This is a request to remove the Chinese portions from the ViperC README. Here is the resulting document with all Chinese sections stripped, keeping only the English content.

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# ViperC

The **Viper language compiler, written in Viper itself** — and it is **self-hosted**: ViperC compiles its own source and produces `viperc.exe`. It translates Viper sources to LLVM IR, then drives `llc` + `clang++` to link a native Windows executable. The first-generation CPython compiler ([TransPyC](https://git.gvsds.com/GVSDS/TransPyC)) is now only kept as the bootstrapping **seed**.

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<a id="english"></a>

## English

### What is this

`ViperC` is the second-generation Viper compiler: **written in Viper and compiled by Viper**. No Python runtime takes part in the compilation path — lexing/parsing goes through `includes/ast` (a self-implemented parser, 9 files), IR generation through `App/lib/core/Gen/`, and machine code through `llc` + `clang++`.

The bootstrap chain:

```text
TransPyC (seed, implemented in CPython)
    │  one-time only: compile ViperC sources into viperc.exe
    ▼
viperc.exe (stage-one artifact)
    │  bootstrap: this exe compiles ViperC itself
    ▼
viperc.exe (self-hosted artifact — the one shipped in exe\)
    │
    └─ used to build any Viper project (ViperApps\*, Test\* …)
```

Current state and size (measured on the dev machine):

| Item | Value |
| --- | --- |
| Compiler sources | **82 `.vp` files, 63,783 lines** under `App/` |
| Translator core | `App/lib/core/Gen/` — **54 files, 47,297 lines** |
| Phases & merging | `App/lib/Phase/` 6 files 5,339 lines; `App/lib/Stub/` 9 files 6,207 lines |
| Project & utils | `App/lib/Projectrans/` 3 files 712 lines |
| Self-tests | workspace root `Test\` (**separate repo**): **97 projects, 129 `.vp`**, driven by `Test\SequentialRegressionTest.py` |
| Platform | Windows x64 (sources `import win32.*` directly) |

### Directory layout

```text
ViperC/
├── project.vpj                 # project config (source_dir=./App, build_dir=./__vpcbuild__, output viperc.exe)
├── App/                        # compiler sources (Viper)
│   ├── main.vp                 # CLI entry: pools, singleton injection, arg parsing, phase dispatch
│   └── lib/
│       ├── Projectrans/
│       │   ├── Config.vp        # project.vpj loader + path resolution (incl. includes cache dir)
│       │   └── Utils.vp         # SHA1 / dir cleanup / misc
│       ├── core/
│       │   ├── VLogger.vp       # logging (info/warn/error/banner/success)
│       │   ├── IncludesScanner.vp   # scan includes/, decide what must be rebuilt
│       │   ├── CompilerFactory.vp   # holds the two MemBuddy singletons (mb + perm_pool)
│       │   └── Gen/             # translator (52 files) — AST to LLVM IR
│       │       ├── Generator.vp / Translator.vp / GenApi.vp / GenTypes.vp
│       │       ├── BaseGenMixin / AssignGenMixin / VarGenMixin / ImportsGenMixin
│       │       ├── MatchGenMixin / AsyncGenMixin / StructGenMixin / TranslatorGenMixin
│       │       ├── Call/   (12) calls: plain / C builtin / ctor / vtable / varargs / inline asm …
│       │       ├── Class/  (6)  classes: def / generic / vtable / enum / mixin
│       │       ├── Expr/   (9)  expressions: name / const / ops / attr / f-string / CDef …
│       │       ├── Func/   (3)  function definitions
│       │       ├── Stmt/   (3)  statements: decl / C-if / mixin
│       │       └── Type/   (6)  type resolution and C type mapping
│       ├── Phase/
│       │   ├── BuildPipeline.vp # .ll -> llc -> .obj -> clang++ -> .exe (plus ASan branch)
│       │   ├── Phase1/          # Phase 1: on-demand includes translation + stub split (.stub.ll / .text.ll)
│       │   └── Phase2/          # Phase 2: multi-file translation, IR assembly, compile
│       └── Stub/
│           ├── StubGen/         # .vpi reader + declaration converter
│           └── StubMerger/      # dependency-ordered merge of .stub.ll / .text.ll
```

> The self-test/regression suite is not in this repo: it lives at the workspace root `Test\`
> (a separate repo, 97 projects, 129 `.vp`), driven by `Test\SequentialRegressionTest.py`
> (`--exe exe\viperc.exe`).

