- Convert new_fork and free_fork to fork_info ctor/dtor.
- Use std::list.
gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* linux-fork.c: Include <list>.
(fork_list): Now a std::list instance.
(fork_info): Add ctor, dtor, and in-class initialize all fields.
(forks_exist_p, find_last_fork): Adjust.
(new_fork): Delete.
(one_fork_p): New.
(add_fork): Adjust.
(free_fork): Delete, folded into fork_info::~fork_info().
(delete_fork, find_fork_ptid, find_fork_id, find_fork_pid):
Adjust.
(init_fork_list): Delete.
(linux_fork_killall, linux_fork_mourn_inferior)
(linux_fork_detach, info_checkpoints_command): Adjust.
(_initialize_linux_fork): No longer call init_fork_list.
---
gdb/linux-fork.c | 261 +++++++++++++++++++++++--------------------------------
1 file changed, 108 insertions(+), 153 deletions(-)
@@ -35,30 +35,66 @@
#include <dirent.h>
#include <ctype.h>
-struct fork_info *fork_list;
-static int highest_fork_num;
+#include <list>
/* Fork list data structure: */
struct fork_info
{
- struct fork_info *next;
- ptid_t ptid;
- ptid_t parent_ptid;
- int num; /* Convenient handle (GDB fork id). */
- readonly_detached_regcache *savedregs; /* Convenient for info fork, saves
- having to actually switch contexts. */
- CORE_ADDR pc;
- int clobber_regs; /* True if we should restore saved regs. */
- off_t *filepos; /* Set of open file descriptors' offsets. */
- int maxfd;
+ explicit fork_info (pid_t pid)
+ : ptid (pid, pid, 0)
+ {
+ }
+
+ ~fork_info ()
+ {
+ /* Notes on step-resume breakpoints: since this is a concern for
+ threads, let's convince ourselves that it's not a concern for
+ forks. There are two ways for a fork_info to be created.
+ First, by the checkpoint command, in which case we're at a gdb
+ prompt and there can't be any step-resume breakpoint. Second,
+ by a fork in the user program, in which case we *may* have
+ stepped into the fork call, but regardless of whether we follow
+ the parent or the child, we will return to the same place and
+ the step-resume breakpoint, if any, will take care of itself as
+ usual. And unlike threads, we do not save a private copy of
+ the step-resume breakpoint -- so we're OK. */
+
+ if (savedregs)
+ delete savedregs;
+ if (filepos)
+ xfree (filepos);
+ }
+
+ ptid_t ptid = null_ptid;
+ ptid_t parent_ptid = null_ptid;
+
+ /* Convenient handle (GDB fork id). */
+ int num = 0;
+
+ /* Convenient for info fork, saves having to actually switch
+ contexts. */
+ readonly_detached_regcache *savedregs = nullptr;
+
+ CORE_ADDR pc = 0;
+
+ /* True if we should restore saved regs. */
+ int clobber_regs = 0;
+
+ /* Set of open file descriptors' offsets. */
+ off_t *filepos = nullptr;
+
+ int maxfd = 0;
};
+static std::list<fork_info> fork_list;
+static int highest_fork_num;
+
/* Fork list methods: */
int
forks_exist_p (void)
{
- return (fork_list != NULL);
+ return !fork_list.empty ();
}
/* Return the last fork in the list. */
@@ -66,26 +102,19 @@ forks_exist_p (void)
static struct fork_info *
find_last_fork (void)
{
- struct fork_info *last;
-
- if (fork_list == NULL)
+ if (fork_list.empty ())
return NULL;
- for (last = fork_list; last->next != NULL; last = last->next)
- ;
- return last;
+ return &fork_list.back ();
}
-/* Allocate a new fork. */
+/* Return true iff there's one fork in the list. */
-static struct fork_info *
-new_fork (pid_t pid)
+static bool
+one_fork_p ()
{
- struct fork_info *fp;
-
- fp = XCNEW (struct fork_info);
- fp->ptid = ptid_t (pid, pid, 0);
- return fp;
+ return (!fork_list.empty ()
+ && &fork_list.front () == &fork_list.back ());
}
/* Add a new fork to the internal fork list. */
@@ -93,93 +122,46 @@ new_fork (pid_t pid)
void
add_fork (pid_t pid)
{
- struct fork_info *fp = new_fork (pid);
-
- if (fork_list == NULL)
- {
- fork_list = fp;
- highest_fork_num = 0;
- }
- else
- {
- struct fork_info *last = find_last_fork ();
+ fork_list.emplace_back (pid);
- last->next = fp;
- }
+ if (one_fork_p ())
+ highest_fork_num = 0;
+ fork_info *fp = &fork_list.back ();
fp->num = ++highest_fork_num;
}
-static void
-free_fork (struct fork_info *fp)
-{
- /* Notes on step-resume breakpoints: since this is a concern for
- threads, let's convince ourselves that it's not a concern for
- forks. There are two ways for a fork_info to be created. First,
- by the checkpoint command, in which case we're at a gdb prompt
- and there can't be any step-resume breakpoint. Second, by a fork
- in the user program, in which case we *may* have stepped into the
- fork call, but regardless of whether we follow the parent or the
- child, we will return to the same place and the step-resume
- breakpoint, if any, will take care of itself as usual. And
- unlike threads, we do not save a private copy of the step-resume
- breakpoint -- so we're OK. */
-
- if (fp)
- {
- if (fp->savedregs)
- delete fp->savedregs;
- if (fp->filepos)
- xfree (fp->filepos);
- xfree (fp);
- }
-}
-
static void
delete_fork (ptid_t ptid)
{
- struct fork_info *fp, *fpprev;
-
- fpprev = NULL;
-
linux_target->low_forget_process (ptid.pid ());
- for (fp = fork_list; fp; fpprev = fp, fp = fp->next)
- if (fp->ptid == ptid)
- break;
-
- if (!fp)
- return;
-
- if (fpprev)
- fpprev->next = fp->next;
- else
- fork_list = fp->next;
-
- free_fork (fp);
+ for (auto it = fork_list.begin (); it != fork_list.end (); ++it)
+ if (it->ptid == ptid)
+ {
+ fork_list.erase (it);
- /* Special case: if there is now only one process in the list,
- and if it is (hopefully!) the current inferior_ptid, then
- remove it, leaving the list empty -- we're now down to the
- default case of debugging a single process. */
- if (fork_list != NULL && fork_list->next == NULL &&
- fork_list->ptid == inferior_ptid)
- {
- /* Last fork -- delete from list and handle as solo process
- (should be a safe recursion). */
- delete_fork (inferior_ptid);
- }
+ /* Special case: if there is now only one process in the list,
+ and if it is (hopefully!) the current inferior_ptid, then
+ remove it, leaving the list empty -- we're now down to the
+ default case of debugging a single process. */
+ if (one_fork_p () && fork_list.front ().ptid == inferior_ptid)
+ {
+ /* Last fork -- delete from list and handle as solo
+ process (should be a safe recursion). */
+ delete_fork (inferior_ptid);
+ }
+ return;
+ }
}
/* Find a fork_info by matching PTID. */
static struct fork_info *
find_fork_ptid (ptid_t ptid)
{
- struct fork_info *fp;
-
- for (fp = fork_list; fp; fp = fp->next)
- if (fp->ptid == ptid)
- return fp;
+ for (fork_info &fi : fork_list)
+ if (fi.ptid == ptid)
+ return &fi;
return NULL;
}
@@ -188,11 +170,9 @@ find_fork_ptid (ptid_t ptid)
static struct fork_info *
find_fork_id (int num)
{
- struct fork_info *fp;
-
- for (fp = fork_list; fp; fp = fp->next)
- if (fp->num == num)
- return fp;
+ for (fork_info &fi : fork_list)
+ if (fi.num == num)
+ return &fi;
return NULL;
}
@@ -201,11 +181,9 @@ find_fork_id (int num)
extern struct fork_info *
find_fork_pid (pid_t pid)
{
- struct fork_info *fp;
-
- for (fp = fork_list; fp; fp = fp->next)
- if (pid == fp->ptid.pid ())
- return fp;
+ for (fork_info &fi : fork_list)
+ if (pid == fi.ptid.pid ())
+ return &fi;
return NULL;
}
@@ -220,23 +198,6 @@ fork_id_to_ptid (int num)
return ptid_t (-1);
}
-static void
-init_fork_list (void)
-{
- struct fork_info *fp, *fpnext;
-
- if (!fork_list)
- return;
-
- for (fp = fork_list; fp; fp = fpnext)
- {
- fpnext = fp->next;
- free_fork (fp);
- }
-
- fork_list = NULL;
-}
-
/* Fork list <-> gdb interface. */
/* Utility function for fork_load/fork_save.
