WIP: autocxx

.github/workflows/ci.yml → .github/workflows/CI.yml

@@ -21,7 +21,8 @@ jobs:
           rustup component add clippy
       - run: cargo clippy -p mfem-sys --features bundled -- -D warnings
       - run: cargo build -p mfem-sys --features bundled
-      - run: cargo run -p mfem-sys --features bundled --example ex1 -- --mesh crates/mfem-cpp/mfem/data/escher.mesh
+      - run: cargo run -p mfem-sys --features bundled --example ex1_sys -- --mesh data/square.mesh
+      - run: cargo run -p mfem --features bundled --example ex1 -- --mesh data/square.mesh
 
   build-osx:
     runs-on: macos-latest
@@ -39,7 +40,8 @@ jobs:
           rustup update ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
       - run: cargo build -p mfem-sys --features bundled
-      - run: cargo run -p mfem-sys --features bundled --example ex1 -- --mesh crates/mfem-cpp/mfem/data/escher.mesh
+      - run: cargo run -p mfem-sys --features bundled --example ex1_sys -- --mesh data/square.mesh
+      - run: cargo run -p mfem --features bundled --example ex1 -- --mesh data/square.mesh
 
   build-windows:
     runs-on: windows-latest
@@ -56,7 +58,8 @@ jobs:
           rustup update ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
       - run: cargo build -p mfem-sys --features bundled
-      - run: cargo run -p mfem-sys --features bundled --example ex1 --verbose -- --mesh crates/mfem-cpp/mfem/data/escher.mesh
+      - run: cargo run -p mfem-sys --features bundled --example ex1_sys -- --mesh data/square.mesh
+      - run: cargo run -p mfem --features bundled --example ex1 -- --mesh data/square.mesh
 
   fmt:
     name: Rust fmt

.gitignore

@@ -1,3 +1,5 @@
 target/
 Cargo.lock
 .DS_Store
+/*.mesh
+/*.gf

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "crates/mfem-cpp/mfem"]
 	path = crates/mfem-cpp/mfem
-	url = git@github.com:mfem/mfem.git
+	url = https://github.com/mfem/mfem.git

crates/mfem-cpp/Cargo.toml

@@ -4,7 +4,7 @@ description = "Static build of MFEM for use as a Rust dependency"
 readme = "README.md"
 authors = ["Mate Kovacs <mkovaxx@gmail.com>"]
 license = "MIT"
-version = "0.3.0+mfem-4.7.0"
+version = "0.3.0+mfem-4.8-rc0"
 edition = "2021"
 repository = "https://github.com/mkovaxx/mfem-rs"
 
@@ -13,8 +13,5 @@ repository = "https://github.com/mkovaxx/mfem-rs"
 [build-dependencies]
 cmake = "0.1"
 
-# Adding an empty workspace table so `mfem-cpp` doesn't believe
-# it's in the parent workspace. This crate is excluded from
-# the top-level workspace because it takes quite awhile to
-# build and the crate doesn't change very often.
-#[workspace]
+[features]
+precision-f32 = []

crates/mfem-cpp/build.rs

@@ -2,11 +2,15 @@ const LIB_DIR: &str = "lib";
 const INCLUDE_DIR: &str = "include";
 
 fn main() {
-    let dst = cmake::Config::new("mfem")
-        .define("BUILD_LIBRARY_TYPE", "Static")
+    let mut conf = cmake::Config::new("mfem");
+    conf.define("BUILD_LIBRARY_TYPE", "Static")
         .define("INSTALL_DIR_LIB", LIB_DIR)
-        .define("INSTALL_DIR_INCLUDE", INCLUDE_DIR)
-        .build();
+        .define("INSTALL_DIR_INCLUDE", INCLUDE_DIR);
+    #[cfg(not(feature = "precision-f32"))]
+    conf.define("MFEM_PRECISION", "double");
+    #[cfg(feature = "precision-f32")]
+    conf.define("MFEM_PRECISION", "single");
+    let dst = conf.build();
 
     println!("cargo:rustc-env=MFEM_PATH={}", dst.display());
 }

crates/mfem-sys/Cargo.toml

@@ -7,18 +7,21 @@ license = "MIT"
 version = "0.2.0"
 edition = "2021"
 repository = "https://github.com/mkovaxx/mfem-rs"
+rust-version = "1.77"
 
 [dependencies]
-cxx = "1"
+cxx = "1.0.157"
+autocxx = "0.28"
 
 [build-dependencies]
 cmake = "0.1"
-cxx-build = "1"
+autocxx-build = "0.28"
 mfem-cpp = { version = "0.3", path = "../mfem-cpp", optional = true }
 semver = "1.0.22"
 
