# -*- 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 [],
)
