CODEWITHSUNDEEP
debuggingluatrace
K Kay
K Kay

Reputation: 109

Tracing execution of Lua Sripts

I know you can use the debug library of lua to get some tracing info/debugging. But the information is in pieces. So I am wondering if there is a way to trace the execution of a Lua script. A step by step process. it would be required and it will automatically go thru at every execution step To produce a report such as the following;

Called: function xyz  from : Table abc
It has n parameters
Param 1: apples
Param 2: oranges
.
.

It has m returns
return 1: red
return 2: yellow
.
.

Called: function xyz2  from : Table abc2
It has n parameters
Param 1: pears
Param 2: bananas
.
.
It has m reruns
return 1: heavy
return 2: light
.
.

and so on....

Upvotes: 2

Views: 2046

Answers (1)

lhf
lhf

Reputation: 72312

Here is some code that used to be distributed in the Lua tarball. It's from 2005 and still works fine.

-- trace calls
-- example: lua -ltrace-calls bisect.lua

local level=0

local function hook(event)
 local t=debug.getinfo(3)
 io.write(level," >>> ",string.rep(" ",level))
 if t~=nil and t.currentline>=0 then io.write(t.short_src,":",t.currentline," ") end
 t=debug.getinfo(2)
 if event=="call" then
  level=level+1
 else
  level=level-1 if level<0 then level=0 end
 end
 if t.what=="main" then
  if event=="call" then
   io.write("begin ",t.short_src)
  else
   io.write("end ",t.short_src)
  end
 elseif t.what=="Lua" then
  io.write(event," ",t.name or "(Lua)"," <",t.linedefined,":",t.short_src,">")
 else
 io.write(event," ",t.name or "(C)"," [",t.what,"] ")
 end
 io.write("\n")
end

debug.sethook(hook,"cr")
level=0

Upvotes: 4

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