No more LUA_ERRGCMM errors

Errors in finalizers (__gc metamethods) are never propagated.
Instead, they generate a warning.

testes/all.lua

@@ -190,12 +190,17 @@ assert(dofile('verybig.lua', true) == 10); collectgarbage()
 dofile('files.lua')
 
 if #msgs > 0 then
-  warn("*tests not performed:\n  ")
+  warn("#tests not performed:\n  ")
   for i=1,#msgs do
     warn(msgs[i]); warn("\n  ")
   end
+  warn("\n")
 end
 
+print("(there should be two warnings now)")
+warn("#This is "); warn("an expected"); warn(" warning\n")
+warn("#This is"); warn(" another one\n")
+
 -- no test module should define 'debug'
 assert(debug == nil)
 
@@ -219,10 +224,6 @@ local _G, showmem, print, format, clock, time, difftime, assert, open =
 local fname = T and "time-debug.txt" or "time.txt"
 local lasttime
 
-
-warn("*This is "); warn("an expected"); warn(" warning\n")
-warn("*This is"); warn(" another one\n")
-
 if not usertests then
   -- open file with time of last performed test
   local f = io.open(fname)

testes/api.lua

@@ -114,13 +114,12 @@ end
 
 -- testing warnings
 T.testC([[
-  warning "*This "
-  warning "warning "
-  warning "should be in a"
-  warning " single line
+  warning "#This shold be a"
+  warning " single "
+  warning "warning
 "
-  warning "*This should be "
-  warning "another warning
+  warning "#This should be "
+  warning "another one
 "
 ]])
 
@@ -896,24 +895,15 @@ do   -- testing errors during GC
     a[i] = T.newuserdata(i)   -- creates several udata
   end
   for i=1,20,2 do   -- mark half of them to raise errors during GC
-    debug.setmetatable(a[i], {__gc = function (x) error("error inside gc") end})
+    debug.setmetatable(a[i],
+      {__gc = function (x) error("@expected error in gc") end})
   end
   for i=2,20,2 do   -- mark the other half to count and to create more garbage
     debug.setmetatable(a[i], {__gc = function (x) load("A=A+1")() end})
   end
+  a = nil
   _G.A = 0
-  a = 0
-  while 1 do
-    local stat, msg = pcall(collectgarbage)
-    if stat then
-      break   -- stop when no more errors
-    else
-      a = a + 1
-      assert(string.find(msg, "__gc"))
-    end
-  end
-  assert(a == 10)  -- number of errors
-
+  collectgarbage()
   assert(A == 10)  -- number of normal collections
   collectgarbage("restart")
 end

testes/gc.lua

@@ -353,40 +353,36 @@ GC()
 
 
 -- testing errors during GC
-do
-collectgarbage("stop")   -- stop collection
-local u = {}
-local s = {}; setmetatable(s, {__mode = 'k'})
-setmetatable(u, {__gc = function (o)
-  local i = s[o]
-  s[i] = true
-  assert(not s[i - 1])   -- check proper finalization order
-  if i == 8 then error("here") end   -- error during GC
-end})
+if T then
+  collectgarbage("stop")   -- stop collection
+  local u = {}
+  local s = {}; setmetatable(s, {__mode = 'k'})
+  setmetatable(u, {__gc = function (o)
+    local i = s[o]
+    s[i] = true
+    assert(not s[i - 1])   -- check proper finalization order
+    if i == 8 then error("@expected@") end   -- error during GC
+  end})
 
-for i = 6, 10 do
-  local n = setmetatable({}, getmetatable(u))
-  s[n] = i
-end
+  for i = 6, 10 do
+    local n = setmetatable({}, getmetatable(u))
+    s[n] = i
+  end
 
-assert(not pcall(collectgarbage))
-for i = 8, 10 do assert(s[i]) end
+  collectgarbage()
+  assert(string.find(_WARN, "error in __gc metamethod"))
+  assert(string.match(_WARN, "@(.-)@") == "expected")
+  for i = 8, 10 do assert(s[i]) end
 
-for i = 1, 5 do
-  local n = setmetatable({}, getmetatable(u))
-  s[n] = i
-end
+  for i = 1, 5 do
+    local n = setmetatable({}, getmetatable(u))
+    s[n] = i
+  end
 
-collectgarbage()
-for i = 1, 10 do assert(s[i]) end
+  collectgarbage()
+  for i = 1, 10 do assert(s[i]) end
 
-getmetatable(u).__gc = false
-
-
--- __gc errors with non-string messages
-setmetatable({}, {__gc = function () error{} end})
-local a, b = pcall(collectgarbage)
-assert(not a and type(b) == "string" and string.find(b, "error in __gc"))
+  getmetatable(u).__gc = false
 
 end
 print '+'
@@ -478,9 +474,11 @@ end
 
 
 -- errors during collection
-u = setmetatable({}, {__gc = function () error "!!!" end})
-u = nil
-assert(not pcall(collectgarbage))
+if T then
+  u = setmetatable({}, {__gc = function () error "@expected error" end})
+  u = nil
+  collectgarbage()
+end
 
 
 if not _soft then
@@ -645,11 +643,26 @@ do
 end
 
 -- create several objects to raise errors when collected while closing state
-do
-  local mt = {__gc = function (o) return o + 1 end}
-  for i = 1,10 do
+if T then
+  local error, assert, warn, find = error, assert, warn, string.find
+  local n = 0
+  local lastmsg
+  local mt = {__gc = function (o)
+    n = n + 1
+    assert(n == o[1])
+    if n == 1 then
+      _WARN = nil
+    elseif n == 2 then
+      assert(find(_WARN, "@expected warning"))
+      lastmsg = _WARN    -- get message from previous error (first 'o')
+    else
+      assert(lastmsg == _WARN)  -- subsequent error messages are equal
+    end
+    error"@expected warning"
+  end}
+  for i = 10, 1, -1 do
     -- create object and preserve it until the end
-    table.insert(___Glob, setmetatable({}, mt))
+    table.insert(___Glob, setmetatable({i}, mt))
   end
 end