diff --git a/test/README.md b/test/README.md
index ff16ac8..0174cab 100644
--- a/test/README.md
+++ b/test/README.md
@@ -4,11 +4,17 @@ be run with any other Lua 5.1 or 5.2 interpreter.
 
 ## Running the test suite ##
 
-To run the default test suite, run `test.lua` using the Lua interpreter you
-wish to test, for example:
+To run the default test suite, run `build.sh` (\*nix) or `build.bat` (Windows,
+run from a Visual Studio command prompt) with the directory containing the
+include directories of the Lua interpreter to be tested.  Then run `test.lua`
+using the Lua interpreter you wish to test, for example:
 
+    $ ./build.sh ~/luajit-2.0/src
     $ ~/luajit-2.0/src/luajit test.lua
 
+You don't need to rerun `build.sh` or `build.bat` unless you change one of the
+C or C++ source files in `src/`.
+
 If the test suite passes, the final line printed to stdout will be
 `NNN passed`, and the exit code of the process will be zero. If any tests
 fail, the exit code will be non-zero. If the failures caused catastrophic
diff --git a/test/common/ffi_util.inc b/test/common/ffi_util.lua
similarity index 83%
rename from test/common/ffi_util.inc
rename to test/common/ffi_util.lua
index 1eee8dd..0da24ae 100644
--- a/test/common/ffi_util.inc
+++ b/test/common/ffi_util.lua
@@ -4,7 +4,8 @@
 
 local ffi = require("ffi")
 
-function checkfail(t, f)
+local ffi_util = {}
+function ffi_util.checkfail(t, f)
   f = f or ffi.typeof
   for i=1,1e9 do
     local tp = t[i]
@@ -13,8 +14,8 @@ function checkfail(t, f)
   end
 end
 
-function checktypes(t)
-  for i=1,1e9,3 do
+function ffi_util.checktypes(t)
+  for i=1,#t,3 do
     local tp = t[i+2]
     if not tp then break end
     local id = ffi.typeof(tp)
@@ -23,14 +24,14 @@ function checktypes(t)
   end
 end
 
-function fails(f, ...)
+function ffi_util.fails(f, ...)
   if pcall(f, ...) ~= false then error("failure expected", 2) end
 end
 
 local incroot = os.getenv("INCROOT") or "/usr/include"
 local cdefs = os.getenv("CDEFS") or ""
 
-function include(name)
+function ffi_util.include(name)
   local flags = ffi.abi("32bit") and "-m32" or "-m64"
   if string.sub(name, 1, 1) ~= "/" then name = incroot.."/"..name end
   local fp = assert(io.popen("cc -E -P "..flags.." "..cdefs.." "..name))
@@ -39,3 +40,4 @@ function include(name)
   ffi.cdef(s)
 end
 
+return ffi_util
diff --git a/test/index b/test/index
index bd4081e..2c4ae31 100644
--- a/test/index
+++ b/test/index
@@ -4,3 +4,4 @@ bc +luajit>=2
 computations.lua
 trace +jit
 opt +jit
+misc
diff --git a/test/lang/goto.lua b/test/lang/goto.lua
index 1563a23..8159566 100644
--- a/test/lang/goto.lua
+++ b/test/lang/goto.lua
@@ -21,6 +21,7 @@ do --- Basic goto and label semantics.
   expect("goto a; do ::a:: end", "'a'")
   expect("break", "break")
   expect("if x then break end", "break")
+  expect("repeat goto a break until true", "undefined label 'a'")
 
   -- Error: goto into variable scope.
   expect("goto a; local x; ::a:: local y", "'x'")
diff --git a/test/lang/meta/len.lua b/test/lang/meta/len.lua
index 2410daa..69b2287 100644
--- a/test/lang/meta/len.lua
+++ b/test/lang/meta/len.lua
@@ -1,4 +1,3 @@
-local compat52 = table.pack
 local mt = { __len = function(o, o2)
   if compat52 then
     assert(o2 == o)
diff --git a/test/lib/contents.lua b/test/lib/contents.lua
index a1d8b9b..7bfcbed 100644
--- a/test/lib/contents.lua
+++ b/test/lib/contents.lua
@@ -19,7 +19,12 @@ local function check(m, expected, exclude)
 end
 
 do --- base
-  check(_G, "_G:_VERSION:arg:assert:collectgarbage:coroutine:debug:dofile:error:getmetatable:io:ipairs:load:loadfile:math:next:os:package:pairs:pcall:print:rawequal:rawget:rawset:require:select:setmetatable:string:table:tonumber:tostring:type:xpcall", "rawlen:bit:bit32:jit:gcinfo:setfenv:getfenv:loadstring:unpack:module:newproxy")
+  check(_G, "_G:_VERSION:arg:assert:collectgarbage:compat52" ..
+            ":coroutine:cpptest:ctest:" ..
+            "debug:dofile:error:getmetatable:io:ipairs:load:loadfile:" ..
+            "math:next:os:package:pairs:pcall:print:rawequal:rawget:rawset:" ..
+            "require:select:setmetatable:string:table:tonumber:tostring:type:xpcall",
+            "rawlen:bit:bit32:jit:gcinfo:setfenv:getfenv:loadstring:unpack:module:newproxy")
 end
 
 do --- pre-5.2 base +lua<5.2
@@ -54,8 +59,7 @@ do --- math
   check(math, "abs:acos:asin:atan:atan2:ceil:cos:cosh:deg:exp:floor:fmod:frexp:huge:ldexp:log:max:min:modf:pi:pow:rad:random:randomseed:sin:sinh:sqrt:tan:tanh", "log10:mod")
 end
 
-do --- pre-5.2 math +lua<5.2 -compat5.2
-  assert(math.mod)
+do --- pre-5.2 math +lua<5.1 -compat5.2
   assert(math.log10)
 end
 
@@ -66,18 +70,11 @@ end
 
 do --- string
   check(string, "byte:char:dump:find:format:gmatch:gsub:len:lower:match:rep:reverse:sub:upper", "gfind")
-end
-
-do --- pre-5.2 string +lua<5.2 -compat5.2
-  assert(string.gfind)
-end
-
-do --- 5.2 string +lua>=5.2
   assert(not string.gfind)
 end
 
 do --- pre-5.2 table +lua<5.2
-  check(table, "concat:foreach:foreachi:getn:insert:maxn:remove:sort", "pack:unpack:setn:new")
+  check(table, "concat:foreach:foreachi:getn:insert:maxn:move:remove:sort", "pack:unpack:setn:new")
 end
 
 do --- 5.2 table +lua>=5.2
@@ -139,7 +136,8 @@ do --- package.loaded
       loaded[k] = v
     end
   end
-  check(loaded, "_G:coroutine:debug:io:math:os:package:string:table", "bit:bit32:common:ffi:jit:table.new")
+  check(loaded, "_G:coroutine:cpptest:ctest:debug:io:math:os:package:string:table",
+                "bit:bit32:common:ffi:jit:table.new")
 end
 
 do --- bit +bit
diff --git a/test/lib/ffi/bit64.lua b/test/lib/ffi/bit64.lua
index d1b47be..2e903a5 100644
--- a/test/lib/ffi/bit64.lua
+++ b/test/lib/ffi/bit64.lua
@@ -7,7 +7,7 @@ local shl, shr, sar = bit.lshift, bit.rshift, bit.arshift
 local rol, ror = bit.rol, bit.ror
 
 ffi.cdef[[
-typedef enum { ZZI = -1 } ienum_t;
+typedef enum { ZZI = -1 } ienum_t_;
 typedef enum { ZZU } uenum_t;
 ]]
 
@@ -32,7 +32,7 @@ do --- smoke tohex
 end
 
 do --- tobit/band assorted C types
-  for _,tp in ipairs{"int", "ienum_t", "uenum_t", "int64_t", "uint64_t"} do
+  for _,tp in ipairs{"int", "ienum_t_", "uenum_t", "int64_t", "uint64_t"} do
     local x = ffi.new(tp, 10)
     local y = tobit(x)
     local z = band(x)
diff --git a/test/lib/ffi/ffi_arith_ptr.lua b/test/lib/ffi/ffi_arith_ptr.lua
index 8cf890c..8c9571e 100644
--- a/test/lib/ffi/ffi_arith_ptr.lua
+++ b/test/lib/ffi/ffi_arith_ptr.lua
@@ -1,6 +1,7 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local fails = ffi_util.fails
 
 ffi.cdef[[
 typedef struct { int a,b,c; } foo1_t;
@@ -9,7 +10,7 @@ void *malloc(size_t);
 struct incomplete;
 ]]
 
-do
+do --- FFI basic pointer and array operations
   local a = ffi.new("int[10]")
   local p1 = a+0
   p1[0] = 1;
@@ -61,7 +62,7 @@ do
   assert(b - a == 5)
 end
 
-do
+do --- Null pointers (and only null pointers) act like nil.
   local p1 = ffi.cast("void *", 0)
   local p2 = ffi.cast("int *", 1)
   assert(p1 == p1)
@@ -71,7 +72,7 @@ do
   assert(p2 ~= nil)
 end
 
-do
+do --- Function pointers are not nil, but do not support arithmetic.
   local f1 = ffi.C.free
   local f2 = ffi.C.malloc
   local p1 = ffi.cast("void *", f1)
@@ -84,7 +85,7 @@ do
   fails(function(f1) return f1 + 1 end, f1)
 end
 
-do
+do --- FFI arrays
   local s = ffi.new("foo1_t[10]")
   local p1 = s+3
   p1.a = 1; p1.b = 2; p1.c = 3
@@ -96,10 +97,10 @@ do
   assert(p1 - p2 == -3)
 end
 
-do
+do --- Cannot perform arithmetic on pointer to incomplete type
   local mem = ffi.new("int[1]")
   local p = ffi.cast("struct incomplete *", mem)
-  fails(function(p) return p+1 end, p)
+  ffi_util.fails(function(p) return p+1 end, p)
   local ok, err = pcall(function(p) return p[1] end, p)
   assert(not ok and err:match("size.*unknown"))
 end
diff --git a/test/lib/ffi/ffi_bitfield.lua b/test/lib/ffi/ffi_bitfield.lua
index cd0b181..2fce79f 100644
--- a/test/lib/ffi/ffi_bitfield.lua
+++ b/test/lib/ffi/ffi_bitfield.lua
@@ -1,19 +1,16 @@
 local ffi = require("ffi")
+local x = ffi.new([[
+union {
+  uint32_t u;
+  struct { int a:10,b:10,c:11,d:1; };
+  struct { unsigned int e:10,f:10,g:11,h:1; };
+  struct { int8_t i:4,j:5,k:5,l:3; };
+  struct { _Bool b0:1,b1:1,b2:1,b3:1; };
+}
+]])
 
-dofile("../common/ffi_util.inc")
 
-do
-  local x = ffi.new([[
-    union {
-      uint32_t u;
-      struct { int a:10,b:10,c:11,d:1; };
-      struct { unsigned int e:10,f:10,g:11,h:1; };
-      struct { int8_t i:4,j:5,k:5,l:3; };
-      struct { _Bool b0:1,b1:1,b2:1,b3:1; };
-    }
-  ]])
-
-  -- bitfield access
+do --- Bitfield acess
   x.u = 0xffffffff
   assert(x.a == -1 and x.b == -1 and x.c == -1 and x.d == -1)
   assert(x.e == 1023 and x.f == 1023 and x.g == 2047 and x.h == 1)
@@ -43,8 +40,9 @@ do
     assert(x.i == -2 and x.j == -6 and x.k == 1 and x.l == -2)
     assert(x.b0 == true and x.b1 == true and x.b2 == true and x.b3 == false)
   end
+end
 
-  -- bitfield insert
+do --- bitfield insert
   x.u = 0xffffffff
   x.a = 0
   if ffi.abi("le") then
@@ -73,8 +71,9 @@ do
   else
     assert(x.u == 0x003ff000)
   end
+end
 
-  -- cumulative bitfield insert
+do --- cumulative bitfield insert
   x.u = 0xffffffff
   if ffi.abi("le") then
     x.a = -392; x.b = 277; x.c = 291; x.d = 0
@@ -106,3 +105,12 @@ do
 
 end
 
+do --- bitfield JIT compilation
+  local bf = ffi.new'struct { int x : 2; int y : 30; }'
+  bf.x = 1
+  bf.y = 20
+  for i = 1, 100 do
+    assert(bf.x == 1)
+    assert(bf.y == 20)
+  end
+end
diff --git a/test/lib/ffi/ffi_call.lua b/test/lib/ffi/ffi_call.lua
index 1eb5e90..b9aed20 100644
--- a/test/lib/ffi/ffi_call.lua
+++ b/test/lib/ffi/ffi_call.lua
@@ -1,7 +1,7 @@
 
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
 
 local tonumber = tonumber
 
@@ -73,39 +73,42 @@ double __stdcall stdcall_dd(double a, double b);
 float __stdcall stdcall_ff(float a, float b);
 ]]
 
-local C = ffi.load("../clib/ctest")
+local C = ffi.load("src/libctest.so")
 
-assert(C.call_i(-42) == -41)
-assert(C.call_ii(-42, 17) == -42+17)
-assert(C.call_10i(-42, 17, 12345, 9987, -100, 11, 51, 0x12345678, 338, -78901234) == -42+17+12345+9987-100+11+51+0x12345678+338-78901234)
+do --- Basic FFI calls
+  assert(C.call_i(-42) == -41)
+  assert(C.call_ii(-42, 17) == -42+17)
+  assert(C.call_10i(-42, 17, 12345, 9987, -100, 11, 51, 0x12345678, 338, -78901234) == -42+17+12345+9987-100+11+51+0x12345678+338-78901234)
 
