[RFA] Getting rid of PC_LOAD_SEGMENT

["Peter.Schauer" <Peter dot Schauer at regent dot e-technik dot tu-muenchen dot de>]

PC_LOAD_SEGMENT is more or less a similar implementation of PC_SOLIB,
resulting in code duplication in stack.c. Historically PC_LOAD_SEGMENT
has been there before PC_SOLIB, but PC_SOLIB is now in more widespread use
and better maintained, so I'd suggest to replace PC_LOAD_SEGMENT with PC_SOLIB.

There are no regressions with the testsuite, but we get better information
from a stack backtrace through shared libraries.

Here is an example from the testsuite:

Without patch:
(gdb) PASS: gdb.base/corefile.exp: print func2::coremaker_local
bt
#0  0xd0170d28 in raise ()
#1  0xd016a454 in abort ()
#2  0x1000061c in func2 () at coremaker.c:107
#3  0x10000664 in func1 () at coremaker.c:113
#4  0x100006bc in main () at coremaker.c:119
#5  0x100001dc in __start ()

With patch:
(gdb) PASS: gdb.base/corefile.exp: print func2::coremaker_local
bt
#0  0xd0170d28 in raise () from /usr/lib/libc.a(shr.o)
#1  0xd016a454 in abort () from /usr/lib/libc.a(shr.o)
#2  0x1000061c in func2 () at coremaker.c:107
#3  0x10000664 in func1 () at coremaker.c:113
#4  0x100006bc in main () at coremaker.c:119
#5  0x100001dc in __start ()


	Get rid of AIX specific PC_LOAD_SEGMENT, replace with PC_SOLIB.
	* xcoffsolib.c (xcoff_solib_address):  Renamed from
	pc_load_segment_name.  Return NULL if address is not in a shared
	library.  Cleanup shared library name construction, using asprintf.
	Format shared library member names consistent with format in exec.c.
	(solib_info):  Format shared library member names consistent with
	format in exec.c.
	* config/rs6000/nm-rs6000.h:  Replace PC_LOAD_SEGMENT with PC_SOLIB,
	using xcoff_solib_address for PC_SOLIB definition.
	* stack.c (print_frame):  Remove PC_LOAD_SEGMENT code, no longer
	needed.

*** ./config/rs6000/nm-rs6000.h.orig	Thu Nov  9 12:05:14 2000
--- ./config/rs6000/nm-rs6000.h	Thu Nov  9 12:04:37 2000
***************
*** 57,66 ****
  struct target_ops;
  extern void xcoff_relocate_core (struct target_ops *);
  
! /* Load segment of a given pc value. */
  
! #define	PC_LOAD_SEGMENT(PC)	pc_load_segment_name(PC)
! extern char *pc_load_segment_name (CORE_ADDR);
  
  /* Return sizeof user struct to callers in less machine dependent routines */
  
--- 57,66 ----
  struct target_ops;
  extern void xcoff_relocate_core (struct target_ops *);
  
! /* If ADDR lies in a shared library, return its name.  */
  
! #define	PC_SOLIB(PC)	xcoff_solib_address(PC)
! extern char *xcoff_solib_address (CORE_ADDR);
  
  /* Return sizeof user struct to callers in less machine dependent routines */
  
*** ./stack.c.orig	Thu Nov  9 11:34:42 2000
--- ./stack.c	Thu Nov  9 11:58:44 2000
***************
*** 623,646 ****
        annotate_frame_source_end ();
      }
  
- #ifdef PC_LOAD_SEGMENT
-   /* If we couldn't print out function name but if can figure out what
-          load segment this pc value is from, at least print out some info
-          about its load segment. */
-   if (!funname)
-     {
-       annotate_frame_where ();
- #ifdef UI_OUT
-       ui_out_wrap_hint (uiout, "  ");
-       ui_out_text (uiout, " from ");
-       ui_out_field_string (uiout, "from", PC_LOAD_SEGMENT (fi->pc));
- #else
-       wrap_here ("  ");
-       printf_filtered (" from %s", PC_LOAD_SEGMENT (fi->pc));
- #endif
-     }
- #endif /* PC_LOAD_SEGMENT */
- 
  #ifdef PC_SOLIB
    if (!funname || (!sal.symtab || !sal.symtab->filename))
      {
--- 623,628 ----
*** ./xcoffsolib.c.orig	Thu Nov  9 20:42:34 2000
--- ./xcoffsolib.c	Sat Nov 11 11:50:32 2000
***************
*** 29,57 ****
  #include "gdb_regex.h"
  
  
! /* Return the module name of a given text address. Note that returned buffer
!    is not persistent. */
  
  char *
! pc_load_segment_name (CORE_ADDR addr)
  {
!   static char buffer[BUFSIZ];
    struct vmap *vp = vmap;
  
!   buffer[0] = buffer[1] = '\0';
!   for (; vp; vp = vp->nxt)
      if (vp->tstart <= addr && addr < vp->tend)
        {
! 	if (*vp->member)
  	  {
! 	    buffer[0] = '(';
! 	    strcat (&buffer[1], vp->member);
! 	    strcat (buffer, ")");
  	  }
! 	strcat (buffer, vp->name);
  	return buffer;
        }
!   return "(unknown load module)";
  }
  
  static void solib_info (char *, int);
--- 29,64 ----
  #include "gdb_regex.h"
  
  
! /* If ADDR lies in a shared library, return its name.
!    Note that returned name points to static data whose content is overwritten
!    by each call.  */
  
  char *
! xcoff_solib_address (CORE_ADDR addr)
  {
!   static char *buffer;
    struct vmap *vp = vmap;
  
!   /* The first vmap entry is for the exec file.  */
! 
!   if (vp == NULL)
!     return NULL;
!   for (vp = vp->nxt; vp; vp = vp->nxt)
      if (vp->tstart <= addr && addr < vp->tend)
        {
! 	if (buffer != NULL)
  	  {
! 	    free (buffer);
! 	    buffer = NULL;
  	  }
! 	asprintf (&buffer, "%s%s%s%s",
! 			   vp->name,
! 			   *vp->member ? "(" : "",
! 			   vp->member,
! 			   *vp->member ? ")" : "");
  	return buffer;
        }
!   return NULL;
  }
  
  static void solib_info (char *, int);
***************
*** 84,93 ****
  			 paddr (vp->tstart),paddr (vp->tend),
  			 paddr (vp->dstart), paddr (vp->dend),
  			 vp->loaded ? "Yes" : "No ",
  			 *vp->member ? "(" : "",
  			 vp->member,
! 			 *vp->member ? ") " : "",
! 			 vp->name);
      }
  }
  
--- 91,100 ----
  			 paddr (vp->tstart),paddr (vp->tend),
  			 paddr (vp->dstart), paddr (vp->dend),
  			 vp->loaded ? "Yes" : "No ",
+ 			 vp->name,
  			 *vp->member ? "(" : "",
  			 vp->member,
! 			 *vp->member ? ")" : "");
      }
  }
  

-- 
Peter Schauer			pes@regent.e-technik.tu-muenchen.de