[binutils-gdb] gdbsupport: remove variadicity from basic_safe_iterator constructors

[Simon Marchi]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ff20aab941bc9bb1e79011fd5dff94b16a203df0

commit ff20aab941bc9bb1e79011fd5dff94b16a203df0
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Wed Sep 3 10:50:03 2025 -0400

    gdbsupport: remove variadicity from basic_safe_iterator constructors
    
    Change the constructors to accept `Iterator` objects directly.  This
    requires the callers to explicitly pass `Iterator` object (unless
    perhaps `Iterator` has a non-explicit one-argument constructor.
    
    The rationale is the same as the previous patch: make the code easier to
    follow and make it easier to fix build errors, at the expense of making
    callers more explicit.
    
    Change-Id: Icd2a4ef971456ca250f96227a9b83c935d619451
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/gdbthread.h            |  5 +++--
 gdb/inferior.h             | 10 ++++++----
 gdbsupport/safe-iterator.h | 28 +++++++++++-----------------
 3 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index 44f95c6fff4..26bd9f2b7e7 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -794,9 +794,10 @@ all_non_exited_threads (process_stratum_target *proc_target = nullptr,
 inline all_threads_safe_range
 all_threads_safe ()
 {
-  all_threads_safe_iterator begin (all_threads_iterator::begin_t {});
+  all_threads_iterator begin (all_threads_iterator::begin_t {});
+  all_threads_safe_iterator safe_begin (std::move (begin));
 
-  return all_threads_safe_range (std::move (begin));
+  return all_threads_safe_range (std::move (safe_begin));
 }
 
 extern int thread_count (process_stratum_target *proc_target);
diff --git a/gdb/inferior.h b/gdb/inferior.h
index b02ec57b5de..2e396ae11ce 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -502,9 +502,10 @@ public:
   */
   inline safe_inf_threads_range threads_safe ()
   {
-    safe_inf_threads_iterator begin (this->thread_list.begin ());
+    inf_threads_iterator begin (this->thread_list.begin ());
+    safe_inf_threads_iterator safe_begin (std::move (begin));
 
-    return safe_inf_threads_range (std::move (begin));
+    return safe_inf_threads_range (std::move (safe_begin));
   }
 
   /* Find (non-exited) thread PTID of this inferior.  */
@@ -832,9 +833,10 @@ extern intrusive_list<inferior> inferior_list;
 inline all_inferiors_safe_range
 all_inferiors_safe ()
 {
-  all_inferiors_safe_iterator begin (nullptr, inferior_list);
+  all_inferiors_iterator begin (nullptr, inferior_list);
+  all_inferiors_safe_iterator safe_begin (std::move (begin));
 
-  return all_inferiors_safe_range (std::move (begin));
+  return all_inferiors_safe_range (std::move (safe_begin));
 }
 
 /* Returns a range representing all inferiors, suitable to use with
diff --git a/gdbsupport/safe-iterator.h b/gdbsupport/safe-iterator.h
index 53881603934..4cb9a198037 100644
--- a/gdbsupport/safe-iterator.h
+++ b/gdbsupport/safe-iterator.h
@@ -50,30 +50,24 @@ public:
   typedef typename Iterator::iterator_category iterator_category;
   typedef typename Iterator::difference_type difference_type;
 
-  /* Construct the begin iterator using the given arguments; the end iterator is
-     default constructed.  */
-  template<typename... Args>
-  explicit basic_safe_iterator (Args &&...args)
-    : m_it (std::forward<Args> (args)...),
-      m_next (m_it)
-  {
-    if (m_it != m_end)
-      ++m_next;
-  }
+  /* Construct the iterator using the underlying iterator BEGIN; the end
+     iterator is default constructed.  */
+  explicit basic_safe_iterator (Iterator begin)
+    : basic_safe_iterator (std::move (begin), Iterator {})
+  {}
 
-  /* Construct the iterator using the first argument, and construct
-     the end iterator using the second argument.  */
-  template<typename Arg>
-  explicit basic_safe_iterator (Arg &&arg, Arg &&arg2)
-    : m_it (std::forward<Arg> (arg)),
+  /* Construct the iterator using the underlying iterators BEGIN and END.  */
+  basic_safe_iterator (Iterator begin, Iterator end)
+    : m_it (std::move (begin)),
       m_next (m_it),
-      m_end (std::forward<Arg> (arg2))
+      m_end (std::move (end))
   {
     if (m_it != m_end)
       ++m_next;
   }
 
-  /* Create a one-past-end iterator.  */
+  /* Create a one-past-end iterator.  The underlying end iterator is obtained
+     by default-constructing.  */
   basic_safe_iterator ()
   {}