Don’t output newline for simple_display of DeclContext. And clean up simple_display.

Author: David Ungar

include/swift/AST/DeclContext.h

@@ -588,7 +588,7 @@ class alignas(1 << DeclContextAlignInBits) DeclContext {
 
   void dumpContext() const;
   unsigned printContext(llvm::raw_ostream &OS, unsigned indent = 0,
-                        bool includeAncestors = true) const;
+                        bool onlyAPartialLine = false) const;
 
   // Only allow allocation of DeclContext using the allocator in ASTContext.
   void *operator new(size_t Bytes, ASTContext &C,
@@ -783,15 +783,12 @@ class IterableDeclContext {
 /// avoid ambiguities with Decl* arguments.
 template <typename ParamT, typename = typename std::enable_if<
                                std::is_same<ParamT, DeclContext>::value>::type>
-void simple_display(llvm::raw_ostream &out, const ParamT *x) {
-  if (!std::is_same<ParamT, DeclContext>::value)
-    llvm_unreachable("Template should only be defined for DeclConsts.");
-  const DeclContext *dc = (const DeclContext *)x;
-  if (!dc) {
+void simple_display(llvm::raw_ostream &out, const ParamT *dc) {
+ if (!dc) {
     out << "(null)";
     return;
   }
-  dc->printContext(out, 0, false);
+  dc->printContext(out, 0, true);
 }
 
 } // end namespace swift

lib/AST/DeclContext.cpp

@@ -521,9 +521,9 @@ static unsigned getLineNumber(DCType *DC) {
 }
 
 unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
-                                   const bool includeAncestors) const {
+                                   const bool onlyAPartialLine) const {
   unsigned Depth = 0;
-  if (includeAncestors)
+  if (!onlyAPartialLine)
     if (auto *P = getParent())
       Depth = P->printContext(OS, indent);
 
@@ -645,7 +645,8 @@ unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
   }
   }
 
-  OS << "\n";
+  if (!onlyAPartialLine)
+    OS << "\n";
   return Depth + 1;
 }