Initial revision

1 files changed, 1130 insertions, 0 deletions

diff --git a/gdb/buildsym.c b/gdb/buildsym.c
new file mode 100644
index 00000000000..24b64bead2e
--- /dev/null
+++ b/gdb/buildsym.c
@@ -0,0 +1,1130 @@
+/* Support routines for building symbol tables in GDB's internal format.
+   Copyright 1986-1999 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
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* This module provides subroutines used for creating and adding to
+   the symbol table.  These routines are called from various symbol-
+   file-reading routines.
+
+   Routines to support specific debugging information formats (stabs,
+   DWARF, etc) belong somewhere else. */
+
+#include "defs.h"
+#include "bfd.h"
+#include "obstack.h"
+#include "symtab.h"
+#include "symfile.h"		/* Needed for "struct complaint" */
+#include "objfiles.h"
+#include "gdbtypes.h"
+#include "complaints.h"
+#include "gdb_string.h"
+
+/* Ask buildsym.h to define the vars it normally declares `extern'.  */
+#define	EXTERN			/**/
+#include "buildsym.h"		/* Our own declarations */
+#undef	EXTERN
+
+/* For cleanup_undefined_types and finish_global_stabs (somewhat
+   questionable--see comment where we call them).  */
+
+#include "stabsread.h"
+
+/* List of free `struct pending' structures for reuse.  */
+
+static struct pending *free_pendings;
+
+/* Non-zero if symtab has line number info.  This prevents an
+   otherwise empty symtab from being tossed.  */
+
+static int have_line_numbers;
+
+static int compare_line_numbers (const void *ln1p, const void *ln2p);
+
+
+/* Initial sizes of data structures.  These are realloc'd larger if
+   needed, and realloc'd down to the size actually used, when
+   completed.  */
+
+#define	INITIAL_CONTEXT_STACK_SIZE	10
+#define	INITIAL_LINE_VECTOR_LENGTH	1000
+
+
+/* Complaints about the symbols we have encountered.  */
+
+struct complaint block_end_complaint =
+{"block end address less than block start address in %s (patched it)", 0, 0};
+
+struct complaint anon_block_end_complaint =
+{"block end address 0x%lx less than block start address 0x%lx (patched it)", 0, 0};
+
+struct complaint innerblock_complaint =
+{"inner block not inside outer block in %s", 0, 0};
+
+struct complaint innerblock_anon_complaint =
+{"inner block (0x%lx-0x%lx) not inside outer block (0x%lx-0x%lx)", 0, 0};
+
+struct complaint blockvector_complaint =
+{"block at 0x%lx out of order", 0, 0};
+
+/* maintain the lists of symbols and blocks */
+
+/* Add a symbol to one of the lists of symbols.  */
+
+void
+add_symbol_to_list (struct symbol *symbol, struct pending **listhead)
+{
+  register struct pending *link;
+
+  /* If this is an alias for another symbol, don't add it.  */
+  if (symbol->ginfo.name && symbol->ginfo.name[0] == '#')
+    return;
+
+  /* We keep PENDINGSIZE symbols in each link of the list. If we
+     don't have a link with room in it, add a new link.  */
+  if (*listhead == NULL || (*listhead)->nsyms == PENDINGSIZE)
+    {
+      if (free_pendings)
+	{
+	  link = free_pendings;
+	  free_pendings = link->next;
+	}
+      else
+	{
+	  link = (struct pending *) xmalloc (sizeof (struct pending));
+	}
+
+      link->next = *listhead;
+      *listhead = link;
+      link->nsyms = 0;
+    }
+
+  (*listhead)->symbol[(*listhead)->nsyms++] = symbol;
+}
+
+/* Find a symbol named NAME on a LIST.  NAME need not be
+   '\0'-terminated; LENGTH is the length of the name.  */
+
+struct symbol *
+find_symbol_in_list (struct pending *list, char *name, int length)
+{
+  int j;
+  char *pp;
+
+  while (list != NULL)
+    {
+      for (j = list->nsyms; --j >= 0;)
+	{
+	  pp = SYMBOL_NAME (list->symbol[j]);
+	  if (*pp == *name && strncmp (pp, name, length) == 0 &&
+	      pp[length] == '\0')
+	    {
+	      return (list->symbol[j]);
+	    }
+	}
+      list = list->next;
+    }
+  return (NULL);
+}
+
+/* At end of reading syms, or in case of quit, really free as many
+   `struct pending's as we can easily find. */
+
+/* ARGSUSED */
+void
+really_free_pendings (int foo)
+{
+  struct pending *next, *next1;
+
+  for (next = free_pendings; next; next = next1)
+    {
+      next1 = next->next;
+      free ((void *) next);
+    }
+  free_pendings = NULL;
+
+  free_pending_blocks ();
+
+  for (next = file_symbols; next != NULL; next = next1)
+    {
+      next1 = next->next;
+      free ((void *) next);
+    }
+  file_symbols = NULL;
+
+  for (next = global_symbols; next != NULL; next = next1)
+    {
+      next1 = next->next;
+      free ((void *) next);
+    }
+  global_symbols = NULL;
+}
+
+/* This function is called to discard any pending blocks. */
+
+void
+free_pending_blocks (void)
+{
+#if 0				/* Now we make the links in the
+				   symbol_obstack, so don't free
+				   them.  */
+  struct pending_block *bnext, *bnext1;
+
+  for (bnext = pending_blocks; bnext; bnext = bnext1)
+    {
+      bnext1 = bnext->next;
+      free ((void *) bnext);
+    }
+#endif
+  pending_blocks = NULL;
+}
+
+/* Take one of the lists of symbols and make a block from it.  Keep
+   the order the symbols have in the list (reversed from the input
+   file).  Put the block on the list of pending blocks.  */
+
+void
+finish_block (struct symbol *symbol, struct pending **listhead,
+	      struct pending_block *old_blocks,
+	      CORE_ADDR start, CORE_ADDR end,
+	      struct objfile *objfile)
+{
+  register struct pending *next, *next1;
+  register struct block *block;
+  register struct pending_block *pblock;
+  struct pending_block *opblock;
+  register int i;
+  register int j;
+
+  /* Count the length of the list of symbols.  */
+
+  for (next = *listhead, i = 0;
+       next;
+       i += next->nsyms, next = next->next)
+    {
+      /* EMPTY */ ;
+    }
+
+  block = (struct block *) obstack_alloc (&objfile->symbol_obstack,
+    (sizeof (struct block) + ((i - 1) * sizeof (struct symbol *))));
+
+  /* Copy the symbols into the block.  */
+
+  BLOCK_NSYMS (block) = i;
+  for (next = *listhead; next; next = next->next)
+    {
+      for (j = next->nsyms - 1; j >= 0; j--)
+	{
+	  BLOCK_SYM (block, --i) = next->symbol[j];
+	}
+    }
+
+  BLOCK_START (block) = start;
+  BLOCK_END (block) = end;
+  /* Superblock filled in when containing block is made */
+  BLOCK_SUPERBLOCK (block) = NULL;
+
+  BLOCK_GCC_COMPILED (block) = processing_gcc_compilation;
+
+  /* Put the block in as the value of the symbol that names it.  */
+
+  if (symbol)
+    {
+      struct type *ftype = SYMBOL_TYPE (symbol);
+      SYMBOL_BLOCK_VALUE (symbol) = block;
+      BLOCK_FUNCTION (block) = symbol;
+
+      if (TYPE_NFIELDS (ftype) <= 0)
+	{
+	  /* No parameter type information is recorded with the
+	     function's type.  Set that from the type of the
+	     parameter symbols. */
+	  int nparams = 0, iparams;
+	  struct symbol *sym;
+	  for (i = 0; i < BLOCK_NSYMS (block); i++)
+	    {
+	      sym = BLOCK_SYM (block, i);
+	      switch (SYMBOL_CLASS (sym))
+		{
+		case LOC_ARG:
+		case LOC_REF_ARG:
+		case LOC_REGPARM:
+		case LOC_REGPARM_ADDR:
+		case LOC_BASEREG_ARG:
+		case LOC_LOCAL_ARG:
+		  nparams++;
+		  break;
+		case LOC_UNDEF:
+		case LOC_CONST:
+		case LOC_STATIC:
+		case LOC_INDIRECT:
+		case LOC_REGISTER:
+		case LOC_LOCAL:
+		case LOC_TYPEDEF:
+		case LOC_LABEL:
+		case LOC_BLOCK:
+		case LOC_CONST_BYTES:
+		case LOC_BASEREG:
+		case LOC_UNRESOLVED:
+		case LOC_OPTIMIZED_OUT:
+		default:
+		  break;
+		}
+	    }
+	  if (nparams > 0)
+	    {
+	      TYPE_NFIELDS (ftype) = nparams;
+	      TYPE_FIELDS (ftype) = (struct field *)
+		TYPE_ALLOC (ftype, nparams * sizeof (struct field));
+
+	      for (i = iparams = 0; iparams < nparams; i++)
+		{
+		  sym = BLOCK_SYM (block, i);
+		  switch (SYMBOL_CLASS (sym))
+		    {
+		    case LOC_ARG:
+		    case LOC_REF_ARG:
+		    case LOC_REGPARM:
+		    case LOC_REGPARM_ADDR:
+		    case LOC_BASEREG_ARG:
+		    case LOC_LOCAL_ARG:
+		      TYPE_FIELD_TYPE (ftype, iparams) = SYMBOL_TYPE (sym);
+		      iparams++;
+		      break;
+		    case LOC_UNDEF:
+		    case LOC_CONST:
+		    case LOC_STATIC:
+		    case LOC_INDIRECT:
+		    case LOC_REGISTER:
+		    case LOC_LOCAL:
+		    case LOC_TYPEDEF:
+		    case LOC_LABEL:
+		    case LOC_BLOCK:
+		    case LOC_CONST_BYTES:
+		    case LOC_BASEREG:
+		    case LOC_UNRESOLVED:
+		    case LOC_OPTIMIZED_OUT:
+		    default:
+		      break;
+		    }
+		}
+	    }
+	}
+    }
+  else
+    {
+      BLOCK_FUNCTION (block) = NULL;
+    }
+
+  /* Now "free" the links of the list, and empty the list.  */
+
+  for (next = *listhead; next; next = next1)
+    {
+      next1 = next->next;
+      next->next = free_pendings;
+      free_pendings = next;
+    }
+  *listhead = NULL;
+
+#if 1
+  /* Check to be sure that the blocks have an end address that is
+     greater than starting address */
+
+  if (BLOCK_END (block) < BLOCK_START (block))
+    {
+      if (symbol)
+	{
+	  complain (&block_end_complaint, SYMBOL_SOURCE_NAME (symbol));
+	}
+      else
+	{
+	  complain (&anon_block_end_complaint, BLOCK_END (block), BLOCK_START (block));
+	}
+      /* Better than nothing */
+      BLOCK_END (block) = BLOCK_START (block);
+    }
+#endif
+
+  /* Install this block as the superblock of all blocks made since the
+     start of this scope that don't have superblocks yet.  */
+
+  opblock = NULL;
+  for (pblock = pending_blocks; pblock != old_blocks; pblock = pblock->next)
+    {
+      if (BLOCK_SUPERBLOCK (pblock->block) == NULL)
+	{
+#if 1
+	  /* Check to be sure the blocks are nested as we receive
+	     them. If the compiler/assembler/linker work, this just
+	     burns a small amount of time.  */
+	  if (BLOCK_START (pblock->block) < BLOCK_START (block) ||
+	      BLOCK_END (pblock->block) > BLOCK_END (block))
+	    {
+	      if (symbol)
+		{
+		  complain (&innerblock_complaint,
+			    SYMBOL_SOURCE_NAME (symbol));
+		}
+	      else
+		{
+		  complain (&innerblock_anon_complaint, BLOCK_START (pblock->block),
+		     BLOCK_END (pblock->block), BLOCK_START (block),
+			    BLOCK_END (block));
+		}
+	      if (BLOCK_START (pblock->block) < BLOCK_START (block))
+		BLOCK_START (pblock->block) = BLOCK_START (block);
+	      if (BLOCK_END (pblock->block) > BLOCK_END (block))
+		BLOCK_END (pblock->block) = BLOCK_END (block);
+	    }
+#endif
+	  BLOCK_SUPERBLOCK (pblock->block) = block;
+	}
+      opblock = pblock;
+    }
+
+  record_pending_block (objfile, block, opblock);
+}
+
+/* Record BLOCK on the list of all blocks in the file.  Put it after
+   OPBLOCK, or at the beginning if opblock is NULL.  This puts the
+   block in the list after all its subblocks.
+
+   Allocate the pending block struct in the symbol_obstack to save
+   time.  This wastes a little space.  FIXME: Is it worth it?  */
+
+void
+record_pending_block (struct objfile *objfile, struct block *block,
+		      struct pending_block *opblock)
+{
+  register struct pending_block *pblock;
+
+  pblock = (struct pending_block *)
+    obstack_alloc (&objfile->symbol_obstack, sizeof (struct pending_block));
+  pblock->block = block;
+  if (opblock)
+    {
+      pblock->next = opblock->next;
+      opblock->next = pblock;
+    }
+  else
+    {
+      pblock->next = pending_blocks;
+      pending_blocks = pblock;
+    }
+}
+
+/* Note that this is only used in this file and in dstread.c, which
+   should be fixed to not need direct access to this function.  When
+   that is done, it can be made static again. */
+
+struct blockvector *
+make_blockvector (struct objfile *objfile)
+{
+  register struct pending_block *next;
+  register struct blockvector *blockvector;
+  register int i;
+
+  /* Count the length of the list of blocks.  */
+
+  for (next = pending_blocks, i = 0; next; next = next->next, i++)
+    {;
+    }
+
+  blockvector = (struct blockvector *)
+    obstack_alloc (&objfile->symbol_obstack,
+		   (sizeof (struct blockvector)
+		    + (i - 1) * sizeof (struct block *)));
+
+  /* Copy the blocks into the blockvector. This is done in reverse
+     order, which happens to put the blocks into the proper order
+     (ascending starting address). finish_block has hair to insert
+     each block into the list after its subblocks in order to make
+     sure this is true.  */
+
+  BLOCKVECTOR_NBLOCKS (blockvector) = i;
+  for (next = pending_blocks; next; next = next->next)
+    {
+      BLOCKVECTOR_BLOCK (blockvector, --i) = next->block;
+    }
+
+#if 0				/* Now we make the links in the
+				   obstack, so don't free them.  */
+  /* Now free the links of the list, and empty the list.  */
+
+  for (next = pending_blocks; next; next = next1)
+    {
+      next1 = next->next;
+      free (next);
+    }
+#endif
+  pending_blocks = NULL;
+
+#if 1				/* FIXME, shut this off after a while
+				   to speed up symbol reading.  */
+  /* Some compilers output blocks in the wrong order, but we depend on
+     their being in the right order so we can binary search. Check the
+     order and moan about it.  FIXME.  */
+  if (BLOCKVECTOR_NBLOCKS (blockvector) > 1)
+    {
+      for (i = 1; i < BLOCKVECTOR_NBLOCKS (blockvector); i++)
+	{
+	  if (BLOCK_START (BLOCKVECTOR_BLOCK (blockvector, i - 1))
+	      > BLOCK_START (BLOCKVECTOR_BLOCK (blockvector, i)))
+	    {
+
+	      /* FIXME-32x64: loses if CORE_ADDR doesn't fit in a
+	         long.  Possible solutions include a version of
+	         complain which takes a callback, a
+	         sprintf_address_numeric to match
+	         print_address_numeric, or a way to set up a GDB_FILE
+	         which causes sprintf rather than fprintf to be
+	         called.  */
+
+	      complain (&blockvector_complaint,
+			(unsigned long) BLOCK_START (BLOCKVECTOR_BLOCK (blockvector, i)));
+	    }
+	}
+    }
+#endif
+
+  return (blockvector);
+}
+
+/* Start recording information about source code that came from an
+   included (or otherwise merged-in) source file with a different
+   name.  NAME is the name of the file (cannot be NULL), DIRNAME is
+   the directory in which it resides (or NULL if not known).  */
+
+void
+start_subfile (char *name, char *dirname)
+{
+  register struct subfile *subfile;
+
+  /* See if this subfile is already known as a subfile of the current
+     main source file.  */
+
+  for (subfile = subfiles; subfile; subfile = subfile->next)
+    {
+      if (STREQ (subfile->name, name))
+	{
+	  current_subfile = subfile;
+	  return;
+	}
+    }
+
+  /* This subfile is not known.  Add an entry for it. Make an entry
+     for this subfile in the list of all subfiles of the current main
+     source file.  */
+
+  subfile = (struct subfile *) xmalloc (sizeof (struct subfile));
+  subfile->next = subfiles;
+  subfiles = subfile;
+  current_subfile = subfile;
+
+  /* Save its name and compilation directory name */
+  subfile->name = (name == NULL) ? NULL : savestring (name, strlen (name));
+  subfile->dirname =
+    (dirname == NULL) ? NULL : savestring (dirname, strlen (dirname));
+
+  /* Initialize line-number recording for this subfile.  */
+  subfile->line_vector = NULL;
+
+  /* Default the source language to whatever can be deduced from the
+     filename.  If nothing can be deduced (such as for a C/C++ include
+     file with a ".h" extension), then inherit whatever language the
+     previous subfile had.  This kludgery is necessary because there
+     is no standard way in some object formats to record the source
+     language.  Also, when symtabs are allocated we try to deduce a
+     language then as well, but it is too late for us to use that
+     information while reading symbols, since symtabs aren't allocated
+     until after all the symbols have been processed for a given
+     source file. */
+
+  subfile->language = deduce_language_from_filename (subfile->name);
+  if (subfile->language == language_unknown &&
+      subfile->next != NULL)
+    {
+      subfile->language = subfile->next->language;
+    }
+
+  /* Initialize the debug format string to NULL.  We may supply it
+     later via a call to record_debugformat. */
+  subfile->debugformat = NULL;
+
+  /* cfront output is a C program, so in most ways it looks like a C
+     program.  But to demangle we need to set the language to C++.  We
+     can distinguish cfront code by the fact that it has #line
+     directives which specify a file name ending in .C.
