Merge pull request swiftlang#32765 from AnthonyLatsis/readable-dump

[NFC] AssociatedTypeInference: Improve dumping of an inference solution

Author: AnthonyLatsis

lib/Sema/Constraint.cpp

@@ -383,9 +383,6 @@ void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
       auto decl = overload.getDecl();
       decl->dumpRef(Out);
       Out << " : " << decl->getInterfaceType();
-      if (!sm || !decl->getLoc().isValid()) return;
-      Out << " at ";
-      decl->getLoc().print(Out, *sm);
     };
 
     switch (overload.getKind()) {

lib/Sema/TypeCheckProtocolInference.cpp

@@ -75,21 +75,26 @@ void InferredAssociatedTypesByWitness::dump(llvm::raw_ostream &out,
 }
 
 void InferredTypeWitnessesSolution::dump() const {
+  const auto numValueWitnesses = ValueWitnesses.size();
   llvm::errs() << "Type Witnesses:\n";
   for (auto &typeWitness : TypeWitnesses) {
     llvm::errs() << "  " << typeWitness.first->getName() << " := ";
     typeWitness.second.first->print(llvm::errs());
-    llvm::errs() << " value " << typeWitness.second.second << '\n';
+    if (typeWitness.second.second == numValueWitnesses) {
+      llvm::errs() << ", abstract";
+    } else {
+      llvm::errs() << ", inferred from $" << typeWitness.second.second;
+    }
+    llvm::errs() << '\n';
   }
   llvm::errs() << "Value Witnesses:\n";
   for (unsigned i : indices(ValueWitnesses)) {
-    auto &valueWitness = ValueWitnesses[i];
-    llvm::errs() << i << ":  " << (Decl*)valueWitness.first
-    << ' ' << valueWitness.first->getBaseName() << '\n';
-    valueWitness.first->getDeclContext()->printContext(llvm::errs());
-    llvm::errs() << "    for " << (Decl*)valueWitness.second
-    << ' ' << valueWitness.second->getBaseName() << '\n';
-    valueWitness.second->getDeclContext()->printContext(llvm::errs());
+    const auto &valueWitness = ValueWitnesses[i];
+    llvm::errs() << '$' << i << ":\n  ";
+    valueWitness.first->dumpRef(llvm::errs());
+    llvm::errs() << " ->\n  ";
+    valueWitness.second->dumpRef(llvm::errs());
+    llvm::errs() << '\n';
   }
 }