From 94605bbaac7260f099e78377dd423a5627b8649f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20=C5=A0pa=C4=8Dek?= <petr.spacek@nic.cz>
Date: Sat, 16 Mar 2019 12:26:19 +0100
Subject: [PATCH] sandbox: table_print prints function signatures instead of
pointers
This does not work with C functions etc. but it seems that we do not
expose them directly in Lua interface for users.
---
daemon/lua/sandbox.lua.in | 50 +++++++++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 2 deletions(-)
diff --git a/daemon/lua/sandbox.lua.in b/daemon/lua/sandbox.lua.in
index 0d27f5477..14ada7f64 100644
--- a/daemon/lua/sandbox.lua.in
+++ b/daemon/lua/sandbox.lua.in
@@ -354,6 +354,44 @@ function eval_cmd(line, raw)
end
-- Pretty printing
+
+local function funcsign(f)
+-- thanks to AnandA777 from StackOverflow! Function funcsign is adapted version of
+-- https://stackoverflow.com/questions/51095022/inspect-function-signature-in-lua-5-1
+ assert(type(f) == 'function', "bad argument #1 to 'funcsign' (function expected)")
+ local func_args = {}
+ pcall(function()
+ local oldhook
+ local delay = 2
+ local function hook(event, line)
+ delay = delay - 1
+ if delay == 0 then -- call this only for the introspected function
+ for i = 1, math.huge do
+ -- stack depth 2 is the introspected function
+ local k, v = debug.getlocal(2, i)
+ if (k or '('):sub(1, 1) == '(' then
+ break -- internal variable, skip
+ else
+ table.insert(func_args, k)
+ end
+ end
+ if debug.getlocal(2, -1) then
+ -- vararg function
+ table.insert(func_args, "...")
+ end
+ debug.sethook(oldhook)
+ error('aborting the call to introspected function')
+ end
+ end
+ oldhook = debug.sethook(hook, "c") -- invoke hook() on function call
+ -- fake arguments, necessary to detect vararg functions
+ fakearg = {}
+ for j = 1, 64 do fakearg[#fakearg + 1] = true end
+ f(unpack(fakearg)) -- huh?
+ end)
+ return "(" .. table.concat(func_args, ", ") .. ")"
+end
+
function table_print (tt, indent, done)
done = done or {}
indent = indent or 0
@@ -394,13 +432,21 @@ function table_print (tt, indent, done)
result = result .. table_print (value, indent + 4, done)
result = result .. string.rep (" ", indent)
result = result .. "}\n"
+ elseif type (value) == "function" then
+ result = result .. string.format("[%s] => function %s%s\n",
+ tostring(key), tostring(key), funcsign(value))
else
result = result .. string.format("[%s] => %s\n",
tostring (key), printable(value))
end
end
- else
- result = result .. tostring(tt) .. "\n"
+ else -- not a table
+ if type(tt) == "function" then
+ tt_str = string.format("function%s\n", funcsign(tt))
+ else
+ tt_str = tostring(tt)
+ end
+ result = result .. tt_str .. "\n"
end
return result
end
--
GitLab