Add script for preparing the wasm libraries for building without Nix

scripts/wasm-without-nix/build-wasm-libs.sh

@@ -0,0 +1,219 @@
+#!/usr/bin/env bash
+# Build libsodium, libsecp256k1, and libblst for wasm32-wasi and install them
+# into a single prefix that cabal.project can point at via extra-lib-dirs /
+# extra-include-dirs. Mirrors ./nix/{libsodium,secp256k1,blst}.nix but uses
+# wasm32-wasi-clang directly (no Nix).
+#
+# Requirements on PATH: wasm32-wasi-clang (from wasi-sdk), autoreconf,
+# automake, libtool, make, git, pkg-config.
+
+set -euo pipefail
+
+# Script must be run from the root of the project
+PROJECT_DIR="$(pwd)"
+[ -f "$PROJECT_DIR/cabal.project" ] || {
+    echo "Error: cabal.project not found in $PROJECT_DIR. Run this script from the root of the project" >&2
+    exit 1
+}
+
+missing=()
+[ -n "${PREFIX:-}" ]   || missing+=(PREFIX)
+[ -n "${SRC_ROOT:-}" ] || missing+=(SRC_ROOT)
+if [ "${#missing[@]}" -gt 0 ]; then
+    cat >&2 <<EOF
+Error: required environment variable(s) not set: ${missing[*]}
+
+Both values are interpreted relative to the cabal.project directory
+($PROJECT_DIR) unless given as an absolute path.
+
+  PREFIX    where the wasm libs/headers will be installed, e.g. wasm-libs.
+            Will be created if missing. Point cabal.project's
+            extra-lib-dirs / extra-include-dirs at \$PREFIX/lib and
+            \$PREFIX/include.
+
+  SRC_ROOT  where the libsodium / secp256k1 / blst source trees live (or
+            will be cloned into as \$SRC_ROOT/{libsodium,secp256k1,blst}),
+            e.g. wasm-deps.
+
+Example:
+  PREFIX=wasm-libs SRC_ROOT=wasm-libs-src $0
+EOF
+    exit 1
+fi
+
+resolve_rel() {
+    case "$1" in
+        /*) printf '%s\n' "$1" ;;
+        *)  printf '%s\n' "$PROJECT_DIR/$1" ;;
+    esac
+}
+
+ABS_PREFIX="$(resolve_rel "$PREFIX")"
+ABS_SRC_ROOT="$(resolve_rel "$SRC_ROOT")"
+
+# Toolchain check: wasm32-wasi-clang must be on PATH (drives both compile and
+# link). The other wasm32-wasi-* tools come along with it via the wasi-sdk /
+# ghc-wasm env.
+toolchain_missing=()
+for t in wasm32-wasi-clang wasm-ld; do
+    command -v "$t" >/dev/null 2>&1 || toolchain_missing+=("$t")
+done
+if [ "${#toolchain_missing[@]}" -gt 0 ]; then
+    cat >&2 <<EOF
+Error: wasm toolchain not on PATH (missing: ${toolchain_missing[*]}).
+
+The ghc-wasm / wasi-sdk environment doesn't appear to be active. Activate it
+with:
+
+  source ~/.ghc-wasm/env
+
+then re-run this script.
+EOF
+    exit 1
+fi
+
+LIBSODIUM_REV="9511c982fb1d046470a8b42aa36556cdb7da15de"
+LIBSODIUM_REPO="https://github.com/jedisct1/libsodium.git"
+SECP256K1_REPO="https://github.com/bitcoin-core/secp256k1.git"
+BLST_REPO="https://github.com/supranational/blst.git"
+
+mkdir -p "$ABS_PREFIX/lib" "$ABS_PREFIX/include" "$ABS_PREFIX/lib/pkgconfig"
+
+clone_if_missing() {
+    local repo="$1" dir="$2" rev="${3:-}"
+    if [ ! -d "$dir/.git" ]; then
+        git clone "$repo" "$dir"
+    fi
+    if [ -n "$rev" ]; then
+        git -C "$dir" fetch --tags origin "$rev" 2>/dev/null || true
+        git -C "$dir" checkout "$rev"
+    fi
+}
+
+build_libsodium() {
+    local dir="$ABS_SRC_ROOT/libsodium"
+    clone_if_missing "$LIBSODIUM_REPO" "$dir" "$LIBSODIUM_REV"
+    cd "$dir"
+    [ -x ./configure ] || ./autogen.sh -s
+    ./configure --host=wasm32-wasi --prefix="$ABS_PREFIX"
+    make -j"$(nproc)"
+    make install
+    wasm32-wasi-clang -shared -Wl,--whole-archive \
+        "$ABS_PREFIX/lib/libsodium.a" \
+        -o "$ABS_PREFIX/lib/libsodium.so"
+}
+
+build_secp256k1() {
+    local dir="$ABS_SRC_ROOT/secp256k1"
+    clone_if_missing "$SECP256K1_REPO" "$dir"
+    cd "$dir"
+    [ -x ./configure ] || ./autogen.sh
+    ./configure \
+        --host=wasm32-wasi \
+        --enable-module-schnorrsig \
+        --prefix="$ABS_PREFIX" \
+        SECP_CFLAGS=-fPIC
+    make -j"$(nproc)"
+    make install
+    wasm32-wasi-clang -shared -Wl,--whole-archive \
+        "$ABS_PREFIX/lib/libsecp256k1.a" \
+        -o "$ABS_PREFIX/lib/libsecp256k1.so"
+}
+
+build_blst() {
+    local dir="$ABS_SRC_ROOT/blst"
+    clone_if_missing "$BLST_REPO" "$dir"
+    cd "$dir"
+    CC=wasm32-wasi-clang ./build.sh
+
+    cp libblst.a "$ABS_PREFIX/lib/"
+    cp bindings/blst.h bindings/blst_aux.h "$ABS_PREFIX/include/"
+
+    wasm32-wasi-clang -shared -Wl,--whole-archive \
+        "$ABS_PREFIX/lib/libblst.a" \
+        -o "$ABS_PREFIX/lib/libblst.so"
+
+    local version
+    version="$(git -C "$dir" describe --tags --always 2>/dev/null || echo 0.0.0)"
+    cat > "$ABS_PREFIX/lib/pkgconfig/libblst.pc" <<EOF
+prefix=$ABS_PREFIX
+exec_prefix=\${prefix}
+libdir=\${exec_prefix}/lib
+includedir=\${prefix}/include
+
+Name: libblst
+Description: blst BLS12-381 signature library
+URL: https://github.com/supranational/blst
+Version: $version
+
+Cflags: -I\${includedir}
+Libs: -L\${libdir} -lblst
+Libs.private:
+EOF
+}
+
+verify_wasm() {
+    local archive="$1"
+    local tmp
+    tmp="$(mktemp -d)"
+    ( cd "$tmp" && ar x "$archive" && \
+      first_obj="$(ls *.o 2>/dev/null | head -1)" && \
+      [ -n "$first_obj" ] && file "$first_obj" | grep -q WebAssembly )
+    local rc=$?
+    rm -rf "$tmp"
+    if [ "$rc" -ne 0 ]; then
+        echo "ERROR: $archive does not appear to contain wasm objects" >&2
+        exit 1
+    fi
+}
+
+build_libsodium 2>&1 | sed -u $'s/^/\033[1;32mlibsodium\033[0m > /'
+build_secp256k1 2>&1 | sed -u $'s/^/\033[1;36msecp256k1\033[0m > /'
+build_blst      2>&1 | sed -u $'s/^/\033[1;33mblst\033[0m      > /'
+
+verify_wasm "$ABS_PREFIX/lib/libsodium.a"
+verify_wasm "$ABS_PREFIX/lib/libsecp256k1.a"
+verify_wasm "$ABS_PREFIX/lib/libblst.a"
+
+echo
+echo "Done. Installed to: $ABS_PREFIX"
+
+FRAGMENT="$PROJECT_DIR/wasm-libs-without-nix.cabal"
+cat > "$FRAGMENT" <<EOF
+shared: True
+
+package cardano-crypto-class
+  extra-lib-dirs: $ABS_PREFIX/lib
+  extra-include-dirs: $ABS_PREFIX/include
+
+package cardano-crypto-praos
+  extra-lib-dirs: $ABS_PREFIX/lib
+  extra-include-dirs: $ABS_PREFIX/include
+EOF
+echo "Wrote project fragment: $FRAGMENT"
+
+CABAL_PROJECT="$PROJECT_DIR/cabal.project"
+
+if grep -qF "wasm-libs-without-nix.cabal" "$CABAL_PROJECT"; then
+    echo "cabal.project already imports wasm-libs-without-nix.cabal — nothing to do."
+else
+    read -r -p "Add 'if arch(wasm32) / import: wasm-libs-without-nix.cabal' block to cabal.project? [y/N] " answer || answer=""
+    case "${answer,,}" in
+        y|yes)
+            cat >> "$CABAL_PROJECT" <<'EOF'
+
+if arch(wasm32)
+  import: wasm-libs-without-nix.cabal
+EOF
+            echo "Added to $CABAL_PROJECT"
+            ;;
+        *)
+            cat <<'EOF'
+Skipped. To enable, append to cabal.project:
+
+if arch(wasm32)
+  import: wasm-libs-without-nix.cabal
+EOF
+            ;;
+    esac
+fi