[llvm] r321217 - Do not generate an empty switch statement as it causes MSVC to issue diagnostics about switch statements without case or default labels.

[Aaron Ballman via llvm-commits]

Author: aaronballman
Date: Wed Dec 20 12:09:30 2017
New Revision: 321217

URL: http://llvm.org/viewvc/llvm-project?rev=321217&view=rev
Log:
Do not generate an empty switch statement as it causes MSVC to issue diagnostics about switch statements without case or default labels.

Modified:
    llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp

Modified: llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp?rev=321217&r1=321216&r2=321217&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp Wed Dec 20 12:09:30 2017
@@ -3551,8 +3551,10 @@ void GlobalISelEmitter::emitImmPredicate
   }
 
   OS << "bool " << Target.getName() << "InstructionSelector::testImmPredicate_"
-     << TypeIdentifier << "(unsigned PredicateID, " << Type << " Imm) const {\n"
-     << "  switch (PredicateID) {\n";
+     << TypeIdentifier << "(unsigned PredicateID, " << Type
+     << " Imm) const {\n";
+  if (!MatchedRecords.empty())
+    OS << "  switch (PredicateID) {\n";
   for (const auto *Record : MatchedRecords) {
     OS << "  case GIPFP_" << TypeIdentifier << "_Predicate_"
        << Record->getName() << ": {\n"
@@ -3561,8 +3563,9 @@ void GlobalISelEmitter::emitImmPredicate
        << "    return false;\n"
        << "  }\n";
   }
-  OS << "  }\n"
-     << "  llvm_unreachable(\"Unknown predicate\");\n"
+  if (!MatchedRecords.empty())
+    OS << "  }\n";
+  OS << "  llvm_unreachable(\"Unknown predicate\");\n"
      << "  return false;\n"
      << "}\n";
 }