fortrangoingonforty/armfortas / c7a292f

+#[test]

+fn allocatable_rank2_assign_from_transpose_uses_column_major_stride() {

+    // F2018 §10.1.5: allocatable LHS = transpose(reshape(...)) reallocates

+    // dest with source's shape and copies the data. afs_assign_allocatable

+    // used to set dest.dims[i].stride = 1 across the board, but the

+    // descriptor convention is that stride encodes per-dim *memory step*

+    // in column-major order — see afs_create_section's matching note.

+    // With stride=(1,1) on a 3x3 contiguous block, any subsequent path

+    // that walked the descriptor (e.g. ALLOCATE(target, source=A) inside

+    // a call where A is the assumed-shape dummy) produced overlapping

+    // byte offsets and corrupted the copy. Surfaced as wrong eigenvalue

+    // matrices in stdlib's eigvals/eig clusters.

+    let src = write_program(

+        r#"

+program p

+  implicit none

+  real, allocatable :: A(:,:)

+  A = transpose(reshape([2.0, 8.0, 4.0, 1.0, 3.0, 5.0, 9.0, 5.0, -2.0], [3,3]))

+  call check(A)

+contains

+  subroutine check(a)

+    real, intent(in), target :: a(:,:)

+    real, allocatable :: amat(:,:)

+    allocate(amat(3,3), source=a)

+    if (abs(amat(1,1) - 2.0) > 1.0e-6) error stop 1

+    if (abs(amat(2,1) - 1.0) > 1.0e-6) error stop 2

+    if (abs(amat(3,1) - 9.0) > 1.0e-6) error stop 3

+    if (abs(amat(1,2) - 8.0) > 1.0e-6) error stop 4

+    if (abs(amat(2,2) - 3.0) > 1.0e-6) error stop 5

+    if (abs(amat(3,2) - 5.0) > 1.0e-6) error stop 6

+    if (abs(amat(1,3) - 4.0) > 1.0e-6) error stop 7

+    if (abs(amat(2,3) - 5.0) > 1.0e-6) error stop 8

+    if (abs(amat(3,3) - (-2.0)) > 1.0e-6) error stop 9

+    print *, 'ok'

+  end subroutine

+end program

+"#,

+        "f90",

+    );

+    let out = unique_path("rank2_assign_transpose_stride", "bin");

+    let compile = Command::new(compiler("armfortas"))

+        .args([src.to_str().unwrap(), "-o", out.to_str().unwrap()])

+        .output()

+        .expect("rank2-stride compile failed");

+    assert!(

+        compile.status.success(),

+        "should compile: {}",

+        String::from_utf8_lossy(&compile.stderr)

+    );

+    let run = Command::new(&out).output().expect("run failed");

+    assert!(

+        run.status.success(),

+        "rank-2 allocatable = transpose() produced wrong values: status={:?} stderr={}",

+        run.status,

+        String::from_utf8_lossy(&run.stderr)

+    );

+    assert!(

+        String::from_utf8_lossy(&run.stdout).contains("ok"),

+        "expected 'ok': {}",

+        String::from_utf8_lossy(&run.stdout)

+    );

+    let _ = std::fs::remove_file(&out);

+    let _ = std::fs::remove_file(&src);

+}

+