### Prerequisites

| Tool | Notes |
| --- | --- |
| Windows 10/11 x64 | sources `import win32.*`; Windows-only for now |
| `llc` | LLVM static compiler (22.1.8 here), set by `compiler.cmd` in `project.vpj` |
| `clang++` | mingw-w64 toolchain, `-fuse-ld=lld` (here `D:/msys64/mingw64/bin/clang++.exe`) |
| ≥ 1.5 GiB free RAM | allocates a 1 GiB main pool + 512 MiB permanent pool at startup |
| [TransPyC](https://git.gvsds.com/GVSDS/TransPyC) | **only needed to rebuild the bootstrap seed** |

Required layout (`project.vpj` refers to `../includes`):

```text
TransPyC\                 # workspace root
├── TransPyC\             # first-generation compiler (seed)
├── ViperC\               # this repo
├── Test\                 # regression suite (separate repo)
├── exe\                  # shipped self-hosted artifact (viperc.exe)
└── includes\             # Viper standard library + includes/ast parser
```

### Quick start

```bat
:: everyday use: build any project with the self-hosted compiler
exe\viperc.exe --project ViperApps\ViperMNIST\project.vpj --clean

:: build and run immediately
exe\viperc.exe --project ViperApps\ViperMNIST\project.vpj --clean --run

:: only when rebuilding the compiler itself (bootstrap seed), use TransPyC
python TransPyC\Projectrans.py --project ViperC\project.vpj --clean
```

Artifacts land in `<project dir>\<build_dir>\output\<linker.output>` — by default
`<project>\__vpcbuild__\output\app.exe`. ViperC itself sets `linker.output` to `viperc.exe`,
so its own product is `ViperC\__vpcbuild__\output\viperc.exe`.

Run the regression suite (workspace root `Test\`, a separate repo):

```bat
python Test\SequentialRegressionTest.py --exe exe\viperc.exe
```

### CLI flags

| Flag | Meaning |
| --- | --- |
| `--project <path>` | `project.vpj` path (default: current dir, then parent) |
| `--src <dir>` | single-file mode source dir (overrides config; entry `<dir>/main.vp`) |
| `--temp <dir>` | declaration temp dir (default `<build_dir>/temp`) |
| `--output <dir>` | output dir (default `<build_dir>/output`) |
| `--phase 1\|2\|all` | 1 = stub split only; 2 = IR assembly + compile only; all = both (default) |
| `--cc <cmd>` | LLVM compiler command (overrides config) |
| `--build-dir <dir>` | override `build_dir` from `project.vpj` (relative paths still resolve against the project dir) |
| `--clean` | clean temp / output / includes precompiled cache |
| `--rebuild-includes` | delete only the includes cache (`includes.binary`), forcing a full includes rebuild |
| `--clear-cache` | clear only temp (`.vpi` / `.stub.ll` / `.text.ll`), forcing stub regeneration |
| `--run` | execute the produced binary on success |
| `--repl` | interactive REPL (M1: expression fragment → DLL → call and echo); without `--project` it looks for the `repl.vpj` template project in cwd, then next to `viperc.exe` (errors out with a `--project` hint if neither exists); mutually exclusive with `--asan` / `--phase2command` |
| `--asan` | ASan mode: `opt -passes=asan` first; runtimes must be declared in `project.vpj` `linker.static_libs`, else fail-fast |
| `--phase2command <bat>` | do not run `llc`/link; write the commands into the given `.bat` |
| `--nowarn-register` | suppress Phase A dependency WARNs (cross-module `text.ll` not yet emitted, converges next pass) |
| `--no-llvmpeephole` | disable FunctionPrint local peepholes (T2 store/load forwarding, T3 no-op bitcast) |
| `--detection` | enable MemBuddy allocation detection (`0xCDCD` fill + record-table probe for out-of-bounds writes) |
| `--show-args` | dump all parsed arguments |
| `--version`, `-v` | print Viper / VRTE / ViperC versions, commit ids, target triple and LLVM version |
| `--help`, `-h` | print help |

