[PATCH 1/2] Allow move of compiled_regex

[Tom Tromey <tromey@adacore.com>]

This patch makes it possible to move a compiled_regex.
---
 gdbsupport/gdb_regex.cc | 13 +++++++++++--
 gdbsupport/gdb_regex.h  | 30 +++++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/gdbsupport/gdb_regex.cc b/gdbsupport/gdb_regex.cc
index 111e5ff24a8..6774aa4c805 100644
--- a/gdbsupport/gdb_regex.cc
+++ b/gdbsupport/gdb_regex.cc
@@ -33,17 +33,25 @@ compiled_regex::compiled_regex (const char *regex, int cflags,
       regerror (code, &m_pattern, err.data (), length);
       error (("%s: %s"), message, err.data ());
     }
+
+  m_valid = true;
 }
 
-compiled_regex::~compiled_regex ()
+void
+compiled_regex::clear ()
 {
-  regfree (&m_pattern);
+  if (m_valid)
+    {
+      regfree (&m_pattern);
+      m_valid = false;
+    }
 }
 
 int
 compiled_regex::exec (const char *string, size_t nmatch,
 		      regmatch_t pmatch[], int eflags) const
 {
+  gdb_assert (m_valid);
   return regexec (&m_pattern, string, nmatch, pmatch, eflags);
 }
 
@@ -52,5 +60,6 @@ compiled_regex::search (const char *string,
 			int length, int start, int range,
 			struct re_registers *regs)
 {
+  gdb_assert (m_valid);
   return re_search (&m_pattern, string, length, start, range, regs);
 }
diff --git a/gdbsupport/gdb_regex.h b/gdbsupport/gdb_regex.h
index 63fd9c32119..f7d3190839f 100644
--- a/gdbsupport/gdb_regex.h
+++ b/gdbsupport/gdb_regex.h
@@ -35,10 +35,32 @@ class compiled_regex
 		  const char *message)
     ATTRIBUTE_NONNULL (2) ATTRIBUTE_NONNULL (4);
 
-  ~compiled_regex ();
+  ~compiled_regex ()
+  {
+    clear ();
+  }
 
   DISABLE_COPY_AND_ASSIGN (compiled_regex);
 
+  compiled_regex (compiled_regex &&other)
+    : m_valid (other.m_valid),
+      m_pattern (other.m_pattern)
+  {
+    other.m_valid = false;
+  }
+
+  compiled_regex &operator= (compiled_regex &&other)
+  {
+    if (&other != this)
+      {
+	clear ();
+	m_valid = other.m_valid;
+	m_pattern = other.m_pattern;
+	other.m_valid = false;
+      }
+    return *this;
+  }
+
   /* Wrapper around ::regexec.  */
   int exec (const char *string,
 	    size_t nmatch, regmatch_t pmatch[],
@@ -50,6 +72,12 @@ class compiled_regex
 	      int range, struct re_registers *regs);
 
 private:
+  /* Free the compiled pattern, if necessary.  */
+  void clear ();
+
+  /* True if the compiled pattern is valid.  */
+  bool m_valid = false;
+
   /* The compiled pattern.  */
   regex_t m_pattern;
 };

-- 
2.53.0