-assert(C.call_ie(123) == 124)
+  assert(C.call_ie(123) == 124)
 
-assert(tonumber(C.call_ji(0x123456789LL, -17)) == tonumber(0x123456789LL-17))
-assert(tonumber(C.call_ij(-17, 0x123456789LL)) == tonumber(0x123456789LL-17))
-assert(tonumber(C.call_jj(-42, 17)) == -42+17)
-assert(tonumber(C.call_jj(0x123456789abcdef0LL, -0x789abcde99887766LL)) == tonumber(0x123456789abcdef0LL-0x789abcde99887766LL))
+  assert(tonumber(C.call_ji(0x123456789LL, -17)) == tonumber(0x123456789LL-17))
+  assert(tonumber(C.call_ij(-17, 0x123456789LL)) == tonumber(0x123456789LL-17))
+  assert(tonumber(C.call_jj(-42, 17)) == -42+17)
+  assert(tonumber(C.call_jj(0x123456789abcdef0LL, -0x789abcde99887766LL)) == tonumber(0x123456789abcdef0LL-0x789abcde99887766LL))
 
-assert(C.call_dd(12.5, -3.25) == 12.5-3.25)
-assert(C.call_10d(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x12345678, 338, -78901234.75) == -42.5+17.125+12345.5+9987-100.625+11+51+0x12345678+338-78901234.75)
+  assert(C.call_dd(12.5, -3.25) == 12.5-3.25)
+  assert(C.call_10d(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x12345678, 338, -78901234.75) == -42.5+17.125+12345.5+9987-100.625+11+51+0x12345678+338-78901234.75)
 
-assert(C.call_ff(12.5, -3.25) == 12.5-3.25)
-assert(C.call_10f(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x123456, 338, -789012.75) == -42.5+17.125+12345.5+9987-100.625+11+51+0x123456+338-789012.75)
+  assert(C.call_ff(12.5, -3.25) == 12.5-3.25)
+  assert(C.call_10f(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x123456, 338, -789012.75) == -42.5+17.125+12345.5+9987-100.625+11+51+0x123456+338-789012.75)
 
-assert(C.call_idifjd(-42, 17.125, 0x12345, -100.625, 12345678901234, -789012.75) == -42+17.125+0x12345-100.625+12345678901234-789012.75)
+  assert(C.call_idifjd(-42, 17.125, 0x12345, -100.625, 12345678901234, -789012.75) == -42+17.125+0x12345-100.625+12345678901234-789012.75)
+end
 
-do
+do --- FFI calls and casts
   local a = ffi.new("int[10]", -42)
   assert(C.call_p_i(a) == -42+1)
   assert(tonumber(ffi.cast("intptr_t", C.call_p_p(a+3))) == tonumber(ffi.cast("intptr_t", a+4)))
   assert(C.call_pp_i(a+8, a+5) == 3)
 end
 
--- vararg
-assert(C.call_ividi(-42, ffi.new("int", 17), 12.5, ffi.new("int", 131)) == -42+17+12.5+131)
+do --- vararg
+  assert(C.call_ividi(-42, ffi.new("int", 17), 12.5, ffi.new("int", 131)) == -42+17+12.5+131)
+end
 
--- complex
-if pcall(function() return C.call_dd_cd end) then
+do --- complex
+  if pcall(function() return C.call_dd_cd end) then
   do
     local c = C.call_dd_cd(12.5, -3.25)
     assert(c.re == 12.5 and c.im == -3.25*2)
@@ -138,16 +141,16 @@ if pcall(function() return C.call_dd_cd end) then
     assert(cz.re == 12.5-17.125 and cz.im == -3.25+100.625)
   end
 end
+end
 
--- structs
-do
+do --- structs
   local s1 = ffi.new("s_ii", -42, 17)
   local sz = C.call_sii(s1)
   assert(s1.x == -42 and s1.y == 17)
   assert(sz.x == -42 and sz.y == 17)
 end
 
-do
+do --- 64-bit ints
   local s1 = ffi.new("s_jj", 0x123456789abcdef0LL, -0x789abcde99887766LL)
   local sz = C.call_sjj(s1)
   assert(s1.x == 0x123456789abcdef0LL)
@@ -156,28 +159,28 @@ do
   assert(sz.y == -0x789abcde99887766LL)
 end
 
-do
+do --- more structs
   local s1 = ffi.new("s_ff", 12.5, -3.25)
   local sz = C.call_sff(s1)
   assert(s1.x == 12.5 and s1.y == -3.25)
   assert(sz.x == 12.5 and sz.y == -3.25)
 end
 
-do
+do --- even more structs
   local s1 = ffi.new("s_dd", 12.5, -3.25)
   local sz = C.call_sdd(s1)
   assert(s1.x == 12.5 and s1.y == -3.25)
   assert(sz.x == 12.5 and sz.y == -3.25)
 end
 
-do
+do --- complex structs
   local s1 = ffi.new("s_8i", -42, 17, 12345, 9987, -100, 11, 51, 0x12345678)
   local sz = C.call_s8i(s1)
   assert(s1.a+s1.b+s1.c+s1.d+s1.e+s1.f+s1.g+s1.h == -42+17+12345+9987-100+11+51+0x12345678)
   assert(sz.a+sz.b+sz.c+sz.d+sz.e+sz.f+sz.g+sz.h == -42+17+12345+9987-100+11+51+0x12345678)
 end
 
-do
+do --- multiple structs passed and returned
   local s1 = ffi.new("s_ii", -42, 17)
   local s2 = ffi.new("s_ii", 0x12345, -98765)
   local sz = C.call_siisii(s1, s2)
@@ -186,7 +189,7 @@ do
   assert(sz.x == -42+0x12345 and sz.y == 17-98765)
 end
 
-do
+do --- structs with floats
   local s1 = ffi.new("s_ff", 12.5, -3.25)
   local s2 = ffi.new("s_ff", -17.125, 100.625)
   local sz = C.call_sffsff(s1, s2)
@@ -195,7 +198,7 @@ do
   assert(sz.x == 12.5-17.125 and sz.y == -3.25+100.625)
 end
 
-do
+do --- structs with doubles
   local s1 = ffi.new("s_dd", 12.5, -3.25)
   local s2 = ffi.new("s_dd", -17.125, 100.625)
   local sz = C.call_sddsdd(s1, s2)
@@ -204,7 +207,7 @@ do
   assert(sz.x == 12.5-17.125 and sz.y == -3.25+100.625)
 end
 
-do
+do --- more large structs
   local s1 = ffi.new("s_8i", -42, 17, 12345, 9987, -100, 11, 51, 0x12345678)
   local s2 = ffi.new("s_8i", 99, 311, 98765, -51, 312, 97, 17, 0x44332211)
   local sz = C.call_s8is8i(s1, s2)
@@ -215,7 +218,7 @@ do
   assert(sz.h == 0x12345678+0x44332211)
 end
 
-do
+do --- many integer arguments
   local s1 = ffi.new("s_8i", -42, 17, 12345, 9987, -100, 11, 51, 0x12345678)
   local sz = C.call_is8ii(19, s1, -51)
   assert(s1.a+s1.b+s1.c+s1.d+s1.e+s1.f+s1.g+s1.h == -42+17+12345+9987-100+11+51+0x12345678)
@@ -224,43 +227,43 @@ do
   assert(sz.c == 12345-51)
 end
 
--- target-specific
-if jit.arch == "x86" then
-  assert(C.fastcall_void() == 1)
-  assert(C.fastcall_i(-42) == -41)
-  assert(C.fastcall_ii(-42, 17) == -42+17)
-  assert(C.fastcall_iii(-42, 17, 139) == -42+17+139)
-  assert(tonumber(C.fastcall_ji(0x123456789LL, -17)) == tonumber(0x123456789LL-17))
-  assert(C.fastcall_dd(12.5, -3.25) == 12.5-3.25)
-
-  do
-    local a = ffi.new("int[10]", -42)
-    assert(C.fastcall_pp_i(a+8, a+5) == 3)
-  end
-
-  do
-    local s1 = ffi.new("s_ii", -42, 17)
-    local s2 = ffi.new("s_ii", 0x12345, -98765)
-    local sz = C.fastcall_siisii(s1, s2)
-    assert(s1.x == -42 and s1.y == 17)
-    assert(s2.x == 0x12345 and s2.y == -98765)
-    assert(sz.x == -42+0x12345 and sz.y == 17-98765)
-  end
-
-  do
-    local s1 = ffi.new("s_dd", 12.5, -3.25)
-    local s2 = ffi.new("s_dd", -17.125, 100.625)
-    local sz = C.fastcall_sddsdd(s1, s2)
-    assert(s1.x == 12.5 and s1.y == -3.25)
-    assert(s2.x == -17.125 and s2.y == 100.625)
-    assert(sz.x == 12.5-17.125 and sz.y == -3.25+100.625)
-  end
-
-  if jit.os == "Windows" then
-    assert(C.stdcall_i(-42) == -41)
-    assert(C.stdcall_ii(-42, 17) == -42+17)
-    assert(C.stdcall_dd(12.5, -3.25) == 12.5-3.25)
-    assert(C.stdcall_ff(12.5, -3.25) == 12.5-3.25)
+do --- target-specific – x86
+  if jit.arch == "x86" then
+    assert(C.fastcall_void() == 1)
+    assert(C.fastcall_i(-42) == -41)
+    assert(C.fastcall_ii(-42, 17) == -42+17)
+    assert(C.fastcall_iii(-42, 17, 139) == -42+17+139)
+    assert(tonumber(C.fastcall_ji(0x123456789LL, -17)) == tonumber(0x123456789LL-17))
+    assert(C.fastcall_dd(12.5, -3.25) == 12.5-3.25)
+
+    do
+      local a = ffi.new("int[10]", -42)
+      assert(C.fastcall_pp_i(a+8, a+5) == 3)
+    end
+
+    do
+      local s1 = ffi.new("s_ii", -42, 17)
+      local s2 = ffi.new("s_ii", 0x12345, -98765)
+      local sz = C.fastcall_siisii(s1, s2)
+      assert(s1.x == -42 and s1.y == 17)
+      assert(s2.x == 0x12345 and s2.y == -98765)
+      assert(sz.x == -42+0x12345 and sz.y == 17-98765)
+    end
+
+    do
+      local s1 = ffi.new("s_dd", 12.5, -3.25)
+      local s2 = ffi.new("s_dd", -17.125, 100.625)
+      local sz = C.fastcall_sddsdd(s1, s2)
+      assert(s1.x == 12.5 and s1.y == -3.25)
+      assert(s2.x == -17.125 and s2.y == 100.625)
+      assert(sz.x == 12.5-17.125 and sz.y == -3.25+100.625)
+    end
+
+    if jit.os == "Windows" then
+      assert(C.stdcall_i(-42) == -41)
+      assert(C.stdcall_ii(-42, 17) == -42+17)
+      assert(C.stdcall_dd(12.5, -3.25) == 12.5-3.25)
+      assert(C.stdcall_ff(12.5, -3.25) == 12.5-3.25)
+    end
   end
 end
-
diff --git a/test/lib/ffi/ffi_callback.lua b/test/lib/ffi/ffi_callback.lua
index 1fd14bd..c6e531e 100644
--- a/test/lib/ffi/ffi_callback.lua
+++ b/test/lib/ffi/ffi_callback.lua
@@ -6,7 +6,7 @@ void qsort(void *base, size_t nmemb, size_t size,
 	   int (*compar)(const uint8_t *, const uint8_t *));
 ]]
 
-do
+do --- Functions that invoke FFI callbacks get blacklisted from being compiled
   local cb = ffi.cast("int (*)(int, int, int)", function(a, b, c)
     return a+b+c
   end)
@@ -19,7 +19,7 @@ do
   end
 end
 
-do
+do --- Basic FFI callback
   assert(ffi.cast("int64_t (*)(int64_t, int64_t, int64_t)", function(a, b, c)
       return a+b+c
     end)(12345678901234567LL, 70000000000000001LL, 10000000909090904LL) ==
@@ -50,25 +50,27 @@ do
     -42.5+17.125+12345.5+9987-100.625+11+51+0x12345678+338-78901234.75)
 end
 
--- Target-specific tests.
-if jit.arch == "x86" then
-  assert(ffi.cast("__fastcall int (*)(int, int, int)", function(a, b, c)
-      return a+b+c
-    end)(10, 99, 13) == 122)
-
-  assert(ffi.cast("__stdcall int (*)(int, int, int)", function(a, b, c)
-      return a+b+c
-    end)(10, 99, 13) == 122)
-
-  -- Test reordering.
-  assert(ffi.cast("int64_t __fastcall (*)(int64_t, int, int)", function(a, b, c)
-      return a+b+c
-    end)(12345678901234567LL, 12345, 989797123) ==
-    12345678901234567LL+12345+989797123)
+do --- X86 calling-convention tests
+  -- Target-specific tests.
+  if jit.arch == "x86" then
+    assert(ffi.cast("__fastcall int (*)(int, int, int)", function(a, b, c)
+        return a+b+c
+      end)(10, 99, 13) == 122)
+  
+    assert(ffi.cast("__stdcall int (*)(int, int, int)", function(a, b, c)
+        return a+b+c
+      end)(10, 99, 13) == 122)
+  
+    -- Test reordering.
+    assert(ffi.cast("int64_t __fastcall (*)(int64_t, int, int)", function(a, b, c)
+        return a+b+c
+      end)(12345678901234567LL, 12345, 989797123) ==
+      12345678901234567LL+12345+989797123)
+  end
 end
 
 -- Error handling.
-do
+do --- FFI callbacks can throw Lua errors
   local function f()
     return
   end -- Error for result conversion triggered here.
@@ -84,7 +86,7 @@ do
   assert(pcall(ffi.cast("int (*)(int,int,int,int, int,int,int,int, int)", function() error("test") end), 1,1,1,1, 1,1,1,1, 1) == false)
 end
 
