gecko-dev/build/cargo-linker
2022-11-24 17:23:47 +00:00

59 lines
2.2 KiB
Python
Executable File

#!/usr/bin/env python3
# If you want to use a custom linker with Cargo, Cargo requires that you
# specify it in Cargo.toml or via the matching environment variable.
# Passing extra options to the linker is possible with Cargo via
# RUSTFLAGS='-C link-args', but testing showed that doing this reliably
# was difficult.
#
# Our solution to these problems is to use this wrapper script. We pass
# in the LD and the LDFLAGS to use via environment variables.
#
# * MOZ_CARGO_WRAP_LD is equivalent to CC on Unix-y platforms, and CC
# frequently has additional arguments in addition to the compiler
# itself.
#
# * MOZ_CARGO_WRAP_LDFLAGS contains space-separated arguments to pass,
# and not quoting it ensures that each of those arguments is passed
# as a separate argument to the actual LD.
#
# * In rare cases, we also need MOZ_CARGO_WRAP_LD_CXX, which is the
# equivalent of CXX, when linking C++ code. Usually, this should
# simply work by the use of CC and -lstdc++ (added by cc-rs).
# However, in the case of sanitizer runtimes, there is a separate
# runtime for C and C++ and linking C++ code with the C runtime can
# fail if the requested feature is in the C++ runtime only (bug 1747298).
import os
import sys
SANITIZERS = {
"asan": "address",
"hwasan": "hwaddress",
"lsan": "leak",
"msan": "memory",
"tsan": "thread",
}
use_clang_sanitizer = os.environ.get("MOZ_CLANG_NEWER_THAN_RUSTC_LLVM")
wrap_ld = os.environ["MOZ_CARGO_WRAP_LD"]
args = os.environ["MOZ_CARGO_WRAP_LDFLAGS"].split()
for arg in sys.argv[1:]:
if arg in ["-lc++", "-lstdc++"]:
wrap_ld = os.environ["MOZ_CARGO_WRAP_LD_CXX"]
elif use_clang_sanitizer and arg.endswith("san.a"):
# When clang is newer than rustc's LLVM, we replace rust's sanitizer
# runtimes with clang's.
filename = os.path.basename(arg)
prefix, dot, suffix = filename[:-2].rpartition(".")
if (
prefix.startswith("librustc-")
and prefix.endswith("_rt") and dot == "."
):
args.append(f"-fsanitize={SANITIZERS[suffix]}")
continue
args.append(arg)
wrap_ld = wrap_ld.split()
os.execvp(wrap_ld[0], wrap_ld + args)