From e31806255fe0cf49a1eeb14a51788473eaaa6310 Mon Sep 17 00:00:00 2001 From: Gary Benson Date: Mon, 4 Aug 2014 11:37:44 +0100 Subject: Move cleanups.[ch] to common This commit moves cleanups.[ch] into gdb/common/. The only change to the content of the files is that cleanups.c's include list was altered to match its new location. gdb/ChangeLog: * cleanups.h: Moved to... * common/cleanups.h: New file. * cleanups.c: Moved to... * common/cleanups.c: New file. Include common-defs.h and cleanups.h. Do not include defs.h. * Makefile.in (SFILES): Replace cleanups.c with common/cleanups.c. (HFILES_NO_SRCDIR): Replace cleanups.h with common/cleanups.h. (cleanups.o): New rule. gdb/gdbserver/ChangeLog: * Makefile.in (SFILES): Add common/cleanups.c. (OBS): cleanups.o. (cleanups.o): New rule. --- gdb/common/cleanups.c | 297 ++++++++++++++++++++++++++++++++++++++++++++++++++ gdb/common/cleanups.h | 69 ++++++++++++ 2 files changed, 366 insertions(+) create mode 100644 gdb/common/cleanups.c create mode 100644 gdb/common/cleanups.h (limited to 'gdb/common') diff --git a/gdb/common/cleanups.c b/gdb/common/cleanups.c new file mode 100644 index 0000000..49b643b --- /dev/null +++ b/gdb/common/cleanups.c @@ -0,0 +1,297 @@ +/* Cleanup routines 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 . */ + +#include "common-defs.h" +#include "cleanups.h" + +/* The cleanup list records things that have to be undone + if an error happens (descriptors to be closed, memory to be freed, etc.) + Each link in the chain records a function to call and an + argument to give it. + + Use make_cleanup to add an element to the cleanup chain. + Use do_cleanups to do all cleanup actions back to a given + point in the chain. Use discard_cleanups to remove cleanups + from the chain back to a given point, not doing them. + + If the argument is pointer to allocated memory, then you need + to additionally set the 'free_arg' member to a function that will + free that memory. This function will be called both when the cleanup + is executed and when it's discarded. */ + +struct cleanup +{ + struct cleanup *next; + void (*function) (void *); + void (*free_arg) (void *); + void *arg; +}; + +/* Used to mark the end of a cleanup chain. + The value is chosen so that it: + - is non-NULL so that make_cleanup never returns NULL, + - causes a segv if dereferenced + [though this won't catch errors that a value of, say, + ((struct cleanup *) -1) will] + - displays as something useful when printed in gdb. + This is const for a bit of extra robustness. + It is initialized to coax gcc into putting it into .rodata. + All fields are initialized to survive -Wextra. */ +static const struct cleanup sentinel_cleanup = { 0, 0, 0, 0 }; + +/* Handy macro to use when referring to sentinel_cleanup. */ +#define SENTINEL_CLEANUP ((struct cleanup *) &sentinel_cleanup) + +/* Chain of cleanup actions established with make_cleanup, + to be executed if an error happens. */ +static struct cleanup *cleanup_chain = SENTINEL_CLEANUP; + +/* Chain of cleanup actions established with make_final_cleanup, + to be executed when gdb exits. */ +static struct cleanup *final_cleanup_chain = SENTINEL_CLEANUP; + +/* Main worker routine to create a cleanup. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + FUNCTION is the function to call to perform the cleanup. + ARG is passed to FUNCTION when called. + FREE_ARG, if non-NULL, is called after the cleanup is performed. + + The result is a pointer to the previous chain pointer + to be passed later to do_cleanups or discard_cleanups. */ + +static struct cleanup * +make_my_cleanup2 (struct cleanup **pmy_chain, make_cleanup_ftype *function, + void *arg, void (*free_arg) (void *)) +{ + struct cleanup *new + = (struct cleanup *) xmalloc (sizeof (struct cleanup)); + struct cleanup *old_chain = *pmy_chain; + + new->next = *pmy_chain; + new->function = function; + new->free_arg = free_arg; + new->arg = arg; + *pmy_chain = new; + + gdb_assert (old_chain != NULL); + return old_chain; +} + +/* Worker routine to create a cleanup without a destructor. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + FUNCTION is the function to call to perform the cleanup. + ARG is passed to FUNCTION when called. + + The result is a pointer to the previous chain pointer + to be passed later to do_cleanups or discard_cleanups. */ + +static struct cleanup * +make_my_cleanup (struct cleanup **pmy_chain, make_cleanup_ftype *function, + void *arg) +{ + return make_my_cleanup2 (pmy_chain, function, arg, NULL); +} + +/* Add a new cleanup to the cleanup_chain, + and return the previous chain pointer + to be passed later to do_cleanups or discard_cleanups. + Args are FUNCTION to clean up with, and ARG to pass to it. */ + +struct cleanup * +make_cleanup (make_cleanup_ftype *function, void *arg) +{ + return make_my_cleanup (&cleanup_chain, function, arg); +} + +/* Same as make_cleanup except also includes TDOR, a destructor to free ARG. + DTOR is invoked when the cleanup is performed or when it is discarded. */ + +struct cleanup * +make_cleanup_dtor (make_cleanup_ftype *function, void *arg, + void (*dtor) (void *)) +{ + return make_my_cleanup2 (&cleanup_chain, + function, arg, dtor); +} + +/* Same as make_cleanup except the cleanup is added to final_cleanup_chain. */ + +struct cleanup * +make_final_cleanup (make_cleanup_ftype *function, void *arg) +{ + return make_my_cleanup (&final_cleanup_chain, function, arg); +} + +/* Worker routine to perform cleanups. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + OLD_CHAIN is the result of a "make" cleanup routine. + Cleanups are performed until we get back to the old end of the chain. */ + +static void +do_my_cleanups (struct cleanup **pmy_chain, + struct cleanup *old_chain) +{ + struct cleanup *ptr; + + while ((ptr = *pmy_chain) != old_chain) + { + *pmy_chain = ptr->next; /* Do this first in case of recursion. */ + (*ptr->function) (ptr->arg); + if (ptr->free_arg) + (*ptr->free_arg) (ptr->arg); + xfree (ptr); + } +} + +/* Return a value that can be passed to do_cleanups, do_final_cleanups to + indicate perform all cleanups. */ + +struct cleanup * +all_cleanups (void) +{ + return SENTINEL_CLEANUP; +} + +/* Discard cleanups and do the actions they describe + until we get back to the point OLD_CHAIN in the cleanup_chain. */ + +void +do_cleanups (struct cleanup *old_chain) +{ + do_my_cleanups (&cleanup_chain, old_chain); +} + +/* Discard cleanups and do the actions they describe + until we get back to the point OLD_CHAIN in the final_cleanup_chain. */ + +void +do_final_cleanups (struct cleanup *old_chain) +{ + do_my_cleanups (&final_cleanup_chain, old_chain); +} + +/* Main worker routine to discard cleanups. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + OLD_CHAIN is the result of a "make" cleanup routine. + Cleanups are discarded until we get back to the old end of the chain. */ + +static void +discard_my_cleanups (struct cleanup **pmy_chain, + struct cleanup *old_chain) +{ + struct cleanup *ptr; + + while ((ptr = *pmy_chain) != old_chain) + { + *pmy_chain = ptr->next; + if (ptr->free_arg) + (*ptr->free_arg) (ptr->arg); + xfree (ptr); + } +} + +/* Discard cleanups, not doing the actions they describe, + until we get back to the point OLD_CHAIN in the cleanup chain. */ + +void +discard_cleanups (struct cleanup *old_chain) +{ + discard_my_cleanups (&cleanup_chain, old_chain); +} + +/* Discard final cleanups, not doing the actions they describe, + until we get back to the point OLD_CHAIN in the final cleanup chain. */ + +void +discard_final_cleanups (struct cleanup *old_chain) +{ + discard_my_cleanups (&final_cleanup_chain, old_chain); +} + +/* Main worker routine to save cleanups. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + The chain is emptied and the result is a pointer to the old chain. */ + +static struct cleanup * +save_my_cleanups (struct cleanup **pmy_chain) +{ + struct cleanup *old_chain = *pmy_chain; + + *pmy_chain = SENTINEL_CLEANUP; + return old_chain; +} + +/* Set the cleanup_chain to 0, and return the old cleanup_chain. */ + +struct cleanup * +save_cleanups (void) +{ + return save_my_cleanups (&cleanup_chain); +} + +/* Set the final_cleanup_chain to 0, and return the old + final_cleanup_chain. */ + +struct cleanup * +save_final_cleanups (void) +{ + return save_my_cleanups (&final_cleanup_chain); +} + +/* Main worker routine to save cleanups. + PMY_CHAIN is a pointer to either cleanup_chain or final_cleanup_chain. + The chain is restored from CHAIN. */ + +static void +restore_my_cleanups (struct cleanup **pmy_chain, struct cleanup *chain) +{ + if (*pmy_chain != SENTINEL_CLEANUP) + internal_warning (__FILE__, __LINE__, + _("restore_my_cleanups has found a stale cleanup")); + + *pmy_chain = chain; +} + +/* Restore the cleanup chain from a previously saved chain. */ + +void +restore_cleanups (struct cleanup *chain) +{ + restore_my_cleanups (&cleanup_chain, chain); +} + +/* Restore the final cleanup chain from a previously saved chain. */ + +void +restore_final_cleanups (struct cleanup *chain) +{ + restore_my_cleanups (&final_cleanup_chain, chain); +} + +/* Provide a known function that does nothing, to use as a base for + a possibly long chain of cleanups. This is useful where we + use the cleanup chain for handling normal cleanups as well as dealing + with cleanups that need to be done as a result of a call to error(). + In such cases, we may not be certain where the first cleanup is, unless + we have a do-nothing one to always use as the base. */ + +void +null_cleanup (void *arg) +{ +} diff --git a/gdb/common/cleanups.h b/gdb/common/cleanups.h new file mode 100644 index 0000000..aad5add --- /dev/null +++ b/gdb/common/cleanups.h @@ -0,0 +1,69 @@ +/* Cleanups. + 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 . */ + +#ifndef CLEANUPS_H +#define CLEANUPS_H + +/* Outside of cleanups.c, this is an opaque type. */ +struct cleanup; + +/* NOTE: cagney/2000-03-04: This typedef is strictly for the + make_cleanup function declarations below. Do not use this typedef + as a cast when passing functions into the make_cleanup() code. + Instead either use a bounce function or add a wrapper function. + Calling a f(char*) function with f(void*) is non-portable. */ +typedef void (make_cleanup_ftype) (void *); + +/* Function type for the dtor in make_cleanup_dtor. */ +typedef void (make_cleanup_dtor_ftype) (void *); + +/* WARNING: The result of the "make cleanup" routines is not the intuitive + choice of being a handle on the just-created cleanup. Instead it is an + opaque handle of the cleanup mechanism and represents all cleanups created + from that point onwards. + The result is guaranteed to be non-NULL though. */ + +extern struct cleanup *make_cleanup (make_cleanup_ftype *, void *); + +extern struct cleanup *make_cleanup_dtor (make_cleanup_ftype *, void *, + make_cleanup_dtor_ftype *); + +extern struct cleanup *make_final_cleanup (make_cleanup_ftype *, void *); + +/* A special value to pass to do_cleanups and do_final_cleanups + to tell them to do all cleanups. */ +extern struct cleanup *all_cleanups (void); + +extern void do_cleanups (struct cleanup *); +extern void do_final_cleanups (struct cleanup *); + +extern void discard_cleanups (struct cleanup *); +extern void discard_final_cleanups (struct cleanup *); + +extern struct cleanup *save_cleanups (void); +extern struct cleanup *save_final_cleanups (void); + +extern void restore_cleanups (struct cleanup *); +extern void restore_final_cleanups (struct cleanup *); + +/* A no-op cleanup. + This is useful when you want to establish a known reference point + to pass to do_cleanups. */ +extern void null_cleanup (void *); + +#endif /* CLEANUPS_H */ -- cgit v1.1