Addressing review comments.

Author: David Ungar

lib/AST/DiagnosticConsumer.cpp

@@ -71,8 +71,7 @@ void FileSpecificDiagnosticConsumer::computeConsumersOrderedByRange(
     Optional<unsigned> bufferID = SM.getIDForBufferIdentifier(pair.first);
     assert(bufferID.hasValue() && "consumer registered for unknown file");
     CharSourceRange range = SM.getRangeForBuffer(bufferID.getValue());
-    ConsumersOrderedByRange.emplace_back(range, pair.second ? pair.second.get()
-                                                            : nullptr);
+    ConsumersOrderedByRange.emplace_back(range, pair.second.get());
   }
 
   // Sort the "map" by buffer /end/ location, for use with std::lower_bound
@@ -186,9 +185,8 @@ void FileSpecificDiagnosticConsumer::handleDiagnostic(
     }
   } else if (DiagnosticConsumer *c = specificConsumer.getValue())
     c->handleDiagnostic(SM, Loc, Kind, FormatString, FormatArgs, Info);
-  else {
-    /// suppress non-primary diagnostic in batch mode
-  }
+  else
+    ; // Suppress non-primary diagnostic in batch mode.
 }
 
 bool FileSpecificDiagnosticConsumer::finishProcessing() {

lib/Frontend/FrontendInputsAndOutputs.cpp

@@ -373,9 +373,18 @@ bool FrontendInputsAndOutputs::forEachInputProducingSupplementaryOutput(
 
 bool FrontendInputsAndOutputs::forEachInputNotProducingSupplementaryOutput(
     llvm::function_ref<bool(const InputFile &)> fn) const {
-  // If no primary inputs, compiler is in whole-module-optimzation mode, and
-  // every input can produce supplementary outputs.
-  return hasPrimaryInputs() ? forEachNonPrimaryInput(fn) : false;
+  if (hasPrimaryInputs())
+    return forEachNonPrimaryInput(fn);
+  // If no primary inputs, compiler is in whole-module-optimization mode, and
+  // only the first input can produce supplementary outputs, although all
+  // inputs may contribute.
+  bool isFirst = true;
+  return forEachNonPrimaryInput([&](const InputFile &f) -> bool {
+    if (!isFirst)
+      return fn(f);
+    isFirst = false;
+    return false;
+  });
 }
 
 bool FrontendInputsAndOutputs::hasSupplementaryOutputPath(

test/Misc/serialized-diagnostics-batch-mode-nonprimary-suppression.swift

@@ -23,10 +23,4 @@
 
 
 func test(x: SomeType) {
- // CHECK-MAIN-DAG: serialized-diagnostics-batch-mode.swift:[[@LINE]]:3: error: use of unresolved identifier 'nonexistent'
-  // CHECK-STDERR-DAG: serialized-diagnostics-batch-mode.swift:[[@LINE-1]]:3: error: use of unresolved identifier 'nonexistent'
-
-  // The other file has a similar call.
-  // CHECK-HELPER-DAG: serialized-diagnostics-batch-mode-helper.swift:{{[0-9]+}}:3: error: use of unresolved identifier 'nonexistent'
-  // CHECK-STDERR-DAG: serialized-diagnostics-batch-mode-helper.swift:{{[0-9]+}}:3: error: use of unresolved identifier 'nonexistent'
 }