Add a HasAccessMarkers flag to SILFunction.

This allows the verifier to be run before and after marker elimination.

Author: atrick

include/swift/SIL/SILFunction.h

@@ -208,6 +208,10 @@ class SILFunction
   /// after the pass runs, we only see a semantic-arc world.
   bool HasQualifiedOwnership = true;
 
+  /// True if all memory access in this function is demarcated by well-formed
+  /// memory access markers.
+  bool HasAccessMarkers = false;
+
   SILFunction(SILModule &module, SILLinkage linkage, StringRef mangledName,
               CanSILFunctionType loweredType, GenericEnvironment *genericEnv,
               Optional<SILLocation> loc, IsBare_t isBareSILFunction,
@@ -320,6 +324,15 @@ class SILFunction
     HasQualifiedOwnership = false;
   }
 
+  /// Returns true if this function has well-formed access markers describing
+  /// all memory access.
+  bool hasAccessMarkers() const { return HasAccessMarkers; }
+
+  /// Sets the HasAccessMarkers flag to false.
+  void disableAccessMarkers() {
+    HasAccessMarkers = false;
+  }
+
   /// Returns the calling convention used by this entry point.
   SILFunctionTypeRepresentation getRepresentation() const {
     return getLoweredFunctionType()->getRepresentation();

lib/SIL/SILFunction.cpp

@@ -92,6 +92,14 @@ SILFunction::SILFunction(SILModule &Module, SILLinkage Linkage, StringRef Name,
       ClassVisibility(classVisibility), GlobalInitFlag(false),
       InlineStrategy(inlineStrategy), Linkage(unsigned(Linkage)),
       KeepAsPublic(false), EffectsKindAttr(E) {
+
+  // For bootstrapping, enable access markers in raw SIL whenever enforcement is
+  // enabled.
+  if (Module.getStage() == SILStage::Raw
+      && (Module.getOptions().EnforceExclusivityDynamic
+          || Module.getOptions().EnforceExclusivityStatic)) {
+    HasAccessMarkers = true;
+  }
   if (InsertBefore)
     Module.functions.insert(SILModule::iterator(InsertBefore), this);
   else

lib/SIL/SILVerifier.cpp

@@ -1252,6 +1252,8 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
   }
 
   void checkBeginAccessInst(BeginAccessInst *BAI) {
+    require(F.hasAccessMarkers(), "Unexpected begin_access");
+
     auto op = BAI->getOperand();
     requireSameType(BAI->getType(), op->getType(),
                     "result must be same type as operand");
@@ -1286,6 +1288,8 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
   }
 
   void checkEndAccessInst(EndAccessInst *EAI) {
+    require(F.hasAccessMarkers(), "Unexpected end_access");
+
     auto BAI = dyn_cast<BeginAccessInst>(EAI->getOperand());
     require(BAI != nullptr,
             "operand of end_access must be a begin_access");