Assembling Debug Information

A production Muq compiler needs to do more than generate code that executes successfully: It should also document that code well enough to support symbolic debugging, including:

• The source code used to generate the compiledFunction.
• The name of the function, if provided by the user.
• The names of local variables used.
• The line number in the source code of each instruction.
• The name of the file containing the source, if any.

We have already seen that the names of local variables may be documented via assembleVariableSlot, and that the name of the function may be documented by setting fun$s.name. The remaining items may be recorded as follows:

• The name of the source file may be stored in asm$s.fileName: The assembler will copy it to fun$s.fileName. You may also set the latter directly.
• The location of the first line of the function within the source file may be recorded in asm$s.file-line: The assembler will copy it to fun$s.fileLine. You may also set the latter directly. Note that the first line in the file is line zero, for this purpose.
• The source code for the function should be stored in fun$s.source.
• The line number in the source corresponding to the instructions being assembled should be recorded in asm$s.line-number. This may be set directly, or via assemble-line-number, which is somewhat faster. This information winds up in fun$s.lineNumbers, but you shouldn't manipulate the latter directly, as its format is likely to change in future releases. These line numbers should start at zero for the first line of code in the function: If the line number within the source file is later desired, fun$s.fileLine may be added in.

Go to the first, previous, next, last section, table of contents.