webrtc-sys: build libwebrtc from source on Linux

Be-ing · Be-ing · commit 1b4dda66dc6d · 2025-12-03T02:10:38.000-06:00
diff --git a/webrtc-sys/build.rs b/webrtc-sys/build.rs
@@ -81,7 +81,59 @@ fn main() {
         "src/desktop_capturer.cpp",
     ]);
 
-    let webrtc_dir = webrtc_sys_build::webrtc_dir();
+    let mut webrtc_dir = webrtc_sys_build::webrtc_dir();
+    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+
+    #[cfg(target_os = "linux")]
+    println!("cargo:rerun-if-env-changed=LK_LIBWEBRTC_SOURCE");
+    #[cfg(target_os = "linux")]
+    if let Ok(source_archive) = env::var("LK_LIBWEBRTC_SOURCE") {
+        let out_dir = env::var("OUT_DIR").unwrap();
+        let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+
+        fn check_command_output(output: std::process::Output) {
+            let status = output.status;
+            if !status.success() {
+                let stderr = String::from_utf8_lossy(&output.stderr);
+                let stdout = String::from_utf8_lossy(&output.stdout);
+                panic!("Command exited unsuccessfully: {status:?},\nstdout:\n{stdout}\nstderr:\n{stderr}");
+            }
+        }
+
+        if !std::fs::exists(format!("{out_dir}/src")).unwrap() {
+            check_command_output(
+                Command::new("tar")
+                    .args(["-Jxf", &source_archive, "-C", &out_dir])
+                    .output()
+                    .unwrap(),
+            );
+        }
+
+        let script_arch = match target_arch.as_str() {
+            "x86_64" => "x64",
+            "aarch64" => "arm64",
+            a => a,
+        };
+        check_command_output(
+            Command::new("bash")
+                .args([
+                    &format!("{manifest_dir}/libwebrtc/build_linux.sh"),
+                    "--sources",
+                    &format!("{out_dir}/src"),
+                    "--toolchain",
+                    "gnu",
+                    "--arch",
+                    script_arch,
+                    "--profile",
+                    "release",
+                ])
+                .output()
+                .unwrap(),
+        );
+
+        webrtc_dir = PathBuf::from(format!("{out_dir}/linux-{script_arch}-release"));
+    }
+
     let webrtc_include = webrtc_dir.join("include");
     let webrtc_lib = webrtc_dir.join("lib");
 
@@ -112,7 +164,6 @@ fn main() {
     println!("cargo:rustc-link-lib=static=webrtc");
 
     let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
-    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
     match target_os.as_str() {
         "windows" => {
             println!("cargo:rustc-link-lib=dylib=msdmo");
diff --git a/webrtc-sys/build/src/lib.rs b/webrtc-sys/build/src/lib.rs
@@ -18,7 +18,7 @@ use std::{
     env,
     fs::{self, File},
     io::{self, BufRead, Write},
-    path,
+    path::{self, Path},
     process::Command,
 };
 
@@ -115,14 +115,15 @@ pub fn webrtc_dir() -> path::PathBuf {
     prebuilt_dir()
 }
 
-pub fn webrtc_defines() -> Vec<(String, Option<String>)> {
+pub fn webrtc_defines(path: impl AsRef<Path>) -> Vec<(String, Option<String>)> {
+    let path = path.as_ref();
     // read preprocessor definitions from webrtc.ninja
     let defines_re = Regex::new(r"-D(\w+)(?:=([^\s]+))?").unwrap();
-    let mut files = vec![webrtc_dir().join("webrtc.ninja")];
+    let mut files = vec![path.join("webrtc.ninja")];
     // include desktop_capture.ninja to avoid ABI mismatch for DesktopCaptureOptions due to WEBRTC_USE_X11 missing
     // libwebrtc does not implement desktop capture on Android
     if env::var("CARGO_CFG_TARGET_OS").unwrap() != "android" {
-        files.push(webrtc_dir().join("desktop_capture.ninja"));
+        files.push(path.join("desktop_capture.ninja"));
     }
 
     let mut seen = HashSet::new();
diff --git a/webrtc-sys/libwebrtc/build_linux.sh b/webrtc-sys/libwebrtc/build_linux.sh
@@ -20,12 +20,12 @@ toolchain="gnu"
 
 while [ "$#" -gt 0 ]; do
   case "$1" in
+    --sources)
+      sources="$(realpath $2)"
+      shift 2
+      ;;
     --arch)
       arch="$2"
-      if [ "$arch" != "x64" ] && [ "$arch" != "arm64" ]; then
-        echo "Error: Invalid value for --arch. Must be 'x64' or 'arm64'."
-        exit 1
-      fi
       shift 2
       ;;
     --profile)
@@ -56,14 +56,20 @@ if [ -z "$arch" ]; then
   exit 1
 fi
 
+if [ -z "$sources" ]; then
+  echo "Error: --sources must be set."
+  exit 1
+fi
+
 echo "Building LiveKit WebRTC - Linux"
 echo "Arch: $arch"
 echo "Profile: $profile"
 echo "Toolchain: $toolchain"
 
