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Merge pull request #21 from rucoder/rucoder/riscv-support
Enable riscv support
2 parents 2f8b817 + d410be7 commit c2b87e1

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‎Dockerfile‎

Lines changed: 119 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -24,37 +24,140 @@ ADD config.toml /usr/local/cargo/
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RUN cargo install --root /cargo-cross cargo-chef@0.1.71 cargo-sbom@0.9.1
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FROM rust:${RUST_VERSION}-alpine3.20 AS tools-target-base
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# ---------------------------------------------------------------------------
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# Extract the riscv64 linker inputs that rustup's tier-1 musl targets
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# normally ship in <sysroot>/lib/rustlib/<target>/lib/self-contained/:
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# - musl startup objects: Scrt1.o, crt1.o, crti.o, crtn.o, rcrt1.o
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# - libc.a (from musl-dev)
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# - libunwind.a (from llvm-libunwind-static)
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# - libgcc runtime startup: crtbegin.o, crtbeginS.o, crtend.o, crtendS.o
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# (from Alpine gcc — rustc's linux_musl target spec emits these as
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# bare filenames to the linker, so they must be findable via -L at link
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# time; rustup's self-contained dir is added to -L automatically.)
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# None of these come from `-Z build-std` (which only builds Rust crates).
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# Without this bundle, rustc's linker invocation falls back to clang's host
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# library search (/usr/lib on amd64), silently picking up amd64 artifacts.
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# ---------------------------------------------------------------------------
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FROM --platform=linux/riscv64 alpine:3.22 AS riscv64-musl-crt
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RUN apk add --no-cache musl-dev llvm-libunwind-static gcc
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RUN mkdir -p /crt-out && \
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cp /usr/lib/Scrt1.o /usr/lib/crt1.o /usr/lib/crti.o /usr/lib/crtn.o /usr/lib/rcrt1.o \
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/usr/lib/libc.a /usr/lib/libunwind.a \
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/crt-out/ && \
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cp /usr/lib/gcc/riscv64-alpine-linux-musl/*/crtbegin.o \
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/usr/lib/gcc/riscv64-alpine-linux-musl/*/crtbeginS.o \
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/usr/lib/gcc/riscv64-alpine-linux-musl/*/crtend.o \
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/usr/lib/gcc/riscv64-alpine-linux-musl/*/crtendS.o \
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/crt-out/ && \
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ls -la /crt-out
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# ---------------------------------------------------------------------------
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# Build std/core/alloc/proc_macro for the tier-3 riscv64gc-unknown-linux-musl
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# target. The resulting rlibs are copied into the final image's rustup sysroot
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# so downstream builds see the target as fully installed (no -Z build-std,
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# no RUSTC_BOOTSTRAP, no rust-src needed downstream).
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# ---------------------------------------------------------------------------
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FROM --platform=$BUILDPLATFORM rust:${RUST_VERSION}-alpine3.22 AS riscv64-std-builder
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RUN rustup target add riscv64gc-unknown-linux-musl && \
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rustup component add rust-src
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RUN apk add musl-dev linux-headers make clang llvm lld mold
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ENV PATH=/usr/lib/llvm/bin:$PATH
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ENV CC_riscv64gc_unknown_linux_musl=clang \
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CFLAGS_riscv64gc_unknown_linux_musl="--target=riscv64-unknown-linux-musl" \
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AR_riscv64gc_unknown_linux_musl=llvm-ar \
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RANLIB_riscv64gc_unknown_linux_musl=llvm-ranlib
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# allow `-Z` flags on stable rust
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ENV RUSTC_BOOTSTRAP=1
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# Build std (and its deps: core, alloc, proc_macro) for the riscv64 musl
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# target by compiling a tiny dummy crate with `-Z build-std`. The compiled
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# rlibs end up under target/<triple>/release/deps and we then assemble them
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# into a rustup-style sysroot layout at /sysroot-out.
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WORKDIR /build-std
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RUN cargo init --lib --name dummy_std_build .
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# Configure cross-compilation for the dummy crate (mirrors final image config)
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RUN mkdir -p .cargo && printf '%s\n' \
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'[target.riscv64gc-unknown-linux-musl]' \
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'linker = "/usr/bin/clang"' \
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'rustflags = [' \
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' "-C", "link-arg=--ld-path=/usr/bin/mold",' \
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' "-C", "link-arg=--target=riscv64-unknown-linux-musl",' \
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']' \
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> .cargo/config.toml
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# Build std with:
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# - `-C embed-bitcode=yes` so downstream fat-LTO builds (e.g. vector with
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# `-C lto=fat`) can perform cross-crate LTO including std. Without this,
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# the linker fails with: "failed to get bitcode from object file for
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# LTO (Can't find section .llvmbc)".
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# - `-C target-feature=+crt-static` to match how consumers will be built.
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# Upstream rustc's tier-3 riscv64gc-unknown-linux-musl target spec is
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# missing `crt-static-default: true` (present on x86_64/aarch64 musl),
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# so we bake it in both here and in /usr/local/cargo/config.toml.
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# Mismatched std vs user crt-static can produce TLS/panic-runtime ABI
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# drift at link time.
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ENV CARGO_PROFILE_RELEASE_LTO=off
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RUN RUSTFLAGS="-C embed-bitcode=yes -C target-feature=+crt-static" \
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cargo build --release \
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--target riscv64gc-unknown-linux-musl \
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-Z build-std=std,panic_abort,core,alloc,proc_macro
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# Assemble a rustup-style sysroot fragment containing the freshly built std
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# rlibs PLUS the musl libc startup objects that rustc expects under
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# self-contained/. rustc looks for these under:
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# <sysroot>/lib/rustlib/<target>/lib/ (rlibs)
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# <sysroot>/lib/rustlib/<target>/lib/self-contained/ (Scrt1.o, crt1.o, ...)
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COPY --from=riscv64-musl-crt /crt-out/ /sysroot-out/lib/rustlib/riscv64gc-unknown-linux-musl/lib/self-contained/
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RUN SYSROOT_LIB=/sysroot-out/lib/rustlib/riscv64gc-unknown-linux-musl/lib && \
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mkdir -p "${SYSROOT_LIB}" && \
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cp /build-std/target/riscv64gc-unknown-linux-musl/release/deps/*.rlib "${SYSROOT_LIB}/" && \
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cp /build-std/target/riscv64gc-unknown-linux-musl/release/deps/*.rmeta "${SYSROOT_LIB}/" 2>/dev/null || true && \
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ls -la "${SYSROOT_LIB}" && \
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ls -la "${SYSROOT_LIB}/self-contained/"
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FROM rust:${RUST_VERSION}-alpine3.22 AS tools-target-base
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ARG RUST_VERSION
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ENV TARGETS="x86_64-unknown-linux-musl aarch64-unknown-linux-musl x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu riscv64gc-unknown-linux-gnu"
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RUN rustup target add ${TARGETS}
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# needed for cargo-chef and cargo-sbom, as well as many other compilations
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RUN apk add musl-dev linux-headers make clang llvm lld mold python3 git perl protoc
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# Stage the prebuilt riscv64gc-unknown-linux-musl std rlibs into a known
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# location, then install them into whichever host-arch toolchain dir rustup
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# actually created in this image. The target rlibs are host-independent, so
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# the same artifacts work regardless of the final image's host architecture.
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COPY --from=riscv64-std-builder /sysroot-out/ /tmp/riscv64-musl-sysroot/
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RUN HOST_TOOLCHAIN_DIR="$(ls -d /usr/local/rustup/toolchains/${RUST_VERSION}-* | head -n1)" && \
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echo "Installing riscv64-musl std into ${HOST_TOOLCHAIN_DIR}" && \
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cp -r /tmp/riscv64-musl-sysroot/lib "${HOST_TOOLCHAIN_DIR}/" && \
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rm -rf /tmp/riscv64-musl-sysroot && \
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ls -la "${HOST_TOOLCHAIN_DIR}/lib/rustlib/riscv64gc-unknown-linux-musl/lib/"
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ENV PATH=/usr/lib/llvm/bin:$PATH
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# export cross-compilation vars for both musl targets
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# export cross-compilation vars for all musl targets
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ENV CC_aarch64_unknown_linux_musl=clang \
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CFLAGS_aarch64_unknown_linux_musl="--target=aarch64-unknown-linux-musl" \
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AR_aarch64_unknown_linux_musl=llvm-ar \
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RANLIB_aarch64_unknown_linux_musl=llvm-ranlib \
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CC_x86_64_unknown_linux_musl=clang \
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CFLAGS_x86_64_unknown_linux_musl="--target=x86_64-unknown-linux-musl" \
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AR_x86_64_unknown_linux_musl=llvm-ar \
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RANLIB_x86_64_unknown_linux_musl=llvm-ranlib
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RANLIB_x86_64_unknown_linux_musl=llvm-ranlib \
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CC_riscv64gc_unknown_linux_musl=clang \
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CFLAGS_riscv64gc_unknown_linux_musl="--target=riscv64-unknown-linux-musl" \
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AR_riscv64gc_unknown_linux_musl=llvm-ar \
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RANLIB_riscv64gc_unknown_linux_musl=llvm-ranlib
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# copy the cargo plugins from the tools stage
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COPY --from=tools /cargo-cross /usr/local/cargo
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# we define target specific rustc flags for cross-compilation
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ADD config.toml /usr/local/cargo/
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FROM tools-target-base AS tools-target-amd64
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ENV CARGO_BUILD_TARGET="x86_64-unknown-linux-musl"
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FROM tools-target-base AS tools-target-arm64
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ENV CARGO_BUILD_TARGET="aarch64-unknown-linux-musl"
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FROM tools-target-base AS tools-target-riscv64
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ENV CARGO_BUILD_TARGET="riscv64gc-unknown-linux-gnu"
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FROM tools-target-$TARGETARCH AS tools-target
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RUN echo "Cargo target: $CARGO_BUILD_TARGET"
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# Per-target cross-compile config. Consumers that need to add their own
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# rustflags should either (a) not override RUSTFLAGS, or (b) ship their own
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# cargo config.toml that uses `[target.<triple>]` or `[target.'cfg(...)']`
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# rustflags so cargo merges them with the entries below (rustflags from the
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# RUSTFLAGS env var fully replaces config.toml rustflags and is discouraged).
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ADD config.toml /usr/local/cargo/

