* mips-linux-tdep.c: Adjust formatting throughout.

[deliverable/binutils-gdb.git] / gdb / dummy-frame.c

diff --git a/gdb/dummy-frame.c b/gdb/dummy-frame.c
index 0a3e35e0d950b9961cb56b8986bff2793e3a6bec..390a6d86bd430e29f3409c9dae68c57ff902cb6b 100644 (file)
--- a/gdb/dummy-frame.c
+++ b/gdb/dummy-frame.c
@@ -1,14 +1,12 @@
 /* Code dealing with dummy stack frames, for GDB, the GNU debugger.
 
 /* Code dealing with dummy stack frames, for GDB, the GNU debugger.
 

-   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
-   1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software
-   Foundation, Inc.
+   Copyright (C) 1986-2013 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
 
    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 2 of the License, or
+   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,
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,


@@ -17,9 +15,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    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, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 
 #include "defs.h"
 
 
 #include "defs.h"


@@ -29,6 +25,11 @@
 #include "inferior.h"
 #include "gdb_assert.h"
 #include "frame-unwind.h"
 #include "inferior.h"
 #include "gdb_assert.h"
 #include "frame-unwind.h"

+#include "command.h"
+#include "gdbcmd.h"
+#include "gdb_string.h"
+#include "observer.h"
+#include "gdbthread.h"

 
 /* Dummy frame.  This saves the processor state just prior to setting
    up the inferior function call.  Older targets save the registers
 
 /* Dummy frame.  This saves the processor state just prior to setting
    up the inferior function call.  Older targets save the registers


@@ -37,350 +38,297 @@
 struct dummy_frame
 {
   struct dummy_frame *next;
 struct dummy_frame
 {
   struct dummy_frame *next;

-
-  /* These values belong to the caller (the previous frame, the frame
-     that this unwinds back to).  */
-  CORE_ADDR pc;
-  CORE_ADDR fp;
-  CORE_ADDR sp;
-  CORE_ADDR top;
+  /* This frame's ID.  Must match the value returned by
+     gdbarch_dummy_id.  */

   struct frame_id id;
   struct frame_id id;

-  struct regcache *regcache;
-
-  /* Address range of the call dummy code.  Look for PC in the range
-     [LO..HI) (after allowing for DECR_PC_AFTER_BREAK).  */
-  CORE_ADDR call_lo;
-  CORE_ADDR call_hi;
+  /* The caller's state prior to the call.  */
+  struct infcall_suspend_state *caller_state;

 };
 
 static struct dummy_frame *dummy_frame_stack = NULL;
 
 };
 
 static struct dummy_frame *dummy_frame_stack = NULL;
 

-/* Function: find_dummy_frame(pc, fp, sp)
-
-   Search the stack of dummy frames for one matching the given PC and
-   FP/SP.  Unlike pc_in_dummy_frame(), this function doesn't need to
-   adjust for DECR_PC_AFTER_BREAK.  This is because it is only legal
-   to call this function after the PC has been adjusted.  */
+/* Push the caller's state, along with the dummy frame info, onto the
+   dummy-frame stack.  */

 
 

-static struct dummy_frame *
-find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
+void
+dummy_frame_push (struct infcall_suspend_state *caller_state,
+                 const struct frame_id *dummy_id)

 {
 {

-  struct dummy_frame *dummyframe;
-
-  for (dummyframe = dummy_frame_stack; dummyframe != NULL;
-       dummyframe = dummyframe->next)
-    {
-      /* Does the PC fall within the dummy frame's breakpoint
-         instruction.  If not, discard this one.  */
-      if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
-       continue;
-      /* Does the FP match?  */
-      if (dummyframe->top != 0)
-       {
-         /* If the target architecture explicitly saved the
-            top-of-stack before the inferior function call, assume
-            that that same architecture will always pass in an FP
-            (frame base) value that eactly matches that saved TOS.
-            Don't check the saved SP and SP as they can lead to false
-            hits.  */
-         if (fp != dummyframe->top)
-           continue;
-       }
-      else
-       {
-         /* An older target that hasn't explicitly or implicitly
-             saved the dummy frame's top-of-stack.  Try matching the
-             FP against the saved SP and FP.  NOTE: If you're trying
-             to fix a problem with GDB not correctly finding a dummy
-             frame, check the comments that go with FRAME_ALIGN() and
-             SAVE_DUMMY_FRAME_TOS().  */
-         if (fp != dummyframe->fp && fp != dummyframe->sp)
-           continue;
-       }
-      /* The FP matches this dummy frame.  */
-      return dummyframe;
-    }
+  struct dummy_frame *dummy_frame;

