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diff --git a/gdb/gdbsupport/common-exceptions.h b/gdb/gdbsupport/common-exceptions.h
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+++ b/gdb/gdbsupport/common-exceptions.h
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+/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
+
+   Copyright (C) 1986-2019 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 COMMON_COMMON_EXCEPTIONS_H
+#define COMMON_COMMON_EXCEPTIONS_H
+
+#include <setjmp.h>
+#include <new>
+#include <memory>
+#include <string>
+
+/* Reasons for calling throw_exceptions().  NOTE: all reason values
+   must be different from zero.  enum value 0 is reserved for internal
+   use as the return value from an initial setjmp().  */
+
+enum return_reason
+  {
+    /* User interrupt.  */
+    RETURN_QUIT = -2,
+    /* Any other error.  */
+    RETURN_ERROR
+  };
+
+#define RETURN_MASK(reason)	(1 << (int)(-reason))
+
+typedef enum
+{
+  RETURN_MASK_QUIT = RETURN_MASK (RETURN_QUIT),
+  RETURN_MASK_ERROR = RETURN_MASK (RETURN_ERROR),
+  RETURN_MASK_ALL = (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
+} return_mask;
+
+/* Describe all exceptions.  */
+
+enum errors {
+  GDB_NO_ERROR,
+
+  /* Any generic error, the corresponding text is in
+     exception.message.  */
+  GENERIC_ERROR,
+
+  /* Something requested was not found.  */
+  NOT_FOUND_ERROR,
+
+  /* Thread library lacks support necessary for finding thread local
+     storage.  */
+  TLS_NO_LIBRARY_SUPPORT_ERROR,
+
+  /* Load module not found while attempting to find thread local storage.  */
+  TLS_LOAD_MODULE_NOT_FOUND_ERROR,
+
+  /* Thread local storage has not been allocated yet.  */
+  TLS_NOT_ALLOCATED_YET_ERROR,
+
+  /* Something else went wrong while attempting to find thread local
+     storage.  The ``struct gdb_exception'' message field provides
+     more detail.  */
+  TLS_GENERIC_ERROR,
+
+  /* Problem parsing an XML document.  */
+  XML_PARSE_ERROR,
+
+  /* Error accessing memory.  */
+  MEMORY_ERROR,
+
+  /* Value not available.  E.g., a register was not collected in a
+     traceframe.  */
+  NOT_AVAILABLE_ERROR,
+
+  /* Value was optimized out.  Note: if the value was a register, this
+     means the register was not saved in the frame.  */
+  OPTIMIZED_OUT_ERROR,
+
+  /* DW_OP_entry_value resolving failed.  */
+  NO_ENTRY_VALUE_ERROR,
+
+  /* Target throwing an error has been closed.  Current command should be
+     aborted as the inferior state is no longer valid.  */
+  TARGET_CLOSE_ERROR,
+
+  /* An undefined command was executed.  */
+  UNDEFINED_COMMAND_ERROR,
+
+  /* Requested feature, method, mechanism, etc. is not supported.  */
+  NOT_SUPPORTED_ERROR,
+
+  /* The number of candidates generated during line completion has
+     reached the user's specified limit.  This isn't an error, this exception
+     is used to halt searching for more completions, but for consistency
+     "_ERROR" is appended to the name.  */
+  MAX_COMPLETIONS_REACHED_ERROR,
+
+  /* Add more errors here.  */
+  NR_ERRORS
+};
+
+struct gdb_exception
+{
+  gdb_exception ()
+    : reason ((enum return_reason) 0),
+      error (GDB_NO_ERROR)
+  {
+  }
+
+  gdb_exception (enum return_reason r, enum errors e)
+    : reason (r),
+      error (e)
+  {
+  }
+
+  gdb_exception (enum return_reason r, enum errors e,
+		 const char *fmt, va_list ap)
+    ATTRIBUTE_PRINTF (4, 0)
+    : reason (r),
+      error (e),
+      message (std::make_shared<std::string> (string_vprintf (fmt, ap)))
+  {
+  }
+
+  /* The move constructor exists so that we can mark it "noexcept",
+     which is a good practice for any sort of exception object.  */
+  explicit gdb_exception (gdb_exception &&other) noexcept = default;
+
+  /* The copy constructor exists so that we can mark it "noexcept",
+     which is a good practice for any sort of exception object.  */
+  gdb_exception (const gdb_exception &other) noexcept
+    : reason (other.reason),
+      error (other.error),
+      message (other.message)
+  {
+  }
+
+  /* The assignment operator exists so that we can mark it "noexcept",
+     which is a good practice for any sort of exception object.  */
+  gdb_exception &operator= (const gdb_exception &other) noexcept
+  {
+    reason = other.reason;
+    error = other.error;
+    message = other.message;
+    return *this;
+  }
+
+  gdb_exception &operator= (gdb_exception &&other) noexcept = default;
+
+  /* Return the contents of the exception message, as a C string.  The
+     string remains owned by the exception object.  */
+  const char *what () const noexcept
+  {
+    return message->c_str ();
+  }
+
+  enum return_reason reason;
+  enum errors error;
+  std::shared_ptr<std::string> message;
+};
+
+/* Functions to drive the sjlj-based exceptions state machine.  Though
+   declared here by necessity, these functions should be considered
+   internal to the exceptions subsystem and not used other than via
+   the TRY/CATCH (or TRY_SJLJ/CATCH_SJLJ) macros defined below.  */
+
+extern jmp_buf *exceptions_state_mc_init (void);
+extern int exceptions_state_mc_action_iter (void);
+extern int exceptions_state_mc_action_iter_1 (void);
+extern int exceptions_state_mc_catch (struct gdb_exception *, int);
+
+/* Macro to wrap up standard try/catch behavior.
