separate guest import and export code

Cargo.toml

@@ -12,8 +12,7 @@ CLI tool to generate bindings for WIT documents and the component model.
 
 [workspace]
 members = [
-  "crates/test-rust-wasm",
-]
+  "crates/test-rust-wasm","crates/cpp/tests/native_strings/rust-host/rust_native_host_lib","crates/cpp/tests/native_strings/rust-host/rust_app"]
 resolver = "2"
 
 [workspace.package]

crates/cpp/Cargo.toml

@@ -9,6 +9,7 @@ description = """
 C++ guest and host binding generator for WIT and the component model.
 """
 
+
 [lib]
 doctest = false
 test = false

crates/cpp/tests/native_strings/Makefile

@@ -1,30 +1,36 @@
-CXXFLAGS=-g -O0 -I../../helper-types
+CXXFLAGS=-g -O0 -I../../helper-types -I../../cpp_host -I../../guest --std=c++17
 WIT_BINDGEN=../../../../target/debug/wit-bindgen
 
-all: libstrings.so app-strings
+all: libstrings.so cpp-app-strings rust-app-strings
 
-libstrings.so: the_world.pie.o guest.pie.o
-	$(CXX) $(CXXFLAGS) -shared -o $@ $^ -Wl,--version-script=guest.lds
+libstrings.so:
+	cd guest && make $@
 
-%.pie.o: %.cpp
-	$(CXX) $(CXXFLAGS) -fPIE -o $@ -c $^
+cpp-app-strings: ./cpp_host/the_world_native.o main.o ./cpp_host/guest_imported_fns.o
+	$(CXX) $(CXXFLAGS) -o $@ $^ -g -L./guest -lstrings
 
-app-strings: the_world_native.o main.o
-	$(CXX) $(CXXFLAGS) -o $@ $^ -L. -lstrings
+rust-app-strings:  main.o
+	$(CXX) $(CXXFLAGS) -o $@ $^ -g -L/mnt/sda2/pradeep/wasm/RND/math_fns/target/debug -lstrings
+
+
+the_world_native.o:
+	cd cpp_host && make $@
 
 bindgen: wit/strings.wit
 	$(WIT_BINDGEN) cpp wit --wasm64 --format
 	$(WIT_BINDGEN) cpp wit --wasm64 --format --direct
 	cd rust/src ; ../../$(WIT_BINDGEN) rust ../../wit --wasm64
 
-guest.wasm: the_world.cpp guest.cpp
+guest.wasm: the_world.cpp guest_1.cpp
 	/opt/wasi-sdk/bin/clang++ -o $@ $^ $(CXXFLAGS) 
 
-guest_release.wasm: the_world.cpp guest.cpp
+guest_release.wasm: the_world.cpp guest_1.cpp
 	/opt/wasi-sdk/bin/clang++ -o $@ $^ $(CXXFLAGS) -g0 -O3
 
 clean:
-	-rm *.o libstrings.so app-strings
+	-rm *.o app-strings
+	cd guest && make clean
+	cd cpp_host && make clean
 
