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* irix5-nat.c, osfsolib.c, solib.c (solib_add): Simplify last

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change by replacing `symbols_added' with `so_last'.
	* mdebugread.c (parse_external, parse_partial_symbols):  Ignore
	global common symbols, they will be resolved by the runtime loader.
	* mdebugread.c (parse_symbol, parse_partial_symbols, cross_ref):
	Handle scSCommon like scCommon symbols.
This commit is contained in:
Peter Schauer
1994-09-11 11:43:40 +00:00
parent dd37f21531
commit 54d478cdba
5 changed files with 234 additions and 24 deletions
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214
gdb/solib.c
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@@ -357,6 +357,189 @@ solib_add_common_symbols (rtc_symp, objfile)
#ifdef SVR4_SHARED_LIBS
#ifdef HANDLE_SVR4_EXEC_EMULATORS
/*
Solaris BCP (the part of Solaris which allows it to run SunOS4
a.out files) throws in another wrinkle. Solaris does not fill
in the usual a.out link map structures when running BCP programs,
the only way to get at them is via groping around in the dynamic
linker.
The dynamic linker and it's structures are located in the shared
C library, which gets run as the executable's "interpreter" by
the kernel.
Note that we can assume nothing about the process state at the time
we need to find these structures. We may be stopped on the first
instruction of the interpreter (C shared library), the first
instruction of the executable itself, or somewhere else entirely
(if we attached to the process for example).
*/
static char *debug_base_symbols[] = {
"r_debug", /* Solaris 2.3 */
"_r_debug", /* Solaris 2.1, 2.2 */
NULL
};
static int
look_for_base PARAMS ((int, CORE_ADDR));
static CORE_ADDR
bfd_lookup_symbol PARAMS ((bfd *, char *));
/*
LOCAL FUNCTION
bfd_lookup_symbol -- lookup the value for a specific symbol
SYNOPSIS
CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
DESCRIPTION
An expensive way to lookup the value of a single symbol for
bfd's that are only temporary anyway. This is used by the
shared library support to find the address of the debugger
interface structures in the shared library.
Note that 0 is specifically allowed as an error return (no
such symbol).
*/
static CORE_ADDR
bfd_lookup_symbol (abfd, symname)
bfd *abfd;
char *symname;
{
unsigned int storage_needed;
asymbol *sym;
asymbol **symbol_table;
unsigned int number_of_symbols;
unsigned int i;
struct cleanup *back_to;
CORE_ADDR symaddr = 0;
storage_needed = bfd_get_symtab_upper_bound (abfd);
if (storage_needed > 0)
{
symbol_table = (asymbol **) xmalloc (storage_needed);
back_to = make_cleanup (free, (PTR)symbol_table);
number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
for (i = 0; i < number_of_symbols; i++)
{
sym = *symbol_table++;
if (STREQ (sym -> name, symname))
{
/* Bfd symbols are section relative. */
symaddr = sym -> value + sym -> section -> vma;
break;
}
}
do_cleanups (back_to);
}
return (symaddr);
}
/*
LOCAL FUNCTION
look_for_base -- examine file for each mapped address segment
SYNOPSYS
static int look_for_base (int fd, CORE_ADDR baseaddr)
DESCRIPTION
This function is passed to proc_iterate_over_mappings, which
causes it to get called once for each mapped address space, with
an open file descriptor for the file mapped to that space, and the
base address of that mapped space.
Our job is to find the debug base symbol in the file that this
fd is open on, if it exists, and if so, initialize the dynamic
linker structure base address debug_base.
Note that this is a computationally expensive proposition, since
we basically have to open a bfd on every call, so we specifically
avoid opening the exec file.
*/
static int
look_for_base (fd, baseaddr)
int fd;
CORE_ADDR baseaddr;
{
bfd *interp_bfd;
CORE_ADDR address = 0;
char **symbolp;
/* If the fd is -1, then there is no file that corresponds to this
mapped memory segment, so skip it. Also, if the fd corresponds
to the exec file, skip it as well. */
if (fd == -1
|| (exec_bfd != NULL
&& fdmatch (fileno ((GDB_FILE *)(exec_bfd -> iostream)), fd)))
{
return (0);
}
/* Try to open whatever random file this fd corresponds to. Note that
we have no way currently to find the filename. Don't gripe about
any problems we might have, just fail. */
if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL)
{
return (0);
}
if (!bfd_check_format (interp_bfd, bfd_object))
{
bfd_close (interp_bfd);
return (0);
}
/* Now try to find our debug base symbol in this file, which we at
least know to be a valid ELF executable or shared library. */
for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
{
address = bfd_lookup_symbol (interp_bfd, *symbolp);
if (address != 0)
{
break;
}
}
if (address == 0)
{
bfd_close (interp_bfd);
return (0);
}
/* Eureka! We found the symbol. But now we may need to relocate it
by the base address. If the symbol's value is less than the base
address of the shared library, then it hasn't yet been relocated
by the dynamic linker, and we have to do it ourself. FIXME: Note
that we make the assumption that the first segment that corresponds
to the shared library has the base address to which the library
was relocated. */
if (address < baseaddr)
{
address += baseaddr;
}
debug_base = address;
bfd_close (interp_bfd);
return (1);
}
#endif /* HANDLE_SVR4_EXEC_EMULATORS */
/*
LOCAL FUNCTION
@@ -391,8 +574,6 @@ elf_locate_base ()
char *bufend;
/* Find the start address of the .dynamic section. */
if (exec_bfd == NULL || bfd_get_flavour (exec_bfd) != bfd_target_elf_flavour)
return 0;
dyninfo_sect = bfd_elf_find_section (exec_bfd, ".dynamic");
if (dyninfo_sect == NULL)
return 0;
@@ -511,11 +692,18 @@ locate_base ()
/* Check to see if we have a currently valid address, and if so, avoid
doing all this work again and just return the cached address. If
we have no cached address, try to locate it in the dynamic info
section. */
section for ELF executables. */
if (debug_base == 0)
{
debug_base = elf_locate_base ();
if (exec_bfd != NULL
&& bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
debug_base = elf_locate_base ();
#ifdef HANDLE_SVR4_EXEC_EMULATORS
/* Try it the hard way for emulated executables. */
else if (inferior_pid != 0)
proc_iterate_over_mappings (look_for_base);
#endif
}
return (debug_base);
@@ -690,9 +878,12 @@ symbol_add_stub (arg)
{
register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */
so -> objfile = symbol_file_add (so -> so_name, so -> from_tty,
(unsigned int) so -> textsection -> addr,
0, 0, 0);
so -> objfile =
symbol_file_add (so -> so_name, so -> from_tty,
(so->textsection == NULL
? 0
: (unsigned int) so -> textsection -> addr),
0, 0, 0);
return (1);
}
@@ -732,9 +923,7 @@ solib_add (arg_string, from_tty, target)
}
/* Add the shared library sections to the section table of the
specified target, if any. We have to do this before reading the
symbol files as symbol_file_add calls reinit_frame_cache and
creating a new frame might access memory in the shared library. */
specified target, if any. */
if (target)
{
/* Count how many new section_table entries there are. */
@@ -805,6 +994,11 @@ solib_add (arg_string, from_tty, target)
}
}
/* Getting new symbols may change our opinion about what is
frameless. */
if (so_last)
reinit_frame_cache ();
/* Calling this once at the end means that we put all the minimal
symbols for commons into the objfile for the last shared library.
Since they are in common, this should not be a problem. If we