X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=gdb%2Fravenscar-thread.c;h=30745f7caacc03f8b0f37b7aa12266e92d1e7636;hb=3b1b69bffe522f22d269723856d2caa901041819;hp=d150412005bc3f92b12edb40de7a12b74a660f9b;hpb=3b7344d5ab495cd82b6c72ec5e00d018549837fb;p=thirdparty%2Fbinutils-gdb.git

diff --git a/gdb/ravenscar-thread.c b/gdb/ravenscar-thread.c
index d150412005b..30745f7caac 100644
--- a/gdb/ravenscar-thread.c
+++ b/gdb/ravenscar-thread.c
@@ -1,6 +1,6 @@
 /* Ada Ravenscar thread support.
 
-   Copyright (C) 2004-2014 Free Software Foundation, Inc.
+   Copyright (C) 2004-2017 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -26,10 +26,36 @@
 #include "command.h"
 #include "ravenscar-thread.h"
 #include "observer.h"
-#include <string.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;
@@ -37,11 +63,9 @@ static int ravenscar_task_support = 1;
 /* 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";
@@ -52,10 +76,10 @@ static const char first_task_name[] = "system__tasking__debug__first_task";
 static const char ravenscar_runtime_initializer[] =
   "system__bb__threads__initialize";
 
-static void ravenscar_find_new_threads (struct target_ops *ops);
-static ptid_t ravenscar_running_thread (void);
-static char *ravenscar_extra_thread_info (struct target_ops *self,
-					  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);
@@ -72,26 +96,110 @@ static int ravenscar_runtime_initialized (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);
@@ -144,14 +252,14 @@ has_ravenscar_runtime (void)
 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)
 {
   struct bound_minimal_symbol object_msym = get_running_thread_msymbol ();
   int object_size;
@@ -164,10 +272,11 @@ get_running_thread_id (void)
   if (!object_msym.minsym)
     return 0;
 
-  object_addr = MSYMBOL_VALUE_ADDRESS (object_msym.minsym);
   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);
 }
@@ -188,9 +297,10 @@ ravenscar_wait (struct target_ops *ops, ptid_t ptid,
                 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);
+  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.
 
@@ -201,7 +311,8 @@ ravenscar_wait (struct target_ops *ops, ptid_t ptid,
   if (status->kind != TARGET_WAITKIND_EXITED
       && status->kind != TARGET_WAITKIND_SIGNALLED)
     {
-      ravenscar_find_new_threads (ops);
+      inferior_ptid = event_ptid;
+      ravenscar_update_thread_list (ops);
       ravenscar_update_inferior_ptid ();
     }
   return inferior_ptid;
@@ -218,7 +329,7 @@ ravenscar_add_thread (struct ada_task_info *task)
 }
 
 static void
-ravenscar_find_new_threads (struct target_ops *ops)
+ravenscar_update_thread_list (struct target_ops *ops)
 {
   ada_build_task_list ();
 
@@ -231,9 +342,9 @@ ravenscar_find_new_threads (struct target_ops *ops)
 }
 
 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;
@@ -241,7 +352,7 @@ ravenscar_running_thread (void)
     return ptid_build (ptid_get_pid (base_ptid), 0, tid);
 }
 
-static char *
+static const char *
 ravenscar_extra_thread_info (struct target_ops *self, struct thread_info *tp)
 {
   return "Ravenscar task";
@@ -254,7 +365,7 @@ ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid)
   return 1;
 }
 
-static char *
+static const char *
 ravenscar_pid_to_str (struct target_ops *ops, ptid_t ptid)
 {
   static char buf[30];
@@ -268,19 +379,20 @@ ravenscar_fetch_registers (struct target_ops *ops,
                            struct regcache *regcache, int regnum)
 {
   struct target_ops *beneath = find_target_beneath (ops);
+  ptid_t ptid = regcache_get_ptid (regcache);
 