 run:
 	LD_LIBRARY_PATH=. ./app-strings

crates/cpp/tests/native_strings/README.md

@@ -0,0 +1,50 @@
+# Native string example
+
+In this example, there is a guest, a native host (cpp_host) and an application.
+The `guest + native host` together form the actual `guest` code, which exports some APIs.
+Now the application which is `host`, will use the guest exported calls.
+The application/host also imports some calls, those are part of the `guest_imported_functions.cpp`
+
+The directory strucutre is as below:
+```
+├── cpp_host (Native host code)
+├── guest    (Guest code)
+├── guest_imported_fns.cpp ( host application imported calls)
+├── main.cpp (Application)
+└── wit (Wit file that is used for generating the code)
+
+```
+
+# Call-graph for a function
+
+This is how the example works, call graph for the function `A` (communication between the guest_1 and guest_2 using the mesh/native host code)
+
+guest_1->exports::foo::foo::strings::A(a){native host export call}->fooX3AfooX2FstringsX23a(){native host export binding(lifting)}
+-> exports::foo::foo::strings::A(wit::string &&x){guest_1 export implementation}
+-> foo::foo::strings::A(std::string_view x){guest import call}->fooX3AfooX2FstringsX00a() {native host import binding(lowering)}
+-> foo::foo::strings::A(std::string_view x) { guest import functions implementation}
+
+# Building the rust native string app
+Here is the rust based native string application source code tree
+```
+├── rust_app (Application that uses the native rust code)
+│   ├── Cargo.toml
+│   └── src
+│       └── main.rs
+└── rust_native_host_lib (Rust native rust code as library)
+    ├── Cargo.toml
+    └── src
+        ├── generated.rs
+        ├── guest_imported_fns.rs
+        ├── lib.rs
+        ├── native_imports.rs
+        ├── the_native_imports.rs
+        ├── the_world_native.rs
+        └── the_world.rs
+```
+to build and run the application run the command
+
+```shell
+cargo run -p rust_app`
+```
+

crates/cpp/tests/native_strings/cpp_host/Makefile

@@ -0,0 +1,14 @@
+CXXFLAGS=-g -O0 -I../../../helper-types --std=c++17
+WIT_BINDGEN=../../../../target/debug/wit-bindgen
+
+all: the_world_native.o guest_imported_fns.o
+
+the_world_native.o:
+	$(CXX) $(CXXFLAGS) -fPIE -o $@ -c the_world_native.cpp
+
+guest_imported_fns.o:
+	$(CXX) $(CXXFLAGS) -fPIE -o $@ -c guest_imported_fns.cpp
+
+
+clean:
+	-rm *.o

crates/cpp/tests/native_strings/cpp_host/guest_imported_fns.cpp

@@ -0,0 +1,20 @@
+#include "./the_world_cpp_native.h"
+#include <iostream>
+
+using namespace std;
+
+void foo::foo::strings::A(std::string_view x)
+{
+    std::cout << x << std::endl;
+}
+wit::string foo::foo::strings::B()
+{
+    wit::string b = wit::string::from_view(std::string_view("hello B"));
+    return b;
+}
+wit::string foo::foo::strings::C(std::string_view a, std::string_view b)
+{
+    std::cout << a << '|' << b << std::endl;
+    wit::string c = wit::string::from_view(std::string_view("hello C"));
+    return c;
+}

crates/cpp/tests/native_strings/the_world_native.cpp → crates/cpp/tests/native_strings/cpp_host/the_world_native.cpp

@@ -15,7 +15,7 @@ fooX3AfooX2FstringsX23c(uint8_t *, size_t, uint8_t *, size_t);
 extern "C" __attribute__((import_module("cabi_post_foo:foo/strings")))
 __attribute__((import_name("c"))) void
 cabi_post_fooX3AfooX2FstringsX23c(uint8_t *);
-extern "C" void fooX3AfooX2FstringsX00a(uint8_t *arg0, size_t arg1) {
+extern "C" void fooX3AfooX2FstringsX00a(uint8_t *arg0, size_t arg1) { 
   auto len0 = arg1;
 
   foo::foo::strings::A(std::string_view((char const *)(arg0), len0));
@@ -44,10 +44,10 @@ extern "C" void fooX3AfooX2FstringsX00c(uint8_t *arg0, size_t arg1,
   *((size_t *)(arg4 + 8)) = len3;
   *((uint8_t **)(arg4 + 0)) = ptr3;
 }
-void exports::foo::foo::strings::A(wit::string x) {
+void exports::foo::foo::strings::A(wit::string x) { 
   auto const &vec0 = x;
   auto ptr0 = vec0.data();
-  auto len0 = vec0.size();
+  auto len0 = vec0.size();  
   fooX3AfooX2FstringsX23a(ptr0, len0);
 }
 wit::guest_owned<std::string_view> exports::foo::foo::strings::B() {

crates/cpp/tests/native_strings/guest/Makefile

@@ -0,0 +1,35 @@
+CXXFLAGS=-g -O0 -I../../../helper-types --std=c++17
+WIT_BINDGEN=../../../../target/debug/wit-bindgen
+
+all: libstrings.so
+
+libstrings.so: the_world.pie.o guest.pie.o
+	$(CXX) $(CXXFLAGS) -shared -o $@ $^ -Wl,--version-script=guest.lds
+
+%.pie.o: %.cpp
+	$(CXX) $(CXXFLAGS) -fPIE -o $@ -c $^
+
+bindgen: wit/strings.wit
+	$(WIT_BINDGEN) cpp wit --wasm64 --format
+	cd cpp_host
+	$(WIT_BINDGEN) cpp wit --wasm64 --format --direct
+	cd -
+	cd rust/src ; ../../$(WIT_BINDGEN) rust ../../wit --wasm64
+
+guest.wasm: the_world.cpp guest.cpp
+	/opt/wasi-sdk/bin/clang++ -o $@ $^ $(CXXFLAGS)
+
+guest_release.wasm: the_world.cpp guest.cpp
+	/opt/wasi-sdk/bin/clang++ -o $@ $^ $(CXXFLAGS) -g0 -O3
+
+clean:
+	-rm *.o libstrings.so app-strings
+
+run:
+	LD_LIBRARY_PATH=. ./app-strings
+
+valgrind:
+	LD_LIBRARY_PATH=. valgrind ./app-strings
+
+w2c2_guest.c: guest_release.wasm
+	w2c2 $^ $@

crates/cpp/tests/native_strings/guest.cpp → crates/cpp/tests/native_strings/guest/guest.cpp

@@ -1,13 +1,16 @@
 #include "the_world_cpp.h"
 
-void exports::foo::foo::strings::A(wit::string &&x) {
+void exports::foo::foo::strings::A(wit::string &&x)
+{
     ::foo::foo::strings::A(x.get_view());
 }
 
-wit::string exports::foo::foo::strings::B() {
+wit::string exports::foo::foo::strings::B()
+{
     return ::foo::foo::strings::B();
 }
 
-wit::string exports::foo::foo::strings::C(wit::string &&x, wit::string &&b) {
+wit::string exports::foo::foo::strings::C(wit::string &&x, wit::string &&b)
+{
     return ::foo::foo::strings::C(x.get_view(), b.get_view());
 }

crates/cpp/tests/native_strings/the_world.cpp → crates/cpp/tests/native_strings/guest/the_world.cpp

@@ -34,7 +34,7 @@ fooX3AfooX2FstringsX00b(uint8_t *);
 extern "C" __attribute__((import_module("foo:foo/strings")))
 __attribute__((import_name("c"))) void
 fooX3AfooX2FstringsX00c(uint8_t *, size_t, uint8_t *, size_t, uint8_t *);
-void foo::foo::strings::A(std::string_view x) {
+void foo::foo::strings::A(std::string_view x) {  
   auto const &vec0 = x;
   auto ptr0 = (uint8_t *)(vec0.data());
   auto len0 = (size_t)(vec0.size());
@@ -63,9 +63,8 @@ wit::string foo::foo::strings::C(std::string_view a, std::string_view b) {
   return wit::string((char const *)(*((uint8_t **)(ptr2 + 0))), len3);
 }
 extern "C" __attribute__((__export_name__("foo:foo/strings#a"))) void
-fooX3AfooX2FstringsX23a(uint8_t *arg0, size_t arg1) {
-  auto len0 = arg1;
-
+fooX3AfooX2FstringsX23a(uint8_t *arg0, size_t arg1) { 
+  auto len0 = arg1; 
   exports::foo::foo::strings::A(wit::string((char const *)(arg0), len0));
 }
 extern "C" __attribute__((__export_name__("foo:foo/strings#b"))) uint8_t *

crates/cpp/tests/native_strings/main.cpp

@@ -1,20 +1,7 @@
 
-#include "the_world_cpp_native.h"
+#include "./cpp_host/the_world_cpp_native.h"
 #include <iostream>
 
