Initial revision

1 files changed, 650 insertions, 0 deletions

diff --git a/gdb/blockframe.c b/gdb/blockframe.c
new file mode 100644
index 0000000..7971166
--- /dev/null
+++ b/gdb/blockframe.c
@@ -0,0 +1,650 @@
+/* Get info from stack frames;
+   convert between frames, blocks, functions and pc values.
+   Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB 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 1, or (at your option)
+any later version.
+
+GDB 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 GDB; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "defs.h"
+#include "param.h"
+#include "symtab.h"
+#include "frame.h"
+#include "gdbcore.h"
+#include "value.h"		/* for read_register */
+#include "target.h"		/* for target_has_stack */
+
+/* Required by INIT_EXTRA_FRAME_INFO on 88k.  */
+#include <setjmp.h>
+#include <obstack.h>
+
+CORE_ADDR read_pc ();		/* In infcmd.c */
+
+/* Start and end of object file containing the entry point.
+   STARTUP_FILE_END is the first address of the next file.
+   This file is assumed to be a startup file
+   and frames with pc's inside it
+   are treated as nonexistent.
+
+   Setting these variables is necessary so that backtraces do not fly off
+   the bottom of the stack.  */
+CORE_ADDR startup_file_start;
+CORE_ADDR startup_file_end;
+
+/* Is ADDR outside the startup file?  Note that if your machine
+   has a way to detect the bottom of the stack, there is no need
+   to call this function from FRAME_CHAIN_VALID; the reason for
+   doing so is that some machines have no way of detecting bottom
+   of stack.  */
+int
+outside_startup_file (addr)
+     CORE_ADDR addr;
+{
+  return !(addr >= startup_file_start && addr < startup_file_end);
+}
+
+/* Address of innermost stack frame (contents of FP register) */
+
+static FRAME current_frame;
+
+/*
+ * Cache for frame addresses already read by gdb.  Valid only while
+ * inferior is stopped.  Control variables for the frame cache should
+ * be local to this module.
+ */
+struct obstack frame_cache_obstack;
+
+/* Return the innermost (currently executing) stack frame.  */
+
+FRAME
+get_current_frame ()
+{
+  /* We assume its address is kept in a general register;
+     param.h says which register.  */
+
+  return current_frame;
+}
+
+void
+set_current_frame (frame)
+     FRAME frame;
+{
+  current_frame = frame;
+}
+
+FRAME
+create_new_frame (addr, pc)
+     FRAME_ADDR addr;
+     CORE_ADDR pc;
+{
+  struct frame_info *fci;	/* Same type as FRAME */
+
+  fci = (struct frame_info *)
+    obstack_alloc (&frame_cache_obstack,
+		   sizeof (struct frame_info));
+
+  /* Arbitrary frame */
+  fci->next = (struct frame_info *) 0;
+  fci->prev = (struct frame_info *) 0;
+  fci->frame = addr;
+  fci->next_frame = 0;		/* Since arbitrary */
+  fci->pc = pc;
+
+#ifdef INIT_EXTRA_FRAME_INFO
+  INIT_EXTRA_FRAME_INFO (fci);
+#endif
+
+  return fci;
+}
+
+/* Return the frame that called FRAME.
+   If FRAME is the original frame (it has no caller), return 0.  */
+
+FRAME
+get_prev_frame (frame)
+     FRAME frame;
+{
+  /* We're allowed to know that FRAME and "struct frame_info *" are
+     the same */
+  return get_prev_frame_info (frame);
+}
+
+/* Return the frame that FRAME calls (0 if FRAME is the innermost
+   frame).  */
+
+FRAME
+get_next_frame (frame)
+     FRAME frame;
+{
+  /* We're allowed to know that FRAME and "struct frame_info *" are
+     the same */
+  return frame->next;
+}
+
+/*
+ * Flush the entire frame cache.
