[RISCV] Add MC support for .chericap %code(expr)

Author: jrtc27

llvm/lib/MC/MCParser/AsmParser.cpp

@@ -5844,7 +5844,7 @@ bool AsmParser::parseDirectiveCheriCap(SMLoc DirectiveLoc) {
   if (!getTargetParser().isCheri())
     return Error(DirectiveLoc, "'.chericap' requires CHERI");
 
-  if (parseExpression(Expr))
+  if (getTargetParser().parseDataExpr(Expr))
     return true;
 
   int64_t Value;

llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp

@@ -166,6 +166,8 @@ unsigned RISCVELFObjectWriter::getRelocType(const MCFixup &Fixup,
     }
     goto CheriCapability;
   CheriCapability:
+    if (Fixup.getValue()->getKind() == ELF::R_RISCV_CHERI_CAPABILITY_CODE)
+      return ELF::R_RISCV_CHERI_CAPABILITY_CODE;
     return ELF::R_RISCV_CHERI_CAPABILITY;
   case RISCV::fixup_riscv_cheriot_compartment_hi:
     return ELF::R_RISCV_CHERIOT_COMPARTMENT_HI;

llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp

@@ -50,6 +50,7 @@ RISCV::Specifier RISCV::parseSpecifierName(StringRef name) {
       .Case("cheriot_compartment_lo_i", RISCV::S_CHERIOT_COMPARTMENT_LO_I)
       .Case("cheriot_compartment_lo_s", RISCV::S_CHERIOT_COMPARTMENT_LO_S)
       .Case("cheriot_compartment_size", RISCV::S_CHERIOT_COMPARTMENT_SIZE)
+      .Case("code", ELF::R_RISCV_CHERI_CAPABILITY_CODE)
       .Default(0);
 }
 
@@ -105,6 +106,8 @@ StringRef RISCV::getSpecifierName(Specifier S) {
     return "pltpcrel";
   case RISCV::S_QC_ABS20:
     return "qc.abs20";
+  case ELF::R_RISCV_CHERI_CAPABILITY_CODE:
+    return "code";
   }
   llvm_unreachable("Invalid ELF symbol kind");
 }