verbose_error improvements

* Fix a stack overflow when copying large tables with verbose_errors
option enabled
* Support for integer formatting in verbose errors

1 files changed, 55 insertions, 36 deletions

diff --git a/src/tools.c b/src/tools.c
index 9403fd6..59037e6 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -1480,6 +1480,58 @@ static void push_cached_func( struct s_Universe* U, lua_State* L2, uint_t L2_cac
         }
 }
 
+static void inter_copy_keyvaluepair( struct s_Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, enum e_vt vt, enum eLookupMode mode_, char const* upName_)
+{
+        uint_t val_i = lua_gettop( L);
+        uint_t key_i = val_i - 1;
+
+        // Only basic key types are copied over; others ignored
+        if( inter_copy_one_( U, L2, 0 /*key*/, L, key_i, VT_KEY, mode_, upName_))
+        {
+                char* valPath = (char*) upName_;
+                if( U->verboseErrors)
+                {
+                        // for debug purposes, let's try to build a useful name
+                        if( lua_type( L, key_i) == LUA_TSTRING)
+                        {
+                                char const* key = lua_tostring( L, key_i);
+                                size_t const keyRawLen = lua_rawlen( L, key_i);
+                                size_t const bufLen = strlen( upName_) + keyRawLen + 2;
+                                valPath = (char*) alloca( bufLen);
+                                sprintf( valPath, "%s.%*s", upName_, (int) keyRawLen, key);
+                                key = NULL;
+                        }
+#if defined LUA_LNUM || LUA_VERSION_NUM >= 503
+                        else if( lua_isinteger( L, key_i))
+                        {
+                                lua_Integer key = lua_tointeger( L, key_i);
+                                valPath = (char*) alloca( strlen( upName_) + 32 + 3);
+                                sprintf( valPath, "%s[" LUA_INTEGER_FMT "]", upName_, key);
+                        }
+#endif // defined LUA_LNUM || LUA_VERSION_NUM >= 503
+                        else if( lua_type( L, key_i) == LUA_TNUMBER)
+                        {
+                                lua_Number key = lua_tonumber( L, key_i);
+                                valPath = (char*) alloca( strlen( upName_) + 32 + 3);
+                                sprintf( valPath, "%s[" LUA_NUMBER_FMT "]", upName_, key);
+                        }
+                }
+                /*
+                * Contents of metatables are copied with cache checking;
+                * important to detect loops.
+                */
+                if( inter_copy_one_( U, L2, L2_cache_i, L, val_i, VT_NORMAL, mode_, valPath))
+                {
+                        ASSERT_L( lua_istable( L2, -3));
+                        lua_rawset( L2, -3);    // add to table (pops key & val)
+                }
+                else
+                {
+                        luaL_error( L, "Unable to copy over type '%s' (in %s)", luaL_typename( L, val_i), (vt == VT_NORMAL) ? "table" : "metatable");
+                }
+        }
+}
+
 /*
 * Copies a value from 'L' state (at index 'i') to 'L2' state. Does not remove
 * the original value.
@@ -1529,7 +1581,7 @@ static bool_t inter_copy_one_( struct s_Universe* U, lua_State* L2, uint_t L2_ca
                         break;
                 }
                 else
-#endif
+#endif // defined LUA_LNUM || LUA_VERSION_NUM >= 503
                 {
                         lua_Number v = lua_tonumber( L, i);
                         DEBUGSPEW_CODE( if( vt == VT_KEY) fprintf( stderr, INDENT_BEGIN "KEY: " LUA_NUMBER_FMT "\n" INDENT_END, v));
@@ -1655,41 +1707,8 @@ static bool_t inter_copy_one_( struct s_Universe* U, lua_State* L2, uint_t L2_ca
                         lua_pushnil( L);    // start iteration
                         while( lua_next( L, i))
                         {
-                                uint_t val_i = lua_gettop( L);
-                                uint_t key_i = val_i - 1;
-
-                                // Only basic key types are copied over; others ignored
-                                if( inter_copy_one_( U, L2, 0 /*key*/, L, key_i, VT_KEY, mode_, upName_))
-                                {
-                                        char* valPath = (char*) upName_;
-                                        if( U->verboseErrors)
-                                        {
-                                                // for debug purposes, let's try to build a useful name
-                                                if( lua_type( L, key_i) == LUA_TSTRING)
-                                                {
-                                                        valPath = (char*) alloca( strlen( upName_) + strlen( lua_tostring( L, key_i)) + 2);
-                                                        sprintf( valPath, "%s.%s", upName_, lua_tostring( L, key_i));
-                                                }
-                                                else if( lua_type( L, key_i) == LUA_TNUMBER)
-                                                {
-                                                        valPath = (char*) alloca( strlen( upName_) + 32 + 3);
-                                                        sprintf( valPath, "%s[" LUA_NUMBER_FMT "]", upName_, lua_tonumber( L, key_i));
-                                                }
-                                        }
-                                        /*
-                                        * Contents of metatables are copied with cache checking;
-                                        * important to detect loops.
-                                        */
-                                        if( inter_copy_one_( U, L2, L2_cache_i, L, val_i, VT_NORMAL, mode_, valPath))
-                                        {
-                                                ASSERT_L( lua_istable( L2, -3));
-                                                lua_rawset( L2, -3);    // add to table (pops key & val)
-                                        }
-                                        else
-                                        {
-                                                luaL_error( L, "Unable to copy over type '%s' (in %s)", luaL_typename( L, val_i), (vt == VT_NORMAL) ? "table" : "metatable");
-                                        }
-                                }
+                                // need a function to prevent overflowing the stack with verboseErrors-induced alloca()
+                                inter_copy_keyvaluepair( U, L2, L2_cache_i, L, vt, mode_, upName_);
                                 lua_pop( L, 1);    // pop value (next round)
                         }
                         STACK_MID( L, 0);