Introduce common/common-exceptions.[ch]

This commit moves the exception throwing and catching code
into gdb/common/.  All exception printing code remains in
gdb/exceptions.[ch].

gdb/ChangeLog:

	* common/common-exceptions.h: New file.
	* common/common-exceptions.c: Likewise.
	* Makefile.in (SFILES): Add common/common-exceptions.c.
	(HFILES_NO_SRCDIR): Add common/common-exceptions.h.
	(COMMON_OBS): Add common-exceptions.o.
	(common-exceptions.o): New rule.
	* exceptions.h (common-exceptions.h): Include.
	(gdb_setjmp.h): Do not include.
	(return_reason): Moved to common-exceptions.h.
	(enum return_reason): Likewise.
	(RETURN_MASK): Likewise.
	(typedef return_mask): Likewise.
	(enum errors): Likewise.
	(struct gdb_exception): Likewise.
	(exceptions_state_mc_init): Likewise.
	(exceptions_state_mc_action_iter): Likewise.
	(exceptions_state_mc_action_iter_1): Likewise.
	(TRY_CATCH): Likewise.
	(throw_exception): Likewise.
	(throw_verror): Likewise.
	(throw_vquit): Likewise.
	(throw_error): Likewise.
	(throw_quit): Likewise.
	* exceptions.c (enum catcher_state): Moved to common-exceptions.c.
	(enum catcher_action): Likewise.
	(struct catcher): Likewise.
	(current_catcher): Likewise.
	(catcher_list_size): Likewise.
	(exceptions_state_mc_init): Likewise.
	(catcher_pop): Likewise.
	(exceptions_state_mc): Likewise.
	(exceptions_state_mc_action_iter): Likewise.
	(exceptions_state_mc_action_iter_1): Likewise.
	(throw_exception): Likewise.
	(exception_messages): Likewise.
	(exception_messages_size): Likewise.
	(throw_it): Likewise.
	(throw_verror): Likewise.
	(throw_vquit): Likewise.
	(throw_error): Likewise.
	(throw_quit): Likewise.
	(prepare_to_throw_exception): New function.

gdb/gdbserver/ChangeLog:

	* Makefile.in (SFILES): Add common/common-exceptions.c.
	(OBS): Add common-exceptions.o.
	(common-exceptions.o): New rule.
	* utils.c (prepare_to_throw_exception): New function.

1 files changed, 185 insertions, 0 deletions

diff --git a/gdb/common/common-exceptions.h b/gdb/common/common-exceptions.h
new file mode 100644
index 0000000..5f750c3
--- /dev/null
+++ b/gdb/common/common-exceptions.h
@@ -0,0 +1,185 @@
+/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
+
+   Copyright (C) 1986-2014 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_EXCEPTIONS_H
+#define COMMON_EXCEPTIONS_H
+
+#include "gdb_setjmp.h"
+
+/* Reasons for calling throw_exceptions().  NOTE: all reason values
+   must be less than zero.  enum value 0 is reserved for internal use
+   as the return value from an initial setjmp().  The function
+   catch_exceptions() reserves values >= 0 as legal results from its
+   wrapped function.  */
+
+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_GNU_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,
+
+  /* Add more errors here.  */
+  NR_ERRORS
+};
+
+struct gdb_exception
+{
+  enum return_reason reason;
+  enum errors error;
+  const char *message;
+};
+
+/* Functions to drive the 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
+   macro defined below.  */
+
+extern SIGJMP_BUF *exceptions_state_mc_init (volatile struct
+					     gdb_exception *exception,
+					     return_mask mask);
+extern int exceptions_state_mc_action_iter (void);
+extern int exceptions_state_mc_action_iter_1 (void);
+
+/* 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*
+
+   volatile struct gdb_exception e;
+   TRY_CATCH (e, RETURN_MASK_ERROR)
+     {
+     }
+   switch (e.reason)
+     {
+     case RETURN_ERROR: ...
+     }
+
+  */
+
+#define TRY_CATCH(EXCEPTION,MASK) \
+     { \
+       SIGJMP_BUF *buf = \
+	 exceptions_state_mc_init (&(EXCEPTION), (MASK)); \
+       SIGSETJMP (*buf); \
+     } \
+     while (exceptions_state_mc_action_iter ()) \
+       while (exceptions_state_mc_action_iter_1 ())
+
+/* *INDENT-ON* */
+
+/* Hook to allow client-specific actions to be performed prior to
+   throwing an exception.  This function must be provided by the
+   client, and will be called before any cleanups are run.  */
+
+extern void prepare_to_throw_exception (void);
+
+/* Throw an exception (as described by "struct gdb_exception").  Will
+   execute a LONG JUMP to the inner most containing exception handler
+   established using catch_exceptions() (or similar).
+
+   Code normally throws an exception using error() et.al.  For various
+   reaons, GDB also contains code that throws an exception directly.
+   For instance, the remote*.c targets contain CNTRL-C signal handlers
+   that propogate the QUIT event up the exception chain.  ``This could
+   be a good thing or a dangerous thing.'' -- the Existential
+   Wombat.  */
+
+extern void throw_exception (struct gdb_exception exception)
+     ATTRIBUTE_NORETURN;
+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_EXCEPTIONS_H */