Error 71: Out of ROM, A segment or the program is too large

[allenhuffman]

Revisiting this topic which has come up in this forum from time to time.

We have one PIC24 project that is too large when we enable our debugging/printf support. As a simple workaround, I use an #ifdef to omit the message handling code. This is how we've used it for years.

I now find myself in need of debugging the message handling code.

Per repeated advice in this forum, all our C files are #included, so I can easily change the order. This is a game of Whak-A-Mole(tm) without more understanding of how things fit into these segments.

I have also split up the large function where the error appears. Then it just moves to the second. Then the third.

After commenting out most of the debug prints, I get to a "almost" fit:

[Ttelmah]

Try using #separate on some of the subroutines. Also you could
try the compress option for #opt.
The latter though can make code much harder to debug.
The compiler tends to default to inlining small functions.

[jeremiah]

You can also see if your code already has any #org directives. They could be artificially limiting certain blocks of memory in size. If so maybe you could adjust those some.

[newguy]

printf is very likely being inlined for every instance; I speak from experience and have stared down the same issue in the past.

As Ttelmah has said, the compiler defaults to inline-ing printf statements. You can force it to reuse code by wrapping printf statements in your own my_printf(args) { printf(args) } functions. That will save a lot of ROM, but tedious.

[Jerson]

Adding to what ttelmah has written, you can split some long subroutines into sub-subroutines. That allows the compiler to place them in available segments rather than one long contiguous one. You may find solace in #separate and splitting code into smaller functions.

[Ttelmah]

Newguy is spot on about encapsulating printf's. That is one that can use
a _lot_ of space. Even if you can only wrapper a few of these, you may
well be surprised at what this can save.