-
Notifications
You must be signed in to change notification settings - Fork 13k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Auto merge of #23593 - Manishearth:rollup, r=Manishearth
(yay, no Saturday)
- Loading branch information
Showing
19 changed files
with
347 additions
and
205 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,128 @@ | ||
An informal guide to reading and working on the rustc compiler. | ||
================================================================== | ||
|
||
If you wish to expand on this document, or have a more experienced | ||
Rust contributor add anything else to it, please get in touch: | ||
|
||
* http://internals.rust-lang.org/ | ||
* https://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust | ||
|
||
or file a bug: | ||
|
||
https://github.com/rust-lang/rust/issues | ||
|
||
Your concerns are probably the same as someone else's. | ||
|
||
The crates of rustc | ||
=================== | ||
|
||
Rustc consists of a number of crates, including `libsyntax`, | ||
`librustc`, `librustc_back`, `librustc_trans`, and `librustc_driver` | ||
(the names and divisions are not set in stone and may change; | ||
in general, a finer-grained division of crates is preferable): | ||
|
||
- `libsyntax` contains those things concerned purely with syntax – | ||
that is, the AST, parser, pretty-printer, lexer, macro expander, and | ||
utilities for traversing ASTs – are in a separate crate called | ||
"syntax", whose files are in `./../libsyntax`, where `.` is the | ||
current directory (that is, the parent directory of front/, middle/, | ||
back/, and so on). | ||
|
||
- `librustc` (the current directory) contains the high-level analysis | ||
passes, such as the type checker, borrow checker, and so forth. | ||
It is the heart of the compiler. | ||
|
||
- `librustc_back` contains some very low-level details that are | ||
specific to different LLVM targets and so forth. | ||
|
||
- `librustc_trans` contains the code to convert from Rust IR into LLVM | ||
IR, and then from LLVM IR into machine code, as well as the main | ||
driver that orchestrates all the other passes and various other bits | ||
of miscellany. In general it contains code that runs towards the | ||
end of the compilation process. | ||
|
||
- `librustc_driver` invokes the compiler from `libsyntax`, then the | ||
analysis phases from `librustc`, and finally the lowering and | ||
codegen passes from `librustc_trans`. | ||
|
||
Roughly speaking the "order" of the three crates is as follows: | ||
|
||
libsyntax -> librustc -> librustc_trans | ||
| | | ||
+-----------------+-------------------+ | ||
| | ||
librustc_driver | ||
|
||
|
||
Modules in the rustc crate | ||
========================== | ||
|
||
The rustc crate itself consists of the following submodules | ||
(mostly, but not entirely, in their own directories): | ||
|
||
- session: options and data that pertain to the compilation session as | ||
a whole | ||
- middle: middle-end: name resolution, typechecking, LLVM code | ||
generation | ||
- metadata: encoder and decoder for data required by separate | ||
compilation | ||
- plugin: infrastructure for compiler plugins | ||
- lint: infrastructure for compiler warnings | ||
- util: ubiquitous types and helper functions | ||
- lib: bindings to LLVM | ||
|
||
The entry-point for the compiler is main() in the librustc_trans | ||
crate. | ||
|
||
The 3 central data structures: | ||
------------------------------ | ||
|
||
1. `./../libsyntax/ast.rs` defines the AST. The AST is treated as | ||
immutable after parsing, but it depends on mutable context data | ||
structures (mainly hash maps) to give it meaning. | ||
|
||
- Many – though not all – nodes within this data structure are | ||
wrapped in the type `spanned<T>`, meaning that the front-end has | ||
marked the input coordinates of that node. The member `node` is | ||
the data itself, the member `span` is the input location (file, | ||
line, column; both low and high). | ||
|
||
- Many other nodes within this data structure carry a | ||
`def_id`. These nodes represent the 'target' of some name | ||
reference elsewhere in the tree. When the AST is resolved, by | ||
`middle/resolve.rs`, all names wind up acquiring a def that they | ||
point to. So anything that can be pointed-to by a name winds | ||
up with a `def_id`. | ||
|
||
2. `middle/ty.rs` defines the datatype `sty`. This is the type that | ||
represents types after they have been resolved and normalized by | ||
the middle-end. The typeck phase converts every ast type to a | ||
`ty::sty`, and the latter is used to drive later phases of | ||
compilation. Most variants in the `ast::ty` tag have a | ||
corresponding variant in the `ty::sty` tag. | ||
|
||
3. `./../librustc_llvm/lib.rs` defines the exported types | ||
`ValueRef`, `TypeRef`, `BasicBlockRef`, and several others. | ||
Each of these is an opaque pointer to an LLVM type, | ||
manipulated through the `lib::llvm` interface. | ||
|
||
|
||
Control and information flow within the compiler: | ||
------------------------------------------------- | ||
|
||
- main() in lib.rs assumes control on startup. Options are | ||
parsed, platform is detected, etc. | ||
|
||
- `./../libsyntax/parse/parser.rs` parses the input files and produces | ||
an AST that represents the input crate. | ||
|
||
- Multiple middle-end passes (`middle/resolve.rs`, `middle/typeck.rs`) | ||
analyze the semantics of the resulting AST. Each pass generates new | ||
information about the AST and stores it in various environment data | ||
structures. The driver passes environments to each compiler pass | ||
that needs to refer to them. | ||
|
||
- Finally, the `trans` module in `librustc_trans` translates the Rust | ||
AST to LLVM bitcode in a type-directed way. When it's finished | ||
synthesizing LLVM values, rustc asks LLVM to write them out in some | ||
form (`.bc`, `.o`) and possibly run the system linker. |
This file was deleted.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -1 +1 @@ | ||
See the README.txt in ../librustc. | ||
See the README.md in ../librustc. |
Oops, something went wrong.