/* Ada Ravenscar thread support.
- Copyright 2004, 2009, 2010 Free Software Foundation, Inc.
+ Copyright (C) 2004-2018 Free Software Foundation, Inc.
This file is part of GDB.
#include "inferior.h"
#include "command.h"
#include "ravenscar-thread.h"
-#include "observer.h"
-#include "gdb_string.h"
+#include "observable.h"
#include "gdbcmd.h"
#include "top.h"
#include "regcache.h"
+#include "objfiles.h"
+
+/* This module provides support for "Ravenscar" tasks (Ada) when
+ debugging on bare-metal targets.
+
+ The typical situation is when debugging a bare-metal target over
+ the remote protocol. In that situation, the system does not know
+ about high-level comcepts such as threads, only about some code
+ running on one or more CPUs. And since the remote protocol does not
+ provide any handling for CPUs, the de facto standard for handling
+ them is to have one thread per CPU, where the thread's ptid has
+ its lwp field set to the CPU number (eg: 1 for the first CPU,
+ 2 for the second one, etc). This module will make that assumption.
+
+ This module then creates and maintains the list of threads based
+ on the list of Ada tasks, with one thread per Ada tasks. The convention
+ is that threads corresponding to the CPUs (see assumption above)
+ have a ptid_t of the form (PID, LWP, 0), which threads corresponding
+ to our Ada tasks have a ptid_t of the form (PID, 0, TID) where TID
+ is the Ada task's ID as extracted from Ada runtime information.
+
+ Switching to a given Ada tasks (or its underlying thread) is performed
+ by fetching the registers of that tasks from the memory area where
+ the registers were saved. For any of the other operations, the
+ operation is performed by first finding the CPU on which the task
+ is running, switching to its corresponding ptid, and then performing
+ the operation on that ptid using the target beneath us. */
/* If non-null, ravenscar task support is enabled. */
static int ravenscar_task_support = 1;
-/* Non-null if the ravenscar thread layer has been pushed on the target
- stack. */
-static int ravenscar_is_open = 0;
-
/* This module's target-specific operations. */
static struct target_ops ravenscar_ops;
-/* Some base target uses a special value for the null PID (exempli gratia
- remote). */
-static ptid_t base_magic_null_ptid;
-
-/* Ptid of the inferior as seen by the process stratum. */
+/* PTID of the last thread that received an event.
+ This can be useful to determine the associated task that received
+ the event, to make it the current task. */
static ptid_t base_ptid;
static const char running_thread_name[] = "__gnat_running_thread_table";
static const char known_tasks_name[] = "system__tasking__debug__known_tasks";
+static const char first_task_name[] = "system__tasking__debug__first_task";
-static const char ravenscar_runtime_initializer[] = "system__bb__threads__initialize";
-
-static struct observer *update_target_observer = NULL;
+static const char ravenscar_runtime_initializer[] =
+ "system__bb__threads__initialize";
-/* Architecture-specific hooks. */
-static struct ravenscar_arch_ops* current_arch_ops;
-
-static void ravenscar_find_new_threads (struct target_ops *ops);
-static ptid_t ravenscar_running_thread (void);
-static char *ravenscar_extra_thread_info (struct thread_info *tp);
+static void ravenscar_update_thread_list (struct target_ops *ops);
+static ptid_t ravenscar_active_task (int cpu);
+static const char *ravenscar_extra_thread_info (struct target_ops *self,
+ struct thread_info *tp);
static int ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid);
static void ravenscar_fetch_registers (struct target_ops *ops,
struct regcache *regcache, int regnum);
static void ravenscar_store_registers (struct target_ops *ops,
struct regcache *regcache, int regnum);
-static void ravenscar_prepare_to_store (struct regcache *regcache);
-static void ravenscar_initialize (char *name, int from_tty);
+static void ravenscar_prepare_to_store (struct target_ops *self,
+ struct regcache *regcache);
static void ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step,
- enum target_signal siggnal);
+ enum gdb_signal siggnal);
static void ravenscar_mourn_inferior (struct target_ops *ops);
static void ravenscar_update_inferior_ptid (void);
static int has_ravenscar_runtime (void);
static void ravenscar_inferior_created (struct target_ops *target,
int from_tty);
+/* Return nonzero iff PTID corresponds to a ravenscar task. */
+
+static int
+is_ravenscar_task (ptid_t ptid)
+{
+ /* By construction, ravenscar tasks have their LWP set to zero.
+ Also make sure that the TID is nonzero, as some remotes, when
+ asked for the list of threads, will return the first thread
+ as having its TID set to zero. For instance, TSIM version
+ 2.0.48 for LEON3 sends 'm0' as a reply to the 'qfThreadInfo'
+ query, which the remote protocol layer then treats as a thread
+ whose TID is 0. This is obviously not a ravenscar task. */
+ return ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) != 0;
+}
+
+/* Given PTID, which can be either a ravenscar task or a CPU thread,
+ return which CPU that ptid is running on.
+
+ This assume that PTID is a valid ptid_t. Otherwise, a gdb_assert
+ will be triggered. */
+
+static int
+ravenscar_get_thread_base_cpu (ptid_t ptid)
+{
+ int base_cpu;
+
+ if (is_ravenscar_task (ptid))
+ {
+ struct ada_task_info *task_info = ada_get_task_info_from_ptid (ptid);
+
+ gdb_assert (task_info != NULL);
+ base_cpu = task_info->base_cpu;
+ }
+ else
+ {
+ /* We assume that the LWP of the PTID is equal to the CPU number. */
+ base_cpu = ptid_get_lwp (ptid);
+ }
+
+ return base_cpu;
+}
+
+/* Given a ravenscar task (identified by its ptid_t PTID), return nonzero
+ if this task is the currently active task on the cpu that task is
+ running on.
+
+ In other words, this function determine which CPU this task is
+ currently running on, and then return nonzero if the CPU in question
+ is executing the code for that task. If that's the case, then
+ that task's registers are in the CPU bank. Otherwise, the task
+ is currently suspended, and its registers have been saved in memory. */
+
+static int
+ravenscar_task_is_currently_active (ptid_t ptid)
+{
+ ptid_t active_task_ptid
+ = ravenscar_active_task (ravenscar_get_thread_base_cpu (ptid));
+
+ return ptid_equal (ptid, active_task_ptid);
+}
+
+/* Return the CPU thread (as a ptid_t) on which the given ravenscar
+ task is running.
+
+ This is the thread that corresponds to the CPU on which the task
+ is running. */
+
+static ptid_t
+get_base_thread_from_ravenscar_task (ptid_t ptid)
+{
+ int base_cpu;
+
+ if (!is_ravenscar_task (ptid))
+ return ptid;
+
+ base_cpu = ravenscar_get_thread_base_cpu (ptid);
+ return ptid_build (ptid_get_pid (ptid), base_cpu, 0);
+}
+
/* Fetch the ravenscar running thread from target memory and
update inferior_ptid accordingly. */
static void
ravenscar_update_inferior_ptid (void)
{
+ int base_cpu;
+
base_ptid = inferior_ptid;
+ gdb_assert (!is_ravenscar_task (inferior_ptid));
+ base_cpu = ravenscar_get_thread_base_cpu (base_ptid);
+
/* If the runtime has not been initialized yet, the inferior_ptid is
the only ptid that there is. */
if (!ravenscar_runtime_initialized ())
return;
- /* Make sure we set base_ptid before calling ravenscar_running_thread
+ /* Make sure we set base_ptid before calling ravenscar_active_task
as the latter relies on it. */
- inferior_ptid = ravenscar_running_thread ();
+ inferior_ptid = ravenscar_active_task (base_cpu);
gdb_assert (!ptid_equal (inferior_ptid, null_ptid));
/* The running thread may not have been added to
- system.tasking.debug's list yet; so ravenscar_find_new_threads
+ system.tasking.debug's list yet; so ravenscar_update_thread_list
may not always add it to the thread list. Add it here. */
if (!find_thread_ptid (inferior_ptid))
add_thread (inferior_ptid);
and return its associated minimal symbol.
