From: Paul Thomas <pault@gcc.gnu.org>
Date: Sat, 6 Dec 2025 07:54:39 +0000 (+0000)
Subject: Fortran: ALLOCATE with array-valued MOLD expression fails [PR122669]
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e48b0e8c048d2f101d14475affe4b8222f64dbb6;p=thirdparty%2Fgcc.git

Fortran: ALLOCATE with array-valued MOLD expression fails [PR122669]

2025-12-06  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/122669
	* resolve.cc (resolve_allocate_deallocate): Mold expressions
	with an array reference and a constant size must be resolved
	for each allocate object.

gcc/testsuite
	PR fortran/122669
	* gfortran.dg/pdt_73.f03: New test.
---

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 8e076c66bed..db6b52f3076 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -9799,8 +9799,10 @@ done_errmsg:
       /* Resolving the expr3 in the loop over all objects to allocate would
 	 execute loop invariant code for each loop item.  Therefore do it just
 	 once here.  */
+      mpz_t nelem;
       if (code->expr3 && code->expr3->mold
-	  && code->expr3->ts.type == BT_DERIVED)
+	  && code->expr3->ts.type == BT_DERIVED
+	  && !(code->expr3->ref && gfc_array_size (code->expr3, &nelem)))
 	{
 	  /* Default initialization via MOLD (non-polymorphic).  */
 	  gfc_expr *rhs = gfc_default_initializer (&code->expr3->ts);
diff --git a/gcc/testsuite/gfortran.dg/pdt_73.f03 b/gcc/testsuite/gfortran.dg/pdt_73.f03
new file mode 100644
index 00000000000..63a92342a67
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pdt_73.f03
@@ -0,0 +1,18 @@
+! { dg-do compile }
+!
+! Tests the fix for pr122669, which falied with the error below.
+!
+! Contributed by Damian Rouson  <damian@archaeologic.codes>
+!
+  implicit none
+  type tensor_t
+    real, allocatable :: values_
+  end type
+  type(tensor_t) :: random_inputs(1)
+  type(tensor_t), allocatable :: outputs(:)
+
+  random_inputs = [tensor_t(1.0)]
+  allocate(outputs, mold=random_inputs) ! Error: Array specification or array-valued
+                                        ! SOURCE= expression required in ALLOCATE statement at (1)
+  print *, size(outputs)
+end