Re: strange byte compiler behavior

[Dan Nicolaescu <dann@ics.uci.edu>]

Dan Nicolaescu <dann@ics.uci.edu> writes:

  > When compiling vc-cvs in batch mode (cd emacs/lisp; make recompile) 
  > no warning is issued. 
  > 
  > When compiling it with M-x byte-compile-file this warning is issued:
  > 
  > In vc-cvs-register:
  > vc-cvs.el:301:41:Warning: reference to free variable `file'
  > 
  > 
  > The warning is correct, it looks like vc-cvs-register has a bug, it
  > should look at `files', not `file'.
  > 
  > Any idea why this warning is not issued in batch mode?


Investigating a bit: 

1. 
cd lisp ; make recompile 

which runs: -batch --no-site-file --multibyte --eval "(batch-byte-recompile-directory 0)"
does NOT warn

but running: 

-batch --no-site-file --multibyte --eval '(byte-compile-file "vc-cvs.el")'

warns

2. the warning is related to the name `file', if the variable is renamed
`file1' both the batch mode and interactive mode produce a warning.

3. Adding this:

   (message "var %s boundp %s" var  (boundp var))
to `byte-compile-variable-ref' shows that `file' is bound for the function
in question.  Which would explain the results. 
Any idea what causes `file' to be bound? (Assuming that boundp is the
correct test in that context...)