[PATCH] Printing of Fortran arrays with dynamic elements

[PATCH] Printing of Fortran arrays with dynamic elements

[Tom Tromey]

This bug points out a case where a Fortran array has dynamic elements,
and each element must have its dynamic type resolved separately.

I took the test case directly from the bug, figuring it was ok as the
author is at AMD and has some tags in the repository already.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34276
---
 gdb/f-array-walker.h                          |  9 +++--
 .../gdb.fortran/dynamic-elements.exp          | 37 +++++++++++++++++++
 .../gdb.fortran/dynamic-elements.f90          | 34 +++++++++++++++++
 3 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100644 gdb/testsuite/gdb.fortran/dynamic-elements.exp
 create mode 100644 gdb/testsuite/gdb.fortran/dynamic-elements.f90

diff --git a/gdb/f-array-walker.h b/gdb/f-array-walker.h
index bb8cb0ca599..4392e54013b 100644
--- a/gdb/f-array-walker.h
+++ b/gdb/f-array-walker.h
@@ -267,13 +267,16 @@ class fortran_array_walker
 	  {
 	    LONGEST elt_off = offset + calc.index_offset (i);
 
-	    if (is_dynamic_type (elt_type))
+	    struct type *this_elt_type = elt_type;
+	    if (is_dynamic_type (this_elt_type))
 	      {
 		CORE_ADDR e_address = m_address + elt_off;
-		elt_type = resolve_dynamic_type (elt_type, {}, e_address);
+		this_elt_type = resolve_dynamic_type (this_elt_type, {},
+						      e_address);
 	      }
 
-	    m_impl.process_element (elt_type, elt_off, i, i == upperbound);
+	    m_impl.process_element (this_elt_type, elt_off, i,
+				    i == upperbound);
 	  }
       }
 
diff --git a/gdb/testsuite/gdb.fortran/dynamic-elements.exp b/gdb/testsuite/gdb.fortran/dynamic-elements.exp
new file mode 100644
index 00000000000..4a83ad09438
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/dynamic-elements.exp
@@ -0,0 +1,37 @@
+# Copyright 2026 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test where an array has elements of dynamic type, where each element
+# is different.
+
+require allow_fortran_tests
+
+standard_testfile .f90
+load_lib "fortran.exp"
+
+if {[prepare_for_testing "failed to prepare" ${testfile} ${srcfile} \
+	 {debug f90}]} {
+    return
+}
+
+if {![fortran_runto_main]} {
+    return
+}
+
+gdb_breakpoint [gdb_get_line_number "stop"]
+gdb_continue_to_breakpoint "stop"
+
+gdb_test "print keys" \
+    [quotemeta "@DECIMAL = (( f = (1, 2) ), ( f = (3, 4, 5) ))"]
diff --git a/gdb/testsuite/gdb.fortran/dynamic-elements.f90 b/gdb/testsuite/gdb.fortran/dynamic-elements.f90
new file mode 100644
index 00000000000..61a2b6edb3c
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/dynamic-elements.f90
@@ -0,0 +1,34 @@
+! Copyright 2026 Free Software Foundation, Inc.
+!
+! This program is free software; you can redistribute it and/or modify
+! it under the terms of the GNU General Public License as published by
+! the Free Software Foundation; either version 3 of the License, or
+! (at your option) any later version.
+!
+! This program is distributed in the hope that it will be useful,
+! but WITHOUT ANY WARRANTY; without even the implied warranty of
+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+! GNU General Public License for more details.
+!
+! You should have received a copy of the GNU General Public License
+! along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+program test
+  implicit none
+
+  type :: arr
+    integer, allocatable :: f (:)
+  end type
+
+  type(arr), dimension(2) :: keys
+  allocate (keys(1)%f(2))
+  allocate (keys(2)%f(3))
+  keys(1)%f(1) = 1
+  keys(1)%f(2) = 2
+  keys(2)%f(1) = 3
+  keys(2)%f(2) = 4
+  keys(2)%f(3) = 5
+  print *, keys(1)%f(1)         ! stop
+  print *, keys(2)%f(1)
+
+end program test
-- 
2.49.0

Re: [PATCH] Printing of Fortran arrays with dynamic elements

[Tom de Vries]

On 6/19/26 11:42 PM, Tom Tromey wrote:
> This bug points out a case where a Fortran array has dynamic elements,
> and each element must have its dynamic type resolved separately.
> 
> I took the test case directly from the bug, figuring it was ok as the
> author is at AMD and has some tags in the repository already.
> 

LGTM.

