[Tarantool-patches] [PATCH luajit] dbg: display fast function name along with ffid

[Tarantool-patches] [PATCH luajit] dbg: display fast function name along with ffid

[Mikhail Elhimov via Tarantool-patches]

Part of tarantool/tarantool#4808
---
This patch is to be applied after the 'avoid hardcoded enums' patch.

Branch: https://github.com/tarantool/luajit/tree/elhimov/gh-4808-display-fast-function-name
Related issue: https://github.com/tarantool/tarantool/issues/4808

 src/luajit_dbg.py                               | 17 +++++++++++------
 .../debug-extension-tests.py                    |  2 +-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py
index 1ac1d275..262fdad1 100644
--- a/src/luajit_dbg.py
+++ b/src/luajit_dbg.py
@@ -1682,8 +1682,11 @@ def ir_kint64(ir):
 
 # Dumpers.
 
+FF_NAMES = EnumBasedList('FastFunc', 'FF__MAX', cut_prefix, 'FF_')
+
 # GCobj dumpers.
 
+
 def dump_lj_gco_str(gcobj):
     return 'string {body} @ {address}'.format(
         body=strdata(gcobj),
@@ -1705,7 +1708,7 @@ def dump_lj_gco_proto(gcobj):
 
 def dump_lj_gco_func(gcobj):
     func = dbg.cast('struct GCfuncC *', gcobj)
-    ffid = func['ffid']
+    ffid = int(func['ffid'])
 
     if ffid == 0:
         pt = funcproto(func)
@@ -1718,7 +1721,8 @@ def dump_lj_gco_func(gcobj):
     elif ffid == 1:
         return 'C function @ {}'.format(strx64(func['f']))
     else:
-        return 'fast function #{}'.format(int(ffid))
+        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
+        return 'fast function #{}({})'.format(ffid, ffname)
 
 
 def dump_lj_gco_trace(gcobj):
@@ -2068,7 +2072,7 @@ def dump_proto(proto):
 
 
 def dump_func(func):
-    ffid = func['ffid']
+    ffid = int(func['ffid'])
 
     if ffid == 0:
         pt = funcproto(func)
@@ -2076,7 +2080,8 @@ def dump_func(func):
     elif ffid == 1:
         return 'C function @ {}\n'.format(strx64(func['f']))
     else:
-        return 'fast function #{}\n'.format(int(ffid))
+        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
+        return 'fast function #{}({})\n'.format(ffid, ffname)
 
 
 # FFI dumpers.
@@ -2702,7 +2707,7 @@ the type and some info related to it.
 * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
   <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
   <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
+  <FFUNC>: fast function #<ffid>(<ffname>)
 * LJ_TTRACE: trace <traceno> @ <gcr>
 * LJ_TCDATA: cdata @ <gcr>
 * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
@@ -2921,7 +2926,7 @@ the type and some info related to it.
 * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
   <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
   <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
+  <FFUNC>: fast function #<ffid>(<ffname>)
 * LJ_TTRACE: trace <traceno> @ <gcr>
 * LJ_TCDATA: cdata @ <gcr>
 * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py
index 9989032b..40a27c3a 100644
--- a/test/tarantool-debugger-tests/debug-extension-tests.py
+++ b/test/tarantool-debugger-tests/debug-extension-tests.py
@@ -338,7 +338,7 @@ GCO_RX = (
     r'thread @ ' + RX_ADDR + r'\n'
     r'Lua function @ ' + RX_ADDR + r', [0-9]+ upvalues, .+:[0-9]+\n'
     r'C function @ ' + RX_ADDR + r'\n'
-    r'fast function #[0-9]+\n'
+    r'fast function #[0-9]+\(\w+\)\n'
     r'cdata @ ' + RX_ADDR + r' \[\d+\] <int \*> 0x0\n'
     r'table @ ' + RX_ADDR + r' \(asize: \d+, hmask: ' + RX_HASH + r'\)\n'
     r'userdata @ ' + RX_ADDR + r'\n'
-- 
2.43.0

Re: [Tarantool-patches] [PATCH luajit] dbg: display fast function name along with ffid

[Sergey Kaplun via Tarantool-patches]

Hi, Mikhail!
Thanks for the patch!
Generally, LGTM, with minor suggestions below.

On 09.09.26, Mikhail Elhimov wrote:
> Part of tarantool/tarantool#4808
> ---
> This patch is to be applied after the 'avoid hardcoded enums' patch.
> 
> Branch: https://github.com/tarantool/luajit/tree/elhimov/gh-4808-display-fast-function-name
> Related issue: https://github.com/tarantool/tarantool/issues/4808
> 
>  src/luajit_dbg.py                               | 17 +++++++++++------
>  .../debug-extension-tests.py                    |  2 +-
>  2 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py
> index 1ac1d275..262fdad1 100644
> --- a/src/luajit_dbg.py
> +++ b/src/luajit_dbg.py
> @@ -1682,8 +1682,11 @@ def ir_kint64(ir):
>  
>  # Dumpers.
>  
> +FF_NAMES = EnumBasedList('FastFunc', 'FF__MAX', cut_prefix, 'FF_')

It would be nice to replace `_` in functions names to `.`.
Resulting: math_min -> math.min

Minor: I would rather placed it somewhere into the section:
| # LuaJIT macro implementations and structure access.

> +
>  # GCobj dumpers.
>  
> +
>  def dump_lj_gco_str(gcobj):
>      return 'string {body} @ {address}'.format(
>          body=strdata(gcobj),
> @@ -1705,7 +1708,7 @@ def dump_lj_gco_proto(gcobj):
>  
>  def dump_lj_gco_func(gcobj):
>      func = dbg.cast('struct GCfuncC *', gcobj)
> -    ffid = func['ffid']
> +    ffid = int(func['ffid'])
>  
>      if ffid == 0:
>          pt = funcproto(func)
> @@ -1718,7 +1721,8 @@ def dump_lj_gco_func(gcobj):
>      elif ffid == 1:
>          return 'C function @ {}'.format(strx64(func['f']))
>      else:
> -        return 'fast function #{}'.format(int(ffid))
> +        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
> +        return 'fast function #{}({})'.format(ffid, ffname)

I suggest the following format insted:
| 'fast function {} (#{})'.format(ffname, ffid)

Generally we needed ffid less then the function name.

>  
>  
>  def dump_lj_gco_trace(gcobj):
> @@ -2068,7 +2072,7 @@ def dump_proto(proto):
>  
>  
>  def dump_func(func):
> -    ffid = func['ffid']
> +    ffid = int(func['ffid'])
>  
>      if ffid == 0:
>          pt = funcproto(func)
> @@ -2076,7 +2080,8 @@ def dump_func(func):
>      elif ffid == 1:
>          return 'C function @ {}\n'.format(strx64(func['f']))
>      else:
> -        return 'fast function #{}\n'.format(int(ffid))
> +        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
> +        return 'fast function #{}({})\n'.format(ffid, ffname)

I suggest the following format insted:
| 'fast function {} (#{})\n'.format(ffname, ffid)

Generally we needed ffid less then the function name.

>  
>  
>  # FFI dumpers.
> @@ -2702,7 +2707,7 @@ the type and some info related to it.
>  * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
>    <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
>    <CFUNC>: C function <mcode address>
> -  <FFUNC>: fast function #<ffid>
> +  <FFUNC>: fast function #<ffid>(<ffname>)

I suggest the following format instead:

| <FFUNC>: fast function <ffname> (#<ffid>)

>  * LJ_TTRACE: trace <traceno> @ <gcr>
>  * LJ_TCDATA: cdata @ <gcr>
>  * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
> @@ -2921,7 +2926,7 @@ the type and some info related to it.
>  * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
>    <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
>    <CFUNC>: C function <mcode address>
> -  <FFUNC>: fast function #<ffid>

I suggest the following format instead:

| <FFUNC>: fast function <ffname> (#<ffid>)

> +  <FFUNC>: fast function #<ffid>(<ffname>)
>  * LJ_TTRACE: trace <traceno> @ <gcr>
>  * LJ_TCDATA: cdata @ <gcr>
>  * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
> diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py
> index 9989032b..40a27c3a 100644
> --- a/test/tarantool-debugger-tests/debug-extension-tests.py
> +++ b/test/tarantool-debugger-tests/debug-extension-tests.py
> @@ -338,7 +338,7 @@ GCO_RX = (
>      r'thread @ ' + RX_ADDR + r'\n'
>      r'Lua function @ ' + RX_ADDR + r', [0-9]+ upvalues, .+:[0-9]+\n'
>      r'C function @ ' + RX_ADDR + r'\n'
> -    r'fast function #[0-9]+\n'
> +    r'fast function #[0-9]+\(\w+\)\n'

Lets check the specific name here. I suggest `math.min` to check the
_ -> . mapping.

>      r'cdata @ ' + RX_ADDR + r' \[\d+\] <int \*> 0x0\n'
>      r'table @ ' + RX_ADDR + r' \(asize: \d+, hmask: ' + RX_HASH + r'\)\n'
>      r'userdata @ ' + RX_ADDR + r'\n'
> -- 
> 2.43.0
> 

-- 
Best regards,
Sergey Kaplun

Re: [Tarantool-patches] [PATCH luajit] dbg: display fast function name along with ffid

[Mikhail Elhimov via Tarantool-patches]

Hi, Sergey!

Thanks for the review! See my comments below

On 22.09.2026 12:16, Sergey Kaplun wrote:
> Hi, Mikhail!
> Thanks for the patch!
> Generally, LGTM, with minor suggestions below.
>
> On 09.09.26, Mikhail Elhimov wrote:
>> Part of tarantool/tarantool#4808
>> ---
>> This patch is to be applied after the 'avoid hardcoded enums' patch.
>>
>> Branch: https://github.com/tarantool/luajit/tree/elhimov/gh-4808-display-fast-function-name
>> Related issue: https://github.com/tarantool/tarantool/issues/4808
>>
>>   src/luajit_dbg.py                               | 17 +++++++++++------
>>   .../debug-extension-tests.py                    |  2 +-
>>   2 files changed, 12 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py
>> index 1ac1d275..262fdad1 100644
>> --- a/src/luajit_dbg.py
>> +++ b/src/luajit_dbg.py
>> @@ -1682,8 +1682,11 @@ def ir_kint64(ir):
>>   
>>   # Dumpers.
>>   
>> +FF_NAMES = EnumBasedList('FastFunc', 'FF__MAX', cut_prefix, 'FF_')
> It would be nice to replace `_` in functions names to `.`.
> Resulting: math_min -> math.min

Then what about these and similar ones (they have 3 underscores in a row):

ffi_meta___index

io_method___gc

?

May be replace only first underscore?

> Minor: I would rather placed it somewhere into the section:
> | # LuaJIT macro implementations and structure access.
Done
>> +
>>   # GCobj dumpers.
>>   
>> +
>>   def dump_lj_gco_str(gcobj):
>>       return 'string {body} @ {address}'.format(
>>           body=strdata(gcobj),
>> @@ -1705,7 +1708,7 @@ def dump_lj_gco_proto(gcobj):
>>   
>>   def dump_lj_gco_func(gcobj):
>>       func = dbg.cast('struct GCfuncC *', gcobj)
>> -    ffid = func['ffid']
>> +    ffid = int(func['ffid'])
>>   
>>       if ffid == 0:
>>           pt = funcproto(func)
>> @@ -1718,7 +1721,8 @@ def dump_lj_gco_func(gcobj):
>>       elif ffid == 1:
>>           return 'C function @ {}'.format(strx64(func['f']))
>>       else:
>> -        return 'fast function #{}'.format(int(ffid))
>> +        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
>> +        return 'fast function #{}({})'.format(ffid, ffname)
> I suggest the following format insted:
> | 'fast function {} (#{})'.format(ffname, ffid)
>
> Generally we needed ffid less then the function name.
Done
>>   
>>   
>>   def dump_lj_gco_trace(gcobj):
>> @@ -2068,7 +2072,7 @@ def dump_proto(proto):
>>   
>>   
>>   def dump_func(func):
>> -    ffid = func['ffid']
>> +    ffid = int(func['ffid'])
>>   
>>       if ffid == 0:
>>           pt = funcproto(func)
>> @@ -2076,7 +2080,8 @@ def dump_func(func):
>>       elif ffid == 1:
>>           return 'C function @ {}\n'.format(strx64(func['f']))
>>       else:
>> -        return 'fast function #{}\n'.format(int(ffid))
>> +        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
>> +        return 'fast function #{}({})\n'.format(ffid, ffname)
> I suggest the following format insted:
> | 'fast function {} (#{})\n'.format(ffname, ffid)
>
> Generally we needed ffid less then the function name.
Done
>>   
>>   
>>   # FFI dumpers.
>> @@ -2702,7 +2707,7 @@ the type and some info related to it.
>>   * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
>>     <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
>>     <CFUNC>: C function <mcode address>
>> -  <FFUNC>: fast function #<ffid>
>> +  <FFUNC>: fast function #<ffid>(<ffname>)
> I suggest the following format instead:
>
> | <FFUNC>: fast function <ffname> (#<ffid>)
Done
>>   * LJ_TTRACE: trace <traceno> @ <gcr>
>>   * LJ_TCDATA: cdata @ <gcr>
>>   * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
>> @@ -2921,7 +2926,7 @@ the type and some info related to it.
>>   * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
>>     <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
>>     <CFUNC>: C function <mcode address>
>> -  <FFUNC>: fast function #<ffid>
> I suggest the following format instead:
>
> | <FFUNC>: fast function <ffname> (#<ffid>)
Done
>> +  <FFUNC>: fast function #<ffid>(<ffname>)
>>   * LJ_TTRACE: trace <traceno> @ <gcr>
>>   * LJ_TCDATA: cdata @ <gcr>
>>   * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
>> diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py
>> index 9989032b..40a27c3a 100644
>> --- a/test/tarantool-debugger-tests/debug-extension-tests.py
>> +++ b/test/tarantool-debugger-tests/debug-extension-tests.py
>> @@ -338,7 +338,7 @@ GCO_RX = (
>>       r'thread @ ' + RX_ADDR + r'\n'
>>       r'Lua function @ ' + RX_ADDR + r', [0-9]+ upvalues, .+:[0-9]+\n'
>>       r'C function @ ' + RX_ADDR + r'\n'
>> -    r'fast function #[0-9]+\n'
>> +    r'fast function #[0-9]+\(\w+\)\n'
> Lets check the specific name here. I suggest `math.min` to check the
> _ -> . mapping.
No problem, but first we need to agree on how to handle underscores (see 
above comment about multiple undescores)
>
>> ing     r'cdata @ ' + RX_ADDR + r' \[\d+\] <int \*> 0x0\n'
>>       r'table @ ' + RX_ADDR + r' \(asize: \d+, hmask: ' + RX_HASH + r'\)\n'
>>       r'userdata @ ' + RX_ADDR + r'\n'
>> -- 
>> 2.43.0
>>
-- 
Best regards,
Mikhail Elhimov

[Tarantool-patches] [PATCH luajit v2] dbg: display fast function name along with ffid

[Mikhail Elhimov via Tarantool-patches]

Part of tarantool/tarantool#4808
---
Changes in v2:
  - Format is changed to 'ffname (#ffid)'
  - Replaced single '_' with '.' in ffname
  - Adjusted tests to check mapping

This patch is to be applied after https://lists.tarantool.org/pipermail/tarantool-patches/2026-September/030791.html.

Branch: https://github.com/tarantool/luajit/tree/elhimov/gh-4808-display-fast-function-name
Related issue: https://github.com/tarantool/tarantool/issues/4808

 src/luajit_dbg.py                             | 19 +++++++++++++------
 .../debug-extension-tests.py                  |  6 ++++--
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py
index 5cd23a88..a564801b 100644
--- a/src/luajit_dbg.py
+++ b/src/luajit_dbg.py
@@ -1121,6 +1121,11 @@ def frames(L):
 # LuaJIT macro implementations and structure access.
 
