The `rsbegin.o` and `rsend.o` build products should not be generated
on non WinGnu platforms.
This is another path to resolving #30063 for non win-gnu targets.
(And it won't require a snapshot, unlike PR #30208.)
Note: for now, this change only affects `-windows-gnu` builds.
So why was this `libgcc` dylib dependency needed in the first place?
The stack unwinder needs to know about locations of unwind tables of all the modules loaded in the current process. The easiest portable way of achieving this is to have each module register itself with the unwinder when loaded into the process. All modules compiled by GCC do this by calling the __register_frame_info() in their startup code (that's `crtbegin.o` and `crtend.o`, which are automatically linked into any gcc output).
Another important piece is that there should be only one copy of the unwinder (and thus unwind tables registry) in the process. This pretty much means that the unwinder must be in a shared library (unless everything is statically linked).
Now, Rust compiler tries very hard to make sure that any given Rust crate appears in the final output just once. So if we link the unwinder statically to one of Rust's crates, everything should be fine.
Unfortunately, GCC startup objects are built under assumption that `libgcc` is the one true place for the unwind info registry, so I couldn't find any better way than to replace them. So out go `crtbegin`/`crtend`, in come `rsbegin`/`rsend`!
A side benefit of this change is that rustc is now more in control of the command line that goes to the linker, so we could stop using `gcc` as the linker driver and just invoke `ld` directly.
Since it isn't possible to disable linkage of just GCC startup objects, we now need logic for finding libc installation directory and copying the required startup files (e.g. crt2.o) to rustlib directory.
Bonus change: use the `-nodefaultlibs` flag on Windows, thus paving the way to direct linker invocation.
* Don't pass `-mno-compact-eh`, apparently not all compilers have this?
* Don't pass `+o32`, apparently LLVm doesn't recognize this
* Use `mipsel-linux-gnu` as a prefix instead of `mipsel-unknown-linux-gnu`, this
matches the ubuntu package at least!
For most parts, rumprun currently looks like NetBSD, as they share the same
libc and drivers. However, being a unikernel, rumprun does not support
process management, signals or virtual memory, so related functions
might fail at runtime. Stack guards are disabled exactly for this reason.
Code for rumprun is always cross-compiled, it uses always static
linking and needs a custom linker.
This commit modifies the configure script and our makefiles to support building
32-bit MSVC targets. The MSVC toolchain is now parameterized over whether it can
produce a 32-bit or 64-bit binary. The configure script was updated to export
more variables at configure time, and the makefiles were rejiggered to
selectively reexport the relevant environment variables for the applicable
targets they're going to run for.
Right now the distribution tarball for MSVC only includes the *.dll files for
the supporting libraries, but not the corresponding *.lib files which allow
actually linking to the dll. This means that the current MSVC nightlies cannot
produce dynamically linked binaries as the *.lib files are not available to link
against.
This commit modifies the `LIB_GLOB` used to copy the files around to include the
`lib` variant of the `dll`.
On MSVC there are two ways that the CRT can be linked, either statically or
dynamically. Each object file produced by the compiler is compiled against
msvcrt (a dll) or libcmt (a static library). When the linker is dealing with
more than one object file, it requires that all object files link to the same
CRT, or else the linker will spit out some errors.
For now, compile code with `-MD` as it seems to appear more often in C libraries
so we'll stick with the same trend.
Now that MSVC support has landed in the most recent nightlies we can now have
MSVC bootstrap itself without going through a GNU compiler first. Unfortunately,
however, the bootstrap currently fails due to the compiler not being able to
find the llvm-ar.exe tool during the stage0 libcore compile. The compiler cannot
find this tool because it's looking inside a directory that does not exist:
$SYSROOT/rustlib/x86_64-pc-windows-gnu/bin
The `gnu` on this triple is because the bootstrap compiler's host architecture
is GNU. The build system, however, only arranges for the llvm-ar.exe tool to be
available in this location:
$SYSROOT/rustlib/x86_64-pc-windows-msvc/bin
To resolve this discrepancy, the build system has been modified to understand
triples that are bootstrapped from another triple, and in this case copy the
native tools to the right location.
Now that MSVC support has landed in the most recent nightlies we can now have
MSVC bootstrap itself without going through a GNU compiler first. Unfortunately,
however, the bootstrap currently fails due to the compiler not being able to
find the llvm-ar.exe tool during the stage0 libcore compile. The compiler cannot
find this tool because it's looking inside a directory that does not exist:
$SYSROOT/rustlib/x86_64-pc-windows-gnu/bin
The `gnu` on this triple is because the bootstrap compiler's host architecture
is GNU. The build system, however, only arranges for the llvm-ar.exe tool to be
available in this location:
$SYSROOT/rustlib/x86_64-pc-windows-msvc/bin
To resolve this discrepancy, the build system has been modified to understand
triples that are bootstrapped from another triple, and in this case copy the
native tools to the right location.