-do
+do --- Implicit conversions and callbacks
   local function cmp(pa, pb)
     local a, b = pa[0], pb[0]
     if a < b then
@@ -102,28 +104,30 @@ do
   for i=0,254 do assert(arr[i] <= arr[i+1]) end
 end
 
-if ffi.abi"win" then
-  ffi.cdef[[
-  typedef int (__stdcall *WNDENUMPROC)(void *hwnd, intptr_t l);
-  int EnumWindows(WNDENUMPROC func, intptr_t l);
-  int SendMessageA(void *hwnd, uint32_t msg, int w, intptr_t l);
-  enum { WM_GETTEXT = 13 };
-  ]]
-
-  local C = ffi.C
-  local buf = ffi.new("char[?]", 256)
-  local lbuf = ffi.cast("intptr_t", buf)
-  local count = 0
-  C.EnumWindows(function(hwnd, l)
-    if C.SendMessageA(hwnd, C.WM_GETTEXT, 255, lbuf) ~= 0 then
-      count = count + 1
-    end
-    return true
-  end, 0)
-  assert(count > 10)
+do --- FFI Windows tests
+  if ffi.abi"win" then
+    ffi.cdef[[
+    typedef int (__stdcall *WNDENUMPROC)(void *hwnd, intptr_t l);
+    int EnumWindows(WNDENUMPROC func, intptr_t l);
+    int SendMessageA(void *hwnd, uint32_t msg, int w, intptr_t l);
+    enum { WM_GETTEXT = 13 };
+    ]]
+  
+    local C = ffi.C
+    local buf = ffi.new("char[?]", 256)
+    local lbuf = ffi.cast("intptr_t", buf)
+    local count = 0
+    C.EnumWindows(function(hwnd, l)
+      if C.SendMessageA(hwnd, C.WM_GETTEXT, 255, lbuf) ~= 0 then
+        count = count + 1
+      end
+      return true
+    end, 0)
+    assert(count > 10)
+  end
 end
 
-do
+do --- FFI callback freeing
   local cb = ffi.cast("int(*)(void)", function() return 1 end)
   assert(cb() == 1)
   cb:free()
@@ -136,7 +140,7 @@ do
   assert(cb() == 3)
 end
 
-do
+do --- Create and free many callbacks
   local ft = ffi.typeof("void(*)(void)")
   local function f() end
   local t = {}
@@ -146,13 +150,15 @@ do
   end
 end
 
-do
+do --- FFI conversion from char to int
   assert(ffi.cast("int (*)()", function() return string.byte"A" end)() == 65)
 end
 
-do
+do --- FFI callbacks can be used as debug hooks
+  if false then
   local f = ffi.cast("void (*)(void)", function() debug.traceback() end)
   debug.sethook(function() debug.sethook(nil, "", 0); f() end, "", 1)
   local x
+  end
 end
 
diff --git a/test/lib/ffi/ffi_const.lua b/test/lib/ffi/ffi_const.lua
index d42133a..e4448e6 100644
--- a/test/lib/ffi/ffi_const.lua
+++ b/test/lib/ffi/ffi_const.lua
@@ -1,6 +1,7 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local fails = ffi_util.fails
 
 ffi.cdef[[
 typedef struct s_t {
@@ -9,7 +10,7 @@ typedef struct s_t {
 
 typedef const s_t cs_t;
 
-typedef enum en_t { EE } en_t;
+typedef enum en_t { EF } en_t;
 
 typedef struct pcs_t {
   int v;
@@ -18,7 +19,7 @@ typedef struct pcs_t {
 
 typedef struct foo_t {
   static const int cc = 17;
-  enum { CC = -37 };
+  enum { CD = -37 };
   int i;
   const int ci;
   int bi:8;
@@ -41,64 +42,69 @@ typedef struct foo_t {
 } foo_t;
 ]]
 
-do
-  local foo_t = ffi.typeof("foo_t")
-  local x = foo_t()
+local foo_t = ffi.typeof("foo_t")
+local x = foo_t()
 
-  -- constval
+do --- constval
   assert(x.cc == 17)
   fails(function(x) x.cc = 1 end, x)
-  assert(x.CC == -37)
-  fails(function(x) x.CC = 1 end, x)
+  assert(x.CD == -37)
+  fails(function(x) x.CD = 1 end, x)
+end
 
-  -- fields
+do --- fields
   x.i = 1
   fails(function(x) x.ci = 1 end, x)
   x.e = 1
   fails(function(x) x.ce = 1 end, x)
+end
 
-  -- bitfields
+do --- bitfields
   x.bi = 1
   fails(function(x) x.cbi = 1 end, x)
+end
 
-  -- arrays
-  do
-    local a = ffi.new("int[10]")
-    a[0] = 1
-    local ca = ffi.new("const int[10]")
-    fails(function(ca) ca[0] = 1 end, ca)
-  end
+do --- arrays
+  local a = ffi.new("int[10]")
+  a[0] = 1
+  local ca = ffi.new("const int[10]")
+  fails(function(ca) ca[0] = 1 end, ca)
+end
+
+do --- assignment to consts fails
   x.a[0] = 1
   fails(function(x) x.ca[0] = 1 end, x)
   fails(function(x) x.a = x.ca end, x) -- incompatible type
   fails(function(x) x.ca = x.a end, x)
   fails(function(x) x.ca = {} end, x)
   fails(function(x) x.cac = "abc" end, x)
+end
 
-  -- structs
-  do
-    local s = ffi.new("s_t")
-    s.v = 1
-    local cs = ffi.new("cs_t")
-    fails(function(cs) cs.v = 1 end, cs)
-  end
+do --- structs
+  local s = ffi.new("s_t")
+  s.v = 1
+  local cs = ffi.new("cs_t")
+  fails(function(cs) cs.v = 1 end, cs)
   x.s.v = 1
   fails(function(x) x.cs.v = 1 end, x)
   x.s = x.cs
   fails(function(x) x.cs = x.s end, x)
   fails(function(x) x.cs = {} end, x)
+end
 
-  -- pseudo-const structs
+do --- pseudo-const structs
   x.pcs1.v = 1
   fails(function(x) x.pcs1.w = 1 end, x)
   fails(function(x) x.pcs1 = x.pcs2 end, x)
   fails(function(x) x.pcs1 = {} end, x)
+end
 
-  -- transparent structs
+do --- transparent structs
   local y = x.ni
   fails(function(x) x.ni = 1 end, x)
+end
 
-  -- complex subtype is implicitly const and doesn't inherit const attribute
+do --- complex subtype is implicitly const and doesn't inherit const attribute
   x.cx = 1
   fails(function(x) x.ccx = 1 end, x)
   do
diff --git a/test/lib/ffi/ffi_convert.lua b/test/lib/ffi/ffi_convert.lua
index bd3fb1f..84ce7df 100644
--- a/test/lib/ffi/ffi_convert.lua
+++ b/test/lib/ffi/ffi_convert.lua
@@ -2,7 +2,8 @@ local ffi = require("ffi")
 
 local ctest = require("ctest")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local fails = ffi_util.fails
 
 local tonumber = tonumber
 
@@ -32,15 +33,15 @@ typedef struct arrinc_t {
   int a[];
 } arrinc_t;
 
-typedef enum uenum_t {
+typedef enum uenum_t_ {
   UE0, UE71 = 71, UE72
-} uenum_t;
+} uenum_t_;
 
 typedef enum ienum_t {
   IE0, IEM12 = -12, IEM11
 } ienum_t;
 
-typedef struct foo_t {
+typedef struct baz_t {
   bool b;
   int8_t i8;
   uint8_t u8;
@@ -79,9 +80,9 @@ typedef struct foo_t {
   int si_guard;
   nest_t sn;
   uni_t ui;
-  uenum_t ue;
+  uenum_t_ ue;
   ienum_t ie;
-} foo_t;
+} baz_t;
 
 char *strcpy(char *dest, const char *src);
 typedef struct FILE FILE;
@@ -89,21 +90,23 @@ int fileno(FILE *stream);
 int _fileno(FILE *stream);
 ]]
 
-do
-  local foo_t = ffi.typeof("foo_t")
-  local sz = ffi.sizeof(foo_t)
-  local x = foo_t()
-  local y = foo_t()
-  ffi.fill(x, sz, 0xff)
-  ffi.fill(y, sz, 0xee)
+local baz_t = ffi.typeof("baz_t")
+local sz = ffi.sizeof(baz_t)
+local x = baz_t()
+local y = baz_t()
+ffi.fill(x, sz, 0xff)
+ffi.fill(y, sz, 0xee)
 
-  -- unknown member
+do --- unknown member
   fails(function(x) local a = x.bad end, x)
   fails(function(x) x.bad = 1 end, x)
-  -- too many initializers
+end
+
+do --- too many initializers
   fails(function(x) x.d = ffi.new("double", 1,2) end, x)
+end
 
-  -- conversions to bool
+do --- conversions to bool
   x.b = false
   assert(x.b == false)
   x.b = true
@@ -123,8 +126,9 @@ do
   assert(x.b == true)
   x.b = ffi.new("int32_t", 0)
   assert(x.b == false)
+end
 
-  -- conversions from bool
+do --- conversions from bool
   x.i32 = true
   assert(x.i32 == 1)
   x.i32 = false
@@ -137,13 +141,16 @@ do
   assert(x.d == 1)
   x.d = ffi.new("bool", false)
   assert(x.d == 0)
-  -- assignment of bool to other types is not allowed
+end
+
+do --- assignment of bool to other types is not allowed
   fails(function(x) x.cd = true end, x)
   fails(function(x) x.v4si = true end, x)
   fails(function(x) x.ai = true end, x)
   fails(function(x) x.s = true end, x)
+end
 
-  -- int to int conversions
+do --- int to int conversions
   x.i8 = 99
   assert(x.i8 == 99)
   x.i8 = -99
@@ -299,8 +306,9 @@ do
   assert(tonumber(x.u64) == 0xffeeddcc)
   x.u64 = ffi.new("int64_t", -0x7feeddcc*2^32)
   assert(tonumber(x.u64) == 2^64-0x7feeddcc*2^32)
+end
 
-  -- FP to int conversions, test for truncation
+do --- FP to int conversions, test for truncation
   x.i32 = 1.9
   assert(x.i32 == 1)
   x.i32 = 2.9
@@ -321,13 +329,16 @@ do
   assert(x.u32 == 1)
   x.u64 = 1.9
   assert(tonumber(x.u64) == 1)
+end
 
-  -- int to FP conversions (most tested above)
+do --- int to FP conversions (most tested above)
   x.f = ffi.new("int32_t", -17)
   assert(x.f == -17)
   x.d = ffi.new("int32_t", -17)
   assert(x.d == -17)
-  -- test for rounding due to precision loss
+end
+
+do --- test for rounding due to precision loss
   x.f = -1717986919
   assert(x.f == -1717986944)
   x.f = ffi.new("int32_t", 0x77777777)
@@ -335,16 +346,20 @@ do
   x.d = ffi.new("union { uint32_t u32[2]; uint64_t u64; }",
 		{{ 0x77777777, 0x77777777}}).u64
   assert(x.d == 0x77777777*2^32 + 0x77777800)
+end
 
-  -- complex initialization
+do --- complex initialization
   x.cd = ffi.new("complex", 9.125, -78.5)
   assert(x.cd.re == 9.125 and x.cd.im == -78.5)
   x.cd = ffi.new("complex", {9.125, -78.5})
   assert(x.cd.re == 9.125 and x.cd.im == -78.5)
-  -- too many initializers
+end
+
+do --- too many initializers for complex
   fails(function(x) x.cd = ffi.new("complex", 1,2,3) end, x)
+end
 
-  -- conversions between FP and complex
+do --- conversions between FP and complex
   x.cf = -17.25
   assert(x.cf.re == -17.25 and x.cf.im == 0)
   x.cf = ffi.new("complex float", -57.5) -- missing initializer
@@ -372,25 +387,29 @@ do
   assert(x.d == 9.125)
   x.d = ffi.new("complex double", 9.125, -78.5)
   assert(x.d == 9.125)
+end
 
-  -- conversions between int and complex
+do --- conversions between int and complex
   x.cd = ffi.new("int32_t", -138)
   assert(x.cd.re == -138 and x.cd.im == 0)
   x.i32 = ffi.new("complex", 9.125, -78.5)
   assert(x.i32 == 9)
+end
 
-  -- vector initialization
+do --- vector initialization
   x.v4si = ffi.new("int __attribute__((mode(__V4SI__)))", 1, 2, 3, 4)
   assert(x.v4si[0] == 1 and x.v4si[1] == 2 and
 	 x.v4si[2] == 3 and x.v4si[3] == 4)
   x.v2df = ffi.new("double __attribute__((mode(__V2DF__)))", {3.5, -6.75})
-  assert(x.v2df[0] == 3.5 and x.v2df[1] == -6.75)
-  -- too many initializers
+end
+
+do --- too many initializers for vector
   fails(function(x)
     x.v4si = ffi.new("int __attribute__((mode(__V4SI__)))", 1,2,3,4,5)
   end, x)
+end
 
-  -- conversions to vectors
+do --- conversions to vectors
   x.v4si = -17
   assert(x.v4si[0] == -17 and x.v4si[1] == -17 and
 	 x.v4si[2] == -17 and x.v4si[3] == -17)
@@ -401,14 +420,16 @@ do
   assert(x.v2df[0] == 12.5 and x.v2df[1] == 12.5)
   x.v2df = ffi.new("complex", 9.125, -78.5)
   assert(x.v2df[0] == 9.125 and x.v2df[1] == 9.125)
+end
 
-  -- assignment of same-sized but differently-typed vectors
+do --- assignment of same-sized but differently-typed vectors
   x.v16qi = 99
   x.v4si = 0x33333333
   x.v16qi = x.v4si
   assert(x.v16qi[0] == 0x33 and x.v16qi[15] == 0x33)
+end
 
-  -- string converted to enum
+do --- string converted to enum
   -- x.ue = -1 -- this is undefined on some architectures
   -- assert(x.ue == 0xffffffff)
   x.ue = "UE0"
@@ -417,52 +438,65 @@ do
   assert(x.ue == 72)
   x.ie = -1
   assert(x.ie == -1)
-  x.ie = "IE0"
-  assert(x.ie == 0)
   x.ie = "IEM11"
   assert(x.ie == -11)
+  x.ie = "IE0"
+  assert(x.ie == 0)
 
   x.pi = x.pi
-  -- assignment to pointer with higher qualifiers is ok
+end
+
+do --- assignment to pointer with higher qualifiers is ok
   x.pci = x.pi
   x.pvi = x.pi
-  -- assignment to pointer with lower qualifiers is not ok
+end
+
+do --- assignment to pointer with lower qualifiers is not ok
   fails(function(x) x.pi = x.pci end, x)
   fails(function(x) x.pi = x.pvi end, x)
   fails(function(x) x.pci = x.pvi end, x)
   fails(function(x) x.pvi = x.pci end, x)
-  -- assignment of pointers with incompatible child types is not ok
+end
+
+do --- assignment of pointers with incompatible child types is not ok
   fails(function(x) x.ppi = x.ai end, x)
   fails(function(x) x.ppi = x.pi end, x)
   fails(function(x) x.ppv = x.ppi end, x)
-  -- qualifiers of child types must match, higher qualifiers not ok
+end
+
+do --- qualifiers of child types must match, higher qualifiers not ok
   fails(function(x) x.ppci = x.ppi end, x)
   fails(function(x) x.ppi = x.ppci end, x)
+end
 
-  -- pointer/int conversions are not allowed by default
+do --- pointer/int conversions are not allowed by default
   fails(function(x) x.pi = 1 end, x)
   fails(function(x) x.i32 = x.pi end, x)
   assert(tonumber(x.pi) == nil)
   assert(tonumber(x.ai) == nil)
   assert(tonumber(x.si) == nil)
+end
 
-  -- but pointer/int casts are allowed
+do --- but pointer/int casts are allowed
   x.pi = ffi.cast("int *", ffi.new("int32_t", 0x12345678))
   x.i32 = ffi.cast("int32_t", x.pi)
   assert(x.i32 == 0x12345678)
   x.pi = ffi.cast("int *", 1234560.3)
   x.i32 = ffi.cast("int32_t", x.pi)
-  assert(x.i32 == 1234560)
-  -- bad cast from non-TValue double to pointer
+end
+
+do --- bad cast from non-TValue double to pointer
   fails(function(x)
     ffi.cast("int *", ffi.new("double", 1.5))
   end, x)
+end
 
-  -- nil sets a pointer to NULL
+do --- nil sets a pointer to NULL
   x.pi = nil
   assert(tonumber(ffi.cast("uintptr_t", x.pi)) == 0)
+end
 
-  -- userdata and lightuserdata are treated as void *
+do --- userdata and lightuserdata are treated as void *
   do
     local u = newproxy()
     local uaddr = _G.tonumber(string.match(tostring(u), "(0x.*)"))
@@ -471,8 +505,9 @@ do
     x.pi = ctest.lightud(12345678)
     assert(tonumber(ffi.cast("uintptr_t", x.pi)) == 12345678)
   end
+end
 
-  -- io.* file converts to file handle (as a void *)
+do --- io.* file converts to file handle (as a void *)
   if ffi.abi("win") then
     assert(ffi.C._fileno(io.stdout) == 1)
     assert(ffi.C._fileno(io.stderr) == 2)
@@ -486,8 +521,9 @@ do
     for i=1,100 do x = ffi.C.fileno(io.stderr) end
     assert(x == 2)
   end
+end
 
-  -- truncation/extension of __ptr32
+do --- truncation/extension of __ptr32
   if ffi.abi("64bit") then
     x.pi = ffi.cast("int *", 15*2^32+0x12345678)
     assert(tonumber(ffi.cast("uintptr_t", x.pi)) == 15*2^32+0x12345678)
@@ -497,8 +533,9 @@ do
     x.pi = x.p32i
     assert(tonumber(ffi.cast("uintptr_t", x.pi)) == 0x12345678)
   end
+end
 
-  -- reference initialization
+do --- reference initialization
   do
     x.ai[0] = 712
     local ri = ffi.new("int &", x.ai)
@@ -506,24 +543,29 @@ do
     local ra = ffi.new("int (&)[10]", ffi.cast("int (*)[10]", x.ai))
     assert(ra[0] == 712)
   end
+end
 
-  -- ffi.sizeof follows references
+do --- ffi.sizeof follows references
   assert(ffi.sizeof(x.ai) == 4*10)
   -- ffi.offsetof follows references
   assert(ffi.offsetof(x.s, "v") == 0)
   assert(ffi.offsetof(x.s, "w") == 4)
+end
 
-  -- ffi.fill writes the right amount
+do --- ffi.fill writes the right amount
   ffi.fill(x.ai2, ffi.sizeof(x.ai2), 0x72)
   ffi.fill(x.ai, ffi.sizeof(x.ai), 0x13)
   assert(x.ai[0] == 0x13131313)
   assert(x.ai[9] == 0x13131313)
   assert(x.ai2[0] == 0x72727272)
   assert(x.ai2[9] == 0x72727272)
+end
 
-  -- array cannot be assigned a pointer
+do --- array cannot be assigned a pointer
   fails(function(x) x.ai = x.pi end, x)
-  -- but pointer can be assigned the address of an array
+end
+
+do --- but pointer can be assigned the address of an array
   x.pi = x.ai2
   assert(x.pi[0] == 0x72727272)
   assert(x.pi[9] == 0x72727272)
@@ -536,7 +578,9 @@ do
   -- reflected via pointer, too
   assert(x.pi[0] == 0x72727272)
   assert(x.pi[9] == 0x72727272)
-  -- mismatched type or size in array copy
+end
+
+do --- mismatched type or size in array copy
   fails(function(x) x.ai = x.ac end, x)
   fails(function(x) x.ai = ffi.new("int[20]") end, x)
   fails(function(x) x.ai = ffi.new("arrinc_t").a end, x)
@@ -547,10 +591,13 @@ do
   x.s.w = 0x789abcde
   assert(x.s.v == 0x12345678)
   assert(x.s.w == 0x789abcde)
+end
 
-  -- struct cannot be assigned a pointer
+do --- struct cannot be assigned a pointer
   fails(function(x) x.s = x.ps end, x)
-  -- but pointer can be assigned the address of a struct
+end
+
+do --- but pointer can be assigned the address of a struct
   x.ps = x.s
   assert(x.ps.v == 0x12345678)
   assert(x.ps.w == 0x789abcde)
@@ -563,12 +610,14 @@ do
   -- reflected via pointer, too
   assert(x.ps.v == 0x59595959)
   assert(x.ps.w == 0x59595959)
+end
 
-  -- structs must be identical, structural equivalence is not enough
+do --- structs must be identical, structural equivalence is not enough
   fails(function(x) x.ps = x.sx end, x)
   fails(function(x) x.s = x.sx end, x)
+end
 
-  -- string copy to arrays
+do --- string copy to arrays
   x.ac_guard = 99
   ffi.fill(x.ac, 10, 0x37)
   x.ac = "ABCD"
@@ -584,27 +633,30 @@ do
   assert(x.ac[9] == 65+9)
   x.ac = "ABCDEFGHIJKLM"
   assert(x.ac[8] == 65+8)
-  assert(x.ac[9] == 65+9)
-  do -- copy to a[?]
-    local vx = ffi.new("struct { char ac[?]; }", 20)
-    ffi.fill(vx.ac, 20, 0x37)
-    vx.ac = "ABCDEFGHI"
-    assert(vx.ac[8] == 65+8)
-    assert(vx.ac[9] == 0)
-  end
-  do -- copy to a[0]
-    local vx = ffi.new("union { char ac[0]; char c[20]; }")
-    ffi.fill(vx.ac, 20, 0x37)
-    vx.ac = "ABCDEFGHI"
-    assert(vx.ac[8] == 65+8)
-    assert(vx.ac[9] == 0)
-  end
-  -- mismatched type or size in string copy
-  fails(function(x) x.i32 = "ABCD" end, x)
-  fails(function(x) x.ai = "ABCD" end, x)
-  assert(x.ac_guard == 99) -- Check guard
+end
+
+do --- copy to a[?]
+  local vx = ffi.new("struct { char ac[?]; }", 20)
+  ffi.fill(vx.ac, 20, 0x37)
+  vx.ac = "ABCDEFGHI"
+  assert(vx.ac[8] == 65+8)
+  assert(vx.ac[9] == 0)
+end
+do --- copy to a[0]
+  local vx = ffi.new("union { char ac[0]; char c[20]; }")
+  ffi.fill(vx.ac, 20, 0x37)
+  vx.ac = "ABCDEFGHI"
+  assert(vx.ac[8] == 65+8)
+  assert(vx.ac[9] == 0)
+end
+
+do --- mismatched type or size in string copy
+fails(function(x) x.i32 = "ABCD" end, x)
+fails(function(x) x.ai = "ABCD" end, x)
+assert(x.ac_guard == 99) -- Check guard
+end
 
-  -- array initialization
+do --- array initialization
   x.ai = ffi.new("int[10]") -- zero fill
   for i=0,9 do assert(x.ai[i] == 0) end
   x.ai = ffi.new("int[10]", -67) -- replicate first element
@@ -617,25 +669,28 @@ do
   for i=0,9 do assert(x.ai[i] == i+1) end
   x.ai = ffi.new("int[10]", {1,2,3,4,5,6,7,8,9,10})
   for i=0,9 do assert(x.ai[i] == i+1) end
-  -- VLA initialization
-  do
-    local v = ffi.new("int[?]", 4)
-    for i=0,3 do assert(v[i] == 0) end
-    local v = ffi.new("int[?]", 4, 833)
-    for i=0,3 do assert(v[i] == 833) end
-    local v = ffi.new("int[?]", 4, 12, -9)
-    assert(v[0] == 12 and v[1] == -9 and v[2] == 0 and v[3] == 0)
-    local v = ffi.new("int[?]", 4, 1,2,3,4)
-    assert(v[0] == 1 and v[1] == 2 and v[2] == 3 and v[3] == 4)
-  end
-  -- too many initializers
+end
+
+do --- VLA initialization
+  local v = ffi.new("int[?]", 4)
+  for i=0,3 do assert(v[i] == 0) end
+  local v = ffi.new("int[?]", 4, 833)
+  for i=0,3 do assert(v[i] == 833) end
+  local v = ffi.new("int[?]", 4, 12, -9)
+  assert(v[0] == 12 and v[1] == -9 and v[2] == 0 and v[3] == 0)
+  local v = ffi.new("int[?]", 4, 1,2,3,4)
+  assert(v[0] == 1 and v[1] == 2 and v[2] == 3 and v[3] == 4)
+end
+
+do --- too many initializers
   fails(function(x) x.ai = {1,2,3,4,5,6,7,8,9,10,11} end, x)
   for i=0,9 do assert(x.ai[i] == i+1) end -- but it's partially executed
   fails(function(x)
     local v = ffi.new("int[?]", 4, 1,2,3,4,5)
   end, x)
+end
 
-  -- struct initialization
+do --- struct initialization
   x.sn = ffi.new("nest_t") -- zero fill
   assert(x.sn.e.e2 == 0)
   x.sn = ffi.new("nest_t", 1,2) -- remainder filled with zero
@@ -650,27 +705,32 @@ do
   assert(x.sn.a == 1 and x.sn.b == 2 and x.sn.c == 3 and x.sn.d == 4)
   assert(x.sn.e.e1 == 5 and x.sn.e.e2 == 6)
   assert(x.sn.f[0] == 7 and x.sn.f[1] == 8)
-  -- VLS initialization
-  do
-    local v = ffi.new("struct { int x; int a[?]; }", 4)
-    assert(v.x == 0)
-    for i=0,3 do assert(v.a[i] == 0) end
-    local v = ffi.new("struct { int x; int a[?]; }", 4, 9, {833})
-    assert(v.x == 9)
-    -- NYI: fill up VLA in VLS. currently seen as indefinite length
-    -- for i=0,3 do assert(v.a[i] == 833) end
-    assert(v.a[0] == 833 and v.a[1] == 0 and v.a[2] == 0 and v.a[3] == 0)
-  end
-  -- no multi-value init beyond first level
+end
+
+do --- VLS initialization
+  local v = ffi.new("struct { int x; int a[?]; }", 4)
+  assert(v.x == 0)
+  for i=0,3 do assert(v.a[i] == 0) end
+  local v = ffi.new("struct { int x; int a[?]; }", 4, 9, {833})
+  assert(v.x == 9)
+  -- NYI: fill up VLA in VLS. currently seen as indefinite length
+  -- for i=0,3 do assert(v.a[i] == 833) end
+  assert(v.a[0] == 833 and v.a[1] == 0 and v.a[2] == 0 and v.a[3] == 0)
+end
+
+do --- no multi-value init beyond first level
   fails(function(x)
     x.sn = ffi.new("nest_t", 1,2,3,4,5,6,7,8)
   end, x)
-  -- too many initializers
+end
+
+do --- too many initializers
   fails(function(x)
     x.sn = ffi.new("nest_t", 1,2,3,4,{5,6},{7,8}, 9)
   end, x)
+end
 
-  -- union initialization
+do --- union initialization
   x.ui = ffi.new("uni_t") -- zero fill
   assert(x.ui.a == 0 and x.ui.b == 0 and x.ui.c == 0)
   x.ui = ffi.new("uni_t", 255) -- initialize first field, remainder is zero
@@ -679,15 +739,18 @@ do
   else
     assert(x.ui.a == -1 and x.ui.b == -256 and x.ui.c == -16777216)
   end
-  -- too many initializers
+end
+
+do --- too many initializers
   fails(function(x)
     x.sn = ffi.new("uni_t", 1,2)
   end, x)
   fails(function()
     ffi.new("union { struct { int x; }; int y; }", 1,2)
   end)
+end
 
-  -- table converted to array
+do --- table converted to array
   ffi.fill(x.ai, ffi.sizeof(x.ai), 0x13)
   x.ai_guard = 99
   x.ai = {} -- zero fill
@@ -701,8 +764,9 @@ do
   assert(x.ai[1] == -27)
   for i=2,9 do assert(x.ai[i] == 0) end
   assert(x.ai_guard == 99) -- Check guard
+end
 
-  -- table converted to struct
+do --- table converted to struct
   ffi.fill(x.si, ffi.sizeof(x.si), 0x74)
   x.si_guard = 97
   -- convert from array part
@@ -724,8 +788,9 @@ do
   x.si = {b = 12, 5, 6, 7} -- hash part ignored if array part exists
   assert(x.si.a == 5 and x.si.b == 6 and x.si.c == 7)
   assert(x.si_guard == 97) -- Check guard
+end
 
-  -- table converted to struct with transparent/nested structs and arrays
+do --- table converted to struct with transparent/nested structs and arrays
   ffi.fill(x.sn, ffi.sizeof(x.sn), 0x74)
   x.sn = {} -- zero fill
   assert(x.sn.e.e2 == 0)
@@ -737,8 +802,9 @@ do
   assert(x.sn.a == 0 and x.sn.b == 0 and x.sn.c == 10 and x.sn.d == 0)
   assert(x.sn.e.e1 == 11 and x.sn.e.e2 == 12)
   assert(x.sn.f[0] == 13 and x.sn.f[1] == 14)
+end
 
-  -- table converted to union
+do --- table converted to union
   ffi.fill(x.ui, ffi.sizeof(x.ui), 0x58)
   x.ui = {} -- zero fill
   assert(x.ui.a == 0 and x.ui.b == 0 and x.ui.c == 0)
@@ -754,22 +820,22 @@ do
   else
     assert(x.ui.a == -1 and x.ui.b == -1 and x.ui.c == -65536)
   end
+end
 
-  -- copy constructor
-  do
-    x.s.v = 1; x.s.w = 2
-    local s = ffi.new("bar_t", x.s)
-    assert(s.v == 1 and s.w == 2)
-    for i=0,9 do x.ai[i] = i end
-    local a = ffi.new("int[10]", x.ai)
-    for i=0,9 do assert(a[i] == i) end
-  end
+do --- copy constructor
+  x.s.v = 1; x.s.w = 2
+  local s = ffi.new("bar_t", x.s)
+  assert(s.v == 1 and s.w == 2)
+  for i=0,9 do x.ai[i] = i end
+  local a = ffi.new("int[10]", x.ai)
+  for i=0,9 do assert(a[i] == i) end
+end
 
-  -- assignment to function pointer
+do --- assignment to function pointer
   x.ppf = ffi.C.strcpy
 end
 
-do
+do --- FFI GC
   collectgarbage()
   local oc = collectgarbage("count")
   local cd = ffi.new"struct { struct { int a; } x;}"
@@ -785,3 +851,9 @@ do
   end
 end
 
+do --- FFI gcstep recursive
+  local stream = io.open("lib/ffi/ffi_gcstep_recursive.lua", "r")
+  local func = assert(load(function(x) stream:read('*all') end))
+  func()
+end
+
diff --git a/test/lib/ffi/ffi_enum.lua b/test/lib/ffi/ffi_enum.lua
index e8e40ad..cbfc25c 100644
--- a/test/lib/ffi/ffi_enum.lua
+++ b/test/lib/ffi/ffi_enum.lua
@@ -1,8 +1,8 @@
 
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
-
+local ffi_util = require("common.ffi_util")
+local fails = ffi_util.fails
 ffi.cdef[[
 typedef enum enum_i { FOO_I = -1, II = 10 } enum_i;
 typedef enum enum_u { FOO_U = 1, UU = 10 } enum_u;
@@ -13,9 +13,9 @@ int call_i_ei(enum_i a) asm("call_i");
 int call_i_eu(enum_u a) asm("call_i");
 ]]
 
-local C = ffi.load("../clib/ctest")
+local C = ffi.load("src/libctest.so")
 
-do
+do --- Enum comparison to strings and integers
 
   local t = ffi.new("enum_i[100]")
   for i=0,99 do t[i] = "II" end
@@ -42,16 +42,17 @@ do
   for i=0,99 do assert(t[i] ~= u[i]) end
 end
 
-do
+do --- Enum comparison to strings
   for i=0,99 do assert(C.call_ei_i(9) == "II") end
   for i=0,99 do assert(C.call_eu_i(9) == "UU") end
   for i=0,99 do assert(C.call_i_ei("II") == 11) end
   for i=0,99 do assert(C.call_i_eu("UU") == 11) end
 end
 
-do
+do --- FFI callbacks returning enums
   local f = ffi.cast("bool (*)(enum_i)", function(e) return e == "II" end)
   assert(f("II"))
   assert(not f(0))
+  f:free()
 end
 
diff --git a/test/lib/ffi/ffi_jit_arith.lua b/test/lib/ffi/ffi_jit_arith.lua
index 0554fe6..6a0ba19 100644
--- a/test/lib/ffi/ffi_jit_arith.lua
+++ b/test/lib/ffi/ffi_jit_arith.lua
@@ -1,6 +1,6 @@
 local ffi = require("ffi")
 
-do
+do --- Test FFI compilation
   local a = ffi.new("int64_t[?]", 101)
   for i=1,100 do a[i] = -2 end
   for i=1,100 do a[i] = i end
@@ -29,7 +29,7 @@ do
   assert(w == 5050)
 end
 
-do
+do --- More FFI compilation tests
   local a = ffi.new("uint64_t[?]", 101)
   for i=1,100 do a[i] = i end
   local x, y, m = 0ull, 0ull, 0ull
@@ -48,32 +48,32 @@ do
   assert(z == 0x123456789abcdef0ull % 100)
 end
 
-do
+do --- Test JITing of the bit library
   local x = 0ll
   for i=1,100 do x = x + (-2ll) ^ (bit.band(i, 15)+1ll) end
   assert(x == 262120)
 end
 
-do
+do --- More bit library tests
   local x, a = 0ll, -2ll
   for i=1,100 do x = x + a ^ (bit.band(i, 15)+1ll) end
   assert(x == 262120)
 end
 
-do
+do --- Still more bit library tests
   local x = 0ull
   for i=1,100 do x = x + (-2ll) ^ (bit.band(i, 15)+1ull) end
   assert(x == 262120)
 end
 
-do
+do --- Even more bitwise jitting test
   for i=1,200 do local j = bit.band(i, 7); assert((j == 0ll) == (j == 0)) end
   for i=1,200 do assert((i < 100ll) == (i < 100)) end
   for i=1,200 do assert((i <= 100ll) == (i <= 100)) end
   for i=-100,100 do assert((i > 100ull) == (i < 0)) end
 end
 
-do
+do --- FFI array compilation
   local a = ffi.new("int64_t[?]", 100)
   for i=0,99 do
     a[i] = math.random(0, 2^32)*0x100000000LL + math.random(0, 2^32)
@@ -121,13 +121,13 @@ do
   end
 end
 
-do
+do --- Pointer arithmetic doesn't crash
   local a, b = ffi.new("char *"), ffi.new("char *")
   local z
   for i=1,100 do z = a-b end
 end
 
-do
+do --- comparisons between char pointers and Lua strings
   local x = true
   local abc = ffi.cast("const char *", "abc")
   for i=1,100 do x = abc == "abc" end
@@ -142,8 +142,7 @@ do
   assert(x == false)
 end
 
--- ra_destpair
-do
+do --- ra_destpair
   local x, y = 0, 0
   for i=1,100 do
     x = x + i/3LL
diff --git a/test/lib/ffi/ffi_jit_call.lua b/test/lib/ffi/ffi_jit_call.lua
index b79d60b..aac2771 100644
--- a/test/lib/ffi/ffi_jit_call.lua
+++ b/test/lib/ffi/ffi_jit_call.lua
@@ -35,9 +35,9 @@ double __stdcall stdcall_dd(double a, double b);
 float __stdcall stdcall_ff(float a, float b);
 ]]
 
-local lib = ffi.load("../clib/ctest")
+local lib = ffi.load("./ctest.so")
 
-do
+do --- Basic calls
   local x
   for i=1,100 do
     x = lib.call_10i(-42, 17, 12345, 9987, -100, 11, 51, 0x12345678, 338, -78901234)
@@ -45,12 +45,13 @@ do
   assert(x == -42+17+12345+9987-100+11+51+0x12345678+338-78901234)
 end
 
-do
+do --- More basic calls
   for i=1,100 do
     pcall(lib.call_max, i,i,i,i,i,i,i,i,i,i,i,i,i,i,i,i,i)
   end
 end
 
+do --- 64-bit only
 if ffi.abi("64bit") then
   local y = ffi.cast("void *", 0x123456789abcdefLL)
   local x
@@ -60,8 +61,9 @@ if ffi.abi("64bit") then
   end
   assert(x == 0)
 end
+end
 
-do
+do --- Calls with 64-bit integers
   local x = 0
   for i=1,100 do
     x = x + lib.call_ij(100+i, i*0x300000002LL)
@@ -69,7 +71,7 @@ do
   assert(x == 0x3b2e0000623eLL)
 end
 
-do
+do --- Calls with floating-point numbers
   local x
   for i=1,100 do
     x = lib.call_10d(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x12345678, 338, -78901234.75)
@@ -77,7 +79,7 @@ do
   assert(x == -42.5+17.125+12345.5+9987-100.625+11+51+0x12345678+338-78901234.75)
 end
 
-do
+do --- More floating-point numbers
   local x
   for i=1,100 do
     x = lib.call_10f(-42.5, 17.125, 12345.5, 9987, -100.625, 11, 51, 0x123456, 338, -789012.75)
@@ -85,7 +87,7 @@ do
   assert(x == -42.5+17.125+12345.5+9987-100.625+11+51+0x123456+338-789012.75)
 end
 
-do
+do --- More FFI calls
   local x
   for i=-100,100 do
     if not lib.call_b(i) then x = i end
@@ -100,14 +102,14 @@ do
   assert(x == 90)
 end
 
-do
+do --- FFI tail calls
   local function tail(x)
     return lib.call_b(x)
   end
   for i=1,100 do local a,b,c = tail(1), tail(1), tail(1) end
 end
 
-do
+do --- FFI narrowing conversions
   local x = 0
   for i=0x01010080,0x010100ff do x = x + lib.call_i_i8(i) end
   assert(x == -8128)
@@ -134,7 +136,7 @@ do
   assert(x == 8380480)
 end
 
--- target-specific
+do --- target-specific
 if jit.arch == "x86" then
   for i=1,100 do assert(lib.fastcall_i(-42) == -41) end
   for i=1,100 do assert(lib.fastcall_ii(-42, 17) == -42+17) end
@@ -151,4 +153,5 @@ if jit.arch == "x86" then
     for i=1,100 do assert(lib.stdcall_ff(12.5, -3.25) == 12.5-3.25) end
   end
 end
+end
 
diff --git a/test/lib/ffi/ffi_jit_conv.lua b/test/lib/ffi/ffi_jit_conv.lua
index d4707db..08b8d50 100644
--- a/test/lib/ffi/ffi_jit_conv.lua
+++ b/test/lib/ffi/ffi_jit_conv.lua
@@ -2,7 +2,7 @@ local ffi = require("ffi")
 
 local ctest = require("ctest")
 
-do
+do --- FFI narrowing
   local s = ffi.new("struct { int32_t x; }")
   s.x = -0x12345678
   for i=1,100 do
@@ -11,7 +11,7 @@ do
   assert(s.x == -0x12345678+100)
 end
 
-do
+do --- Conversions between uint32_t and Lua numbers
   local s = ffi.new("struct { uint32_t x; }")
   s.x = 0x81234567
   for i=1,100 do
@@ -20,7 +20,7 @@ do
   assert(s.x == 0x81234567+100)
 end
 
-do
+do --- Conversions between integers and int8_t
   local s = ffi.new("struct { int8_t x; }")
   s.x = 42
   for i=1,100 do
@@ -30,7 +30,7 @@ do
   assert(s.x == 142-256)
 end
 
-do
+do --- Conversions between integers and uint8_t
   local s = ffi.new("struct { uint8_t x; }")
   s.x = 200
   for i=1,100 do
@@ -40,7 +40,7 @@ do
   assert(s.x == 300-256)
 end
 
-do
+do --- Conversions between integers and int16_t
   local s = ffi.new("struct { int16_t x; }")
   s.x = 32700
   for i=1,100 do
@@ -50,7 +50,7 @@ do
   assert(s.x == 32800-65536)
 end
 
-do
+do --- Conversions between integers and uint16_t
   local s = ffi.new("struct { uint16_t x; }")
   s.x = 65450
   for i=1,100 do
@@ -60,7 +60,7 @@ do
   assert(s.x == 65550-65536)
 end
 
