Re: Mystified by "Internal error: pc 0x89f21e10 read in psymtab, but not in symtab

Earl Chew
2002-09-16T04:42:59Z

H. J. Lu wrote:
> That patch is broken. See
>
> http://sources.redhat.com/ml/gdb/2002-03/msg00197.html
> http://sources.redhat.com/ml/gdb/2002-03/msg00202.html
>
> Unfortunately, no one seems to care.

I care, I care!

How eerie. I wrote a set of changes this morning, and now comparing
with your changes --- it's uncanny how close they are.

I enclose my patches below for you to peruse. I have some questions
regarding some minor differences:

a. I figured it was better in general to invoke the relocation function
pointer with the section offset structure, and let each
implementation figure out what relocations are required. I
thought that some implementations (in the future) might cache
things other than text locations (eg data locations).

b. In dbxread.c, I initialise the relocate_symtab pointer in
start_psymtab _and_ end_psymtab (where the code loops and allocates
new psymtabs and copies values across).

Your patch doesn't initialise the function pointer here, and I
believe that this will result in an uninitialised field.

Earl
--
--- ../../gdb-5.2.1-orig/gdb/dbxread.c 2002-04-04 13:33:50.000000000 -0800
+++ dbxread.c 2002-09-15 08:52:53.000000000 -0700
@@ -277,6 +277,9 @@

static void read_ofile_symtab (struct partial_symtab *);

+static void dbx_relocate_psymtab (struct partial_symtab *,
+ struct section_offsets *delta);
+
static void dbx_psymtab_to_symtab (struct partial_symtab *);

static void dbx_psymtab_to_symtab_1 (struct partial_symtab *);
@@ -2193,6 +2196,7 @@
TEXTHIGH (result) = result->texthigh;
LDSYMOFF (result) = ldsymoff;
result->read_symtab = dbx_psymtab_to_symtab;
+ result->relocate_symtab = dbx_relocate_psymtab;
SYMBOL_SIZE (result) = symbol_size;
SYMBOL_OFFSET (result) = symbol_table_offset;
STRING_OFFSET (result) = string_table_offset;
@@ -2351,6 +2355,7 @@
subpst->readin = 0;
subpst->symtab = 0;
subpst->read_symtab = pst->read_symtab;
+ subpst->relocate_symtab = pst->relocate_symtab;
}

sort_pst_symbols (pst);
@@ -2436,6 +2441,15 @@
pst->readin = 1;
}

+/* Relocate the cached text offsets for this psymtab. */
+
+static void
+dbx_relocate_psymtab (struct partial_symtab *pst, struct
section_offsets *delta)
+{
+ TEXTLOW (pst) += ANOFFSET (delta, SECT_OFF_TEXT (pst->objfile));
+ TEXTHIGH (pst) += ANOFFSET (delta, SECT_OFF_TEXT (pst->objfile));
+}
+
/* Read in all of the symbols for a given psymtab for real.
Be verbose about it if the user wants that. */

--- ../../gdb-5.2.1-orig/gdb/objfiles.c 2001-12-06 11:59:12.000000000 -0800
+++ objfiles.c 2002-09-15 09:01:35.000000000 -0700
@@ -603,6 +603,9 @@
{
p->textlow += ANOFFSET (delta, SECT_OFF_TEXT (objfile));
p->texthigh += ANOFFSET (delta, SECT_OFF_TEXT (objfile));
+
+ if (p->relocate_symtab)
+ (*p->relocate_symtab) (p, delta);
}
}

--- ../../gdb-5.2.1-orig/gdb/symfile.c 2002-06-22 09:49:34.000000000 -0700
+++ symfile.c 2002-09-15 21:28:55.000000000 -0700
@@ -2338,6 +2338,7 @@
psymtab->section_offsets = section_offsets;
psymtab->textlow = textlow;
psymtab->texthigh = psymtab->textlow; /* default */
+ psymtab->relocate_symtab = 0;
psymtab->globals_offset = global_syms - objfile->global_psymbols.list;
psymtab->statics_offset = static_syms - objfile->static_psymbols.list;
return (psymtab);

--- ../../gdb-5.2.1-orig/gdb/symtab.h 2002-06-28 15:05:48.000000000 -0700
+++ symtab.h 2002-09-15 09:00:32.000000000 -0700
@@ -1029,6 +1029,11 @@

void (*read_symtab) (struct partial_symtab *);

+ /* Pointer to function which will relocate the symtab corresponding to
+ this psymtab. May be 0 if no relocations are required. */
+
+ void (*relocate_symtab) (struct partial_symtab *, struct
section_offsets *);
+
/* Information that lets read_symtab() locate the part of the
symbol table
that this psymtab corresponds to. This information is private
to the
format-dependent symbol reading routines. For further detail
examine