first bits of a dynamc lib

Cargo.lock

@@ -591,6 +591,25 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "cbindgen"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51e3973b165dc0f435831a9e426de67e894de532754ff7a3f307c03ee5dec7dc"
+dependencies = [
+ "clap",
+ "heck",
+ "indexmap",
+ "log",
+ "proc-macro2",
+ "quote",
+ "serde",
+ "serde_json",
+ "syn",
+ "tempfile",
+ "toml",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.68"
@@ -3008,6 +3027,14 @@ dependencies = [
  "toml_edit",
 ]
 
+[[package]]
+name = "taskchampion-lib"
+version = "0.1.0"
+dependencies = [
+ "cbindgen",
+ "taskchampion",
+]
+
 [[package]]
 name = "taskchampion-sync-server"
 version = "0.4.1"

Cargo.toml

@@ -4,5 +4,6 @@ members = [
     "taskchampion",
     "cli",
     "sync-server",
-    "replica-server-tests"
+    "replica-server-tests",
+    "lib"
 ]

binding-tests/.gitignore

@@ -0,0 +1,2 @@
+*.o
+doctest

binding-tests/Makefile

@@ -0,0 +1,19 @@
+CXX=g++
+INC=-I ../lib
+LIB=-L ../target/debug
+RPATH=-Wl,-rpath,../target/debug 
+
+TESTS = uuid.cpp
+
+.PHONY: all test
+
+all: test
+
+test: doctest
+	@./doctest --no-version --no-intro
+
+%.o: %.cpp ../lib/taskchampion.h
+	$(CXX) $(INC) -c $< -o $@
+
+doctest: doctest.o $(subst .cpp,.o,$(TESTS))
+	$(CXX) $(LIB) $(RPATH) $< $(subst .cpp,.o,$(TESTS)) -ltaskchampion -o $@

binding-tests/doctest.cpp

@@ -0,0 +1,2 @@
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+#include "doctest.h"

binding-tests/uuid.cpp

@@ -0,0 +1,7 @@
+#include "doctest.h"
+#include "taskchampion.h"
+
+TEST_CASE("creating a UUID") {
+    StoragePtr *storage = storage_new_in_memory();
+    storage_free(storage);
+}

lib/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "taskchampion-lib"
+version = "0.1.0"
+edition = "2021"
+build = "build.rs"
+
+[lib]
+name = "taskchampion"
+crate-type = ["cdylib"]
+
+[dependencies]
+taskchampion = { path = "../taskchampion" }
+
+[build-dependencies]
+cbindgen = "0.20.0"

lib/Makefile

@@ -0,0 +1,2 @@
+taskchampion.h: cbindgen.toml ../target/debug/libtaskchampion.so
+	cbindgen --config cbindgen.toml --crate taskchampion-lib --output $@

lib/build.rs

@@ -0,0 +1,18 @@
+use cbindgen::*;
+
+use std::env;
+
+fn main() {
+    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+
+    Builder::new()
+        .with_crate(crate_dir)
+        .with_language(Language::C)
+        .with_config(Config {
+            cpp_compat: true,
+            ..Default::default()
+        })
+        .generate()
+        .expect("Unable to generate bindings")
+        .write_to_file("taskchampion.h");
+}

lib/src/lib.rs

@@ -0,0 +1 @@
+pub mod storage;

lib/src/storage.rs

@@ -0,0 +1,16 @@
+use taskchampion::{storage::Storage, StorageConfig};
+
+pub struct StoragePtr(Box<dyn Storage>);
+
+#[no_mangle]
+pub extern "C" fn storage_new_in_memory() -> *mut StoragePtr {
+    // TODO: this is a box containing a fat pointer
+    Box::into_raw(Box::new(StoragePtr(
+        StorageConfig::InMemory.into_storage().unwrap(),
+    )))
+}
+
+#[no_mangle]
+pub extern "C" fn storage_free(storage: *mut StoragePtr) {
+    drop(unsafe { Box::from_raw(storage) });
+}

lib/taskchampion.h

@@ -0,0 +1,15 @@
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <ostream>
+#include <new>
+
+struct StoragePtr;
+
+extern "C" {
+
+StoragePtr *storage_new_in_memory();
+
+void storage_free(StoragePtr *storage);
+
+} // extern "C"