@@ -350,13 +311,12 @@ linux_fork_killall (void)
status for it) -- however any process may be a child
or a parent, so may get a SIGCHLD from a previously
killed child. Wait them all out. */
- struct fork_info *fp;
- pid_t pid, ret;
- int status;
- for (fp = fork_list; fp; fp = fp->next)
+ for (fork_info &fi : fork_list)
{
- pid = fp->ptid.pid ();
+ pid_t pid = fi.ptid.pid ();
+ int status;
+ pid_t ret;
do {
/* Use SIGKILL instead of PTRACE_KILL because the former works even
if the thread is running, while the later doesn't. */
@@ -367,7 +327,9 @@ linux_fork_killall (void)
died. MVS comment cut-and-pasted from linux-nat. */
} while (ret == pid && WIFSTOPPED (status));
}
- init_fork_list (); /* Clear list, prepare to start fresh. */
+
+ /* Clear list, prepare to start fresh. */
+ fork_list.clear ();
}
/* The current inferior_ptid has exited, but there are other viable
@@ -394,7 +356,7 @@ linux_fork_mourn_inferior (void)
/* There should still be a fork - if there's only one left,
delete_fork won't remove it, because we haven't updated
inferior_ptid yet. */
- gdb_assert (fork_list);
+ gdb_assert (!fork_list.empty ());
last = find_last_fork ();
fork_load_infrun_state (last);
@@ -402,7 +364,7 @@ linux_fork_mourn_inferior (void)
target_pid_to_str (inferior_ptid));
/* If there's only one fork, switch back to non-fork mode. */
- if (fork_list->next == NULL)
+ if (one_fork_p ())
delete_fork (inferior_ptid);
}
@@ -425,16 +387,16 @@ linux_fork_detach (int from_tty)
/* There should still be a fork - if there's only one left,
delete_fork won't remove it, because we haven't updated
inferior_ptid yet. */
- gdb_assert (fork_list);
+ gdb_assert (!fork_list.empty ());
- fork_load_infrun_state (fork_list);
+ fork_load_infrun_state (&fork_list.front ());
if (from_tty)
printf_filtered (_("[Switching to %s]\n"),
target_pid_to_str (inferior_ptid));
/* If there's only one fork, switch back to non-fork mode. */
- if (fork_list->next == NULL)
+ if (one_fork_p ())
delete_fork (inferior_ptid);
}
@@ -606,34 +568,31 @@ static void
info_checkpoints_command (const char *arg, int from_tty)
{
struct gdbarch *gdbarch = get_current_arch ();
- struct symtab_and_line sal;
- struct fork_info *fp;
- ULONGEST pc;
int requested = -1;
- struct fork_info *printed = NULL;
+ const fork_info *printed = NULL;
if (arg && *arg)
requested = (int) parse_and_eval_long (arg);
- for (fp = fork_list; fp; fp = fp->next)
+ for (const fork_info &fi : fork_list)
{
- if (requested > 0 && fp->num != requested)
+ if (requested > 0 && fi.num != requested)
continue;
- printed = fp;
- if (fp->ptid == inferior_ptid)
+ printed = &fi;
+ if (fi.ptid == inferior_ptid)
printf_filtered ("* ");
else
printf_filtered (" ");
- pc = fp->pc;
- printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid));
- if (fp->num == 0)
+ ULONGEST pc = fi.pc;
+ printf_filtered ("%d %s", fi.num, target_pid_to_str (fi.ptid));
+ if (fi.num == 0)
printf_filtered (_(" (main process)"));
printf_filtered (_(" at "));
fputs_filtered (paddress (gdbarch, pc), gdb_stdout);
- sal = find_pc_line (pc, 0);
+ symtab_and_line sal = find_pc_line (pc, 0);
if (sal.symtab)
printf_filtered (_(", file %s"),
symtab_to_filename_for_display (sal.symtab));
@@ -762,14 +721,12 @@ checkpoint_command (const char *args, int from_tty)
if (!fp)
error (_("Failed to find new fork"));
- if (fork_list->next == NULL)
+ if (one_fork_p ())
{
/* Special case -- if this is the first fork in the list (the
list was hitherto empty), then add inferior_ptid first, as a
special zeroeth fork id. */
- fork_info *first = new_fork (inferior_ptid.pid ());
- first->next = fork_list;
- fork_list = first;
+ fork_list.emplace_front (inferior_ptid.pid ());
}
fork_save_infrun_state (fp, 1);
@@ -816,8 +773,6 @@ restart_command (const char *args, int from_tty)
void
_initialize_linux_fork (void)
{
- init_fork_list ();
-
/* Checkpoint command: create a fork of the inferior process
and set it aside for later debugging. */