Full support for RE2 and Abseil!

- Simpler Docker container
- Single Makefile
- Support for -flto
- Proto upgrade to v26.1
- Updated build docs

Signed-off-by: Martijn Stevenson <[email protected]>

Author: martijneken

Dockerfile-sdk

@@ -1,7 +1,6 @@
 FROM ubuntu:noble
 
-COPY ./sdk_container.sh /
-COPY ./build_wasm.sh /
+COPY *.sh /
 COPY *.cc *.h *.js *.proto Makefile* /sdk/
 
 RUN ./sdk_container.sh

Makefile

@@ -1,27 +1,57 @@
-CPP_API ?= .
+ifdef NO_CONTEXT
+  CPP_CONTEXT_LIB =
+else
+  CPP_CONTEXT_LIB = ${PROXY_WASM_CPP_SDK}/proxy_wasm_intrinsics.cc
+endif
 
-all: proxy_wasm_intrinsics.pb.h proxy_wasm_intrinsics_lite.pb.h struct_lite.pb.h ${CPP_API}/libprotobuf.a ${CPP_API}/libprotobuf-lite.a
+PROTOBUF?=none
+ifeq ($(PROTOBUF), full)
+  PROTO_DEPS := protobuf
+  PROTO_OPTS := -DPROXY_WASM_PROTOBUF_FULL=1 \
+		${PROXY_WASM_CPP_SDK}/proxy_wasm_intrinsics.pb.cc
+else ifeq ($(PROTOBUF), lite)
+  PROTO_DEPS := protobuf-lite
+  PROTO_OPTS := -DPROXY_WASM_PROTOBUF_LITE=1 \
+		${PROXY_WASM_CPP_SDK}/proxy_wasm_intrinsics_lite.pb.cc \
+		${PROXY_WASM_CPP_SDK}/struct_lite.pb.cc
+else
+  PROTO_DEPS :=
+  PROTO_OPTS :=
+endif
 
-protobuf: proxy_wasm_intrinsics.pb.h proxy_wasm_intrinsics_lite.pb.h struct_lite.pb.h
+# Provide a list of libraries that the wasm depends on (absl_*, re2, etc).
+WASM_DEPS?=absl_base
 
-proxy_wasm_intrinsics.pb.h: proxy_wasm_intrinsics.proto
-	protoc --cpp_out=. proxy_wasm_intrinsics.proto
+# Determine dependency link options.
+# NOTE: Strip out -pthread which RE2 claims to need...
+PKG_CONFIG?=pkg-config
+PKG_CONFIG_PATH=${EMSDK}/upstream/emscripten/cache/sysroot/lib/pkgconfig
+WASM_LIBS=$(shell $(PKG_CONFIG) $(WASM_DEPS) $(PROTO_DEPS) \
+	  --with-path=$(PKG_CONFIG_PATH) --libs | sed -e 's/-pthread //g')
 
-proxy_wasm_intrinsics_lite.pb.h struct_lite.pb.h: proxy_wasm_intrinsics_lite.proto
-	protoc --cpp_out=. -I. proxy_wasm_intrinsics_lite.proto
-	protoc --cpp_out=. struct_lite.proto
+debug-deps:
+	# WASM_DEPS : ${WASM_DEPS}
+	# WASM_LIBS : ${WASM_LIBS}
+	# PROTO_DEPS: ${PROTO_DEPS}
+	# PROTO_OPTS: ${PROTO_OPTS}
 
-${CPP_API}/libprotobuf.a ${CPP_API}/libprotobuf-lite.a:
-	rm -rf protobuf-wasm \
-	&& git clone https://github.com/protocolbuffers/protobuf protobuf-wasm \
-	&& cd protobuf-wasm \
-	&& git checkout v3.9.1 \
-	&& ./autogen.sh \
-	&& emconfigure ./configure --disable-shared CXXFLAGS="-O3 -flto" \
-	&& emmake make \
-	&& cd .. \
-	&& cp protobuf-wasm/src/.libs/libprotobuf-lite.a ${CPP_API}/libprotobuf-lite.a \
-	&& cp protobuf-wasm/src/.libs/libprotobuf.a ${CPP_API}/libprotobuf.a
+# TODO(martijneken): Add Emscripten stack/heap size params.
+%.wasm %.wat: %.cc
+	em++ --no-entry -sSTANDALONE_WASM -sEXPORTED_FUNCTIONS=_malloc \
+		--std=c++17 -O3 -flto \
+		--js-library ${PROXY_WASM_CPP_SDK}/proxy_wasm_intrinsics.js \
+		-I${PROXY_WASM_CPP_SDK} \
+		${CPP_CONTEXT_LIB} \
+		${PROTO_OPTS} \
+		${WASM_LIBS} \
+		$*.cc -o $*.wasm
 
 clean:
-	rm -f proxy_wasm_intrinsics.pb.h proxy_wasm_intrinsics_lite.pb.h struct_lite.pb.h ${CPP_API}/libprotobuf.a ${CPP_API}/libprotobuf-lite.a
+	rm *.wasm
+
+# NOTE: How to regenerate .pb.h and .pb.cc files for a protobuf update:
+# - download + extract protobuf release (currently v26.1)
+# - regenerate:
+#   ./bin/protoc --cpp_out=../ -I../ -Iinclude/google/protobuf/ ../struct_lite.proto
+#   ./bin/protoc --cpp_out=../ -I../ -Iinclude/google/protobuf/ ../proxy_wasm_intrinsics_lite.proto
+#   ./bin/protoc --cpp_out=../ -I../ -Iinclude/google/protobuf/ ../proxy_wasm_intrinsics.proto

Makefile.base

@@ -16,14 +16,11 @@ load("@emsdk//emscripten_toolchain:wasm_rules.bzl", "wasm_cc_binary")
 load("@rules_cc//cc:defs.bzl", "cc_binary")
 
 def _optimized_wasm_cc_binary_transition_impl(settings, attr):
-    # TODO(PiotrSikora): Add -flto to copts/linkopts when fixed in emsdk.
-    # See: https://github.com/emscripten-core/emsdk/issues/971
-    #
     # Define STANDALONE_WASM at compile time as well as link time (below).
     # This fixes Abseil by not including Emscripten JS stacktraces + symbolization.
     # TODO(martijneken): Remove after Abseil stops using this define.
     return {
-        "//command_line_option:copt": ["-O3", "-DSTANDALONE_WASM"],
+        "//command_line_option:copt": ["-O3", "-flto", "-DSTANDALONE_WASM"],
         "//command_line_option:cxxopt": [],
         "//command_line_option:linkopt": [],
         "//command_line_option:collect_code_coverage": False,
@@ -95,6 +92,7 @@ def proxy_wasm_cc_binary(
         linkopts = linkopts + [
             "--no-entry",
             "--js-library=$(location @proxy_wasm_cpp_sdk//:proxy_wasm_intrinsics_js)",
+            "-sSTANDALONE_WASM",
             "-sEXPORTED_FUNCTIONS=_malloc",
         ],
         tags = tags + [

Makefile.base_lite

@@ -16,4 +16,4 @@
 
 source /root/emsdk/emsdk_env.sh
 export PATH=/usr/local/bin:$PATH
-make
+make "$@"

bazel/defs.bzl

@@ -1,8 +1,8 @@
 # Proxy-Wasm C++ SDK Build Instructions
 
 The C++ SDK has dependencies on specific versions of the C++ WebAssembly
-toolchain [Emscripten](https://emscripten.org) and the protobuf library,
-therefore use of a Docker image is recommended.
+toolchain [Emscripten](https://emscripten.org). Use of a Docker image is
+recommended to achieve repeatable builds and save work.
 