-void foo::foo::strings::A(std::string_view x) {
-    std::cout << x << std::endl;
-}
-wit::string foo::foo::strings::B() {
-    wit::string b = wit::string::from_view(std::string_view("hello B"));
-    return b;
-}
-wit::string foo::foo::strings::C(std::string_view a, std::string_view b) {
-    std::cout << a << '|' << b << std::endl;
-    wit::string c = wit::string::from_view(std::string_view("hello C"));
-    return c;
-}
-
 int main() {
     wit::string a = wit::string::from_view(std::string_view("hello A"));
     exports::foo::foo::strings::A(a);

crates/cpp/tests/native_strings/rust-host/rust_app/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "rust_app"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rust_native_host_lib = {path ="../rust_native_host_lib"}

crates/cpp/tests/native_strings/rust-host/rust_app/src/main.rs

@@ -0,0 +1,14 @@
+use rust_native_host_lib::the_world_native::exports::foo::foo::strings::{a, b, c};
+
+fn main() {
+    a("hello a".into());
+    {
+        let b = b();
+        println!("{}", b);
+    }
+
+    let c1 = "hello C1";
+    let c2 = "hello C2";
+    let c = c(c1.into(), c2.into());
+    println!("{}",c);
+}

crates/cpp/tests/native_strings/rust-host/rust_native_host_lib/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "rust_native_host_lib"
+version = "0.1.0"
+edition.workspace = true
+
+[dependencies]

crates/cpp/tests/native_strings/rust/src/lib.rs → crates/cpp/tests/native_strings/rust-host/rust_native_host_lib/src/generated.rs

@@ -1,26 +1,24 @@
 use std::alloc::Layout;
 
-use the_world::exports::foo::foo::strings::Guest;
-
-mod the_world;
-
+use crate::__export_foo_foo_strings_cabi;
+use crate::the_world::exports::foo::foo::strings::Guest;
 struct MyWorld;
 
 impl Guest for MyWorld {
-    fn a(x: String,) {
-        the_world::foo::foo::strings::a(&x);
+    fn a(x: String) {
+        crate::the_world::foo::foo::strings::a(&x);
     }
 
     fn b() -> String {
-        the_world::foo::foo::strings::b()
+        crate::the_world::foo::foo::strings::b()
     }
 
-    fn c(a: String,b: String,) -> String {
-        the_world::foo::foo::strings::c(&a, &b)
+    fn c(a: String, b: String) -> String {
+        crate::the_world::foo::foo::strings::c(&a, &b)
     }
 }
 
-the_world::export!(MyWorld with_types_in the_world);
+__export_foo_foo_strings_cabi!(MyWorld with_types_in crate::the_world::exports::foo::foo::strings);
 
 // the crate wit-bindgen-rt doesn't work on native
 #[no_mangle]
@@ -43,7 +41,7 @@ pub unsafe extern "C" fn cabi_realloc(
         std::alloc::realloc(old_ptr, layout, new_len)
     };
     if ptr.is_null() {
-            unreachable!();
+        unreachable!();
     }
     return ptr;
 }

crates/cpp/tests/native_strings/rust-host/rust_native_host_lib/src/guest_imported_fns.rs

@@ -0,0 +1,20 @@
+pub mod foo {
+    pub mod foo {
+        pub mod strings {
+
+            pub fn a(a: String) {
+                println!("{a}");
+            }
+            pub fn b() -> String {
+                let s = String::from("hello B");
+                s
+            }
+
+            pub fn c(a: String, b: String) -> String {
+                println!("guest imported: {} | {}", a, b);
+                let s = String::from("hello C");
+                s
+            }
+        }
+    }
+}

crates/cpp/tests/native_strings/rust-host/rust_native_host_lib/src/lib.rs

@@ -0,0 +1,5 @@
+mod generated;
+pub mod guest_imported_fns;
+mod native_imports;
+mod the_world;
+pub mod the_world_native;