RISC-V: Emit better warning for unknown CSR.

[deliverable/binutils-gdb.git] / gas / config / tc-riscv.c

diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index 454f2831ea1b05dc2a2a9c27cb94a9a962095e42..f65702383cc81b2c430c5e111c37ad2d5a497f7b 100644 (file)
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -993,13 +993,18 @@ normalize_constant_expr (expressionS *ex)
                        - 0x80000000);
 }
 
-/* Fail if an expression is not a constant.  */
+/* Fail if an expression EX is not a constant.  IP is the instruction using EX.
+   MAYBE_CSR is true if the symbol may be an unrecognized CSR name.  */
 
 static void
-check_absolute_expr (struct riscv_cl_insn *ip, expressionS *ex)
+check_absolute_expr (struct riscv_cl_insn *ip, expressionS *ex,
+                    bfd_boolean maybe_csr)
 {
   if (ex->X_op == O_big)
     as_bad (_("unsupported large constant"));
+  else if (maybe_csr && ex->X_op == O_symbol)
+    as_bad (_("unknown CSR `%s'"),
+           S_GET_NAME (ex->X_add_symbol));
   else if (ex->X_op != O_constant)
     as_bad (_("Instruction %s requires absolute expression"),
            ip->insn_mo->name);
@@ -1744,7 +1749,7 @@ rvc_lui:
 
            case '<':           /* Shift amount, 0 - 31.  */
              my_getExpression (imm_expr, s);
-             check_absolute_expr (ip, imm_expr);
+             check_absolute_expr (ip, imm_expr, FALSE);
              if ((unsigned long) imm_expr->X_add_number > 31)
                as_bad (_("Improper shift amount (%lu)"),
                        (unsigned long) imm_expr->X_add_number);
@@ -1755,7 +1760,7 @@ rvc_lui:
 
            case '>':           /* Shift amount, 0 - (XLEN-1).  */
              my_getExpression (imm_expr, s);
-             check_absolute_expr (ip, imm_expr);
+             check_absolute_expr (ip, imm_expr, FALSE);
              if ((unsigned long) imm_expr->X_add_number >= xlen)
                as_bad (_("Improper shift amount (%lu)"),
                        (unsigned long) imm_expr->X_add_number);
@@ -1766,7 +1771,7 @@ rvc_lui:
 
            case 'Z':           /* CSRRxI immediate.  */
              my_getExpression (imm_expr, s);
-             check_absolute_expr (ip, imm_expr);
+             check_absolute_expr (ip, imm_expr, FALSE);
              if ((unsigned long) imm_expr->X_add_number > 31)
                as_bad (_("Improper CSRxI immediate (%lu)"),
                        (unsigned long) imm_expr->X_add_number);
@@ -1781,7 +1786,7 @@ rvc_lui:
              else
                {
                  my_getExpression (imm_expr, s);
-                 check_absolute_expr (ip, imm_expr);
+                 check_absolute_expr (ip, imm_expr, TRUE);
                  if ((unsigned long) imm_expr->X_add_number > 0xfff)
                    as_bad (_("Improper CSR address (%lu)"),
                            (unsigned long) imm_expr->X_add_number);