Make the cdylib no_std

.github/workflows/checks.yaml

@@ -255,61 +255,6 @@ jobs:
   #           fi
   #           RUST_BACKTRACE=1 cargo fuzz run --no-default-features --features="$features" $target -- -max_total_time=10
   #         done
-  #
-  # link-c-dynamic-library:
-  #   name: dynamic library
-  #   strategy:
-  #     matrix:
-  #       include:
-  #         - target: x86_64-unknown-linux-gnu
-  #       features:
-  #         - ''
-  #   runs-on: ubuntu-latest
-  #   steps:
-  #     - name: Checkout sources
-  #       uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
-  #       with:
-  #         persist-credentials: false
-  #         submodules: true
-  #     - name: Install rust toolchain
-  #       uses: dtolnay/rust-toolchain@be73d7920c329f220ce78e0234b8f96b7ae60248
-  #       with:
-  #         toolchain: stable
-  #         targets: ${{matrix.target}}
-  #     - name: "cdylib: default settings"
-  #       working-directory: libz-rs-sys-cdylib
-  #       env:
-  #         LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
-  #       run: |
-  #         cargo build --release --target ${{matrix.target}}
-  #         cc -o zpipe zpipe.c target/${{matrix.target}}/release/deps/libz_rs.so
-  #         ./zpipe < Cargo.toml | ./zpipe -d > out.txt
-  #         cmp -s Cargo.toml out.txt
-  #     - name: "cdylib: rust-allocator"
-  #       env:
-  #         LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
-  #       working-directory: libz-rs-sys-cdylib
-  #       run: |
-  #         cargo build --release --target ${{matrix.target}} --no-default-features --features="rust-allocator"
-  #         cc -o zpipe zpipe.c target/${{matrix.target}}/release/deps/libz_rs.so
-  #         ./zpipe < Cargo.toml | ./zpipe -d > out.txt
-  #         cmp -s Cargo.toml out.txt
-  #     - name: "cdylib: no_std"
-  #       env:
-  #         LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
-  #       working-directory: libz-rs-sys-cdylib
-  #       run: |
-  #         cargo build --release --target ${{matrix.target}} --no-default-features
-  #         cc -o zpipe_no_std zpipe_no_std.c target/${{matrix.target}}/release/deps/libz_rs.so
-  #         ./zpipe_no_std < Cargo.toml | ./zpipe_no_std -d > out.txt
-  #         cmp -s Cargo.toml out.txt
-  #     - name: "cdylib: custom-prefix"
-  #       working-directory: libz-rs-sys-cdylib
-  #       env:
-  #         LIBZ_RS_SYS_PREFIX: "MY_CUSTOM_PREFIX_"
-  #       run: |
-  #         cargo build --release --target ${{matrix.target}} --features=custom-prefix
-  #         objdump -tT target/${{matrix.target}}/release/deps/libz_rs.so | grep -q "MY_CUSTOM_PREFIX_uncompress" || (echo "symbol not found!" && exit 1)
 
   wasm32:
     name: "wasm32"
@@ -401,16 +346,7 @@ jobs:
           cc -o bzpipe bzpipe.c target/${{matrix.target}}/release/deps/libbz2_rs.so -I ../
           ./bzpipe < Cargo.toml | ./bzpipe -d > out.txt
           cmp -s Cargo.toml out.txt
-      - name: "cdylib: rust-allocator"
-        env:
-          LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
-        working-directory: libbzip2-rs-sys-cdylib
-        run: |
-          cargo build --release --target ${{matrix.target}} --no-default-features --features="rust-allocator"
-          cc -o bzpipe bzpipe.c target/${{matrix.target}}/release/deps/libbz2_rs.so -I ../
-          ./bzpipe < Cargo.toml | ./bzpipe -d > out.txt
-          cmp -s Cargo.toml out.txt
-      - name: "cdylib: no_std"
+      - name: "cdylib: no stdio"
         env:
           LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
         working-directory: libbzip2-rs-sys-cdylib
@@ -424,7 +360,7 @@ jobs:
           LD_LIBRARY_PATH: "target/${{matrix.target}}/release/deps"
         working-directory: libbzip2-rs-sys-cdylib
         run: |
-          cargo build --release --target ${{matrix.target}} --no-default-features --features="c-allocator"
+          cargo build --release --target ${{matrix.target}} --no-default-features
           cc -o bzpipe bzpipe.c target/${{matrix.target}}/release/deps/libbz2_rs.so -I ../
           ./bzpipe < Cargo.toml | ./bzpipe -d > out.txt
           cmp -s Cargo.toml out.txt

libbzip2-rs-sys-cdylib/Cargo.toml

@@ -12,17 +12,18 @@ rust-version = "1.82" # MSRV
 
 [lib]
 name = "bz2_rs" # turns into e.g. `libbz2_rs.so`
-crate-type=["cdylib"]
+crate-type = ["cdylib"]
+test = false
 
