plplot-devel

[Plplot-devel] plstrm.h and PLINTs

[Andrew R. <ar...@ge...>]

While trying to track down the problem with X20C and DJGPP I noticed that
there were several warnings for incompatible pointers being passed. Not a
real issue, it was just PLINT being passed to int and vice versa. Since
PLINT and int are usually the same it should not have made a real
difference to my problem, but it does present an ascetic situation for
compiling without warnings.

One thing I did find was that most of the new plimage commands expect
*dev_ix and *dev_iy in the PLStream structure to be defined as PLINT while
the PLStream structure defines them as type int. I know that is a simple
fix, but this is not really the reason I am writing the email. There are
many other variables of type "int" in PLStream, while the vast majority are
of type "PLINT". Is there any particular reason for this ? 

Should we consider coding all variables of type "int" to "PLINT" for
consistency as was done with "float" to "PLFLOAT" months ago ? 

I can't see any harm in it, but perhaps other people might have objections
or reasons for keeping some variables as "int" and others as "PLINT".
Changing them will also probably mean making the changes in the functions
that manipulate these variables to get rid of warnings as well of course.

- Andrew

Re: [Plplot-devel] plstrm.h and PLINTs

[Maurice L. <mj...@ga...>]

Andrew Roach writes:
 > While trying to track down the problem with X20C and DJGPP I noticed that
 > there were several warnings for incompatible pointers being passed. Not a
 > real issue, it was just PLINT being passed to int and vice versa. Since
 > PLINT and int are usually the same it should not have made a real
 > difference to my problem, but it does present an ascetic situation for
 > compiling without warnings.
 > 
 > One thing I did find was that most of the new plimage commands expect
 > *dev_ix and *dev_iy in the PLStream structure to be defined as PLINT while
 > the PLStream structure defines them as type int. I know that is a simple
 > fix, but this is not really the reason I am writing the email. There are
 > many other variables of type "int" in PLStream, while the vast majority are
 > of type "PLINT". Is there any particular reason for this ? 

Any pointer should be a (PLINT *), without fail, else bad things can happen.
But for vanilla integers it doesn't matter so much.  For local temporary
variables I think it's preferable to just use int or long as appropriate.
The only negative is if you assign a PLINT to an int you might get compiler
warnings about possible overflow.

-- 
Maurice LeBrun    mj...@ga...