Add an example using c-gull and std::unwind::catch_unwind.

example-crates/c-gull-unwinding/.gitignore

@@ -0,0 +1,2 @@
+/target
+Cargo.lock

example-crates/c-gull-unwinding/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "c-gull-unwinding"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies.libc]
+path = "../../c-gull"
+default-features = false
+features = [
+    "take-charge",
+    "std",
+    "thread",
+    "call-main",
+    "malloc-via-crates",
+    "threadsafe-setenv"
+]
+package = "c-gull"
+
+# This is just an example crate, and not part of the c-ward workspace.
+[workspace]

example-crates/c-gull-unwinding/README.md

@@ -0,0 +1,6 @@
+This crate demonstrates the use of c-gull in "take-charge" mode, and includes
+unwinding panic support.
+
+It's the same as [c-gull-example], but it performs an unwind.
+
+[c-gull-example]: https://github.com/sunfishcode/c-ward/tree/main/example-crates/c-gull-example#readme

example-crates/c-gull-unwinding/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    // Pass -nostartfiles to the linker.
+    println!("cargo:rustc-link-arg=-nostartfiles");
+}

example-crates/c-gull-unwinding/src/main.rs

@@ -0,0 +1,19 @@
+//! A simple example using `std::panic::catch_unwind`.
+
+fn main() {
+    // Panic and catch it.
+    std::panic::catch_unwind(|| call_do_panic()).unwrap_err();
+
+    println!("Hello, world!");
+    unsafe {
+        libc::printf("Hello world using libc `printf`!\n\0".as_ptr().cast());
+    }
+}
+
+fn call_do_panic() {
+    do_panic()
+}
+
+fn do_panic() {
+    panic!("catch me!");
+}

example-crates/c-scape-unwinding/README.md

@@ -3,6 +3,6 @@ and `no_std`, and includes unwinding panic support.
 
 It's the same as [c-scape-example], but enables the "eh-personality" and
 "panic-handler" features instead of defining stub `#[panic_handler]` and
-`#[lang = "eh_personality"]` functions, and performs an unwind.
+`#[lang = "eh_personality"]` functions, and it performs an unwind.
 
 [c-scape-example]: https://github.com/sunfishcode/c-ward/tree/main/example-crates/c-scape-example#readme

tests/example_crates.rs

@@ -126,6 +126,18 @@ fn example_crate_c_scape_unwinding() {
     );
 }
 
+#[test]
+fn example_crate_c_gull_unwinding() {
+    test_crate(
+        "c-gull-unwinding",
+        &[],
+        &[("RUST_BACKTRACE", "0")],
+        "Hello, world!\nHello world using libc `printf`!\n",
+        "thread 'main' panicked at src/main.rs:18:5:\ncatch me!\nnote: run with `RUST_BACKTRACE=1` environment variable to display a backtrace\n",
+        None,
+    );
+}
+
 #[test]
 fn example_crate_dns() {
     test_crate(