 
+# Get FastFunc enum members and replace any single '_' with '.'.
+FF_NAMES = EnumBasedList('FastFunc', 'FF__MAX', lambda x:
+                         re.sub('(?<!_)_(?!_)', '.', cut_prefix(x, 'FF_')))
+
+
 def mref(typename, obj):
     return dbg.cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32'])
 
@@ -1716,7 +1721,7 @@ def dump_lj_gco_proto(gcobj):
 
 def dump_lj_gco_func(gcobj):
     func = dbg.cast('struct GCfuncC *', gcobj)
-    ffid = func['ffid']
+    ffid = int(func['ffid'])
 
     if ffid == 0:
         pt = funcproto(func)
@@ -1729,7 +1734,8 @@ def dump_lj_gco_func(gcobj):
     elif ffid == 1:
         return 'C function @ {}'.format(strx64(func['f']))
     else:
-        return 'fast function #{}'.format(int(ffid))
+        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
+        return 'fast function {} (#{})'.format(ffname, ffid)
 
 
 def dump_lj_gco_trace(gcobj):
@@ -2079,7 +2085,7 @@ def dump_proto(proto):
 
 
 def dump_func(func):
-    ffid = func['ffid']
+    ffid = int(func['ffid'])
 
     if ffid == 0:
         pt = funcproto(func)
@@ -2087,7 +2093,8 @@ def dump_func(func):
     elif ffid == 1:
         return 'C function @ {}\n'.format(strx64(func['f']))
     else:
-        return 'fast function #{}\n'.format(int(ffid))
+        ffname = FF_NAMES[ffid] if ffid < len(FF_NAMES) else "unknown"
+        return 'fast function {} (#{})\n'.format(ffname, ffid)
 
 
 # FFI dumpers.
@@ -2713,7 +2720,7 @@ the type and some info related to it.
 * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
   <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
   <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
+  <FFUNC>: fast function <ffname> (#<ffid>)
 * LJ_TTRACE: trace <traceno> @ <gcr>
 * LJ_TCDATA: cdata @ <gcr>
 * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
@@ -2932,7 +2939,7 @@ the type and some info related to it.
 * LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
   <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
   <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
+  <FFUNC>: fast function <ffname> (#<ffid>)
 * LJ_TTRACE: trace <traceno> @ <gcr>
 * LJ_TCDATA: cdata @ <gcr>
 * LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py
index 5e369f00..86954909 100644
--- a/test/tarantool-debugger-tests/debug-extension-tests.py
+++ b/test/tarantool-debugger-tests/debug-extension-tests.py
@@ -326,7 +326,7 @@ GCO_ARGS = (
     'coroutine.create(function() end),\n'
     'function() end,\n'
     'require,\n'
-    'print,\n'
+    'math.min,\n'
     'ffi.new("int*"),\n'
     '{1},\n'
     'newproxy(),\n'
@@ -338,7 +338,7 @@ GCO_RX = (
     r'thread @ ' + RX_ADDR + r'\n'
     r'Lua function @ ' + RX_ADDR + r', [0-9]+ upvalues, .+:[0-9]+\n'
     r'C function @ ' + RX_ADDR + r'\n'
-    r'fast function #[0-9]+\n'
+    r'fast function math.min (#[0-9]+)\n'
     r'cdata @ ' + RX_ADDR + r' \[\d+\] <int \*> 0x0\n'
     r'table @ ' + RX_ADDR + r' \(asize: \d+, hmask: ' + RX_HASH + r'\)\n'
     r'userdata @ ' + RX_ADDR + r'\n'
@@ -367,6 +367,7 @@ class TestLJTV(TestCaseBase):
     # Sorted in LJT order.
     lua_script = (
         'local ffi = require("ffi")\n'
+        'local math = require("math")\n'
         'print(\n'
         '  nil,\n'
         '  false,\n'
@@ -435,6 +436,7 @@ class TestLJGCo(TestCaseBase):
 
     lua_script = (
         'local ffi = require("ffi")\n'
+        'local math = require("math")\n'
         'print(\n' +
         GCO_ARGS +
         '  1\n'  # Stub for the pattern.
-- 
2.43.0