+ */
+void
+flush_cached_frames ()
+{
+  /* Since we can't really be sure what the first object allocated was */
+  obstack_free (&frame_cache_obstack, 0);
+  obstack_init (&frame_cache_obstack);
+
+  current_frame = (struct frame_info *) 0; /* Invalidate cache */
+}
+
+/* Return a structure containing various interesting information
+   about a specified stack frame.  */
+/* How do I justify including this function?  Well, the FRAME
+   identifier format has gone through several changes recently, and
+   it's not completely inconceivable that it could happen again.  If
+   it does, have this routine around will help */
+
+struct frame_info *
+get_frame_info (frame)
+     FRAME frame;
+{
+  return frame;
+}
+
+/* If a machine allows frameless functions, it should define a macro
+   FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h.  FI is the struct
+   frame_info for the frame, and FRAMELESS should be set to nonzero
+   if it represents a frameless function invocation.  */
+
+/* Return nonzero if the function for this frame has a prologue.  Many
+   machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
+   function.  */
+
+int
+frameless_look_for_prologue (frame)
+     FRAME frame;
+{
+  CORE_ADDR func_start, after_prologue;
+  func_start = (get_pc_function_start (frame->pc) +
+		FUNCTION_START_OFFSET);
+  if (func_start)
+    {
+      after_prologue = func_start;
+      SKIP_PROLOGUE (after_prologue);
+      return after_prologue == func_start;
+    }
+  else
+    /* If we can't find the start of the function, we don't really
+       know whether the function is frameless, but we should be able
+       to get a reasonable (i.e. best we can do under the
+       circumstances) backtrace by saying that it isn't.  */
+    return 0;
+}
+
+#if !defined (INIT_FRAME_PC)
+#define INIT_FRAME_PC(fromleaf, prev) \
+  prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
+	      prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
+#endif
+
+/* Return a structure containing various interesting information
+   about the frame that called NEXT_FRAME.  Returns NULL
+   if there is no such frame.  */
+
+struct frame_info *
+get_prev_frame_info (next_frame)
+     FRAME next_frame;
+{
+  FRAME_ADDR address;
+  struct frame_info *prev;
+  int fromleaf = 0;
+
+  /* If the requested entry is in the cache, return it.
+     Otherwise, figure out what the address should be for the entry
+     we're about to add to the cache. */
+
+  if (!next_frame)
+    {
+      if (!current_frame)
+	{
+	  error ("You haven't set up a process's stack to examine.");
+	}
+
+      return current_frame;
+    }
+
+  /* If we have the prev one, return it */
+  if (next_frame->prev)
+    return next_frame->prev;
+
+  /* On some machines it is possible to call a function without
+     setting up a stack frame for it.  On these machines, we
+     define this macro to take two args; a frameinfo pointer
+     identifying a frame and a variable to set or clear if it is
+     or isn't leafless.  */
+#ifdef FRAMELESS_FUNCTION_INVOCATION
+  /* Still don't want to worry about this except on the innermost
+     frame.  This macro will set FROMLEAF if NEXT_FRAME is a
+     frameless function invocation.  */
+  if (!(next_frame->next))
+    {
+      FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf);
+      if (fromleaf)
+	address = next_frame->frame;
+    }
+#endif
+
+  if (!fromleaf)
+    {
+      /* Two macros defined in tm.h specify the machine-dependent
+	 actions to be performed here.
+	 First, get the frame's chain-pointer.
+	 If that is zero, the frame is the outermost frame or a leaf
+	 called by the outermost frame.  This means that if start
+	 calls main without a frame, we'll return 0 (which is fine
+	 anyway).