 ## Docker
 
@@ -11,7 +11,7 @@ A Dockerfile for the C++ SDK is provided in [Dockerfile-sdk](../Dockerfile-sdk).
 It can built in this repository's root directory by:
 
 ```bash
-docker build -t wasmsdk:v2 -f Dockerfile-sdk .
+docker build -t wasmsdk:v3 -f Dockerfile-sdk .
 ```
 
 The docker image can be used for compiling C++ plugin code into Wasm modules.
@@ -23,12 +23,10 @@ Create a directory with your source files and a Makefile:
 ```makefile
 PROXY_WASM_CPP_SDK=/sdk
 
-all: myproject.wasm
-
-include ${PROXY_WASM_CPP_SDK}/Makefile.base_lite
+include ${PROXY_WASM_CPP_SDK}/Makefile
 ```
 
-Source file (myproject.cc):
+Create a C++ source file (myproject.cc):
 
 ```c++
 #include <string>
@@ -57,10 +55,26 @@ void ExampleContext::onDone() { logInfo("onDone " + std::to_string(id())); }
 
 ### Compiling with the Docker build image
 
-Run docker:
+Run docker to build wasm, using a target with a .wasm suffix:
 
 ```bash
-docker run -v $PWD:/work -w /work  wasmsdk:v2 /build_wasm.sh
+docker run -v $PWD:/work -w /work wasmsdk:v3 /build_wasm.sh myproject.wasm
+```
+
+You can specify wasm dependencies via these Makefile variables:
+
+-   PROTOBUF = {full, lite, none}
+-   WASM_DEPS = list of libraries
+
+For example:
+
+```makefile
+PROXY_WASM_CPP_SDK=/sdk
+
+PROTOBUF=lite
+WASM_DEPS=re2 absl_strings
+
+include ${PROXY_WASM_CPP_SDK}/Makefile
 ```
 
 ### Caching the standard libraries
@@ -70,7 +84,7 @@ cache these in the docker image, after the first successful compilation (e.g
 myproject.cc above), commit the image with the standard libraries:
 
 ```bash
-docker commit `docker ps -l | grep wasmsdk:v2 | awk '{print $1}'` wasmsdk:v2
+docker commit `docker ps -l | grep wasmsdk:v3 | awk '{print $1}'` wasmsdk:v3
 ```
 
 This will save time on subsequent compiles.
@@ -86,48 +100,32 @@ PROXY_WASM_CPP_SDK=/sdk
 all: myproject.wasm
   chown ${uid}.${gid} $^
 
-include ${PROXY_WASM_CPP_SDK}/Makefile.base_lite
+include ${PROXY_WASM_CPP_SDK}/Makefile
 ```
 
 Invocation file (e.g. build.sh):
 
 ```bash
 #!/bin/bash
-docker run -e uid="$(id -u)" -e gid="$(id -g)" -v $PWD:/work -w /work wasmsdk:v2 /build_wasm.sh
+docker run -e uid="$(id -u)" -e gid="$(id -g)" -v $PWD:/work -w /work wasmsdk:v3 /build_wasm.sh
 ```
 
 ## Dependencies for building Wasm modules:
 
 If you do not wish to use the Docker image, the dependencies can be installed by
-script (sdk\_container.sh), or by hand.
-
-### protobuf v3.9.1
-
-You must install the version of protobuf on your build system that matches the
-libprotobuf.a files (without any patches) so that the generated code matches the
-.a library.  Currently this is based on tag v3.9.1 of
-https://github.com/protocolbuffers/protobuf.
-
-```bash
-git clone https://github.com/protocolbuffers/protobuf
-cd protobuf
-git checkout v3.9.1
-git submodule update --init --recursive
-./autogen.sh
-./configure
-make
-make check
-sudo make install
-```
+script (sdk\_container.sh), or by hand. First you need Emscripten to build
+everything else. Then you can build other wasm-compatible libraries, such as
+protobuf, abseil, and RE2.
 
