preprocessor/5899: -M disables -dM

[neil@gcc.gnu.org]

Synopsis: -M disables -dM

State-Changed-From-To: open->analyzed
State-Changed-By: neil
State-Changed-When: Sat Mar  9 11:40:58 2002
State-Changed-Why:
    I'm not sure this behaviour is a good idea.  The documentation in 3.0 for -dM begins "Instead of the normal output", and the documentation for -M begins "Instead of outputting the result of preprocessing, output a rule suitable for make".  In other words, I think you're relying on undocumented behaviour that just happened to work.
    
    What did 2.95 do?  I believe it output both to the same place.  I'm waiting for confirmation from Chris Demetriou that the semantics of 3.1 now match 2.95 for -M etc., which is a regression that was fixed, and is pending for 3.0.5.  If the 3.0 behaviour is not a regression from 2.95 then I see no reason to preserve it, particularly if it was undocumented.
    
    Neil.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=5899