enum syntax error

TonyG · Joined: 22 Dec 2008 Posts: 6

I just started workong on my first project using the PICC compiler (v4.065) integrated with MPLAB (v8.10). I'm trying to compile some code written for previous projects, and I'm running into a problem with a line that is valid C syntax. Here's a code sample to demonstrate the problem:

TonyG · Joined: 22 Dec 2008 Posts: 6

I've noticed that this problem doesn't occur when the enumeration is a return parameter. For example, the following code compiles with no errors:

TonyG · Joined: 22 Dec 2008 Posts: 6

I've run into another error with valid C syntax. When I compile this following code:

TonyG · Joined: 22 Dec 2008 Posts: 6

Here's another compiler error about valid C syntax:

TonyG · Joined: 22 Dec 2008 Posts: 6

One of the compilers I'm using supports a pragma statement for specifying structure packing. The statement is: "#pragma pack (1)". This pragma is of course not recognized by the PICC compiler. The ANSI 89 standard states that an unrecognized pragma should be ignored, but the PICC compiler generates the following error:

*** Error 7 "File.h" Line 39(9,13): Invalid Pre-Processor directive

Is there a list somewhere of all the ANSI 89 rules that the compiler doesn't follow?

dyeatman · Joined: 06 Sep 2003 Posts: 1923 Location: Norman, OK

Tony,
The subject has been brought up a number of times previously on this board. The answer to your question is no, this compiler is not intended to be fully ANSI compliant. Typically PIC related embedded compilers are not fully ANSI compliant due to the special requirements working with the PIC processors.

TonyG · Joined: 22 Dec 2008 Posts: 6

Dyeatman,

Thanks for the reply. I realize that embedded compilers require adaptations. I've used Keil, IAR, Greenhills, and GNU before, so I'm familiar with these issues. Unfortunately the problems I'm having aren't related to embedded issues. For example, there should be no difference between:

int8 x = Func();

and:

int8 x;
x = Func();

but the compiler will only accept the latter.

Is there a FAQ or general thread that gives a detailed list of areas where the PICC compiler is not compliant with ANSI 89?

dyeatman · Joined: 06 Sep 2003 Posts: 1923 Location: Norman, OK

I have been around this board for quite a few years and have never seen any
kind of list like you are seeking. I have seen a few things recently where CCS
is working to make significant improvements to compatibility in version
4.100 I also heard that they plan to make it possible with version 4.100 (??)
to compile C18 code....don't know if this is really true. I would recommend
sending them the examples to see if they can include them in the upgrade.

Ttelmah · Guest

Some comments.

The inability to initialise from a function, is in the manual. It specifically says that the initialising value, is 'cexpr', with the comment below that 'cexpr, is a constant expression'. Though it may well 'appear' the same to initialise, then set a value to a returned value from a function, in code terms it isn't. The way that the CCS compiler works, it distinguishes stuff it puts into the 'initialisation header', from stuff in the main program. I must admit it'd not seem hard now to allow such initialisations, but it doesn't.

The enum is quite interesting. It actually implies that the compiler is not making enum definitions made outside the main functions 'global'. Historically, an enum definition, needs to be in the same 'scope' as the operation using them, and normally (in common with other defintions), anything declared outside of all functions, is 'global'. It appears that in the case of an enum, CCS is not doing this. It appears as if things inside function defintions, are being treated as having the 'scope' of the function, rather than beng global. This is why it works for the return parameter (in the external scope), but not for the calling parameters.
So you can do this, if you either typedef the enum, or declare it inside the scope of the function. So: