tests/lapi: add bitop tests

The patch adds initial infrastructure for Lua API tests and
changes existed infrastructure for running these tests. The patch
reqires commit "cmake: allow to set a Lua library outside" in
`luzer` project.

The patch adds a fuzzing tests for Lua bitwise operations.
In LuaJIT, these operations are implemented as a Lua functions in
BitOp module [1], that later became a part of LuaJIT.
In PUC Rio Lua, bitwise operations were added since version
5.2 [2] in "bit32" library. In Lua 5.3 the bit32 library has been
deprecated and its operations were replaced by bitwise operations.

1. http://bitop.luajit.org/
2. https://www.lua.org/manual/5.2/manual.html#6.7
3. https://www.lua.org/manual/5.3/manual.html#3.4.2
4. https://www.lua.org/manual/5.3/manual.html#8.2
5. ligurio/luzer@4ce52a6

Author: ligurio

cmake/BuildLua.cmake

@@ -5,6 +5,7 @@ macro(build_lua LUA_VERSION)
     set(LUA_PATCH_PATH ${PROJECT_SOURCE_DIR}/patches/puc-rio-lua.patch)
 
     set(CFLAGS "${CMAKE_C_FLAGS} -fno-omit-frame-pointer")
+    set(CFLAGS "${CMAKE_C_FLAGS} -DLUA_USE_DLOPEN")
     if (ENABLE_LUA_ASSERT)
         set(CFLAGS "${CFLAGS} -DLUAI_ASSERT")
     endif (ENABLE_LUA_ASSERT)
@@ -56,6 +57,9 @@ macro(build_lua LUA_VERSION)
         set(LDFLAGS "${LDFLAGS} -fprofile-instr-generate -fprofile-arcs -fcoverage-mapping -ftest-coverage")
     endif (ENABLE_COV)
 
+    # "relocation R_X86_64_PC32 against symbol `lua_isnumber' can
+    # not be used when making a shared object; recompile with -fPIC".
+    set(CFLAGS "${CFLAGS} -fPIC")
 
     include(ExternalProject)
 

cmake/BuildLuaJIT.cmake

@@ -80,6 +80,9 @@ macro(build_luajit LJ_VERSION)
         set(LDFLAGS "${LDFLAGS} -fprofile-instr-generate -fprofile-arcs -fcoverage-mapping -ftest-coverage")
     endif (ENABLE_COV)
 
+    # "relocation R_X86_64_PC32 against symbol `lua_isnumber' can
+    # not be used when making a shared object; recompile with -fPIC".
+    set(CFLAGS "${CFLAGS} -fPIC")
 
     include(ExternalProject)
 

cmake/BuildLuzer.cmake

@@ -9,6 +9,8 @@ macro(build_luzer)
 
   include(ExternalProject)
 
+  get_target_property(LUA_LIBRARIES_LOCATION ${LUA_LIBRARIES} LOCATION)
+
   ExternalProject_Add(bundled-luzer
       GIT_REPOSITORY https://github.com/ligurio/luzer
       GIT_TAG 649289aa945b7d6c1e2c29edccc83fd3fbe70568
@@ -23,6 +25,10 @@ macro(build_luzer)
               -G ${CMAKE_GENERATOR} ${BENCHMARK_CMAKE_FLAGS}
               -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
               -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+              -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+
+              -DLUA_INCLUDE_DIR=${LUA_INCLUDE_DIR}
+              -DLUA_LIBRARIES=${LUA_LIBRARIES_LOCATION}
       BUILD_COMMAND cd <BINARY_DIR> && ${CMAKE_MAKE_PROGRAM}
       INSTALL_COMMAND ""
       CMAKE_GENERATOR ${CMAKE_GENERATOR}
@@ -34,6 +40,7 @@ macro(build_luzer)
   set_target_properties(luzer-library PROPERTIES
     IMPORTED_LOCATION "${LUZER_LIBRARIES}")
   add_dependencies(luzer-library bundled-luzer)
+  add_dependencies(bundled-luzer bundled-liblua)
 
   set(LUZER_LUA_PATH ${LUZER_DIR}/source/?/init.lua)
   set(LUZER_LUA_PATH ${LUZER_LUA_PATH} PARENT_SCOPE)