-export COMMAND_DIR=$(cd $(dirname $0); pwd)
-export OUTPUT_DIR="$(pwd)/build-$arch-$profile"
-export ARTIFACTS_DIR="$(pwd)/linux-$arch-$profile"
+COMMAND_DIR=$(cd $(dirname $0); pwd)
+OUTPUT_DIR="$(dirname "$sources")"
+BUILD_DIR="$OUTPUT_DIR/build-$arch-$profile"
+ARTIFACTS_DIR="$OUTPUT_DIR/linux-$arch-$profile"
 
 if [ "$toolchain" == "gnu" ]; then
   [ -n "$CC" ] || export CC="$(which gcc)"
@@ -91,39 +97,12 @@ elif [ "$toolchain" == "llvm" ]; then
   custom_toolchain=\"//build/toolchain/linux/unbundle:default\" \
   host_toolchain=\"//build/toolchain/linux/unbundle:default\""
 elif [ "$toolchain" == "chromium-llvm" ]; then
-  AR="$COMMAND_DIR/src/third_party/llvm-build/Release+Asserts/bin/llvm-ar"
-  OBJCOPY="$COMMAND_DIR/src/third_party/llvm-build/Release+Asserts/bin/llvm-objcopy"
+  AR="$sources/third_party/llvm-build/Release+Asserts/bin/llvm-ar"
+  OBJCOPY="$sources/third_party/llvm-build/Release+Asserts/bin/llvm-objcopy"
   chromium_libcxx=true
   toolchain_gn_args="is_clang=true use_custom_libcxx=true"
 fi
 
-set -x
-
-if [ ! -e "$(pwd)/depot_tools" ]
-then
-  git clone --depth 1 https://chromium.googlesource.com/chromium/tools/depot_tools.git
-fi
-
-# must be done after runing `which` to find toolchain's executables above
-export PATH="$(pwd)/depot_tools:$PATH"
-
-if [ ! -e "$(pwd)/src" ]; then
-  # use --nohooks to avoid the download_from_google_storage hook that takes > 6 minutes
-  # then manually run the other hooks
-  gclient sync -D --no-history --nohooks
-  python3 src/tools/rust/update_rust.py
-  if [ "$toolchain" == "chromium-llvm" ] || [ "$toolchain" == "llvm" ]; then
-    python3 src/tools/clang/scripts/update.py
-  fi
-fi
-
-cd src
-git apply "$COMMAND_DIR/patches/add_licenses.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
-git apply "$COMMAND_DIR/patches/ssl_verify_callback_with_native_handle.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
-git apply "$COMMAND_DIR/patches/add_deps.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
-git apply "$COMMAND_DIR/patches/david_disable_gun_source_macro.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
-cd ..
-
 debug="false"
 if [ "$profile" = "debug" ]; then
   debug="true"
@@ -156,30 +135,31 @@ args="is_debug=$debug  \
   rtc_use_x11=true \
   $toolchain_gn_args"
 
-set -e
+set -xe
 
 # generate ninja files
-gn gen "$OUTPUT_DIR" --root="src" --args="${args}"
+export PATH="$sources/depot_tools:$PATH"
+gn gen "$BUILD_DIR" --root="$sources" --args="${args}"
 
 # build static library
-ninja -C "$OUTPUT_DIR" :default
+ninja -C "$BUILD_DIR" :default
 
 mkdir -p "$ARTIFACTS_DIR/lib"
 
 # make libwebrtc.a
 # don't include nasm
-"$AR" -rc "$ARTIFACTS_DIR/lib/libwebrtc.a" `find "$OUTPUT_DIR/obj" -name '*.o' -not -path "*/third_party/nasm/*"`
+"$AR" -rc "$ARTIFACTS_DIR/lib/libwebrtc.a" `find "$BUILD_DIR/obj" -name '*.o' -not -path "*/third_party/nasm/*"`
 "$OBJCOPY" --redefine-syms="$COMMAND_DIR/boringssl_prefix_symbols.txt" "$ARTIFACTS_DIR/lib/libwebrtc.a"
 
-python3 "./src/tools_webrtc/libs/generate_licenses.py" \
-  --target :default "$OUTPUT_DIR" "$OUTPUT_DIR"
+python3 "$sources/tools_webrtc/libs/generate_licenses.py" \
+  --target :default "$BUILD_DIR" "$BUILD_DIR"
 
-cp "$OUTPUT_DIR/obj/webrtc.ninja" "$ARTIFACTS_DIR"
-cp "$OUTPUT_DIR/obj/modules/desktop_capture/desktop_capture.ninja" "$ARTIFACTS_DIR"
-cp "$OUTPUT_DIR/args.gn" "$ARTIFACTS_DIR"
-cp "$OUTPUT_DIR/LICENSE.md" "$ARTIFACTS_DIR"
+cp "$BUILD_DIR/obj/webrtc.ninja" "$ARTIFACTS_DIR"
+cp "$BUILD_DIR/obj/modules/desktop_capture/desktop_capture.ninja" "$ARTIFACTS_DIR"
+cp "$BUILD_DIR/args.gn" "$ARTIFACTS_DIR"
+cp "$BUILD_DIR/LICENSE.md" "$ARTIFACTS_DIR"
 
-cd src
+cd $sources
 if [ $chromium_libcxx == "true" ]; then
   mkdir -p "$ARTIFACTS_DIR/include/buildtools/third_party"
   cp -R buildtools/third_party/libc++ "$ARTIFACTS_DIR/include/buildtools/third_party"
diff --git a/webrtc-sys/libwebrtc/generate-source-archive.sh b/webrtc-sys/libwebrtc/generate-source-archive.sh
@@ -0,0 +1,144 @@
+#!/bin/bash
+
+COMMAND_DIR="$(cd $(dirname $0); pwd)"
+SOURCE_DIR="$COMMAND_DIR/src"
+ARCHIVE_PATH="$COMMAND_DIR/libwebrtc-source.tar.xz"
+
+set -x
+
+# for debugging this script
+reset() {
+    rm -rf "$SOURCE_DIR" "$COMMAND_DIR/depot_tools" "$ARCHIVE_PATH"
+}
+
+download() {
+    cd "$COMMAND_DIR"
+    git clone --depth 1 https://chromium.googlesource.com/chromium/tools/depot_tools.git
+    # use --nohooks to avoid the download_from_google_storage hook that takes > 6 minutes
+    # then manually run the other hooks
+    export PATH="$COMMAND_DIR/depot_tools:$PATH"
+    gclient sync -D --no-history --nohooks
+    python3 "$SOURCE_DIR/tools/rust/update_rust.py"
+    python3 "$SOURCE_DIR/tools/clang/scripts/update.py"
+    mv depot_tools src
+}
+
+patch() {
+    cd $SOURCE_DIR
+    git apply "$COMMAND_DIR/patches/add_licenses.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
+    git apply "$COMMAND_DIR/patches/ssl_verify_callback_with_native_handle.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
+    git apply "$COMMAND_DIR/patches/add_deps.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
+    cd third_party
+    git apply "$COMMAND_DIR/patches/david_disable_gun_source_macro.patch" -v --ignore-space-change --ignore-whitespace --whitespace=nowarn
+}
+
+clean() {
+    required_files_and_dirs=(
+        abseil-cpp
+        boringssl
+        catapult
+        closure_compiler
+        dav1d
+        ffmpeg
+        freetype
+        googletest
+        harfbuzz-ng
+        icu
+        jsoncpp
+        libaom
+        libjpeg_turbo
+        libjpeg.gni
+        BUILD.gn
+        libpng
+        libsrtp
+        libvpx
+        libyuv
+        nasm
+        openh264
+        opus
+        perfetto
+        protobuf
+        protobuf-javascript
+        rust
+        rust-toolchain
+        zlib
+        fuzztest
+        crc32c
+        pffft
+        re2
+        google_benchmark
+        rnnoise
+    )
+    for filename in $(ls -1 "$SOURCE_DIR/third_party"); do
+        if ! [[ ${required_files_and_dirs[@]} =~ $filename ]]; then
+            rm -rf "$SOURCE_DIR/third_party/$filename"
+        fi
+    done
+
+    third_party_dirs=(
+        rust-toolchain/bin
+        rust-toolchain/lib
+        catapult/tracing/test_data
+        catapult/third_party/vinn/third_party/v8
+        catapult/third_party/gsutil
+        rust/chromium_crates_io
+        boringssl/src/third_party/wycheproof_testvectors
+        openh264/src/res
+        ffmpeg/tests
+        harfbuzz-ng/src/test
+        harfbuzz-ng/src/perf
+        perfetto/src/traced/probes/ftrace/test
+        perfetto/src/trace_processor
+        perfetto/docs
+        perfetto/test
+        perfetto/ui
+        icu/source/data
+        icu/source/test
+        icu/source
+        boringssl/src/crypto/cipher/test
+        boringssl/src/fuzz
+        opus/src/dnn/torch/osce/resources
+        nasm/travis
+        nasm/test
+        closure_compiler/compiler
+    )
+    for dir in "${third_party_dirs[@]}"; do
+        rm -rf "$SOURCE_DIR/third_party/$dir"
+    done
+
+    src_dirs=(
+        depot_tools/.cipd_bin
+        depot_tools/.cipd_client
+        buildtools/reclient
+        tools/perf/testdata
+        tools/luci-go
+        tools/metrics
+        tools/resultdb
+        tools/perf/page_sets
+        tools/perf/core/shard_maps/timing_data
+        tools/disable_tests/tests
+        data
+        base/test
+    )
+    for dir in "${src_dirs[@]}"; do
+        rm -rf "$SOURCE_DIR/$dir"
+    done
+
+    dir_names=(testdata test_data doc docs \.git)
+        for dir_name in "${dir_names[@]}"; do
+            for dir in $(find "$SOURCE_DIR" -name $dir_name); do
+                rm -rf "$dir"
+            done
+    done
+}
+
+package() {
+    tar -Jcf "$ARCHIVE_PATH" -C "$COMMAND_DIR" src
+}
+
+reset
+set -e
+download
+patch
+clean
+package
