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Work around LuaJIT issues on aarch64 (#9614)
- Move the text segment below the 47-bit limit, needed for script_exception_wrapper which must be lightuserdata
- Replace CUSTOM_RIDX_SCRIPTAPI with full userdata
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sfan5 committed Apr 8, 2020
1 parent de73f98 commit 659245a
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Showing 5 changed files with 33 additions and 4 deletions.
10 changes: 8 additions & 2 deletions src/CMakeLists.txt
Expand Up @@ -661,7 +661,7 @@ endif()

# Set some optimizations and tweaks

include(CheckCXXCompilerFlag)
include(CheckCSourceCompiles)

if(MSVC)
# Visual Studio
Expand Down Expand Up @@ -695,13 +695,19 @@ else()
else()
set(RELEASE_WARNING_FLAGS "")
endif()

if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
set(WARNING_FLAGS "${WARNING_FLAGS} -Wsign-compare")
endif()

if(APPLE AND USE_LUAJIT)
# required per http://luajit.org/install.html
SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -pagezero_size 10000 -image_base 100000000")
elseif(UNIX AND USE_LUAJIT)
check_c_source_compiles("#ifndef __aarch64__\n#error\n#endif\nint main(){}" IS_AARCH64)
if(IS_AARCH64)
# Move text segment below LuaJIT's 47-bit limit (see issue #9367)
SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-Ttext-segment=0x200000000")
endif()
endif()

if(MINGW)
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9 changes: 9 additions & 0 deletions src/script/common/c_internal.h
Expand Up @@ -54,6 +54,15 @@ extern "C" {
#define CUSTOM_RIDX_CURRENT_MOD_NAME (CUSTOM_RIDX_BASE + 2)
#define CUSTOM_RIDX_BACKTRACE (CUSTOM_RIDX_BASE + 3)

// Determine if CUSTOM_RIDX_SCRIPTAPI will hold a light or full userdata
#if defined(__aarch64__) && USE_LUAJIT
/* LuaJIT has a 47-bit limit for lightuserdata on this platform and we cannot
* assume that the ScriptApi class was allocated at a fitting address. */
#define INDIRECT_SCRIPTAPI_RIDX 1
#else
#define INDIRECT_SCRIPTAPI_RIDX 0
#endif

// Pushes the error handler onto the stack and returns its index
#define PUSH_ERROR_HANDLER(L) \
(lua_rawgeti((L), LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE), lua_gettop((L)))
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4 changes: 4 additions & 0 deletions src/script/cpp_api/s_base.cpp
Expand Up @@ -90,7 +90,11 @@ ScriptApiBase::ScriptApiBase(ScriptingType type):
luaL_openlibs(m_luastack);

// Make the ScriptApiBase* accessible to ModApiBase
#if INDIRECT_SCRIPTAPI_RIDX
*(void **)(lua_newuserdata(m_luastack, sizeof(void *))) = this;
#else
lua_pushlightuserdata(m_luastack, this);
#endif
lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);

// Add and save an error handler
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7 changes: 6 additions & 1 deletion src/script/cpp_api/s_security.cpp
Expand Up @@ -499,7 +499,12 @@ bool ScriptApiSecurity::checkPath(lua_State *L, const char *path,

// Get server from registry
lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
ScriptApiBase *script = (ScriptApiBase *) lua_touserdata(L, -1);
ScriptApiBase *script;
#if INDIRECT_SCRIPTAPI_RIDX
script = (ScriptApiBase *) *(void**)(lua_touserdata(L, -1));
#else
script = (ScriptApiBase *) lua_touserdata(L, -1);
#endif
lua_pop(L, 1);
const IGameDef *gamedef = script->getGameDef();
if (!gamedef)
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7 changes: 6 additions & 1 deletion src/script/lua_api/l_base.cpp
Expand Up @@ -30,7 +30,12 @@ ScriptApiBase *ModApiBase::getScriptApiBase(lua_State *L)
{
// Get server from registry
lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
ScriptApiBase *sapi_ptr = (ScriptApiBase*) lua_touserdata(L, -1);
ScriptApiBase *sapi_ptr;
#if INDIRECT_SCRIPTAPI_RIDX
sapi_ptr = (ScriptApiBase*) *(void**)(lua_touserdata(L, -1));
#else
sapi_ptr = (ScriptApiBase*) lua_touserdata(L, -1);
#endif
lua_pop(L, 1);
return sapi_ptr;
}
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