gdb/solib: Refactor scan_dyntag

scan_dyntag is unnecessarily duplicated in solib-svr4.c and solib-dsbt.c.

Move this function to solib.c and rename it to gdb_bfd_scan_elf_dyntag.
Also add it to solib.h so it is included in both solib-svr4 and solib-dsbt.

1 files changed, 3 insertions, 101 deletions

diff --git a/gdb/solib-dsbt.c b/gdb/solib-dsbt.c
index 803467d..d7f4b25 100644
--- a/gdb/solib-dsbt.c
+++ b/gdb/solib-dsbt.c
@@ -396,106 +396,6 @@ fetch_loadmap (CORE_ADDR ldmaddr)
 static void dsbt_relocate_main_executable (void);
 static int enable_break (void);
 
-/* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
-   returned and the corresponding PTR is set.  */
-
-static int
-scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr)
-{
-  int arch_size, step, sect_size;
-  long dyn_tag;
-  CORE_ADDR dyn_ptr, dyn_addr;
-  gdb_byte *bufend, *bufstart, *buf;
-  Elf32_External_Dyn *x_dynp_32;
-  Elf64_External_Dyn *x_dynp_64;
-  struct bfd_section *sect;
-
-  if (abfd == NULL)
-    return 0;
-
-  if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
-    return 0;
-
-  arch_size = bfd_get_arch_size (abfd);
-  if (arch_size == -1)
-    return 0;
-
-  /* Find the start address of the .dynamic section.  */
-  sect = bfd_get_section_by_name (abfd, ".dynamic");
-  if (sect == NULL)
-    return 0;
-
-  bool found = false;
-  for (const target_section &target_section
-	 : current_program_space->target_sections ())
-    if (sect == target_section.the_bfd_section)
-      {
-	dyn_addr = target_section.addr;
-	found = true;
-	break;
-      }
-  if (!found)
-    {
-      /* ABFD may come from OBJFILE acting only as a symbol file without being
-	 loaded into the target (see add_symbol_file_command).  This case is
-	 such fallback to the file VMA address without the possibility of
-	 having the section relocated to its actual in-memory address.  */
-
-      dyn_addr = bfd_section_vma (sect);
-    }
-
-  /* Read in .dynamic from the BFD.  We will get the actual value
-     from memory later.  */
-  sect_size = bfd_section_size (sect);
-  buf = bufstart = (gdb_byte *) alloca (sect_size);
-  if (!bfd_get_section_contents (abfd, sect,
-				 buf, 0, sect_size))
-    return 0;
-
-  /* Iterate over BUF and scan for DYNTAG.  If found, set PTR and return.  */
-  step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
-			   : sizeof (Elf64_External_Dyn);
-  for (bufend = buf + sect_size;
-       buf < bufend;
-       buf += step)
-  {
-    if (arch_size == 32)
-      {
-	x_dynp_32 = (Elf32_External_Dyn *) buf;
-	dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
-	dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
-      }
-    else
-      {
-	x_dynp_64 = (Elf64_External_Dyn *) buf;
-	dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
-	dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
-      }
-     if (dyn_tag == DT_NULL)
-       return 0;
-     if (dyn_tag == dyntag)
-       {
-	 /* If requested, try to read the runtime value of this .dynamic
-	    entry.  */
-	 if (ptr)
-	   {
-	     struct type *ptr_type;
-	     gdb_byte ptr_buf[8];
-	     CORE_ADDR ptr_addr;
-
-	     ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
-	     ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8;
-	     if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0)
-	       dyn_ptr = extract_typed_address (ptr_buf, ptr_type);
-	     *ptr = dyn_ptr;
-	   }
-	 return 1;
-       }
-  }
-
-  return 0;
-}
-
 /* See solist.h. */
 
 static int
@@ -565,7 +465,9 @@ lm_base (void)
 			    "lm_base: get addr %x by _GLOBAL_OFFSET_TABLE_.\n",
 			    (unsigned int) addr);
     }
-  else if (scan_dyntag (DT_PLTGOT, current_program_space->exec_bfd (), &addr))
+  else if (gdb_bfd_scan_elf_dyntag (DT_PLTGOT,
+				    current_program_space->exec_bfd (),
+				    &addr, NULL))
     {
       struct int_elf32_dsbt_loadmap *ldm;