diff --git a/BUILD b/BUILD
new file mode 100644
index 0000000000..458463e089
--- /dev/null
+++ b/BUILD
@@ -0,0 +1,537 @@
+load(
+    ":build_defs.bzl",
+    "lua_cclibrary",
+    "lua_library",
+    "lua_binary",
+    "lua_test",
+    "generated_file_staleness_test",
+    "make_shell_script",
+    "upb_amalgamation",
+    "upb_proto_library",
+)
+
+# C/C++ rules ##################################################################
+
+cc_library(
+    name = "upb",
+    srcs = [
+        "google/protobuf/descriptor.upb.c",
+        "upb/decode.c",
+        "upb/def.c",
+        "upb/encode.c",
+        "upb/handlers.c",
+        "upb/handlers-inl.h",
+        "upb/msg.c",
+        "upb/msgfactory.c",
+        "upb/port_def.inc",
+        "upb/port_undef.inc",
+        "upb/refcounted.c",
+        "upb/sink.c",
+        "upb/structdefs.int.h",
+        "upb/structs.int.h",
+        "upb/table.c",
+        "upb/table.int.h",
+        "upb/upb.c",
+    ],
+    hdrs = [
+        "google/protobuf/descriptor.upb.h",
+        "upb/decode.h",
+        "upb/def.h",
+        "upb/encode.h",
+        "upb/handlers.h",
+        "upb/msg.h",
+        "upb/msgfactory.h",
+        "upb/refcounted.h",
+        "upb/sink.h",
+        "upb/upb.h",
+    ],
+    copts = [
+        "-std=c89",
+        "-pedantic",
+        "-Wno-long-long",
+    ],
+)
+
+cc_library(
+    name = "upb_descriptor",
+    srcs = [
+        "upb/descriptor/descriptor.upbdefs.c",
+        "upb/descriptor/reader.c",
+    ],
+    hdrs = [
+        "upb/descriptor/descriptor.upbdefs.h",
+        "upb/descriptor/reader.h",
+    ],
+    copts = [
+        "-std=c89",
+        "-pedantic",
+        "-Wno-long-long",
+    ],
+    deps = [":upb"],
+)
+
+cc_library(
+    name = "upb_pb",
+    srcs = [
+        "upb/pb/compile_decoder.c",
+        "upb/pb/decoder.c",
+        "upb/pb/decoder.int.h",
+        "upb/pb/encoder.c",
+        "upb/pb/glue.c",
+        "upb/pb/textprinter.c",
+        "upb/pb/varint.c",
+        "upb/pb/varint.int.h",
+    ],
+    hdrs = [
+        "upb/pb/decoder.h",
+        "upb/pb/encoder.h",
+        "upb/pb/glue.h",
+        "upb/pb/textprinter.h",
+    ],
+    copts = [
+        "-std=c89",
+        "-pedantic",
+        "-Wno-long-long",
+    ],
+    deps = [
+        ":upb",
+        ":upb_descriptor",
+    ],
+)
+
+cc_library(
+    name = "upb_json",
+    srcs = [
+        "upb/json/parser.c",
+        "upb/json/printer.c",
+    ],
+    hdrs = [
+        "upb/json/parser.h",
+        "upb/json/printer.h",
+    ],
+    copts = [
+        "-std=c89",
+        "-pedantic",
+        "-Wno-long-long",
+    ],
+    deps = [":upb"],
+)
+
+cc_library(
+    name = "upb_cc_bindings",
+    hdrs = [
+        "upb/bindings/stdc++/string.h",
+    ],
+    deps = [":upb"],
+)
+
+# Amalgamation #################################################################
+
+py_binary(
+    name = "amalgamate",
+    srcs = ["tools/amalgamate.py"],
+)
+
+upb_amalgamation(
+    name = "gen_amalgamation",
+    outs = [
+        "upb.c",
+        "upb.h",
+    ],
+    amalgamator = ":amalgamate",
+    libs = [
+        ":upb",
+        ":upb_descriptor",
+        ":upb_pb",
+        ":upb_json",
+    ],
+)
+
+cc_library(
+    name = "amalgamation",
+    srcs = ["upb.c"],
+    hdrs = ["upb.h"],
+)
+
+# C/C++ tests ##################################################################
+
+cc_library(
+    name = "upb_test",
+    testonly = 1,
+    srcs = [
+        "tests/testmain.cc",
+    ],
+    hdrs = [
+        "tests/test_util.h",
+        "tests/upb_test.h",
+    ],
+)
+
+cc_test(
+    name = "test_varint",
+    srcs = ["tests/pb/test_varint.c"],
+    deps = [
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_def",
+    srcs = ["tests/test_def.c"],
+    deps = [
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_handlers",
+    srcs = ["tests/test_handlers.c"],
+    deps = [
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_decoder",
+    srcs = ["tests/pb/test_decoder.cc"],
+    deps = [
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_encoder",
+    srcs = ["tests/pb/test_encoder.cc"],
+    data = ["upb/descriptor/descriptor.pb"],
+    deps = [
+        ":upb_cc_bindings",
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_cpp",
+    srcs = ["tests/test_cpp.cc"],
+    deps = [
+        ":upb",
+        ":upb_descriptor",
+        ":upb_pb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_table",
+    srcs = ["tests/test_table.cc"],
+    deps = [
+        ":upb",
+        ":upb_test",
+    ],
+)
+
+cc_test(
+    name = "test_json",
+    srcs = [
+        "tests/json/test.upbdefs.c",
+        "tests/json/test.upbdefs.h",
+        "tests/json/test_json.cc",
+    ],
+    deps = [
+        ":upb_json",
+        ":upb_test",
+    ],
+)
+
+upb_proto_library(
+    name = "conformance_proto_upb",
+    upbc = ":upbc",
+    deps = [
+        "@com_google_protobuf//:conformance_proto",
+        "@com_google_protobuf//:test_messages_proto3_proto",
+    ],
+)
+
+cc_binary(
+    name = "conformance_upb",
+    srcs = [
+        "tests/conformance_upb.c",
+    ],
+    deps = [
+        ":conformance_proto_upb",
+        ":upb",
+    ],
+)
+
+make_shell_script(
+    name = "gen_test_conformance_upb",
+    out = "test_conformance_upb.sh",
+    contents = "$(rlocation com_google_protobuf/conformance_test_runner) $(rlocation upb/conformance_upb)",
+)
+
+sh_test(
+    name = "test_conformance_upb",
+    srcs = ["test_conformance_upb.sh"],
+    data = [
+        "tests/conformance_upb_failures.txt",
+        ":conformance_upb",
+        "@bazel_tools//tools/bash/runfiles",
+        "@com_google_protobuf//:conformance_test_runner",
+    ],
+)
+
+# Lua libraries. ###############################################################
+
+lua_cclibrary(
+    name = "lua/upb_c",
+    srcs = [
+        "upb/bindings/lua/def.c",
+        "upb/bindings/lua/msg.c",
+        "upb/bindings/lua/upb.c",
+    ],
+    hdrs = [
+        "upb/bindings/lua/upb.h",
+    ],
+    deps = [
+        "upb",
+        "upb_pb",
+    ],
+)
+
+lua_library(
+    name = "lua/upb",
