are the (incorrect) line numbers from the derived file which TeX is reading, rather than the preprocessor-specified line numbers. This is another example of why we recommend running makeinfo for the best diagnostics (see makeinfo Advantages).