tests/CMakeLists.txt

@@ -1,4 +1,2 @@
 add_subdirectory(capi)
-if (ENABLE_BONUS_TESTS)
-  add_subdirectory(lapi)
-endif()
+add_subdirectory(lapi)

tests/lapi/CMakeLists.txt

@@ -0,0 +1,65 @@
+include(BuildLuzer)
+build_luzer()
+include(MakeLuaPath)
+
+if(NOT LUA_EXECUTABLE)
+  message(FATAL_ERROR "${LUA_EXECUTABLE} is not found.")
+endif()
+
+make_lua_path(LUA_CPATH
+  PATHS
+  ${LUZER_LUA_CPATH}
+)
+
+make_lua_path(LUA_PATH
+  PATHS
+  ${LUZER_LUA_PATH}
+  ${CMAKE_CURRENT_SOURCE_DIR}/?.lua
+)
+
+set(DEFAULT_RUNS_NUMBER 5)
+
+string(JOIN " " LIBFUZZER_OPTS
+  -print_final_stats=1
+  -print_pcs=1
+  -reduce_inputs=1
+  -reload=1
+  -report_slow_units=5
+  -runs=$\{RUNS:-${DEFAULT_RUNS_NUMBER}\}
+)
+
+function(create_test)
+  cmake_parse_arguments(
+    FUZZ
+    ""
+    "FILENAME"
+    ""
+    ${ARGN}
+  )
+  get_filename_component(test_name ${FUZZ_FILENAME} NAME_WE)
+  string(REPLACE "_test" "" test_prefix ${test_name})
+  set(dict_path ${PROJECT_SOURCE_DIR}/corpus/${test_prefix}.dict)
+  set(corpus_path ${PROJECT_SOURCE_DIR}/corpus/${test_prefix})
+  if (EXISTS ${dict_path})
+    set(LIBFUZZER_OPTS "${LIBFUZZER_OPTS} -dict=${dict_path}")
+  endif ()
+  if (EXISTS ${corpus_path})
+    set(LIBFUZZER_OPTS "${LIBFUZZER_OPTS} ${corpus_path}")
+  endif ()
+  add_test(NAME ${test_name}
+    COMMAND ${LUA_EXECUTABLE} ${FUZZ_FILENAME} "${LIBFUZZER_OPTS}"
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+  )
+  set_tests_properties(${test_name} PROPERTIES
+    LABELS "lapi"
+    ENVIRONMENT "LUA_PATH=${LUA_PATH};LUA_CPATH=${LUA_CPATH};ASAN_OPTIONS=detect_odr_violation=0"
+    DEPENDS ${LUA_EXECUTABLE} ${LUZER_LIBRARY}
+  )
+endfunction()
+
+message(STATUS "Add Lua API test suite")
+file(GLOB tests LIST_DIRECTORIES false ${CMAKE_CURRENT_SOURCE_DIR} *_test.lua)
+foreach(filename ${tests})
+  get_filename_component(test_name ${filename} NAME_WE)
+  create_test(FILENAME ${filename})
+endforeach()

tests/lapi/bitop_arshift_test.lua

@@ -0,0 +1,30 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+Synopsis: bit32.arshift (x, disp)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+if test_lib.version() ~= "LuaJIT" then
+    os.exit(0)
+end
+
+local bitop = require("bit")
+local arshift = bitop.arshift
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = test_lib.random_number(fdp)
+    local y = test_lib.random_number(fdp)
+    arshift(x, y)
+end
+
+local args = {
+    max_len = 4096,
+    max_total_time = 10,
+    artifact_prefix = "bitop_arshift_",
+}
+luzer.Fuzz(TestOneInput, nil, args)

