Generate cxx binding in build.rs

native/src/base/Android.mk

@@ -15,6 +15,7 @@ LOCAL_SRC_FILES := \
     selinux.cpp \
     logging.cpp \
     stream.cpp \
+    base-rs.cpp \
     ../external/cxx-rs/src/cxx.cc
 include $(BUILD_STATIC_LIBRARY)
 

native/src/base/Cargo.toml

@@ -6,6 +6,9 @@ edition = "2021"
 [lib]
 path = "lib.rs"
 
+[build-dependencies]
+cxx-gen = { path = "../external/cxx-rs/gen/lib" }
+
 [dependencies]
 cxx = { path = "../external/cxx-rs" }
 libc = "0.2"

native/src/base/build.rs

@@ -0,0 +1,7 @@
+use crate::gen::gen_cxx_binding;
+
+mod gen;
+
+fn main() {
+    gen_cxx_binding("base-rs");
+}

native/src/base/gen.rs

@@ -0,0 +1,38 @@
+// This file hosts shared build script logic
+
+use std::fmt::Display;
+use std::fs::File;
+use std::io::Write;
+use std::process;
+
+use cxx_gen::Opt;
+
+trait ResultExt<T> {
+    fn ok_or_exit(self) -> T;
+}
+
+impl<T, E: Display> ResultExt<T> for Result<T, E> {
+    fn ok_or_exit(self) -> T {
+        match self {
+            Ok(r) => r,
+            Err(e) => {
+                eprintln!("error occurred: {}", e);
+                process::exit(1);
+            }
+        }
+    }
+}
+
+pub fn gen_cxx_binding(name: &str) {
+    println!("cargo:rerun-if-changed=lib.rs");
+    let opt = Opt::default();
+    let gen = cxx_gen::generate_header_and_cc_with_path("lib.rs", &opt);
+    {
+        let mut cpp = File::create(format!("{}.cpp", name)).unwrap();
+        cpp.write_all(gen.implementation.as_slice()).ok_or_exit();
+    }
+    {
+        let mut hpp = File::create(format!("{}.hpp", name)).unwrap();
+        hpp.write_all(gen.header.as_slice()).ok_or_exit();
+    }
+}

native/src/base/include/base.hpp

@@ -5,4 +5,4 @@
 #include "../files.hpp"
 #include "../misc.hpp"
 #include "../logging.hpp"
-#include <base-rs.hpp>
+#include "../base-rs.hpp"

native/src/base/logging.cpp

@@ -6,9 +6,6 @@
 #include <flags.h>
 #include <base.hpp>
 
-// Just need to include it somewhere
-#include <base-rs.cpp>
-
 using namespace std;
 
 static int fmt_and_log_with_rs(LogLevel level, const char *fmt, va_list ap) {

native/src/base/logging.hpp

@@ -3,8 +3,6 @@
 #include <cerrno>
 #include <cstdarg>
 
-#include <base-rs.hpp>
-
 void LOGD(const char *fmt, ...) __printflike(1, 2);
 void LOGI(const char *fmt, ...) __printflike(1, 2);
 void LOGW(const char *fmt, ...) __printflike(1, 2);

native/src/base/misc.hpp

@@ -7,8 +7,6 @@
 #include <bitset>
 #include <random>
 
-#include <base-rs.hpp>
-
 #define DISALLOW_COPY_AND_MOVE(clazz) \
 clazz(const clazz &) = delete; \
 clazz(clazz &&) = delete;

native/src/base/xwrap.hpp

@@ -5,7 +5,7 @@
 #include <poll.h>
 #include <fcntl.h>
 
-#include <base-rs.hpp>
+#include "base-rs.hpp"
 
 using rust::xpipe2;