+  
+     So if the filename of this subfile ends in .C, then change the
+     language of any pending subfiles from C to C++.  We also accept
+     any other C++ suffixes accepted by deduce_language_from_filename
+     (in particular, some people use .cxx with cfront).  */
+  /* Likewise for f2c.  */
+
+  if (subfile->name)
+    {
+      struct subfile *s;
+      enum language sublang = deduce_language_from_filename (subfile->name);
+
+      if (sublang == language_cplus || sublang == language_fortran)
+	for (s = subfiles; s != NULL; s = s->next)
+	  if (s->language == language_c)
+	    s->language = sublang;
+    }
+
+  /* And patch up this file if necessary.  */
+  if (subfile->language == language_c
+      && subfile->next != NULL
+      && (subfile->next->language == language_cplus
+	  || subfile->next->language == language_fortran))
+    {
+      subfile->language = subfile->next->language;
+    }
+}
+
+/* For stabs readers, the first N_SO symbol is assumed to be the
+   source file name, and the subfile struct is initialized using that
+   assumption.  If another N_SO symbol is later seen, immediately
+   following the first one, then the first one is assumed to be the
+   directory name and the second one is really the source file name.
+
+   So we have to patch up the subfile struct by moving the old name
+   value to dirname and remembering the new name.  Some sanity
+   checking is performed to ensure that the state of the subfile
+   struct is reasonable and that the old name we are assuming to be a
+   directory name actually is (by checking for a trailing '/'). */
+
+void
+patch_subfile_names (struct subfile *subfile, char *name)
+{
+  if (subfile != NULL && subfile->dirname == NULL && subfile->name != NULL
+      && subfile->name[strlen (subfile->name) - 1] == '/')
+    {
+      subfile->dirname = subfile->name;
+      subfile->name = savestring (name, strlen (name));
+      last_source_file = name;
+
+      /* Default the source language to whatever can be deduced from
+         the filename.  If nothing can be deduced (such as for a C/C++
+         include file with a ".h" extension), then inherit whatever
+         language the previous subfile had.  This kludgery is
+         necessary because there is no standard way in some object
+         formats to record the source language.  Also, when symtabs
+         are allocated we try to deduce a language then as well, but
+         it is too late for us to use that information while reading
+         symbols, since symtabs aren't allocated until after all the
+         symbols have been processed for a given source file. */
+
+      subfile->language = deduce_language_from_filename (subfile->name);
+      if (subfile->language == language_unknown &&
+	  subfile->next != NULL)
+	{
+	  subfile->language = subfile->next->language;
+	}
+    }
+}
+
+/* Handle the N_BINCL and N_EINCL symbol types that act like N_SOL for
+   switching source files (different subfiles, as we call them) within
+   one object file, but using a stack rather than in an arbitrary
+   order.  */
+
+void
+push_subfile (void)
+{
+  register struct subfile_stack *tem
+  = (struct subfile_stack *) xmalloc (sizeof (struct subfile_stack));
+
+  tem->next = subfile_stack;
+  subfile_stack = tem;
+  if (current_subfile == NULL || current_subfile->name == NULL)
+    {
+      abort ();
+    }
+  tem->name = current_subfile->name;
+}
+
+char *
+pop_subfile (void)
+{
+  register char *name;
+  register struct subfile_stack *link = subfile_stack;
+
+  if (link == NULL)
+    {
+      abort ();
+    }
+  name = link->name;
+  subfile_stack = link->next;
+  free ((void *) link);
+  return (name);
+}
+
+/* Add a linetable entry for line number LINE and address PC to the
+   line vector for SUBFILE.  */
+
+void
+record_line (register struct subfile *subfile, int line, CORE_ADDR pc)
+{
+  struct linetable_entry *e;
+  /* Ignore the dummy line number in libg.o */
+
+  if (line == 0xffff)
+    {
+      return;
+    }
+
+  /* Make sure line vector exists and is big enough.  */
+  if (!subfile->line_vector)
+    {
+      subfile->line_vector_length = INITIAL_LINE_VECTOR_LENGTH;
+      subfile->line_vector = (struct linetable *)
+	xmalloc (sizeof (struct linetable)
+		 + subfile->line_vector_length * sizeof (struct linetable_entry));
+      subfile->line_vector->nitems = 0;
+      have_line_numbers = 1;
+    }
+
+  if (subfile->line_vector->nitems + 1 >= subfile->line_vector_length)
+    {
+      subfile->line_vector_length *= 2;
+      subfile->line_vector = (struct linetable *)
+	xrealloc ((char *) subfile->line_vector,
+		  (sizeof (struct linetable)
+		   + (subfile->line_vector_length
+		      * sizeof (struct linetable_entry))));
+    }
+
+  e = subfile->line_vector->item + subfile->line_vector->nitems++;
+  e->line = line;
+  e->pc = pc;
+}
+
+/* Needed in order to sort line tables from IBM xcoff files.  Sigh!  */
+
+static int
+compare_line_numbers (const void *ln1p, const void *ln2p)
+{
+  struct linetable_entry *ln1 = (struct linetable_entry *) ln1p;
+  struct linetable_entry *ln2 = (struct linetable_entry *) ln2p;
+
+  /* Note: this code does not assume that CORE_ADDRs can fit in ints.
+     Please keep it that way.  */
+  if (ln1->pc < ln2->pc)
+    return -1;
+
+  if (ln1->pc > ln2->pc)
+    return 1;
+
+  /* If pc equal, sort by line.  I'm not sure whether this is optimum
+     behavior (see comment at struct linetable in symtab.h).  */
+  return ln1->line - ln2->line;
+}
+
+/* Start a new symtab for a new source file.  Called, for example,
+   when a stabs symbol of type N_SO is seen, or when a DWARF
+   TAG_compile_unit DIE is seen.  It indicates the start of data for
+   one original source file.  */
+
+void
+start_symtab (char *name, char *dirname, CORE_ADDR start_addr)
+{
+
+  last_source_file = name;
+  last_source_start_addr = start_addr;
+  file_symbols = NULL;
+  global_symbols = NULL;
+  within_function = 0;
+  have_line_numbers = 0;
+
+  /* Context stack is initially empty.  Allocate first one with room
+     for 10 levels; reuse it forever afterward.  */
+  if (context_stack == NULL)
+    {
+      context_stack_size = INITIAL_CONTEXT_STACK_SIZE;
+      context_stack = (struct context_stack *)
+	xmalloc (context_stack_size * sizeof (struct context_stack));
+    }
+  context_stack_depth = 0;
+
+  /* Initialize the list of sub source files with one entry for this
+     file (the top-level source file).  */
+
+  subfiles = NULL;
+  current_subfile = NULL;
+  start_subfile (name, dirname);
+}
+
+/* Finish the symbol definitions for one main source file, close off
+   all the lexical contexts for that file (creating struct block's for
+   them), then make the struct symtab for that file and put it in the
+   list of all such.
+
+   END_ADDR is the address of the end of the file's text.  SECTION is
+   the section number (in objfile->section_offsets) of the blockvector
+   and linetable.
+
+   Note that it is possible for end_symtab() to return NULL.  In
+   particular, for the DWARF case at least, it will return NULL when
+   it finds a compilation unit that has exactly one DIE, a
+   TAG_compile_unit DIE.  This can happen when we link in an object
+   file that was compiled from an empty source file.  Returning NULL
+   is probably not the correct thing to do, because then gdb will
+   never know about this empty file (FIXME). */
+
+struct symtab *
+end_symtab (CORE_ADDR end_addr, struct objfile *objfile, int section)
+{
+  register struct symtab *symtab = NULL;
+  register struct blockvector *blockvector;
+  register struct subfile *subfile;
+  register struct context_stack *cstk;
+  struct subfile *nextsub;
+
+  /* Finish the lexical context of the last function in the file; pop
+     the context stack.  */
+
+  if (context_stack_depth > 0)
+    {
+      cstk = pop_context ();
+      /* Make a block for the local symbols within.  */
+      finish_block (cstk->name, &local_symbols, cstk->old_blocks,
+		    cstk->start_addr, end_addr, objfile);
+
+      if (context_stack_depth > 0)
+	{
+	  /* This is said to happen with SCO.  The old coffread.c
+	     code simply emptied the context stack, so we do the
+	     same.  FIXME: Find out why it is happening.  This is not
+	     believed to happen in most cases (even for coffread.c);
+	     it used to be an abort().  */
+	  static struct complaint msg =
+	  {"Context stack not empty in end_symtab", 0, 0};
+	  complain (&msg);
+	  context_stack_depth = 0;
+	}
+    }
+
+  /* Reordered executables may have out of order pending blocks; if
+     OBJF_REORDERED is true, then sort the pending blocks.  */
+  if ((objfile->flags & OBJF_REORDERED) && pending_blocks)
+    {
+      /* FIXME!  Remove this horrid bubble sort and use merge sort!!! */
+      int swapped;
+      do
+	{
+	  struct pending_block *pb, *pbnext;
+
+	  pb = pending_blocks;
+	  pbnext = pb->next;
+	  swapped = 0;
+
+	  while (pbnext)
+	    {
+	      /* swap blocks if unordered! */
+
+	      if (BLOCK_START (pb->block) < BLOCK_START (pbnext->block))
+		{
+		  struct block *tmp = pb->block;
+		  pb->block = pbnext->block;
+		  pbnext->block = tmp;
+		  swapped = 1;
+		}
+	      pb = pbnext;
+	      pbnext = pbnext->next;
+	    }
+	}
+      while (swapped);
+    }
+
+  /* Cleanup any undefined types that have been left hanging around
+     (this needs to be done before the finish_blocks so that
+     file_symbols is still good).
