Translator – Assignments and INSTR

While debugging assignments of temporary strings, specifically the assignment of a string that needs to be attached to the assignment operator, done stack empty errors were occurring. This was caused because it was trying to attach two strings, only one of which was on the done stack. Somehow the number of strings member in the table entry was set to two – it appeared to be counting both operands even though a check was put in not to count the first operand of an assignment operator (and was working).

The problem was finally determined to be caused by the INSTR table entries. The assignment operator table entries and the INSTR table entries were sharing the same expression information structure instance. When the assignment operator entry was initialized, it properly set the number of strings to one. But when it processed the INSTR table entries, it changed the number of strings to two, since it was the same instance. This was corrected by giving the assignment operator entries their own instances of the expression information structure.

This corrected the assignment operator problem, but the INSTR functions were giving an “expected operator or close parentheses” error at the second comma of the three argument form of INSTR. This occurred because the associated INSTR codes (Instr2T1, Instr2T2 and Instr2TT) did not have the multiple flag set. This was corrected by setting the multiple flag in the T1, T2 and TT forms of the Instr2 code entries, and the Instr3 associated code entries were placed after each of their corresponding Instr2 codes.