WASI runtime

.github/workflows/js_of_ocaml.yml

@@ -24,7 +24,6 @@ jobs:
         ocaml-name:
           - ""
         ocaml-compiler:
-          - "4.13"
           - "5.0"
           - "5.1"
           - "5.2"

.github/workflows/lint.yml

@@ -26,6 +26,7 @@ jobs:
         with:
           token: ${{ github.token }}
       - run: sh tools/make_opam_dune_lint_dir.sh
+      - run: opam pin -n opam-dune-lint --dev-repo
       - uses: ocaml/setup-ocaml/lint-opam@v3
 
   lint-fmt:

.github/workflows/wasm_of_ocaml.yml

@@ -34,13 +34,16 @@ jobs:
           - false
         all_jane_street_tests:
           - false
+        wasi:
+          - false
         include:
           - os: macos-latest
             os-name: MacOS
             ocaml-compiler: "5.3"
             separate_compilation: true
             jane_street_tests: false
             all_jane_street_tests: false
+            wasi: false
           - os: windows-latest
             os-name: Windows
             ocaml-compiler: "5.3"
@@ -54,23 +57,33 @@ jobs:
             separate_compilation: true
             jane_street_tests: true
             all_jane_street_tests: true
+            wasi: false
           - os: ubuntu-latest
             os-name: Ubuntu
             ocaml-compiler: "5.3"
             separate_compilation: false
             jane_street_tests: true
             all_jane_street_tests: false
+            wasi: false
           - os: ubuntu-latest
             os-name: Ubuntu
             ocaml-compiler: "ocaml-variants.5.2.0+ox"
             separate_compilation: true
             jane_street_tests: true
             all_jane_street_tests: true
+            wasi: false
+          - os: ubuntu-latest
+            os-name: Ubuntu
+            ocaml-compiler: "5.3"
+            separate_compilation: true
+            jane_street_tests: false
+            all_jane_street_tests: false
+            wasi: true
 
     runs-on: ${{ matrix.os }}
 
     name:
-       ${{ (! matrix.separate_compilation) && 'Whole program / ' || ''}}${{ matrix.ocaml-compiler }} / ${{ matrix.os-name }}${{ matrix.all_jane_street_tests && ' / Jane Street tests' || ''}}
+       ${{ matrix.wasi && 'WASI / ' || '' }}${{ (! matrix.separate_compilation) && 'Whole program / ' || ''}}${{ matrix.ocaml-compiler }} / ${{ matrix.os-name }}${{ matrix.all_jane_street_tests && ' / Jane Street tests' || ''}}
 
     steps:
       - name: Update apt cache
@@ -101,7 +114,55 @@ jobs:
       - name: Set-up Node.js
         uses: actions/setup-node@v6
         with:
-          node-version: latest
+          node-version: ${{ matrix.os == 'windows-latest' && 'latest' || 'v26.0.0-v8-canary20260216631fb6e5ef' }}
+
+      - name: Set-up Rust toolchain
+        if: matrix.wasi
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+
+      - name: Checkout Wasmtime
+        if: matrix.wasi
+        uses: actions/checkout@v4
+        with:
+          repository: bytecodealliance/wasmtime
+          path: wasmtime
+          submodules: true
+
+      - name: Build Wasmtime
+        if: matrix.wasi
+        working-directory: ./wasmtime
+        run: |
+          cargo build
+          echo `pwd`/target/debug >> "$GITHUB_PATH"
+
+      - name: Checkout Virgil
+        if: matrix.wasi
+        uses: actions/checkout@v4
+        with:
+          repository: titzer/virgil
+          path: virgil
+
+      - name: Build Virgil
+        if: matrix.wasi
+        working-directory: ./virgil
+        run: |
+          export PATH=$PATH:`pwd`/bin
+          echo `pwd`/bin >> "$GITHUB_PATH"
+          make
+
+      - name: Checkout Wizard engine
+        if: matrix.wasi
+        uses: actions/checkout@v4
+        with:
+          repository: titzer/wizard-engine
+          path: wizard-engine
+
+      - name: Build Wizard engine
+        if: matrix.wasi
+        working-directory: ./wizard-engine
+        run: |
+          make -j 4
+          echo `pwd`/bin >> "$GITHUB_PATH"
 
       - name: Set-up OCaml ${{ matrix.ocaml-compiler }}
         uses: ocaml/setup-ocaml@v3
@@ -169,7 +230,7 @@ jobs:
           opam install . -t
 
       - name: Run tests
-        if: ${{ matrix.separate_compilation }}
+        if: ${{ matrix.separate_compilation && ! matrix.wasi }}
         working-directory: ./wasm_of_ocaml
         run: opam exec -- dune build @runtest-wasm
 
@@ -178,11 +239,36 @@ jobs:
       # See https://github.com/libuv/libuv/issues/3622
 
       - name: Run tests with CPS effects
-        if: ${{ matrix.ocaml-compiler >= '5.' && matrix.separate_compilation }}
+        if: ${{ matrix.ocaml-compiler >= '5.' && matrix.separate_compilation && ! matrix.wasi }}
         continue-on-error: ${{ matrix.os == 'windows-latest' }}
         working-directory: ./wasm_of_ocaml
         run: opam exec -- dune build @runtest-wasm --profile with-effects
 
+      - name: Run tests with native effects
+        if: ${{ matrix.ocaml-compiler >= '5.' && matrix.separate_compilation && matrix.os != 'windows-latest' }}
+        working-directory: ./wasm_of_ocaml
+        run: opam exec -- dune build @runtest-wasm --profile with-native-effects
+
+      - name: Run tests (WASI runtime - node)
+        if: ${{ matrix.wasi }}
+        working-directory: ./wasm_of_ocaml
+        run: opam exec -- dune build @runtest-wasm --profile wasi
+
+      - name: Run tests (WASI runtime - Wizard engine)
+        if: ${{ matrix.wasi }}
+        working-directory: ./wasm_of_ocaml
+        env:
+          WASM_ENGINE: wizard-fast
+        run: opam exec -- dune build @runtest-wasm --profile wasi
+
+      - name: Run tests (WASI runtime - wasmtime)
+        if: ${{ matrix.wasi }}
+        working-directory: ./wasm_of_ocaml
+        env:
+          WASM_ENGINE: wasmtime
+          WASI_FLAGS: --enable exnref
+        run: opam exec -- dune build @runtest-wasm --profile wasi
+
       - name: Run Base tests
         if: matrix.all_jane_street_tests
         continue-on-error: ${{ matrix.os == 'windows-latest' }}

CHANGES.md

@@ -10,6 +10,8 @@
 * Compiler: improved shape computation (#2198)
 * Add the --build-config and --apply-build-config flags (#2177)
 * Runtime/wasm: optimized some bigstring primitives (#2144)
+* Wasm_of_ocaml: alternative effect implementation based on the Stack Switching proposal (#2189)
+* Compiler/wasm: WASI 0.1 support (#1831)
 
