SIL: add some asserts to catch broken enum ASTs

Author: eeckstein

include/swift/SIL/SILBuilder.h

@@ -1728,6 +1728,9 @@ class SILBuilder {
                        EnumElementDecl *Element, SILType Ty,
                        ValueOwnershipKind forwardingOwnershipKind) {
     ASSERT(isLoadableOrOpaque(Ty));
+    // Assert that this works and does not crash.
+    (void)getModule().getCaseIndex(Element);
+
     return insert(new (getModule())
                       EnumInst(getSILDebugLocation(Loc), Operand, Element, Ty,
                                forwardingOwnershipKind));
@@ -1751,6 +1754,9 @@ class SILBuilder {
                                                SILValue Operand,
                                                EnumElementDecl *Element,
                                                SILType Ty) {
+    // Assert that this works and does not crash.
+    (void)getModule().getCaseIndex(Element);
+
     return insert(new (getModule()) InitEnumDataAddrInst(
         getSILDebugLocation(Loc), Operand, Element, Ty));
   }
@@ -1776,6 +1782,9 @@ class SILBuilder {
                           EnumElementDecl *Element, SILType Ty,
                           ValueOwnershipKind forwardingOwnershipKind) {
     ASSERT(isLoadableOrOpaque(Ty));
+    // Assert that this works and does not crash.
+    (void)getModule().getCaseIndex(Element);
+
     return insert(new (getModule()) UncheckedEnumDataInst(
         getSILDebugLocation(Loc), Operand, Element, Ty,
         forwardingOwnershipKind));
@@ -1791,6 +1800,9 @@ class SILBuilder {
   UncheckedTakeEnumDataAddrInst *
   createUncheckedTakeEnumDataAddr(SILLocation Loc, SILValue Operand,
                                   EnumElementDecl *Element, SILType Ty) {
+    // Assert that this works and does not crash.
+    (void)getModule().getCaseIndex(Element);
+
     return insert(new (getModule()) UncheckedTakeEnumDataAddrInst(
         getSILDebugLocation(Loc), Operand, Element, Ty));
   }
@@ -1805,6 +1817,9 @@ class SILBuilder {
 
   InjectEnumAddrInst *createInjectEnumAddr(SILLocation Loc, SILValue Operand,
                                            EnumElementDecl *Element) {
+    // Assert that this works and does not crash.
+    (void)getModule().getCaseIndex(Element);
+
     return insert(new (getModule()) InjectEnumAddrInst(
         getSILDebugLocation(Loc), Operand, Element));
   }

lib/SIL/IR/SILModule.cpp

@@ -804,7 +804,8 @@ unsigned SILModule::getCaseIndex(EnumElementDecl *enumElement) {
     }
     ++idx;
   }
-  llvm_unreachable("enum element not found in enum decl");
+  ASSERT(false && "enum element not found in enum decl, broken AST?");
+  return 0;
 }
 
 void SILModule::notifyAddedInstruction(SILInstruction *inst) {