[binutils-gdb] opcodes/csky: return the default disassembler when there is no bfd

[LifangXia]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c568ac5ff708eebf6ef424e5863d3dbd874a3f62

commit c568ac5ff708eebf6ef424e5863d3dbd874a3f62
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date:   Wed Sep 16 10:12:39 2020 +0100

    opcodes/csky: return the default disassembler when there is no bfd
    
    The disassembler function should return a valid disassembler function
    even when there is no BFD present.  This is implied (I believe) by the
    comment in dis-asm.h which says the BFD may be NULL.  Further, it
    makes sense when considering that the disassembler is used in GDB, and
    GDB may connect to a target and perform debugging even without a BFD
    being supplied.
    
    This commit makes the csky_get_disassembler function return the
    default disassembler configuration when no bfd is supplied, this is
    the same default configuration as is used when a BFD is supplied, but
    the BFD has no attributes section.
    
    Before the change configuring GDB with --enable-targets=all and
    running the tests gdb.base/all-architectures-2.exp results in many
    errors, but after this change there are no failures.
    
    opcodes/ChangeLog:
    
            * csky-dis.c (csky_get_disassembler): Don't return NULL when there
            is no BFD.

Diff:
---
 opcodes/ChangeLog  |  5 +++++
 opcodes/csky-dis.c | 32 +++++++++++++++++---------------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 532dde412e4..624351131a8 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-16  Andrew Burgess <andrew.burgess@embecosm.com>
+
+	* csky-dis.c (csky_get_disassembler): Don't return NULL when there
+	is no BFD.
+
 2020-09-16  Alan Modra  <amodra@gmail.com>
 
 	* ppc-dis.c (ppc_symbol_is_valid): Adjust elf_symbol_from invocation.
diff --git a/opcodes/csky-dis.c b/opcodes/csky-dis.c
index ba0f4605f54..a28160b984e 100644
--- a/opcodes/csky-dis.c
+++ b/opcodes/csky-dis.c
@@ -239,23 +239,25 @@ csky_get_disassembler (bfd *abfd)
   obj_attribute *attr;
   const char *sec_name = NULL;
   if (!abfd)
-    return NULL;
-
-  mach_flag = elf_elfheader (abfd)->e_flags;
-
-  sec_name = get_elf_backend_data (abfd)->obj_attrs_section;
-  /* Skip any input that hasn't attribute section.
-     This enables to link object files without attribute section with
-     any others.  */
-  if (bfd_get_section_by_name (abfd, sec_name) != NULL)
+    dis_info.isa = CSKY_DEFAULT_ISA;
+  else
     {
-      attr = elf_known_obj_attributes_proc (abfd);
-      dis_info.isa = attr[Tag_CSKY_ISA_EXT_FLAGS].i;
-      dis_info.isa <<= 32;
-      dis_info.isa |= attr[Tag_CSKY_ISA_FLAGS].i;
+      mach_flag = elf_elfheader (abfd)->e_flags;
+
+      sec_name = get_elf_backend_data (abfd)->obj_attrs_section;
+      /* Skip any input that hasn't attribute section.
+         This enables to link object files without attribute section with
+         any others.  */
+      if (bfd_get_section_by_name (abfd, sec_name) != NULL)
+        {
+          attr = elf_known_obj_attributes_proc (abfd);
+          dis_info.isa = attr[Tag_CSKY_ISA_EXT_FLAGS].i;
+          dis_info.isa <<= 32;
+          dis_info.isa |= attr[Tag_CSKY_ISA_FLAGS].i;
+        }
+      else
+        dis_info.isa = CSKY_DEFAULT_ISA;
     }
-  else
-    dis_info.isa = CSKY_DEFAULT_ISA;
 
    return print_insn_csky;
 }