+    srcs = ["upb/bindings/lua/upb.lua"],
+    luadeps = ["lua/upb_c"],
+    strip_prefix = "upb/bindings/lua",
+)
+
+lua_cclibrary(
+    name = "lua/upb/table_c",
+    srcs = ["upb/bindings/lua/upb/table.c"],
+    luadeps = ["lua/upb_c"],
+    deps = ["upb"],
+)
+
+lua_library(
+    name = "lua/upb/table",
+    srcs = ["upb/bindings/lua/upb/table.lua"],
+    luadeps = [
+        "lua/upb",
+        "lua/upb/table_c",
+    ],
+    strip_prefix = "upb/bindings/lua",
+)
+
+lua_cclibrary(
+    name = "lua/upb/pb_c",
+    srcs = ["upb/bindings/lua/upb/pb.c"],
+    luadeps = ["lua/upb_c"],
+    deps = ["upb_pb"],
+)
+
+lua_library(
+    name = "lua/upb/pb",
+    srcs = ["upb/bindings/lua/upb/pb.lua"],
+    luadeps = [
+        "lua/upb",
+        "lua/upb/pb_c",
+    ],
+    strip_prefix = "upb/bindings/lua",
+)
+
+lua_library(
+    name = "lua/upbc_lib",
+    srcs = [
+        "tools/dump_cinit.lua",
+        "tools/make_c_api.lua",
+    ],
+    luadeps = [
+        "lua/upb",
+        "lua/upb/table",
+    ],
+    strip_prefix = "tools",
+)
+
+# Lua tests. ###################################################################
+
+lua_test(
+    name = "lua/test_upb",
+    luadeps = ["lua/upb"],
+    luamain = "tests/bindings/lua/test_upb.lua",
+)
+
+lua_test(
+    name = "lua/test_upb_pb",
+    luadeps = ["lua/upb/pb"],
+    luamain = "tests/bindings/lua/test_upb.pb.lua",
+)
+
+# upb compiler #################################################################
+
+lua_binary(
+    name = "upbc",
+    luadeps = [
+        "lua/upbc_lib",
+    ],
+    luamain = "tools/upbc.lua",
+)
+
+# Test the CMake build #########################################################
+
+make_shell_script(
+    name = "gen_run_cmake_build",
+    out = "run_cmake_build.sh",
+    contents = "mkdir build && cd build && cmake .. && make -j8"
+)
+
+sh_test(
+    name = "cmake_build",
+    srcs = ["run_cmake_build.sh"],
+    data = glob([
+        "CMakeLists.txt",
+        "google/**/*",
+        "upb/**/*",
+        "tests/**/*",
+    ]) + [
+        "@bazel_tools//tools/bash/runfiles",
+    ],
+)
+
+# Generated files ##############################################################
+
+exports_files(["tools/staleness_test.py"])
+
+py_library(
+    name = "staleness_test_lib",
+    testonly = 1,
+    srcs = ["tools/staleness_test_lib.py"],
+)
+
+genrule(
+    name = "make_dynasm_decoder",
+    srcs = [
+        "third_party/dynasm/dynasm.lua",
+        "third_party/dynasm/dasm_x64.lua",
+        "third_party/dynasm/dasm_x86.lua",
+        "upb/pb/compile_decoder_x64.dasc",
+    ],
+    outs = ["generated/upb/pb/compile_decoder_x64.h"],
+    cmd = "LUA_PATH=third_party/dynasm/?.lua $(location @lua//:lua) third_party/dynasm/dynasm.lua -c upb/pb/compile_decoder_x64.dasc > $@",
+    tools = ["@lua"],
+)
+
+proto_library(
+    name = "upb_descriptor_proto",
+    srcs = [
+        "upb/descriptor/descriptor.proto",
+    ],
+)
+
+py_binary(
+    name = "make_cmakelists",
+    srcs = ["tools/make_cmakelists.py"],
+)
+
+genrule(
+    name = "gen_cmakelists",
+    outs = ["generated/CMakeLists.txt"],
+    srcs = ["BUILD", "WORKSPACE"],
+    tools = [":make_cmakelists"],
+    cmd = "$(location :make_cmakelists) $@"
+)
+
+genrule(
+    name = "copy_upb_descriptor_pb",
+    srcs = [":upb_descriptor_proto"],
+    outs = ["generated/upb/descriptor/descriptor.pb"],
+    cmd = "cp $< $@",
+)
+
+genrule(
+    name = "generate_old_upbdefs",
+    srcs = ["generated/upb/descriptor/descriptor.pb"],
+    outs = [
+        "generated/upb/descriptor/descriptor.upbdefs.h",
+        "generated/upb/descriptor/descriptor.upbdefs.c",
+    ],
+    cmd = "UPBC=$$PWD/$(location :upbc); INFILE=$$PWD/$<; cd $(GENDIR)/generated && $$UPBC --generate-upbdefs $$INFILE",
+    tools = [":upbc"],
+)
+
+proto_library(
+    name = "google_descriptor_proto",
+    srcs = [
+        "google/protobuf/descriptor.proto",
+    ],
+)
+
+genrule(
+    name = "copy_google_descriptor_pb",
+    srcs = [":google_descriptor_proto"],
+    outs = ["generated/google/protobuf/descriptor.pb"],
+    cmd = "cp $< $@",
+)
+
+genrule(
+    name = "generate_descriptor_c",
+    srcs = ["generated/google/protobuf/descriptor.pb"],
+    outs = [
+        "generated/google/protobuf/descriptor.upb.h",
+        "generated/google/protobuf/descriptor.upb.c",
+    ],
+    cmd = "UPBC=$$PWD/$(location :upbc); INFILE=$$PWD/$<; cd $(GENDIR)/generated && $$UPBC $$INFILE",
+    tools = [":upbc"],
+)
+
+proto_library(
+    name = "json_test_proto",
+    srcs = ["tests/json/test.proto"],
+)
+
+genrule(
+    name = "copy_json_test_proto",
+    srcs = [":json_test_proto"],
+    outs = ["generated/tests/json/test.proto.pb"],
+    cmd = "cp $< $@",
+)
+
+genrule(
+    name = "generated_json_test_proto_upbdefs",
+    srcs = ["generated/tests/json/test.proto.pb"],
+    outs = [
+        "generated/tests/json/test.upbdefs.h",
+        "generated/tests/json/test.upbdefs.c",
+    ],
+    cmd = "UPBC=$$PWD/$(location :upbc); INFILE=$$PWD/$<; cd $(GENDIR)/generated && $$UPBC --generate-upbdefs $$INFILE",
+    tools = [":upbc"],
+)
+
+genrule(
+    name = "generate_json_ragel",
+    srcs = ["upb/json/parser.rl"],
+    outs = ["generated/upb/json/parser.c"],
+    cmd = "$(location @ragel//:ragel) -C -o upb/json/parser.c $< && mv upb/json/parser.c $@",
+    tools = ["@ragel"],
+)
+
+generated_file_staleness_test(
+    name = "test_generated_files",
+    outs = [
+        "CMakeLists.txt",
+        "google/protobuf/descriptor.upb.c",
+        "google/protobuf/descriptor.upb.h",
+        "tests/json/test.proto.pb",
+        "tests/json/test.upbdefs.c",
+        "tests/json/test.upbdefs.h",
+        "upb/descriptor/descriptor.pb",
+        "upb/descriptor/descriptor.upbdefs.c",
+        "upb/descriptor/descriptor.upbdefs.h",
+        "upb/json/parser.c",
+        "upb/pb/compile_decoder_x64.h",
+    ],
+    generated_pattern = "generated/%s",
+)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ba572fa2ea..5c6d5fa032 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,3 +1,4 @@
+# This file was generated from BUILD using tools/make_cmakelists.py.
 
 cmake_minimum_required(VERSION 3.1)
 
@@ -9,16 +10,14 @@ endif()
 
 cmake_minimum_required (VERSION 3.0)
 cmake_policy(SET CMP0048 NEW)
-project (upb)
+
+project(upb)
+
 
 # Prevent CMake from setting -rdynamic on Linux (!!).
 SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 SET(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
 
-# Options we define for users.
-option(UPB_ENABLE_ASAN "Enable address sanitizer." OFF)
-option(UPB_ENABLE_UBSAN "Enable undefined behavior sanitizer." OFF)
-
 # Set default build type.
 if(NOT CMAKE_BUILD_TYPE)
   message(STATUS "Setting build type to 'RelWithDebInfo' as none was specified.")
@@ -51,8 +50,6 @@ endif()
 
 include_directories(.)
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
-set(CMAKE_CXX_FLAGS "-std=c++11 -W -Wall -Wno-sign-compare")
-set(CMAKE_C_FLAGS "-std=c89 -W -Wall -Wno-sign-compare")
 
 if(APPLE)
   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -undefined dynamic_lookup -flat_namespace")
@@ -60,250 +57,132 @@ elseif(UNIX)
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--build-id")
 endif()
 
-FIND_PACKAGE(Lua)
-if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/Makefile.am")
-  set(PROTOBUF_FOUND TRUE)
-endif()
-find_program(RAGEL NAMES ragel)
-
-if(LUA_FOUND)
-  include_directories(${LUA_INCLUDE_DIR})
-
-  add_library(upb_c SHARED
-    upb/bindings/lua/upb.c
-    upb/bindings/lua/def.c
-    upb/bindings/lua/msg.c
-  )
-  target_link_libraries(upb_c LINK_PRIVATE
-    upbpb_pic
-    upbdef_pic
-    upbhandlers_pic upb_pic )
-
-  add_library(table_c SHARED
-    upb/bindings/lua/upb/table.c
-  )
-  target_link_libraries(table_c LINK_PRIVATE upb_c upb_pic)
-
-  add_library(pb_c SHARED
-    upb/bindings/lua/upb/pb.c
-  )
-  target_link_libraries(pb_c LINK_PRIVATE upb_c upbpb_pic)
-
-  set_target_properties(upb_c
-    PROPERTIES
-    LIBRARY_OUTPUT_DIRECTORY "lua"
-    PREFIX ""
-    SUFFIX ".so")
-  set_target_properties(table_c pb_c
-    PROPERTIES
-    LIBRARY_OUTPUT_DIRECTORY "lua/upb"
-    PREFIX ""
-    SUFFIX ".so")
-
-  add_custom_command(
-        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/tools/upbc
-        DEPENDS ${CMAKE_SOURCE_DIR}/tools/upbc
-                ${CMAKE_SOURCE_DIR}/tools/upbc.lua
-                ${CMAKE_SOURCE_DIR}/tools/dump_cinit.lua
-                ${CMAKE_SOURCE_DIR}/tools/make_c_api.lua
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb.lua
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/table.lua
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/pb.lua
-                upb_c
-                table_c
-                pb_c
-        COMMAND ${CMAKE_COMMAND} -E copy
-                ${CMAKE_SOURCE_DIR}/tools/upbc
-                ${CMAKE_SOURCE_DIR}/tools/upbc.lua
-                ${CMAKE_SOURCE_DIR}/tools/dump_cinit.lua
-                ${CMAKE_SOURCE_DIR}/tools/make_c_api.lua
-                ${CMAKE_CURRENT_BINARY_DIR}/tools)
-  add_custom_command(
-        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/lua/upb.lua
-        DEPENDS ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb.lua
-        COMMAND ${CMAKE_COMMAND} -E copy
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb.lua
-                ${CMAKE_CURRENT_BINARY_DIR}/lua)
-  add_custom_command(
-        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/lua/upb/table.lua
-               ${CMAKE_CURRENT_BINARY_DIR}/lua/upb/pb.lua
-        DEPENDS ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/table.lua
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/pb.lua
-        COMMAND ${CMAKE_COMMAND} -E copy
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/table.lua
-                ${CMAKE_SOURCE_DIR}/upb/bindings/lua/upb/pb.lua
-                ${CMAKE_CURRENT_BINARY_DIR}/lua/upb)
-
-  add_custom_command(
-    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/upb/pb/compile_decoder_x64.h
-    DEPENDS upb/pb/compile_decoder_x64.dasc
-    COMMAND
-        cd ${CMAKE_CURRENT_SOURCE_DIR} &&
-        lua third_party/dynasm/dynasm.lua
-        -c upb/pb/compile_decoder_x64.dasc
-        > ${CMAKE_CURRENT_BINARY_DIR}/upb/pb/compile_decoder_x64.h
-  )
-
-  add_custom_target(
-    upbc ALL
-    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/tools/make_c_api.lua
-            ${CMAKE_CURRENT_SOURCE_DIR}/tools/upbc.lua
-            ${CMAKE_CURRENT_BINARY_DIR}/tools/upbc
-            ${CMAKE_CURRENT_BINARY_DIR}/lua/upb.lua
-            ${CMAKE_CURRENT_BINARY_DIR}/lua/upb/pb.lua
-  )
-
-  add_custom_target(
-    genfiles2 ALL
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/upb/pb/compile_decoder_x64.h
-  )
-
-  add_test(
-    NAME testlua
-    COMMAND lua ${CMAKE_SOURCE_DIR}/tests/bindings/lua/test_upb.lua
-                ${CMAKE_SOURCE_DIR}/tests/bindings/lua/test_upb.pb.lua
-  )
-  set_property(TEST testlua PROPERTY ENVIRONMENT
-      LUA_PATH=${CMAKE_SOURCE_DIR}/third_party/lunit/?.lua$<SEMICOLON>${CMAKE_SOURCE_DIR}/upb/bindings/lua/?.lua
-      LUA_CPATH=${CMAKE_BINARY_DIR}/upb/bindings/lua/?.so
-  )
-  set_tests_properties(testlua
-    PROPERTIES
-    DEPENDS "upb_c;pb_c"
-  )
-  enable_testing()
-endif()
-
-if(LUA_FOUND AND PROTOBUF_FOUND)
-  set(protobuf_BUILD_TESTS OFF CACHE BOOL "enable tests for proto2" FORCE)
-  set(protobuf_BUILD_SHARED_LIBS OFF CACHE BOOL "enable shared libs for proto2" FORCE)
-  set(protobuf_BUILD_CONFORMANCE ON CACHE BOOL "Build conformance tests" FORCE)
-  add_subdirectory(third_party/protobuf/cmake)
-
-  add_custom_command(
-    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/conformance.upb.h
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/test_messages_proto3.upb.h
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/test_messages_proto3.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/any.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/duration.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/field_mask.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/struct.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/timestamp.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/wrappers.upb.c
-           ${CMAKE_CURRENT_BINARY_DIR}/conformance.upb.c
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/tools/upbc
-            ${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/conformance/conformance.proto
-    COMMAND protoc --include_imports
-        ${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/conformance/conformance.proto
-        ${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/src/google/protobuf/test_messages_proto3.proto
-        -I${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/conformance
-        -I${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf/src
-        -o${CMAKE_CURRENT_BINARY_DIR}/conformance.pb &&
-        tools/upbc ${CMAKE_CURRENT_BINARY_DIR}/conformance.pb
-  )
-
-  add_custom_command(
-    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/descriptor.upb.h
-           ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/descriptor.upb.c
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/tools/upbc
-            ${CMAKE_CURRENT_SOURCE_DIR}/google/protobuf/descriptor.proto
-    COMMAND protoc
-        ${CMAKE_CURRENT_SOURCE_DIR}/google/protobuf/descriptor.proto
-        -I${CMAKE_CURRENT_SOURCE_DIR}
-        -o${CMAKE_CURRENT_BINARY_DIR}/descriptor.pb &&
-        tools/upbc ${CMAKE_CURRENT_BINARY_DIR}/descriptor.pb
-  )
-
-  add_custom_target(
-    genfiles ALL
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/conformance.upb.h
-            ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/descriptor.upb.h
-  )
-
-  add_executable(conformance_upb
-    tests/conformance_upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/conformance.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/test_messages_proto3.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/any.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/duration.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/field_mask.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/struct.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/timestamp.upb.c
-    ${CMAKE_CURRENT_BINARY_DIR}/google/protobuf/wrappers.upb.c
-  )
-  target_link_libraries(conformance_upb LINK_PRIVATE
-    upb
-  )
-
-  add_custom_target(
-    conformance
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/conformance_upb
-            ${CMAKE_CURRENT_BINARY_DIR}/third_party/protobuf/cmake/conformance_test_runner
-    COMMAND ${CMAKE_CURRENT_BINARY_DIR}/third_party/protobuf/cmake/conformance_test_runner ${CMAKE_CURRENT_BINARY_DIR}/conformance_upb
-  )
-
-endif()
-
-if (RAGEL)
-  add_custom_command(
-    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/upb/json/parser.c
-    DEPENDS upb/json/parser.rl
-    COMMAND cd ${CMAKE_CURRENT_SOURCE_DIR} && RAGEL -C -o ${CMAKE_CURRENT_BINARY_DIR}/upb/json/parser.c upb/json/parser.rl
-  )
-endif()
-
-configure_file(tools/copy_genfiles.sh.in tools/copy_genfiles.sh)
-
-set(UPB_SRCS
-    upb/decode.c
-    upb/encode.c
-    upb/msg.c
-    upb/table.c
-    upb/upb.c
-)
-
-set (UPBDEF_SRCS
-    upb/descriptor/descriptor.upbdefs.c
-    upb/descriptor/reader.c
-    upb/def.c
-    upb/msgfactory.c
-    upb/refcounted.c
-)
-
-set(UPBHANDLERS_SRCS
-    upb/sink.c
-    upb/handlers.c
-)
-
-set(UPBPB_SRCS
+enable_testing()
+
+add_library(upb
+  google/protobuf/descriptor.upb.c
+  upb/decode.c
+  upb/def.c
+  upb/encode.c
+  upb/handlers.c
+  upb/handlers-inl.h
+  upb/msg.c
+  upb/msgfactory.c
+  upb/port_def.inc
+  upb/port_undef.inc
+  upb/refcounted.c
+  upb/sink.c
+  upb/structdefs.int.h
+  upb/structs.int.h
+  upb/table.c
+  upb/table.int.h
+  upb/upb.c
+  google/protobuf/descriptor.upb.h
+  upb/decode.h
+  upb/def.h
+  upb/encode.h
+  upb/handlers.h
+  upb/msg.h
+  upb/msgfactory.h
+  upb/refcounted.h
+  upb/sink.h
+  upb/upb.h)
+add_library(upb_descriptor
+  upb/descriptor/descriptor.upbdefs.c
+  upb/descriptor/reader.c
+  upb/descriptor/descriptor.upbdefs.h
+  upb/descriptor/reader.h)
+target_link_libraries(upb_descriptor
+  upb)
+add_library(upb_pb
   upb/pb/compile_decoder.c
   upb/pb/decoder.c
+  upb/pb/decoder.int.h
   upb/pb/encoder.c
   upb/pb/glue.c
   upb/pb/textprinter.c
   upb/pb/varint.c
-)
-
-set(UPBJSON_SRCS
+  upb/pb/varint.int.h
+  upb/pb/decoder.h
+  upb/pb/encoder.h
+  upb/pb/glue.h
+  upb/pb/textprinter.h)
+target_link_libraries(upb_pb
+  upb
+  upb_descriptor)
+add_library(upb_json
   upb/json/parser.c
   upb/json/printer.c
-)
-
-add_library(upb ${UPB_SRCS})
-add_library(upbdef ${UPBDEF_SRCS})
-add_library(upbhandlers ${UPBHANDLERS_SRCS})
-add_library(upbpb ${UPBPB_SRCS})
-add_library(upbjson ${UPBJSON_SRCS})
-
-add_library(upb_pic ${UPB_SRCS})
-add_library(upbdef_pic ${UPBDEF_SRCS})
-add_library(upbhandlers_pic ${UPBHANDLERS_SRCS})
-add_library(upbpb_pic ${UPBPB_SRCS})
-add_library(upbjson_pic ${UPBJSON_SRCS})
+  upb/json/parser.h
+  upb/json/printer.h)
+target_link_libraries(upb_json
+  upb)
+add_library(upb_cc_bindings
+  upb/bindings/stdc++/string.h)
+target_link_libraries(upb_cc_bindings
+  upb)
+set_target_properties(upb_cc_bindings PROPERTIES LINKER_LANGUAGE CXX)
+add_library(upb_test
+  tests/testmain.cc
+  tests/test_util.h
+  tests/upb_test.h)
+add_executable(test_varint
+  tests/pb/test_varint.c)
+add_test(NAME test_varint COMMAND test_varint)
+target_link_libraries(test_varint
+  upb_pb
+  upb_test)
+add_executable(test_def
+  tests/test_def.c)
+add_test(NAME test_def COMMAND test_def)
+target_link_libraries(test_def
+  upb_pb
+  upb_test)
+add_executable(test_handlers
+  tests/test_handlers.c)
+add_test(NAME test_handlers COMMAND test_handlers)
+target_link_libraries(test_handlers
+  upb_pb
+  upb_test)
+add_executable(test_decoder
+  tests/pb/test_decoder.cc)
+add_test(NAME test_decoder COMMAND test_decoder)
+target_link_libraries(test_decoder
+  upb_pb
+  upb_test)
+add_executable(test_encoder
+  tests/pb/test_encoder.cc)
+add_test(NAME test_encoder COMMAND test_encoder)
+add_custom_command(
+    TARGET test_encoder POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy
+            ${CMAKE_SOURCE_DIR}/upb/descriptor/descriptor.pb
+            ${CMAKE_CURRENT_BINARY_DIR}/upb/descriptor/descriptor.pb)
+target_link_libraries(test_encoder
+  upb_cc_bindings
+  upb_pb
+  upb_test)
+add_executable(test_cpp
+  tests/test_cpp.cc)
+add_test(NAME test_cpp COMMAND test_cpp)
+target_link_libraries(test_cpp
+  upb
+  upb_descriptor
+  upb_pb
+  upb_test)
+add_executable(test_table
+  tests/test_table.cc)
+add_test(NAME test_table COMMAND test_table)
+target_link_libraries(test_table
+  upb
+  upb_test)
+add_executable(test_json
+  tests/json/test.upbdefs.c
+  tests/json/test.upbdefs.h
+  tests/json/test_json.cc)
+add_test(NAME test_json COMMAND test_json)
+target_link_libraries(test_json
+  upb_json
+  upb_test)
 