-  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);
-  else
+  if (ravenscar_runtime_initialized ()
+      && is_ravenscar_task (ptid)
+      && !ravenscar_task_is_currently_active (ptid))
     {
-      struct gdbarch *gdbarch = get_regcache_arch (regcache);
+      struct gdbarch *gdbarch = regcache->arch ();
       struct ravenscar_arch_ops *arch_ops
 	= gdbarch_ravenscar_ops (gdbarch);
 
       arch_ops->to_fetch_registers (regcache, regnum);
     }
+  else
+    beneath->to_fetch_registers (beneath, regcache, regnum);
 }
 
 static void
@@ -288,64 +400,147 @@ ravenscar_store_registers (struct target_ops *ops,
                            struct regcache *regcache, int regnum)
 {
   struct target_ops *beneath = find_target_beneath (ops);
+  ptid_t ptid = regcache_get_ptid (regcache);
 
-  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);
-  else
+  if (ravenscar_runtime_initialized ()
+      && is_ravenscar_task (ptid)
+      && !ravenscar_task_is_currently_active (ptid))
     {
-      struct gdbarch *gdbarch = get_regcache_arch (regcache);
+      struct gdbarch *gdbarch = regcache->arch ();
       struct ravenscar_arch_ops *arch_ops
 	= gdbarch_ravenscar_ops (gdbarch);
 
       arch_ops->to_store_registers (regcache, regnum);
     }
+  else
+    beneath->to_store_registers (beneath, regcache, regnum);
 }
 
 static void
 ravenscar_prepare_to_store (struct target_ops *self,
 			    struct regcache *regcache)
 {
-  struct target_ops *beneath = find_target_beneath (&ravenscar_ops);
+  struct target_ops *beneath = find_target_beneath (self);
+  ptid_t ptid = regcache_get_ptid (regcache);
 
-  if (!ravenscar_runtime_initialized ()
-      || ptid_equal (inferior_ptid, base_magic_null_ptid)
-      || ptid_equal (inferior_ptid, ravenscar_running_thread ()))
-    beneath->to_prepare_to_store (beneath, regcache);
-  else
+  if (ravenscar_runtime_initialized ()
+      && is_ravenscar_task (ptid)
+      && !ravenscar_task_is_currently_active (ptid))
     {
-      struct gdbarch *gdbarch = get_regcache_arch (regcache);
+      struct gdbarch *gdbarch = regcache->arch ();
       struct ravenscar_arch_ops *arch_ops
 	= gdbarch_ravenscar_ops (gdbarch);
 
       arch_ops->to_prepare_to_store (regcache);
     }
+  else
+    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);
 }
 
+/* Implement the to_core_of_thread target_ops "method".  */
+
+static int
+ravenscar_core_of_thread (struct target_ops *ops, ptid_t ptid)
+{
+  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_core_of_thread (beneath, inferior_ptid);
+  inferior_ptid = saved_ptid;
+  return result;
+}
+
 /* Observer on inferior_created: push ravenscar thread stratum if needed.  */
 
 static void
 ravenscar_inferior_created (struct target_ops *target, int from_tty)
 {
-  struct ravenscar_arch_ops *ops;
+  const char *err_msg;
 
   if (!ravenscar_task_support
-      || gdbarch_ravenscar_ops (current_inferior ()->gdbarch) == NULL
+      || 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.\n"), err_msg);
+      return;
+    }
+
   ravenscar_update_inferior_ptid ();
   push_target (&ravenscar_ops);
 }
@@ -367,8 +562,14 @@ init_ravenscar_thread_ops (void)
   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;
@@ -379,6 +580,7 @@ init_ravenscar_thread_ops (void)
   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;
 }
 
@@ -389,17 +591,17 @@ static struct cmd_list_element *show_ravenscar_list;
 /* 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, "");
 }
@@ -419,9 +621,6 @@ Support for Ravenscar task/thread switching is enabled\n"));
 Support for Ravenscar task/thread switching is disabled\n"));
 }
 
-/* Provide a prototype to silence -Wmissing-prototypes.  */
-extern void _initialize_ravenscar (void);
-
 /* Module startup initialization function, automagically called by
    init.c.  */