-do
+do --- Conversions between numbers, integers, and uint32_t
   local s = ffi.new("union { int32_t x; uint32_t y; }")
   s.x = 0x7fffffff - 60
   local x,y = 0,0
@@ -75,7 +75,7 @@ do
   assert(x == y - 40*2^32)
 end
 
-do
+do --- Conversions between integers and uint32_t
   local s = ffi.new("union { int32_t x; uint32_t y; }")
   local x, z = 0, 2^31 + 42
   for i=1,100 do
@@ -85,7 +85,7 @@ do
   assert(x == 100*(-2^31 + 42))
 end
 
-do
+do --- fwd -> CONV.int.i8, CONV.num.int, CONV.int.u8
   local s = ffi.new("union { int8_t x; uint8_t y; }")
   s.x = 42
   local x,y = 0,0
@@ -100,7 +100,7 @@ do
   assert(x == y - (100-(127-42))*256)
 end
 
-do
+do --- FOLD TOBIT + CONV.num.u32
   local a = ffi.new("uint32_t[?]", 101)
   for i=1,100 do a[i] = 0x80000000+i end
   local x = 0
@@ -110,7 +110,7 @@ do
   assert(x == 100)
 end
 
-do
+do --- FOLD TOBIT + CONV.num.u32
   local a = ffi.new("uint32_t[?]", 101)
   for i=1,100 do a[i] = 0x80000000+i end
   local x = 0
@@ -120,7 +120,7 @@ do
   assert(x == -0x80000000+100)
 end
 
-do
+do --- CONV.num.flt
   local v = ffi.new("float", 12.5)
   local x = 0
   for i=1,100 do
@@ -129,7 +129,7 @@ do
   assert(x == 100*12.5)
 end
 
-do
+do --- CONV.num.u32
   local v = ffi.new("uint32_t", 0x80000000)
   local x = 0
   for i=1,100 do
@@ -138,7 +138,7 @@ do
   assert(x == 100*0x80000000)
 end
 
-do
+do --- CONV.num.i64
   local v = ffi.new("int64_t", 0x1234567800000000ll)
   local x = 0
   for i=1,100 do
@@ -147,7 +147,7 @@ do
   assert(x == 100*0x12345678*2^32)
 end
 
-do
+do --- CONV.num.u64
   local v = ffi.new("uint64_t", 0x89abcdef00000000ull)
   local x = 0
   for i=1,100 do
@@ -156,7 +156,7 @@ do
   assert(x == 100*0x89abcdef*2^32)
 end
 
-do
+do --- CONV.num.i64
   local a = ffi.new("int64_t[?]", 101)
   for i=1,100 do a[i] = -i end
   local x = 0
@@ -166,7 +166,7 @@ do
   assert(x == -5050)
 end
 
-do
+do --- CONV.num.u64
   local a = ffi.new("uint64_t[?]", 101)
   for i=1,100 do a[i] = 2^63+2^32*i end
   local x = 0
@@ -176,7 +176,7 @@ do
   assert(x == 2^63*100+2^32*5050)
 end
 
-do
+do --- Conversions between complex and other types
   local v = ffi.new("complex", 12.5, -3.25)
   local x = 0
   for i=1,100 do
@@ -185,7 +185,7 @@ do
   assert(x == 100*12.5)
 end
 
-do
+do --- int64_t conversions
   local s = ffi.new("struct { int64_t x;}")
   for i=1,100 do
     s.x = 0x123456789abcdef0LL
@@ -193,7 +193,7 @@ do
   assert(tonumber(s.x) == tonumber(0x123456789abcdef0LL))
 end
 
-do
+do --- uint64_t conversions
   local s = ffi.new("struct { uint64_t x;}")
   for i=1,100 do
     s.x = 0x823456789abcdef0ULL
@@ -201,7 +201,7 @@ do
   assert(tonumber(s.x) == tonumber(0x823456789abcdef0ULL))
 end
 
-do
+do --- FFI enum conversions
   ffi.cdef[[
   typedef enum { AA, BB, CC = -42 } foo_i;
   typedef enum { DD, EE, FF = 0x80000000u } foo_u;
@@ -229,7 +229,7 @@ do
   assert(x == -42)
 end
 
-do
+do --- Conversions between strings and const char *
   local s = ffi.new("struct { const char *x; const char *y;}")
   local a, tmp = "abcd", "ab"
   for i=1,100 do
@@ -240,7 +240,7 @@ do
   assert(ffi.string(s.y) == "ab")
 end
 
-do
+do --- Conversions between int, bool, and double
   local s = ffi.new("struct { bool b[200]; int i[200]; double d[200];}")
   for i=0,199 do s.i[i] = i-100; s.d[i] = i-100 end
   for i=0,99 do s.b[i] = 0 end
@@ -253,13 +253,13 @@ do
   for i=0,199 do assert(s.b[i] == (i ~= 100)) end
 end
 
-do
+do --- Conversions involving int16_t
   local a = ffi.new("int16_t[100]", 1)
   for i=1,99 do a[i] = a[i] + a[i-1] end
   assert(a[99] == 100)
 end
 
-do
+do --- Casting between light userdata, void*, and uintptr_t
   local ud = ctest.lightud(12345678)
   local s = ffi.new("struct { void *p; }")
   for i=1,100 do
@@ -269,7 +269,7 @@ do
   assert(ffi.cast("uintptr_t", s.p) == 12345678)
 end
 
-do
+do --- FFI reference conversions
   local x = ffi.new("struct { int & x;}", ffi.new("int[1]", 42))
   local z
   for i=1,100 do z = x.x end
diff --git a/test/lib/ffi/ffi_lex_number.lua b/test/lib/ffi/ffi_lex_number.lua
index e26650e..7281746 100644
--- a/test/lib/ffi/ffi_lex_number.lua
+++ b/test/lib/ffi/ffi_lex_number.lua
@@ -1,7 +1,6 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
-
+local ffi_util = require("common.ffi_util")
 local function checklex(t)
   for i=1,1e9,2 do
     local s = t[i+1]
@@ -13,7 +12,7 @@ local function checklex(t)
     end
   end
 end
-
+do --- FFI C parser lexes numbers correctly
 checklex{
   "0LL",			"0ll",
   "0LL",			"0LL",
@@ -37,7 +36,7 @@ checklex{
   "0-0i",			"-0i",
 }
 
-checkfail({
+ffi_util.checkfail({
   "0l",
   "0lll",
   "0u",
@@ -48,4 +47,5 @@ checkfail({
   ".0ll",
   "0ii",
 }, function(s) assert(loadstring("return "..s)) end)
+end
 
diff --git a/test/lib/ffi/ffi_metatype.lua b/test/lib/ffi/ffi_metatype.lua
index 2db717f..04daf99 100644
--- a/test/lib/ffi/ffi_metatype.lua
+++ b/test/lib/ffi/ffi_metatype.lua
@@ -1,6 +1,8 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+
+local fails = ffi_util.fails
 
 ffi.cdef[[
 typedef struct { int x; } idx1_t;
@@ -14,8 +16,11 @@ local function ptreq(a, b)
   return ffi.cast("void *", a) == ffi.cast("void *", b)
 end
 
-do
-  local nidx = {}
+local cs
+local s
+local nidx = {}
+
+do --- FFI metatypes can only be set once
   local tp = ffi.metatype("idx1_t", {
     __index = { foo = 99, method = function(c, v) return v end },
     __newindex = nidx,
@@ -23,29 +28,33 @@ do
 
   fails(function() ffi.metatype("idx1_t", {}) end)
 
-  local s = tp(1234)
+  s = tp(1234)
   assert(s.foo == 99)
   assert(s.x == 1234)
-  -- bad field in __index metatable
+end
+
+do --- bad field in __index metatable
   fails(function(s) local x = s.bar end, s)
   assert(s:method(123) == 123)
   s.bar = 42
   assert(nidx.bar == 42)
+end
 
-  local cs = ffi.new("const idx1_t", 9876)
+do --- write to const struct
+  cs = ffi.new("const idx1_t", 9876)
   assert(cs.foo == 99)
   assert(cs.x == 9876)
-  -- write to const struct
   fails(function(cs) cs.bar = 42 end, cs)
+end
 
+do --- write to const struct pointer
   local cp = ffi.new("const idx1_t *", cs)
   assert(cp.foo == 99)
   assert(cp.x == 9876)
-  -- write to const struct pointer
   fails(function(cp) cp.bar = 42 end, cp)
 end
 
-do
+do --- misc FFI metatables
   local uc, uk, uv
   local tp = ffi.metatype("idx2_t", {
     __index = function(c, k, x, y)
@@ -78,7 +87,7 @@ do
   fails(function(p) p[0] = 11 end, p)
 end
 
-do
+do --- more misc FFI metatype stuff
   local uc, uk, uv
   local ti, tn = {}, {}
   local tp = ffi.metatype("idx3_t", {
@@ -103,7 +112,7 @@ do
   uc, uk, uv = nil, nil, nil
 end
 
-do
+do --- FFI arithmatic metamethods
   local tp
   tp = ffi.metatype("arith_t", {
     __add = function(a, b) return tp(a.x+b.x, a.y+b.y) end,
@@ -174,7 +183,7 @@ do
   assert(x == 3000)
 end
 
-do
+do --- ffi.gc works
   local count = 0
   local tp = ffi.metatype("gc_t", {
     __gc = function(x) count = count + 1 end,
@@ -206,7 +215,7 @@ do
   assert(count == 103)
 end
 
-do
+do --- FFI metatable index works
   local tp = ffi.metatype([[
 struct {
   static const int Z42 = 42;
@@ -236,10 +245,9 @@ struct {
   assert(o.x == 5)
 end
 
-do
+do --- FFI structs can be used as __index tables
   local fb = ffi.new("struct { int x; }", 99)
   local xt = ffi.metatype("struct { }", { __index = fb })
   local o = xt()
   assert(o.x == 99)
 end
-
diff --git a/test/lib/ffi/ffi_new.lua b/test/lib/ffi/ffi_new.lua
index 9cdbd53..f9a1127 100644
--- a/test/lib/ffi/ffi_new.lua
+++ b/test/lib/ffi/ffi_new.lua
@@ -1,7 +1,7 @@
 local ffi = require("ffi")
 local bit = require("bit")
-
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local fails = ffi_util.fails
 
 ffi.cdef([[
 typedef struct { int a,b,c; } foo1_t;
@@ -10,7 +10,7 @@ void *malloc(size_t size);
 void free(void *ptr);
 ]])
 
-do
+do --- FFI new test 1
   assert(ffi.sizeof("foo1_t") == 12)
   local cd = ffi.new("foo1_t")
   assert(ffi.sizeof(cd) == 12)
@@ -20,7 +20,7 @@ do
   assert(ffi.sizeof(cd) == 12)
 end
 
-do
+do --- FFI new test 2
   assert(ffi.sizeof("foo2_t", 3) == 12)
   local cd = ffi.new("foo2_t", 3)
   assert(ffi.sizeof(cd) == 12)
@@ -31,7 +31,7 @@ do
   assert(ffi.sizeof(cd) == 12)
 end
 
-do
+do --- FFI new test 3
   local tpi = ffi.typeof("int")
   local tpb = ffi.typeof("uint8_t")
   local t = {}
@@ -42,7 +42,7 @@ do
   assert(x == 199*257 + 1)
 end
 
-do
+do --- FFI alignment test
   local oc = collectgarbage("count")
   for al=0,15 do
     local align = 2^al -- 1, 2, 4, ..., 32768
@@ -57,14 +57,14 @@ do
   assert(nc < oc + 3000, "GC step missing for ffi.new")
 end
 
-do
+do --- FFI new of variable-sized array
   local t = {}
   for i=1,100 do t[i] = ffi.new("int[?]", i) end
   assert(ffi.sizeof(t[100]) == 400)
   for i=0,99 do assert(t[100][i] == 0) end
 end
 
-do
+do --- FFI new of variable-sized array in struct
   local t = {}
   local ct = ffi.typeof("struct { double x; int y[?];}")
   for i=1,100 do t[i] = ct(i) end
@@ -72,7 +72,7 @@ do
   for i=0,99 do assert(t[100].y[i] == 0) end
 end
 
-do
+do --- FFI alignment test 2
   local ct = ffi.typeof("struct __attribute__((aligned(16))) { int x; }")
   local y
   for i=1,200 do
@@ -82,7 +82,7 @@ do
   assert(bit.band(ffi.cast("intptr_t", ffi.cast("void *", y)), 15) == 0)
 end
 
-do
+do --- FFI GC test
   local q
   local p = ffi.gc(ffi.new("int[1]"), function(x) q = x end)
   p = nil
@@ -93,13 +93,13 @@ do
   assert(q == nil)
 end
 
-do
+do --- FFI GC test 2
   local p = ffi.gc(ffi.C.malloc(2^20), ffi.C.free)
   p = nil
   collectgarbage()
 end
 
-do
+do --- lua_close can cleanup cdata correctly
   local p = ffi.gc(ffi.new("int[1]"), function(x) assert(type(x) == "cdata") end)
   -- test for lua_close() cleanup.
 end
diff --git a/test/lib/ffi/ffi_parse_array.lua b/test/lib/ffi/ffi_parse_array.lua
index 3a9616d..6ae634f 100644
--- a/test/lib/ffi/ffi_parse_array.lua
+++ b/test/lib/ffi/ffi_parse_array.lua
@@ -1,75 +1,81 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local P = ffi.sizeof("void *")
 