tests/lapi/bitop_band_test.lua

@@ -0,0 +1,46 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+Wrong code generation for constants in bitwise operations,
+https://github.com/lua/lua/commit/c764ca71a639f5585b5f466bea25dc42b855a4b0
+
+Inconsistent behaviour of bit ops in DUALNUM mode,
+https://github.com/LuaJIT/LuaJIT/issues/1273
+
+Synopsis: bit32.band (...)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local band
+if test_lib.version() == "LuaJIT" then
+    local bitop = require("bit")
+    band = bitop.band
+else
+    band = test_lib.bitwise_op("&")
+end
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = test_lib.random_number(fdp)
+    local y = test_lib.random_number(fdp)
+    local z = test_lib.random_number(fdp)
+
+    assert(band(x, band(y, z)) ==
+           band(band(x, y), z), "x & (y & z) ~= (x & y) & z")
+    assert(band(x, 0) == 0, "x & 0 ~= 0, where x = " .. x)
+
+    -- Broken?
+    -- assert(band(x, 0xffff) == x, "x & 0xFFFF ~= x")
+    -- assert(band(x, y) == band(y, z), "x & y ~= y & x")
+    -- assert(band(x, x) == x, "x & x ~= x, where x = " .. x)
+end
+
+local args = {
+    max_len = 4096,
+    max_total_time = 10,
+    artifact_prefix = "bitop_band_",
+}
+luzer.Fuzz(TestOneInput, nil, args)

tests/lapi/bitop_bnot_test.lua

@@ -0,0 +1,37 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+Synopsis: bit32.bnot (x)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local bnot
+if test_lib.version() == "LuaJIT" then
+    local bitop = require("bit")
+    bnot = bitop.bnot
+else
+    bnot = test_lib.bitwise_op("~")
+end
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = test_lib.random_number(fdp)
+    bnot(x)
+
+    -- For any integer x, the following identity holds [1]:
+    -- 1. https://www.lua.org/manual/5.2/manual.html
+    -- assert(bnot(x) == (-1 - x) % 2^32)
+
+    -- FIXME
+    -- assert(bnot(bnot(x)) == x, "~(~x) ~= x")
+end
+
+local args = {
+    max_len = 4096,
+    max_total_time = 10,
+    artifact_prefix = "bitop_bnot_",
+}
+luzer.Fuzz(TestOneInput, nil, args)

tests/lapi/bitop_bor_test.lua

@@ -0,0 +1,48 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+
+ARM64: Should not fuse sign-extension into logical operands,
+can fuse rotations though,
+https://github.com/LuaJIT/LuaJIT/issues/1076
+
+Wrong code generation for constants in bitwise operations,
+https://github.com/lua/lua/commit/c764ca71a639f5585b5f466bea25dc42b855a4b0
+
+Synopsis: bit32.bor (···)
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+local bor
+if test_lib.version() == "LuaJIT" then
+    local bitop = require("bit")
+    bor = bitop.bor
+else
+    bor = test_lib.bitwise_op("|")
+end
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = test_lib.random_number(fdp)
+    local y = test_lib.random_number(fdp)
+    local z = test_lib.random_number(fdp)
+    bor(x, y)
+
+    assert(bor(x, y) == bor(y, x), "x | y ~= y | x")
+    assert(bor(x, bor(y, z)) == bor(bor(x, y), z),
+           "x | (y | z) ~= (x | y) | z")
+
+    -- FIXME
+    -- assert(bor(x, 0) == x, "x | 0 ~= x")
+    -- assert(bor(x, 0xffff) == 0xffff, "x | 0xFFFF ~= 0xFFFF")
+    -- assert(bor(x, x) == x, "x | x ~= x")
+end
+
+local args = {
+    max_len = 4096,
+    max_total_time = 10,
+    artifact_prefix = "bitop_bor_",
+}
+luzer.Fuzz(TestOneInput, nil, args)

tests/lapi/bitop_bswap_test.lua

@@ -0,0 +1,28 @@
+--[[
+SPDX-License-Identifier: ISC
+Copyright (c) 2023-2025, Sergey Bronnikov.
+]]
+
+local luzer = require("luzer")
+local test_lib = require("lib")
+
+if test_lib.version() ~= "LuaJIT" then
+    os.exit(0)
+end
+
+local bitop = require("bit")
+local bswap = bitop.bswap
+
+local function TestOneInput(buf)
+    local fdp = luzer.FuzzedDataProvider(buf)
+    local x = test_lib.random_number(fdp)
+    local y = test_lib.random_number(fdp)
+    bswap(x, y)
+end
+
+local args = {
+    max_len = 4096,
+    max_total_time = 10,
+    artifact_prefix = "bitop_bswap_",
+}
+luzer.Fuzz(TestOneInput, nil, args)