binutils: add ELF e_flag to signify RVC code

binutils/gas/config/tc-riscv.c

@@ -1930,6 +1930,9 @@ riscv_after_parse_args (void)
 {
   if (riscv_subsets == NULL)
     riscv_set_arch ("RVIMAFDXcustom");
+
+  if (riscv_opts.rvc)
+    elf_flags |= EF_RISCV_RVC;
 }
 
 void

binutils/include/elf/riscv.h

@@ -80,6 +80,9 @@ END_RELOC_NUMBERS (R_RISCV_max)
 
 /* Processor specific flags for the ELF header e_flags field.  */
 
+/* File may contain compressed instructions.  */
+#define EF_RISCV_RVC 0x0001
+
 /* Custom flag definitions. */
 
 #define EF_RISCV_EXT_MASK 0xffff

patches/binutils

@@ -219,22 +219,26 @@
      case EM_RL78:		return "Renesas RL78";
      case EM_RX:			return "Renesas RX";
      case EM_METAG:		return "Imagination Technologies Meta processor architecture";
-@@ -2951,6 +2958,14 @@ get_machine_flags (unsigned e_flags, uns
+@@ -2951,6 +2958,18 @@ get_machine_flags (unsigned e_flags, uns
  	  decode_NDS32_machine_flags (e_flags, buf, sizeof buf);
  	  break;
  
 +	case EM_RISCV:
 +          {
-+            unsigned int riscv_extension = EF_GET_RISCV_EXT(e_flags);
-+            strcat (buf, ", ");
-+            strcat (buf, riscv_elf_flag_to_name (riscv_extension));
++	    if (e_flags & EF_RISCV_RVC)
++	      strcat (buf, ", RVC");
++
++	    if (!EF_GET_RISCV_EXT (e_flags))
++	      break;
++	    strcat (buf, ", ");
++	    strcat (buf, riscv_elf_flag_to_name (EF_GET_RISCV_EXT (e_flags)));
 +          }
 +	  break;
 +
  	case EM_SH:
  	  switch ((e_flags & EF_SH_MACH_MASK))
  	    {
-@@ -10789,6 +10804,8 @@ is_32bit_abs_reloc (unsigned int reloc_t
+@@ -10789,6 +10808,8 @@ is_32bit_abs_reloc (unsigned int reloc_t
        return reloc_type == 1; /* R_PPC64_ADDR32.  */
      case EM_PPC:
        return reloc_type == 1; /* R_PPC_ADDR32.  */
@@ -243,7 +247,7 @@
      case EM_RL78:
        return reloc_type == 1; /* R_RL78_DIR32.  */
      case EM_RX:
-@@ -10924,6 +10941,8 @@ is_64bit_abs_reloc (unsigned int reloc_t
+@@ -10924,6 +10945,8 @@ is_64bit_abs_reloc (unsigned int reloc_t
        return reloc_type == 80; /* R_PARISC_DIR64.  */
      case EM_PPC64:
        return reloc_type == 38; /* R_PPC64_ADDR64.  */
@@ -252,7 +256,7 @@
      case EM_SPARC32PLUS:
      case EM_SPARCV9:
      case EM_SPARC:
-@@ -11072,6 +11091,7 @@ is_none_reloc (unsigned int reloc_type)
+@@ -11072,6 +11095,7 @@ is_none_reloc (unsigned int reloc_type)
      case EM_ADAPTEVA_EPIPHANY:
      case EM_PPC:     /* R_PPC_NONE.  */
      case EM_PPC64:   /* R_PPC64_NONE.  */