Link test for LAPACK routines written in Fortran

.github/workflows/openblas-src.yml

@@ -82,7 +82,7 @@ jobs:
     - uses: actions/checkout@v1
       with:
         submodules: 'recursive'
-    - name: Install GCC-Fortran by apt
+    - name: Install gfortran by apt
       run: |
         apt update
         apt install -y gfortran

openblas-src/build.rs

@@ -107,7 +107,20 @@ fn build() {
     } else {
         cfg.no_static = true;
     }
-    cfg.build(&output).unwrap();
+    let deliv = cfg.build(&output).unwrap();
+
+    for search_path in &deliv.make_conf.c_extra_libs.search_paths {
+        println!("cargo:rustc-link-search={}", search_path.display());
+    }
+    for lib in &deliv.make_conf.c_extra_libs.libs {
+        println!("cargo:rustc-link-lib={}", lib);
+    }
+    for search_path in &deliv.make_conf.f_extra_libs.search_paths {
+        println!("cargo:rustc-link-search={}", search_path.display());
+    }
+    for lib in &deliv.make_conf.f_extra_libs.libs {
+        println!("cargo:rustc-link-lib={}", lib);
+    }
     println!("cargo:rustc-link-search={}", output.display());
 }
 

openblas-src/tests/fortran_lapack.rs

@@ -0,0 +1,72 @@
+// FIXME This should be test also on Windows and macOS.
+//
+// However, we have several problems:
+//
+// - we cannot build Fortran part of OpenBLAS on windows-msvc platform
+//   because the absence of Fortran compiler
+//
+// - In macOS, we can get gfortran by `brew install gcc`,
+//   but it is too time-consuming to execute on CI.
+//   GitHub Actions's macOS instance says gfotran is "installed",
+//   but it is too fragile me to give up using it.
+//
+#![cfg(target_os = "linux")]
+
+extern crate openblas_src as _src;
+
+extern "C" {
+    fn dormbr_(
+        vect: *const u8,
+        side: *const u8,
+        trans: *const u8,
+        m: *const i32,
+        n: *const i32,
+        k: *const i32,
+        A: *const f64,
+        lda: *const i32,
+        tau: *const f64,
+        C: *mut f64,
+        ldc: *const i32,
+        work: *mut f64,
+        lwork: *const i32,
+        info: *mut i32,
+    );
+}
+
+// `dormbr_` is imported from reference LAPACK written in Fortran into OpenBLAS project.
+// This test will fail to link when OpenBLAS does not build Fortran part.
+#[test]
+fn test_link_lapack() {
+    let m = 1;
+    let n = 1;
+    let k = 1;
+    let vect = b'Q';
+    let side = b'L';
+    let trans = b'N';
+    let a = vec![0.0];
+    let lda = 1;
+    let mut c = vec![0.0];
+    let ldc = 1;
+    let tau = 0.0;
+    let mut work = vec![0.0];
+    let lwork = 1;
+    let mut info = 0;
+    unsafe {
+        dormbr_(
+            &vect,
+            &side,
+            &trans,
+            &m,
+            &n,
+            &k,
+            a.as_ptr(),
+            &lda,
+            &tau,
+            c.as_mut_ptr(),
+            &ldc,
+            work.as_mut_ptr(),
+            &lwork,
+            &mut info,
+        );
+    }
+}