Move gdb_argv to gdbsupport

This moves the gdb_argv class to a new header in gdbsupport.

1 files changed, 204 insertions, 0 deletions

diff --git a/gdbsupport/buildargv.h b/gdbsupport/buildargv.h
new file mode 100644
index 0000000000..7a34d9b509
--- /dev/null
+++ b/gdbsupport/buildargv.h
@@ -0,0 +1,204 @@
+/* RAII wrapper for buildargv
+
+   Copyright (C) 2021 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 GDBSUPPORT_BUILDARGV_H
+#define GDBSUPPORT_BUILDARGV_H
+
+#include "libiberty.h"
+
+/* A wrapper for an array of char* that was allocated in the way that
+   'buildargv' does, and should be freed with 'freeargv'.  */
+
+class gdb_argv
+{
+public:
+
+  /* A constructor that initializes to NULL.  */
+
+  gdb_argv ()
+    : m_argv (NULL)
+  {
+  }
+
+  /* A constructor that calls buildargv on STR.  STR may be NULL, in
+     which case this object is initialized with a NULL array.  */
+
+  explicit gdb_argv (const char *str)
+    : m_argv (NULL)
+  {
+    reset (str);
+  }
+
+  /* A constructor that takes ownership of an existing array.  */
+
+  explicit gdb_argv (char **array)
+    : m_argv (array)
+  {
+  }
+
+  gdb_argv (const gdb_argv &) = delete;
+  gdb_argv &operator= (const gdb_argv &) = delete;
+
+  gdb_argv &operator= (gdb_argv &&other)
+  {
+    freeargv (m_argv);
+    m_argv = other.m_argv;
+    other.m_argv = nullptr;
+    return *this;
+  }
+
+  gdb_argv (gdb_argv &&other)
+  {
+    m_argv = other.m_argv;
+    other.m_argv = nullptr;
+  }
+
+  ~gdb_argv ()
+  {
+    freeargv (m_argv);
+  }
+
+  /* Call buildargv on STR, storing the result in this object.  Any
+     previous state is freed.  STR may be NULL, in which case this
+     object is reset with a NULL array.  If buildargv fails due to
+     out-of-memory, call malloc_failure.  Therefore, the value is
+     guaranteed to be non-NULL, unless the parameter itself is
+     NULL.  */
+
+  void reset (const char *str)
+  {
+    char **argv = buildargv (str);
+    freeargv (m_argv);
+    m_argv = argv;
+  }
+
+  /* Return the underlying array.  */
+
+  char **get ()
+  {
+    return m_argv;
+  }
+
+  const char * const * get () const
+  {
+    return m_argv;
+  }
+
+  /* Return the underlying array, transferring ownership to the
+     caller.  */
+
+  ATTRIBUTE_UNUSED_RESULT char **release ()
+  {
+    char **result = m_argv;
+    m_argv = NULL;
+    return result;
+  }
+
+  /* Return the number of items in the array.  */
+
+  int count () const
+  {
+    return countargv (m_argv);
+  }
+
+  /* Index into the array.  */
+
+  char *operator[] (int arg)
+  {
+    gdb_assert (m_argv != NULL);
+    return m_argv[arg];
+  }
+
+  /* Return the arguments array as an array view.  */
+
+  gdb::array_view<char *> as_array_view ()
+  {
+    return gdb::array_view<char *> (this->get (), this->count ());
+  }
+
+  gdb::array_view<const char * const> as_array_view () const
+  {
+    return gdb::array_view<const char * const> (this->get (), this->count ());
+  }
+
+  /* Append arguments to this array.  */
+  void append (gdb_argv &&other)
+  {
+    int size = count ();
+    int argc = other.count ();
+    m_argv = XRESIZEVEC (char *, m_argv, (size + argc + 1));
+
+    for (int argi = 0; argi < argc; argi++)
+      {
+	/* Transfer ownership of the string.  */
+	m_argv[size++] = other.m_argv[argi];
+	/* Ensure that destruction of OTHER works correctly.  */
+	other.m_argv[argi] = nullptr;
+      }
+    m_argv[size] = nullptr;
+  }
+
+  /* Append arguments to this array.  */
+  void append (const gdb_argv &other)
+  {
+    int size = count ();
+    int argc = other.count ();
+    m_argv = XRESIZEVEC (char *, m_argv, (size + argc + 1));
+
+    for (int argi = 0; argi < argc; argi++)
+      m_argv[size++] = xstrdup (other.m_argv[argi]);
+    m_argv[size] = nullptr;
+  }
+
+  /* The iterator type.  */
+
+  typedef char **iterator;
+
+  /* Return an iterator pointing to the start of the array.  */
+
+  iterator begin ()
+  {
+    return m_argv;
+  }
+
+  /* Return an iterator pointing to the end of the array.  */
+
+  iterator end ()
+  {
+    return m_argv + count ();
+  }
+
+  bool operator!= (std::nullptr_t)
+  {
+    return m_argv != NULL;
+  }
+
+  bool operator== (std::nullptr_t)
+  {
+    return m_argv == NULL;
+  }
+
+private:
+
+  /* The wrapped array.  */
+
+  char **m_argv;
+};
+
+#endif /* GDBSUPPORT_BUILDARGV_H */