[TableGen] Report an error instead of asserting

This gives a nice error if you accidentally try to use an empty list for
the RegTypes of a RegisterClass.

Differential Revision: https://reviews.llvm.org/D78285

diff --git a/llvm/test/TableGen/RegisterClass.td b/llvm/test/TableGen/RegisterClass.td
new file mode 100644 (file)
index 0000000..d81c2df
--- /dev/null
+++ b/llvm/test/TableGen/RegisterClass.td
@@ -0,0 +1,7 @@
+// RUN: not llvm-tblgen -gen-register-bank -I %p/../../include %s 2>&1 | FileCheck %s
+
+include "llvm/Target/Target.td"
+
+def MyTarget : Target;
+def R0 : Register<"r0">;
+def ClassA : RegisterClass<"MyTarget", [], 32, (add R0)>; // CHECK: [[@LINE]]:1: error: RegTypes list must not be empty!

diff --git a/llvm/utils/TableGen/CodeGenRegisters.cpp b/llvm/utils/TableGen/CodeGenRegisters.cpp
index 4584bc7..eeb715d 100644 (file)
--- a/llvm/utils/TableGen/CodeGenRegisters.cpp
+++ b/llvm/utils/TableGen/CodeGenRegisters.cpp
@@ -743,6 +743,8 @@ CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank, Record *R)
       TopoSigs(RegBank.getNumTopoSigs()), EnumValue(-1) {
   GeneratePressureSet = R->getValueAsBit("GeneratePressureSet");
   std::vector<Record*> TypeList = R->getValueAsListOfDefs("RegTypes");
+  if (TypeList.empty())
+    PrintFatalError(R->getLoc(), "RegTypes list must not be empty!");
   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
     Record *Type = TypeList[i];
     if (!Type->isSubClassOf("ValueType"))
@@ -751,7 +753,6 @@ CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank, Record *R)
                           "' does not derive from the ValueType class!");
     VTs.push_back(getValueTypeByHwMode(Type, RegBank.getHwModes()));
   }
-  assert(!VTs.empty() && "RegisterClass must contain at least one ValueType!");
 
   // Allocation order 0 is the full set. AltOrders provides others.
   const SetTheory::RecVec *Elements = RegBank.getSets().expand(R);