Re: [PATCH 1/2] MIPS: Compressed PLT/stubs support

[Alan Modra <amodra@gmail.com>]

On Fri, Feb 22, 2013 at 11:28:33AM +1030, Alan Modra wrote:
> Hmm, perhaps a cleaner change would be implement make_msymbol_special
> for ppc64 and move the udata.p special case out of elf_symtab_read?

Like so.

	* elfread.c (elf_symtab_read): Do not use udata.p here to find
	symbol size.
	* ppc64-tdep.c (ppc64_elf_make_msymbol_special): New function.
	* ppc64-tdep.h (ppc64_elf_make_msymbol_special): Declare.
	* ppc-linux-tdep.c (ppc_linux_init_abi): Set up to use the above.
	* ppcfbsd-tdep.c (ppcfbsd_init_abi): Likewise.

Index: gdb/elfread.c
===================================================================
RCS file: /cvs/src/src/gdb/elfread.c,v
retrieving revision 1.145
diff -u -p -r1.145 elfread.c
--- gdb/elfread.c	21 Feb 2013 04:35:21 -0000	1.145
+++ gdb/elfread.c	22 Feb 2013 05:42:53 -0000
@@ -556,21 +556,14 @@ elf_symtab_read (struct objfile *objfile
 
 	  if (msym)
 	    {
-	      /* Pass symbol size field in via BFD.  FIXME!!!  */
-	      elf_symbol_type *elf_sym;
-
 	      /* NOTE: uweigand-20071112: A synthetic symbol does not have an
-		 ELF-private part.  However, in some cases (e.g. synthetic
-		 'dot' symbols on ppc64) the udata.p entry is set to point back
-		 to the original ELF symbol it was derived from.  Get the size
-		 from that symbol.  */
+		 ELF-private part.  */
 	      if (type != ST_SYNTHETIC)
-		elf_sym = (elf_symbol_type *) sym;
-	      else
-		elf_sym = (elf_symbol_type *) sym->udata.p;
-
-	      if (elf_sym)
-		SET_MSYMBOL_SIZE (msym, elf_sym->internal_elf_sym.st_size);
+		{
+		  /* Pass symbol size field in via BFD.  FIXME!!!  */
+		  elf_symbol_type *elf_sym = (elf_symbol_type *) sym;
+		  SET_MSYMBOL_SIZE (msym, elf_sym->internal_elf_sym.st_size);
+		}
 
 	      msym->filename = filesymname;
 	      gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
Index: gdb/ppc-linux-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/ppc-linux-tdep.c,v
retrieving revision 1.143
diff -u -p -r1.143 ppc-linux-tdep.c
--- gdb/ppc-linux-tdep.c	4 Feb 2013 18:40:41 -0000	1.143
+++ gdb/ppc-linux-tdep.c	22 Feb 2013 05:42:53 -0000
@@ -1336,6 +1336,9 @@ ppc_linux_init_abi (struct gdbarch_info 
       set_gdbarch_convert_from_func_ptr_addr
 	(gdbarch, ppc64_convert_from_func_ptr_addr);
 
+      set_gdbarch_elf_make_msymbol_special (gdbarch,
+					    ppc64_elf_make_msymbol_special);
+
       /* Shared library handling.  */
       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets
Index: gdb/ppc64-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/ppc64-tdep.c,v
retrieving revision 1.1
diff -u -p -r1.1 ppc64-tdep.c
--- gdb/ppc64-tdep.c	1 Feb 2013 20:59:08 -0000	1.1
+++ gdb/ppc64-tdep.c	22 Feb 2013 05:42:53 -0000
@@ -22,6 +22,7 @@
 #include "gdbcore.h"
 #include "ppc-tdep.h"
 #include "ppc64-tdep.h"
+#include "elf-bfd.h"
 
 /* Macros for matching instructions.  Note that, since all the
    operands are masked off before they're or-ed into the instruction,
@@ -361,3 +362,17 @@ ppc64_convert_from_func_ptr_addr (struct
 
   return addr;
 }
+
+/* A synthetic 'dot' symbols on ppc64 has the udata.p entry pointing
+   back to the original ELF symbol it was derived from.  Get the size
+   from that symbol.  */
+
+void
+ppc64_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
+{
+  if ((sym->flags & BSF_SYNTHETIC) != 0 && sym->udata.p != NULL)
+    {
+      elf_symbol_type *elf_sym = (elf_symbol_type *) sym->udata.p;
+      SET_MSYMBOL_SIZE (msym, elf_sym->internal_elf_sym.st_size);
+    }
+}
Index: gdb/ppc64-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/ppc64-tdep.h,v
retrieving revision 1.1
diff -u -p -r1.1 ppc64-tdep.h
--- gdb/ppc64-tdep.h	1 Feb 2013 20:59:08 -0000	1.1
+++ gdb/ppc64-tdep.h	22 Feb 2013 05:42:53 -0000
@@ -31,4 +31,6 @@ extern CORE_ADDR ppc64_convert_from_func
 						   CORE_ADDR addr,
 						   struct target_ops *targ);
 
+extern void ppc64_elf_make_msymbol_special (asymbol *,
+					    struct minimal_symbol *);
 #endif /* PPC64_TDEP_H  */
Index: gdb/ppcfbsd-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/ppcfbsd-tdep.c,v
retrieving revision 1.1
diff -u -p -r1.1 ppcfbsd-tdep.c
--- gdb/ppcfbsd-tdep.c	4 Feb 2013 20:48:53 -0000	1.1
+++ gdb/ppcfbsd-tdep.c	22 Feb 2013 05:42:53 -0000
@@ -325,6 +325,9 @@ ppcfbsd_init_abi (struct gdbarch_info in
     {
       set_gdbarch_convert_from_func_ptr_addr
 	(gdbarch, ppc64_convert_from_func_ptr_addr);
+      set_gdbarch_elf_make_msymbol_special (gdbarch,
+					    ppc64_elf_make_msymbol_special);
+
       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 					     svr4_lp64_fetch_link_map_offsets);

-- 
Alan Modra
Australia Development Lab, IBM