Inline assembly broken in IAR 5.5x

[ransford]

For the 5.5x and later versions of their compiler, IAR changed the rules for inline assembly such that you can no longer do things like this:

asm("foobar:");
asm("MOV R1, R2");
asm("JMP foobar");

You get an error message like

unknown symbol in inline assembly

The fix will be to tidy up the parts of the WISP firmware that have asm statements referencing labels created in other asm statements. Where possible, collapse runs of asm statements into one. The above would become:

    asm volatile ("foobar\n\t" // oh yeah, and use volatile
                  "MOV R1, R2\n\t"
                  "JMP foobar");

[ransford]

I've tested a patch that is backward compatible with IAR 5.4x and will merge it shortly.

[ransford]

The patch for IAR 5.5x is ready; check out the iar550 branch. I'm trying to get someone to test that branch against IAR 5.4x; then I'll merge the patch into master.

[impedimentToProgress]

I got an error with both the volatile keyword and the label using the kickstarter version of IAR (5.52).

[ransford]

@impedimentToProgress Can you be more specific about what you did and what happened?

[impedimentToProgress]

For simplicity I added your code to the blinky LED example that comes with IAR and attepmted to compile it. Here are the error messages when I leave in the volatile keyword,

msp430x2xx_fet_1.c
Error[Pe125]: expected a "(" C:\Users\Matt\Desktop\430\examples\examples\Flashing the LED\Flashing the LED\msp430x2xx\C-source\msp430x2xx_fet_1.c 31
Error while running C/C++ Compiler

Done. 1 error(s), 0 warning(s)

Here is the error message that I get when I remove the volatile keyword, but leave the rest of the code intact,

msp430x2xx_fet_1.c
Error[Og005]: Unknown symbol in inline assembly: "foobar" C:\Users\Matt\Desktop\430\examples\examples\Flashing the LED\Flashing the LED\msp430x2xx\C-source\msp430x2xx_fet_1.c 31
Error[Og006]: Syntax error in inline assembly: "Error[54]: Expression can not be forward" C:\Users\Matt\Desktop\430\examples\examples\Flashing the LED\Flashing the LED\msp430x2xx\C-source\msp430x2xx_fet_1.c 31
Error[Og005]: Unknown symbol in inline assembly: "foobar" C:\Users\Matt\Desktop\430\examples\examples\Flashing the LED\Flashing the LED\msp430x2xx\C-source\msp430x2xx_fet_1.c 33
Error[Og006]: Syntax error in inline assembly: "Error[54]: Expression can not be forward" C:\Users\Matt\Desktop\430\examples\examples\Flashing the LED\Flashing the LED\msp430x2xx\C-source\msp430x2xx_fet_1.c 33
Error while running C/C++ Compiler

Done. 4 error(s), 0 warning(s)

[impedimentToProgress]

This code compiles correctly,

asm(
"foobar:\n\t"
"MOV R1, R2\n\t"
"JMP foobar"
);

Note the addition of the colon. Volatile still causes an error. Also not that if we wanted to have code before the label, we would have to make sure the label is on the left margin:

asm(
"ADD R1, R2 \n"
"foobar: \n\t"
"MOV R1, R2 \n\t"
"JMP foobar"
);

or else IAR doesn't recognize it as a label.

[ransford]

Thanks for those extra details. You are right that volatile is a no-no and that labels need special formatting (left justification and trailing colon); my original suggestion in the first comment was incorrect.

I am about to merge the iar550 branch into master; it already incorporates these corrections.