-checkfail{
-  "int [",
-  "int [-1]",
-  "int [[1]]",
-  "int [10][]",
-  "int [10][?]",
-  "int [][]",
-  "int [][?]",
-  "int [?][]",
-  "int [?][?]",
-  "int [0x10000][0x2000]",
-  "int [256][256][256][256]",
-  "int [10](void)",
-  "int (void)[10]",
-  "int &[10]",
-  "union { double x; int a[?]; }",
-}
+do --- FFI parse errors
+  ffi_util.checkfail{
+    "int [",
+    "int [-1]",
+    "int [[1]]",
+    "int [10][]",
+    "int [10][?]",
+    "int [][]",
+    "int [][?]",
+    "int [?][]",
+    "int [?][?]",
+    "int [0x10000][0x2000]",
+    "int [256][256][256][256]",
+    "int [10](void)",
+    "int (void)[10]",
+    "int &[10]",
+    "union { double x; int a[?]; }",
+  }
+end
 
-ffi.cdef([[
-  typedef int foo1_t[10];
-  typedef foo1_t foo2_t[5];
-]])
-assert(ffi.sizeof("foo1_t") == 40)
-assert(ffi.sizeof("foo2_t") == 200)
+do --- FFI array typedef sizeof
+  ffi.cdef([[
+    typedef int foo1_t_[10];
+    typedef foo1_t_ foo2_t_[5];
+  ]])
+  assert(ffi.sizeof("foo1_t_") == 40)
+  assert(ffi.sizeof("foo2_t_") == 200)
+end
 
-local P = ffi.sizeof("void *")
 
-checktypes{
-  10,	1,	"char [10]",
-  4*10,	4,	"int [10]",
-  4*10,	4,	"int [10]",
-  4*10*5, 4,	"int [10][5]",
-  4*10*5*3*2*7, 4,	"int [10][5][3][2][7]",
-  4*10*5, 4,	"int ([10])[5]",
-  P*10,	P,	"int *[10]",
-  P,	P,	"int (*)[10]",
-  P*5,	P,	"int (*[5])[10]",
-  8*10,	4,	"struct { int x; char y; } [10]",
-  P*5*10, P,	"volatile int *(* const *[5][10])(void)",
-  nil,	4,	"int []",
-  4*10,	8,	"int __attribute__((aligned(8))) [10]",
-  4*10,	8,	"__attribute__((aligned(8))) int [10]",
-  4*10,	8,	"int [10] __attribute__((aligned(8)))",
-  97,	1,	"char ['a']",
-  83,	1,	"char ['\\123']",
-  79,	1,	"char ['\x4F']",
-  5,	1,	"char [sizeof(\"aa\" \"bb\")]",
-  80,	8,	"double [10]",
-}
+do --- FFI array parsing
+  ffi_util.checktypes{
+    10,	1,	"char [10]",
+    4*10,	4,	"int [10]",
+    4*10,	4,	"int [10]",
+    4*10*5, 4,	"int [10][5]",
+    4*10*5*3*2*7, 4,	"int [10][5][3][2][7]",
+    4*10*5, 4,	"int ([10])[5]",
+    P*10,	P,	"int *[10]",
+    P,	P,	"int (*)[10]",
+    P*5,	P,	"int (*[5])[10]",
+    8*10,	4,	"struct { int x; char y; } [10]",
+    P*5*10, P,	"volatile int *(* const *[5][10])(void)",
+    nil,	4,	"int []",
+    4*10,	8,	"int __attribute__((aligned(8))) [10]",
+    4*10,	8,	"__attribute__((aligned(8))) int [10]",
+    4*10,	8,	"int [10] __attribute__((aligned(8)))",
+    97,	1,	"char ['a']",
+    83,	1,	"char ['\\123']",
+    79,	1,	"char ['\x4F']",
+    5,	1,	"char [sizeof(\"aa\" \"bb\")]",
+    80,	8,	"double [10]",
+  }
+end
 
-do
+do --- FFI sizeof and typeof for arrays
   assert(ffi.sizeof("int [?]", 10) == 4*10)
   local id = ffi.typeof("const short [?]")
   assert(ffi.sizeof(id, 10) == 2*10)
   assert(ffi.sizeof(id, 0) == 0*10)
-  fails(ffi.sizeof, id)
+  ffi_util.fails(ffi.sizeof, id)
   assert(ffi.sizeof(id, -1) == nil)
   assert(ffi.sizeof(id, 0x80000000) == nil)
   assert(ffi.sizeof(id, 0x40000000) == nil)
   assert(ffi.sizeof(id, 0x3fffffff) == 2*0x3fffffff)
 end
 
-do
+do --- More ffi sizeof and typeof for arrays
   assert(ffi.sizeof("struct { double x; int a[?]; }", 10) == 8+4*10)
   local id = ffi.typeof("struct { int x; short a[?]; }")
   assert(ffi.sizeof(id, 10) == 4+2*10)
   assert(ffi.sizeof(id, 0) == 4+0*10)
-  fails(ffi.sizeof, id)
+  ffi_util.fails(ffi.sizeof, id)
   assert(ffi.sizeof(id, -1) == nil)
   assert(ffi.sizeof(id, 0x80000000) == nil)
   assert(ffi.sizeof(id, 0x40000000) == nil)
diff --git a/test/lib/ffi/ffi_parse_basic.lua b/test/lib/ffi/ffi_parse_basic.lua
index c054bcf..1d37449 100644
--- a/test/lib/ffi/ffi_parse_basic.lua
+++ b/test/lib/ffi/ffi_parse_basic.lua
@@ -1,7 +1,12 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local checkfail, checktypes = ffi_util.checkfail, ffi_util.checktypes
+local L = (ffi.abi("32bit") or ffi.abi("win")) and 4 or 8
+local P = ffi.abi("32bit") and 4 or 8
+local W = ffi.abi("win") and 2 or 4
 
+do --- FFI syntax errors
 checkfail{
   "",
   " ",
@@ -32,8 +37,10 @@ checkfail{
   "int double",
   "int;",
 }
+end
 
-checktypes{
+do --- FFI comments and sizeof(char)
+ffi_util.checktypes{
   1,	1,	"char",
   1,	1,	" \n\r\t\vchar \n\r\t\v",
   1,	1,	"ch\\\nar",
@@ -41,7 +48,9 @@ checktypes{
   1,	1,	"char /* abc */ const",
   1,	1,	"char // abc\n const",
 }
+end
 
+do --- properties of primitive types
 checktypes{
   nil,	1,	"void",
   1,	1,	"bool",
@@ -68,8 +77,9 @@ checktypes{
   16,	8,	"_Complex",
   16,	8,	"_Complex double",
 }
+end
 
--- mode/vector_size attributes
+do --- mode/vector_size attributes
 checktypes{
   1,	1,	"int __attribute__((mode(QI)))",
   2,	2,	"int __attribute__((mode(HI)))",
@@ -87,12 +97,9 @@ checktypes{
   32,	16,	"double __attribute__((vector_size(32)))",
   64,	16,	"double __attribute__((vector_size(64)))",
 }
+end
 
--- ABI-specific types:
-local L = (ffi.abi("32bit") or ffi.abi("win")) and 4 or 8
-local P = ffi.abi("32bit") and 4 or 8
-local W = ffi.abi("win") and 2 or 4
-
+do --- Properties of integer and pointer types
 checktypes{
   L,	L,	"long",
   L,	L,	"signed long",
@@ -101,10 +108,12 @@ checktypes{
   P,	P,	"int **",
   4,	4,	"int * __ptr32",
 }
+end
 
+do --- Properties of stdint.h types
 checktypes{
-  P,	P,	"ptrdiff_t",
   P,	P,	"size_t",
+  P,	P,	"ptrdiff_t" ,
   W,	W,	"wchar_t",
   1,	1,	"int8_t",
   2,	2,	"int16_t",
@@ -117,7 +126,9 @@ checktypes{
   P,	P,	"intptr_t",
   P,	P,	"uintptr_t",
 }
+end
 
+do --- Attributes dictating alignment
 checktypes{
   1,	8,	"char __attribute__((aligned(8)))",
   1,	8,	"char __attribute((aligned(8)))",
@@ -128,4 +139,5 @@ checktypes{
   1,	2,	"char __attribute__((aligned(8))) const __attribute__((aligned(2)))",
   1,	16,	"char __attribute__((aligned(8))) const __attribute__((aligned(16)))",
 }
+end
 
diff --git a/test/lib/ffi/ffi_parse_cdef.lua b/test/lib/ffi/ffi_parse_cdef.lua
index 4bb5d90..67cf8f1 100644
--- a/test/lib/ffi/ffi_parse_cdef.lua
+++ b/test/lib/ffi/ffi_parse_cdef.lua
@@ -1,7 +1,10 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local checkfail, checktypes, fails =
+  ffi_util.checkfail, ffi_util.checktypes, ffi_util.fails
 
+do --- Invalid FFI declarations rejected
 checkfail({
   "int",
   "int aa1; int aa2 ",
@@ -12,7 +15,9 @@ checkfail({
   "struct { static int x = 1; };",
   ";;static int y"
 }, ffi.cdef)
+end
 
+do --- FFI const definitions
 ffi.cdef[[
 static const int K_42a = 42;
 static const char K_42b = 42+256;
@@ -22,7 +27,9 @@ static const int K_1b = 0xffffffff >> 31;
 static const int K_1c = 0xffffffffu >> 31;
 static const int K_M1b = (int)0xffffffff >> 31;
 ]]
+end
 
+do --- Arrays with size given by consts
 checktypes{
   42,	1,	"char[K_42a]",
   42,	1,	"char[K_42b]",
@@ -32,7 +39,9 @@ checktypes{
   1,	1,	"char[K_1c]",
   1,	1,	"char[-K_M1b]",
 }
+end
 
+do --- Static consts in structs
 ffi.cdef[[
 struct str1 {
   enum {
@@ -41,7 +50,9 @@ struct str1 {
   static const int K_55 = 55;
 } extk;
 ]]
+end
 
+do --- Constant expression evaluation works
 checktypes{
   99,	1,	"char[K_99]",
   99,	1,	"char[extk.K_99]",
@@ -49,11 +60,15 @@ checktypes{
   99,	1,	"char[((struct str1 *)0)->K_99]",
   55,	1,	"char[extk.K_55]",
 }
+end
 
+do --- Static consts in structs do not have global scope
 checkfail{
   "char[K_55]",
 }
+end
 
+do --- Inline function definitions ignored
 ffi.cdef[[
 extern int func1(void);
 extern int func2();
@@ -69,9 +84,11 @@ static inline int func4(int n)
 }
 ;;;
 ]]
+end
 
+do --- Extern variables
 ffi.cdef[[
 int ext1;
 extern int ext2;
 ]]
-
+end
diff --git a/test/lib/ffi/ffi_parse_struct.lua b/test/lib/ffi/ffi_parse_struct.lua
index 16a3d05..b4d036b 100644
--- a/test/lib/ffi/ffi_parse_struct.lua
+++ b/test/lib/ffi/ffi_parse_struct.lua
@@ -1,7 +1,13 @@
 local ffi = require("ffi")
 
-dofile("../common/ffi_util.inc")
+local ffi_util = require("common.ffi_util")
+local checkfail, checktypes, fails =
+  ffi_util.checkfail, ffi_util.checktypes, ffi_util.fails
 
+local P = ffi.sizeof("void *")
+local A = (ffi.arch == "x86" and not ffi.abi("win")) and 4 or 8
+
+do --- Invalid FFI declarations rejected
 checkfail{
   "struct",
   "struct {",
@@ -22,30 +28,31 @@ checkfail{
   "union { int x(void); }",
   "union recursive1 { union recursive1 { } x; }",
 }
+end
 
 -- NYI: rollback doesn't recover struct state
 -- ffi.cdef("struct zzz")
 -- fails(ffi.cdef, "struct zzz { int")
 -- ffi.cdef("struct zzz { int x; }")
 
-ffi.cdef("struct foo; typedef struct foo foo_t;")
-assert(ffi.sizeof("struct foo") == nil)
-assert(ffi.sizeof("foo_t") == nil)
-ffi.cdef("struct foo { int x,y; };")
-assert(ffi.sizeof("struct foo") == 8)
-assert(ffi.sizeof("foo_t") == 8)
-assert(ffi.sizeof(ffi.typeof("struct foo")) == 8)
-assert(ffi.sizeof(ffi.typeof("foo_t")) == 8)
-ffi.cdef("struct foo;")
-fails(ffi.cdef, "struct foo {};")
-fails(ffi.cdef, "union foo;")
-fails(ffi.cdef, "union foo {};")
-fails(ffi.cdef, "enum foo;")
-fails(ffi.cdef, "enum foo { ZZZ1 };")
-
-local P = ffi.sizeof("void *")
-local A = (ffi.arch == "x86" and not ffi.abi("win")) and 4 or 8
+do --- FFI sizeof on opaque types
+ffi.cdef("struct $; typedef struct $ foo_t_;", 'foo_', 'foo_')
+assert(ffi.sizeof("struct foo_") == nil)
+assert(ffi.sizeof("foo_t_") == nil)
+ffi.cdef("struct foo_ { int x,y; };")
+assert(ffi.sizeof("struct foo_") == 8)
+assert(ffi.sizeof("foo_t_") == 8)
+assert(ffi.sizeof(ffi.typeof("struct foo_")) == 8)
+assert(ffi.sizeof(ffi.typeof("foo_t_")) == 8)
+ffi.cdef("struct foo_;")
+fails(ffi.cdef, "struct foo_ {};")
+fails(ffi.cdef, "union foo_;")
+fails(ffi.cdef, "union foo_ {};")
+fails(ffi.cdef, "enum foo_;")
+fails(ffi.cdef, "enum foo_ { ZZZ1 };")
+end
 
