gdb: Replace gdb::optional with std::optional

Since GDB now requires C++17, we don't need the internally maintained
gdb::optional implementation.  This patch does the following replacing:
  - gdb::optional -> std::optional
  - gdb::in_place -> std::in_place
  - #include "gdbsupport/gdb_optional.h" -> #include <optional>

This change has mostly been done automatically.  One exception is
gdbsupport/thread-pool.* which did not use the gdb:: prefix as it
already lives in the gdb namespace.

Change-Id: I19a92fa03e89637bab136c72e34fd351524f65e9
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>

9 files changed, 15 insertions, 15 deletions

diff --git a/gdbsupport/common-debug.h b/gdbsupport/common-debug.h
index 33b15a0..8908669 100644
--- a/gdbsupport/common-debug.h
+++ b/gdbsupport/common-debug.h
@@ -20,7 +20,7 @@
 #ifndef COMMON_COMMON_DEBUG_H
 #define COMMON_COMMON_DEBUG_H
 
-#include "gdbsupport/gdb_optional.h"
+#include <optional>
 #include "gdbsupport/preprocessor.h"
 
 #include <stdarg.h>
@@ -200,7 +200,7 @@ private:
   const char *m_end_prefix;
 
   /* The result of formatting the format string in the constructor.  */
-  gdb::optional<std::string> m_msg;
+  std::optional<std::string> m_msg;
 
   /* True is a non-nullptr format was passed to the constructor.  */
   bool m_with_format;
diff --git a/gdbsupport/event-loop.cc b/gdbsupport/event-loop.cc
index 52e7fd2..031c2ff 100644
--- a/gdbsupport/event-loop.cc
+++ b/gdbsupport/event-loop.cc
@@ -33,7 +33,7 @@
 #include <sys/types.h>
 #include "gdbsupport/gdb_sys_time.h"
 #include "gdbsupport/gdb_select.h"
-#include "gdbsupport/gdb_optional.h"
+#include <optional>
 #include "gdbsupport/scope-exit.h"
 
 /* See event-loop.h.  */
@@ -246,7 +246,7 @@ gdb_do_one_event (int mstimeout)
      When the timeout is reached, events are not monitored again:
      they already have been checked in the loop above. */
 
-  gdb::optional<int> timer_id;
+  std::optional<int> timer_id;
 
   SCOPE_EXIT 
     {
@@ -258,7 +258,7 @@ gdb_do_one_event (int mstimeout)
     timer_id = create_timer (mstimeout,
 			     [] (gdb_client_data arg)
 			     {
-			       ((gdb::optional<int> *) arg)->reset ();
+			       ((std::optional<int> *) arg)->reset ();
 			     },
 			     &timer_id);
   return gdb_wait_for_event (1);
diff --git a/gdbsupport/filestuff.cc b/gdbsupport/filestuff.cc
index 9e61fea..334bae8 100644
--- a/gdbsupport/filestuff.cc
+++ b/gdbsupport/filestuff.cc
@@ -504,7 +504,7 @@ mkdir_recursive (const char *dir)
 
 /* See gdbsupport/filestuff.h.  */
 
-gdb::optional<std::string>
+std::optional<std::string>
 read_text_file_to_string (const char *path)
 {
   gdb_file_up file = gdb_fopen_cloexec (path, "r");
diff --git a/gdbsupport/filestuff.h b/gdbsupport/filestuff.h
index 48bef51..206b51e 100644
--- a/gdbsupport/filestuff.h
+++ b/gdbsupport/filestuff.h
@@ -131,6 +131,6 @@ extern bool mkdir_recursive (const char *dir);
 
 /* Read the entire content of file PATH into an std::string.  */
 
-extern gdb::optional<std::string> read_text_file_to_string (const char *path);
+extern std::optional<std::string> read_text_file_to_string (const char *path);
 
 #endif /* COMMON_FILESTUFF_H */
diff --git a/gdbsupport/forward-scope-exit.h b/gdbsupport/forward-scope-exit.h
index bf591dd..0552e11 100644
--- a/gdbsupport/forward-scope-exit.h
+++ b/gdbsupport/forward-scope-exit.h
@@ -52,9 +52,9 @@
       obj.release ();  // Optional cancel if needed.
 
    forward_scope_exit is also handy when you would need to wrap a
-   scope_exit in a gdb::optional:
+   scope_exit in a std::optional:
 
-      gdb::optional<longjmp_breakpoint_cleanup> cleanup;
+      std::optional<longjmp_breakpoint_cleanup> cleanup;
       if (some condition)
 	cleanup.emplace (thread);
       ...
@@ -62,7 +62,7 @@
 	cleanup->release ();
 
    since with scope exit, you would have to know the scope_exit's
-   callable template type when you create the gdb::optional:
+   callable template type when you create the std::optional:
 
      gdb:optional<scope_exit<what goes here?>>
 
diff --git a/gdbsupport/range-chain.h b/gdbsupport/range-chain.h
index 01d6cf0..3cebce0 100644
--- a/gdbsupport/range-chain.h
+++ b/gdbsupport/range-chain.h
@@ -90,7 +90,7 @@ struct range_chain
     /* The current iterator into one of the vector ranges.  If no
        value then this (outer) iterator is at the end of the overall
        range.  */
-    gdb::optional<typename Range::iterator> m_current;
+    std::optional<typename Range::iterator> m_current;
     /* Vector of ranges.  */
     const std::vector<Range> &m_ranges;
   };
diff --git a/gdbsupport/scoped_ignore_sigttou.h b/gdbsupport/scoped_ignore_sigttou.h
index a3f8361..558fb7f 100644
--- a/gdbsupport/scoped_ignore_sigttou.h
+++ b/gdbsupport/scoped_ignore_sigttou.h
@@ -26,7 +26,7 @@
 #ifdef SIGTTOU
 
 /* Simple wrapper that allows lazy initialization / destruction of T.
-   Slightly more efficient than gdb::optional, because it doesn't
+   Slightly more efficient than std::optional, because it doesn't
    carry storage to track whether the object has been initialized.  */
 template<typename T>
 class lazy_init
diff --git a/gdbsupport/thread-pool.cc b/gdbsupport/thread-pool.cc
index 1c871ed..bbe043d 100644
--- a/gdbsupport/thread-pool.cc
+++ b/gdbsupport/thread-pool.cc
@@ -225,7 +225,7 @@ thread_pool::thread_function ()
 
   while (true)
     {
-      optional<task_t> t;
+      std::optional<task_t> t;
 
       {
 	/* We want to hold the lock while examining the task list, but
diff --git a/gdbsupport/thread-pool.h b/gdbsupport/thread-pool.h
index cb8696e..d5e1dc7 100644
--- a/gdbsupport/thread-pool.h
+++ b/gdbsupport/thread-pool.h
@@ -30,7 +30,7 @@
 #include <condition_variable>
 #include <future>
 #endif
-#include "gdbsupport/gdb_optional.h"
+#include <optional>
 
 namespace gdb
 {
@@ -198,7 +198,7 @@ private:
      to represent a task.  If the optional is empty, then this means
      that the receiving thread should terminate.  If the optional is
      non-empty, then it is an actual task to evaluate.  */
-  std::queue<optional<task_t>> m_tasks;
+  std::queue<std::optional<task_t>> m_tasks;
 
   /* A condition variable and mutex that are used for communication
      between the main thread and the worker threads.  */