Reviewed-By: Tom de Vries <tdevries@suse.de>

Thanks,
- Tom

> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34276
> ---
>   gdb/f-array-walker.h                          |  9 +++--
>   .../gdb.fortran/dynamic-elements.exp          | 37 +++++++++++++++++++
>   .../gdb.fortran/dynamic-elements.f90          | 34 +++++++++++++++++
>   3 files changed, 77 insertions(+), 3 deletions(-)
>   create mode 100644 gdb/testsuite/gdb.fortran/dynamic-elements.exp
>   create mode 100644 gdb/testsuite/gdb.fortran/dynamic-elements.f90
> 
> diff --git a/gdb/f-array-walker.h b/gdb/f-array-walker.h
> index bb8cb0ca599..4392e54013b 100644
> --- a/gdb/f-array-walker.h
> +++ b/gdb/f-array-walker.h
> @@ -267,13 +267,16 @@ class fortran_array_walker
>   	  {
>   	    LONGEST elt_off = offset + calc.index_offset (i);
>   
> -	    if (is_dynamic_type (elt_type))
> +	    struct type *this_elt_type = elt_type;
> +	    if (is_dynamic_type (this_elt_type))
>   	      {
>   		CORE_ADDR e_address = m_address + elt_off;
> -		elt_type = resolve_dynamic_type (elt_type, {}, e_address);
> +		this_elt_type = resolve_dynamic_type (this_elt_type, {},
> +						      e_address);
>   	      }
>   
> -	    m_impl.process_element (elt_type, elt_off, i, i == upperbound);
> +	    m_impl.process_element (this_elt_type, elt_off, i,
> +				    i == upperbound);
>   	  }
>         }
>   
> diff --git a/gdb/testsuite/gdb.fortran/dynamic-elements.exp b/gdb/testsuite/gdb.fortran/dynamic-elements.exp
> new file mode 100644
> index 00000000000..4a83ad09438
> --- /dev/null
> +++ b/gdb/testsuite/gdb.fortran/dynamic-elements.exp
> @@ -0,0 +1,37 @@
> +# Copyright 2026 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +# Test where an array has elements of dynamic type, where each element
> +# is different.
> +
> +require allow_fortran_tests
> +
> +standard_testfile .f90
> +load_lib "fortran.exp"
> +
> +if {[prepare_for_testing "failed to prepare" ${testfile} ${srcfile} \
> +	 {debug f90}]} {
> +    return
> +}
> +
> +if {![fortran_runto_main]} {
> +    return
> +}
> +
> +gdb_breakpoint [gdb_get_line_number "stop"]
> +gdb_continue_to_breakpoint "stop"
> +
> +gdb_test "print keys" \
> +    [quotemeta "@DECIMAL = (( f = (1, 2) ), ( f = (3, 4, 5) ))"]
> diff --git a/gdb/testsuite/gdb.fortran/dynamic-elements.f90 b/gdb/testsuite/gdb.fortran/dynamic-elements.f90
> new file mode 100644
> index 00000000000..61a2b6edb3c
> --- /dev/null
> +++ b/gdb/testsuite/gdb.fortran/dynamic-elements.f90
> @@ -0,0 +1,34 @@
> +! Copyright 2026 Free Software Foundation, Inc.
> +!
> +! This program is free software; you can redistribute it and/or modify
> +! it under the terms of the GNU General Public License as published by
> +! the Free Software Foundation; either version 3 of the License, or
> +! (at your option) any later version.
> +!
> +! This program is distributed in the hope that it will be useful,
> +! but WITHOUT ANY WARRANTY; without even the implied warranty of
> +! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +! GNU General Public License for more details.
> +!
> +! You should have received a copy of the GNU General Public License
> +! along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +program test
> +  implicit none
> +
> +  type :: arr
> +    integer, allocatable :: f (:)
> +  end type
> +
> +  type(arr), dimension(2) :: keys
> +  allocate (keys(1)%f(2))
> +  allocate (keys(2)%f(3))
> +  keys(1)%f(1) = 1
> +  keys(1)%f(2) = 2
> +  keys(2)%f(1) = 3
> +  keys(2)%f(2) = 4
> +  keys(2)%f(3) = 5
> +  print *, keys(1)%f(1)         ! stop
> +  print *, keys(2)%f(1)
> +
> +end program test

Re: [PATCH] Printing of Fortran arrays with dynamic elements

[Tom Tromey]

>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:

Tom> On 6/19/26 11:42 PM, Tom Tromey wrote:
>> This bug points out a case where a Fortran array has dynamic elements,
>> and each element must have its dynamic type resolved separately.
>> I took the test case directly from the bug, figuring it was ok as
>> the
>> author is at AMD and has some tags in the repository already.
>> 

Tom> LGTM.

Tom> Reviewed-By: Tom de Vries <tdevries@suse.de>

I'm checking this in.

Tom