tor-browser

The Tor Browser
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rlbox.mozbuild (3838B)


      1 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
      2 # vim: set filetype=python:
      3 # This Source Code Form is subject to the terms of the Mozilla Public
      4 # License, v. 2.0. If a copy of the MPL was not distributed with this
      5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
      6 
      7 
      8 @template
      9 def RLBoxLibrary(name, use_segue=True):
     10     WASM_SOURCES += [
     11         "/memory/mozalloc/mozalloc.cpp",
     12         "/third_party/rlbox_wasm2c_sandbox/c_src/wasm2c_sandbox_wrapper.c",
     13     ]
     14 
     15     if CONFIG["DEVELOPER_OPTIONS"]:
     16         wasm_sources = sorted(f"!{name}.wasm_{n}.c" for n in range(16))
     17     else:
     18         wasm_sources = [f"!{name}.wasm.c"]
     19     SOURCES += wasm_sources
     20     SOURCES += ["/third_party/wasm2c/wasm2c/wasm-rt-impl.c"]
     21     SOURCES += ["/third_party/wasm2c/wasm2c/wasm-rt-mem-impl.c"]
     22 
     23     # Configuration for the wasm2c runtime used by RLBox
     24 
     25     # Enable SIMD autovectorization
     26     if CONFIG["WASM_CC_VERSION"] and int(CONFIG["WASM_CC_VERSION"].split(".")[0]) >= 11:
     27         WASM_CXXFLAGS += ["-msimd128"]
     28 
     29     # Use a mmap style allocation
     30     DEFINES["WASM_RT_USE_MMAP"] = 1
     31 
     32     # Don't use internal signal handler as Firefox already provides one
     33     DEFINES["WASM_RT_SKIP_SIGNAL_RECOVERY"] = 1
     34 
     35     # We provide a custom trap handler that calls MOZ_CRASH
     36     DEFINES["WASM_RT_TRAP_HANDLER"] = "moz_wasm2c_trap_handler"
     37 
     38     # Don't limit the nested call depth
     39     DEFINES["WASM_RT_NONCONFORMING_UNCHECKED_STACK_EXHAUSTION"] = 1
     40 
     41     # Configure the wasm runtime to invoke a callback when a Wasm memory growth
     42     # fails inside the sandbox. This information is used to annotate crash reports.
     43     DEFINES["WASM_RT_GROW_FAILED_HANDLER"] = "moz_wasm2c_memgrow_failed"
     44 
     45     for source in wasm_sources:
     46         SOURCES[source].flags += ["-Wno-unused"]
     47 
     48     # Use Segue optimization. Since this requires passing the "-mfsgsbase", we
     49     # restrict this to compilers and architectures that support this flag.
     50     # Manually exclude android for now due to bug in upstream wasm2c support
     51     if (
     52         use_segue
     53         and CONFIG["CC_TYPE"] in ("clang", "gcc")
     54         and CONFIG["TARGET_CPU"] == "x86_64"
     55         and CONFIG["OS_TARGET"] != "Android"
     56         # https://github.com/llvm/llvm-project/issues/124238
     57         and not (CONFIG["MOZ_ASAN"] or CONFIG["MOZ_TSAN"])
     58     ):
     59         # Setting WASM_RT_ALLOW_SEGUE means Segue is used on supported
     60         # OS/compiler/Arch combinations. For example, it is used for
     61         # Linux/clang/x86_64 but not on Windows
     62         DEFINES["WASM_RT_ALLOW_SEGUE"] = 1
     63 
     64         # Segue can assume there is no other use of the segment register by the
     65         # application. This is fine as the System V ABI for x86_64 systems does
     66         # not use the gs register for any other purpose.
     67         DEFINES["WASM_RT_SEGUE_FREE_SEGMENT"] = 1
     68 
     69         # Add a compiler flag for the wasm2c produced file to enable use of
     70         # wrgsbase64 instruction via intrinsics. While this instruction is
     71         # available only on CPUs starting Ivybridge, the wasm2c runtime checks for
     72         # support before using this instruction. Thus, enabling this flag does not
     73         # introduce a dependency on newer CPUs to Firefox.
     74         CFLAGS += ["-mfsgsbase"]
     75 
     76     WASM_DEFINES["MOZ_IN_WASM_SANDBOX"] = True
     77     if CONFIG["ENABLE_CLANG_PLUGIN"]:
     78         WASM_DEFINES["MOZ_CLANG_PLUGIN"] = True
     79 
     80     SANDBOXED_WASM_LIBRARY_NAME = f"{name}.wasm"
     81 
     82     # Ideally we'd also list {name}.wasm.h as an output, but that would put the
     83     # generation in export rather than pre-compile, and we prefer the latter.
     84     GeneratedFile(
     85         f"{name}.wasm.c",
     86         script="/config/wasm2c.py",
     87         entry_point="wasm2c",
     88         inputs=["!/dist/host/bin/wasm2c" + CONFIG["HOST_BIN_SUFFIX"], f"!{name}.wasm"],
     89         flags=["--num-outputs", len(wasm_sources)] if len(wasm_sources) > 1 else [],
     90     )