Return NULL if not found. */
-static struct minimal_symbol *
+static struct bound_minimal_symbol
get_running_thread_msymbol (void)
{
- struct minimal_symbol *msym;
+ struct bound_minimal_symbol msym;
msym = lookup_minimal_symbol (running_thread_name, NULL, NULL);
- if (!msym)
+ if (!msym.minsym)
/* Older versions of the GNAT runtime were using a different
(less ideal) name for the symbol where the active thread ID
is stored. If we couldn't find the symbol using the latest
static int
has_ravenscar_runtime (void)
{
- struct minimal_symbol *msym_ravenscar_runtime_initializer =
+ struct bound_minimal_symbol msym_ravenscar_runtime_initializer =
lookup_minimal_symbol (ravenscar_runtime_initializer, NULL, NULL);
- struct minimal_symbol *msym_known_tasks =
+ struct bound_minimal_symbol msym_known_tasks =
lookup_minimal_symbol (known_tasks_name, NULL, NULL);
- struct minimal_symbol *msym_running_thread = get_running_thread_msymbol ();
-
- return (msym_ravenscar_runtime_initializer
- && msym_known_tasks
- && msym_running_thread);
+ struct bound_minimal_symbol msym_first_task =
+ lookup_minimal_symbol (first_task_name, NULL, NULL);
+ struct bound_minimal_symbol msym_running_thread
+ = get_running_thread_msymbol ();
+
+ return (msym_ravenscar_runtime_initializer.minsym
+ && (msym_known_tasks.minsym || msym_first_task.minsym)
+ && msym_running_thread.minsym);
}
/* Return True if the Ada Ravenscar run-time can be found in the
static int
ravenscar_runtime_initialized (void)
{
- return (!(ptid_equal (ravenscar_running_thread (), null_ptid)));
+ return (!(ptid_equal (ravenscar_active_task (1), null_ptid)));
}
/* Return the ID of the thread that is currently running.
Return 0 if the ID could not be determined. */
static CORE_ADDR
-get_running_thread_id (void)
+get_running_thread_id (int cpu)
{
- const struct minimal_symbol *object_msym = get_running_thread_msymbol ();
+ struct bound_minimal_symbol object_msym = get_running_thread_msymbol ();
int object_size;
int buf_size;
- char *buf;
+ gdb_byte *buf;
CORE_ADDR object_addr;
struct type *builtin_type_void_data_ptr =
- builtin_type (target_gdbarch)->builtin_data_ptr;
+ builtin_type (target_gdbarch ())->builtin_data_ptr;
- if (!object_msym)
+ if (!object_msym.minsym)
return 0;
- object_addr = SYMBOL_VALUE_ADDRESS (object_msym);
object_size = TYPE_LENGTH (builtin_type_void_data_ptr);
+ object_addr = (BMSYMBOL_VALUE_ADDRESS (object_msym)
+ + (cpu - 1) * object_size);
buf_size = object_size;
- buf = alloca (buf_size);
+ buf = (gdb_byte *) alloca (buf_size);
read_memory (object_addr, buf, buf_size);
return extract_typed_address (buf, builtin_type_void_data_ptr);
}
-static void
-ravenscar_close (int quitting)
-{
- ravenscar_is_open = 0;
-}
-
static void
ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step,
- enum target_signal siggnal)
+ enum gdb_signal siggnal)
{
struct target_ops *beneath = find_target_beneath (ops);
int options)
{
struct target_ops *beneath = find_target_beneath (ops);
+ ptid_t event_ptid;
inferior_ptid = base_ptid;
- beneath->to_wait (beneath, base_ptid, status, 0);
- ravenscar_find_new_threads (ops);
- ravenscar_update_inferior_ptid ();
+ event_ptid = beneath->to_wait (beneath, base_ptid, status, 0);
+ /* Find any new threads that might have been created, and update
+ inferior_ptid to the active thread.
