2002-10-08 Petr Sorfa <petrs@caldera.com>

Revised and re-submitted by John Wolfe <jlw@caldera.com>

Move the Dwarf 2 abbrev table to a per-compilation-unit structure,
so we can work on more than one compilation unit at a time.  This
helps prepare GDB to handle inter-CU die references.
* dwarf2read.c (ABBREV_HASH_SIZE): moved definition forward in
the code to be defined before struct comp_unit_head.
(comp_unit_head): Added new members - offset, cu_head,
begin_die, next and dwarf2_abbrevs.
(dwarf2_abbrevs): Removed single static var; now member of
struct comp_unit_head.
dwarf2_build_psymtabs_hard): Complete new struct comp_unit_head
members.
(psymtab_to_symtab_1): Changed to work with the new
struct comp_unit_head.
(dwarf2_read_abbrevs): Now accepts a cu_header parameter and
constructs the dwarf2_abbrevs[] inside the cu_header.
(dwarf2_empty_abbrev_table): Now expects a ptr to a
dwarf2_abbrev table to clean up.
(dwarf2_lookup_abbrev): Now accepts a cu_header parameter and
handling of dwarf2_abbrevs inside the cu_header.
(read_partial_die): Now supports the call to the new
dwarf2_lookup_abbrev.
(read_full_die): Now supports the call to the new
dwarf2_lookup_abbrev.

1 files changed, 58 insertions, 27 deletions

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index b62b0282b3f..8edbd869669 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -162,6 +162,11 @@ unsigned int dwarf_eh_frame_size;
 
 /* local data types */
 
+/* We hold several abbreviation tables in memory at the same time. */
+#ifndef ABBREV_HASH_SIZE
+#define ABBREV_HASH_SIZE 121
+#endif
+
 /* The data in a compilation unit header, after target2host
    translation, looks like this.  */
 struct comp_unit_head
@@ -174,6 +179,29 @@ struct comp_unit_head
     unsigned int offset_size;	/* size of file offsets; either 4 or 8 */
     unsigned int initial_length_size; /* size of the length field; either
                                          4 or 12 */
+
+    /* Offset to the first byte of this compilation unit header in the 
+     * .debug_info section, for resolving relative reference dies. */
+
+    unsigned int offset;
+
+    /* Pointer to this compilation unit header in the .debug_info
+     * section */
+
+    char *cu_head_ptr;
+
+    /* Pointer to the first die of this compilatio unit.  This will
+     * be the first byte following the compilation unit header. */
+
+    char *first_die_ptr;
+
+    /* Pointer to the next compilation unit header in the program. */
+
+    struct comp_unit_head *next;
+
+    /* DWARF abbreviation table associated with this compilation unit */
+
+    struct abbrev_info *dwarf2_abbrevs[ABBREV_HASH_SIZE];
   };
 
 /* The line number information for a compilation unit (found in the
@@ -312,17 +340,10 @@ struct dwarf_block
     char *data;
   };
 
-/* We only hold one compilation unit's abbrevs in
-   memory at any one time.  */
-#ifndef ABBREV_HASH_SIZE
-#define ABBREV_HASH_SIZE 121
-#endif
 #ifndef ATTR_ALLOC_CHUNK
 #define ATTR_ALLOC_CHUNK 4
 #endif
 
-static struct abbrev_info *dwarf2_abbrevs[ABBREV_HASH_SIZE];
-
 /* A hash table of die offsets for following references.  */
 #ifndef REF_HASH_SIZE
 #define REF_HASH_SIZE 1021
@@ -686,11 +707,12 @@ static void psymtab_to_symtab_1 (struct partial_symtab *);
 
 char *dwarf2_read_section (struct objfile *, file_ptr, unsigned int);
 
-static void dwarf2_read_abbrevs (bfd *, unsigned int);
+static void dwarf2_read_abbrevs (bfd *abfd, struct comp_unit_head *cu_header);
 
 static void dwarf2_empty_abbrev_table (PTR);
 
-static struct abbrev_info *dwarf2_lookup_abbrev (unsigned int);
+static struct abbrev_info *dwarf2_lookup_abbrev (unsigned int,
+                                         const struct comp_unit_head *cu_header);
 
 static char *read_partial_die (struct partial_die_info *,
 			       bfd *, char *,
@@ -1211,9 +1233,14 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline)
 		 (long) (beg_of_comp_unit - dwarf_info_buffer));
 	  return;
 	}
+      /* Complete the cu_header */
+      cu_header.offset = beg_of_comp_unit - dwarf_info_buffer;
+      cu_header.first_die_ptr = info_ptr;
+      cu_header.cu_head_ptr = beg_of_comp_unit;
+
       /* Read the abbrevs for this compilation unit into a table */
-      dwarf2_read_abbrevs (abfd, cu_header.abbrev_offset);
-      make_cleanup (dwarf2_empty_abbrev_table, NULL);
+      dwarf2_read_abbrevs (abfd, &cu_header);
+      make_cleanup (dwarf2_empty_abbrev_table, cu_header.dwarf2_abbrevs);
 
       /* Read the compilation unit die */
       info_ptr = read_partial_die (&comp_unit_die, abfd, info_ptr,
@@ -1560,8 +1587,8 @@ psymtab_to_symtab_1 (struct partial_symtab *pst)
   info_ptr = read_comp_unit_head (&cu_header, info_ptr, abfd);
 
   /* Read the abbrevs for this compilation unit  */
-  dwarf2_read_abbrevs (abfd, cu_header.abbrev_offset);
-  make_cleanup (dwarf2_empty_abbrev_table, NULL);
+  dwarf2_read_abbrevs (abfd, &cu_header);
+  make_cleanup (dwarf2_empty_abbrev_table, cu_header.dwarf2_abbrevs);
 
   dies = read_comp_unit (info_ptr, abfd, &cu_header);
 
@@ -3345,17 +3372,18 @@ dwarf2_read_section (struct objfile *objfile, file_ptr offset,
    in a hash table.  */
 
 static void
-dwarf2_read_abbrevs (bfd *abfd, unsigned int offset)
+dwarf2_read_abbrevs (bfd *abfd, struct comp_unit_head *cu_header)
 {
   char *abbrev_ptr;
   struct abbrev_info *cur_abbrev;
   unsigned int abbrev_number, bytes_read, abbrev_name;
   unsigned int abbrev_form, hash_number;
 
-  /* empty the table */
-  dwarf2_empty_abbrev_table (NULL);
+  /* Initialize dwarf2 abbrevs */
+  memset (cu_header->dwarf2_abbrevs, 0,
+          ABBREV_HASH_SIZE*sizeof (struct abbrev_info *));
 
-  abbrev_ptr = dwarf_abbrev_buffer + offset;
+  abbrev_ptr = dwarf_abbrev_buffer + cu_header->abbrev_offset;
   abbrev_number = read_unsigned_leb128 (abfd, abbrev_ptr, &bytes_read);
   abbrev_ptr += bytes_read;
 
@@ -3394,8 +3422,8 @@ dwarf2_read_abbrevs (bfd *abfd, unsigned int offset)
 	}
 
       hash_number = abbrev_number % ABBREV_HASH_SIZE;
-      cur_abbrev->next = dwarf2_abbrevs[hash_number];
-      dwarf2_abbrevs[hash_number] = cur_abbrev;
+      cur_abbrev->next = cu_header->dwarf2_abbrevs[hash_number];
+      cu_header->dwarf2_abbrevs[hash_number] = cur_abbrev;
 
       /* Get next abbreviation.
          Under Irix6 the abbreviations for a compilation unit are not
@@ -3409,7 +3437,7 @@ dwarf2_read_abbrevs (bfd *abfd, unsigned int offset)
 	break;
       abbrev_number = read_unsigned_leb128 (abfd, abbrev_ptr, &bytes_read);
       abbrev_ptr += bytes_read;
-      if (dwarf2_lookup_abbrev (abbrev_number) != NULL)
+      if (dwarf2_lookup_abbrev (abbrev_number, cu_header) != NULL)
 	break;
     }
 }
@@ -3418,15 +3446,18 @@ dwarf2_read_abbrevs (bfd *abfd, unsigned int offset)
 
 /* ARGSUSED */
 static void
-dwarf2_empty_abbrev_table (PTR ignore)
+dwarf2_empty_abbrev_table (PTR ptr_to_abbrevs_table)
 {
   int i;
   struct abbrev_info *abbrev, *next;
+  struct abbrev_info **abbrevs;
+
+  abbrevs = (struct abbrev_info **)ptr_to_abbrevs_table;
 
   for (i = 0; i < ABBREV_HASH_SIZE; ++i)
     {
       next = NULL;
-      abbrev = dwarf2_abbrevs[i];
+      abbrev = abbrevs[i];
       while (abbrev)
 	{
 	  next = abbrev->next;
@@ -3434,20 +3465,20 @@ dwarf2_empty_abbrev_table (PTR ignore)
 	  xfree (abbrev);
 	  abbrev = next;
 	}
-      dwarf2_abbrevs[i] = NULL;
+      abbrevs[i] = NULL;
     }
 }
 
 /* Lookup an abbrev_info structure in the abbrev hash table.  */
 
 static struct abbrev_info *
-dwarf2_lookup_abbrev (unsigned int number)
+dwarf2_lookup_abbrev (unsigned int number, const struct comp_unit_head *cu_header)
 {
   unsigned int hash_number;
   struct abbrev_info *abbrev;
 
   hash_number = number % ABBREV_HASH_SIZE;
-  abbrev = dwarf2_abbrevs[hash_number];
+  abbrev = cu_header->dwarf2_abbrevs[hash_number];
 
   while (abbrev)
     {
@@ -3479,7 +3510,7 @@ read_partial_die (struct partial_die_info *part_die, bfd *abfd,
   if (!abbrev_number)
     return info_ptr;
 
-  abbrev = dwarf2_lookup_abbrev (abbrev_number);
+  abbrev = dwarf2_lookup_abbrev (abbrev_number, cu_header);
   if (!abbrev)
     {
       error ("Dwarf Error: Could not find abbrev number %d.", abbrev_number);
@@ -3623,7 +3654,7 @@ read_full_die (struct die_info **diep, bfd *abfd, char *info_ptr,
       return info_ptr;
     }
 
-  abbrev = dwarf2_lookup_abbrev (abbrev_number);
+  abbrev = dwarf2_lookup_abbrev (abbrev_number, cu_header);
   if (!abbrev)
     {
       error ("Dwarf Error: could not find abbrev number %d.", abbrev_number);