From 9773cad51939d3980d841876d77064eb7a11002f Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Wed, 10 Mar 2021 19:46:23 -0800
Subject: [PATCH] [RISCV] Add additional checking to tablgen RISCVVEmitter
 requested in D95016.

This errors, but doesn't give source location. We'd need to pass
the Record through several layers to get to the location.

Reviewed By: jrtc27

Differential Revision: https://reviews.llvm.org/D98379
---
 clang/utils/TableGen/RISCVVEmitter.cpp | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/clang/utils/TableGen/RISCVVEmitter.cpp b/clang/utils/TableGen/RISCVVEmitter.cpp
index 3a84590c3a65..49574e45d5bd 100644
--- a/clang/utils/TableGen/RISCVVEmitter.cpp
+++ b/clang/utils/TableGen/RISCVVEmitter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include <numeric>
 
@@ -536,7 +537,7 @@ void RVVType::applyBasicType() {
     ScalarType = ScalarTypeKind::Float;
     break;
   default:
-    llvm_unreachable("Unhandled type code!");
+    PrintFatalError("Unhandled type code!");
   }
   assert(ElementBitwidth != 0 && "Bad element bitwidth!");
 }
@@ -587,7 +588,7 @@ void RVVType::applyModifier(StringRef Transformer) {
     Scale = 0;
     break;
   default:
-    llvm_unreachable("Illegal primitive type transformers!");
+    PrintFatalError("Illegal primitive type transformers!");
   }
   Transformer = Transformer.drop_back();
 
@@ -595,9 +596,15 @@ void RVVType::applyModifier(StringRef Transformer) {
   for (char I : Transformer) {
     switch (I) {
     case 'P':
+      if (IsConstant)
+        PrintFatalError("'P' transformer cannot be used after 'C'");
+      if (IsPointer)
+        PrintFatalError("'P' transformer cannot be used twice");
       IsPointer = true;
       break;
     case 'C':
+      if (IsConstant)
+        PrintFatalError("'C' transformer cannot be used twice");
       IsConstant = true;
       break;
     case 'K':
@@ -614,11 +621,11 @@ void RVVType::applyModifier(StringRef Transformer) {
       break;
     case 'S':
       LMUL = LMULType(0);
-      // Update ElementBitwidth need ot update Scale too.
+      // Update ElementBitwidth need to update Scale too.
       Scale = LMUL.getScale(ElementBitwidth);
       break;
     default:
-      llvm_unreachable("Illegal non-primitive type transformer!");
+      PrintFatalError("Illegal non-primitive type transformer!");
     }
   }
 }