Debugging from Coq toplevel using Caml trace mechanism
======================================================

  1. Launch bytecode version of Coq (coqtop.byte)
  2. Access Ocaml toplevel using vernacular command 'Drop.'
  3. Install load paths and pretty printers for terms, idents, ... using
     Ocaml command '#use "base_include";;' (use '#use "include";;' for 
     installing the advanced term pretty printers)
  4. Use #trace to tell which function(s) to trace
  5. Go back to Coq toplevel with 'go();;'
  6. Test your Coq command and observe the result of tracing your functions
  7. Freely switch from Coq to Ocaml toplevels with 'Drop.' and 'go();;'

  You can avoid typing #use "include" (or "base_include") after Drop
  by adding the following lines in your $HOME/.ocamlinit :

   if Filename.basename Sys.argv.(0) = "coqtop.byte"
   then ignore (Toploop.use_silently Format.std_formatter "include")

  Hints: To remove high-level pretty-printing features (coercions,
  notations, ...), use "Set Printing All". It will affect the #trace
  printers too.


Debugging from Caml debugger
============================

   Requires [Tuareg mode](https://github.com/ocaml/tuareg) in Emacs.\
   Coq must be configured with `-local` (`./configure -local`) and the
   byte-code version of `coqtop` must have been generated with `make byte`.

   1. M-x camldebug
   2. give the binary name bin/coqtop.byte
   3. give ../dev/ocamldebug-coq
   4. source db  (to get pretty-printers)
   5. add breakpoints with C-x C-a C-b from the buffer displaying the ocaml
      source
   6. get more help from ocamldebug manual
         run
	 step
         back
         start
	 next
	 last
	 print x (abbreviated into p x)
	 ...
   7. some hints: 

   - To debug a failure/error/anomaly, add a breakpoint in
     Vernac.vernac_com at the with clause of the "try ... interp com
     with ..." block, then go "back" a few steps to find where the
     failure/error/anomaly has been raised
   - Alternatively, for an error or an anomaly, add breakpoints in the middle  
     of each of error* functions or anomaly* functions in lib/util.ml
   - If "source db" fails, do a "make printers" and try again (it should build
     top_printers.cmo and the core cma files).
   - If you have the OCAMLRUNPARAM environment variable set, Coq may hang on
     startup when run from the debugger. If this happens, unset the variable,
     re-start Emacs, and run the debugger again.

Global gprof-based profiling
============================

   Coq must be configured with option -profile

   1. Run native Coq which must end normally (use Quit or option -batch)
   2. gprof ./coqtop gmon.out

Per function profiling
======================

   To profile function foo in file bar.ml, add the following lines, just
   after the definition of the function:

     let fookey = Profile.declare_profile "foo";;
     let foo a b c = Profile.profile3 fookey foo a b c;;

   where foo is assumed to have three arguments (adapt using
   Profile.profile1, Profile. profile2, etc).

   This has the effect to cumulate the time passed in foo under a
   line of name "foo" which is displayed at the time coqtop exits.