+
+ Only do it if the program is still alive, though. Otherwise,
+ this causes problems when debugging through the remote protocol,
+ because we might try switching threads (and thus sending packets)
+ after the remote has disconnected. */
+ if (status->kind != TARGET_WAITKIND_EXITED
+ && status->kind != TARGET_WAITKIND_SIGNALLED)
+ {
+ inferior_ptid = event_ptid;
+ ravenscar_update_thread_list (ops);
+ ravenscar_update_inferior_ptid ();
+ }
return inferior_ptid;
}
}
static void
-ravenscar_find_new_threads (struct target_ops *ops)
+ravenscar_update_thread_list (struct target_ops *ops)
{
- ada_build_task_list (0);
+ ada_build_task_list ();
/* Do not clear the thread list before adding the Ada task, to keep
the thread that the process stratum has included into it
}
static ptid_t
-ravenscar_running_thread (void)
+ravenscar_active_task (int cpu)
{
- CORE_ADDR tid = get_running_thread_id ();
+ CORE_ADDR tid = get_running_thread_id (cpu);
if (tid == 0)
return null_ptid;
return ptid_build (ptid_get_pid (base_ptid), 0, tid);
}
-static char *
-ravenscar_extra_thread_info (struct thread_info *tp)
+static const char *
+ravenscar_extra_thread_info (struct target_ops *self, struct thread_info *tp)
{
return "Ravenscar task";
}
return 1;
}
-static char *
+static const char *
ravenscar_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
static char buf[30];
struct regcache *regcache, int regnum)
{
struct target_ops *beneath = find_target_beneath (ops);
-
- if (!ravenscar_runtime_initialized ()
- || ptid_equal (inferior_ptid, base_magic_null_ptid)
- || ptid_equal (inferior_ptid, ravenscar_running_thread ()))
- beneath->to_fetch_registers (beneath, regcache, regnum);
+ ptid_t ptid = regcache_get_ptid (regcache);
+
+ if (ravenscar_runtime_initialized ()
+ && is_ravenscar_task (ptid)
+ && !ravenscar_task_is_currently_active (ptid))
+ {
+ struct gdbarch *gdbarch = regcache->arch ();
+ struct ravenscar_arch_ops *arch_ops
+ = gdbarch_ravenscar_ops (gdbarch);
+
+ arch_ops->to_fetch_registers (regcache, regnum);
+ }
else
- current_arch_ops->to_fetch_registers (regcache, regnum);
+ beneath->to_fetch_registers (beneath, regcache, regnum);
}
static void
struct regcache *regcache, int regnum)
{
struct target_ops *beneath = find_target_beneath (ops);
-
- if (!ravenscar_runtime_initialized ()
- || ptid_equal (inferior_ptid, base_magic_null_ptid)
- || ptid_equal (inferior_ptid, ravenscar_running_thread ()))
- beneath->to_store_registers (beneath, regcache, regnum);
+ ptid_t ptid = regcache_get_ptid (regcache);
+
+ if (ravenscar_runtime_initialized ()
+ && is_ravenscar_task (ptid)
+ && !ravenscar_task_is_currently_active (ptid))
+ {
+ struct gdbarch *gdbarch = regcache->arch ();
+ struct ravenscar_arch_ops *arch_ops
+ = gdbarch_ravenscar_ops (gdbarch);
+
+ arch_ops->to_store_registers (regcache, regnum);
+ }
else
- current_arch_ops->to_store_registers (regcache, regnum);
+ beneath->to_store_registers (beneath, regcache, regnum);
}
static void
-ravenscar_prepare_to_store (struct regcache *regcache)
+ravenscar_prepare_to_store (struct target_ops *self,
+ struct regcache *regcache)
{
- struct target_ops *beneath = find_target_beneath (&ravenscar_ops);
-
- if (!ravenscar_runtime_initialized ()
- || ptid_equal (inferior_ptid, base_magic_null_ptid)
- || ptid_equal (inferior_ptid, ravenscar_running_thread ()))
- beneath->to_prepare_to_store (regcache);
+ struct target_ops *beneath = find_target_beneath (self);