+  
+     Both cleanup_undefined_types and finish_global_stabs are stabs
+     specific, but harmless for other symbol readers, since on gdb
+     startup or when finished reading stabs, the state is set so these
+     are no-ops.  FIXME: Is this handled right in case of QUIT?  Can
+     we make this cleaner?  */
+
+  cleanup_undefined_types ();
+  finish_global_stabs (objfile);
+
+  if (pending_blocks == NULL
+      && file_symbols == NULL
+      && global_symbols == NULL
+      && have_line_numbers == 0)
+    {
+      /* Ignore symtabs that have no functions with real debugging
+         info.  */
+      blockvector = NULL;
+    }
+  else
+    {
+      /* Define the STATIC_BLOCK & GLOBAL_BLOCK, and build the
+         blockvector.  */
+      finish_block (0, &file_symbols, 0, last_source_start_addr, end_addr,
+		    objfile);
+      finish_block (0, &global_symbols, 0, last_source_start_addr, end_addr,
+		    objfile);
+      blockvector = make_blockvector (objfile);
+    }
+
+#ifndef PROCESS_LINENUMBER_HOOK
+#define PROCESS_LINENUMBER_HOOK()
+#endif
+  PROCESS_LINENUMBER_HOOK ();	/* Needed for xcoff. */
+
+  /* Now create the symtab objects proper, one for each subfile.  */
+  /* (The main file is the last one on the chain.)  */
+
+  for (subfile = subfiles; subfile; subfile = nextsub)
+    {
+      int linetablesize = 0;
+      symtab = NULL;
+
+      /* If we have blocks of symbols, make a symtab. Otherwise, just
+         ignore this file and any line number info in it.  */
+      if (blockvector)
+	{
+	  if (subfile->line_vector)
+	    {
+	      linetablesize = sizeof (struct linetable) +
+	        subfile->line_vector->nitems * sizeof (struct linetable_entry);
+#if 0
+	      /* I think this is artifact from before it went on the
+	         obstack. I doubt we'll need the memory between now
+	         and when we free it later in this function.  */
+	      /* First, shrink the linetable to make more memory.  */
+	      subfile->line_vector = (struct linetable *)
+		xrealloc ((char *) subfile->line_vector, linetablesize);
+#endif
+
+	      /* Like the pending blocks, the line table may be
+	         scrambled in reordered executables.  Sort it if
+	         OBJF_REORDERED is true.  */
+	      if (objfile->flags & OBJF_REORDERED)
+		qsort (subfile->line_vector->item,
+		       subfile->line_vector->nitems,
+		       sizeof (struct linetable_entry), compare_line_numbers);
+	    }
+
+	  /* Now, allocate a symbol table.  */
+	  symtab = allocate_symtab (subfile->name, objfile);
+
+	  /* Fill in its components.  */
+	  symtab->blockvector = blockvector;
+	  if (subfile->line_vector)
+	    {
+	      /* Reallocate the line table on the symbol obstack */
+	      symtab->linetable = (struct linetable *)
+		obstack_alloc (&objfile->symbol_obstack, linetablesize);
+	      memcpy (symtab->linetable, subfile->line_vector, linetablesize);
+	    }
+	  else
+	    {
+	      symtab->linetable = NULL;
+	    }
+	  symtab->block_line_section = section;
+	  if (subfile->dirname)
+	    {
+	      /* Reallocate the dirname on the symbol obstack */
+	      symtab->dirname = (char *)
+		obstack_alloc (&objfile->symbol_obstack,
+			       strlen (subfile->dirname) + 1);
+	      strcpy (symtab->dirname, subfile->dirname);
+	    }
+	  else
+	    {
+	      symtab->dirname = NULL;
+	    }
+	  symtab->free_code = free_linetable;
+	  symtab->free_ptr = NULL;
+
+	  /* Use whatever language we have been using for this
+	     subfile, not the one that was deduced in allocate_symtab
+	     from the filename.  We already did our own deducing when
+	     we created the subfile, and we may have altered our
+	     opinion of what language it is from things we found in
+	     the symbols. */
+	  symtab->language = subfile->language;
+
