[Tarantool-patches] [PATCH luajit] test: adapt tests checking debug line hook trace

[Tarantool-patches] [PATCH luajit] test: adapt tests checking debug line hook trace

[Maxim Kokryashkin via Tarantool-patches]

The LuaJIT's virtual machine interprets the bytecode
following the return from function (i.e. the one succeeding
the call made) and located on the line other than that return
bytecode, as a new line trigger for line hooks, unlike Lua
does.
Here is an example (it is joined in one line intend):

debug.sethook(function(_, l) print("LINE: "..l) end, "l") loadstring("\n\ns=nil")() debug.sethook()

This chunk prints for LuaJIT:

LINE: 3
LINE: 1

But for Lua 5.1 it is only "LINE: 3" in the output.
See also https://github.com/tarantool/tarantool/issues/5693.
Considering implementation-defined behaviour difference
(see also https://luajit.org/status.html) test is disabled for
LuaJIT.

Closes tarantool/tarantool#5693
Part of tarantool/tarantool#5845
Part of tarantool/tarantool#4473
---
Issue: https://github.com/tarantool/tarantool/issues/5693
GitHub branch: https://github.com/tarantool/luajit/tree/fckxorg/gh-5693-PUC-Rio-debug-line-hook

 test/PUC-Rio-Lua-5.1-tests/db.lua | 54 ++++++++++++++++---------------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/test/PUC-Rio-Lua-5.1-tests/db.lua b/test/PUC-Rio-Lua-5.1-tests/db.lua
index 56f59ea8..99efe8ef 100644
--- a/test/PUC-Rio-Lua-5.1-tests/db.lua
+++ b/test/PUC-Rio-Lua-5.1-tests/db.lua
@@ -8,6 +8,26 @@ do
 local a=1
 end
 
+-- The LuaJIT's virtual machine interprets the bytecode
+-- following the return from function (i.e. the one succeeding
+-- the call made) and located on the line other than that return
+-- bytecode, as a new line trigger for line hooks, unlike Lua
+-- does.
+-- Here is an example (it is joined in one line intend):
+--[[
+debug.sethook(function(_, l) print("LINE: "..l) end, "l") loadstring("\n\ns=nil")() debug.sethook()
+--]]
+-- This chunk prints for LuaJIT:
+--[[
+LINE: 3
+LINE: 1
+--]]
+-- But for Lua 5.1 it is only "LINE: 3" in the output.
+-- See also https://github.com/tarantool/tarantool/issues/5693.
+-- Considering implementation-defined behaviour difference
+-- (see also https://luajit.org/status.html) test is disabled for
+-- LuaJIT.
+-- This function is modified to correspond with LuaJIT's line triggers.
 function test (s, l, p)
   collectgarbage()   -- avoid gc during trace
   local function f (event, line)
@@ -16,7 +36,7 @@ function test (s, l, p)
     if p then print(l, line) end
     assert(l == line, "wrong trace!!")
   end
-  debug.sethook(f,"l"); loadstring(s)(); debug.sethook()
+  local cur_line = debug.getinfo(1).currentline; table.insert(l, 1, cur_line); table.insert(l, cur_line); debug.sethook(f,"l"); loadstring(s)(); debug.sethook()
   assert(table.getn(l) == 0)
 end
 
@@ -25,7 +45,7 @@ do
   local a = debug.getinfo(print)
   assert(a.what == "C" and a.short_src == "[C]")
   local b = debug.getinfo(test, "SfL")
-  assert(b.name == nil and b.what == "Lua" and b.linedefined == 11 and
+  assert(b.name == nil and b.what == "Lua" and b.linedefined == 31 and
          b.lastlinedefined == b.linedefined + 10 and
          b.func == test and not string.find(b.short_src, "%["))
   assert(b.activelines[b.linedefined + 1] and
@@ -95,26 +115,6 @@ repeat
   assert(g(f) == 'a')
 until 1
 
--- FIXME: The LuaJIT's virtual machine interprets the bytecode
--- following the return from function (i.e. the one succeeding
--- the call made) and located on the line other than that return
--- bytecode, as a new line trigger for line hooks, unlike Lua
--- does.
--- Here is an example (it is joined in one line intend):
---[[
-debug.sethook(function(_, l) print("LINE: "..l) end, "l") loadstring("\n\ns=nil")() debug.sethook()
---]]
--- This chunk prints for LuaJIT:
---[[
-LINE: 3
-LINE: 1
---]]
--- But for Lua 5.1 it is only "LINE: 3" in the output.
--- See also https://github.com/tarantool/tarantool/issues/5693.
--- Considering implementation-defined behaviour difference
--- (see also https://luajit.org/status.html) test is disabled for
--- LuaJIT.
---[=[
 test([[if
 math.sin(1)
 then
@@ -132,23 +132,25 @@ else
 end
 ]], {2,5,6})
 
+-- Test is adapted to the behaviour of LuaJIT.
 test([[a=1
 repeat
   a=a+1
 until a==3
-]], {1,3,4,3,4})
+]], {1,2,3,4,2,3,4})
 
 test([[ do
   return
 end
 ]], {2})
 