+
+	 Nope; there's a problem.  This also returns when the current
+	 routine is a leaf of main.  This is unacceptable.  We move
+	 this to after the ffi test; I'd rather have backtraces from
+	 start go curfluy than have an abort called from main not show
+	 main.  */
+      address = FRAME_CHAIN (next_frame);
+      if (!FRAME_CHAIN_VALID (address, next_frame))
+	return 0;
+      address = FRAME_CHAIN_COMBINE (address, next_frame);
+    }
+
+  prev = (struct frame_info *)
+    obstack_alloc (&frame_cache_obstack,
+		   sizeof (struct frame_info));
+
+  if (next_frame)
+    next_frame->prev = prev;
+  prev->next = next_frame;
+  prev->prev = (struct frame_info *) 0;
+  prev->frame = address;
+  prev->next_frame = prev->next ? prev->next->frame : 0;
+
+#ifdef INIT_EXTRA_FRAME_INFO
+  INIT_EXTRA_FRAME_INFO(prev);
+#endif
+
+  /* This entry is in the frame queue now, which is good since
+     FRAME_SAVED_PC may use that queue to figure out it's value
+     (see m-sparc.h).  We want the pc saved in the inferior frame. */
+  INIT_FRAME_PC(fromleaf, prev);
+
+  return prev;
+}
+
+CORE_ADDR
+get_frame_pc (frame)
+     FRAME frame;
+{
+  struct frame_info *fi;
+  fi = get_frame_info (frame);
+  return fi->pc;
+}
+
+#if defined (FRAME_FIND_SAVED_REGS)
+/* Find the addresses in which registers are saved in FRAME.  */
+
+void
+get_frame_saved_regs (frame_info_addr, saved_regs_addr)
+     struct frame_info *frame_info_addr;
+     struct frame_saved_regs *saved_regs_addr;
+{
+  FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr);
+}
+#endif
+
+/* Return the innermost lexical block in execution
+   in a specified stack frame.  The frame address is assumed valid.  */
+
+struct block *
+get_frame_block (frame)
+     FRAME frame;
+{
+  struct frame_info *fi;
+  CORE_ADDR pc;
+
+  fi = get_frame_info (frame);
+
+  pc = fi->pc;
+  if (fi->next_frame != 0)
+    /* We are not in the innermost frame.  We need to subtract one to
+       get the correct block, in case the call instruction was the
+       last instruction of the block.  If there are any machines on
+       which the saved pc does not point to after the call insn, we
+       probably want to make fi->pc point after the call insn anyway.  */
+    --pc;
+  return block_for_pc (pc);
+}
+
+struct block *
+get_current_block ()
+{
+  return block_for_pc (read_pc ());
+}
+
+CORE_ADDR
+get_pc_function_start (pc)
+     CORE_ADDR pc;
+{
+  register struct block *bl = block_for_pc (pc);
+  register struct symbol *symbol;
+  if (bl == 0 || (symbol = block_function (bl)) == 0)
+    {
+      register int misc_index = find_pc_misc_function (pc);
+      if (misc_index >= 0)
+	return misc_function_vector[misc_index].address;
+      return 0;
+    }
+  bl = SYMBOL_BLOCK_VALUE (symbol);
+  return BLOCK_START (bl);
+}
+
+/* Return the symbol for the function executing in frame FRAME.  */
+
+struct symbol *
+get_frame_function (frame)
+     FRAME frame;
+{
+  register struct block *bl = get_frame_block (frame);
+  if (bl == 0)
+    return 0;
+  return block_function (bl);
+}
+
+/* Return the blockvector immediately containing the innermost lexical block
+   containing the specified pc value, or 0 if there is none.
+   PINDEX is a pointer to the index value of the block.  If PINDEX
+   is NULL, we don't pass this information back to the caller.  */
+
+struct blockvector *
+blockvector_for_pc (pc, pindex)
+     register CORE_ADDR pc;
+     int *pindex;
+{
+  register struct block *b;
+  register int bot, top, half;
+  register struct symtab *s;
+  struct blockvector *bl;
+
+  /* First search all symtabs for one whose file contains our pc */
+  s = find_pc_symtab (pc);
+  if (s == 0)
+    return 0;
+
+  bl = BLOCKVECTOR (s);
+  b = BLOCKVECTOR_BLOCK (bl, 0);
+
+  /* Then search that symtab for the smallest block that wins.  */
+  /* Use binary search to find the last block that starts before PC.  */
+
+  bot = 0;
+  top = BLOCKVECTOR_NBLOCKS (bl);
+
+  while (top - bot > 1)
+    {
+      half = (top - bot + 1) >> 1;
+      b = BLOCKVECTOR_BLOCK (bl, bot + half);
+      if (BLOCK_START (b) <= pc)
+	bot += half;
+      else
+	top = bot + half;
+    }
+
+  /* Now search backward for a block that ends after PC.  */
+
+  while (bot >= 0)
+    {
+      b = BLOCKVECTOR_BLOCK (bl, bot);
+      if (BLOCK_END (b) > pc)
+	{
+	  if (pindex)
+	    *pindex = bot;
+	  return bl;
+	}
+      bot--;
+    }
+
+  return 0;
+}
+
+/* Return the innermost lexical block containing the specified pc value,
+   or 0 if there is none.  */
+
+struct block *
+block_for_pc (pc)
+     register CORE_ADDR pc;
+{
+  register struct blockvector *bl;
+  int index;
+
+  bl = blockvector_for_pc (pc, &index);
+  if (bl)
+    return BLOCKVECTOR_BLOCK (bl, index);
+  return 0;
+}
+
+/* Return the function containing pc value PC.
+   Returns 0 if function is not known.  */
+
+struct symbol *
+find_pc_function (pc)
+     CORE_ADDR pc;
+{
+  register struct block *b = block_for_pc (pc);
+  if (b == 0)
+    return 0;
+  return block_function (b);
+}
+
+/* These variables are used to cache the most recent result
+ * of find_pc_partial_function. */
+
+static CORE_ADDR cache_pc_function_low = 0;
+static CORE_ADDR cache_pc_function_high = 0;
+static char *cache_pc_function_name = 0;
+
+/* Clear cache, e.g. when symbol table is discarded. */
+
+void
+clear_pc_function_cache()
+{
+  cache_pc_function_low = 0;
+  cache_pc_function_high = 0;
+  cache_pc_function_name = (char *)0;
+}
+
+/* Finds the "function" (text symbol) that is smaller than PC
+   but greatest of all of the potential text symbols.  Sets
+   *NAME and/or *ADDRESS conditionally if that pointer is non-zero.
+   Returns 0 if it couldn't find anything, 1 if it did.  On a zero
+   return, *NAME and *ADDRESS are always set to zero.  On a 1 return,
+   *NAME and *ADDRESS contain real information.  */
+
+int
+find_pc_partial_function (pc, name, address)
+     CORE_ADDR pc;
+     char **name;
+     CORE_ADDR *address;
+{
+  struct partial_symtab *pst;
+  struct symbol *f;
+  int miscfunc;
+  struct partial_symbol *psb;
+
+  if (pc >= cache_pc_function_low && pc < cache_pc_function_high)
+    {
+	if (address)
+	    *address = cache_pc_function_low;
+	if (name)
+	    *name = cache_pc_function_name;
+	return 1;
+    }
+
+  pst = find_pc_psymtab (pc);
+  if (pst)
+    {
+      if (pst->readin)
+	{
+	  /* The information we want has already been read in.
+	     We can go to the already readin symbols and we'll get
+	     the best possible answer.  */
+	  f = find_pc_function (pc);
+	  if (!f)
+	    {
+	    return_error:
+	      /* No available symbol.  */
+	      if (name != 0)
+		*name = 0;
+	      if (address != 0)
+		*address = 0;
+	      return 0;
+	    }
+
+	  cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
+	  cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
+	  cache_pc_function_name = SYMBOL_NAME (f);
+	  if (name)
+	    *name = cache_pc_function_name;
+	  if (address)
+	    *address = cache_pc_function_low;
+	  return 1;
+	}
+
+      /* Get the information from a combination of the pst
+	 (static symbols), and the misc function vector (extern
+	 symbols).  */
+      miscfunc = find_pc_misc_function (pc);
+      psb = find_pc_psymbol (pst, pc);
+
+      if (!psb && miscfunc == -1)
+	{
+	  goto return_error;
+	}
+      if (psb
+	  && (miscfunc == -1
+	      || (SYMBOL_VALUE_ADDRESS (psb)
+		  >= misc_function_vector[miscfunc].address)))
+	{
+	  /* This case isn't being cached currently. */
+	  if (address)
+	    *address = SYMBOL_VALUE_ADDRESS (psb);
+	  if (name)
+	    *name = SYMBOL_NAME (psb);
+	  return 1;
+	}
+    }
+  else
+    /* Must be in the misc function stuff.  */
+    {
+      miscfunc = find_pc_misc_function (pc);
+      if (miscfunc == -1)
+	goto return_error;
+    }
+
+  {
+    if (misc_function_vector[miscfunc].type == mf_text)
+      cache_pc_function_low = misc_function_vector[miscfunc].address;
+    else
+      /* It is a transfer table for Sun shared libraries.  */
+      cache_pc_function_low = pc - FUNCTION_START_OFFSET;
+  }
+  cache_pc_function_name = misc_function_vector[miscfunc].name;
+  if (miscfunc < misc_function_count && 1 /* FIXME mf_text again? */ )
+    cache_pc_function_high = misc_function_vector[miscfunc+1].address;
+  else
+    cache_pc_function_high = cache_pc_function_low + 1;
+  if (address)
+    *address = cache_pc_function_low;
+  if (name)
+    *name = cache_pc_function_name;
+  return 1;
+}
+
+/* Find the misc function whose address is the largest
+   while being less than PC.  Return its index in misc_function_vector.
+   Returns -1 if PC is not in suitable range.  */
+
+int
+find_pc_misc_function (pc)
+     register CORE_ADDR pc;
+{
+  register int lo = 0;
+  register int hi = misc_function_count-1;
+  register int new;
+
+  /* Note that the last thing in the vector is always _etext.  */
+  /* Actually, "end", now that non-functions
+     go on the misc_function_vector.  */
+
+  /* Above statement is not *always* true - fix for case where there are */
+  /* no misc functions at all (ie no symbol table has been read). */
+  if (hi < 0) return -1;        /* no misc functions recorded */
+
+  /* trivial reject range test */
+  if (pc < misc_function_vector[0].address ||
+      pc > misc_function_vector[hi].address)
+    return -1;
+
+  /* Note that the following search will not return hi if
+     pc == misc_function_vector[hi].address.  If "end" points to the
+     first unused location, this is correct and the above test
+     simply needs to be changed to
+     "pc >= misc_function_vector[hi].address".  */
+  do {
+    new = (lo + hi) >> 1;
+    if (misc_function_vector[new].address == pc)
+      return new;		/* an exact match */
+    else if (misc_function_vector[new].address > pc)
+      hi = new;
+    else
+      lo = new;
+  } while (hi-lo != 1);
+
+  /* if here, we had no exact match, so return the lower choice */
+  return lo;
+}
+
+/* Return the innermost stack frame executing inside of the specified block,
+   or zero if there is no such frame.  */
+
+FRAME
+block_innermost_frame (block)
+     struct block *block;
+{
+  struct frame_info *fi;
+  register FRAME frame;
+  register CORE_ADDR start = BLOCK_START (block);
+  register CORE_ADDR end = BLOCK_END (block);
+
+  frame = 0;
+  while (1)
+    {
+      frame = get_prev_frame (frame);
+      if (frame == 0)
+	return 0;
+      fi = get_frame_info (frame);
+      if (fi->pc >= start && fi->pc < end)
+	return frame;
+    }
+}
+
+void
+_initialize_blockframe ()
+{
+  obstack_init (&frame_cache_obstack);
+}