Stabilize WASM Rust build across PHP versions

Author: adamziel

packages/php-ext-wp-mysql-parser/wasm-spike/Dockerfile.rust

@@ -12,56 +12,59 @@
 #   docker build \
 #     --build-arg BASE_IMAGE=playground-php-wasm:compile-extension-php8-4-jspi \
 #     --build-arg HOST_PHP_VERSION=8.4 \
+#     --build-arg HOST_PHP_API_VERSION=20240924 \
 #     -t playground-php-wasm-ext-rust:8.4-jspi \
 #     -f Dockerfile.rust .
 
 ARG BASE_IMAGE=playground-php-wasm:compile-extension-php8-4-jspi
 ARG HOST_PHP_VERSION=8.4
-
-# Stage providing a host PHP CLI binary. ext-php-rs's build.rs shells
-# out to `php` to detect the PHP version (PHP_VERSION_ID drives the cfg
-# flags such as php74, php80, and php85). The wasm-targeted PHP install in
-# /usr/local has no CLI binary (--disable-cli), so copy a matching CLI from
-# the official PHP image for the target version.
-FROM php:${HOST_PHP_VERSION}-cli AS host-php-cli
-
-RUN set -eux; \
-    mkdir -p /opt/host-php/libdeps; \
-    ldd /usr/local/bin/php \
-        | awk '($2 == "=>") { print $3 } ($1 ~ /^\//) { print $1 }' \
-        | grep -v '^$' \
-        | sort -u \
-        | while read -r lib; do cp -L "$lib" /opt/host-php/libdeps/; done
+ARG HOST_PHP_API_VERSION=20240924
 
 FROM ${BASE_IMAGE}
-
-COPY --from=host-php-cli /usr/local/bin/php /opt/host-php/bin/php
-COPY --from=host-php-cli /usr/local/lib/php /opt/host-php/lib/php
-COPY --from=host-php-cli /usr/local/etc/php /opt/host-php/etc/php
-COPY --from=host-php-cli /usr/local/include/php /opt/host-php/include/php
-COPY --from=host-php-cli /opt/host-php/libdeps /opt/host-php/libdeps
+ARG HOST_PHP_VERSION=8.4
+ARG HOST_PHP_API_VERSION=20240924
 
 ENV RUSTUP_HOME=/root/rustup \
     CARGO_HOME=/root/cargo \
     PATH=/root/cargo/bin:/root/rustup/bin:/usr/local/bin:/usr/bin:/bin \
-    LD_LIBRARY_PATH=/opt/host-php/libdeps:/opt/host-php/lib
+    HOST_PHP_VERSION=${HOST_PHP_VERSION} \
+    HOST_PHP_API_VERSION=${HOST_PHP_API_VERSION}
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         curl ca-certificates build-essential \
         libclang-dev clang llvm-dev pkg-config libxml2 libonig5 libsqlite3-0 \
         libargon2-1 libssl3 zlib1g libreadline8 \
-    && rm -rf /var/lib/apt/lists/* \
-    && /opt/host-php/bin/php -v \
-    && ln -sf /opt/host-php/bin/php /usr/local/bin/php-host
+    && rm -rf /var/lib/apt/lists/*
+
+# ext-php-rs shells out to `php -i` for version, debug, and ZTS metadata. The
+# wasm-targeted PHP install in /usr/local has no CLI binary (--disable-cli), and
+# copying a host PHP binary across Debian generations makes this layer depend on
+# incompatible shared libraries. Keep the build contract narrow: report only the
+# phpinfo keys ext-php-rs reads, while `PHP_CONFIG` continues to point at the
+# wasm PHP install for headers and include paths.
+RUN set -eux; \
+    printf '%s\n' \
+        '#!/usr/bin/env bash' \
+        'set -euo pipefail' \
+        'if [ "${1:-}" != "-i" ]; then' \
+        '  echo "php-host-info only supports php -i for ext-php-rs build metadata" >&2' \
+        '  exit 1' \
+        'fi' \
+        'cat <<INFO' \
+        'PHP Version => ${HOST_PHP_VERSION}' \
+        'PHP API => ${HOST_PHP_API_VERSION}' \
+        'Debug Build => no' \
+        'Thread Safety => disabled' \
+        'INFO' \
+        > /usr/local/bin/php-host-info; \
+    chmod +x /usr/local/bin/php-host-info; \
+    /usr/local/bin/php-host-info -i | grep -q "PHP API => ${HOST_PHP_API_VERSION}"
 
-# ext-php-rs's build.rs needs a host `php` executable to query include paths
-# from `php-config`. The wasm-targeted PHP install in /usr/local does not ship
-# a CLI binary (--disable-cli). We install Debian's host php-cli purely so the
-# build script's PHP shells out can run; bindgen still uses
-# /usr/local/bin/php-config (from PATH order) for headers — which IS the wasm
-# PHP install. Set PHP_CONFIG explicitly to make this contract obvious.
+# Set PHP_CONFIG explicitly so bindgen uses the wasm PHP headers from the
+# Playground compile-extension image, not any host PHP package that apt may
+# provide as a transitive dependency.
 ENV PHP_CONFIG=/usr/local/bin/php-config \
-    PHP=/opt/host-php/bin/php
+    PHP=/usr/local/bin/php-host-info
 
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
         | sh -s -- -y --default-toolchain stable --profile minimal \

packages/php-ext-wp-mysql-parser/wasm-spike/build-in-docker-rust.sh

@@ -4,7 +4,7 @@
 #
 #   1. cargo build --release --target wasm32-unknown-emscripten
 #      inside playground-php-wasm-ext-rust:<PHP_VERSION>-<ASYNC>, which
-#      layers rustup + a host PHP 8.4 CLI on top of the Playground
+#      layers rustup + ext-php-rs build metadata on top of the Playground
 #      compile-extension image.
 #   2. Hand the resulting libwp_mysql_parser.a + C shim + config.m4 to
 #      `@php-wasm/compile-extension`, which owns phpize, emconfigure,
@@ -29,6 +29,20 @@ if [ "$ASYNC_MODE" != "jspi" ]; then
   exit 1
 fi
 
+case "$PHP_VERSION" in
+  7.4) PHP_API_VERSION=20190902 ;;
+  8.0) PHP_API_VERSION=20200930 ;;
+  8.1) PHP_API_VERSION=20210902 ;;
+  8.2) PHP_API_VERSION=20220829 ;;
+  8.3) PHP_API_VERSION=20230831 ;;
+  8.4) PHP_API_VERSION=20240924 ;;
+  8.5) PHP_API_VERSION=20250925 ;;
+  *)
+    echo "Unsupported PHP_VERSION: $PHP_VERSION" >&2
+    exit 1
+    ;;
+esac
+
 if [ -z "$PLAYGROUND_REPO" ] || [ ! -f "$PLAYGROUND_REPO/packages/php-wasm/compile-extension/src/cli.ts" ]; then
   echo "PLAYGROUND_REPO must point at a wordpress-playground checkout with packages/php-wasm/compile-extension." >&2
   exit 1
@@ -70,6 +84,7 @@ echo "==> Stage 0: building $RUST_IMAGE"
 docker build \
   --build-arg "BASE_IMAGE=$BASE_IMAGE" \
   --build-arg "HOST_PHP_VERSION=$PHP_VERSION" \
+  --build-arg "HOST_PHP_API_VERSION=$PHP_API_VERSION" \
   -t "$RUST_IMAGE" \
   -f "$SPIKE_DIR/Dockerfile.rust" \
   "$SPIKE_DIR"
@@ -78,6 +93,8 @@ echo "==> Stage 1: cargo build --target wasm32-unknown-emscripten"
 # Feed the container script through stdin so Docker-side comments and strings
 # cannot break host-shell quoting.
 docker run --rm -i \
+  -e "PHP_VERSION=$PHP_VERSION" \
+  -e "PHP_API_VERSION=$PHP_API_VERSION" \
   -v "$CRATE_DIR":/src:ro \
   -v "$OUT_DIR":/out \
   --entrypoint bash \
@@ -124,6 +141,29 @@ docker run --rm -i \
     cargo fetch >/dev/null 2>&1 || true
     REG=$(find /root/cargo/registry/src -maxdepth 1 -type d -name "index.crates.io-*" | head -1)
     chmod -R u+w "$REG"
+
+    if [ "${PHP_VERSION:-}" = "7.4" ]; then
+      # ext-php-rs 0.15's runtime APIs still cover the pieces this extension
+      # uses, but its build-time version table starts at PHP 8.0. Add the
+      # PHP 7.4 Zend API so bindgen can run against Playground's 7.4 headers.
+      perl -0pi -e 's|pub enum ApiVersion \{\n|pub enum ApiVersion {\n    /// PHP 7.4\n    Php74 = 2019_09_02,\n|' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      sed -i 's/ApiVersion::Php80,/ApiVersion::Php74,/' \
+        "$REG/ext-php-rs-0.15.12/build.rs"
+      sed -i '/vec!\[/a \            ApiVersion::Php74,' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      perl -0pi -e 's/(pub fn cfg_name\(self\).*?match self \{\n)/$1            ApiVersion::Php74 => "php74",\n/s' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      perl -0pi -e 's/(pub fn define_name\(self\).*?match self \{\n)/$1            ApiVersion::Php74 => "EXT_PHP_RS_PHP_74",\n/s' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      sed -i '/match version {/a \            x if ((ApiVersion::Php74 as u32)..(ApiVersion::Php80 as u32)).contains(&x) => Ok(ApiVersion::Php74),' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      sed -i 's/cfg(php80, php81/cfg(php74, php80, php81/' \
+        "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      grep -q 'Php74 = 2019_09_02' "$REG/ext-php-rs-build-0.1.1/src/lib.rs"
+      grep -q 'ApiVersion::Php74,' "$REG/ext-php-rs-0.15.12/build.rs"
+    fi
+
     sed -i "s/12 \* std::mem::size_of::<usize>/24 * std::mem::size_of::<usize>/" \
       "$REG/ext-php-rs-0.15.12/src/internal/property.rs"