 [features]
 bundled = ["mfem-cpp"]
+bundled-f32 = ["mfem-cpp/precision-f32"]
 
 [dev-dependencies]
 clap = { version = "4.5.4", features = ["derive"] }

crates/mfem-sys/MFEM/CMakeLists.txt

@@ -1,15 +1,13 @@
-cmake_minimum_required (VERSION 3.5 FATAL_ERROR)
+cmake_minimum_required (VERSION 3.12 FATAL_ERROR)
 project (MfemPackageConfig)
 
 set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE "BOTH" CACHE PATH "")
 
 message(STATUS "Looking for mfem ...")
-set(MFEM_DIR "" CACHE PATH "Path to the MFEM build or install prefix.")
-if (MFEM_DIR)
-   find_package(mfem REQUIRED NAMES MFEM HINTS "${MFEM_DIR}"
-                "${MFEM_DIR}/lib/cmake/mfem" NO_DEFAULT_PATH)
-else()
-   find_package(mfem REQUIRED NAMES MFEM)
+find_package(MFEM REQUIRED CONFIG)
+
+if (NOT DEFINED MFEM_INCLUDE_DIRS)
+  set(MFEM_INCLUDE_DIRS "")
 endif()
 
 file (WRITE ${CMAKE_BINARY_DIR}/mfem_info.txt
@@ -18,6 +16,6 @@ file (WRITE ${CMAKE_BINARY_DIR}/mfem_info.txt
       "INCLUDE_DIRS=${MFEM_INCLUDE_DIRS}\n"
       "LIBRARY_DIR=${MFEM_LIBRARY_DIR}\n"
       "CXX_FLAGS=${MFEM_CXX_FLAGS}\n"
-)
+    )
 
 install (FILES ${CMAKE_BINARY_DIR}/mfem_info.txt TYPE DATA)

crates/mfem-sys/build.rs

@@ -1,49 +1,47 @@
-/// The list of used MFEM libraries which needs to be linked with.
 fn main() {
     let target = std::env::var("TARGET").expect("No TARGET environment variable defined");
     let is_windows = target.to_lowercase().contains("windows");
 
-    let mfem_config = MfemConfig::detect();
+    let mut mfem_config = MfemConfig::detect();
 
     println!(
         "cargo:rustc-link-search=native={}",
-        mfem_config.library_dir.to_str().unwrap()
+        mfem_config.library_dir.display()
     );
 
     for lib in mfem_config.mfem_libs {
-        #[cfg(feature = "bundled")]
-        println!("cargo:rustc-link-lib=static={lib}");
-        #[cfg(not(feature = "bundled"))]
         println!("cargo:rustc-link-lib={lib}");
     }
 
     if is_windows {
         println!("cargo:rustc-link-lib=dylib=user32");
     }
 
-    let mut build = cxx_build::bridge("src/lib.rs");
-
-    if let "windows" = std::env::consts::OS {
-        let current = std::env::current_dir().unwrap();
-        build.include(current.parent().unwrap());
-    }
-
+    mfem_config.include_dirs.push("src".into());
+    mfem_config.include_dirs.push("include".into()); // for cxx.
+    let mut build = autocxx_build::Builder::new("src/lib.rs", &mfem_config.include_dirs)
+        .build()
+        .expect("autocxx builder");
     build
-        .cpp(true)
-        .std("c++14")
-        .flag_if_supported("-w")
-        .includes(mfem_config.include_dirs)
-        .include("include");
+        .flag_if_supported("-std=c++14")
+        .flag_if_supported("-O3")
+        .flag_if_supported("-w");
     for f in mfem_config.cxx_flags {
         build.flag_if_supported(&f);
     }
+    if let "windows" = std::env::consts::OS {
+        let current = std::env::current_dir().unwrap();
+        build.include(current.parent().unwrap());
+    }
 
-    build.compile("wrapper");
+    build.compile("mfem-sys");
 
-    println!("cargo:rustc-link-lib=static=wrapper");
+    println!("cargo:rustc-link-lib=static=mfem-sys");
 
     println!("cargo:rerun-if-changed=src/lib.rs");
-    println!("cargo:rerun-if-changed=include/wrapper.hpp");
+    println!("cargo:rerun-if-changed=src/ffi_autocxx.hpp");
+    println!("cargo:rerun-if-changed=src/ffi_cxx.hpp");
+    println!("cargo:rerun-if-changed=MFEM/CMakeLists.txt ");
 }
 
