mirror of
https://github.com/denoland/deno.git
synced 2024-11-14 16:33:45 -05:00
203 lines
8.3 KiB
Python
Executable file
203 lines
8.3 KiB
Python
Executable file
#!/usr/bin/env python
|
|
# Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
|
|
#
|
|
# The Rust compiler normally builds source code directly into an executable.
|
|
# Internally, object code is produced, and then the (system) linker is called,
|
|
# but this all happens under the covers.
|
|
#
|
|
# However Deno's build system uses it's own linker. For it to successfully
|
|
# produce an executable from rustc-generated object code, it needs to link
|
|
# with a dozen or so "built-in" Rust libraries (as in: not Cargo crates),
|
|
# and we need to tell the linker which and where those .rlibs are.
|
|
#
|
|
# Hard-coding these libraries into the GN configuration isn't possible: the
|
|
# required .rlib files have some sort of hash code in their file name, and their
|
|
# location depends on how Rust is set up, and which toolchain is active.
|
|
#
|
|
# So instead, we have this script: it writes a list of linker options (ldflags)
|
|
# to stdout, separated by newline characters. It is called from `rust.gni` when
|
|
# GN is generating ninja files (it doesn't run in the build phase).
|
|
#
|
|
# There is no official way through which rustc will give us the information
|
|
# we need, so a "back door" is used. We tell `rustc` to compile a (dummy)
|
|
# program, and to use a custom linker. This "linker" doesn't actually link
|
|
# anything; it just dumps it's argv to a temporary file. When rustc is done,
|
|
# this script then reads the linker arguments from that temporary file, and
|
|
# then filters it to remove flags that are irrelevant or undesirable.
|
|
|
|
import json
|
|
import re
|
|
import sys
|
|
import os
|
|
from os import path
|
|
import subprocess
|
|
import tempfile
|
|
|
|
|
|
def capture_linker_args(argsfile_path):
|
|
with open(argsfile_path, "wb") as argsfile:
|
|
argsfile.write("\n".join(sys.argv[1:]))
|
|
|
|
|
|
def get_ldflags(rustc_args):
|
|
# Prepare the environment for rustc.
|
|
rustc_env = os.environ.copy()
|
|
|
|
# We'll capture the arguments rustc passes to the linker by telling it
|
|
# that this script *is* the linker.
|
|
# On Posix systems, this file is directly executable thanks to it's shebang.
|
|
# On Windows, we use a .cmd wrapper file.
|
|
if os.name == "nt":
|
|
rustc_linker_base, _rustc_linker_ext = path.splitext(__file__)
|
|
rustc_linker = rustc_linker_base + ".cmd"
|
|
else:
|
|
rustc_linker = __file__
|
|
|
|
# Make sure that when rustc invokes this script, it uses the same version
|
|
# of the Python interpreter as we're currently using. On Posix systems this
|
|
# is done making the Python directory the first element of PATH.
|
|
# On Windows, the wrapper script uses the PYTHON_EXE environment variable.
|
|
if os.name == "nt":
|
|
rustc_env["PYTHON_EXE"] = sys.executable
|
|
else:
|
|
python_dir = path.dirname(sys.executable)
|
|
rustc_env["PATH"] = python_dir + path.pathsep + os.environ["PATH"]
|
|
|
|
# Create a temporary file to write captured Rust linker arguments to.
|
|
# Unfortunately we can't use tempfile.NamedTemporaryFile here, because the
|
|
# file it creates can't be open in two processes at the same time.
|
|
argsfile_fd, argsfile_path = tempfile.mkstemp()
|
|
rustc_env["ARGSFILE_PATH"] = argsfile_path
|
|
|
|
try:
|
|
# Build the rustc command line.
|
|
# * `-Clinker=` tells rustc to use our fake linker.
|
|
# * `-Csave-temps` prevents rustc from deleting object files after
|
|
# linking. We need to preserve the extra object file with allocator
|
|
# symbols (`_rust_alloc` etc.) in it that rustc produces.
|
|
rustc_cmd = [
|
|
"rustc",
|
|
"-Clinker=" + rustc_linker,
|
|
"-Csave-temps",
|
|
] + rustc_args
|
|
|
|
# Spawn the rust compiler.
|
|
rustc_proc = subprocess.Popen(
|
|
rustc_cmd,
|
|
env=rustc_env,
|
|
stdout=subprocess.PIPE,
|
|
stderr=subprocess.STDOUT)
|
|
|
|
# Forward rustc's output to stderr.
|
|
for line in rustc_proc.stdout:
|
|
# Suppress the warning:
|
|
# `-C save-temps` might not produce all requested temporary
|
|
# products when incremental compilation is enabled.
|
|
# It's pointless, because incremental compilation is disabled.
|
|
if re.match(r"^warning:.*save-temps.*incremental compilation",
|
|
line):
|
|
continue
|
|
# Also, do not write completely blank lines to stderr.
|
|
if line.strip() == "":
|
|
continue
|
|
sys.stderr.write(line)
|
|
|
|
# The rustc process should return zero. If not, raise an exception.
|
|
rustc_retcode = rustc_proc.wait()
|
|
if rustc_retcode != 0:
|
|
raise subprocess.CalledProcessError(rustc_retcode, rustc_cmd)
|
|
|
|
# Read captured linker arguments from argsfile.
|
|
argsfile_size = os.fstat(argsfile_fd).st_size
|
|
argsfile_content = os.read(argsfile_fd, argsfile_size)
|
|
args = argsfile_content.split("\n")
|
|
|
|
except OSError as e: # Note: in python 3 this will be a FileNotFoundError.
|
|
print "Error executing rustc command (is rust installed?):"
|
|
print " ".join(rustc_cmd) + "\n"
|
|
raise e
|
|
|
|
finally:
|
|
# Close and delete the temporary file.
|
|
os.close(argsfile_fd)
|
|
os.unlink(argsfile_path)
|
|
|
|
# From the list of captured linker arguments, build the list of ldflags that
|
|
# we actually need.
|
|
ldflags = []
|
|
next_arg_is_flag_value = False
|
|
for arg in args:
|
|
# Note that within the following if/elif blocks, `pass` means that
|
|
# that captured arguments gets included in `ldflags`. The final `else`
|
|
# clause filters out unrecognized/unwanted flags.
|
|
if next_arg_is_flag_value:
|
|
# We're looking at a value that follows certain parametric flags,
|
|
# e.g. the path in '-L <path>'.
|
|
next_arg_is_flag_value = False
|
|
elif arg.endswith(".rlib"):
|
|
# Built-in Rust library, e.g. `libstd-8524caae8408aac2.rlib`.
|
|
pass
|
|
elif re.match(r"^empty_crate\.[a-z0-9]+\.rcgu.o$", arg):
|
|
# This file is needed because it contains certain allocator
|
|
# related symbols (e.g. `__rust_alloc`, `__rust_oom`).
|
|
# The Rust compiler normally generates this file just before
|
|
# linking an executable. We pass `-Csave-temps` to rustc so it
|
|
# doesn't delete the file when it's done linking.
|
|
pass
|
|
elif arg.endswith(".crate.allocator.rcgu.o"):
|
|
# Same as above, but for rustc version 1.29.0 and older.
|
|
pass
|
|
elif arg.endswith(".lib") and not arg.startswith("msvcrt"):
|
|
# Include most Windows static/import libraries (e.g. `ws2_32.lib`).
|
|
# However we ignore Rusts choice of C runtime (`mvcrt*.lib`).
|
|
# Rust insists on always using the release "flavor", even in debug
|
|
# mode, which causes conflicts with other libraries we link with.
|
|
pass
|
|
elif arg.upper().startswith("/LIBPATH:"):
|
|
# `/LIBPATH:<path>`: Linker search path (Microsoft style).
|
|
pass
|
|
elif arg == "-l" or arg == "-L":
|
|
# `-l <name>`: Link with library (GCC style).
|
|
# `-L <path>`: Linker search path (GCC style).
|
|
next_arg_is_flag_value = True # Ensure flag argument is captured.
|
|
elif arg == "-Wl,--start-group" or arg == "-Wl,--end-group":
|
|
# Start or end of an archive group (GCC style).
|
|
pass
|
|
else:
|
|
# Not a flag we're interested in -- don't add it to ldflags.
|
|
continue
|
|
|
|
ldflags += [arg]
|
|
|
|
return ldflags
|
|
|
|
|
|
def get_version():
|
|
version = subprocess.check_output(["rustc", "--version"])
|
|
version = version.strip() # Remove trailing newline.
|
|
return version
|
|
|
|
|
|
def main():
|
|
# If ARGSFILE_PATH is set this script is being invoked by rustc, which
|
|
# thinks we are a linker. All we do now is write our argv to the specified
|
|
# file and exit. Further processing is done by our grandparent process,
|
|
# also this script but invoked by gn.
|
|
argsfile_path = os.getenv("ARGSFILE_PATH")
|
|
if argsfile_path is not None:
|
|
return capture_linker_args(argsfile_path)
|
|
|
|
empty_crate_source = path.join(path.dirname(__file__), "empty_crate.rs")
|
|
|
|
info = {
|
|
"version": get_version(),
|
|
"ldflags_bin": get_ldflags([empty_crate_source]),
|
|
"ldflags_test": get_ldflags([empty_crate_source, "--test"])
|
|
}
|
|
|
|
# Write the information dict as a json object.
|
|
json.dump(info, sys.stdout)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
sys.exit(main())
|