436e4fb647
Pointers for variables all need to be in the same address space for
correct compilation. Therefore ensure that even if a global variable is
created in a different address space, it is casted to the default
address space before its value is used.
This is necessary for the amdgpu target and others where the default
address space for global variables is not 0.
For example `core` does not compile in debug mode when not casting the
address space to the default one because it tries to emit the following
(simplified) LLVM IR, containing a type mismatch:
```llvm
@alloc_0 = addrspace(1) constant <{ [6 x i8] }> <{ [6 x i8] c"bit.rs" }>, align 1
@alloc_1 = addrspace(1) constant <{ ptr }> <{ ptr addrspace(1) @alloc_0 }>, align 8
; ^ here a struct containing a `ptr` is needed, but it is created using a `ptr addrspace(1)`
```
For this to compile, we need to insert a constant `addrspacecast` before
we use a global variable:
```llvm
@alloc_0 = addrspace(1) constant <{ [6 x i8] }> <{ [6 x i8] c"bit.rs" }>, align 1
@alloc_1 = addrspace(1) constant <{ ptr }> <{ ptr addrspacecast (ptr addrspace(1) @alloc_0 to ptr) }>, align 8
```
As vtables are global variables as well, they are also created with an
`addrspacecast`. In the SSA backend, after a vtable global is created,
metadata is added to it. To add metadata, we need the non-casted global
variable. Therefore we strip away an addrspacecast if there is one, to
get the underlying global.
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| library | ||
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| tests | ||
| .clang-format | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .ignore | ||
| .mailmap | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CODE_OF_CONDUCT.md | ||
| config.example.toml | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYRIGHT | ||
| INSTALL.md | ||
| LICENSE-APACHE | ||
| license-metadata.json | ||
| LICENSE-MIT | ||
| README.md | ||
| RELEASES.md | ||
| REUSE.toml | ||
| rust-bors.toml | ||
| rustfmt.toml | ||
| triagebot.toml | ||
| x | ||
| x.ps1 | ||
| x.py | ||
This is the main source code repository for Rust. It contains the compiler, standard library, and documentation.
Why Rust?
-
Performance: Fast and memory-efficient, suitable for critical services, embedded devices, and easily integrated with other languages.
-
Reliability: Our rich type system and ownership model ensure memory and thread safety, reducing bugs at compile-time.
-
Productivity: Comprehensive documentation, a compiler committed to providing great diagnostics, and advanced tooling including package manager and build tool (Cargo), auto-formatter (rustfmt), linter (Clippy) and editor support (rust-analyzer).
Quick Start
Read "Installation" from The Book.
Installing from Source
If you really want to install from source (though this is not recommended), see INSTALL.md.
Getting Help
See https://www.rust-lang.org/community for a list of chat platforms and forums.
Contributing
See CONTRIBUTING.md.
License
Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.
Trademark
The Rust Foundation owns and protects the Rust and Cargo trademarks and logos (the "Rust Trademarks").
If you want to use these names or brands, please read the media guide.
Third-party logos may be subject to third-party copyrights and trademarks. See Licenses for details.