OK, I was looking into the dwarf section problem when I noticed there is a "-dA" command line option for gcc to comment all the emitted dwarf values. This is great, since bouncing between compiler source, emitted assembly and the Dwarf2 specification was getting old. Sadly, I found an assembler problem. GAS is misinterpreting the "*" comment character as an arithmetic operator. Any other text is treated as the start of a new instruction.

eric@compaq:~/dev/tios/src/temp$ cat emw3.s
      data 0x1234 * stupid comment
eric@compaq:~/dev/tios/src/temp$ tms9900-as emw3.s
emw3.s: Assembler messages:
emw3.s:1: Error: unknown instruction 'comment'

Not super helpful. I can filter out everything after the first space in the comment, but what about the first word? What if that first word is a valid symbol or number? We could have multiple ways to parse the line. For example:

      data COUNT *2 bytes allocated

Is the two supposed to be an operand or a comment? TI allows unadorned comments at the end of the line so the comment could be either "2 bytes allocated" or "bytes allocated". TI got around this by forbidding spaces in expressions. So the two in the line above would be considered part of the comment.

This should be super fun to fix, since the assembler eats a lot of spaces before we get to see the contents of the input file.