+-- Test is adapted to the behaviour of LuaJIT.
 test([[local a
 a=1
 while a<=3 do
   a=a+1
 end
-]], {2,3,4,3,4,3,4,3,5})
+]], {1,2,3,4,3,4,3,4,3,5})
 
 test([[while math.sin(1) do
   if math.sin(1)
@@ -168,8 +170,8 @@ test([[for i,v in pairs{'a','b'} do
 end
 ]], {1,2,1,2,1,3})
 
-test([[for i=1,4 do a=1 end]], {1,1,1,1,1})
---]=]
+-- Test is adapted to the behaviour of LuaJIT.
+test([[for i=1,4 do a=1 end]], {1,1,1,1})
 
 
 print'+'
-- 
2.33.0

Re: [Tarantool-patches] [PATCH luajit] test: adapt tests checking debug line hook trace

[Sergey Kaplun via Tarantool-patches]

Hi, Maxim!

Thanks for the patch!

Please consider my comments below.

On 24.09.21, Maxim Kokryashkin wrote:
> The LuaJIT's virtual machine interprets the bytecode
> following the return from function (i.e. the one succeeding
> the call made) and located on the line other than that return
> bytecode, as a new line trigger for line hooks, unlike Lua
> does.
> Here is an example (it is joined in one line intend):
> 
> debug.sethook(function(_, l) print("LINE: "..l) end, "l") loadstring("\n\ns=nil")() debug.sethook()
> 
> This chunk prints for LuaJIT:
> 
> LINE: 3
> LINE: 1
> 
> But for Lua 5.1 it is only "LINE: 3" in the output.
> See also https://github.com/tarantool/tarantool/issues/5693.
> Considering implementation-defined behaviour difference
> (see also https://luajit.org/status.html) test is disabled for
> LuaJIT.

But the commit adapts the test. Please describe how.

> 
> Closes tarantool/tarantool#5693
> Part of tarantool/tarantool#5845
> Part of tarantool/tarantool#4473

Looks like it should be 5870 instead 4473. Also, 5845 is already
closed.

> ---
> Issue: https://github.com/tarantool/tarantool/issues/5693
> GitHub branch: https://github.com/tarantool/luajit/tree/fckxorg/gh-5693-PUC-Rio-debug-line-hook
> 
>  test/PUC-Rio-Lua-5.1-tests/db.lua | 54 ++++++++++++++++---------------
>  1 file changed, 28 insertions(+), 26 deletions(-)
> 
> diff --git a/test/PUC-Rio-Lua-5.1-tests/db.lua b/test/PUC-Rio-Lua-5.1-tests/db.lua
> index 56f59ea8..99efe8ef 100644
> --- a/test/PUC-Rio-Lua-5.1-tests/db.lua
> +++ b/test/PUC-Rio-Lua-5.1-tests/db.lua
> @@ -8,6 +8,26 @@ do
>  local a=1
>  end
>  
> +-- The LuaJIT's virtual machine interprets the bytecode
> +-- following the return from function (i.e. the one succeeding
> +-- the call made) and located on the line other than that return
> +-- bytecode, as a new line trigger for line hooks, unlike Lua
> +-- does.
> +-- Here is an example (it is joined in one line intend):
> +--[[
> +debug.sethook(function(_, l) print("LINE: "..l) end, "l") loadstring("\n\ns=nil")() debug.sethook()
> +--]]
> +-- This chunk prints for LuaJIT:
> +--[[
> +LINE: 3
> +LINE: 1
> +--]]
> +-- But for Lua 5.1 it is only "LINE: 3" in the output.
> +-- See also https://github.com/tarantool/tarantool/issues/5693.
> +-- Considering implementation-defined behaviour difference
> +-- (see also https://luajit.org/status.html) test is disabled for
> +-- LuaJIT.

But it is not disabled after this commit.

> +-- This function is modified to correspond with LuaJIT's line triggers.
>  function test (s, l, p)
>    collectgarbage()   -- avoid gc during trace
>    local function f (event, line)
> @@ -16,7 +36,7 @@ function test (s, l, p)
>      if p then print(l, line) end
>      assert(l == line, "wrong trace!!")
>    end
> -  debug.sethook(f,"l"); loadstring(s)(); debug.sethook()
> +  local cur_line = debug.getinfo(1).currentline; table.insert(l, 1, cur_line); table.insert(l, cur_line); debug.sethook(f,"l"); loadstring(s)(); debug.sethook()

For what do we need additional insert? And why is it on the same line?

>    assert(table.getn(l) == 0)
>  end
>  
> @@ -25,7 +45,7 @@ do

<snipped>

> @@ -168,8 +170,8 @@ test([[for i,v in pairs{'a','b'} do
>  end
>  ]], {1,2,1,2,1,3})
>  
> -test([[for i=1,4 do a=1 end]], {1,1,1,1,1})
> ---]=]
> +-- Test is adapted to the behaviour of LuaJIT.
> +test([[for i=1,4 do a=1 end]], {1,1,1,1})

Why are there 4 entries instead 5?

>  
>  
>  print'+'
> -- 
> 2.33.0
> 

-- 
Best regards,
Sergey Kaplun