The changes scaled back in 4cc025d8 were a little too aggressive and broke a
bunch of cross compilations by not defining the `LINK_$(1)` variable for all
targets. This commit ensures that the variable is defined for all targets by
defaulting it to the normal compiler if it's not already defined (it's only
defined specially for MSVC).
Closes#25723
This commit updates the `dist` target for MSVC to not build the mingw components
and to also ensure that the `llvm-ar.exe` binary is ferried along into the right
location for installs.
Windows needs explicit exports of functions from DLLs but LLVM does not mention
any of its symbols as being export-able from a DLL. The compiler, however,
relies on being able to use LLVM symbols across DLL boundaries so we need to
force many of LLVM's symbols to be exported from `rustc_llvm.dll`. This commit
adds support for generation of a `rustc_llvm.def` file which is passed along to
the linker when generating `rustc_llvm.dll` which should keep all these symbols
exportable and usable.
The compiler will require that `llvm-ar.exe` be available for MSVC-targeting
builds (more comments on this soon), so this commit adds support for targets to
depend on LLVM tools. The `core` library for MSVC depends on `llvm-ar.exe` which
will be copied into place for the target before the compiler starts to run.
Note that these targets all depend on `llvm-config.exe` to ensure that they're
built before they're attempted to be copied.
This commit starts to add MSVC support to the ./configure script to enable the
build system to detect and build an MSVC target with the cl.exe compiler and
toolchain. The primary change here is a large sanity check when an MSVC target
is requested (and currently only `x86_64-pc-windows-msvc` is recognized).
When building an MSVC target, the configure script either requires the
`--msvc-root` argument or for `cl.exe` to be in `PATH`. It also requires that if
in the path `cl.exe` is the 64-bit version of the compiler.
Once detected the configure script will run the `vcvarsall.bat` script provided
by Visual Studio to learn about the `INCLUDE` and `LIB` variables needed by the
`cl.exe` compiler to run (the default include/lib paths for the
compiler/linker). These variables are then reexported when running `make` to
ensure that our own compiles are running the same toolchain.
The purpose of this detection and environment variable scraping is to avoid
requiring the build itself to be run inside of a `cmd.exe` shell but rather
allow it to run in the currently expected MinGW/MSYS shell.
This commit adds support to the makefiles, configuration script, and build
system to understand MUSL. This is broken up into a few parts:
* Any target of the form `*-musl` requires the `--musl-root` option to
`./configure` which will indicate the root of the MUSL installation. It is
also expected that there is a libunwind build inside of that installation
built against that MUSL.
* Objects from MUSL are copied into the build tree for Rust to be statically
linked into the appropriate Rust library.
* Objects for binary startup and shutdown are included in each Rust installation
by default for MUSL. This requires MUSL to only be installed on the machine
compiling rust. Only a linker will be necessary for compiling against MUSL on
a target machine.
Eventually a MUSL and/or libunwind build may be integrated by default into the
build but for now they are just always assumed to exist externally.
Initial support for aarch64-linux-android (#18920)
- Add new configuration files
- Modify some options to compile & link succesfully.
(PIE, disable tls on jemalloc, modify some external function linkage, ..)
- To build, refer to https://github.com/rust-lang/rust/wiki/Doc-building-for-android.
(tested with platform=21 and toolchain=aarch64-linux-android-4.9)
Removed use of unused LDPATH variable on Windows as is done for other platforms, and added GCC flag to ensure MINGW's ANSI compatible STDIO functions are used wherever available (required by jemalloc).
Without these changes it ends up setting the PATH twice, and the second time the PATH begins with `:` which is invalid. Also the regular msvcrt printf-like functions would be used which don't understand stuff like %hhd and %z which jemalloc uses.
This change ought not to make any difference to the output but it fixes the build process for me since at least my build environment couldn't handle that broken path caused by LDPATH being empty.
Removes all target-specific knowledge from rustc. Some targets have changed
during this, but none of these should be very visible outside of
cross-compilation. The changes make our targets more consistent.
iX86-unknown-linux-gnu is now only available as i686-unknown-linux-gnu. We
used to accept any value of X greater than 1. i686 was released in 1995, and
should encompass the bare minimum of what Rust supports on x86 CPUs.
The only two windows targets are now i686-pc-windows-gnu and
x86_64-pc-windows-gnu.
The iOS target has been renamed from arm-apple-ios to arm-apple-darwin.
A complete list of the targets we accept now:
arm-apple-darwin
arm-linux-androideabi
arm-unknown-linux-gnueabi
arm-unknown-linux-gnueabihf
i686-apple-darwin
i686-pc-windows-gnu
i686-unknown-freebsd
i686-unknown-linux-gnu
mips-unknown-linux-gnu
mipsel-unknown-linux-gnu
x86_64-apple-darwin
x86_64-unknown-freebsd
x86_64-unknown-linux-gnu
x86_64-pc-windows-gnu
Closes#16093
[breaking-change]