-set_property(TARGET upb_pic PROPERTY POSITION_INDEPENDENT_CODE ON)
-set_property(TARGET upbdef_pic PROPERTY POSITION_INDEPENDENT_CODE ON)
-set_property(TARGET upbhandlers_pic PROPERTY POSITION_INDEPENDENT_CODE ON)
-set_property(TARGET upbpb_pic PROPERTY POSITION_INDEPENDENT_CODE ON)
-set_property(TARGET upbjson_pic PROPERTY POSITION_INDEPENDENT_CODE ON)
 
diff --git a/WORKSPACE b/WORKSPACE
new file mode 100644
index 0000000000..b4d19c50a8
--- /dev/null
+++ b/WORKSPACE
@@ -0,0 +1,40 @@
+
+workspace(name = "upb")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+
+http_archive(
+    name = "lua",
+    build_file = "//:lua.BUILD",
+    sha256 = "b9e2e4aad6789b3b63a056d442f7b39f0ecfca3ae0f1fc0ae4e9614401b69f4b",
+    strip_prefix = "lua-5.2.4",
+    urls = [
+        "https://mirror.bazel.build/www.lua.org/ftp/lua-5.2.4.tar.gz",
+        "https://www.lua.org/ftp/lua-5.2.4.tar.gz",
+    ],
+)
+
+git_repository(
+    name = "com_google_protobuf",
+    commit = "25feb59620627b673df76813dfd66e3f565765e7",
+    #sha256 = "d7a221b3d4fb4f05b7473795ccea9e05dab3b8721f6286a95fffbffc2d926f8b",
+    remote = "https://github.com/haberman/protobuf.git",
+    #tag = "conformance-build-tag",
+)
+
+http_archive(
+    name = "ragel",
+    sha256 = "5f156edb65d20b856d638dd9ee2dfb43285914d9aa2b6ec779dac0270cd56c3f",
+    build_file = "//:ragel.BUILD",
+    strip_prefix = "ragel-6.10",
+    urls = ["http://www.colm.net/files/ragel/ragel-6.10.tar.gz"],
+)
+
+# Used by protobuf.
+http_archive(
+    name = "bazel_skylib",
+    sha256 = "bbccf674aa441c266df9894182d80de104cabd19be98be002f6d478aaa31574d",
+    strip_prefix = "bazel-skylib-2169ae1c374aab4a09aa90e65efe1a3aad4e279b",
+    urls = ["https://github.com/bazelbuild/bazel-skylib/archive/2169ae1c374aab4a09aa90e65efe1a3aad4e279b.tar.gz"],
+)
diff --git a/build_defs.bzl b/build_defs.bzl
new file mode 100644
index 0000000000..0e58bbbca4
--- /dev/null
+++ b/build_defs.bzl
@@ -0,0 +1,273 @@
+
+_shell_find_runfiles = """
+  # --- begin runfiles.bash initialization ---
+  # Copy-pasted from Bazel's Bash runfiles library (tools/bash/runfiles/runfiles.bash).
+  set -euo pipefail
+  if [[ ! -d "${RUNFILES_DIR:-/dev/null}" && ! -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+    if [[ -f "$0.runfiles_manifest" ]]; then
+      export RUNFILES_MANIFEST_FILE="$0.runfiles_manifest"
+    elif [[ -f "$0.runfiles/MANIFEST" ]]; then
+      export RUNFILES_MANIFEST_FILE="$0.runfiles/MANIFEST"
+    elif [[ -f "$0.runfiles/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+      export RUNFILES_DIR="$0.runfiles"
+    fi
+  fi
+  if [[ -f "${RUNFILES_DIR:-/dev/null}/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+    source "${RUNFILES_DIR}/bazel_tools/tools/bash/runfiles/runfiles.bash"
+  elif [[ -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+    source "$(grep -m1 "^bazel_tools/tools/bash/runfiles/runfiles.bash " \
+              "$RUNFILES_MANIFEST_FILE" | cut -d ' ' -f 2-)"
+  else
+    echo >&2 "ERROR: cannot find @bazel_tools//tools/bash/runfiles:runfiles.bash"
+    exit 1
+  fi
+  # --- end runfiles.bash initialization ---
+"""
+
+def _librule(name):
+    return name + "_lib"
+
+def lua_cclibrary(name, srcs, hdrs = [], deps = [], luadeps = []):
+    lib_rule = name + "_lib"
+    so_rule = "lib" + name + ".so"
+    so_file = _remove_prefix(name, "lua/") + ".so"
+
+    native.cc_library(
+        name = _librule(name),
+        hdrs = hdrs,
+        srcs = srcs,
+        deps = deps + [_librule(dep) for dep in luadeps] + ["@lua//:liblua_headers"],
+    )
+
+    native.cc_binary(
+        name = so_rule,
+        linkshared = True,
+        deps = [_librule(name)],
+    )
+
+    native.genrule(
+        name = name + "_copy",
+        srcs = [":" + so_rule],
+        outs = [so_file],
+        cmd = "cp $< $@",
+    )
+
+    native.filegroup(
+        name = name,
+        data = [so_file],
+    )
+
+def _remove_prefix(str, prefix):
+    if not str.startswith(prefix):
+        fail("%s doesn't start with %s" % (str, prefix))
+    return str[len(prefix):]
+
+def _remove_suffix(str, suffix):
+    if not str.endswith(suffix):
+        fail("%s doesn't end with %s" % (str, suffix))
+    return str[:-len(suffix)]
+
+def lua_library(name, srcs, strip_prefix, luadeps = []):
+    outs = [_remove_prefix(src, strip_prefix + "/") for src in srcs]
+    native.genrule(
+        name = name + "_copy",
+        srcs = srcs,
+        outs = outs,
+        cmd = "cp $(SRCS) $(@D)",
+    )
+
+    native.filegroup(
+        name = name,
+        data = outs + luadeps,
+    )
+
+def make_shell_script(name, contents, out):
+    script_contents = (_shell_find_runfiles + contents).replace("$", "$$")
+    native.genrule(
+        name = "gen_" + name,
+        outs = [out],
+        cmd = "(cat <<'HEREDOC'\n%s\nHEREDOC\n) > $@" % script_contents,
+    )
+
+def _lua_binary_or_test(name, luamain, luadeps, rule):
+    script = name + ".sh"
+
+    make_shell_script(
+        name = "gen_" + name,
+        out = script,
+        contents = """
+BASE=$(dirname $(rlocation upb/upb_c.so))
+export LUA_CPATH="$BASE/?.so"
+export LUA_PATH="$BASE/?.lua"
+$(rlocation lua/lua) $(rlocation upb/tools/upbc.lua) "$@"
+"""
+    )
+
+    rule(
+        name = name,
+        srcs = [script],
+        data = ["@lua//:lua", "@bazel_tools//tools/bash/runfiles", luamain] + luadeps,
+    )
+
+def lua_binary(name, luamain, luadeps=[]):
+    _lua_binary_or_test(name, luamain, luadeps, native.sh_binary)
+
+def lua_test(name, luamain, luadeps=[]):
+    _lua_binary_or_test(name, luamain, luadeps, native.sh_test)
+
+def generated_file_staleness_test(name, outs, generated_pattern):
+    """Tests that checked-in file(s) match the contents of generated file(s).
+
+    The resulting test will verify that all output files exist and have the
+    correct contents.  If the test fails, it can be invoked with --fix to
+    bring the checked-in files up to date.
+
+    Args:
+      name: Name of the rule.
+      outs: the checked-in files that are copied from generated files.
+      generated_pattern: the pattern for transforming each "out" file into a
+        generated file.  For example, if generated_pattern="generated/%s" then
+        a file foo.txt will look for generated file generated/foo.txt.
+    """
+
+    script_name = name + ".py"
+    script_src = "//:tools/staleness_test.py"
+
+    # Filter out non-existing rules so Blaze doesn't error out before we even
+    # run the test.
+    existing_outs = native.glob(include = outs)
+
+    # The file list contains a few extra bits of information at the end.
+    # These get unpacked by the Config class in staleness_test_lib.py.
+    file_list = outs + [generated_pattern, native.package_name() or ".", name]
+
+    native.genrule(
+        name = name + "_makescript",
+        outs = [script_name],
+        srcs = [script_src],
+        testonly = 1,
+        cmd = "cat $(location " + script_src + ") > $@; " +
+              "sed -i 's|INSERT_FILE_LIST_HERE|" + "\\n  ".join(file_list) + "|' $@",
+    )
+
+    native.py_test(
+        name = name,
+        srcs = [script_name],
+        data = existing_outs + [generated_pattern % file for file in outs],
+        deps = [
+            "//:staleness_test_lib",
+        ],
+    )
+
+# upb_amalgamation() rule, with file_list aspect.
+
+SrcList = provider(
+    fields = {
+        'srcs' : 'list of srcs',
+        'hdrs' : 'list of hdrs',
+    }
+)
+
+def _file_list_aspect_impl(target, ctx):
+    srcs = []
+    hdrs = []
+    for src in ctx.rule.attr.srcs:
+        srcs += src.files.to_list()
+    for hdr in ctx.rule.attr.hdrs:
+        hdrs += hdr.files.to_list()
+    return [SrcList(srcs = srcs, hdrs = hdrs)]
+
+_file_list_aspect = aspect(
+    implementation = _file_list_aspect_impl,
+)
+
+def _upb_amalgamation(ctx):
+    srcs = []
+    hdrs = []
+    for lib in ctx.attr.libs:
+        srcs += lib[SrcList].srcs
+        hdrs += lib[SrcList].hdrs
+    ctx.actions.run(
+        inputs = srcs + hdrs,
+        outputs = ctx.outputs.outs,
+        arguments = ["", ctx.bin_dir.path + "/"] + [f.path for f in srcs],
+        progress_message = "Making amalgamation",
+        executable = ctx.executable.amalgamator,
+    )
+
+upb_amalgamation = rule(
+    implementation = _upb_amalgamation,
+    attrs = {
+        "amalgamator": attr.label(
+            executable = True,
+            cfg = "host",
+        ),
+        "libs": attr.label_list(aspects = [_file_list_aspect]),
+        "outs": attr.output_list(),
+    }
+)
+
+# upb_proto_library() rule
+
+def _remove_up(string):
+    if string.startswith("../"):
+        string = string[3:]
+        pos = string.find("/")
+        string = string[pos + 1:]
+
+    return _remove_suffix(string, ".proto")
+
+def _upb_proto_library_srcs_impl(ctx):
+    descriptors = []
+    outs = []
+    for dep in ctx.attr.deps:
+        if hasattr(dep, 'proto'):
+            for desc in dep.proto.transitive_descriptor_sets:
+                descriptors.append(desc)
+            for src in dep.proto.transitive_sources:
+                outs.append(ctx.actions.declare_file(_remove_up(src.short_path) + ".upb.h"))
+                outs.append(ctx.actions.declare_file(_remove_up(src.short_path) + ".upb.c"))
+                outdir = _remove_suffix(outs[-1].path, _remove_up(src.short_path) + ".upb.c")
+
+    concatenated = ctx.actions.declare_file(ctx.label.name + "_concatenated_descriptor.bin")
+    descriptor_paths = [d.path for d in descriptors]
+
+    ctx.actions.run_shell(
+        inputs = descriptors,
+        outputs = [concatenated],
+        progress_message = "Concatenating descriptors",
+        command = "cat %s > %s" % (" ".join(descriptor_paths), concatenated.path),
+    )
+    ctx.actions.run(
+        inputs = [concatenated],
+        outputs = outs,
+        executable = ctx.executable.upbc,
+        arguments = ["--outdir", outdir, concatenated.path],
+        progress_message = "Generating upb protos",
+    )
+
+    return [DefaultInfo(files = depset(outs))]
+
+_upb_proto_library_srcs = rule(
+    implementation = _upb_proto_library_srcs_impl,
+    attrs = {
+        "upbc": attr.label(
+            executable = True,
+            cfg = "host",
+        ),
+        "deps": attr.label_list(),
+    }
+)
+
+def upb_proto_library(name, deps, upbc):
+    srcs_rule = name + "_srcs.cc"
+    _upb_proto_library_srcs(
+        name = srcs_rule,
+        upbc = upbc,
+        deps = deps,
+    )
+    native.cc_library(
+        name = name,
+        srcs = [":" + srcs_rule],
+        deps = [":upb"],
+    )
diff --git a/kokoro/ubuntu/build.sh b/kokoro/ubuntu/build.sh
new file mode 100644
index 0000000000..bbf8841c56
--- /dev/null
+++ b/kokoro/ubuntu/build.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+cd $(dirname $0)/../..
+bazel test :all
diff --git a/kokoro/ubuntu/continuous.cfg b/kokoro/ubuntu/continuous.cfg
new file mode 100644
index 0000000000..fa97583b34
--- /dev/null
+++ b/kokoro/ubuntu/continuous.cfg
@@ -0,0 +1,2 @@
+build_file: "upb/kokoro/ubuntu/build.sh"
+timeout_mins: 15
diff --git a/kokoro/ubuntu/presubmit.cfg b/kokoro/ubuntu/presubmit.cfg
new file mode 100644
index 0000000000..fa97583b34
--- /dev/null
+++ b/kokoro/ubuntu/presubmit.cfg
@@ -0,0 +1,2 @@
+build_file: "upb/kokoro/ubuntu/build.sh"
+timeout_mins: 15
diff --git a/lua.BUILD b/lua.BUILD
new file mode 100644
index 0000000000..7be0b594e5
--- /dev/null
+++ b/lua.BUILD
@@ -0,0 +1,102 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "liblua_headers",
+    defines = ["LUA_USE_LINUX"],
+    hdrs = [
+        "src/lauxlib.h",
+        "src/lua.h",
+        "src/lua.hpp",
+        "src/luaconf.h",
+        "src/lualib.h",
+    ],
+    includes = ["src"],
+)
+
+cc_library(
+    name = "liblua",
+    srcs = [
+        "src/lapi.c",
+        "src/lapi.h",
+        "src/lauxlib.c",
+        "src/lauxlib.h",
+        "src/lbaselib.c",
+        "src/lbitlib.c",
+        "src/lcode.c",
+        "src/lcode.h",
+        "src/lcorolib.c",
+        "src/lctype.c",
+        "src/lctype.h",
+        "src/ldblib.c",
+        "src/ldebug.c",
+        "src/ldebug.h",
+        "src/ldo.c",
+        "src/ldo.h",
+        "src/ldump.c",
+        "src/lfunc.c",
+        "src/lfunc.h",
+        "src/lgc.c",
+        "src/lgc.h",
+        "src/linit.c",
+        "src/liolib.c",
+        "src/llex.c",
+        "src/llex.h",
+        "src/llimits.h",
+        "src/lmathlib.c",
+        "src/lmem.c",
+        "src/lmem.h",
+        "src/loadlib.c",
+        "src/lobject.c",
+        "src/lobject.h",
+        "src/lopcodes.c",
+        "src/lopcodes.h",
+        "src/loslib.c",
+        "src/lparser.c",
+        "src/lparser.h",
+        "src/lstate.c",
+        "src/lstate.h",
+        "src/lstring.c",
+        "src/lstring.h",
+        "src/lstrlib.c",
+        "src/ltable.c",
+        "src/ltable.h",
+        "src/ltablib.c",
+        "src/ltm.c",
+        "src/ltm.h",
+        "src/lundump.c",
+        "src/lundump.h",
+        "src/lvm.c",
+        "src/lvm.h",
+        "src/lzio.c",
+        "src/lzio.h",
+    ],
+    defines = ["LUA_USE_LINUX"],
+    hdrs = [
+        "src/lauxlib.h",
+        "src/lua.h",
+        "src/lua.hpp",
+        "src/luaconf.h",
+        "src/lualib.h",
+    ],
+    includes = ["src"],
+    linkopts = [
+        "-lm",
+        "-ldl",
+    ],
+)
+
+cc_binary(
+    name = "lua",
+    srcs = [
+        "src/lua.c",
+    ],
+    deps = [
+        ":liblua",
+    ],
+    linkopts = [
+        "-lreadline",
+        "-rdynamic",
+    ],
+)
diff --git a/ragel.BUILD b/ragel.BUILD
new file mode 100644
index 0000000000..5485faba0b
--- /dev/null
+++ b/ragel.BUILD
@@ -0,0 +1,193 @@
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+cc_binary(
+    name = "ragel",
+    srcs = [
+        "ragel/rubycodegen.cpp",
+        "ragel/goipgoto.h",
+        "ragel/cdtable.h",
+        "ragel/rubycodegen.h",
+        "ragel/gotable.h",
+        "ragel/gocodegen.cpp",
+        "ragel/rubyfflat.cpp",
+        "ragel/common.cpp",
+        "ragel/gofflat.cpp",
+        "ragel/cdtable.cpp",
+        "ragel/cdsplit.cpp",
+        "ragel/rlparse.cpp",
+        "ragel/csfgoto.cpp",
+        "ragel/javacodegen.cpp",
+        "ragel/gocodegen.h",
+        "ragel/mlgoto.cpp",
+        "ragel/fsmgraph.cpp",
+        "ragel/version.h",
+        "ragel/mlfflat.h",
+        "ragel/fsmgraph.h",
+        "ragel/fsmbase.cpp",
+        "ragel/fsmstate.cpp",
+        "ragel/gotablish.cpp",
+        "ragel/rubyflat.cpp",
+        "ragel/cdfgoto.h",
+        "ragel/cscodegen.h",
+        "ragel/mlflat.cpp",
+        "ragel/rubyflat.h",
+        "ragel/goftable.h",
+        "ragel/rbxgoto.cpp",
+        "ragel/csfflat.cpp",
+        "ragel/gofgoto.cpp",
+        "ragel/gofgoto.h",
+        "ragel/ragel.h",
+        "ragel/goftable.cpp",
+        "ragel/cdcodegen.cpp",
+        "ragel/rlparse.h",
+        "ragel/cdsplit.h",
+        "ragel/xmlcodegen.cpp",
+        "ragel/goipgoto.cpp",
+        "ragel/dotcodegen.h",
+        "ragel/gogoto.cpp",
+        "ragel/csflat.h",
+        "ragel/csfflat.h",
+        #"ragel/config.h.in",
+        "ragel/csipgoto.cpp",
+        "ragel/mltable.cpp",
+        "ragel/mlflat.h",
+        "ragel/csftable.cpp",
+        "ragel/cdgoto.h",
+        "ragel/goflat.cpp",
+        "ragel/rubyfflat.h",
+        "ragel/mlftable.h",
+        "ragel/rubyftable.h",
+        "ragel/fsmap.cpp",
+        "ragel/redfsm.cpp",
+        "ragel/goflat.h",
+        "ragel/parsetree.cpp",
+        "ragel/fsmmin.cpp",
+        "ragel/dotcodegen.cpp",
+        "ragel/redfsm.h",
+        "ragel/mlcodegen.cpp",
+        "ragel/cdfgoto.cpp",
+        "ragel/cssplit.cpp",
+        "ragel/cstable.cpp",
+        "ragel/javacodegen.h",
+        "ragel/parsedata.cpp",
+        "ragel/buffer.h",
+        "ragel/gogoto.h",
+        "ragel/csgoto.h",
+        "ragel/pcheck.h",
+        "ragel/rubyftable.cpp",
+        "ragel/csfgoto.h",
+        "ragel/common.h",
+        "ragel/cdftable.h",
+        "ragel/mlgoto.h",
+        "ragel/csgoto.cpp",
+        "ragel/cdflat.h",
+        "ragel/cdipgoto.h",
+        "ragel/cstable.h",
+        "ragel/gendata.h",
+        "ragel/cdfflat.cpp",
+        "ragel/gotable.cpp",
+        "ragel/cdcodegen.h",
+        "ragel/gendata.cpp",
+        "ragel/rubytable.h",
+        "ragel/csflat.cpp",
+        "ragel/inputdata.h",
+        "ragel/inputdata.cpp",
+        "ragel/rubytable.cpp",
+        "ragel/fsmattach.cpp",
+        "ragel/csipgoto.h",
+        "ragel/cscodegen.cpp",
+        "ragel/cdfflat.h",
+        "ragel/rbxgoto.h",
+        "ragel/xmlcodegen.h",
+        "ragel/gofflat.h",
+        "ragel/parsedata.h",
+        "ragel/mlfgoto.h",
+        "ragel/cdflat.cpp",
+        "ragel/config.h",
+        "ragel/rlscan.cpp",
+        "ragel/mlcodegen.h",
+        "ragel/mlfflat.cpp",
+        "ragel/mlftable.cpp",
+        "ragel/mltable.h",
+        "ragel/cdipgoto.cpp",
+        "ragel/cdftable.cpp",
+        "ragel/parsetree.h",
+        "ragel/rlscan.h",
+        "ragel/main.cpp",
+        "ragel/cssplit.h",
+        "ragel/mlfgoto.cpp",
+        "ragel/csftable.h",
+        "ragel/gotablish.h",
+        "ragel/cdgoto.cpp",
+        "aapl/avlmelkey.h",
+        "aapl/dlistmel.h",
+        "aapl/avliset.h",
+        "aapl/avlkeyless.h",
+        "aapl/sbstset.h",
+        "aapl/sbsttable.h",
+        "aapl/quicksort.h",
+        "aapl/avlitree.h",
+        "aapl/avlcommon.h",
+        "aapl/bstset.h",
+        "aapl/avlmel.h",
+        "aapl/insertsort.h",
+        "aapl/dlist.h",
+        "aapl/avlmap.h",
+        "aapl/mergesort.h",
+        "aapl/resize.h",
+        "aapl/bstcommon.h",
+        "aapl/bstmap.h",
+        "aapl/compare.h",
+        "aapl/svector.h",
+        "aapl/avlset.h",
+        "aapl/bsttable.h",
+        "aapl/avlikeyless.h",
+        "aapl/bubblesort.h",
+        "aapl/table.h",
+        "aapl/avlbasic.h",
+        "aapl/vector.h",
+        "aapl/avlimap.h",
+        "aapl/dlistval.h",
+        "aapl/dlcommon.h",
+        "aapl/avlibasic.h",
+        "aapl/sbstmap.h",
+        "aapl/avlimel.h",
+        "aapl/avlimelkey.h",
+        "aapl/avltree.h",
+    ],
+    includes = ["ragel", "aapl"],
+)
+
+config_h_contents = """
+#define PACKAGE "ragel"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT ""
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "ragel"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "ragel 6.10"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "ragel"
+
+/* Define to the home page for this package. */
+#define PACKAGE_URL ""
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "6.10"
+
+/* Version number of package */
+#define VERSION "6.10"
+"""
+
+genrule(
+    name = "gen_config_h",
+    outs = ["ragel/config.h"],
+    cmd = "(cat <<'HEREDOC'\n%s\nHEREDOC\n) > $@" % config_h_contents,
+)
diff --git a/tests/conformance_upb.c b/tests/conformance_upb.c
index ccc8a94284..e0a7d8ccd4 100644
--- a/tests/conformance_upb.c
+++ b/tests/conformance_upb.c
@@ -8,8 +8,8 @@
 #include <stdlib.h>
 #include <unistd.h>
 
