Have all Cargo-built crates pass `--cfg cargobuild` and then add appropriate
`#[cfg]` definitions to all crates to avoid linking anything if this is passed.
This should help allow libstd to compile with both the makefiles and with Cargo.
This PR was originally going to be a "let's start running tests on MSVC" PR, but it didn't quite get to that point. It instead gets us ~80% of the way there! The steps taken in this PR are:
* Landing pads are turned on by default for 64-bit MSVC. The LLVM support is "good enough" with the caveat the destructor glue is now marked noinline. This was recommended [on the associated bug](https://llvm.org/bugs/show_bug.cgi?id=23884) as a stopgap until LLVM has a better representation for exception handling in MSVC. The consequence of this is that MSVC will have a bit of a perf hit, but there are possible routes we can take if this workaround sticks around for too long.
* The linker (`link.exe`) is now looked up in the Windows Registry if it's not otherwise available in the environment. This improves using the compiler outside of a VS shell (e.g. in a MSYS shell or in a vanilla cmd.exe shell). This also makes cross compiles via Cargo "just work" when crossing between 32 and 64 bit!
* TLS destructors were fixed to start running on MSVC (they previously weren't running at all)
* A few assorted `run-pass` tests were fixed.
* The dependency on the `rust_builtin` library was removed entirely for MSVC to try to prevent any `cl.exe` compiled objects get into the standard library. This should help us later remove any dependence on the CRT by the standard library.
* I re-added `rust_try_msvc_32.ll` for 32-bit MSVC and ensured that landing pads were turned off by default there as well.
Despite landing pads being enabled, there are still *many* failing tests on MSVC. The two major classes I've identified so far are:
* Spurious aborts. It appears that when optimizations are enabled that landing pads aren't always lined up properly, and sometimes an exception being thrown can't find the catch block down the stack, causing the program to abort. I've been working to reduce this test case but haven't been met with great success just yet.
* Parallel codegen does not work on MSVC. Our current strategy is to take the N object files emitted by the N codegen threads and use `ld -r` to assemble them into *one* object file. The MSVC linker, however, does not have this ability, and this will need to be rearchitected to work on MSVC.
I will fix parallel codegen in a future PR, and I'll also be watching LLVM closely to see if the aborts... disappear!
This library has no shims which are actually needed on Windows now, so translate
that last easy one into Rust and then don't link it at all on Windows.
This commit modifies the standard library and its dependencies to link correctly
when built against MUSL. This primarily ensures that the right libraries are
linked against and when they're linked against they're linked against
statically.
This gets rid of the 'experimental' level, removes the non-staged_api
case (i.e. stability levels for out-of-tree crates), and lets the
staged_api attributes use 'unstable' and 'deprecated' lints.
This makes the transition period to the full feature staging design
a bit nicer.
This commit merges the `rustrt` crate into `std`, undoing part of the
facade. This merger continues the paring down of the runtime system.
Code relying on the public API of `rustrt` will break; some of this API
is now available through `std::rt`, but is likely to change and/or be
removed very soon.
[breaking-change]
As discovered in #15460, a particular #[link(kind = "static", ...)] line is not
actually guaranteed to link the library at all. The reason for this is that if
the external library doesn't have any referenced symbols in the object generated
by rustc, the entire library is dropped by the linker.
For dynamic native libraries, this is solved by passing -lfoo for all downstream
compilations unconditionally. For static libraries in rlibs this is solved
because the entire archive is bundled in the rlib. The only situation in which
this was a problem was when a static native library was linked to a rust dynamic
library.
This commit brings the behavior of dylibs in line with rlibs by passing the
--whole-archive flag to the linker when linking native libraries. On OSX, this
uses the -force_load flag. This flag ensures that the entire archive is
considered candidate for being linked into the final dynamic library.
This is a breaking change because if any static library is included twice in the
same compilation unit then the linker will start emitting errors about duplicate
definitions now. The fix for this would involve only statically linking to a
library once.
Closes#15460
[breaking-change]
Not included are two required patches:
* LLVM: segmented stack support for DragonFly [1]
* jemalloc: simple configure patches
[1]: http://reviews.llvm.org/D4705
Earlier commits have established a baseline of `experimental` stability
for all crates under the facade (so their contents are considered
experimental within libstd). Since `experimental` is `allow` by
default, we should use the same baseline stability for libstd itself.
This commit adds `experimental` tags to all of the modules defined in
`std`, and `unstable` to `std` itself.
Apparently we had forgotten to do this for freebsd, causing possible problems
on FreeBSD 10. The discussion in #12324 has some more details about how it's
missing.
This will hopefully bring us closer to #11937. We're still using gcc's idea of
"startup files", but this should prevent us from leaking in dependencies that we
don't quite want (libgcc for example once compiler-rt is what we use).
Right now on linux, an empty executable with LTO still depends on librt becaues
of the clock_gettime function in rust_builtin.o, but this commit moves this
dependency into a rust function which is subject to elimination via LTO.
At the same time, this also drops libstd's dependency on librt on unices that
are not OSX because the library is only used by extra::time (and now the
dependency is listed in that module instead).
This commit alters the build process of the compiler to build a static
librustrt.a instead of a dynamic version. This means that we can stop
distributing librustrt as well as default linking against it in the compiler.
This also means that if you attempt to build rust code without libstd, it will
no longer work if there are any landing pads in play. The reason for this is
that LLVM and rustc will emit calls to the various upcalls in librustrt used to
manage exception handling. In theory we could split librustrt into librustrt and
librustupcall. We would then distribute librustupcall and link to it for all
programs using landing pads, but I would rather see just one librustrt artifact
and simplify the build process.
The major benefit of doing this is that building a static rust library for use
in embedded situations all of a sudden just became a whole lot more feasible.
Closes#3361
This commit implements the support necessary for generating both intermediate
and result static rust libraries. This is an implementation of my thoughts in
https://mail.mozilla.org/pipermail/rust-dev/2013-November/006686.html.
When compiling a library, we still retain the "lib" option, although now there
are "rlib", "staticlib", and "dylib" as options for crate_type (and these are
stackable). The idea of "lib" is to generate the "compiler default" instead of
having too choose (although all are interchangeable). For now I have left the
"complier default" to be a dynamic library for size reasons.
Of the rust libraries, lib{std,extra,rustuv} will bootstrap with an
rlib/dylib pair, but lib{rustc,syntax,rustdoc,rustpkg} will only be built as a
dynamic object. I chose this for size reasons, but also because you're probably
not going to be embedding the rustc compiler anywhere any time soon.
Other than the options outlined above, there are a few defaults/preferences that
are now opinionated in the compiler:
* If both a .dylib and .rlib are found for a rust library, the compiler will
prefer the .rlib variant. This is overridable via the -Z prefer-dynamic option
* If generating a "lib", the compiler will generate a dynamic library. This is
overridable by explicitly saying what flavor you'd like (rlib, staticlib,
dylib).
* If no options are passed to the command line, and no crate_type is found in
the destination crate, then an executable is generated
With this change, you can successfully build a rust program with 0 dynamic
dependencies on rust libraries. There is still a dynamic dependency on
librustrt, but I plan on removing that in a subsequent commit.
This change includes no tests just yet. Our current testing
infrastructure/harnesses aren't very amenable to doing flavorful things with
linking, so I'm planning on adding a new mode of testing which I believe belongs
as a separate commit.
Closes#552
