* Re: [PATCH] Fix type of imported variable for arraydim.exp
2026-07-30 16:59 [PATCH] Fix type of imported variable for arraydim.exp Tom Tromey
@ 2026-07-31 12:01 ` Tom de Vries
2026-08-03 13:29 ` Tom Tromey
0 siblings, 1 reply; 3+ messages in thread
From: Tom de Vries @ 2026-07-31 12:01 UTC (permalink / raw)
To: Tom Tromey, gdb-patches
On 7/30/26 6:59 PM, Tom Tromey wrote:
> The test code for gdb.ada/arraydim.exp imports a variable using a
> dummy type. Then the test tries to print the type of this variable.
> This works ok with GCC, because the import is emitted as a
> declaration; but this fails with gnat-llvm, where a definition is
> emitted.
>
> This seems to be a test bug to me. This patch fixes the problem by
> using the correct type here.
Hi Tom,
thanks for fixing this.
Do I understand it correctly that there are two (independent) issues:
- decl vs def: fixed in arraydim.exp
- dummy type vs correct type: fixed in arraydim/foo.adb
?
Anyway, the changes in arraydim.exp look fine to me.
Given that it's Ada, I can't really comment on the changes in
arraydim/foo.adb.
I did wonder if the test-case still functioned as regression test after
these changes, so I reverse-applied commit 8a48ac9579f ("wrong dimension
found in ada-lang.c:ada_array_bound_from_type"):
...
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 3c6c9af488f..0f28ce65239 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -3360,7 +3360,7 @@ ada_index_type (struct type *type, int n, const
char *name)
static LONGEST
ada_array_bound_from_type (struct type *arr_type, int n, int which)
{
- struct type *type, *index_type_desc, *index_type;
+ struct type *type, *elt_type, *index_type_desc, *index_type;
int i;
gdb_assert (which == 0 || which == 1);
@@ -3376,6 +3376,10 @@ ada_array_bound_from_type (struct type *arr_type,
int n, int which)
else
type = arr_type;
+ elt_type = type;
+ for (i = n; i > 1; i--)
+ elt_type = type->target_type ();
+
if (type->is_fixed_instance ())
{
/* The array has already been fixed, so we do not need to
@@ -3393,14 +3397,7 @@ ada_array_bound_from_type (struct type *arr_type,
int n, int which)
index_type = to_fixed_range_type (index_type_desc->field (n -
1).type (),
NULL);
else
- {
- struct type *elt_type = check_typedef (type);
-
- for (i = 1; i < n; i++)
- elt_type = check_typedef (elt_type->target_type ());
-
- index_type = elt_type->index_type ();
- }
+ index_type = elt_type->index_type ();
return (which == 0
? ada_discrete_type_low_bound (index_type)
...
and managed to detect the regression with and without this patch.
Reviewed-By: Tom de Vries <tdevries@suse.de>
Thanks,
- Tom
> ---
> gdb/testsuite/gdb.ada/arraydim.exp | 7 ++++++-
> gdb/testsuite/gdb.ada/arraydim/foo.adb | 7 ++-----
> 2 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.ada/arraydim.exp b/gdb/testsuite/gdb.ada/arraydim.exp
> index 7b84a7af9b7..815a91ffa82 100644
> --- a/gdb/testsuite/gdb.ada/arraydim.exp
> +++ b/gdb/testsuite/gdb.ada/arraydim.exp
> @@ -52,8 +52,13 @@ gdb_test "print m'first(3)" " = 4"
> gdb_test "print m'last(3)" " = 6"
> gdb_test "print m'length(3)" " = 3"
>
> +# With GCC the test shows "int" as the element type, but with
> +# gnat-llvm it shows "integer"; both of these are reasonable enough so
> +# we accept either. The difference here is because GCC emits a
> +# declaration in the DWARF for foo.o, but gnat-llvm emits a
> +# definition.
> gdb_test "ptype global_3dim_for_gdb_testing" \
> - "array \\(0 \\.\\. 0, 0 \\.\\. 1, 0 \\.\\. 2\\) of int"
> + [quotemeta "array (0 .. 0, 0 .. 1, 0 .. 2) of @/(int|integer)/"]
>
> gdb_test "print global_3dim_for_gdb_testing'first" " = 0"
> gdb_test "print global_3dim_for_gdb_testing'last" " = 0"
> diff --git a/gdb/testsuite/gdb.ada/arraydim/foo.adb b/gdb/testsuite/gdb.ada/arraydim/foo.adb
> index 86204956d00..8da63e1af93 100644
> --- a/gdb/testsuite/gdb.ada/arraydim/foo.adb
> +++ b/gdb/testsuite/gdb.ada/arraydim/foo.adb
> @@ -18,11 +18,8 @@ procedure Foo is
> type Multi is array (1 .. 1, 2 .. 3, 4 .. 6) of Integer;
> M : Multi := (others => (others => (others => 0)));
>
> - -- Use a fake type for importing our C multi-dimensional array.
> - -- It's only to make sure the C unit gets linked in, regardless
> - -- of possible optimizations.
> - type Void_Star is access integer;
> - E : Void_Star;
> + type C_Multi is array (0 .. 0, 0 .. 1, 0 .. 2) of Integer;
> + E : C_Multi;
> pragma Import (C, E, "global_3dim_for_gdb_testing");
> begin
> Do_Nothing (M'Address); -- STOP
>
> base-commit: 6d1be0b90e837e4c82eaaf6f9e8c7da7227902e1
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