+	  /* Save the debug format string (if any) in the symtab */
+	  if (subfile->debugformat != NULL)
+	    {
+	      symtab->debugformat = obsavestring (subfile->debugformat,
+				      strlen (subfile->debugformat),
+					  &objfile->symbol_obstack);
+	    }
+
+	  /* All symtabs for the main file and the subfiles share a
+	     blockvector, so we need to clear primary for everything
+	     but the main file.  */
+
+	  symtab->primary = 0;
+	}
+      if (subfile->name != NULL)
+	{
+	  free ((void *) subfile->name);
+	}
+      if (subfile->dirname != NULL)
+	{
+	  free ((void *) subfile->dirname);
+	}
+      if (subfile->line_vector != NULL)
+	{
+	  free ((void *) subfile->line_vector);
+	}
+      if (subfile->debugformat != NULL)
+	{
+	  free ((void *) subfile->debugformat);
+	}
+
+      nextsub = subfile->next;
+      free ((void *) subfile);
+    }
+
+  /* Set this for the main source file.  */
+  if (symtab)
+    {
+      symtab->primary = 1;
+    }
+
+  last_source_file = NULL;
+  current_subfile = NULL;
+
+  return symtab;
+}
+
+/* Push a context block.  Args are an identifying nesting level
+   (checkable when you pop it), and the starting PC address of this
+   context.  */
+
+struct context_stack *
+push_context (int desc, CORE_ADDR valu)
+{
+  register struct context_stack *new;
+
+  if (context_stack_depth == context_stack_size)
+    {
+      context_stack_size *= 2;
+      context_stack = (struct context_stack *)
+	xrealloc ((char *) context_stack,
+	      (context_stack_size * sizeof (struct context_stack)));
+    }
+
+  new = &context_stack[context_stack_depth++];
+  new->depth = desc;
+  new->locals = local_symbols;
+  new->params = param_symbols;
+  new->old_blocks = pending_blocks;
+  new->start_addr = valu;
+  new->name = NULL;
+
+  local_symbols = NULL;
+  param_symbols = NULL;
+
+  return new;
+}
+
+/* Compute a small integer hash code for the given name. */
+
+int
+hashname (char *name)
+{
+  register char *p = name;
+  register int total = p[0];
+  register int c;
+
+  c = p[1];
+  total += c << 2;
+  if (c)
+    {
+      c = p[2];
+      total += c << 4;
+      if (c)
+	{
+	  total += p[3] << 6;
+	}
+    }
+
+  /* Ensure result is positive.  */
+  if (total < 0)
+    {
+      total += (1000 << 6);
+    }
+  return (total % HASHSIZE);
+}
+
+
+void
+record_debugformat (char *format)
+{
+  current_subfile->debugformat = savestring (format, strlen (format));
+}
+
+/* Merge the first symbol list SRCLIST into the second symbol list
+   TARGETLIST by repeated calls to add_symbol_to_list().  This
+   procedure "frees" each link of SRCLIST by adding it to the
+   free_pendings list.  Caller must set SRCLIST to a null list after
+   calling this function.
+
+   Void return. */
+
+void
+merge_symbol_lists (struct pending **srclist, struct pending **targetlist)
+{
+  register int i;
+
+  if (!srclist || !*srclist)
+    return;
+
+  /* Merge in elements from current link.  */
+  for (i = 0; i < (*srclist)->nsyms; i++)
+    add_symbol_to_list ((*srclist)->symbol[i], targetlist);
+
+  /* Recurse on next.  */
+  merge_symbol_lists (&(*srclist)->next, targetlist);
+
+  /* "Free" the current link.  */
+  (*srclist)->next = free_pendings;
+  free_pendings = (*srclist);
+}
+
+/* Initialize anything that needs initializing when starting to read a
+   fresh piece of a symbol file, e.g. reading in the stuff
+   corresponding to a psymtab.  */
+
+void
+buildsym_init ()
+{
+  free_pendings = NULL;
+  file_symbols = NULL;
+  global_symbols = NULL;
+  pending_blocks = NULL;
+}
+
+/* Initialize anything that needs initializing when a completely new
+   symbol file is specified (not just adding some symbols from another
+   file, e.g. a shared library).  */
+
+void
+buildsym_new_init ()
+{
+  buildsym_init ();
+}