rust: enable bindings to be built without existing cmake build dir

Author: NickeZ

.gitattributes

@@ -1 +1,2 @@
-/py/bitbox02/bitbox02/generated/* linguist-generated=true
+/py/bitbox02/bitbox02/generated/** linguist-generated=true
+/src/rust/vendor/** linguist-generated=true

src/CMakeLists.txt

@@ -306,6 +306,14 @@ add_custom_target(rust-bindgen
   )
 add_dependencies(rust-bindgen generate-protobufs)
 
+# A custom target to export the list of includes for rust tooling (RA, clippy)
+add_custom_command(OUTPUT rust-bindgen.flags
+  COMMAND
+    ${CMAKE_COMMAND} -E echo ${RUST_INCLUDES} > rust-bindgen.flags
+)
+add_custom_target(rust-bindgen-includes DEPENDS rust-bindgen.flags)
+add_dependencies(rust-bindgen-includes generate-protobufs)
+
 
 # Test rust crates that contain business logic. Avoid testing crates that depend on hardware.
 if(NOT CMAKE_CROSSCOMPILING)

src/rust/Cargo.lock

@@ -35,3 +35,9 @@ The bottom-most layer are bindings generated from C header files:
 
 We generate one header file `rust.h` and ever product specific function is `#ifdeffed` with
 `RUST_PRODUCT_*` macro.
+
+
+# rust-analyzer / clippy
+
+To be able to run static analyzers you'll need nanopb to work and libclang to be available on the
+host machine.

src/rust/README.md

@@ -22,3 +22,7 @@ license = "Apache-2.0"
 
 [dependencies]
 util = {path = "../util"}
+
+[build-dependencies]
+# We chose leonard-llc/temp-dir over rust-lang/tempdir because it has fewer dependencies
+temp-dir = "0.1"

src/rust/bitbox02-sys/Cargo.toml

@@ -0,0 +1,41 @@
+use std::process::Command;
+use std::fs::File;
+use std::io::prelude::*;
+use temp_dir::TempDir;
+
+fn main() {
+    let path_to_bindings = if let Ok(cmake_dir) = std::env::var("CMAKE_CURRENT_BINARY_DIR") {
+        // if we are being invoked from CMAKE, the bindings are here:
+        format!("{}/rust", cmake_dir)
+    } else {
+        let bitbox02_sys_dir = std::env::var("CARGO_MANIFEST_DIR").unwrap();
+        let cmake_dir = format!("{}/../../../", bitbox02_sys_dir);
+
+        // generate list of includes using CMake
+        let tempdir = TempDir::with_prefix("bitbox02").unwrap();
+        let tempdir = tempdir.path().to_str().unwrap();
+        let _ = Command::new("cmake").arg(&cmake_dir).current_dir(&tempdir).output().unwrap();
+        let _ = Command::new("make").arg("rust-bindgen-includes").current_dir(&tempdir).output().unwrap();
+        let mut includes_file = File::open(format!("{}/src/rust-bindgen.flags", tempdir)).unwrap();
+        let mut includes = String::new();
+        includes_file.read_to_string(&mut includes).unwrap();
+        let includes:Vec<&str> = includes.trim().split_ascii_whitespace().collect();
+        let target = std::env::var("TARGET").unwrap();
+        let mut flags = vec!["-target", &target, "-DTESTING=1"];
+        flags.extend(&includes);
+
+        // generate bindings
+        let outdir = std::env::var("OUT_DIR").unwrap();
+        let generate_bindings = format!("{}/scripts/generate-bindings.sh", cmake_dir);
+        let bindings = format!("{}/bindings.rs", outdir);
+        let wrapper = format!("{}/wrapper.h", bitbox02_sys_dir);
+        let _ = Command::new(&generate_bindings)
+            .args(&[&bindings, &wrapper])
+            .args(&flags)
+            .output()
+            .unwrap();
+
+        outdir
+    };
+    println!("cargo:rustc-env=BINDINGS={}/bindings.rs", path_to_bindings);
+}

src/rust/bitbox02-sys/build.rs

@@ -17,10 +17,7 @@
 #![allow(non_upper_case_globals)]
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
+#![allow(clippy::all)]
 
 // include our generated bindings
-include!(concat!(
-    env!("CMAKE_CURRENT_BINARY_DIR"),
-    "/rust",
-    "/bindings.rs"
-));
+include!(env!("BINDINGS"));

src/rust/bitbox02-sys/src/lib.rs

@@ -1,24 +1,26 @@
 fn main() {
     #[cfg(feature = "testing")]
     {
-        let cmake_dir = std::env::var("CMAKE_CURRENT_BINARY_DIR").unwrap();
-        println!("cargo:rustc-link-search={}/../lib", cmake_dir);
-        // c and rust code merged :O
-        println!("cargo:rustc-link-lib=bitbox_merged");
-        println!(
-            "cargo:rerun-if-changed={}/../lib/libbitbox_merged.a",
-            cmake_dir
-        );
+        // CMAKE_CURRENT_BINARY_DIR is required for building tests
+        if let Ok(cmake_dir) = std::env::var("CMAKE_CURRENT_BINARY_DIR") {
+            println!("cargo:rustc-link-search={}/../lib", cmake_dir);
+            // c and rust code merged :O
+            println!("cargo:rustc-link-lib=bitbox_merged");
+            println!(
+                "cargo:rerun-if-changed={}/../lib/libbitbox_merged.a",
+                cmake_dir
+            );
 
-        // external libs
-        println!("cargo:rustc-link-lib=wallycore");
-        println!("cargo:rustc-link-lib=secp256k1");
-        println!("cargo:rustc-link-lib=base32");
-        println!("cargo:rustc-link-lib=ctaes");
-        println!("cargo:rustc-link-lib=fatfs");
-        println!("cargo:rustc-link-lib=sd-mock");
+            // external libs
+            println!("cargo:rustc-link-lib=wallycore");
+            println!("cargo:rustc-link-lib=secp256k1");
+            println!("cargo:rustc-link-lib=base32");
+            println!("cargo:rustc-link-lib=ctaes");
+            println!("cargo:rustc-link-lib=fatfs");
+            println!("cargo:rustc-link-lib=sd-mock");
 
-        // system libs
-        println!("cargo:rustc-link-lib=cmocka");
+            // system libs
+            println!("cargo:rustc-link-lib=cmocka");
+        }
     }
 }