Add stage 06: Lua bootstrap

The goal of stage 06 is to try parse zig synax in lua. I pulled in
lpeglable 1.2.0 and parser-gen off github to get started. All of this
needs to be cleaned up rather soon.

Lua boostraps using tcc and musl from the previous stage. Since musl
0.6.0 doesn't support dynamic linking this build of lua doesn't support
shared libraries. I couldn't easily patch musl with dlopen and friends
so instead I link statically and call deps with c api.

06/parser-gen/parsers/lua-5.3.4-tests/closure.lua

@@ -0,0 +1,247 @@
+-- $Id: closure.lua,v 1.59 2016/11/07 13:11:28 roberto Exp $
+-- See Copyright Notice in file all.lua
+
+print "testing closures"
+
+local A,B = 0,{g=10}
+function f(x)
+  local a = {}
+  for i=1,1000 do
+    local y = 0
+    do
+      a[i] = function () B.g = B.g+1; y = y+x; return y+A end
+    end
+  end
+  local dummy = function () return a[A] end
+  collectgarbage()
+  A = 1; assert(dummy() == a[1]); A = 0;
+  assert(a[1]() == x)
+  assert(a[3]() == x)
+  collectgarbage()
+  assert(B.g == 12)
+  return a
+end
+
+local a = f(10)
+-- force a GC in this level
+local x = {[1] = {}}   -- to detect a GC
+setmetatable(x, {__mode = 'kv'})
+while x[1] do   -- repeat until GC
+  local a = A..A..A..A  -- create garbage
+  A = A+1
+end
+assert(a[1]() == 20+A)
+assert(a[1]() == 30+A)
+assert(a[2]() == 10+A)
+collectgarbage()
+assert(a[2]() == 20+A)
+assert(a[2]() == 30+A)
+assert(a[3]() == 20+A)
+assert(a[8]() == 10+A)
+assert(getmetatable(x).__mode == 'kv')
+assert(B.g == 19)
+
+
+-- testing equality
+a = {}
+for i = 1, 5 do  a[i] = function (x) return x + a + _ENV end  end
+assert(a[3] == a[4] and a[4] == a[5])
+
+for i = 1, 5 do  a[i] = function (x) return i + a + _ENV end  end
+assert(a[3] ~= a[4] and a[4] ~= a[5])
+
+local function f()
+  return function (x)  return math.sin(_ENV[x])  end
+end
+assert(f() == f())
+
+
+-- testing closures with 'for' control variable
+a = {}
+for i=1,10 do
+  a[i] = {set = function(x) i=x end, get = function () return i end}
+  if i == 3 then break end
+end
+assert(a[4] == nil)
+a[1].set(10)
+assert(a[2].get() == 2)
+a[2].set('a')
+assert(a[3].get() == 3)
+assert(a[2].get() == 'a')
+
+a = {}
+local t = {"a", "b"}
+for i = 1, #t do
+  local k = t[i]
+  a[i] = {set = function(x, y) i=x; k=y end,
+          get = function () return i, k end}
+  if i == 2 then break end
+end
+a[1].set(10, 20)
+local r,s = a[2].get()
+assert(r == 2 and s == 'b')
+r,s = a[1].get()
+assert(r == 10 and s == 20)
+a[2].set('a', 'b')
+r,s = a[2].get()
+assert(r == "a" and s == "b")
+
+
+-- testing closures with 'for' control variable x break
+for i=1,3 do
+  f = function () return i end
+  break
+end
+assert(f() == 1)
+
+for k = 1, #t do
+  local v = t[k]
+  f = function () return k, v end
+  break
+end
+assert(({f()})[1] == 1)
+assert(({f()})[2] == "a")
+
+
+-- testing closure x break x return x errors
+
+local b
+function f(x)
+  local first = 1
+  while 1 do
+    if x == 3 and not first then return end
+    local a = 'xuxu'
+    b = function (op, y)
+          if op == 'set' then
+            a = x+y
+          else
+            return a
+          end
+        end
+    if x == 1 then do break end
+    elseif x == 2 then return
+    else if x ~= 3 then error() end
+    end
+    first = nil
+  end
+end
+
+for i=1,3 do
+  f(i)
+  assert(b('get') == 'xuxu')
+  b('set', 10); assert(b('get') == 10+i)
+  b = nil
+end
+
+pcall(f, 4);
+assert(b('get') == 'xuxu')
+b('set', 10); assert(b('get') == 14)
+
+
+local w
+-- testing multi-level closure
+function f(x)
+  return function (y)
+    return function (z) return w+x+y+z end
+  end
+end
+
+y = f(10)
+w = 1.345
+assert(y(20)(30) == 60+w)
+
+-- testing closures x repeat-until
+
+local a = {}
+local i = 1
+repeat
+  local x = i
+  a[i] = function () i = x+1; return x end
+until i > 10 or a[i]() ~= x
+assert(i == 11 and a[1]() == 1 and a[3]() == 3 and i == 4)
+
+
+-- testing closures created in 'then' and 'else' parts of 'if's
+a = {}
+for i = 1, 10 do
+  if i % 3 == 0 then
+    local y = 0
+    a[i] = function (x) local t = y; y = x; return t end
+  elseif i % 3 == 1 then
+    goto L1
+    error'not here'
+  ::L1::
+    local y = 1
+    a[i] = function (x) local t = y; y = x; return t end
+  elseif i % 3 == 2 then
+    local t
+    goto l4
+    ::l4a:: a[i] = t; goto l4b
+    error("should never be here!")
+    ::l4::
+    local y = 2
+    t = function (x) local t = y; y = x; return t end
+    goto l4a
+    error("should never be here!")
+    ::l4b::
+  end
+end
+
+for i = 1, 10 do
+  assert(a[i](i * 10) == i % 3 and a[i]() == i * 10)
+end
+
+print'+'
+
+
+-- test for correctly closing upvalues in tail calls of vararg functions
+local function t ()
+  local function c(a,b) assert(a=="test" and b=="OK") end
+  local function v(f, ...) c("test", f() ~= 1 and "FAILED" or "OK") end
+  local x = 1
+  return v(function() return x end)
+end
+t()
+
+
+-- test for debug manipulation of upvalues
+local debug = require'debug'
+
+do
+  local a , b, c = 3, 5, 7
+  foo1 = function () return a+b end;
+  foo2 = function () return b+a end;
+  do
+    local a = 10
+    foo3 = function () return a+b end;
+  end
+end
+
+assert(debug.upvalueid(foo1, 1))
+assert(debug.upvalueid(foo1, 2))
+assert(not pcall(debug.upvalueid, foo1, 3))
+assert(debug.upvalueid(foo1, 1) == debug.upvalueid(foo2, 2))
+assert(debug.upvalueid(foo1, 2) == debug.upvalueid(foo2, 1))
+assert(debug.upvalueid(foo3, 1))
+assert(debug.upvalueid(foo1, 1) ~= debug.upvalueid(foo3, 1))
+assert(debug.upvalueid(foo1, 2) == debug.upvalueid(foo3, 2))
+
+assert(debug.upvalueid(string.gmatch("x", "x"), 1) ~= nil)
+
+assert(foo1() == 3 + 5 and foo2() == 5 + 3)
+debug.upvaluejoin(foo1, 2, foo2, 2)
+assert(foo1() == 3 + 3 and foo2() == 5 + 3)
+assert(foo3() == 10 + 5)
+debug.upvaluejoin(foo3, 2, foo2, 1)
+assert(foo3() == 10 + 5)
+debug.upvaluejoin(foo3, 2, foo2, 2)
+assert(foo3() == 10 + 3)
+
+assert(not pcall(debug.upvaluejoin, foo1, 3, foo2, 1))
+assert(not pcall(debug.upvaluejoin, foo1, 1, foo2, 3))
+assert(not pcall(debug.upvaluejoin, foo1, 0, foo2, 1))
+assert(not pcall(debug.upvaluejoin, print, 1, foo2, 1))
+assert(not pcall(debug.upvaluejoin, {}, 1, foo2, 1))
+assert(not pcall(debug.upvaluejoin, foo1, 1, print, 1))
+
+print'OK'