Add a component model example

This adds the 'Hello World' example from here[0]. The runtime is in Rust
and the component is in C.

This requires some new tools

  - https://github.com/bytecodealliance/wit-bindgen
  - https://github.com/bytecodealliance/wasm-tools

You can use the pre-built packages, once downloaded and untar'd, edit

  rust/hello_world/component/Makefile

and adjust the paths for the above tools.

To build the component with make you may need to specify where the WASI
sysroot is

  $ make WASI_SYSROOT=/path/to/wasi-sysroot

[0]: <https://docs.rs/wasmtime/latest/wasmtime/component/macro.bindgen.html>

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/rust/hello_world/component/my-component.c b/rust/hello_world/component/my-component.c
new file mode 100644
index 0000000..fe09975
--- /dev/null
+++ b/rust/hello_world/component/my-component.c
@@ -0,0 +1,14 @@
+/*
+ * my-component.c
+ */
+
+#include "hello_world.h"
+
+void hello_world_greet(void)
+{
+	hello_world_string_t my_string;
+
+	hello_world_string_set(&my_string, "Hello, world!");
+
+	hello_world_name(&my_string);
+}