 [features]
-default = ["c-allocator", "libbzip2-rs-sys/stdio",  "libbzip2-rs-sys/std"] # when used as a cdylib crate, use the c allocator
-c-allocator = ["libbzip2-rs-sys/c-allocator"] # by default, use malloc/free for memory allocation
-rust-allocator = ["libbzip2-rs-sys/rust-allocator", "libbzip2-rs-sys/std"] # by default, use the rust global alloctor for memory allocation
+default = ["stdio"]
+stdio = ["libbzip2-rs-sys/stdio"]
 custom-prefix = ["libbzip2-rs-sys/custom-prefix"] # use the LIBBZIP2_RS_SYS_PREFIX to prefix all exported symbols
 capi = []
 
 [dependencies]
-libbzip2-rs-sys = { version = "0.0.0", path = "../libbzip2-rs-sys", default-features = false }
+libbzip2-rs-sys = { version = "0.0.0", path = "../libbzip2-rs-sys", default-features = false, features = ["c-allocator"] }
+libc = "0.2"
 
 [package.metadata.capi.library]
 version = "1.0.9" # the bzip2 api version we match
@@ -34,3 +35,10 @@ enabled = false
 [package.metadata.capi.pkg_config]
 name = "libbz2_rs"
 filename = "libbz2_rs"
+
+# no_std requires panic=abort
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"

libbzip2-rs-sys-cdylib/bzpipe.c

@@ -6,6 +6,7 @@
 
 extern void bz_internal_error(int errcode) {
     fprintf(stderr, "bzip2 hit internal error code: %d\n", errcode);
+    exit(1);
 }
 
 #ifdef NO_STD

libbzip2-rs-sys-cdylib/src/lib.rs

@@ -1,3 +1,48 @@
+#![no_std]
+
 extern crate libbzip2_rs_sys;
 
+use core::panic::PanicInfo;
 pub use libbzip2_rs_sys::*;
+
+#[cfg(feature = "stdio")]
+struct StderrWritter;
+
+#[cfg(feature = "stdio")]
+impl core::fmt::Write for StderrWritter {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        use core::ffi::c_void;
+        use libc::write;
+
+        unsafe {
+            write(2, s.as_ptr() as *const c_void, s.len());
+        }
+        Ok(())
+    }
+}
+
+#[panic_handler]
+fn panic_handler(_info: &PanicInfo) -> ! {
+    #[cfg(feature = "stdio")]
+    {
+        use core::fmt::Write;
+        use libc::exit;
+
+        let _ = StderrWritter.write_str("libbzip2-rs: internal error:\n");
+        let _ = StderrWritter.write_fmt(format_args!("{}", _info.message()));
+
+        unsafe {
+            exit(3);
+        }
+    }
+
+    #[cfg(not(feature = "stdio"))]
+    {
+        extern "C" {
+            fn bz_internal_error(errcode: core::ffi::c_int);
+        }
+
+        unsafe { bz_internal_error(-1) }
+        loop {}
+    }
+}

libbzip2-rs-sys/Cargo.toml

@@ -4,7 +4,7 @@ readme = "README.md"
 edition.workspace = true
 
 [features]
-default = ["std", "c-allocator", "stdio"]
+default = ["std", "stdio"]
 c-allocator = ["dep:libc"] # use a malloc-based C allocator (rust is picked over c if both are configured)
 rust-allocator = [] # use the rust global allocator (rust is picked over c if both are configured)
 std = ["rust-allocator"]

libbzip2-rs-sys/src/lib.rs

@@ -84,37 +84,40 @@
 // --- assert failure logic
 
 macro_rules! assert_h {
-    ($condition:expr, $errcode:expr) => {{
-        #[cfg(feature = "stdio")]
+    ($condition:expr, $errcode:expr) => {
         if !$condition {
-            #[cfg(feature = "std")]
-            std::eprint!("{}", $crate::AssertFail($errcode));
-            #[cfg(feature = "std")]
-            std::process::exit(3);
-
-            #[cfg(not(feature = "std"))]
-            panic!("{}", $crate::AssertFail($errcode));
-        }
-
-        #[cfg(not(feature = "stdio"))]
-        if !$condition {
-            $crate::no_stdio_internal_error($errcode)
+            $crate::handle_assert_failure($errcode)
         }
-    }};
+    };
 }
 
-#[cfg(not(feature = "stdio"))]
-pub(crate) fn no_stdio_internal_error(errcode: c_int) {
-    extern "C" {
-        fn bz_internal_error(errcode: c_int);
+#[cold]
+fn handle_assert_failure(errcode: c_int) -> ! {
+    #[cfg(feature = "stdio")]
+    {
+        #[cfg(feature = "std")]
+        std::eprint!("{}", AssertFail(errcode));
+        #[cfg(feature = "std")]
+        std::process::exit(3);
+
+        #[cfg(not(feature = "std"))]
+        panic!("{}", AssertFail(errcode));
     }
 
-    unsafe { bz_internal_error(errcode) }
+    #[cfg(not(feature = "stdio"))]
+    {
+        extern "C" {
+            fn bz_internal_error(errcode: c_int);
+        }
+
+        unsafe { bz_internal_error(errcode) }
+        loop {}
+    }
 }
 
-pub(crate) use assert_h;
+use assert_h;
 
-pub(crate) struct AssertFail(i32);
+struct AssertFail(i32);
 
 impl core::fmt::Display for AssertFail {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {