[PATCH] [gdb] Add unit test for iterator_range

[PATCH] [gdb] Add unit test for iterator_range

[Tom de Vries]

I noticed iterator_range doesn't have a selftest.  I found int_array_iterator
in filtered_iterator-selftests.c, and decided to use that as iterator.

Factor out int-array-iterator.h out of filtered_iterator-selftests.c, and use
it in new unit test iterator-range-selftests.c.
---
 gdb/Makefile.in                             |   1 +
 gdb/unittests/filtered_iterator-selftests.c |  75 +--------------
 gdb/unittests/int-array-iterator.h          | 101 ++++++++++++++++++++
 gdb/unittests/iterator-range-selftests.c    | 100 +++++++++++++++++++
 4 files changed, 203 insertions(+), 74 deletions(-)
 create mode 100644 gdb/unittests/int-array-iterator.h
 create mode 100644 gdb/unittests/iterator-range-selftests.c

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 1acf99e3346..e38ba95eebd 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -472,6 +472,7 @@ SELFTESTS_SRCS = \
 	unittests/gdb_tilde_expand-selftests.c \
 	unittests/gmp-utils-selftests.c \
 	unittests/intrusive_list-selftests.c \
+	unittests/iterator-range-selftests.c \
 	unittests/lookup_name_info-selftests.c \
 	unittests/memory-map-selftests.c \
 	unittests/memrange-selftests.c \
diff --git a/gdb/unittests/filtered_iterator-selftests.c b/gdb/unittests/filtered_iterator-selftests.c
index 17408b2798b..f40c2a1c4ab 100644
--- a/gdb/unittests/filtered_iterator-selftests.c
+++ b/gdb/unittests/filtered_iterator-selftests.c
@@ -19,83 +19,10 @@
 
 #include "gdbsupport/selftest.h"
 #include "gdbsupport/filtered-iterator.h"
-
-#include <iterator>
+#include "int-array-iterator.h"
 
 namespace selftests {
 
-/* An iterator class that iterates on integer arrays.  */
-
-struct int_array_iterator
-{
-  using value_type = int;
-  using reference = int &;
-  using pointer = int *;
-  using iterator_category = std::forward_iterator_tag;
-  using difference_type = int;
-
-  /* Create an iterator that points at the first element of an integer
-     array at ARRAY of size SIZE.  */
-  int_array_iterator (int *array, size_t size)
-    : m_array (array), m_size (size)
-  {}
-
-  /* Create a past-the-end iterator.  */
-  int_array_iterator ()
-    : m_array (nullptr), m_size (0)
-  {}
-
-  bool operator== (const int_array_iterator &other) const
-  {
-    /* If both are past-the-end, they are equal.  */
-    if (m_array == nullptr && other.m_array == nullptr)
-      return true;
-
-    /* If just one of them is past-the-end, they are not equal.  */
-    if (m_array == nullptr || other.m_array == nullptr)
-      return false;
-
-    /* If they are both not past-the-end, make sure they iterate on the
-       same array (we shouldn't compare iterators that iterate on different
-       things).  */
-    SELF_CHECK (m_array == other.m_array);
-
-    /* They are equal if they have the same current index.  */
-    return m_cur_idx == other.m_cur_idx;
-  }
-
-  bool operator!= (const int_array_iterator &other) const
-  {
-    return !(*this == other);
-  }
-
-  void operator++ ()
-  {
-    /* Make sure nothing tries to increment a past the end iterator. */
-    SELF_CHECK (m_cur_idx < m_size);
-
-    m_cur_idx++;
-
-    /* Mark the iterator as "past-the-end" if we have reached the end.  */
-    if (m_cur_idx == m_size)
-      m_array = nullptr;
-  }
-
-  int operator* () const
-  {
-    /* Make sure nothing tries to dereference a past the end iterator.  */
-    SELF_CHECK (m_cur_idx < m_size);
-
-    return m_array[m_cur_idx];
-  }
-
-private:
-  /* A nullptr value in M_ARRAY indicates a past-the-end iterator.  */
-  int *m_array;
-  size_t m_size;
-  size_t m_cur_idx = 0;
-};
-
 /* Filter to only keep the even numbers.  */
 
 struct even_numbers_only
diff --git a/gdb/unittests/int-array-iterator.h b/gdb/unittests/int-array-iterator.h
new file mode 100644
index 00000000000..03b0e038501
--- /dev/null
+++ b/gdb/unittests/int-array-iterator.h
@@ -0,0 +1,101 @@
+/* An iterator class that iterates on integer arrays.
+
+   Copyright (C) 2019-2026 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#ifndef GDB_UNITTESTS_INT_ARRAY_ITERATOR_H
+#define GDB_UNITTESTS_INT_ARRAY_ITERATOR_H
+
+#include "gdbsupport/selftest.h"
+
+#include <iterator>
+
+namespace selftests {
+
+struct int_array_iterator
+{
+  using value_type = int;
+  using reference = int &;
+  using pointer = int *;
+  using iterator_category = std::forward_iterator_tag;
+  using difference_type = int;
+
+  /* Create an iterator that points at the first element of an integer
+     array at ARRAY of size SIZE.  */
+  int_array_iterator (int *array, size_t size)
+    : m_array (array), m_size (size)
+  {}
+
+  /* Create a past-the-end iterator.  */
+  int_array_iterator ()
+    : m_array (nullptr), m_size (0)
+  {}
+
+  bool operator== (const int_array_iterator &other) const
+  {
+    /* If both are past-the-end, they are equal.  */
+    if (m_array == nullptr && other.m_array == nullptr)
+      return true;
+
+    /* If just one of them is past-the-end, they are not equal.  */
+    if (m_array == nullptr || other.m_array == nullptr)
+      return false;
+
+    /* If they are both not past-the-end, make sure they iterate on the
+       same array (we shouldn't compare iterators that iterate on different
+       things).  */
+    SELF_CHECK (m_array == other.m_array);
+
+    /* They are equal if they have the same current index.  */
+    return m_cur_idx == other.m_cur_idx;
+  }
+
+  bool operator!= (const int_array_iterator &other) const
+  {
+    return !(*this == other);
+  }
+
+  void operator++ ()
+  {
+    /* Make sure nothing tries to increment a past the end iterator.  */
+    SELF_CHECK (m_cur_idx < m_size);
+
+    m_cur_idx++;
+
+    /* Mark the iterator as "past-the-end" if we have reached the end.  */
+    if (m_cur_idx == m_size)
+      m_array = nullptr;
+  }
+
+  int operator* () const
+  {
+    /* Make sure nothing tries to dereference a past the end iterator.  */
+    SELF_CHECK (m_cur_idx < m_size);
+
+    return m_array[m_cur_idx];
+  }
+
+private:
+  /* A nullptr value in M_ARRAY indicates a past-the-end iterator.  */
+  int *m_array;
+  size_t m_size;
+  size_t m_cur_idx = 0;
+};
+
+} /* namespace selftests */
+
+#endif /* GDB_UNITTESTS_INT_ARRAY_ITERATOR_H */
diff --git a/gdb/unittests/iterator-range-selftests.c b/gdb/unittests/iterator-range-selftests.c
new file mode 100644
index 00000000000..a05531d95e0
--- /dev/null
+++ b/gdb/unittests/iterator-range-selftests.c
@@ -0,0 +1,100 @@
+/* Self tests for the iterator_range class.
+
+   Copyright (C) 2026 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#include "gdbsupport/selftest.h"
+#include "gdbsupport/iterator-range.h"
+#include "int-array-iterator.h"
+
+namespace selftests {
+
+using int_array_iterator_range = iterator_range<int_array_iterator>;
+
+static void
+test_iterator_range_1 (int_array_iterator_range &r, int array[], int size,
+		       int_array_iterator &begin, int_array_iterator &end)
+{
+  SELF_CHECK (r.begin () == begin);
+  SELF_CHECK (r.end () == end);
+  SELF_CHECK (r.size () == size);
+  SELF_CHECK (r.empty () == (size == 0));
+
+  int j = 0;
+  for (auto i : r)
+    {
+      SELF_CHECK (j < size);
+      SELF_CHECK (i == array[j]);
+      j++;
+    }
+  SELF_CHECK (j == size);
+}
+
+static void
+test_iterator_range ()
+{
+  int array[] = { 4, 4, 5, 6, 7, 8, 9 };
+  int array_size = ARRAY_SIZE (array);
+
+  int_array_iterator begin (array, array_size);
+  int_array_iterator end;
+
+  {
+    /* Constructor using begin and end.  */
+    auto r = int_array_iterator_range (begin, end);
+    test_iterator_range_1 (r, array, array_size, begin, end);
+  }
+
+  {
+    /* Constructor using begin, assuming end can be default-constructed.  */
+    auto r2 = int_array_iterator_range (begin);
+    test_iterator_range_1 (r2, array, array_size, begin, end);
+  }
+
+  {
+    /* Empty range.  */
+    auto r3 = int_array_iterator_range (end, end);
+    test_iterator_range_1 (r3, nullptr, 0, end, end);
+  }
+
+  {
+    auto r4 = int_array_iterator_range (begin, end);
+
+    /* Copy constructor.  */
+    auto r5 (r4);
+    test_iterator_range_1 (r5, array, array_size, begin, end);
+
+    /* Move constructor.  */
+    auto r6 (std::move (r4));
+    test_iterator_range_1 (r6, array, array_size, begin, end);
+  }
+
+  {
+    const auto r7 = int_array_iterator_range (begin, end);
+
+    /* Const copy constructor.  */
+    auto r8 (r7);
+    test_iterator_range_1 (r8, array, array_size, begin, end);
+  }
+}
+
+} /* namespace selftests */
+
+INIT_GDB_FILE (iterator_range_selftests)
+{
+  selftests::register_test ("iterator_range", selftests::test_iterator_range);
+}

base-commit: c365a263f5dcf95982464cf6d53db00cc6f04c1c
-- 
2.51.0

Re: [PATCH] [gdb] Add unit test for iterator_range

[Simon Marchi]

On 4/21/26 8:18 AM, Tom de Vries wrote:
> I noticed iterator_range doesn't have a selftest.  I found int_array_iterator
> in filtered_iterator-selftests.c, and decided to use that as iterator.
> 
> Factor out int-array-iterator.h out of filtered_iterator-selftests.c, and use
> it in new unit test iterator-range-selftests.c.

LGTM, thanks.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon