[PATCH v2 2/2] readelf: Use section names for displaying RELR relocs

[Szabolcs Nagy]

In some cases using section names instead of symbol names for
displaying an address is more useful.

If the symbol falls outside the section where the address is
then likely it is not useful to display the address relative to.

And if symbols are stripped from a binary then printing the
section that contains the address is more useful than printing
<no sym>.
---
v2:
- don't check for '.' in section name.
---
 binutils/readelf.c | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/binutils/readelf.c b/binutils/readelf.c
index 1c0f0254abc..5d1cf9c3388 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -1536,7 +1536,8 @@ uses_msp430x_relocs (Filedata * filedata)
 
 
 static const char *
-get_symbol_at (Elf_Internal_Sym *  symtab,
+get_symbol_at (Filedata *          filedata,
+	       Elf_Internal_Sym *  symtab,
 	       uint64_t            nsyms,
 	       char *              strtab,
 	       uint64_t            where,
@@ -1574,17 +1575,32 @@ get_symbol_at (Elf_Internal_Sym *  symtab,
 	beg = sym + 1;
     }
 
-  if (best == NULL)
+  const char *name;
+
+  /* If there is a section start closer than the found symbol then
+     use that for symbolizing the address.  */
+  Elf_Internal_Shdr *sec = find_section_by_address (filedata, where);
+  if (sec != NULL
+      && where - sec->sh_addr < dist
+      && section_name_valid (filedata, sec))
+    {
+      name = section_name (filedata, sec);
+      dist = where - sec->sh_addr;
+    }
+  else if (best != NULL)
+    name = strtab + best->st_name;
+  else
     return NULL;
 
   if (offset_return != NULL)
     * offset_return = dist;
 
-  return strtab + best->st_name;
+  return name;
 }
 
 static void
-print_relr_addr_and_sym (Elf_Internal_Sym *  symtab,
+print_relr_addr_and_sym (Filedata *          filedata,
+			 Elf_Internal_Sym *  symtab,
 			 uint64_t            nsyms,
 			 char *              strtab,
 			 uint64_t            where)
@@ -1595,7 +1611,7 @@ print_relr_addr_and_sym (Elf_Internal_Sym *  symtab,
   print_vma (where, ZERO_HEX);
   printf ("  ");
 
-  symname = get_symbol_at (symtab, nsyms, strtab, where, & offset);
+  symname = get_symbol_at (filedata, symtab, nsyms, strtab, where, & offset);
 
   if (symname == NULL)
     printf ("<no sym>");
@@ -1869,7 +1885,7 @@ dump_relr_relocations (Filedata *          filedata,
       if ((entry & 1) == 0)
 	{
 	  where = entry;
-	  print_relr_addr_and_sym (symtab, nsyms, strtab, where);
+	  print_relr_addr_and_sym (filedata, symtab, nsyms, strtab, where);
 	  printf ("\n");
 	  where += relr_entsize;
 	}
@@ -1893,13 +1909,13 @@ dump_relr_relocations (Filedata *          filedata,
 		
 		if (first)
 		  {
-		    print_relr_addr_and_sym (symtab, nsyms, strtab, addr);
+		    print_relr_addr_and_sym (filedata, symtab, nsyms, strtab, addr);
 		    first = false;
 		  }
 		else
 		  {
 		    printf (_("\n%*s "), relr_entsize == 4 ? 15 : 23, " ");
-		    print_relr_addr_and_sym (symtab, nsyms, strtab, addr);
+		    print_relr_addr_and_sym (filedata, symtab, nsyms, strtab, addr);
 		  }
 	      }
 
-- 
2.25.1