From 3bd8e8cd3c411df29d8c1c28bd6f0b8434e8f1ba Mon Sep 17 00:00:00 2001
From: Federico Cecchetto <fedecek3@gmail.com>
Date: Tue, 30 Aug 2022 21:47:29 +0200
Subject: [PATCH] Better gsc link errors

---
 src/client/component/gsc.cpp       | 75 ++++++++++++++++++++++++++++--
 src/client/component/scripting.cpp | 22 ++++-----
 src/client/component/scripting.hpp |  1 +
 3 files changed, 84 insertions(+), 14 deletions(-)

diff --git a/src/client/component/gsc.cpp b/src/client/component/gsc.cpp
index c094eddb..0b7c6ccb 100644
--- a/src/client/component/gsc.cpp
+++ b/src/client/component/gsc.cpp
@@ -334,10 +334,70 @@ namespace gsc
 			return utils::hook::invoke<void*>(0x140614670, a1);
 		}
 
-		void unknown_function_stub()
+		std::string unknown_function_error{};
+		void get_unknown_function_error(const char* code_pos)
 		{
-			game::Com_Error(game::ERR_DROP, "LinkFile: unknown function in script '%s.gsc'", 
-				scripting::current_file.data());
+			const auto function = find_function(code_pos);
+			if (function.has_value())
+			{
+				const auto& pos = function.value();
+				unknown_function_error = utils::string::va(
+					"while processing function '%s' in script '%s':\nunknown script '%s'",
+					pos.first.data(), pos.second.data(), scripting::current_file.data()
+				);
+			}
+			else
+			{
+				unknown_function_error = utils::string::va(
+					"unknown script '%s'",
+					scripting::current_file.data()
+				);
+			}
+		}
+
+		unsigned int current_filename{};
+		std::string get_filename_name()
+		{
+			const auto filename_str = game::SL_ConvertToString(
+				static_cast<game::scr_string_t>(current_filename));
+			const auto id = std::atoi(filename_str);
+			if (id == 0)
+			{
+				return filename_str;
+			}
+
+			return scripting::get_token_single(id);
+		}
+
+
+		void get_unknown_function_error(unsigned int thread_name)
+		{
+			const auto filename = get_filename_name();
+			const auto name = scripting::get_token_single(thread_name);
+
+			unknown_function_error = utils::string::va(
+				"while processing script '%s':\nunknown function '%s::%s'",
+				scripting::current_file.data(), filename.data(), name.data()
+			);
+		}
+
+		void unknown_function_stub(const char* code_pos)
+		{
+			get_unknown_function_error(code_pos);
+			game::Com_Error(game::ERR_DROP, "script link error\n%s", 
+				unknown_function_error.data());
+		}
+
+		unsigned int find_variable_stub(unsigned int parent_id, unsigned int thread_name)
+		{
+			const auto res = game::FindVariable(parent_id, thread_name);
+			if (!res)
+			{
+				get_unknown_function_error(thread_name);
+				game::Com_Error(game::ERR_DROP, "script link error\n%s",
+					unknown_function_error.data());
+			}
+			return res;
 		}
 
 		void register_gsc_functions_stub(void* a1, void* a2)
@@ -412,6 +472,13 @@ namespace gsc
 				execute_custom_function(function);
 			}
 		}
+
+		utils::hook::detour scr_emit_function_hook;
+		void scr_emit_function_stub(unsigned int filename, unsigned int thread_name, char* code_pos)
+		{
+			current_filename = filename;
+			scr_emit_function_hook.invoke<void>(filename, thread_name, code_pos);
+		}
 	}
 
 	game::ScriptFile* find_script(game::XAssetType /*type*/, const char* name, int /*allow_create_default*/)
@@ -475,6 +542,8 @@ namespace gsc
 
 			utils::hook::call(0x1405BC583, unknown_function_stub);
 			utils::hook::call(0x1405BC5CF, unknown_function_stub);
+			utils::hook::call(0x1405BC6BA, find_variable_stub);
+			scr_emit_function_hook.create(0x1405BC5E0, scr_emit_function_stub);
 
 			utils::hook::call(0x1405BCBAB, register_gsc_functions_stub);
 			utils::hook::set<uint32_t>(0x1405BC7BC, 0x1000); // change builtin func count
diff --git a/src/client/component/scripting.cpp b/src/client/component/scripting.cpp
index ab336291..267b37e0 100644
--- a/src/client/component/scripting.cpp
+++ b/src/client/component/scripting.cpp
@@ -165,22 +165,12 @@ namespace scripting
 			return result;
 		}
 
-		std::string get_token_single(unsigned int id)
-		{
-			if (canonical_string_table.find(id) != canonical_string_table.end())
-			{
-				return canonical_string_table[id];
-			}
-
-			return scripting::find_token_single(id);
-		}
-
 		void add_function_sort(unsigned int id, const char* pos)
 		{
 			std::string filename = current_file;
 			if (current_file_id)
 			{
-				filename = get_token_single(current_file_id);
+				filename = scripting::get_token_single(current_file_id);
 			}
 
 			if (script_function_table_sort.find(filename) == script_function_table_sort.end())
@@ -289,6 +279,16 @@ namespace scripting
 		}
 	}
 
+	std::string get_token_single(unsigned int id)
+	{
+		if (canonical_string_table.find(id) != canonical_string_table.end())
+		{
+			return canonical_string_table[id];
+		}
+
+		return scripting::find_token_single(id);
+	}
+
 	void on_shutdown(const std::function<void(bool)>& callback)
 	{
 		shutdown_callbacks.push_back(callback);
diff --git a/src/client/component/scripting.hpp b/src/client/component/scripting.hpp
index b95cc62d..bf6d90c7 100644
--- a/src/client/component/scripting.hpp
+++ b/src/client/component/scripting.hpp
@@ -16,4 +16,5 @@ namespace scripting
 
 	void on_shutdown(const std::function<void(bool)>& callback);
 	std::optional<std::string> get_canonical_string(const unsigned int id);
+	std::string get_token_single(unsigned int id);
 }
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