Make lanes.gen stricter on base libraries

5 files changed, 60 insertions, 27 deletions

diff --git a/src/lanes.cpp b/src/lanes.cpp
index cab5944..39723ca 100644
--- a/src/lanes.cpp
+++ b/src/lanes.cpp
@@ -636,6 +636,7 @@ namespace {
             { "set_thread_priority", LG_set_thread_priority },
             { "set_thread_affinity", LG_set_thread_affinity },
             { "sleep", LG_sleep },
+            { "supported_libs", state::LG_supported_libs },
             { "wakeup_conv", LG_wakeup_conv },
             { nullptr, nullptr }
         };
diff --git a/src/lanes.lua b/src/lanes.lua
index 90f9cd2..6a4f149 100644
--- a/src/lanes.lua
+++ b/src/lanes.lua
@@ -222,23 +222,25 @@ end
 
 local valid_libs =
 {
-    ["package"] = true,
-    ["table"] = true,
+    ["base"] = true,
+    ["bit"] = true,
+    ["bit32"] = true,
+    ["coroutine"] = true,
+    ["debug"] = true,
+    ["ffi"] = true,
     ["io"] = true,
+    ["jit"] = true,
+    ["math"] = true,
     ["os"] = true,
+    ["package"] = true,
     ["string"] = true,
-    ["math"] = true,
-    ["debug"] = true,
-    ["bit32"] = true, -- Lua 5.2 only, ignored silently under 5.1
-    ["utf8"] = true, -- Lua 5.3 only, ignored silently under 5.1 and 5.2
-    ["bit"] = true, -- LuaJIT only, ignored silently under PUC-Lua
-    ["jit"] = true, -- LuaJIT only, ignored silently under PUC-Lua
-    ["ffi"] = true, -- LuaJIT only, ignored silently under PUC-Lua
+    ["table"] = true,
+    ["utf8"] = true,
     --
-    ["base"] = true,
-    ["coroutine"] = true, -- part of "base" in Lua 5.1
     ["lanes.core"] = true
 }
+-- same structure, but contains only the libraries that the current Lua flavor actually supports
+local supported_libs
 
 -- #################################################################################################
 
@@ -375,14 +377,17 @@ local gen = function(...)
             error "Libs specification '*' must be used alone"
         end
         local found = {}
-        for s in string_gmatch(libs, "[%a%d.]+") do
+        -- accept lib identifiers followed by an optional question mark
+        for s, question in string_gmatch(libs, "([%a%d.]+)(%??)") do
             if not valid_libs[s] then
-                error("Bad library name: " .. s, 2)
-            else
-                found[s] = (found[s] or 0) + 1
-                if found[s] > 1 then
-                    error("Libs specification contains '" .. s .. "' more than once", 2)
-                end
+                error("Bad library name: " .. string_format("%q", tostring(s)), 2)
+            end
+            if question == '' and not supported_libs[s] then
+                error("Unsupported library: " .. string_format("%q", tostring(s)), 2)
+            end
+            found[s] = (found[s] or 0) + 1
+            if found[s] > 1 then
+                error("Libs specification contains " .. string_format("%q", tostring(s)) .. " more than once", 2)
             end
         end
     end
@@ -810,6 +815,11 @@ local configure = function(settings_)
     lanes.configure = function() return lanes end -- no need to configure anything again
 
     -- now we can configure Lanes core
+
+
+
+
+
     local settings = core.configure and core.configure(params_checker(settings_)) or core.settings
 
     --
@@ -825,6 +835,7 @@ local configure = function(settings_)
     -- avoid pulling the whole core module as upvalue when cancel_error is enough
     -- these are locals declared above, that we need to set prior to calling configure_timers()
     cancel_error = assert(core.cancel_error)
+    supported_libs = assert(core.supported_libs())
     timerLinda = assert(core.timerLinda)
 
     if settings.with_timers then
diff --git a/src/state.cpp b/src/state.cpp
index 9cd7343..b50d135 100644
--- a/src/state.cpp
+++ b/src/state.cpp
@@ -57,32 +57,37 @@ namespace {
 
