diff options
Diffstat (limited to 'tex/context/base/trac-pro.lua')
| -rw-r--r-- | tex/context/base/trac-pro.lua | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/tex/context/base/trac-pro.lua b/tex/context/base/trac-pro.lua new file mode 100644 index 000000000..bfcd71138 --- /dev/null +++ b/tex/context/base/trac-pro.lua @@ -0,0 +1,207 @@ +if not modules then modules = { } end modules ['trac-pro'] = { + version = 1.001, + comment = "companion to luat-lib.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +local getmetatable, setmetatable, rawset, type = getmetatable, setmetatable, rawset, type + +-- The protection implemented here is probably not that tight but good enough to catch +-- problems due to naive usage. +-- +-- There's a more extensive version (trac-xxx.lua) that supports nesting. +-- +-- This will change when we have _ENV in lua 5.2+ + +local trace_namespaces = false trackers.register("system.namespaces", function(v) trace_namespaces = v end) + +local report_system = logs.new("system") + +namespaces = { } + +local registered = { } + +local function report_index(k,name) + if trace_namespaces then + report_system("reference to '%s' in protected namespace '%s', %s",k,name,debug.traceback()) + else + report_system("reference to '%s' in protected namespace '%s'",k,name) + end +end + +local function report_newindex(k,name) + if trace_namespaces then + report_system("assignment to '%s' in protected namespace '%s', %s",k,name,debug.traceback()) + else + report_system("assignment to '%s' in protected namespace '%s'",k,name) + end +end + +local function register(name) + local data = name == "global" and _G or _G[name] + if not data then + return -- error + end + registered[name] = data + local m = getmetatable(data) + if not m then + m = { } + setmetatable(data,m) + end + local index, newindex = { }, { } + m.__saved__index = m.__index + m.__no__index = function(t,k) + if not index[k] then + index[k] = true + report_index(k,name) + end + return nil + end + m.__saved__newindex = m.__newindex + m.__no__newindex = function(t,k,v) + if not newindex[k] then + newindex[k] = true + report_newindex(k,name) + end + rawset(t,k,v) + end + m.__protection__depth = 0 +end + +local function private(name) -- maybe save name + local data = registered[name] + if not data then + data = _G[name] + if not data then + data = { } + _G[name] = data + end + register(name) + end + return data +end + +local function protect(name) + local data = registered[name] + if not data then + return + end + local m = getmetatable(data) + local pd = m.__protection__depth + if pd > 0 then + m.__protection__depth = pd + 1 + else + m.__save_d_index, m.__saved__newindex = m.__index, m.__newindex + m.__index, m.__newindex = m.__no__index, m.__no__newindex + m.__protection__depth = 1 + end +end + +local function unprotect(name) + local data = registered[name] + if not data then + return + end + local m = getmetatable(data) + local pd = m.__protection__depth + if pd > 1 then + m.__protection__depth = pd - 1 + else + m.__index, m.__newindex = m.__saved__index, m.__saved__newindex + m.__protection__depth = 0 + end +end + +local function protectall() + for name, _ in next, registered do + if name ~= "global" then + protect(name) + end + end +end + +local function unprotectall() + for name, _ in next, registered do + if name ~= "global" then + unprotect(name) + end + end +end + +namespaces.register = register -- register when defined +namespaces.private = private -- allocate and register if needed +namespaces.protect = protect +namespaces.unprotect = unprotect +namespaces.protectall = protectall +namespaces.unprotectall = unprotectall + +namespaces.private("namespaces") registered = { } register("global") -- unreachable + +directives.register("system.protect", function(v) + if v then + protectall() + else + unprotectall() + end +end) + +directives.register("system.checkglobals", function(v) + if v then + report_system("enabling global namespace guard") + protect("global") + else + report_system("disabling global namespace guard") + unprotect("global") + end +end) + +-- dummy section (will go to luat-dum.lua) + +--~ if not namespaces.private then +--~ -- somewhat protected +--~ local registered = { } +--~ function namespaces.private(name) +--~ local data = registered[name] +--~ if data then +--~ return data +--~ end +--~ local data = _G[name] +--~ if not data then +--~ data = { } +--~ _G[name] = data +--~ end +--~ registered[name] = data +--~ return data +--~ end +--~ function namespaces.protectall(list) +--~ for name, data in next, list or registered do +--~ setmetatable(data, { __newindex = function() print(string.format("table %s is protected",name)) end }) +--~ end +--~ end +--~ namespaces.protectall { namespaces = namespaces } +--~ end + +--~ directives.enable("system.checkglobals") + +--~ namespaces.register("resolvers","trackers") +--~ namespaces.protect("resolvers") +--~ namespaces.protect("resolvers") +--~ namespaces.protect("resolvers") +--~ namespaces.unprotect("resolvers") +--~ namespaces.unprotect("resolvers") +--~ namespaces.unprotect("resolvers") +--~ namespaces.protect("trackers") + +--~ resolvers.x = true +--~ resolvers.y = true +--~ trackers.a = "" +--~ resolvers.z = true +--~ oeps = { } + +--~ resolvers = namespaces.private("resolvers") +--~ fonts = namespaces.private("fonts") +--~ directives.enable("system.protect") +--~ namespaces.protectall() +--~ resolvers.xx = { } |