 
 

-  return NULL;
+  dummy_frame = XZALLOC (struct dummy_frame);
+  dummy_frame->caller_state = caller_state;
+  dummy_frame->id = (*dummy_id);
+  dummy_frame->next = dummy_frame_stack;
+  dummy_frame_stack = dummy_frame;

 }
 
 }
 

-struct dummy_frame *
-cached_find_dummy_frame (struct frame_info *frame, void **cache)
-{
-  if ((*cache) == NULL)
-    (*cache) = find_dummy_frame (get_frame_pc (frame), get_frame_base (frame));
-  return (*cache);
-}
+/* Remove *DUMMY_PTR from the dummy frame stack.  */

 
 

-struct regcache *
-generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
+static void
+remove_dummy_frame (struct dummy_frame **dummy_ptr)

 {
 {

-  struct dummy_frame *dummy = find_dummy_frame (pc, fp);
-  if (dummy != NULL)
-    return dummy->regcache;
-  else
-    return NULL;
-}
+  struct dummy_frame *dummy = *dummy_ptr;

 
 

-char *
-deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
-{
-  struct regcache *regcache = generic_find_dummy_frame (pc, fp);
-  if (regcache == NULL)
-    return NULL;
-  return deprecated_grub_regcache_for_registers (regcache);
+  *dummy_ptr = dummy->next;
+  discard_infcall_suspend_state (dummy->caller_state);
+  xfree (dummy);

 }
 
 }
 

-/* Function: pc_in_call_dummy (pc, sp, fp)
+/* Delete any breakpoint B which is a momentary breakpoint for return from
+   inferior call matching DUMMY_VOIDP.  */

 
 

-   Return true if the PC falls in a dummy frame created by gdb for an
-   inferior call.  The code below which allows DECR_PC_AFTER_BREAK is
-   for infrun.c, which may give the function a PC without that
-   subtracted out.  */
-
-int
-generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
+static int
+pop_dummy_frame_bpt (struct breakpoint *b, void *dummy_voidp)

 {
 {

-  return pc_in_dummy_frame (pc);
-}
-
-/* Return non-zero if the PC falls in a dummy frame.
+  struct dummy_frame *dummy = dummy_voidp;

 
 

-   The code below which allows DECR_PC_AFTER_BREAK is for infrun.c,
-   which may give the function a PC without that subtracted out.
+  if (b->thread == pid_to_thread_id (inferior_ptid)
+      && b->disposition == disp_del && frame_id_eq (b->frame_id, dummy->id))
+    {
+      while (b->related_breakpoint != b)
+       delete_breakpoint (b->related_breakpoint);

 
 

-   FIXME: cagney/2002-11-23: This is silly.  Surely "infrun.c" can
-   figure out what the real PC (as in the resume address) is BEFORE
-   calling this function (Oh, and I'm not even sure that this function
-   is called with an decremented PC, the call to pc_in_call_dummy() in
-   that file is conditional on !CALL_DUMMY_BREAKPOINT_OFFSET_P yet
-   generic dummy targets set CALL_DUMMY_BREAKPOINT_OFFSET. True?).  */
+      delete_breakpoint (b);

 
 

-int
-pc_in_dummy_frame (CORE_ADDR pc)
-{
-  struct dummy_frame *dummyframe;
-  for (dummyframe = dummy_frame_stack;
-       dummyframe != NULL;
-       dummyframe = dummyframe->next)
-    {
-      if ((pc >= dummyframe->call_lo)
-         && (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
-       return 1;
+      /* Stop the traversal.  */
+      return 1;

     }
     }

+
+  /* Continue the traversal.  */

   return 0;
 }
 
   return 0;
 }
 

-/* Function: read_register_dummy 
-   Find a saved register from before GDB calls a function in the inferior */
+/* Pop *DUMMY_PTR, restoring program state to that before the
+   frame was created.  */

 
 

-CORE_ADDR
-deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
+static void
+pop_dummy_frame (struct dummy_frame **dummy_ptr)

 {
 {

-  struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
+  struct dummy_frame *dummy = *dummy_ptr;

 
 

-  if (dummy_regs)
-    {
-      /* NOTE: cagney/2002-08-12: Replaced a call to
-        regcache_raw_read_as_address() with a call to
-        regcache_cooked_read_unsigned().  The old, ...as_address
-        function was eventually calling extract_unsigned_integer (via
-        extract_address) to unpack the registers value.  The below is
-        doing an unsigned extract so that it is functionally
-        equivalent.  The read needs to be cooked as, otherwise, it
-        will never correctly return the value of a register in the
-        [NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range.  */
-      ULONGEST val;
-      regcache_cooked_read_unsigned (dummy_regs, regno, &val);
-      return val;
-    }
-  else
-    return 0;
-}
+  restore_infcall_suspend_state (dummy->caller_state);

 
 

-/* Save all the registers on the dummy frame stack.  Most ports save the
-   registers on the target stack.  This results in lots of unnecessary memory
-   references, which are slow when debugging via a serial line.  Instead, we
-   save all the registers internally, and never write them to the stack.  The
-   registers get restored when the called function returns to the entry point,
-   where a breakpoint is laying in wait.  */
+  iterate_over_breakpoints (pop_dummy_frame_bpt, dummy);

 
 

-void
-generic_push_dummy_frame (void)
-{
-  struct dummy_frame *dummy_frame;
-  CORE_ADDR fp = get_frame_base (get_current_frame ());
-
-  /* check to see if there are stale dummy frames, 
-     perhaps left over from when a longjump took us out of a 
-     function that was called by the debugger */
-
-  dummy_frame = dummy_frame_stack;
-  while (dummy_frame)
-    if (INNER_THAN (dummy_frame->fp, fp))      /* stale -- destroy! */
-      {
-       dummy_frame_stack = dummy_frame->next;
-       regcache_xfree (dummy_frame->regcache);
-       xfree (dummy_frame);
-       dummy_frame = dummy_frame_stack;
-      }
-    else
-      dummy_frame = dummy_frame->next;
-
-  dummy_frame = xmalloc (sizeof (struct dummy_frame));
-  dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
-
-  dummy_frame->pc = read_pc ();
-  dummy_frame->sp = read_sp ();
-  dummy_frame->top = 0;
-  dummy_frame->fp = fp;
-  dummy_frame->id = get_frame_id (get_current_frame ());
-  regcache_cpy (dummy_frame->regcache, current_regcache);
-  dummy_frame->next = dummy_frame_stack;
-  dummy_frame_stack = dummy_frame;
-}
+  /* restore_infcall_control_state frees inf_state,
+     all that remains is to pop *dummy_ptr.  */
+  *dummy_ptr = dummy->next;
+  xfree (dummy);

 
 

-void
-generic_save_dummy_frame_tos (CORE_ADDR sp)
-{
-  dummy_frame_stack->top = sp;
+  /* We've made right mess of GDB's local state, just discard
+     everything.  */
+  reinit_frame_cache ();

 }
 
 }
 

-/* Record the upper/lower bounds on the address of the call dummy.  */
+/* Look up DUMMY_ID.
+   Return NULL if not found.  */

 
 

-void
-generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
+static struct dummy_frame **
+lookup_dummy_frame (struct frame_id dummy_id)

 {
 {

-  dummy_frame_stack->call_lo = lo;
-  dummy_frame_stack->call_hi = hi;
+  struct dummy_frame **dp;
+
+  for (dp = &dummy_frame_stack; *dp != NULL; dp = &(*dp)->next)
+    {
+      if (frame_id_eq ((*dp)->id, dummy_id))
+       return dp;
+    }
+
+  return NULL;

 }
 
 }
 

-/* Restore the machine state from either the saved dummy stack or a
-   real stack frame. */
+/* Pop the dummy frame DUMMY_ID, restoring program state to that before the
+   frame was created.
+   On return reinit_frame_cache has been called.
+   If the frame isn't found, flag an internal error.
+
+   NOTE: This can only pop the one frame, even if it is in the middle of the
+   stack, because the other frames may be for different threads, and there's
+   currently no way to tell which stack frame is for which thread.  */

 
 void
 
 void

-generic_pop_current_frame (void (*popper) (struct frame_info * frame))
+dummy_frame_pop (struct frame_id dummy_id)

 {
 {

-  struct frame_info *frame = get_current_frame ();
-  if (get_frame_type (frame) == DUMMY_FRAME)
-    /* NOTE: cagney/2002-22-23: Does this ever occure?  Surely a dummy
-       frame will have already been poped by the "infrun.c" code.  */
-    generic_pop_dummy_frame ();
-  else
-    (*popper) (frame);
+  struct dummy_frame **dp;
+
+  dp = lookup_dummy_frame (dummy_id);
+  gdb_assert (dp != NULL);
+
+  pop_dummy_frame (dp);

 }
 
 }
 

-/* Function: pop_dummy_frame
-   Restore the machine state from a saved dummy stack frame. */
+/* Drop dummy frame DUMMY_ID.  Do nothing if it is not found.  Do not restore
+   its state into inferior, just free its memory.  */

 
 void
 
 void

-generic_pop_dummy_frame (void)
+dummy_frame_discard (struct frame_id dummy_id)

 {
 {

-  struct dummy_frame *dummy_frame = dummy_frame_stack;
+  struct dummy_frame **dp;

 
 

-  /* FIXME: what if the first frame isn't the right one, eg..
-     because one call-by-hand function has done a longjmp into another one? */
+  dp = lookup_dummy_frame (dummy_id);
+  if (dp)
+    remove_dummy_frame (dp);
+}

 
 

-  if (!dummy_frame)
-    error ("Can't pop dummy frame!");
-  dummy_frame_stack = dummy_frame->next;
-  regcache_cpy (current_regcache, dummy_frame->regcache);
-  flush_cached_frames ();
+/* There may be stale dummy frames, perhaps left over from when an uncaught
+   longjmp took us out of a function that was called by the debugger.  Clean
+   them up at least once whenever we start a new inferior.  */

 
 

-  regcache_xfree (dummy_frame->regcache);
-  xfree (dummy_frame);
+static void
+cleanup_dummy_frames (struct target_ops *target, int from_tty)
+{
+  while (dummy_frame_stack != NULL)
+    remove_dummy_frame (&dummy_frame_stack);

 }
 
 }
 

-/* Function: fix_call_dummy
-   Stub function.  Generic dummy frames typically do not need to fix
-   the frame being created */
+/* Return the dummy frame cache, it contains both the ID, and a
+   pointer to the regcache.  */
+struct dummy_frame_cache
+{
+  struct frame_id this_id;
+  struct regcache *prev_regcache;
+};

 
 

-void
-generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
-                       struct value **args, struct type *type, int gcc_p)
+static int
+dummy_frame_sniffer (const struct frame_unwind *self,
+                    struct frame_info *this_frame,
+                    void **this_prologue_cache)

 {
 {

-  return;
+  struct dummy_frame *dummyframe;
+  struct frame_id this_id;
+
+  /* When unwinding a normal frame, the stack structure is determined
+     by analyzing the frame's function's code (be it using brute force
+     prologue analysis, or the dwarf2 CFI).  In the case of a dummy
+     frame, that simply isn't possible.  The PC is either the program
+     entry point, or some random address on the stack.  Trying to use
+     that PC to apply standard frame ID unwind techniques is just
+     asking for trouble.  */
+  
+  /* Don't bother unless there is at least one dummy frame.  */
+  if (dummy_frame_stack != NULL)
+    {
+      /* Use an architecture specific method to extract this frame's
+        dummy ID, assuming it is a dummy frame.  */
+      this_id = gdbarch_dummy_id (get_frame_arch (this_frame), this_frame);
+
+      /* Use that ID to find the corresponding cache entry.  */
+      for (dummyframe = dummy_frame_stack;
+          dummyframe != NULL;
+          dummyframe = dummyframe->next)
+       {
+         if (frame_id_eq (dummyframe->id, this_id))
+           {
+             struct dummy_frame_cache *cache;
+
+             cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache);
+             cache->prev_regcache = get_infcall_suspend_state_regcache
+                                                  (dummyframe->caller_state);
+             cache->this_id = this_id;
+             (*this_prologue_cache) = cache;
+             return 1;
+           }
+       }
+    }
+  return 0;

 }
 
 /* Given a call-dummy dummy-frame, return the registers.  Here the
    register value is taken from the local copy of the register buffer.  */
 
 }
 
 /* Given a call-dummy dummy-frame, return the registers.  Here the
    register value is taken from the local copy of the register buffer.  */
 

-static void
-dummy_frame_register_unwind (struct frame_info *frame, void **cache,
-                            int regnum, int *optimized,
-                            enum lval_type *lvalp, CORE_ADDR *addrp,
-                            int *realnum, void *bufferp)
+static struct value *
+dummy_frame_prev_register (struct frame_info *this_frame,
+                          void **this_prologue_cache,
+                          int regnum)

 {
 {

-  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
-  gdb_assert (dummy != NULL);
+  struct dummy_frame_cache *cache = (*this_prologue_cache);
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  struct value *reg_val;
+
+  /* The dummy-frame sniffer always fills in the cache.  */
+  gdb_assert (cache != NULL);

 
   /* Describe the register's location.  Generic dummy frames always
      have the register value in an ``expression''.  */
 
   /* Describe the register's location.  Generic dummy frames always
      have the register value in an ``expression''.  */

-  *optimized = 0;
-  *lvalp = not_lval;
-  *addrp = 0;
-  *realnum = -1;
-
-  /* If needed, find and return the value of the register.  */
-  if (bufferp != NULL)
-    {
-      /* Return the actual value.  */
-      /* Use the regcache_cooked_read() method so that it, on the fly,
-         constructs either a raw or pseudo register from the raw
-         register cache.  */
-      regcache_cooked_read (dummy->regcache, regnum, bufferp);
-    }
+  reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
+
+  /* Use the regcache_cooked_read() method so that it, on the fly,
+     constructs either a raw or pseudo register from the raw
+     register cache.  */
+  regcache_cooked_read (cache->prev_regcache, regnum,
+                       value_contents_writeable (reg_val));
+  return reg_val;

 }
 
 }
 

-/* Assuming that FRAME is a dummy, return the resume address for the
-   previous frame.  */
+/* Assuming that THIS_FRAME is a dummy, return its ID.  That ID is
+   determined by examining the NEXT frame's unwound registers using
+   the method dummy_id().  As a side effect, THIS dummy frame's
+   dummy cache is located and saved in THIS_PROLOGUE_CACHE.  */

 
 

-static CORE_ADDR
-dummy_frame_pc_unwind (struct frame_info *frame,
-                      void **cache)
+static void
+dummy_frame_this_id (struct frame_info *this_frame,
+                    void **this_prologue_cache,
+                    struct frame_id *this_id)

 {
 {

-  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
-  /* Oops!  In a dummy-frame but can't find the stack dummy.  Pretend
-     that the frame doesn't unwind.  Should this function instead
-     return a has-no-caller indication?  */
-  if (dummy == NULL)
-    return 0;
-  return dummy->pc;
+  /* The dummy-frame sniffer always fills in the cache.  */
+  struct dummy_frame_cache *cache = (*this_prologue_cache);
+
+  gdb_assert (cache != NULL);
+  (*this_id) = cache->this_id;

 }
 
 }
 

+const struct frame_unwind dummy_frame_unwind =
+{
+  DUMMY_FRAME,
+  default_frame_unwind_stop_reason,
+  dummy_frame_this_id,
+  dummy_frame_prev_register,
+  NULL,
+  dummy_frame_sniffer,
+};

 
 

-/* Assuming that FRAME is a dummy, return the ID of the calling frame
-   (the frame that the dummy has the saved state of).  */
+static void
+fprint_dummy_frames (struct ui_file *file)
+{
+  struct dummy_frame *s;
+
+  for (s = dummy_frame_stack; s != NULL; s = s->next)
+    {
+      gdb_print_host_address (s, file);
+      fprintf_unfiltered (file, ":");
+      fprintf_unfiltered (file, " id=");
+      fprint_frame_id (file, s->id);
+      fprintf_unfiltered (file, "\n");
+    }
+}

 
 static void
 
 static void

-dummy_frame_id_unwind (struct frame_info *frame,
-                      void **cache,
-                      struct frame_id *id)
+maintenance_print_dummy_frames (char *args, int from_tty)

 {
 {

-  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
-  /* Oops!  In a dummy-frame but can't find the stack dummy.  Pretend
-     that the frame doesn't unwind.  Should this function instead
-     return a has-no-caller indication?  */
-  if (dummy == NULL)
-    (*id) = null_frame_id;
+  if (args == NULL)
+    fprint_dummy_frames (gdb_stdout);

   else
   else

-    (*id) = dummy->id;
+    {
+      struct cleanup *cleanups;
+      struct ui_file *file = gdb_fopen (args, "w");
+
+      if (file == NULL)
+       perror_with_name (_("maintenance print dummy-frames"));
+      cleanups = make_cleanup_ui_file_delete (file);
+      fprint_dummy_frames (file);    
+      do_cleanups (cleanups);
+    }

 }
 
 }
 

-static struct frame_unwind dummy_frame_unwind =
-{
-  dummy_frame_pc_unwind,
-  dummy_frame_id_unwind,
-  dummy_frame_register_unwind
-};
+extern void _initialize_dummy_frame (void);

 
 

-const struct frame_unwind *
-dummy_frame_p (CORE_ADDR pc)
+void
+_initialize_dummy_frame (void)

 {
 {

-  if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
-      ? DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)
-      : pc_in_dummy_frame (pc))
-    return &dummy_frame_unwind;
-  else
-    return NULL;
+  add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames,
+          _("Print the contents of the internal dummy-frame stack."),
+          &maintenanceprintlist);
+
+  observer_attach_inferior_created (cleanup_dummy_frames);

 }
 }