I want to use rustc to compile a project written in Rust 2018 but I don't know how to switch the compiler from the default edition. The manpage for rustc mentions nothing about editions and the builtin attributes don't seem to contain anything relevant either. I'm using the Debian version of rustc (1.58.1) which was built earlier this year so it should support all three editions.
What do I need to do to get rustc to treat my code as Rust '18?
At least on Debian, the manual page that ships with Rust is incomplete. Passing --help to rustc shows that the relavent flag to set is --edition:
Usage: rustc [OPTIONS] INPUT
Options:
-h, --help Display this message
--cfg SPEC Configure the compilation environment
[...]
--edition 2015|2018|2021
Specify which edition of the compiler to use when
compiling code.
I am looking for a way to read the LLVM debug output by invoking the rust compiler (through cargo). I am especially interested in output of LLVMs ASAN.
To run a build with ASAN I can do:
cargo clean && RUSTFLAGS="-Zsanitizer=address" cargo build
but I don't know the command to get the debug log ouput.
With clang I think one can add
-mllvm -debug-only=asan
as compiler-flag.
How can I supply something like this flag through rustc?
I am using the current rust source (https://github.com/rust-lang/rust/ commit 31f5d69) to build rustc myself.
The equivalent compiler argument for rustc is
-C llvm-args=-debug-only=<LLVM DEBUG_TYPE>
The -C part gives access to the options for code generation of rust.
The llvm-args part tells rustc to forward every subsequent flag to LLVM. If I understand correctly, you can specify every LLVM option that is evaluated with cl::opt() in LLVM source code.
So the full command to build a rust application with ASAN and see only the log output of ASAN would be:
cargo clean && RUSTFLAGS="-C llvm-args=-debug-only=asan -Zsanitizer=address" cargo build
Side note: I think debug mode for LLVM must be enabled in config.toml when building rust to see the respective log output.
On Macintosh, to allow some symbols to go unlinked, it is necessary to pass -C link-args='-Wl,-undefined,dynamic_lookup' to the Rust compiler. One needs to do this when building Postgres plugins, because some of the Postgres intrinsics are only compiled into the Postgres server, and not available for linking from shared libs.
At present, the project's process is as follows:
Build is run with cargo build -v.
Failing call to rustc is copied and -C link-args='-Wl,-undefined,dynamic_lookup' added to it.
Success!
This seems like a hard sell for automation. What options are available for adding codegen flags to Rust builds through cargo?
cargo provides rustc command which allows one to pass arbitrary compiler flags. The following should do it:
% cargo rustc -- -C link-args='-Wl,-undefined,dynamic_lookup'
Basically I'm trying to compile the simplest code to Windows while I am developing on Linux.
fn main() {
println!("Hello, and bye.")
}
I found these commands by searching the internet:
rustc --target=i686-w64-mingw32-gcc main.rs
rustc --target=i686_pc_windows_gnu -C linker=i686-w64-mingw32-gcc main.rs
Sadly, none of them work. It gives me an error about the std crate missing
$ rustc --target=i686_pc_windows_gnu -C linker=i686-w64-mingw32-gcc main.rs
main.rs:1:1: 1:1 error: can't find crate for `std`
main.rs:1 fn main() {
^
error: aborting due to previous error
Is there a way to compile code on Linux that will run on Windows?
Other answers, while technically correct, are more difficult than they need to be. There's no need to use rustc (in fact it's discouraged, just use cargo), you only need rustup, cargo and your distribution's mingw-w64.
Add the target (you can also change this for whatever target you're cross compiling for):
rustup target add x86_64-pc-windows-gnu
You can build your crate easily with:
cargo build --target x86_64-pc-windows-gnu
No need for messing around with ~/.cargo/config or anything else.
EDIT: Just wanted to add that while you can use the above it can also sometimes be a headache. I wanted to add that the rust tools team also maintains a project called cross: https://github.com/rust-embedded/cross
This might be another solution that you want to look into
The Rust distribution only provides compiled libraries for the host system. However, according to Arch Linux's wiki page on Rust, you could copy the compiled libraries from the Windows packages in the download directory (note that there are i686 and x86-64 packages) in the appropriate place on your system (in /usr/lib/rustlib or /usr/local/lib/rustlib, depending on where Rust is installed), install mingw-w64-gcc and Wine and you should be able to cross-compile.
If you're using Cargo, you can tell Cargo where to look for ar and the linker by adding this to ~/.cargo/config (where $ARCH is the architecture you use):
[target.$ARCH-pc-windows-gnu]
linker = "/usr/bin/$ARCH-w64-mingw32-gcc"
ar = "/usr/$ARCH-w64-mingw32/bin/ar"
Note: the exact paths can vary based on your distribution. Check the list of files for the mingw-w64 package(s) (GCC and binutils) in your distribution.
Then you can use Cargo like this:
$ # Build
$ cargo build --release --target "$ARCH-pc-windows-gnu"
$ # Run unit tests under wine
$ cargo test --target "$ARCH-pc-windows-gnu"
UPDATE 2019-06-11
This fails for me with:
Running `rustc --crate-name animation examples/animation.rs --color always --crate-type bin --emit=dep-info,link -C debuginfo=2 --cfg 'feature="default"' -C metadata=006e668c6384c29b -C extra-filename=-006e668c6384c29b --out-dir /home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/examples --target x86_64-pc-windows-gnu -C ar=x86_64-w64-mingw32-gcc-ar -C linker=x86_64-w64-mingw32-gcc -C incremental=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/incremental -L dependency=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps -L dependency=/home/roman/projects/rust-sdl2/target/debug/deps --extern bitflags=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/libbitflags-2c7b3e3d10e1e0dd.rlib --extern lazy_static=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/liblazy_static-a80335916d5ac241.rlib --extern libc=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/liblibc-387157ce7a56c1ec.rlib --extern num=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/libnum-18ac2d75a7462b42.rlib --extern rand=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/librand-7cf254de4aeeab70.rlib --extern sdl2=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/libsdl2-3f37ebe30a087396.rlib --extern sdl2_sys=/home/roman/projects/rust-sdl2/target/x86_64-pc-windows-gnu/debug/deps/libsdl2_sys-3edefe52781ad7ef.rlib -L native=/home/roman/.cargo/registry/src/github.com-1ecc6299db9ec823/winapi-x86_64-pc-windows-gnu-0.4.0/lib`
error: linking with `x86_64-w64-mingw32-gcc` failed: exit code: 1
Maybe this will help https://github.com/rust-lang/rust/issues/44787
Static compile sdl2
There is option to static-compile sdl but it didn't work for me.
Also mixer is not included when used with bundled.
Let's cross-compile examples from rust-sdl2 project from Ubuntu to Windows x86_64
In ~/.cargo/config
[target.x86_64-pc-windows-gnu]
linker = "x86_64-w64-mingw32-gcc"
ar = "x86_64-w64-mingw32-gcc-ar"
Then run this:
sudo apt-get install gcc-mingw-w64-x86-64 -y
# use rustup to add target https://github.com/rust-lang/rustup.rs#cross-compilation
rustup target add x86_64-pc-windows-gnu
# Based on instructions from https://github.com/AngryLawyer/rust-sdl2/
# First we need sdl2 libs
# links to packages https://www.libsdl.org/download-2.0.php
sudo apt-get install libsdl2-dev -y
curl -s https://www.libsdl.org/release/SDL2-devel-2.0.9-mingw.tar.gz | tar xvz -C /tmp
# Prepare files for building
mkdir -p ~/projects
cd ~/projects
git clone https://github.com/Rust-SDL2/rust-sdl2
cd rust-sdl2
cp -r /tmp/SDL2-2.0.9/x86_64-w64-mingw32/lib/* ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-pc-windows-gnu/lib/
cp /tmp/SDL2-2.0.9/x86_64-w64-mingw32/bin/SDL2.dll .
Build examples at once
cargo build --target=x86_64-pc-windows-gnu --verbose --examples
Or stop after first fail:
echo; for i in examples/*; do [ $? -eq 0 ] && cargo build --target=x86_64-pc-windows-gnu --verbose --example $(basename $i .rs); done
Run
cargo build will put binaries in target/x86_64-pc-windows-gnu/debug/examples/
Copy needed files:
cp /tmp/SDL2-2.0.4/x86_64-w64-mingw32/bin/SDL2.dll target/x86_64-pc-windows-gnu/debug/examples/
cp assets/sine.wav target/x86_64-pc-windows-gnu/debug/examples/
Then copy directory target/x86_64-pc-windows-gnu/debug/examples/ to your Windows machine and run exe files.
Run in cmd.exe
If you want to see the console output when running exe files, you may run them from cmd.exe.