+
+   The double loop lets us correctly handle code "break"ing out of the
+   try catch block.  (It works as the "break" only exits the inner
+   "while" loop, the outer for loop detects this handling it
+   correctly.)  Of course "return" and "goto" are not so lucky.
+
+   For instance:
+
+   *INDENT-OFF*
+
+   TRY_SJLJ
+     {
+     }
+   CATCH_SJLJ (e, RETURN_MASK_ERROR)
+     {
+       switch (e.reason)
+         {
+           case RETURN_ERROR: ...
+         }
+     }
+   END_CATCH_SJLJ
+
+   The SJLJ variants are needed in some cases where gdb exceptions
+   need to cross third-party library code compiled without exceptions
+   support (e.g., readline).  */
+
+#define TRY_SJLJ \
+     { \
+       jmp_buf *buf = \
+	 exceptions_state_mc_init (); \
+       setjmp (*buf); \
+     } \
+     while (exceptions_state_mc_action_iter ()) \
+       while (exceptions_state_mc_action_iter_1 ())
+
+#define CATCH_SJLJ(EXCEPTION, MASK)				\
+  {							\
+    struct gdb_exception EXCEPTION;				\
+    if (exceptions_state_mc_catch (&(EXCEPTION), MASK))
+
+#define END_CATCH_SJLJ				\
+  }
+
+/* The exception types client code may catch.  They're just shims
+   around gdb_exception that add nothing but type info.  Which is used
+   is selected depending on the MASK argument passed to CATCH.  */
+
+struct gdb_exception_error : public gdb_exception
+{
+  gdb_exception_error (enum errors e, const char *fmt, va_list ap)
+    ATTRIBUTE_PRINTF (3, 0)
+    : gdb_exception (RETURN_ERROR, e, fmt, ap)
+  {
+  }
+
+  explicit gdb_exception_error (gdb_exception &&ex) noexcept
+    : gdb_exception (std::move (ex))
+  {
+    gdb_assert (ex.reason == RETURN_ERROR);
+  }
+};
+
+struct gdb_exception_quit : public gdb_exception
+{
+  gdb_exception_quit (const char *fmt, va_list ap)
+    ATTRIBUTE_PRINTF (2, 0)
+    : gdb_exception (RETURN_QUIT, GDB_NO_ERROR, fmt, ap)
+  {
+  }
+
+  explicit gdb_exception_quit (gdb_exception &&ex) noexcept
+    : gdb_exception (std::move (ex))
+  {
+    gdb_assert (ex.reason == RETURN_QUIT);
+  }
+};
+
+/* An exception type that inherits from both std::bad_alloc and a gdb
+   exception.  This is necessary because operator new can only throw
+   std::bad_alloc, and OTOH, we want exceptions thrown due to memory
+   allocation error to be caught by all the CATCH/RETURN_MASK_ALL
+   spread around the codebase.  */
+
+struct gdb_quit_bad_alloc
+  : public gdb_exception_quit,
+    public std::bad_alloc
+{
+  explicit gdb_quit_bad_alloc (gdb_exception &&ex) noexcept
+    : gdb_exception_quit (std::move (ex)),
+      std::bad_alloc ()
+  {
+  }
+};
+
+/* *INDENT-ON* */
+
+/* Throw an exception (as described by "struct gdb_exception"),
+   landing in the inner most containing exception handler established
+   using TRY/CATCH.  */
+extern void throw_exception (gdb_exception &&exception)
+     ATTRIBUTE_NORETURN;
+
+/* Throw an exception by executing a LONG JUMP to the inner most
+   containing exception handler established using TRY_SJLJ.  Necessary
+   in some cases where we need to throw GDB exceptions across
+   third-party library code (e.g., readline).  */
+extern void throw_exception_sjlj (const struct gdb_exception &exception)
+     ATTRIBUTE_NORETURN;
+
+/* Convenience wrappers around throw_exception that throw GDB
+   errors.  */
+extern void throw_verror (enum errors, const char *fmt, va_list ap)
+     ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 0);
+extern void throw_vquit (const char *fmt, va_list ap)
+     ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 0);
+extern void throw_error (enum errors error, const char *fmt, ...)
+     ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3);
+extern void throw_quit (const char *fmt, ...)
+     ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 2);
+
+#endif /* COMMON_COMMON_EXCEPTIONS_H */