 #[derive(Debug)]
@@ -62,76 +60,71 @@ impl MfemConfig {
         // Pre-installed MFEM will be checked for compatibility using semver rules.
         let version_req = semver::VersionReq::parse(">=4.6").expect("Invalid version constraint");
 
-        println!("cargo:rerun-if-env-changed=DEP_MFEM_ROOT");
-
-        // Add path to bundled MFEM
-        #[cfg(feature = "bundled")]
+        #[cfg(any(feature = "bundled", feature = "bundled-f32"))]
         {
-            std::env::set_var("DEP_MFEM_ROOT", mfem_cpp::mfem_path().as_os_str());
+            // For the `register_dep` of `cmake` to set
+            // `CMAKE_PREFIX_PATH` to the right directory.
+            std::env::set_var("DEP_MFEM_ROOT", mfem_cpp::mfem_path().as_os_str())
         }
+        println!("cargo:rerun-if-env-changed=DEP_MFEM_ROOT");
 
         let dst =
             std::panic::catch_unwind(|| cmake::Config::new("MFEM").register_dep("mfem").build());
 
-        #[cfg(feature = "bundled")]
+        #[cfg(any(feature = "bundled", feature = "bundled-f32"))]
         let dst = dst.expect("Bundled MFEM not found.");
 
-        #[cfg(not(feature = "bundled"))]
-        let dst = dst.expect("Pre-installed MFEM not found. You can use `bundled` feature if you do not want to install MFEM system-wide.");
+        #[cfg(not(any(feature = "bundled", feature = "bundled-f32")))]
+        let dst = dst.expect("Pre-installed MFEM not found.  You can use MFEM_DIR to point to its location. Alternatively, you can use `bundled` feature if you do not want to install MFEM system-wide.");
 
         let cfg = std::fs::read_to_string(dst.join("share").join("mfem_info.txt"))
             .expect("Something went wrong when detecting MFEM.");
 
         let mut version: Option<semver::Version> = None;
-        let mut mfem_libs: Vec<String> = vec![];
-        let mut include_dirs: Vec<std::path::PathBuf> = vec![];
-        let mut library_dir: Option<std::path::PathBuf> = None;
-        let mut cxx_flags: Vec<String> = vec![];
+        let mut mfem_config = MfemConfig {
+            mfem_libs: vec![],
+            include_dirs: vec![],
+            library_dir: std::path::PathBuf::new(),
+            cxx_flags: vec![],
+        };
 
         for line in cfg.lines() {
             if let Some((var, val)) = line.split_once('=') {
                 match var {
                     // Keep in sync with "MFEM/CMakeLists.txt".
                     "VERSION" => version = semver::Version::parse(val).ok(),
                     "MFEM_LIBRARIES" => {
-                        for l in val.split(" ") {
-                            // FIXME: Right delim?
-                            mfem_libs.push(l.into());
+                        for l in val.split(";") {
+                            mfem_config.mfem_libs.push(l.into());
                         }
                     }
                     "INCLUDE_DIRS" => {
                         for d in val.split(";") {
-                            include_dirs.push(d.into());
+                            mfem_config.include_dirs.push(d.into());
                         }
                     }
-                    "LIBRARY_DIR" => library_dir = val.parse().ok(),
+                    "LIBRARY_DIR" => mfem_config.library_dir = val.into(),
                     "CXX_FLAGS" => {
                         for f in val.split(" ") {
-                            cxx_flags.push(f.into());
+                            mfem_config.cxx_flags.push(f.into());
                         }
                     }
                     _ => (),
                 }
             }
         }
 
-        if let (Some(version), Some(library_dir)) = (version, library_dir) {
+        if let Some(version) = version {
             if !version_req.matches(&version) {
-                #[cfg(feature = "bundled")]
+                #[cfg(any(feature = "bundled", feature = "bundled-f32"))]
                 panic!("Bundled MFEM found but version is not met (found {} but {} required). Please fix MFEM_VERSION in build script of `mfem-sys` crate or submodule mfem in `mfem-cpp` crate.",
                        version, version_req);
 
-                #[cfg(not(feature = "bundled"))]
+                #[cfg(not(any(feature = "bundled", feature = "bundled-f32")))]
                 panic!("Pre-installed MFEM found but version is not met (found {} but {} required). Please provide required version or use `bundled` feature.",
                        version, version_req);
             }
-
-            Self {
-                mfem_libs,
-                include_dirs,
-                library_dir,
-                cxx_flags,
-            }
+            mfem_config
         } else {
             panic!("MFEM found but something went wrong during configuration.");
         }