 ### Emscripten
 
+Version 3.1.67 is known to work:
+
 ```bash
 git clone https://github.com/emscripten-core/emsdk.git
 cd emsdk
 git checkout 3.1.67
-
-./emsdk install 3.1.67
+./emsdk install --shallow 3.1.67
 ./emsdk activate 3.1.67
 
 source ./emsdk_env.sh
@@ -140,26 +138,3 @@ It is possible later versions will work, e.g.
 ./emsdk install latest
 ./emsdk activate latest
 ```
-
-However 3.1.67 is known to work.
-
-### Rebuilding the libprotobuf.a files
-
-To build the protobuf static libraries for use in your proxy-wasm wasm module,
-if you need them, you may use Emscripten in the same way sdk\_container.sh does
-it:
-
-```bash
-git clone https://github.com/protocolbuffers/protobuf protobuf-wasm
-cd protobuf-wasm
-git checkout v3.9.1
-git submodule update --init --recursive
-./autogen.sh
-emconfigure ./configure --disable-shared CXXFLAGS="-O3 -flto"
-emmake make
-cd ..
-cp protobuf-wasm/src/.libs/libprotobuf-lite.a ${CPP_API}/libprotobuf-lite.a
-cp protobuf-wasm/src/.libs/libprotobuf.a ${CPP_API}/libprotobuf.a
-```
-
-Note: ensure /usr/local/bin is in your path.

build_wasm.sh

@@ -0,0 +1,43 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "proxy_wasm_intrinsics.h"
+
+class MyRootContext : public RootContext {
+public:
+  explicit MyRootContext(uint32_t id, std::string_view root_id) : RootContext(id, root_id) {}
+
+  bool onStart(size_t) override {
+#if defined(PROXY_WASM_PROTOBUF_FULL)
+    LOG_TRACE("onStart with protobuf (full)");
+    google::protobuf::Value value;
+    value.set_string_value("unused");
+#elif defined(PROXY_WASM_PROTOBUF_LITE)
+    LOG_TRACE("onStart with protobuf (lite)");
+    google::protobuf::Value value;
+    value.set_string_value("unused");
+#else
+    LOG_TRACE("onStart without protobuf");
+#endif
+    return true;
+  }
+};
+
+class MyHttpContext : public Context {
+public:
+  explicit MyHttpContext(uint32_t id, RootContext *root) : Context(id, root) {}
+};
+
+static RegisterContextFactory register_StaticContext(CONTEXT_FACTORY(MyHttpContext),
+                                                     ROOT_FACTORY(MyRootContext));

docs/building.md

@@ -0,0 +1,52 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "proxy_wasm_intrinsics.h"
+#include "re2/re2.h"
+
+class MyRootContext : public RootContext {
+public:
+  explicit MyRootContext(uint32_t id, std::string_view root_id) : RootContext(id, root_id) {}
+
+  bool onConfigure(size_t) override {
+    // Compile the regex expression at plugin setup time.
+    path_match.emplace("/foo-([^/]+)/");
+    return path_match->ok();
+  }
+
+  std::optional<re2::RE2> path_match;
+};
+
+class MyHttpContext : public Context {
+public:
+  explicit MyHttpContext(uint32_t id, RootContext *root)
+      : Context(id, root), root_(static_cast<MyRootContext *>(root)) {}
+
+  FilterHeadersStatus onRequestHeaders(uint32_t headers, bool end_of_stream) override {
+    auto path = getRequestHeader(":path");
+    if (path) {
+      std::string edit = path->toString(); // mutable copy
+      if (re2::RE2::Replace(&edit, *root_->path_match, "/\\1/")) {
+        replaceRequestHeader(":path", edit);
+      }
+    }
+    return FilterHeadersStatus::Continue;
+  }
+
+private:
+  const MyRootContext *root_;
+};
+
+static RegisterContextFactory register_StaticContext(CONTEXT_FACTORY(MyHttpContext),
+                                                     ROOT_FACTORY(MyRootContext));