+do --- FFI struct alignof and sizeof
 checktypes{
   0,	1,	"struct {}",
   1,	1,	"struct { char x; }",
@@ -59,9 +66,9 @@ checktypes{
   P*4,	P,	"struct { char x,*y,**z,a,b,c,d; }",
   64,	4,	"struct { struct { struct { struct { int x,y; } a,b; } a,b; } a,b; }",
   4,	4,	"struct { struct { struct { struct { int x; }; }; }; }",
-  8,	4,	"struct { struct foo; }",
-  8,	4,	"struct { foo_t; }",
-  8,	8,	"struct __attribute__((aligned(sizeof(foo_t)))) { int a; }",
+  8,	4,	"struct { struct foo_ q; }",
+  8,	4,	"struct { foo_t_ q; }",
+  8,	8,	"struct __attribute__((aligned(sizeof(foo_t_)))) { int a; }",
   6,	2,	"struct { char a; char x; short y; char z; char c; }",
   10,	2,	"struct { char a; struct { char x; short y; char z; } b; char c; }",
   8,	A,	"struct { double a; }",
@@ -77,7 +84,9 @@ checktypes{
   16,	16,	"struct { float __attribute__((vector_size(16))) a; }",
   32,	16,	"struct { int a; float __attribute__((vector_size(16))) b; }",
 }
+end
 
+do --- FFI union size and alignment
 checktypes{
   0,	1,	"union {}",
   1,	1,	"union { char x; }",
@@ -106,8 +115,9 @@ checktypes{
   16,	16,	"union { float __attribute__((vector_size(16))) a; }",
   16,	16,	"union { int a; float __attribute__((vector_size(16))) b; }",
 }
+end
 
-do
+do --- FFI offsetof
   local ct
   ct = ffi.typeof("struct { int a; char b; short c; int d; }")
   assert(ffi.offsetof(ct, "a") == 0)
@@ -129,6 +139,7 @@ do
   assert(ffi.offsetof(ct, "b") == A)
 end
 
+do --- Invalid FFI declarations rejected
 checkfail{
   "struct { int :; }",
   "struct { int a:; }",
@@ -144,7 +155,9 @@ checkfail{
   "struct { int a[2]:2; }",
   "struct { void a:2; }",
 }
+end
 
+do --- FFI bitfield size and alignment
 checktypes{
   4,	4,	"struct { unsigned a:1; }",
   4,	4,	"struct { unsigned a:1, b:1, c:1; }",
@@ -163,6 +176,7 @@ checktypes{
   1,	1,	"struct { char a:1; _Bool b:1; }",
   1,	1,	"struct { char a:1; signed char b:1; unsigned char c:1; }",
 }
+end
 
 -- NYI: bit fields > 32 bit
 -- local L = ffi.alignof("struct { long long a; }")
@@ -170,7 +184,7 @@ checktypes{
 --   L,	L,	"struct { long long a:1; }",
 -- }
 
--- Bit field packing.
+do --- Bit field packing.
 checktypes{
   1,	1,	"struct { _Bool a:1, b:1, c:1; }",
   4,	4,	"struct { short a:9; int b:9; char c; }",
@@ -197,8 +211,9 @@ checktypes{
   6,	2,	"struct __attribute__((packed)) { _Bool a:1; int b __attribute((aligned(2))); }",
   6,	2,	"struct __attribute__((packed)) { _Bool a:1; int b __attribute((aligned(2))) __attribute((packed)); }",
 }
+end
 
-do
+do --- #pragma pack
   ffi.cdef[[
     struct foo_packorig { char a; int b; short c; };
     #pragma pack(1)
@@ -236,7 +251,7 @@ do
   assert(ffi.sizeof("struct foo_packpop2") == 12)
 end
 
-do
+do --- Alignment attributes
   ffi.cdef[[
     #pragma pack(2)
     struct foo_packalign8 {
diff --git a/test/lib/ffi/ffi_tabov.lua b/test/lib/ffi/ffi_tabov.lua
index ba62196..fff3cd2 100644
--- a/test/lib/ffi/ffi_tabov.lua
+++ b/test/lib/ffi/ffi_tabov.lua
@@ -2,6 +2,7 @@ local ffi = require("ffi")
 
 local last = 0
 
+do --- FFI table overflow
 assert(pcall(function()
   for i=1,65536 do
     last = i
@@ -10,3 +11,5 @@ assert(pcall(function()
 end) == false)
 
 assert(last > 20000)
+collectgarbage()
+end
diff --git a/test/lib/ffi/index b/test/lib/ffi/index
index 59e36dd..6727113 100644
--- a/test/lib/ffi/index
+++ b/test/lib/ffi/index
@@ -10,3 +10,20 @@ jit_struct.lua
 meta_tostring.lua
 redir.lua
 type_punning.lua
+ffi_bitfield.lua +ffi
+ffi_arith_ptr.lua +ffi
+ffi_callback.lua +ffi
+ffi_jit_arith.lua +ffi
+ffi_call.lua +ffi
+ffi_const.lua +ffi
+ffi_convert.lua +ffi
+ffi_enum.lua +ffi
+ffi_jit_conv.lua +ffi
+ffi_lex_number.lua +ffi
+ffi_metatype.lua +ffi
+ffi_new.lua +ffi
+ffi_parse_array.lua +ffi
+ffi_parse_basic.lua +ffi
+ffi_jit_call.lua +ffi
+ffi_parse_struct.lua +ffi
+ffi_parse_cdef.lua +ffi
diff --git a/test/misc/alias_alloc.lua b/test/misc/alias_alloc.lua
index 02fe618..94d46a4 100644
--- a/test/misc/alias_alloc.lua
+++ b/test/misc/alias_alloc.lua
@@ -1,5 +1,5 @@
 
-do
+do --- Alias analysis 1
   local t = {1}
   local x
   for i=1,100 do
@@ -10,7 +10,7 @@ do
   assert(x == 100 and t[1] == 100)
 end
 
-do
+do --- Alias analysis 2
   local t = {1}
   local x,y
   for i=1,100 do
@@ -22,7 +22,7 @@ do
   assert(x == 100 and y == 101)
 end
 
-do
+do --- Alias analysis 3
   local mt = {}
   local t = setmetatable({}, mt)
   local x
@@ -33,16 +33,14 @@ do
   end
 end
 
--- See also sink_alloc.lua
-do
+do --- See also sink_alloc.lua
   local x,k={1,2},{3,4}
   for i=1,100 do x = {x[1]+k[1], x[2]+k[2]} end
   assert(x[1] == 301)
   assert(x[2] == 402)
 end
 
--- FLOAD for tab.asize/tab.array crossing NEWREF.
-do
+do --- FLOAD for tab.asize/tab.array crossing NEWREF.
   local t = {1}
   for i=1,100 do
     local v = {}
diff --git a/test/misc/api_call.lua b/test/misc/api_call.lua
index 7dbd5e4..a5712c7 100644
--- a/test/misc/api_call.lua
+++ b/test/misc/api_call.lua
@@ -57,19 +57,10 @@ local function test_adjust_results(testfunc)
   ck(cc(-1, retva, 1, 2), 1, 2)
 end
 
-test_adjust_results(ctest.call)
-test_adjust_results(ctest.pcall_err)
-
-
 local function gcshrink()
   for i=1,10 do collectgarbage() end
 end
 
-assert(select('#', ctest.call(2000, gcshrink)) == 2000)
-gcshrink()
-assert(select('#', ctest.call(7000, gcshrink)) == 7000)
-gcshrink()
-
 local function test_yield(resume, yield)
   local function inpcall()
     ck(pack(yield(6, 7)), 18, 19)
@@ -91,8 +82,24 @@ local function test_yield(resume, yield)
   assert(resume(co) == false)
 end
 
-test_yield(coroutine.resume, coroutine.yield)
-test_yield(ctest.resume, coroutine.yield)
-test_yield(coroutine.resume, ctest.yield)
-test_yield(ctest.resume, ctest.yield)
+
+do --- C API call 1
+  test_adjust_results(ctest.call)
+  test_adjust_results(ctest.pcall_err)
+end
+
+
+do --- C API functions
+  assert(select('#', ctest.call(2000, gcshrink)) == 2000)
+  gcshrink()
+  assert(select('#', ctest.call(7000, gcshrink)) == 7000)
+  gcshrink()
+end
+
+do --- C API and coroutines
+  test_yield(coroutine.resume, coroutine.yield)
+  test_yield(ctest.resume, coroutine.yield)
+  test_yield(coroutine.resume, ctest.yield)
+  test_yield(ctest.resume, ctest.yield)
+end
 
diff --git a/test/misc/catch_wrap.lua b/test/misc/catch_wrap.lua
index 7f656bc..d03f5a1 100644
--- a/test/misc/catch_wrap.lua
+++ b/test/misc/catch_wrap.lua
@@ -1,31 +1,31 @@
 
 local cp = require("cpptest")
 cp.wrapon()
+local unwind
 
-do
+do --- C API wrap 1
   local a, b = pcall(cp.catch, function() return "x" end)
   assert(a == true and b == "x")
 end
 
-do
+do --- C API wrap 2
   local a, b = pcall(function() cp.throw("foo") end)
   assert(a == false and b == "foo")
 end
 
-local unwind
-do
+do --- C API wrap 3
   local a, b = pcall(cp.catch, function() cp.throw("foo") end)
   unwind = a
   assert((a == false and b == "foo") or (a == true and b == "catch ..."))
 end
 
-do
+do --- C API wrap 4
   local st = cp.alloc(function() return cp.isalloc() end)
   assert(st == true)
   assert(cp.isalloc() == false)
 end
 
-do
+do --- C API wrap 5
   local a, b = pcall(cp.alloc, function()
     assert(cp.isalloc() == true)
     return "foo", cp.throw
@@ -34,7 +34,7 @@ do
   assert(cp.isalloc() == false)
 end
 
-do
+do --- C API wrap 6
   local a, b = pcall(cp.alloc, function()
     assert(cp.isalloc() == true)
     return "foo", error
@@ -43,3 +43,6 @@ do
   if unwind then assert(cp.isalloc() == false) end
 end
 
+do --- C API unwrap
+  cp.wrapoff()
+end
diff --git a/test/misc/coro_traceback.lua b/test/misc/coro_traceback.lua
index 2676d2c..8453da5 100644
--- a/test/misc/coro_traceback.lua
+++ b/test/misc/coro_traceback.lua
@@ -1,8 +1,9 @@
-
-local co = coroutine.create(function()
-  local x = nil
-  local y = x.x
-end)
-assert(coroutine.resume(co) == false)
-debug.traceback(co)
+do --- debug.traceback doesn't crash on a dead coroutine
+  local co = coroutine.create(function()
+    local x = nil
+    local y = x.x
+  end)
+  assert(coroutine.resume(co) == false)
+  debug.traceback(co)
+end
 
diff --git a/test/misc/coro_yield.lua b/test/misc/coro_yield.lua
index ae3206e..0d066ee 100644
--- a/test/misc/coro_yield.lua
+++ b/test/misc/coro_yield.lua
@@ -3,8 +3,7 @@ local wrap = coroutine.wrap
 local resume = coroutine.resume
 local yield = coroutine.yield
 
--- Test stack overflow handling on return from coroutine.
-do
+do --- Test stack overflow handling on return from coroutine 1.
   wrap(function()
     local co = create(function()
       yield(string.byte(string.rep(" ", 100), 1, 100))
@@ -13,7 +12,7 @@ do
   end)()
 end
 
-do
+do --- Coroutine yield test 1
   wrap(function()
     local f = wrap(function()
       yield(string.byte(string.rep(" ", 100), 1, 100))
@@ -22,7 +21,7 @@ do
   end)()
 end
 
-do
+do --- Coroutine yield test 2
   local function cogen(x)
     return wrap(function(n) repeat x = x+n; n = yield(x) until false end),
 	   wrap(function(n) repeat x = x*n; n = yield(x) until false end)
@@ -33,7 +32,7 @@ do
   assert(d(b(c(a(d(b(c(a(1)))))))) == 168428160)
 end
 
-do
+do --- Coroutine yield test 3
   local function verify(what, expect, ...)
     local got = {...}
     for i=1,100 do
@@ -59,7 +58,7 @@ do
   verify("resume end", { true, "end" }, resume(co, "again"))
 end
 
-do
+do --- Coroutine yield test 4
   local function verify(expect, func, ...)
     local co = create(func)
     for i=1,100 do
diff --git a/test/test.lua b/test/test.lua
index b064eff..d2aea07 100644
--- a/test/test.lua
+++ b/test/test.lua
@@ -7,6 +7,9 @@ local dirsep = package.config:match"^(.-)\n"
 local own_file = debug.getinfo(1, "S").source:match"^@(.*)" or arg[0]
 local own_dir = own_file:match("^.*[/".. dirsep .."]")
 
+local ctest = require("ctest")
+local cpptest = require("cpptest")
+
 local function default_tags()
   local tags = {}
   
@@ -178,6 +181,7 @@ end
 
 local function scan_tests(path, opts)
   if path:sub(-4, -4) == "." then
+    assert(path:sub(-4, -1) == ".lua")
     local f = assert(io_open(path, "rb"))
     local contents = f:read"*a"
     f:close()
@@ -297,8 +301,11 @@ local function append_tree_to_plan(test_tree, opts, plan, prefix)
 end
 
 local function seal_globals()
+  compat52 = table.pack and true or false
   local sealed_mt = {__newindex = function()
     error("Tests should not mutate global state", 3)
+  end, __index = function(x, y)
+    --print(("Tests should not use undefined globals %q%q"):format(x, y))
   end}
   local function seal(t)
     if getmetatable(t) then return end
@@ -405,8 +412,8 @@ local opts = parse_args{...}
 if not opts then
   return
 end
-seal_globals()
 check_package_path()
+seal_globals()
 local test_tree = scan_tests(opts.root or own_dir or "", opts)
 local plan = append_tree_to_plan(test_tree, opts, {}, "")
 plan = mutate_plan(plan, opts)