MIPS/opcodes: Correct mixed MIPS16 and microMIPS disassembly

Mixing MIPS16 and microMIPS code in a single binary isn't usually
supported but GAS happily produces such code if requested.  However it
is not correctly disassembled even if a symbol table is available and
function symbols are correctly anotated with the ISA mode.  This is
because the ELF-header global microMIPS ASE flag takes precedence over
MIPS16 function annotation, causing them to be treated as regular MIPS
code.

Correct the problem by respecting function symbol anotation regardless
of the ELF-header flag.

	binutils/
	* testsuite/binutils-all/mips/mixed-mips16-micromips.d: New test.
	* testsuite/binutils-all/mips/mixed-mips16-micromips.s: New test
	source.
	* testsuite/binutils-all/mips/mips.exp: Run the new test.

	opcodes/
	* mips-dis.c (is_compressed_mode_p): Add `micromips_p' operand,
	replacing references to `micromips_ase' throughout.
	(_print_insn_mips): Don't use file-level microMIPS annotation to
	determine the disassembly mode with the symbol table.

2 files changed, 28 insertions, 17 deletions

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index ce23ca1..680d2d8 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,10 @@
+2016-05-18  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* mips-dis.c (is_compressed_mode_p): Add `micromips_p' operand,
+	replacing references to `micromips_ase' throughout.
+	(_print_insn_mips): Don't use file-level microMIPS annotation to
+	determine the disassembly mode with the symbol table.
+
 2016-05-13  Peter Bergner <bergner@vnet.ibm.com>
 
 	* ppc-opc.c (IMM8): Use PPC_OPERAND_SIGNOPT.
diff --git a/opcodes/mips-dis.c b/opcodes/mips-dis.c
index 535c14a..3f874e7 100644
--- a/opcodes/mips-dis.c
+++ b/opcodes/mips-dis.c
@@ -2268,33 +2268,33 @@ print_insn_micromips (bfd_vma memaddr, struct disassemble_info *info)
 }
 
 /* Return 1 if a symbol associated with the location being disassembled
-   indicates a compressed (MIPS16 or microMIPS) mode.  We iterate over
-   all the symbols at the address being considered assuming if at least
-   one of them indicates code compression, then such code has been
-   genuinely produced here (other symbols could have been derived from
-   function symbols defined elsewhere or could define data).  Otherwise,
-   return 0.  */
+   indicates a compressed mode, either MIPS16 or microMIPS, according to
+   MICROMIPS_P.  We iterate over all the symbols at the address being
+   considered assuming if at least one of them indicates code compression,
+   then such code has been genuinely produced here (other symbols could
+   have been derived from function symbols defined elsewhere or could
+   define data).  Otherwise, return 0.  */
 
 static bfd_boolean
-is_compressed_mode_p (struct disassemble_info *info)
+is_compressed_mode_p (struct disassemble_info *info, bfd_boolean micromips_p)
 {
   int i;
   int l;
 
   for (i = info->symtab_pos, l = i + info->num_symbols; i < l; i++)
     if (((info->symtab[i])->flags & BSF_SYNTHETIC) != 0
-	&& ((!micromips_ase
+	&& ((!micromips_p
 	     && ELF_ST_IS_MIPS16 ((*info->symbols)->udata.i))
-	    || (micromips_ase
+	    || (micromips_p
 		&& ELF_ST_IS_MICROMIPS ((*info->symbols)->udata.i))))
       return 1;
     else if (bfd_asymbol_flavour (info->symtab[i]) == bfd_target_elf_flavour
 	      && info->symtab[i]->section == info->section)
       {
 	elf_symbol_type *symbol = (elf_symbol_type *) info->symtab[i];
-	if ((!micromips_ase
+	if ((!micromips_p
 	     && ELF_ST_IS_MIPS16 (symbol->internal_elf_sym.st_other))
-	    || (micromips_ase
+	    || (micromips_p
 		&& ELF_ST_IS_MICROMIPS (symbol->internal_elf_sym.st_other)))
 	  return 1;
       }
@@ -2313,7 +2313,6 @@ _print_insn_mips (bfd_vma memaddr,
 		  struct disassemble_info *info,
 		  enum bfd_endian endianness)
 {
-  int (*print_insn_compr) (bfd_vma, struct disassemble_info *);
   bfd_byte buffer[INSNLEN];
   int status;
 
@@ -2325,18 +2324,23 @@ _print_insn_mips (bfd_vma memaddr,
   if (info->mach == bfd_mach_mips_micromips)
     return print_insn_micromips (memaddr, info);
 
-  print_insn_compr = !micromips_ase ? print_insn_mips16 : print_insn_micromips;
-
 #if 1
   /* FIXME: If odd address, this is CLEARLY a compressed instruction.  */
   /* Only a few tools will work this way.  */
   if (memaddr & 0x01)
-    return print_insn_compr (memaddr, info);
+    {
+      if (micromips_ase)
+	return print_insn_micromips (memaddr, info);
+      else
+	return print_insn_mips16 (memaddr, info);
+    }
 #endif
 
 #if SYMTAB_AVAILABLE
-  if (is_compressed_mode_p (info))
-    return print_insn_compr (memaddr, info);
+  if (is_compressed_mode_p (info, TRUE))
+    return print_insn_micromips (memaddr, info);
+  if (is_compressed_mode_p (info, FALSE))
+    return print_insn_mips16 (memaddr, info);
 #endif
 
   status = (*info->read_memory_func) (memaddr, buffer, INSNLEN, info);