From cea9e31bdd849eb0c17611bb99e33d590e126164 Mon Sep 17 00:00:00 2001
From: amesgen <amesgen@amesgen.de>
Date: Mon, 3 Apr 2023 13:34:42 +0200
Subject: [PATCH] Add WASI initialization support

---
 .github/workflows/simple.yml | 26 ++++++++++++++++++++++++++
 cbits-wasi/init.c            |  8 ++++++++
 splitmix.cabal               | 10 ++++++++--
 3 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 cbits-wasi/init.c

diff --git a/.github/workflows/simple.yml b/.github/workflows/simple.yml
index 8865f90..3c02c2b 100644
--- a/.github/workflows/simple.yml
+++ b/.github/workflows/simple.yml
@@ -44,3 +44,29 @@ jobs:
 
       - name: Test
         run: cabal test all --enable-tests --test-show-details=direct
+  wasi:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ghc: ['9.6', '9.8', '9.10', '9.12']
+      fail-fast: false
+    steps:
+    - name: setup-ghc-wasm32-wasi
+      run: |
+        cd $(mktemp -d)
+        curl -L https://gitlab.haskell.org/haskell-wasm/ghc-wasm-meta/-/archive/$GHC_WASM_META_REV/ghc-wasm-meta.tar.gz | tar xz --strip-components=1
+        ./setup.sh
+        ~/.ghc-wasm/add_to_github_path.sh
+      env:
+        GHC_WASM_META_REV: f0faac335c6f5e967d1bdbfca5768232483fd2a8
+        FLAVOUR: ${{ matrix.ghc }}
+    - uses: actions/checkout@v4
+    - name: Build
+      run: |
+        wasm32-wasi-cabal build splitmix splitmix:test:examples splitmix:test:initialization
+    - name: Test
+      run: |
+        for test in examples initialization; do
+          echo --- Running test $test ---
+          wasmtime $(wasm32-wasi-cabal list-bin splitmix:test:$test)
+        done
diff --git a/cbits-wasi/init.c b/cbits-wasi/init.c
new file mode 100644
index 0000000..2b9b017
--- /dev/null
+++ b/cbits-wasi/init.c
@@ -0,0 +1,8 @@
+#include <stdint.h>
+#include <sys/random.h>
+
+uint64_t splitmix_init() {
+  uint64_t result;
+  int r = getentropy(&result, sizeof(uint64_t));
+  return r == 0 ? result : 0xfeed1000;
+}
diff --git a/splitmix.cabal b/splitmix.cabal
index fc1cb14..c66d12e 100644
--- a/splitmix.cabal
+++ b/splitmix.cabal
@@ -93,7 +93,11 @@ library
         c-sources: cbits-win/init.c
 
       else
-        c-sources: cbits-unix/init.c
+        if arch(wasm32)
+          c-sources: cbits-wasi/init.c
+
+        else
+          c-sources: cbits-unix/init.c
 
     else
       cpp-options:   -DSPLITMIX_INIT_COMPAT=1
@@ -226,7 +230,9 @@ test-suite splitmix-testu01
 test-suite initialization
   default-language: Haskell2010
   type:             exitcode-stdio-1.0
-  ghc-options:      -Wall -threaded -rtsopts
+  ghc-options:      -Wall -rtsopts
+  if !arch(wasm32)
+    ghc-options:    -threaded
   hs-source-dirs:   tests
   main-is:          Initialization.hs
   build-depends: