rust/src/rustllvm
bors ae5b629efd Auto merge of #51966 - alexcrichton:llvm7, r=michaelwoerister
Upgrade to LLVM's master branch (LLVM 7)

### Current status

~~Blocked on a [performance regression](https://github.com/rust-lang/rust/pull/51966#issuecomment-402320576). The performance regression has an [upstream LLVM issue](https://bugs.llvm.org/show_bug.cgi?id=38047) and has also [been bisected](https://reviews.llvm.org/D44282) to an LLVM revision.~~

Ready to merge!

---

This commit upgrades the main LLVM submodule to LLVM's current master branch.
The LLD submodule is updated in tandem as well as compiler-builtins.

Along the way support was also added for LLVM 7's new features. This primarily
includes the support for custom section concatenation natively in LLD so we now
add wasm custom sections in LLVM IR rather than having custom support in rustc
itself for doing so.

Some other miscellaneous changes are:

* We now pass `--gc-sections` to `wasm-ld`
* The optimization level is now passed to `wasm-ld`
* A `--stack-first` option is passed to LLD to have stack overflow always cause
  a trap instead of corrupting static data
* The wasm target for LLVM switched to `wasm32-unknown-unknown`.
* The syntax for aligned pointers has changed in LLVM IR and tests are updated
  to reflect this.
* ~~The `thumbv6m-none-eabi` target is disabled due to an [LLVM bug][llbug]~~

Nowadays we've been mostly only upgrading whenever there's a major release of
LLVM but enough changes have been happening on the wasm target that there's been
growing motivation for quite some time now to upgrade out version of LLD. To
upgrade LLD, however, we need to upgrade LLVM to avoid needing to build yet
another version of LLVM on the builders.

The revision of LLVM in use here is arbitrarily chosen. We will likely need to
continue to update it over time if and when we discover bugs. Once LLVM 7 is
fully released we can switch to that channel as well.

[llbug]: https://bugs.llvm.org/show_bug.cgi?id=37382

cc #50543
2018-07-11 07:20:14 +00:00
..
.editorconfig Add .editorconfig to src/rustllvm 2017-06-30 23:13:40 +03:00
ArchiveWrapper.cpp llvm6: Different return value for writeArchive 2018-01-24 07:18:02 -08:00
Linker.cpp rustc: Persist LLVM's Linker in Fat LTO 2018-02-12 09:11:06 -08:00
llvm-rebuild-trigger Update LLVM to 56c931901cfb85cd6f7ed44c7d7520a8de1edf97 2018-05-18 09:24:11 +02:00
PassWrapper.cpp Upgrade to LLVM's master branch (LLVM 7) 2018-07-10 13:43:01 -07:00
README audit LLVM C++ types in ArchiveWrapper and PassWrapper 2016-08-03 15:08:47 +03:00
rustllvm.h removed redundant header file import in rustllvm.h 2018-07-07 09:37:41 +05:30
RustWrapper.cpp still support LLVM4 for emscripten 2018-07-09 11:35:53 +02:00

This directory currently contains some LLVM support code. This will generally
be sent upstream to LLVM in time; for now it lives here.

NOTE: the LLVM C++ ABI is subject to between-version breakage and must *never*
be exposed to Rust. To allow for easy auditing of that, all Rust-exposed types
must be typedef-ed as "LLVMXyz", or "LLVMRustXyz" if they were defined here.

Functions that return a failure status and leave the error in
the LLVM last error should return an LLVMRustResult rather than an
int or anything to avoid confusion.

When translating enums, add a single `Other` variant as the first
one to allow for new variants to be added. It should abort when used
as an input.

All other types must not be typedef-ed as such.