Merge pull request swiftlang#39057 from slavapestov/minor-rqm-tweaks

RequirementMachine: A few minor tweaks

Author: slavapestov

lib/AST/GenericSignature.cpp

@@ -896,15 +896,19 @@ bool GenericSignatureImpl::areSameTypeParameterInContext(Type type1,
     auto gsbResult = computeViaGSB();
 
     if (gsbResult != rqmResult) {
-      llvm::errs() << "RequirementMachine::areSameTypeParameterInContext() is broken\n";
-      llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
-      llvm::errs() << "First dependent type: "; type1.dump(llvm::errs());
-      llvm::errs() << "Second dependent type: "; type2.dump(llvm::errs());
-      llvm::errs() << "\n";
-      llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
-      llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
-      getRequirementMachine()->dump(llvm::errs());
-      abort();
+      auto firstConcreteType = getConcreteType(type1);
+      auto secondConcreteType = getConcreteType(type2);
+      if (!firstConcreteType->isEqual(secondConcreteType)) {
+        llvm::errs() << "RequirementMachine::areSameTypeParameterInContext() is broken\n";
+        llvm::errs() << "Generic signature: " << GenericSignature(this) << "\n";
+        llvm::errs() << "First dependent type: "; type1.dump(llvm::errs());
+        llvm::errs() << "Second dependent type: "; type2.dump(llvm::errs());
+        llvm::errs() << "\n";
+        llvm::errs() << "GenericSignatureBuilder says: " << gsbResult << "\n";
+        llvm::errs() << "RequirementMachine says: " << rqmResult << "\n";
+        getRequirementMachine()->dump(llvm::errs());
+        abort();
+      }
     }
 
     return rqmResult;

lib/AST/RequirementMachine/GenericSignatureQueries.cpp

@@ -517,7 +517,14 @@ RequirementMachine::getConformanceAccessPath(Type type,
       return found->second;
     }
 
-    assert(CurrentConformanceAccessPaths.size() > 0);
+    if (CurrentConformanceAccessPaths.empty()) {
+      llvm::errs() << "Failed to find conformance access path for ";
+      llvm::errs() << type << " " << protocol->getName() << "\n:";
+      type.dump(llvm::errs());
+      llvm::errs() << "\n";
+      dump(llvm::errs());
+      abort();
+    }
 
     // The buffer consists of all conformance access paths of length N.
     // Swap it out with an empty buffer, and fill it with all paths of

lib/AST/RequirementMachine/RequirementMachine.cpp

@@ -238,6 +238,21 @@ void RewriteSystemBuilder::addRequirement(const Requirement &req,
 
 void RequirementMachine::verify(const MutableTerm &term) const {
 #ifndef NDEBUG
+  // If the term is in the generic parameter domain, ensure we have a valid
+  // generic parameter.
+  if (term.begin()->getKind() == Symbol::Kind::GenericParam) {
+    auto *genericParam = term.begin()->getGenericParam();
+    auto genericParams = Sig.getGenericParams();
+    auto found = std::find(genericParams.begin(),
+                           genericParams.end(),
+                           genericParam);
+    if (found == genericParams.end()) {
+      llvm::errs() << "Bad generic parameter in " << term << "\n";
+      dump(llvm::errs());
+      abort();
+    }
+  }
+
   MutableTerm erased;
 
   // First, "erase" resolved associated types from the term, and try
@@ -305,6 +320,14 @@ void RequirementMachine::dump(llvm::raw_ostream &out) const {
   out << "Requirement machine for " << Sig << "\n";
   System.dump(out);
   Map.dump(out);
+
+  out << "\nConformance access paths:\n";
+  for (auto pair : ConformanceAccessPaths) {
+    out << "- " << pair.first.first << " : ";
+    out << pair.first.second->getName() << " => ";
+    pair.second.print(out);
+    out << "\n";
+  }
 }
 
 RequirementMachine::RequirementMachine(RewriteContext &ctx)