print-function-meta-info

Arguments: func &key (src t) (ask t) terse full sort vars mixed

Returns 0 values after printing information about func for side-effect. func can be a function or closure object or a function name.

If terse is true then 80 columns should be sufficient for the output, otherwise up to 150 columns may be required for the output. Normally, output is restricted to one line per information item. Source forms, when available, are printed using a concise-print technique whereby various values of *print-length* and *print-level* are tried until the whole form fits on one line. However, if full is true, no such testing is done, and whole forms are printed, possibly on multiple lines.

Up to four kinds of information currently presented, depending on various options. These are described more fully described in Printing function meta data are related topics in debugging.htm.

• Source debug info: these are records which serve as Lisp breakpoints, and which provide information about what is currently being executed at any particular program counter location. There may be multiple source records with same pc locations. If other information is being printed with these records, then the first column always starts with "S" for "source record".
• Disassembler output: generally, each one or two line record shows a single instruction at a program-counter location. No character is ever printed in the first column of disassembler output.
• Variable transition information: each record represents a transfer of a variable's value to or from a location, either a register or a memory location. Each variable record is printed on a separate line that starts with "V" (for "variable transition").
• Census information: a census point is a pc location which is likely to be seen by the precise-gc, and the census point provides information about what locations on the stack are alive at that pc location. Each Census point is printed on its own line starting with "C" (for "census point").

If src is non-nil (the default) and if source-level-debug info is available for func it is used, otherwise the output is presented without source information. If func has been compiled with comp:save-source-level-debug-info-switch on but the fasl file has not been loaded with *load-source-debug-info* on, then source info will be searched using the following steps:

1. If the fasl file was compiled with *record-source-file-info* true, and if *load-source-file-info* was true when the fasl file was loaded, then the location of the fasl file is implied and is re-loaded with only source-debug-info requested.
2. If the source-file information was not recorded or loaded, but source-debug info was recorded (and not loaded), and if ask is non-nil (the default) then a prompt is given asking for the name of the file to load. Any string representing the file can be specified, e.g. "dir/file.fasl", "dir/file", "dir/file.cl", etc. If the fasl file associated with the given name exists it is loaded for source debug info and that info becomes available.
3. If ask is nil, source-debug info is silently unused.

Information is presented in an order most appropriate for the options given. Sorting can be by requested by source-record (i.e. :rec), by program-counter (i.e. :pc), or by source-position (i.e. :pos). If no options are specified for this function, and if source is available, then only source records will be shown in record order. If src is nil or source-debug-info is unavailable, or if either of mixed or vars is non-nil, then the presentation will be made in program-counter order.

If mixed is t then assembler code is presented in a manner similar to disassemble, but intermixed with any other information (in program-counter order).

If vars is t, then variable transitions are presented, interspersed with other information (in program-counter order).

If sort is :pc for any reason, census points are presented, in pc order.

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page was not revised from the 10.0 page.
Created 2019.8.20.