 ## Bug fixes
 * Compiler: fix reference unboxing (#2210)

CLAUDE.md

@@ -80,7 +80,7 @@ opam install odoc lwt_log yojson ocp-indent graphics higlo
 ```
 
 **Requirements:**
-- OCaml 4.13 to 5.4
+- OCaml 4.14 to 5.4
 - Dune 3.19+
 - For wasm_of_ocaml: Binaryen 119+
 

VERSION

@@ -1 +1 @@
-6.3.2
+6.4.0~alpha~dev

compiler/bin-wasm_of_ocaml/cmd_arg.ml

@@ -38,16 +38,18 @@ let trim_trailing_dir_sep s =
 
 let normalize_include_dirs dirs = List.map dirs ~f:trim_trailing_dir_sep
 
-let normalize_effects (effects : [ `Disabled | `Cps | `Jspi ] option) common :
+let normalize_effects (effects : [ `Disabled | `Cps | `Jspi | `Native ] option) common :
     Config.effects_backend =
   match effects with
   | None ->
       (* For backward compatibility, consider that [--enable effects] alone means
         [--effects cps] *)
       if List.mem ~eq:String.equal "effects" common.Jsoo_cmdline.Arg.optim.enable
       then `Cps
+      else if List.mem ~eq:String.equal "wasi" common.Jsoo_cmdline.Arg.optim.enable
+      then `Disabled
       else `Jspi
-  | Some ((`Disabled | `Cps | `Jspi) as e) -> e
+  | Some ((`Disabled | `Cps | `Jspi | `Native) as e) -> e
 
 type t =
   { common : Jsoo_cmdline.Arg.t
@@ -182,11 +184,15 @@ let options () =
   let effects =
     let doc =
       "Select an implementation of effect handlers. [$(docv)] should be one of $(b,jspi) \
-       (the default), $(b,cps), or $(b,disabled)."
+       (the default), $(b,cps), $(b,native) or $(b,disabled)."
     in
     Arg.(
       value
-      & opt (some (enum [ "jspi", `Jspi; "cps", `Cps; "disabled", `Disabled ])) None
+      & opt
+          (some
+             (enum
+                [ "jspi", `Jspi; "cps", `Cps; "native", `Native; "disabled", `Disabled ]))
+          None
       & info [ "effects" ] ~docv:"KIND" ~doc)
   in
   let build_t
@@ -330,11 +336,15 @@ let options_runtime_only () =
   let effects =
     let doc =
       "Select an implementation of effect handlers. [$(docv)] should be one of $(b,jspi) \
-       (the default), $(b,cps), or $(b,disabled)."
+       (the default), $(b,cps), $(b,native) or $(b,disabled)."
     in
     Arg.(
       value
-      & opt (some (enum [ "jspi", `Jspi; "cps", `Cps; "disabled", `Disabled ])) None
+      & opt
+          (some
+             (enum
+                [ "jspi", `Jspi; "cps", `Cps; "native", `Native; "disabled", `Disabled ]))
+          None
       & info [ "effects" ] ~docv:"KIND" ~doc)
   in
   let build_config = Jsoo_cmdline.Arg.build_config in

compiler/bin-wasm_of_ocaml/compile.ml

@@ -81,9 +81,13 @@ let preprocessor_variables () =
   [ ( "effects"
     , Wat_preprocess.String
         (match Config.effects () with
-        | `Disabled | `Jspi -> "jspi"
+        | `Disabled -> "disabled"
+        | `Jspi -> "jspi"
         | `Cps -> "cps"
+        | `Native -> "native"
         | `Double_translation -> assert false) )
+  ; "wasi", Wat_preprocess.Bool (Config.Flag.wasi ())
+  ; "exnref", Wat_preprocess.Bool (Config.Flag.exnref ())
   ]
 
 let with_runtime_files ~runtime_wasm_files f =
@@ -115,21 +119,26 @@ let build_runtime ~runtime_file =
             ; file = module_name ^ ".wat"
             ; source = Contents contents
             })
-          Runtime_files.wat_files
+          (if Config.Flag.wasi ()
+           then ("libc", Runtime_files.wasi_libc) :: Runtime_files.wat_files
+           else Runtime_files.wat_files)
       in
       Runtime.build
         ~link_options:[ "-g" ]
         ~opt_options:[ "-g"; "-O2" ]
         ~variables
         ~allowed_imports:
           (Some
-             [ "bindings"
-             ; "Math"
-             ; "js"
-             ; "wasm:js-string"
-             ; "wasm:text-encoder"
-             ; "wasm:text-decoder"
-             ])
+             (if Config.Flag.wasi ()
+              then [ "wasi_snapshot_preview1"; "OCaml" ]
+              else
+                [ "bindings"
+                ; "Math"
+                ; "js"
+                ; "wasm:js-string"
+                ; "wasm:text-encoder"
+                ; "wasm:text-decoder"
+                ]))
         ~inputs
         ~output_file:runtime_file
 
@@ -210,7 +219,10 @@ let link_and_optimize
     let t = Timer.make ~get_time:Unix.time () in
     let primitives =
       Binaryen.dead_code_elimination
-        ~dependencies:Runtime_files.dependencies
+        ~dependencies:
+          (if Config.Flag.wasi ()
+           then Runtime_files.wasi_dependencies
+           else Runtime_files.dependencies)
         ~opt_input_sourcemap:opt_temp_sourcemap
         ~opt_output_sourcemap:opt_temp_sourcemap'
         ~input_file:temp_file
@@ -318,7 +330,14 @@ let build_js_runtime ~primitives ?runtime_arguments () =
     | _ -> assert false
   in
   let init_fun =
-    match Parse_js.parse `Script (Parse_js.Lexer.of_string Runtime_files.js_runtime) with
+    match
+      Parse_js.parse
+        `Script
+        (Parse_js.Lexer.of_string
+           (if Config.Flag.wasi ()
+            then Runtime_files.js_wasi_launcher
+            else Runtime_files.js_launcher))
+    with
     | [ (Expression_statement f, _) ] -> f
     | _ -> assert false
   in
@@ -682,9 +701,12 @@ let run
          if binaryen_times ()
          then Format.eprintf " link_and_optimize: %a@." Timer.print t2;
          let wasm_name =
-           Printf.sprintf
-             "code-%s"
-             (String.sub (Digest.to_hex (Digest.file tmp_wasm_file)) ~pos:0 ~len:20)
+           if Config.Flag.wasi ()
+           then "code"
+           else
+             Printf.sprintf
+               "code-%s"
+               (String.sub (Digest.to_hex (Digest.file tmp_wasm_file)) ~pos:0 ~len:20)
          in
          let tmp_wasm_file' = Filename.concat tmp_dir (wasm_name ^ ".wasm") in
          Sys.rename tmp_wasm_file tmp_wasm_file';

compiler/bin-wasm_of_ocaml/dune

@@ -28,6 +28,9 @@
   gen/gen.exe
   ../../runtime/wasm/runtime.js
   ../../runtime/wasm/deps.json
+  ../../runtime/wasm/runtime-wasi.js
+  ../../runtime/wasm/deps-wasi.json
+  ../../runtime/wasm/libc.wasm
   (glob_files ../../runtime/wasm/*.wat)
   (glob_files ../../runtime/wasm/runtime-*.wasm))
  (action