SSA generation for basic language constructs (#3)

* Tidy code and add some documentation

* Basic data structures for risc-v backend

* Produces SSA for basic operations

* SSA for loops, branches and memory access

* Implement some of intrinsics

* Update documentation and tidy up

* Remove multiple jumps at the end of basic block

README.md

@@ -43,7 +43,7 @@ You would also need to build the core library, as instructed in the following se
 
 ### Usage
 
-MoonBit's core library is typically installed in `~/.moon/lib/core/`. In following commands, we use `$core` to denote the path. The language is shipped with pre-built libraries under different targets: `js`, `wasm` and `wasm-gc`; however, this compiler currently supports only `wasm-gc`. Let `$target` stand for this value.
+MoonBit's core library is typically installed in `~/.moon/lib/core/`. In following commands, we use `$core` to denote the path. You can choose your target between `riscv` and `wasm-gc`, which we denote by `$target`. Currently, `riscv` will only produce a `.ssa` file for static single assignment IR, and does not proceed to generate assembly.
 
 We use `$src` to denote the path to your main package. This package must contain, along with your source files, a `moon.pkg.json`; if you're not sure how this works, you can use [moon](https://github.com/moonbitlang/moon) to initialize a MoonBit repository.
 
@@ -67,15 +67,17 @@ moon bundle --source-dir $core
 
 We strongly recommend that you build the core library yourself via the commands above. The pre-built binaries are not always compatible with this compiler, as MoonBit is still under development.
 
-You should verify that there is a folder called `wasm-gc` under `$core/target`.
+You should verify that now there is a folder called `wasm-gc` under `$core/target`.
 
 Now you can compile `.mbt` files with these commands:
 
 ```bash
-bundled=$core/target/$target/release/bundle
+# Even if you are targeting RISC-V, you can still use this path.
+# That's because it's intermediate representation (IR) in the bundle;
+# it is ignorant of target.
+bundled=$core/target/wasm-gc/release/bundle
 
 # Here, main.mbt should be a file containing `fn main`.
-# `build-package` produces intermediate representation (IR); it is ignorant of target.
 moonc build-package $src/main.mbt -is-main -std-path $bundled -o $obj
 
 # If you have more than one package, remember to include all of them in -pkg-sources. They should be separated by colon ':'.

README.zh.md

@@ -41,7 +41,7 @@ dune build -p moonbit-lang
 
 ### 使用
 
-MoonBit 的核心库一般安装在 `~/.moon/lib/core` 下。在下面的命令中，我们会用 `$core` 表示核心库的安装路径。在 `$core/target` 下，有 `js`, `wasm` 和 `wasm-gc` 这三个文件夹，它们包含在对应目标下编译好的核心库。我们用 `$target` 表示这三者之一。
+MoonBit 的核心库一般安装在 `~/.moon/lib/core` 下。在下面的命令中，我们会用 `$core` 表示核心库的安装路径。你可以选择 `riscv` 或 `wasm-gc` 作为编译目标，我们用 `$target` 表示这两者之一。值得注意的是，目前 `riscv` 只会产生 SSA 文件，而不会产生汇编代码。
 
 `$src` 表示源代码的路径；在这个文件夹下，除了源代码之外还必须包括一个 `moon.pkg.json`。如果你不清楚如何编写这个文件，可以考虑使用 [moon](https://github.com/moonbitlang/moon) 来初始化。
 
@@ -70,7 +70,9 @@ moon bundle --source-dir $core
 现在你可以使用这些命令来编译 `.mbt` 文件:
 
 ```bash
-bundled=$core/target/$target/release/bundle
+# 即使 $target 是 `riscv`，也依然可以使用这个路径。
+# 这是因为 bundle 文件夹的内容是中间表示 (IR)，它和编译目标无关。
+bundled=$core/target/wasm-gc/release/bundle
 
 # 这里 main.mbt 是一个含有 `fn main` 的文件。
 moonc build-package $src/main.mbt -is-main -std-path $core/target/$bundled -o $obj -target $target

src/ast_derive.ml

@@ -1329,7 +1329,7 @@ let derive_from_json (trait : Syntax.type_name) (decl : Syntax.type_decl)
                 in
                 (S.pmap pattern, expr))
           in
-          Lst.append_one map_cases err_case |> S.match_ json
+          List.append map_cases [err_case] |> S.match_ json
       | Ptd_record fields ->
           let vars = Lst.map fields (fun _ -> fresh_name "field") in
           let pattern =

src/basic_config.ml

@@ -15,15 +15,17 @@
 
 module Map_string = Basic_map_string
 
-type target = Wasm_gc
+type target = Wasm_gc | Riscv
 
 include struct
   let sexp_of_target target = match target with
   | Wasm_gc -> S.Atom "Wasm_gc"
+  | Riscv -> S.Atom "Riscv"
 
   let hash_fold_target hsv arg =
     Ppx_base.hash_fold_int hsv (match arg with
-    | Wasm_gc -> 1)
+    | Wasm_gc -> 1
+    | Riscv -> 2)
 
   let hash_target arg =
       Ppx_base.get_hash_value
@@ -37,6 +39,7 @@ type error_format = Human | Json
 
 let parse_target_exn = function
   | "wasm-gc" -> Wasm_gc
+  | "riscv" -> Riscv
   | other -> raise (Arg.Bad ("unsupported target: " ^ other))
 
 let parse_error_format_exn = function

src/basic_core_ident.ml

@@ -28,34 +28,22 @@ module Key = struct
   include struct
     let _ = fun (_ : t) -> ()
 
-    let (hash_fold_t : Ppx_base.state -> t -> Ppx_base.state) =
-      (fun hsv arg ->
-         match arg with
-         | Pdot _a0 ->
-             let hsv = Ppx_base.hash_fold_int hsv 0 in
-             let hsv = hsv in
-             Qual_ident.hash_fold_t hsv _a0
-         | Plocal_method _a0 ->
-             let hsv = Ppx_base.hash_fold_int hsv 1 in
-             let hsv = hsv in
-             Ident.hash_fold_local_method hsv _a0
-         | Pident _ir ->
-             let hsv = Ppx_base.hash_fold_int hsv 2 in
-             let hsv =
-               let hsv = hsv in
-               Ppx_base.hash_fold_int hsv _ir.stamp
-             in
-             hsv
-         | Pmutable_ident _ir ->
-             let hsv = Ppx_base.hash_fold_int hsv 3 in
-             let hsv =
-               let hsv = hsv in
-               Ppx_base.hash_fold_int hsv _ir.stamp
-             in
-             hsv
-        : Ppx_base.state -> t -> Ppx_base.state)
-
-    let _ = hash_fold_t
+    let hash_fold_t hsv arg =
+      match arg with
+      | Pdot _a0 ->
+          let hsv = Ppx_base.hash_fold_int hsv 0 in
+          Qual_ident.hash_fold_t hsv _a0
+      | Plocal_method _a0 ->
+          let hsv = Ppx_base.hash_fold_int hsv 1 in
+          Ident.hash_fold_local_method hsv _a0
+      | Pident _ir ->
+          let hsv = Ppx_base.hash_fold_int hsv 2 in
+          let hsv = Ppx_base.hash_fold_int hsv _ir.stamp in
+          hsv
+      | Pmutable_ident _ir ->
+          let hsv = Ppx_base.hash_fold_int hsv 3 in
+          let hsv = Ppx_base.hash_fold_int hsv _ir.stamp in
+          hsv
 
     let (hash : t -> Ppx_base.hash_value) =
       let func arg =
@@ -65,52 +53,40 @@ module Key = struct
       in
       fun x -> func x
 
-    let _ = hash
-
-    let equal =
-      (fun a__001_ b__002_ ->
-         if Stdlib.( == ) a__001_ b__002_ then true
-         else
-           match (a__001_, b__002_) with
-           | Pdot _a__003_, Pdot _b__004_ -> Qual_ident.equal _a__003_ _b__004_
-           | Pdot _, _ -> false
-           | _, Pdot _ -> false
-           | Plocal_method _a__005_, Plocal_method _b__006_ ->
-               Ident.equal_local_method _a__005_ _b__006_
-           | Plocal_method _, _ -> false
-           | _, Plocal_method _ -> false
-           | Pident _a__007_, Pident _b__008_ ->
-               Stdlib.( = ) (_a__007_.stamp : int) _b__008_.stamp
-           | Pident _, _ -> false
-           | _, Pident _ -> false
-           | Pmutable_ident _a__009_, Pmutable_ident _b__010_ ->
-               Stdlib.( = ) (_a__009_.stamp : int) _b__010_.stamp
-        : t -> t -> bool)
-
-    let _ = equal
-
-    let compare =
-      (fun a__011_ b__012_ ->
-         if Stdlib.( == ) a__011_ b__012_ then 0
-         else
-           match (a__011_, b__012_) with
-           | Pdot _a__013_, Pdot _b__014_ ->
-               Qual_ident.compare _a__013_ _b__014_
-           | Pdot _, _ -> -1
-           | _, Pdot _ -> 1
-           | Plocal_method _a__015_, Plocal_method _b__016_ ->
-               Ident.compare_local_method _a__015_ _b__016_
-           | Plocal_method _, _ -> -1
-           | _, Plocal_method _ -> 1
-           | Pident _a__017_, Pident _b__018_ ->
-               Stdlib.compare (_a__017_.stamp : int) _b__018_.stamp
-           | Pident _, _ -> -1
-           | _, Pident _ -> 1
-           | Pmutable_ident _a__019_, Pmutable_ident _b__020_ ->
-               Stdlib.compare (_a__019_.stamp : int) _b__020_.stamp
-        : t -> t -> int)
-
-    let _ = compare
+    let equal a b =
+      if a == b then true
+      else match (a, b) with
+      | Pdot x, Pdot y -> Qual_ident.equal x y
+      | Pdot _, _ -> false
+      | _, Pdot _ -> false
+      | Plocal_method x, Plocal_method y ->
+          Ident.equal_local_method x y
+      | Plocal_method _, _ -> false
+      | _, Plocal_method _ -> false
+      | Pident x, Pident y ->
+          x.stamp = y.stamp
+      | Pident _, _ -> false
+      | _, Pident _ -> false
+      | Pmutable_ident x, Pmutable_ident y ->
+          x.stamp = y.stamp
+
+    let compare a b =
+      if a == b then 0
+      else match (a, b) with
+      | Pdot x, Pdot y ->
+          Qual_ident.compare x y
+      | Pdot _, _ -> -1
+      | _, Pdot _ -> 1
+      | Plocal_method x, Plocal_method y ->
+          Ident.compare_local_method x y
+      | Plocal_method _, _ -> -1
+      | _, Plocal_method _ -> 1
+      | Pident x, Pident y ->
+          Stdlib.compare x.stamp y.stamp
+      | Pident _, _ -> -1
+      | _, Pident _ -> 1
+      | Pmutable_ident x, Pmutable_ident y ->
+          Stdlib.compare x.stamp y.stamp
   end
 
   let to_string (x : t) =