### Architecture

```text
all .vp/.py under source_dir (multi-file mode: recursively scanned)
    │
    ├─ Phase 1 (stub split)
    │     IncludesScanner translates includes on demand -> Phase1/*
    │     Translator + Gen/* emit IR, then write two files:
    │       <sha1>.stub.ll   declarations
    │       <sha1>.text.ll   implementations
    │
    ├─ Phase 2 (assemble + compile)
    │     StubMerger*  topologically merge local stub + dependency stubs + local text -> full IR
    │     BuildPipeline: full IR -> llc -> .obj -> clang++ (+ precompiled includes .obj) -> .exe
    │
    └─ <build_dir>/output/<linker.output>
```

**Module responsibilities:**

| Module | Responsibility |
| --- | --- |
| `App/main.vp` | CLI entry: pools and singletons, arg parsing, phase dispatch, `--run` |
| `lib/Projectrans/Config.vp` | `project.vpj` loading, path resolution, includes cache dir |
| `lib/core/CompilerFactory.vp` | owns `mb` (main pool) and `perm_pool` (permanent pool) |
| `lib/core/Gen/Generator.vp` | project-level `Generator` singleton shared by Phase1/Phase2/BuildPipeline |
| `lib/core/Gen/Translator.vp` | translator body: `translate()` and `dump_ir()` (`.stub.ll` / `.text.ll` / full IR) |
| `lib/core/Gen/GenApi.vp` | translator public API and global state (e.g. temp dir) |
| `lib/Phase/Phase1/` | scan includes, topological order, emit declarations on demand |
| `lib/Phase/Phase2/` | multi-file projects: scan sources, translate, assemble IR, drive the build |
| `lib/Phase/BuildPipeline.vp` | `.ll` -> `llc` -> `.obj` -> `clang++` -> `.exe` (ASan branch included) |
| `lib/Stub/StubGen/` | read `.vpi`, convert to stub declarations |
| `lib/Stub/StubMerger/` | collect / topologically sort / concatenate / store `stub.ll` and `text.ll` |
| `lib/core/IncludesScanner.vp` | scan `includes/`, decide what needs rebuilding |
| `lib/core/VLogger.vp` | logging (with the `--nowarn-register` switch) |

> Bootstrap note: after self-hosting, module-level globals carry a **SHA1 prefix** (module
> isolation), so singletons such as `_g_gen` must be assigned **per module**
> (`GenApi._g_gen = gen` …), not once by bare name in `main.vp` — otherwise some modules read
> their own `None`, showing up as bogus results like "global-name test always 0".

### Memory model

There is no per-object system `malloc` churn — only two `MemBuddy` buddy-allocator pools:

- `POOL_SIZE = 1 GiB` (`1073741824`) — main pool `mb`, ordinary translation allocations.
- `PERM_POOL_SIZE = 536871176` (≈512 MiB usable) — permanent pool `perm_pool`, objects that outlive a phase.
- Both are held by the `CompilerFactory.factory` singleton; `mb` is additionally injected per module
  as `sys._mbuddy` / `argparse._mbuddy` / `ast._mbuddy` / `Config._mbuddy` …

`--detection` switches both pools into detection mode (`0xCDCD` fill + record-table probe) to hunt
out-of-bounds writes.

### Relation to TransPyC

| Dimension | TransPyC | ViperC |
| --- | --- | --- |
| Implementation | CPython | Viper |
| Role | bootstrap **seed** (only used to produce a stable ViperC) | **the current compiler** |
| Self-hosted? | — | ✅ yes, it compiles itself |
| Entry | `TransPyC/Projectrans.py` | `App/main.vp` |
| AST parsing | Python `ast` / in-house vast | `includes/ast` (9 files, in-house) |
| Project config | `project.json` | `project.vpj` |
| Platform | Windows / Linux | Windows (`win32.*`) |

### Further reading

- [TransPyC compiler repo (the seed)](https://git.gvsds.com/GVSDS/TransPyC)
- [Viper language docs (wiki)](https://git.gvsds.com/GVSDS/TransPyC/tree/main/wiki)
- [Bootstrapping analysis and progress](https://git.gvsds.com/GVSDS/TransPyC/blob/main/wiki/13-bootstrapping.md)
- [Compilation system (`project.vpj` / `viperbuild` metaprogramming)](https://git.gvsds.com/GVSDS/TransPyC/blob/main/wiki/12-compilation-system.md)
- [ViperOS (an OS written in Viper)](https://git.gvsds.com/GVSDS/ViperOS)