     namespace local {
         static luaL_Reg const sLibs[] = {
-            { "base", nullptr }, // ignore "base" (already acquired it)
+            { "base", nullptr }, // ignore "base" is always valid, but opened separately
+
+#if LUA_VERSION_NUM == 502 || LUA_VERSION_NUM == 503
+            { LUA_BITLIBNAME, luaopen_bit32 }, // active in Lua 5.2, replaced with an error-throwing loader in Lua 5.3, gone after.
+#endif // LUA_VERSION_NUM == 502 || LUA_VERSION_NUM == 503
+
 #if LUA_VERSION_NUM >= 502
-#ifdef luaopen_bit32
-            { LUA_BITLIBNAME, luaopen_bit32 },
-#endif
             { LUA_COLIBNAME, luaopen_coroutine }, // Lua 5.2: coroutine is no longer a part of base!
-#else // LUA_VERSION_NUM
-            { LUA_COLIBNAME, nullptr }, // Lua 5.1: part of base package
 #endif // LUA_VERSION_NUM
+
             { LUA_DBLIBNAME, luaopen_debug },
+
 #ifndef PLATFORM_XBOX // no os/io libs on xbox
             { LUA_IOLIBNAME, luaopen_io },
             { LUA_OSLIBNAME, luaopen_os },
 #endif // PLATFORM_XBOX
+
             { LUA_LOADLIBNAME, luaopen_package },
             { LUA_MATHLIBNAME, luaopen_math },
             { LUA_STRLIBNAME, luaopen_string },
             { LUA_TABLIBNAME, luaopen_table },
+
 #if LUA_VERSION_NUM >= 503
             { LUA_UTF8LIBNAME, luaopen_utf8 },
-#endif
+#endif // LUA_VERSION_NUM >= 503
+
 #if LUAJIT_FLAVOR() != 0 // building against LuaJIT headers, add some LuaJIT-specific libs
             { LUA_BITLIBNAME, luaopen_bit },
             { LUA_FFILIBNAME, luaopen_ffi },
             { LUA_JITLIBNAME, luaopen_jit },
-#endif // LUAJIT_FLAVOR()
+#endif // LUAJIT_FLAVOR() != 0
 
             { kLanesCoreLibName, require_lanes_core } // So that we can open it like any base library (possible since we have access to the init function)
         };
@@ -312,6 +317,21 @@ namespace state {
     }
 
     // #############################################################################################
+
+    // for internal use only: tell lanes.lua which base libraries are actually supported internally
+    LUAG_FUNC(supported_libs)
+    {
+        STACK_CHECK_START_REL(L_, 0);
+        lua_newtable(L_);                                                                          // L_: out
+        for (luaL_Reg const& _entry : local::sLibs) {
+            lua_pushboolean(L_, 1);                                                                // L_: out true
+            luaG_setfield(L_, -2, std::string_view{ _entry.name }); // out[name] = true            // L_: out
+        }
+        STACK_CHECK(L_, 1);
+        return 1;
+    }
+
+    // #############################################################################################
     // #############################################################################################
 } // namespace state
 // #################################################################################################
diff --git a/src/state.h b/src/state.h
index f809d50..a6bb43b 100644
--- a/src/state.h
+++ b/src/state.h
@@ -10,4 +10,5 @@ class Universe;
 namespace state {
     [[nodiscard]] lua_State* CreateState(Universe* U_, lua_State* from_, std::string_view const& hint_);
     [[nodiscard]] lua_State* NewLaneState(Universe* U_, SourceState from_, std::optional<std::string_view> const& libs_);
+    LUAG_FUNC(supported_libs);
 } // namespace state
diff --git a/src/universe.cpp b/src/universe.cpp
index 0dc5646..1cb4fd0 100644
--- a/src/universe.cpp
+++ b/src/universe.cpp
@@ -111,7 +111,7 @@ void Universe::callOnStateCreate(lua_State* const L_, lua_State* const from_, Lo
     std::string_view const _stateType{ mode_ == LookupMode::LaneBody ? "lane" : "keeper" };
     luaG_pushstring(L_, _stateType);                                                               // L_: on_state_create() "<type>"
     if (lua_pcall(L_, 1, 0, 0) != LUA_OK) {
-        raise_luaL_error(from_, "%s failed: \"%s\"", kOnStateCreate.data(), lua_isstring(L_, -1) ? luaG_tostring(L_, -1).data() : luaG_typename(L_, -1).data());
+        raise_luaL_error(from_, "%s failed in %s: \"%s\"", kOnStateCreate.data(), _stateType.data(), lua_isstring(L_, -1) ? luaG_tostring(L_, -1).data() : luaG_typename(L_, -1).data());
     }
     STACK_CHECK(L_, 0);
 }