-#include "conformance.upb.h"
-#include "google/protobuf/test_messages_proto3.upb.h"
+#include "conformance/conformance.upb.h"
+#include "src/google/protobuf/test_messages_proto3.upb.h"
 
 int test_count = 0;
 
diff --git a/tools/make_cmakelists.py b/tools/make_cmakelists.py
new file mode 100755
index 0000000000..30e1b93dc6
--- /dev/null
+++ b/tools/make_cmakelists.py
@@ -0,0 +1,234 @@
+#!/usr/bin/env python
+
+"""TODO(haberman): DO NOT SUBMIT without one-line documentation for make_cmakelists.
+
+TODO(haberman): DO NOT SUBMIT without a detailed description of make_cmakelists.
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import sys
+import textwrap
+
+def StripColons(deps):
+  return map(lambda x: x[1:], deps)
+
+def IsSourceFile(name):
+  return name.endswith(".c") or name.endswith(".cc")
+
+class BuildFileFunctions(object):
+  def __init__(self, converter):
+    self.converter = converter
+
+  def _add_deps(self, kwargs):
+    if "deps" not in kwargs:
+      return
+    self.converter.toplevel += "target_link_libraries(%s\n  %s)\n" % (
+        kwargs["name"],
+        "\n  ".join(StripColons(kwargs["deps"]))
+    )
+
+  def load(self, *args):
+    pass
+
+  def cc_library(self, **kwargs):
+    if kwargs["name"] == "amalgamation":
+      return
+    files = kwargs.get("srcs", []) + kwargs.get("hdrs", [])
+    self.converter.toplevel += "add_library(%s\n  %s)\n" % (
+        kwargs["name"],
+        "\n  ".join(files)
+    )
+    self._add_deps(kwargs)
+
+    # CMake wants to know if each library is C or C++.
+    # If there are only .h files, it can't infer. Assume C++.
+    if not filter(IsSourceFile, files):
+      line = "set_target_properties(%s PROPERTIES LINKER_LANGUAGE CXX)\n"
+      self.converter.toplevel += line % (kwargs["name"])
+
+  def cc_binary(self, **kwargs):
+    pass
+
+  def cc_test(self, **kwargs):
+    self.converter.toplevel += "add_executable(%s\n  %s)\n" % (
+        kwargs["name"],
+        "\n  ".join(kwargs["srcs"])
+    )
+    self.converter.toplevel += "add_test(NAME %s COMMAND %s)\n" % (
+        kwargs["name"],
+        kwargs["name"],
+    )
+
+    if "data" in kwargs:
+      for data_dep in kwargs["data"]:
+        self.converter.toplevel += textwrap.dedent("""\
+          add_custom_command(
+              TARGET %s POST_BUILD
+              COMMAND ${CMAKE_COMMAND} -E copy
+                      ${CMAKE_SOURCE_DIR}/%s
+                      ${CMAKE_CURRENT_BINARY_DIR}/%s)\n""" % (
+          kwargs["name"], data_dep, data_dep
+        ))
+
+    self._add_deps(kwargs)
+
+  def py_library(self, **kwargs):
+    pass
+
+  def py_binary(self, **kwargs):
+    pass
+
+  def lua_cclibrary(self, **kwargs):
+    pass
+
+  def lua_library(self, **kwargs):
+    pass
+
+  def lua_binary(self, **kwargs):
+    pass
+
+  def lua_test(self, **kwargs):
+    pass
+
+  def sh_test(self, **kwargs):
+    pass
+
+  def make_shell_script(self, **kwargs):
+    pass
+
+  def exports_files(self, files, **kwargs):
+    pass
+
+  def proto_library(self, **kwargs):
+    pass
+
+  def generated_file_staleness_test(self, **kwargs):
+    pass
+
+  def upb_amalgamation(self, **kwargs):
+    pass
+
+  def upb_proto_library(self, **kwargs):
+    pass
+
+  def genrule(self, **kwargs):
+    pass
+
+  def glob(*args):
+    return []
+
+
+class WorkspaceFileFunctions(object):
+  def __init__(self, converter):
+    self.converter = converter
+
+  def load(self, *args):
+    pass
+
+  def workspace(self, **kwargs):
+    self.converter.prelude += "project(%s)\n" % (kwargs["name"])
+
+  def http_archive(self, **kwargs):
+    pass
+
+  def git_repository(self, **kwargs):
+    pass
+
+
+class Converter(object):
+  def __init__(self):
+    self.prelude = ""
+    self.toplevel = ""
+    self.if_lua = ""
+
+  def convert(self):
+    return self.template % {
+        "prelude": converter.prelude,
+        "toplevel": converter.toplevel,
+    }
+
+  template = textwrap.dedent("""\
+    # This file was generated from BUILD using tools/make_cmakelists.py.
+
+    cmake_minimum_required(VERSION 3.1)
+
+    if(${CMAKE_VERSION} VERSION_LESS 3.12)
+        cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+    else()
+        cmake_policy(VERSION 3.12)
+    endif()
+
+    cmake_minimum_required (VERSION 3.0)
+    cmake_policy(SET CMP0048 NEW)
+
+    %(prelude)s
+
+    # Prevent CMake from setting -rdynamic on Linux (!!).
+    SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
+    SET(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
+
+    # Set default build type.
+    if(NOT CMAKE_BUILD_TYPE)
+      message(STATUS "Setting build type to 'RelWithDebInfo' as none was specified.")
+      set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
+          "Choose the type of build, options are: Debug Release RelWithDebInfo MinSizeRel."
+          FORCE)
+    endif()
+
+    # When using Ninja, compiler output won't be colorized without this.
+    include(CheckCXXCompilerFlag)
+    CHECK_CXX_COMPILER_FLAG(-fdiagnostics-color=always SUPPORTS_COLOR_ALWAYS)
+    if(SUPPORTS_COLOR_ALWAYS)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-color=always")
+    endif()
+
+    # Implement ASAN/UBSAN options
+    if(UPB_ENABLE_ASAN)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=address")
+      set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fsanitize=address")
+    endif()
+
+    if(UPB_ENABLE_UBSAN)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=undefined")
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=address")
+      set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fsanitize=address")
+    endif()
+
+    include_directories(.)
+    include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+    if(APPLE)
+      set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -undefined dynamic_lookup -flat_namespace")
+    elseif(UNIX)
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--build-id")
+    endif()
+
+    enable_testing()
+
+    %(toplevel)s
+
+  """)
+
+data = {}
+converter = Converter()
+
+def GetDict(obj):
+  ret = {}
+  for k in dir(obj):
+    if not k.startswith("_"):
+      ret[k] = getattr(obj, k);
+  return ret
+
+globs = GetDict(converter)
+
+execfile("WORKSPACE", GetDict(WorkspaceFileFunctions(converter)))
+execfile("BUILD", GetDict(BuildFileFunctions(converter)))
+
+with open(sys.argv[1], "w") as f:
+  f.write(converter.convert())
diff --git a/tools/staleness_test.py b/tools/staleness_test.py
new file mode 100644
index 0000000000..045cd1a319
--- /dev/null
+++ b/tools/staleness_test.py
@@ -0,0 +1,30 @@
+"""The py_test() script for generated_file_staleness_test() rules.
+
+Note that this file is preprocessed!  The INSERT_<...> text below is replaced
+with the actual list of files before we actually run the script.
+"""
+
+from __future__ import absolute_import
+
+from tools import staleness_test_lib
+import unittest
+import sys
+
+file_list = """
+  INSERT_FILE_LIST_HERE
+""".split()
+
+config = staleness_test_lib.Config(file_list)
+
+
+class TestFilesMatch(unittest.TestCase):
+
+  def testFilesMatch(self):
+    errors = staleness_test_lib.CheckFilesMatch(config)
+    self.assertFalse(errors, errors)
+
+
+if len(sys.argv) > 1 and sys.argv[1] == "--fix":
+  staleness_test_lib.FixFiles(config)
+else:
+  unittest.main()
diff --git a/tools/staleness_test_lib.py b/tools/staleness_test_lib.py
new file mode 100644
index 0000000000..6d5c3d3068
--- /dev/null
+++ b/tools/staleness_test_lib.py
@@ -0,0 +1,158 @@
+"""Shared code for validating generated_file_staleness_test() rules.
+
+This code is used by test scripts generated from
+generated_file_staleness_test() rules.
+"""
+
+from __future__ import absolute_import
+from __future__ import print_function
+
+import os
+from shutil import copyfile
+
+
+class _FilePair(object):
+  """Represents a single (target, generated) file pair."""
+
+  def __init__(self, target, generated):
+    self.target = target
+    self.generated = generated
+
+
+class Config(object):
+  """Represents the configuration for a single staleness test target."""
+
+  def __init__(self, file_list):
+    # Duplicate to avoid modifying our arguments.
+    file_list = list(file_list)
+
+    # The file list contains a few other bits of information at the end.
+    # This is packed by the code in build_defs.bzl.
+    self.target_name = file_list.pop()
+    self.package_name = file_list.pop()
+    self.pattern = file_list.pop()
+
+    self.file_list = file_list
+
+
+def _GetFilePairs(config):
+  """Generates the list of file pairs.
+
+  Args:
+    config: a Config object representing this target's config.
+
+  Returns:
+    A list of _FilePair objects.
+  """
+
+  ret = []
+
+  has_bazel_genfiles = os.path.exists("bazel-genfiles")
+
+  for filename in config.file_list:
+    target = os.path.join(config.package_name, filename)
+    generated = os.path.join(config.package_name, config.pattern % filename)
+    if has_bazel_genfiles:
+      generated = os.path.join("bazel-genfiles", generated)
+
+    # Generated files should always exist.  Blaze should guarantee this before
+    # we are run.
+    if not os.path.isfile(generated):
+      print("Generated file '%s' does not exist." % generated)
+      print("Please run this command to generate it:")
+      print("  bazel build %s:%s" % (config.package_name, config.target_name))
+    ret.append(_FilePair(target, generated))
+
+  return ret
+
+
+def _GetMissingAndStaleFiles(file_pairs):
+  """Generates lists of missing and stale files.
+
+  Args:
+    file_pairs: a list of _FilePair objects.
+
+  Returns:
+    missing_files: a list of _FilePair objects representing missing files.
+      These target files do not exist at all.
+    stale_files: a list of _FilePair objects representing stale files.
+      These target files exist but have stale contents.
+  """
+
+  missing_files = []
+  stale_files = []
+
+  for pair in file_pairs:
+    if not os.path.isfile(pair.target):
+      missing_files.append(pair)
+      continue
+
+    generated = open(pair.generated).read()
+    target = open(pair.target).read()
+    if generated != target:
+      stale_files.append(pair)
+
+  return missing_files, stale_files
+
+
+def _CopyFiles(file_pairs):
+  """Copies all generated files to the corresponding target file.
+
+  The target files must be writable already.
+
+  Args:
+    file_pairs: a list of _FilePair objects that we want to copy.
+  """
+
+  for pair in file_pairs:
+    target_dir = os.path.dirname(pair.target)
+    if not os.path.isdir(target_dir):
+      os.makedirs(target_dir)
+    copyfile(pair.generated, pair.target)
+
+
+def FixFiles(config):
+  """Implements the --fix option: overwrites missing or out-of-date files.
+
+  Args:
+    config: the Config object for this test.
+  """
+
+  file_pairs = _GetFilePairs(config)
+  missing_files, stale_files = _GetMissingAndStaleFiles(file_pairs)
+
+  _CopyFiles(stale_files + missing_files)
+
+
+def CheckFilesMatch(config):
+  """Checks whether each target file matches the corresponding generated file.
+
+  Args:
+    config: the Config object for this test.
+
+  Returns:
+    None if everything matches, otherwise a string error message.
+  """
+
+  diff_errors = []
+
+  file_pairs = _GetFilePairs(config)
+  missing_files, stale_files = _GetMissingAndStaleFiles(file_pairs)
+
+  for pair in missing_files:
+    diff_errors.append("File %s does not exist" % pair.target)
+    continue
+
+  for pair in stale_files:
+    diff_errors.append("File %s is out of date" % pair.target)
+
+  if diff_errors:
+    error_msg = "Files out of date!\n\n"
+    error_msg += "To fix run THIS command:\n"
+    error_msg += "  bazel-bin/%s/%s --fix\n\n" % (config.package_name,
+                                                  config.target_name)
+    error_msg += "Errors:\n"
+    error_msg += "  " + "\n  ".join(diff_errors)
+    return error_msg
+  else:
+    return None
diff --git a/tools/upbc b/tools/upbc
deleted file mode 100755
index bd12250c79..0000000000
--- a/tools/upbc
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/sh
-BASE=`dirname "$0"`
-export LUA_CPATH="$BASE/../lua/?.so"
-export LUA_PATH="$BASE/?.lua;$BASE/../lua/?.lua"
-lua $BASE/upbc.lua "$@"
diff --git a/tools/upbc.lua b/tools/upbc.lua
index 8ac4f735ac..adea3734b6 100644
--- a/tools/upbc.lua
+++ b/tools/upbc.lua
@@ -13,11 +13,17 @@ local make_c_api = require "make_c_api"
 local upb = require "upb"
 
 local generate_upbdefs = false
+local outdir = "."
 
-for _, argument in ipairs(arg) do
+i = 1
+while i <= #arg do
+  argument = arg[i]
   if argument.sub(argument, 1, 2) == "--" then
     if argument == "--generate-upbdefs" then
       generate_upbdefs = true
+    elseif argument == "--outdir" then
+      i = i + 1
+      outdir = arg[i]
     else
       print("Unknown flag: " .. argument)
       return 1
@@ -29,6 +35,7 @@ for _, argument in ipairs(arg) do
     end
     src = argument
   end
+  i = i + 1
 end
 
 if not src then
@@ -40,6 +47,11 @@ function strip_proto(filename)
   return string.gsub(filename, '%.proto$','')
 end
 
+local function open(filename)
+  local full_name = outdir .. "/" .. filename
+  return assert(io.open(full_name, "w"), "couldn't open " .. full_name)
+end
+
 -- Open input/output files.
 local f = assert(io.open(src, "r"), "couldn't open input file " .. src)
 local descriptor = f:read("*all")
@@ -67,8 +79,8 @@ for _, file in ipairs(files) do
 
   if generate_upbdefs then
     -- Legacy generated defs.
-    local hfile = assert(io.open(hfilename, "w"), "couldn't open " .. hfilename)
-    local cfile = assert(io.open(cfilename, "w"), "couldn't open " .. cfilename)
+    local hfile = open(hfilename)
+    local cfile = open(cfilename)
 
     local happend = dump_cinit.file_appender(hfile)
     local cappend = dump_cinit.file_appender(cfile)
@@ -90,8 +102,8 @@ for _, file in ipairs(files) do
       print(string.format("  cfilename=%s", cfilename))
     end
 
-    local hfile = assert(io.open(hfilename, "w"), "couldn't open " .. hfilename)
-    local cfile = assert(io.open(cfilename, "w"), "couldn't open " .. cfilename)
+    local hfile = open(hfilename)
+    local cfile = open(cfilename)
 
     local happend = dump_cinit.file_appender(hfile)
     local cappend = dump_cinit.file_appender(cfile)
diff --git a/upb/json/parser.c b/upb/json/parser.c
index 3ae4722377..be743662b2 100644
--- a/upb/json/parser.c
+++ b/upb/json/parser.c
@@ -2366,7 +2366,7 @@ _match:
 	break;
 	case 2:
 #line 2023 "upb/json/parser.rl"
-	{ p--; {stack[top++] = cs; cs = 24; goto _again;} }
+	{ p--; {stack[top++] = cs; cs = 24;goto _again;} }
 	break;
 	case 3:
 #line 2027 "upb/json/parser.rl"
@@ -2440,17 +2440,17 @@ _match:
 #line 2082 "upb/json/parser.rl"
 	{
         if (is_wellknown_msg(parser, UPB_WELLKNOWN_TIMESTAMP)) {
-          {stack[top++] = cs; cs = 48; goto _again;}
+          {stack[top++] = cs; cs = 48;goto _again;}
         } else if (is_wellknown_msg(parser, UPB_WELLKNOWN_DURATION)) {
-          {stack[top++] = cs; cs = 41; goto _again;}
+          {stack[top++] = cs; cs = 41;goto _again;}
         } else {
-          {stack[top++] = cs; cs = 33; goto _again;}
+          {stack[top++] = cs; cs = 33;goto _again;}
         }
       }
 	break;
 	case 21:
 #line 2093 "upb/json/parser.rl"
-	{ p--; {stack[top++] = cs; cs = 76; goto _again;} }
+	{ p--; {stack[top++] = cs; cs = 76;goto _again;} }
 	break;
 	case 22:
 #line 2098 "upb/json/parser.rl"
@@ -2538,7 +2538,9 @@ _again:
 		switch ( *__acts++ ) {
 	case 0:
 #line 2019 "upb/json/parser.rl"
-	{ p--; {cs = stack[--top]; goto _again;} }
+	{ p--; {cs = stack[--top]; 	if ( p == pe )
+		goto _test_eof;
+goto _again;} }
 	break;
 	case 26:
 #line 2111 "upb/json/parser.rl"
@@ -2564,7 +2566,7 @@ _again:
 #line 2139 "upb/json/parser.rl"
 	{ end_subobject_full(parser); }
 	break;
-#line 2568 "upb/json/parser.c"
+#line 2570 "upb/json/parser.c"
 		}
 	}
 	}
@@ -2589,7 +2591,7 @@ error:
   return p - buf;
 }
 
-bool end(void *closure, const void *hd) {
+static bool end(void *closure, const void *hd) {
   upb_json_parser *parser = closure;
 
   /* Prevent compile warning on unused static constants. */
@@ -2603,11 +2605,7 @@ bool end(void *closure, const void *hd) {
 
   parse(parser, hd, &eof_ch, 0, NULL);
 
-  return parser->current_state >= 
-#line 2608 "upb/json/parser.c"
-105
-#line 2202 "upb/json/parser.rl"
-;
+  return parser->current_state >= 105;
 }
 
 static void json_parser_reset(upb_json_parser *p) {
@@ -2622,7 +2620,7 @@ static void json_parser_reset(upb_json_parser *p) {
 
   /* Emit Ragel initialization of the parser. */
   
-#line 2626 "upb/json/parser.c"
+#line 2624 "upb/json/parser.c"
 	{
 	cs = json_start;
 	top = 0;
diff --git a/upb/json/parser.rl b/upb/json/parser.rl
index 29efd09dae..0d59082763 100644
--- a/upb/json/parser.rl
+++ b/upb/json/parser.rl
@@ -2185,7 +2185,7 @@ error:
   return p - buf;
 }
 
-bool end(void *closure, const void *hd) {
+static bool end(void *closure, const void *hd) {
   upb_json_parser *parser = closure;
 
   /* Prevent compile warning on unused static constants. */