Drop `cargo rustc` in favor of using $RUSTFLAGS

cargo rustc only passes the given arguments to the linking rustc,
not any building rustc calls, which is not generally what we want.

This further reduces `liblightningjs_release.wasm` from 2.4MB to
2.3 MB.

diff --git a/genbindings.sh b/genbindings.sh
index edaa01d50de3b871a219fd637e2115653e649bae..45af05a3bfae75bc5f827e4af5a9450a810b1232 100755 (executable)
--- a/genbindings.sh
+++ b/genbindings.sh
@@ -460,7 +460,7 @@ fi
 # Now build with LTO on on both C++ and rust, but without cross-language LTO:
 # Clear stale release build artifacts from previous runs
 cargo clean --release
-CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release -- -C lto
+CARGO_PROFILE_RELEASE_LTO=true RUSTFLAGS="$RUSTFLAGS -C embed-bitcode=yes -C lto" cargo build $CARGO_BUILD_ARGS -v --release
 if [ "$2" = "true" ]; then
        clang++ $LOCAL_CFLAGS -std=c++11 -O2 demo.cpp target/release/libldk.a -ldl
 fi
@@ -486,9 +486,9 @@ if [ "$2" = "false" -a "$(rustc --print target-list | grep wasm32-wasi)" != "" ]
        if clang -nostdlib -o /dev/null --target=wasm32-wasi -Wl,--no-entry genbindings_wasm_test_file.c > /dev/null 2>&1; then
                # And if it does, build a WASM binary without capturing errors
                export CFLAGS_wasm32_wasi="$BASE_CFLAGS -target wasm32 -O1"
-               RUSTFLAGS="$RUSTFLAGS --cfg=test_mod_pointers" cargo rustc $CARGO_BUILD_ARGS -v --target=wasm32-wasi
+               RUSTFLAGS="$RUSTFLAGS --cfg=test_mod_pointers" cargo build $CARGO_BUILD_ARGS -v --target=wasm32-wasi
                export CFLAGS_wasm32_wasi="$BASE_CFLAGS -fembed-bitcode -target wasm32 -Oz"
-               CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release --target=wasm32-wasi -- -C embed-bitcode=yes -C opt-level=z -C linker-plugin-lto -C lto
+               RUSTFLAGS="$RUSTFLAGS -C embed-bitcode=yes -C opt-level=z -C linker-plugin-lto -C lto" CARGO_PROFILE_RELEASE_LTO=true cargo build $CARGO_BUILD_ARGS -v --release --target=wasm32-wasi
        else
                echo "Cannot build WASM lib as clang does not seem to support the wasm32-wasi target"
        fi
@@ -507,7 +507,7 @@ for IDX in ${!EXTRA_TARGETS[@]}; do
        EXTRA_ENV_TARGET=$(echo "${EXTRA_TARGETS[$IDX]}" | sed 's/-/_/g')
        export CFLAGS_$EXTRA_ENV_TARGET="$BASE_CFLAGS"
        export CC_$EXTRA_ENV_TARGET=${EXTRA_CCS[$IDX]}
-       RUSTFLAGS="$BASE_RUSTFLAGS -C linker=${EXTRA_CCS[$IDX]}" CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release --target "${EXTRA_TARGETS[$IDX]}" -- -C lto
+       RUSTFLAGS="$BASE_RUSTFLAGS -C embed-bitcode=yes -C lto -C linker=${EXTRA_CCS[$IDX]}" CARGO_PROFILE_RELEASE_LTO=true cargo build $CARGO_BUILD_ARGS -v --release --target "${EXTRA_TARGETS[$IDX]}"
 done
 
 if [ "$CLANGPP" != "" -a "$LLD" != "" ]; then
@@ -525,12 +525,12 @@ if [ "$CLANGPP" != "" -a "$LLD" != "" ]; then
                done
                export CFLAGS_aarch64_apple_darwin="$CFLAGS_aarch64_apple_darwin -O3 -fPIC -fembed-bitcode"
                LINK_ARG_FLAGS="$LINK_ARG_FLAGS -C link-arg="-isysroot$(xcrun --show-sdk-path)" -C link-arg=-mmacosx-version-min=10.9"
-               RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=apple-a14" CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release --target aarch64-apple-darwin -- -C linker-plugin-lto -C lto -C linker=$CLANG $LINK_ARG_FLAGS -C link-arg=-mcpu=apple-a14
+               RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=apple-a14 -C embed-bitcode=yes -C linker-plugin-lto -C lto -C linker=$CLANG $LINK_ARG_FLAGS -C link-arg=-mcpu=apple-a14" CARGO_PROFILE_RELEASE_LTO=true cargo build $CARGO_BUILD_ARGS -v --release --target aarch64-apple-darwin
        fi
        export CFLAGS_$ENV_TARGET="$BASE_CFLAGS -O3 -fPIC -fembed-bitcode -march=sandybridge -mcpu=sandybridge -mtune=sandybridge"
        # Rust doesn't recognize CFLAGS changes, so we need to clean build artifacts
        cargo clean --release
-       CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release -- -C linker-plugin-lto -C lto -C linker=$CLANG $LINK_ARG_FLAGS -C link-arg=-march=sandybridge -C link-arg=-mcpu=sandybridge -C link-arg=-mtune=sandybridge
+       CARGO_PROFILE_RELEASE_LTO=true RUSTFLAGS="$RUSTFLAGS -C embed-bitcode=yes -C linker-plugin-lto -C lto -C linker=$CLANG $LINK_ARG_FLAGS -C link-arg=-march=sandybridge -C link-arg=-mcpu=sandybridge -C link-arg=-mtune=sandybridge" cargo build $CARGO_BUILD_ARGS -v --release
 
        if [ "$2" = "true" ]; then
                $CLANGPP $LOCAL_CFLAGS -flto -fuse-ld=$LLD -O2 demo.cpp target/release/libldk.a -ldl
@@ -541,7 +541,7 @@ if [ "$CLANGPP" != "" -a "$LLD" != "" ]; then
        fi
 else
        if [ "$CFLAGS_aarch64_apple_darwin" != "" ]; then
-               RUSTFLAGS="$BASE_RUSTFLAGS -C target-cpu=apple-a14" CARGO_PROFILE_RELEASE_LTO=true cargo rustc $CARGO_BUILD_ARGS -v --release --target aarch64-apple-darwin -- -C lto
+               RUSTFLAGS="$BASE_RUSTFLAGS -C embed-bitcode=yes -C lto -C target-cpu=apple-a14" CARGO_PROFILE_RELEASE_LTO=true cargo build $CARGO_BUILD_ARGS -v --release --target aarch64-apple-darwin
        fi
        echo "WARNING: Building with cross-language LTO is not avilable without clang-$RUSTC_LLVM_V"
 fi