This information has been added to file
"InterMSP430CompilerPortability.h".

To assist with code portability between compilers and assemblers
use can be made of predefined macro names.

For example
1. Suppose you use Code Composer Essentials and IAR V3 tool sets
2. Suppose you have both C and assembler
3. Suppose it is important to know if an include file is being used
    for assembler or C as well as knowing which tool set is being used

Then the following code, say in file "target.h" takes advantage of
predefined macros from the tool sets. The TOOLSET macro name is a
reference to C code for setting macros for interrupt use and
optimised switch statements in file
"InterMSP430CompilerPortability.h".

//say this file is in target.h
#ifdef __TI_COMPILER_VERSION__ 
//Code Composer Essentials  compiler and assembler
 #define TOOLSET TOOLSET_TICCE
 #ifdef __ASM_HEADER__
  #define CCEA //Code Composer Essentials assembler
 #else
  #define CCEC //Code Composer Essentials compiler
 #endif
#else
 #ifdef __IAR_SYSTEMS_ICC__
  #define TOOLSET TOOLSET_IAR
  #define IARC //IAR C Compiler
 #else
  #ifdef __IAR_SYSTEMS_ASM__
   //defining a TOOLSET here is pointless.
   #define IARA //IAR Assembler
  #else
    #error "Unrecognised MSP430 compiler or assembler"
  #endif
 #endif
#endif

While IAR has similar preprocessing language constructs between
C and assembler, Code Composer Essentials provides a facility
to convert a wider range of useful information from C using 
the .cdecls directive. However the .cdecls directive
cannot be used on pure assembly.

There is also another problem. Code Composer Essentials assembler
will only define __ASM_HEADER__ for sections belonging to 
a .cdecls directive. For pure assembly the preprocessor 
symbol .MSP430 is defined

For example the following is pure assembly that will only 
assemble 'as is' with Code Composer Essentials. 
Code Composer Essentials uses a '.' instead of '#' to 
indicate a preprocessor directive.


  .if .MSP430
    .sect ".some_section"
  .else
    RSEG SOME_SECTION
  .endif

To make this assembler file assemble correctly under IAR it needs
to be run through an external program that will convert .if to #if,
.else to #else, .endif to #endif and will convert .MSP430 to a 
valid but undefined symbol name under IAR assembler, such 
as _MSP430. Since _MSP430 should not be defined under IAR,
the IAR assembler will make the correct choice.

It is very simple to do this. For example all of the above can
be accomplished with the following single command that can 
be placed in a command file.
sed -e 's/\.MSP430/_MSP430/' -e 's/\.if/#if/' -e
's/\.else/#else/'
join with line above: -e 's/\.endif/#endif/' file.asm > file.s43

sed is standard program in Unix and Linux distributions.
There are versions of sed compiled for Windows for example
http://gnuwin32.sourceforge.net/packages/sed.htm

I have also made it easier to manage the addition of 
new interrupts through use of the preprocessor macro 
argument concatenation operator ##. While it might seem
an obvious approach to make, it is not as successful 
as might be hoped: two lines are necessary for each
interrupt name in "InterMSP430CompilerPortability.h".
It is not possible to use #pragma in a macro and under
IAR the preprocessor operator _Pragma must have its 
sole argument quoted and stubbornly refuses to 
work with substitutions that are quotes 
(for example #define QP(A) _Pragma(#A) does not work)

Tests with a debugger have been conducted for both 
Code Composer Essentials and IRA V3. Tests have 
not been conducted for GCC and Crossworks.

John Heenan

Hi John!

> I have also made it easier to manage the addition
of 
> new interrupts through use of the preprocessor macro 
> argument concatenation operator ##. While it might seem
> an obvious approach to make, it is not as successful 
> as might be hoped: two lines are necessary for each
> interrupt name in "InterMSP430CompilerPortability.h".

> It is not possible to use #pragma in a macro and
under
> IAR the preprocessor operator _Pragma must have its 
> sole argument quoted and stubbornly refuses to 
> work with substitutions that are quotes 
> (for example #define QP(A) _Pragma(#A) does not work)

It sure does; and for good reasons too -- that is the way the it should 
work, according to the standard.

However, I think that I have a solution that work, but I had to dig 
quite deep into my bag of preprocessor tricks to manage it:

#define STRANGE_VECTOR 100    // Just for the example


// Concatenate two identifiers
#define CONCAT0(x,y) x##y
#define CONCAT(x,y) CONCAT0(x,y)

// PRAGMA, unlike _Pragma it don't want its arguments quoted.
#define PRAGMA(x) _Pragma(#x)

// PV - pragma vector.
#define PV0(x) PRAGMA(vector=x)
#define PV(x) PV0(CONCAT(x,_VECTOR))


PV(STRANGE)
__interrupt void foo(void)
{
}


John, keep up the good work maintaining the MSP430 interop file!

     -- Anders Lindgren, IAR Systems
-- 
Disclaimer: Opinions expressed in this posting are strictly my own and
not necessarily those of my employer.