[RISCV] Make use of the required features in BuiltinInfo to store that V extension builtins require 'experimental-v'.

[craig.topper]

Summary

Use that to print the diagnostic in SemaChecking instead of
listing all of the builtins in a switch.

With this is the required features, IR generation will also be
able to error on this. Checking this here allows us to have a RISCV
focused error message.

[khchen]

LGTM!

[HsiangKai]

LGTM.

clang/include/clang/Basic/BuiltinsRISCV.def

 //==- BuiltinsRISCV.def - RISC-V Builtin function database -------*- C++ -*-==//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the RISC-V-specific builtin function database.  Users of
 // this file must define the BUILTIN macro to make use of this information.
 //
 //===----------------------------------------------------------------------===//
 
-#if defined(BUILTIN) && !defined(RISCVV_BUILTIN)
-#define RISCVV_BUILTIN(ID, TYPE, ATTRS) BUILTIN(ID, TYPE, ATTRS)
+#if defined(BUILTIN) && !defined(TARGET_BUILTIN)
+#   define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
+#if defined(TARGET_BUILTIN) && !defined(RISCVV_BUILTIN)
+#define RISCVV_BUILTIN(ID, TYPE, ATTRS) TARGET_BUILTIN(ID, TYPE, ATTRS, "experimental-v")
 #endif
 
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i8m1_vl, "q8Scq8Scq8Scz", "n")
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i8m1_m_vl, "q8Scq8bq8Scq8Scq8Scz", "n")
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i16m1_vl, "q4Ssq4Ssq4Ssz", "n")
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i16m1_m_vl, "q4Ssq4bq4Ssq4Ssq4Ssz", "n")
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i32m1_vl, "q2Siq2Siq2Siz", "n")
 RISCVV_BUILTIN(__builtin_rvv_vadd_vv_i32m1_m_vl, "q2Siq2bq2Siq2Siq2Siz", "n")

clang/lib/Basic/Targets/RISCV.cpp

void RISCVTargetInfo::getTargetDefines(const LangOptions &Opts,
 
   if (HasZvlsseg)
     Builder.defineMacro("__riscv_zvlsseg", "10000");
 }
 
 const Builtin::Info RISCVTargetInfo::BuiltinInfo[] = {
 #define BUILTIN(ID, TYPE, ATTRS)                                               \
   {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
+#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
+    {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, FEATURE},
 #include "clang/Basic/BuiltinsRISCV.def"
 };
 
 ArrayRef<Builtin::Info> RISCVTargetInfo::getTargetBuiltins() const {
   return llvm::makeArrayRef(BuiltinInfo, clang::RISCV::LastTSBuiltin -
                                              Builtin::FirstTSBuiltin);
 }
 

clang/lib/Sema/SemaChecking.cpp

return Diag(ArgExpr->getExprLoc(), diag::err_expr_not_string_literal)
            << ArgExpr->getType();
 
   return false;
 }
 
 bool Sema::CheckRISCVBuiltinFunctionCall(const TargetInfo &TI,
                                          unsigned BuiltinID,
                                          CallExpr *TheCall) {
-  switch (BuiltinID) {
-  default:
-    break;
-#define RISCVV_BUILTIN(ID, TYPE, ATTRS) case RISCV::BI##ID:
-#include "clang/Basic/BuiltinsRISCV.def"
-    if (!TI.hasFeature("experimental-v"))
-      return Diag(TheCall->getBeginLoc(), diag::err_riscvv_builtin_requires_v)
-             << TheCall->getSourceRange();
-    break;
-  }
+  // CodeGenFunction can also detect this, but this gives a better error
+  // message.
+  StringRef Features = Context.BuiltinInfo.getRequiredFeatures(BuiltinID);
+  if (Features.find("experimental-v") != StringRef::npos &&
+      !TI.hasFeature("experimental-v"))
 
   return false;
 }
 
 bool Sema::CheckSystemZBuiltinFunctionCall(unsigned BuiltinID,
                                            CallExpr *TheCall) {
   if (BuiltinID == SystemZ::BI__builtin_tabort) {
     Expr *Arg = TheCall->getArg(0);