src/rustc/std_shim/Cargo.toml

# This is a shim Cargo.toml which serves as a proxy for building the standard
# library. The reason for this is a little subtle, as one might reasonably
# expect that we just `cargo build` the standard library itself.
#
# One of the output artifacts for the standard library is a dynamic library, and
# on platforms like OSX the name of the output artifact is actually encoded into
# the library itself (similar to a soname on Linux). When the library is linked
# against, this encoded name is what's literally looked for at runtime when the
# dynamic loader is probing for libraries.
#
# Cargo, however, by default will not mangle the output filename of the
# top-level target. If we were to run `cargo build` on libstd itself, we would
# generate a file `libstd.so`. When installing, however, this file is called
# something like `libstd-abcdef0123.so`. On OSX at least this causes a failure
# at runtime because the encoded "soname" is `libstd.so`, not what the file is
# actually called.
#
# By using this shim library to build the standard library by proxy we sidestep
# this problem. The standard library is built with mangled hex already in its
# name so there's nothing extra we need to do.

[package]
name = "std_shim"
version = "0.1.0"
authors = ["The Rust Project Developers"]

[lib]
name = "std_shim"
path = "lib.rs"

[profile.release]
opt-level = 2
[profile.bench]
opt-level = 2

# These options are controlled from our rustc wrapper script, so turn them off
# here and have them controlled elsewhere.
[profile.dev]
debug = false
debug-assertions = false

[dependencies]
std = { path = "../../libstd" }

# Reexport features from std
[features]
jemalloc = ["std/jemalloc"]
debug-jemalloc = ["std/debug-jemalloc"]