Possible bug in Expl compiler

[Athul P]

A string containing colon symbol is not correctly parsed by the compiler.

tmp = exposcall("Write", -2, "Login:");  \\colon is present in the string

The assembly code generated by the compiler for the above statement is:

MOV R0,"Write"

PUSH R0

MOV R0,-2

PUSH R0

MOV R0,"" PUSH R0

PUSH R0

PUSH R0

CALL 0

The highlighted code causes INSTR_ERROR and the string is also empty.

[ishan ghosh]

Yes, this is a bug in the compiler or more like a special case that was not implemented.

myexpos/expl/ltranslate.l has something like

        [a-zA-Z0-9]+[:] {...}

This regex is used for label translation and it determines "Login:" as a label, it removes the occurrence of "Login:" from the string and checks if there are any instances of "Login" present to replace that with the address of the assumed label "Login:".

To fix the bug, add this code before the code above. Should be after "%%" in line 13 in ltranslate.l :

     \"(\\.|[^\\"])*\" {
     if(t)
     {
         fprintf(intermediate, "%s", yytext);
      } }

"make" the compiler again. What the above code does is ignores all the strings that are in quotes "" during label translation.

Word of caution: this has not been tested.

Best case scenario: just don't use colons":" in strings.

[Murali Krishnan]

I think the bug is with the XSM simulator rather than the compiler.  However since alphanumeric strings are permitted, we can ignore this issue.

We will try to fix it later.

Murali

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