+ ptid_t ptid = regcache_get_ptid (regcache);
+
+ if (ravenscar_runtime_initialized ()
+ && is_ravenscar_task (ptid)
+ && !ravenscar_task_is_currently_active (ptid))
+ {
+ struct gdbarch *gdbarch = regcache->arch ();
+ struct ravenscar_arch_ops *arch_ops
+ = gdbarch_ravenscar_ops (gdbarch);
+
+ arch_ops->to_prepare_to_store (regcache);
+ }
else
- current_arch_ops->to_prepare_to_store (regcache);
+ beneath->to_prepare_to_store (beneath, regcache);
+}
+
+/* Implement the to_stopped_by_sw_breakpoint target_ops "method". */
+
+static int
+ravenscar_stopped_by_sw_breakpoint (struct target_ops *ops)
+{
+ ptid_t saved_ptid = inferior_ptid;
+ struct target_ops *beneath = find_target_beneath (ops);
+ int result;
+
+ inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
+ result = beneath->to_stopped_by_sw_breakpoint (beneath);
+ inferior_ptid = saved_ptid;
+ return result;
+}
+
+/* Implement the to_stopped_by_hw_breakpoint target_ops "method". */
+
+static int
+ravenscar_stopped_by_hw_breakpoint (struct target_ops *ops)
+{
+ ptid_t saved_ptid = inferior_ptid;
+ struct target_ops *beneath = find_target_beneath (ops);
+ int result;
+
+ inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
+ result = beneath->to_stopped_by_hw_breakpoint (beneath);
+ inferior_ptid = saved_ptid;
+ return result;
+}
+
+/* Implement the to_stopped_by_watchpoint target_ops "method". */
+
+static int
+ravenscar_stopped_by_watchpoint (struct target_ops *ops)
+{
+ ptid_t saved_ptid = inferior_ptid;
+ struct target_ops *beneath = find_target_beneath (ops);
+ int result;
+
+ inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
+ result = beneath->to_stopped_by_watchpoint (beneath);
+ inferior_ptid = saved_ptid;
+ return result;
+}
+
+/* Implement the to_stopped_data_address target_ops "method". */
+
+static int
+ravenscar_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
+{
+ ptid_t saved_ptid = inferior_ptid;
+ struct target_ops *beneath = find_target_beneath (ops);
+ int result;
+
+ inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
+ result = beneath->to_stopped_data_address (beneath, addr_p);
+ inferior_ptid = saved_ptid;
+ return result;
}
static void
ravenscar_mourn_inferior (struct target_ops *ops)
{
- struct target_ops *beneath = find_target_beneath (&ravenscar_ops);
+ struct target_ops *beneath = find_target_beneath (ops);
base_ptid = null_ptid;
beneath->to_mourn_inferior (beneath);
unpush_target (&ravenscar_ops);
}
-/* Observer on inferior_created: push ravenscar thread stratum if needed. */
+/* Implement the to_core_of_thread target_ops "method". */
-static void
-ravenscar_inferior_created (struct target_ops *target, int from_tty)
+static int
+ravenscar_core_of_thread (struct target_ops *ops, ptid_t ptid)
{
- if (ravenscar_task_support
- && has_ravenscar_runtime ())
- ravenscar_initialize (NULL, 0);
-}
+ ptid_t saved_ptid = inferior_ptid;
+ struct target_ops *beneath = find_target_beneath (ops);
+ int result;
-void
-ravenscar_register_arch_ops (struct ravenscar_arch_ops *ops)
-{
- /* FIXME: To be clean, we would need to handle a list of
- architectures, just like in remote-wtx-hw.c. However, for now the
- only Ravenscar run-time for bare board that is implemented in
- GNAT is for only one architecture: erc32-elf. So no need to care about
- that for now...*/
- current_arch_ops = ops;
+ inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
+ result = beneath->to_core_of_thread (beneath, inferior_ptid);