To open cmd.exe in current directory in file explorer, right click with shift on empty place in window and choose Open command window here.
Backtraces with mingw should work now - if not use msvc https://github.com/rust-lang/rust/pull/39234
There is Docker based solution called cross. All the required tools are in virtualized environment so you don't need to install additional packages for your machine. See Supported targets list.
From project's README:
Features
cross will provide all the ingredients needed for cross compilation without touching your system installation.
cross provides an environment, cross toolchain and cross compiled libraries, that produces the most portable binaries.
“cross testing”, cross can test crates for architectures other than i686 and x86_64.
The stable, beta and nightly channels are supported.
Dependencies
rustup
A Linux kernel with binfmt_misc support is required for cross testing.
One of these container engines is required. If both are installed, cross will default to docker.
Docker. Note that on Linux non-sudo users need to be in the docker group. Read the official post-installation steps. Requires version 1.24 or later.
Podman. Requires version 1.6.3 or later.
Installation
$ cargo install cross
Usage
cross has the exact same CLI as Cargo but as it relies on Docker you'll have to start the daemon before you can use it.
# (ONCE PER BOOT)
# Start the Docker daemon, if it's not already running
$ sudo systemctl start docker
# MAGIC! This Just Works
$ cross build --target aarch64-unknown-linux-gnu
# EVEN MORE MAGICAL! This also Just Works
$ cross test --target mips64-unknown-linux-gnuabi64
# Obviously, this also Just Works
$ cross rustc --target powerpc-unknown-linux-gnu --release -- -C lto
The solution that worked for me was. It is similar to one of the accepted answers but I did not require to add the toolchain.
rustup target add x86_64-pc-windows-gnu
cargo build --target x86_64-pc-windows-gnu
Refer to the documentation for more details.
I've had success on Debian (testing) without using Mingw and Wine just following the official instructions. They look scary, but in the end it didn't hurt that much.
The official instructions also contain info on how to cross-compile C/C++ code. I haven't needed that, so it's something I haven't actually tested.
A couple of remarks for individual points in the official instructions. The numbers match the numbers in the official instructions.
Debian: sudo apt-get install lld
Make a symlink named lld-link to lld somewhere in your $PATH. Example: ln -s /usr/bin/lld local_bin/lld-link
I don't cross-compile C/C++, haven't used this point personally.
This is probably the most annoying part. I installed Rust on a Windows box via rustup, and copied the libraries from the directories named in the official docs to the Linux box. Beware, there were sometimes uppercase library filenames, but lld wants them all lowercase (Windows isn't case-sensitive, Linux is). I've used the following to rename all files in current directory to lowercase:
for f in `find`; do mv -v "$f" "`echo $f | tr '[A-Z]' '[a-z]'`"; done
Personally, I've needed both Kit directories and just one of the VC dirs.
I don't cross-compile C/C++, haven't used this point personally.
Just make $LIB_ROOT in the script at the end of this post point to the lib directory from point 3.
Mandatory
I don't cross-compile C/C++, haven't used this point personally.
Depending the target architecture, either of the following:
rustup target add i686-pc-windows-msvc
rustup target add x86_64-pc-windows-msvc
For cross-building itself, I'm using the following simple script (32-bit version):
#!/bin/sh
# "cargo build" for the 32-bit Windows MSVC architecture.
# Set this to proper directory
LIB_ROOT=~/opt/rust-msvc
# The rest shouldn't need modifications
VS_LIBS="$LIB_ROOT/Microsoft Visual Studio 14.0/VC/lib/"
KIT_8_1_LIBS="$LIB_ROOT/Windows Kits/8.1/Lib/winv6.3/um/x86/"
KIT_10_LIBS="$LIB_ROOT/Windows Kits/10/Lib/10.0.10240.0/ucrt/x86/"
export LIB="$VS_LIBS;$KIT_8_1_LIBS;$KIT_10_LIBS"
cargo build --target=i686-pc-windows-msvc "$#"
I'm using the script the same way I would use cargo build
Hope that helps somebody!
How do I make cargo pass -L linker flag to rustc invocations?
It is now possible using .cargo/config.
See https://github.com/rust-lang/cargo/issues/1109 and http://doc.crates.io/config.html.
Not yet. However, you can use a custom makefile for given Cargo project instead.
For example, Servo uses the Skia library by having a Rust wrapper in the same cargo project, and a build key that calls a custom makefile.
You can do something similar in this case, for now.