[gcc r11-10284] Fortran: error recovery while simplifying intrinsic UNPACK [PR107054]

[Harald Anlauf <anlauf@gcc.gnu.org>]

https://gcc.gnu.org/g:c4f53f59aaa208f6c7aff0a8b4fb1950b1dc75a0

commit r11-10284-gc4f53f59aaa208f6c7aff0a8b4fb1950b1dc75a0
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Tue Sep 27 20:54:28 2022 +0200

    Fortran: error recovery while simplifying intrinsic UNPACK [PR107054]
    
    gcc/fortran/ChangeLog:
    
            PR fortran/107054
            * simplify.c (gfc_simplify_unpack): Replace assert by condition
            that terminates simplification when there are not enough elements
            in the constructor of argument VECTOR.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/107054
            * gfortran.dg/pr107054.f90: New test.
    
    (cherry picked from commit 78bc6497fc61bbdacfb416ee0246a775360d9af6)

Diff:
---
 gcc/fortran/simplify.c                 | 13 ++++++++++---
 gcc/testsuite/gfortran.dg/pr107054.f90 | 13 +++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 3b033a6be92..f13a8e57c83 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -8409,9 +8409,16 @@ gfc_simplify_unpack (gfc_expr *vector, gfc_expr *mask, gfc_expr *field)
     {
       if (mask_ctor->expr->value.logical)
 	{
-	  gcc_assert (vector_ctor);
-	  e = gfc_copy_expr (vector_ctor->expr);
-	  vector_ctor = gfc_constructor_next (vector_ctor);
+	  if (vector_ctor)
+	    {
+	      e = gfc_copy_expr (vector_ctor->expr);
+	      vector_ctor = gfc_constructor_next (vector_ctor);
+	    }
+	  else
+	    {
+	      gfc_free_expr (result);
+	      return NULL;
+	    }
 	}
       else if (field->expr_type == EXPR_ARRAY)
 	e = gfc_copy_expr (field_ctor->expr);
diff --git a/gcc/testsuite/gfortran.dg/pr107054.f90 b/gcc/testsuite/gfortran.dg/pr107054.f90
new file mode 100644
index 00000000000..bbfe646beba
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107054.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! PR fortran/107054 - ICE in gfc_simplify_unpack
+! Contributed by G.Steinmetz
+
+program p
+  type t
+     integer :: n = 0
+  end type
+  type(t), parameter :: a(4) = t(2)
+  type(t), parameter :: b(4) = reshape(a,[2]) ! { dg-error "Different shape" }
+  type(t), parameter :: c(2) = pack(b,[.false.,.true.,.false.,.true.]) ! { dg-error "Different shape" }
+  type(t), parameter :: d(4) = unpack(c,[.false.,.true.,.false.,.true.],a)
+end