manual c function interop

README.md

@@ -8,6 +8,25 @@ odin build . -out:brolang
 /tmp/prototype
 ```
 
+Bodyless `c func` declarations bind exact external symbols and require concrete
+types:
+
+```bro
+foreign_add :: c func(a, b i32) i32
+```
+
+Additional native inputs and libraries are passed to the final `zig cc`
+invocation in command-line order:
+
+```sh
+./brolang examples/interop/manual -o /tmp/manual \
+  --link examples/interop/manual/native.c
+```
+
+`--link` accepts C sources, object files, and direct library paths.
+`--library-path <dir>` becomes `-L<dir>`, and `--library <name>` becomes
+`-l<name>`.
+
 Compilation phases are isolated under `compiler/`:
 
 ```text
@@ -41,6 +60,8 @@ Current prototype features:
 - Directory packages with merged declarations and file-local relative imports
 - Qualified imported globals and functions with package-aware symbol mangling
 - Demand-monomorphized Brolang and C-ABI functions
+- Bodyless concrete C function declarations with exact external symbol names
+- Ordered linking of additional C sources, objects, and libraries
 - Checked signed addition
 - Static, eager runtime, and deferred problematic globals
 - Runtime diagnostics followed by `llvm.trap`