‎config.toml‎

Lines changed: 19 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -1,28 +1,29 @@
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[target.aarch64-unknown-linux-musl]
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linker = "/usr/bin/clang"
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rustflags = [
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"-C",
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"link-arg=--ld-path=/usr/bin/mold",
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"-C",
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"link-arg=--target=aarch64-unknown-linux-musl",
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"-C", "link-arg=--ld-path=/usr/bin/mold",
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"-C", "link-arg=--target=aarch64-unknown-linux-musl",
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"-C", "link-self-contained=yes",
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]
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[target.x86_64-unknown-linux-musl]
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linker = "/usr/bin/clang"
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rustflags = [
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"-C",
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"link-arg=--ld-path=/usr/bin/mold",
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"-C",
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"link-arg=--target=x86_64-unknown-linux-musl",
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"-C", "link-arg=--ld-path=/usr/bin/mold",
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"-C", "link-arg=--target=x86_64-unknown-linux-musl",
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"-C", "link-self-contained=yes",
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]
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# FIXME: riscv64 is not yet available in rust:1.80.1-alpine3.20
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# but both clang and mold support it. Also musl-dev is available in Alpine 3.20
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# [target.riscv64gc-unknown-linux-gnu]
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# linker = "/usr/bin/clang"
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# rustflags = [
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# "-C",
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# "link-arg=--ld-path=/usr/bin/mold",
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# "-C",
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# "link-arg=--target=riscv64-unknown-linux-musl",
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# ]
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[target.riscv64gc-unknown-linux-musl]
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linker = "/usr/bin/clang"
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# NOTE: riscv64gc-unknown-linux-musl is tier-3 in upstream rustc and its
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# target spec is missing `crt-static-default: true` (which x86_64/aarch64
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# musl have). Without `+crt-static` here, rustc picks the dynamic-unwind
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# path (`-lgcc_s` + `-pie`) instead of static (`-lunwind` + `-static`),
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# and the build fails because there is no riscv64 libgcc_s.so in the image.
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rustflags = [
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"-C", "link-arg=--ld-path=/usr/bin/mold",
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"-C", "link-arg=--target=riscv64-unknown-linux-musl",
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"-C", "link-self-contained=yes",
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"-C", "target-feature=+crt-static",
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]

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