rlbox.mozbuild - mozsearch

# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-

# vim: set filetype=python:

# This Source Code Form is subject to the terms of the Mozilla Public

# License, v. 2.0. If a copy of the MPL was not distributed with this

# file, You can obtain one at http://mozilla.org/MPL/2.0/.

@template

def RLBoxLibrary(name, use_segue=True):

    WASM_SOURCES += [

        "/memory/mozalloc/mozalloc.cpp",

        "/third_party/rlbox_wasm2c_sandbox/c_src/wasm2c_sandbox_wrapper.c",

    if CONFIG["DEVELOPER_OPTIONS"]:

        wasm_sources = sorted(f"!{name}.wasm_{n}.c" for n in range(16))

    else:

        wasm_sources = [f"!{name}.wasm.c"]

    SOURCES += wasm_sources

    SOURCES += ["/third_party/wasm2c/wasm2c/wasm-rt-impl.c"]

    SOURCES += ["/third_party/wasm2c/wasm2c/wasm-rt-mem-impl.c"]

    # Configuration for the wasm2c runtime used by RLBox

    # Enable SIMD autovectorization

    if CONFIG["WASM_CC_VERSION"] and int(CONFIG["WASM_CC_VERSION"].split(".")[0]) >= 11:

        WASM_CXXFLAGS += ["-msimd128"]

    # Use a mmap style allocation

    DEFINES["WASM_RT_USE_MMAP"] = 1

    # Don't use internal signal handler as Firefox already provides one

    DEFINES["WASM_RT_SKIP_SIGNAL_RECOVERY"] = 1

    # We provide a custom trap handler that calls MOZ_CRASH

    DEFINES["WASM_RT_TRAP_HANDLER"] = "moz_wasm2c_trap_handler"

    # Don't limit the nested call depth

    DEFINES["WASM_RT_NONCONFORMING_UNCHECKED_STACK_EXHAUSTION"] = 1

    # Configure the wasm runtime to invoke a callback when a Wasm memory growth

    # fails inside the sandbox. This information is used to annotate crash reports.

    DEFINES["WASM_RT_GROW_FAILED_HANDLER"] = "moz_wasm2c_memgrow_failed"

    for source in wasm_sources:

        SOURCES[source].flags += ["-Wno-unused"]

    # Use Segue optimization. Since this requires passing the "-mfsgsbase", we

    # restrict this to compilers and architectures that support this flag.

    # Manually exclude android for now due to bug in upstream wasm2c support

    if (

        use_segue

        and CONFIG["CC_TYPE"] in ("clang", "gcc")

        and CONFIG["TARGET_CPU"] == "x86_64"

        and CONFIG["OS_TARGET"] != "Android"

        # https://github.com/llvm/llvm-project/issues/124238

        and not (CONFIG["MOZ_ASAN"] or CONFIG["MOZ_TSAN"])

):

        # Setting WASM_RT_ALLOW_SEGUE means Segue is used on supported

        # OS/compiler/Arch combinations. For example, it is used for

        # Linux/clang/x86_64 but not on Windows

        DEFINES["WASM_RT_ALLOW_SEGUE"] = 1

        # Segue can assume there is no other use of the segment register by the

        # application. This is fine as the System V ABI for x86_64 systems does

        # not use the gs register for any other purpose.

        DEFINES["WASM_RT_SEGUE_FREE_SEGMENT"] = 1

        # Add a compiler flag for the wasm2c produced file to enable use of

        # wrgsbase64 instruction via intrinsics. While this instruction is

        # available only on CPUs starting Ivybridge, the wasm2c runtime checks for

        # support before using this instruction. Thus, enabling this flag does not

        # introduce a dependency on newer CPUs to Firefox.

        CFLAGS += ["-mfsgsbase"]

    WASM_DEFINES["MOZ_IN_WASM_SANDBOX"] = True

    if CONFIG["ENABLE_CLANG_PLUGIN"]:

        WASM_DEFINES["MOZ_CLANG_PLUGIN"] = True

    SANDBOXED_WASM_LIBRARY_NAME = f"{name}.wasm"

    # Ideally we'd also list {name}.wasm.h as an output, but that would put the

    # generation in export rather than pre-compile, and we prefer the latter.

    GeneratedFile(

        f"{name}.wasm.c",

        script="/config/wasm2c.py",

        entry_point="wasm2c",

        inputs=["!/dist/host/bin/wasm2c" + CONFIG["HOST_BIN_SUFFIX"], f"!{name}.wasm"],

        flags=["--num-outputs", len(wasm_sources)] if len(wasm_sources) > 1 else [],