+ inferior_ptid = saved_ptid;
+ return result;
}
-/* Initialize Ravenscar support. */
+/* Observer on inferior_created: push ravenscar thread stratum if needed. */
static void
-ravenscar_initialize (char *name, int from_tty)
+ravenscar_inferior_created (struct target_ops *target, int from_tty)
{
- if (ravenscar_is_open)
+ const char *err_msg;
+
+ if (!ravenscar_task_support
+ || gdbarch_ravenscar_ops (target_gdbarch ()) == NULL
+ || !has_ravenscar_runtime ())
return;
- base_magic_null_ptid = inferior_ptid;
+ err_msg = ada_get_tcb_types_info ();
+ if (err_msg != NULL)
+ {
+ warning (_("%s. Task/thread support disabled."), err_msg);
+ return;
+ }
+
ravenscar_update_inferior_ptid ();
push_target (&ravenscar_ops);
- ravenscar_is_open = 1;
}
static ptid_t
-ravenscar_get_ada_task_ptid (long lwp, long thread)
+ravenscar_get_ada_task_ptid (struct target_ops *self, long lwp, long thread)
{
return ptid_build (ptid_get_pid (base_ptid), 0, thread);
}
ravenscar_ops.to_shortname = "ravenscar";
ravenscar_ops.to_longname = "Ravenscar tasks.";
ravenscar_ops.to_doc = "Ravenscar tasks support.";
- ravenscar_ops.to_close = ravenscar_close;
ravenscar_ops.to_resume = ravenscar_resume;
ravenscar_ops.to_wait = ravenscar_wait;
ravenscar_ops.to_fetch_registers = ravenscar_fetch_registers;
ravenscar_ops.to_store_registers = ravenscar_store_registers;
ravenscar_ops.to_prepare_to_store = ravenscar_prepare_to_store;
+ ravenscar_ops.to_stopped_by_sw_breakpoint
+ = ravenscar_stopped_by_sw_breakpoint;
+ ravenscar_ops.to_stopped_by_hw_breakpoint
+ = ravenscar_stopped_by_hw_breakpoint;
+ ravenscar_ops.to_stopped_by_watchpoint = ravenscar_stopped_by_watchpoint;
+ ravenscar_ops.to_stopped_data_address = ravenscar_stopped_data_address;
ravenscar_ops.to_thread_alive = ravenscar_thread_alive;
- ravenscar_ops.to_find_new_threads = ravenscar_find_new_threads;
+ ravenscar_ops.to_update_thread_list = ravenscar_update_thread_list;
ravenscar_ops.to_pid_to_str = ravenscar_pid_to_str;
ravenscar_ops.to_extra_thread_info = ravenscar_extra_thread_info;
ravenscar_ops.to_get_ada_task_ptid = ravenscar_get_ada_task_ptid;
ravenscar_ops.to_has_registers = default_child_has_registers;
ravenscar_ops.to_has_execution = default_child_has_execution;
ravenscar_ops.to_stratum = thread_stratum;
+ ravenscar_ops.to_core_of_thread = ravenscar_core_of_thread;
ravenscar_ops.to_magic = OPS_MAGIC;
}
/* Implement the "set ravenscar" prefix command. */
static void
-set_ravenscar_command (char *arg, int from_tty)
+set_ravenscar_command (const char *arg, int from_tty)
{
printf_unfiltered (_(\
"\"set ravenscar\" must be followed by the name of a setting.\n"));
- help_list (set_ravenscar_list, "set ravenscar ", -1, gdb_stdout);
+ help_list (set_ravenscar_list, "set ravenscar ", all_commands, gdb_stdout);
}
/* Implement the "show ravenscar" prefix command. */
static void
-show_ravenscar_command (char *args, int from_tty)
+show_ravenscar_command (const char *args, int from_tty)
{
cmd_show_list (show_ravenscar_list, from_tty, "");
}
/* Notice when the inferior is created in order to push the
ravenscar ops if needed. */
- observer_attach_inferior_created (ravenscar_inferior_created);
+ gdb::observers::inferior_created.attach (ravenscar_inferior_created);
- add_target (&ravenscar_ops);
+ complete_target_initialization (&ravenscar_ops);
add_prefix_cmd ("ravenscar", no_class, set_ravenscar_command,
_("Prefix command for changing Ravenscar-specific settings"),