Support the combination of -enable-educational-notes and -enable-experimental-diagnostic-formatting

Author: owenv

include/swift/Frontend/PrintingDiagnosticConsumer.h

@@ -37,6 +37,9 @@ class PrintingDiagnosticConsumer : public DiagnosticConsumer {
   // implicitly associated with it. Uses `std::unique_ptr` so that
   // `AnnotatedSourceSnippet` can be forward declared.
   std::unique_ptr<AnnotatedSourceSnippet> currentSnippet;
+  // Educational notes which are buffered until the consumer is finished
+  // constructing a snippet.
+  SmallVector<std::string, 1> BufferedEducationalNotes;
 
 public:
   PrintingDiagnosticConsumer(llvm::raw_ostream &stream = llvm::errs());

lib/Frontend/PrintingDiagnosticConsumer.cpp

@@ -898,6 +898,10 @@ void PrintingDiagnosticConsumer::handleDiagnostic(SourceManager &SM,
       currentSnippet = std::make_unique<AnnotatedSourceSnippet>(SM);
       annotateSnippetWithInfo(SM, Info, *currentSnippet);
     }
+    for (auto path : Info.EducationalNotePaths) {
+      if (auto buffer = SM.getFileSystem()->getBufferForFile(path))
+        BufferedEducationalNotes.push_back(buffer->get()->getBuffer().str());
+    }
   } else {
     printDiagnostic(SM, Info);
 
@@ -929,6 +933,13 @@ void PrintingDiagnosticConsumer::flush(bool includeTrailingBreak) {
     }
     currentSnippet.reset();
   }
+
+  for (auto note : BufferedEducationalNotes) {
+    printMarkdown(note, Stream, ForceColors);
+    Stream << "\n";
+  }
+
+  BufferedEducationalNotes.clear();
 }
 
 bool PrintingDiagnosticConsumer::finishProcessing() {

test/diagnostics/educational-notes.swift

@@ -1,5 +1,6 @@
 // RUN: not %target-swift-frontend -color-diagnostics -enable-educational-notes -diagnostic-documentation-path %S/test-docs/ -typecheck %s 2>&1 | %FileCheck %s --match-full-lines --strict-whitespace
 // RUN: not %target-swift-frontend -no-color-diagnostics -enable-educational-notes -diagnostic-documentation-path %S/test-docs/ -typecheck %s 2>&1 | %FileCheck %s --match-full-lines --strict-whitespace --check-prefix=NO-COLOR
+// RUN: not %target-swift-frontend -enable-experimental-diagnostic-formatting -enable-educational-notes -diagnostic-documentation-path %S/test-docs/ -typecheck %s 2>&1 | %FileCheck %s --check-prefix=CHECK-DESCRIPTIVE
 
 // A diagnostic with no educational notes
 let x = 1 +
@@ -66,3 +67,18 @@ extension (Int, Int) {}
 // NO-COLOR-NEXT:--------------
 // NO-COLOR-NEXT:Header 1
 // NO-COLOR-NEXT:Header 3
+
+// CHECK-DESCRIPTIVE: educational-notes.swift
+// CHECK-DESCRIPTIVE-NEXT:  | // A diagnostic with an educational note
+// CHECK-DESCRIPTIVE-NEXT:  | extension (Int, Int) {}
+// CHECK-DESCRIPTIVE-NEXT:  | ^ error: expected expression after operator
+// CHECK-DESCRIPTIVE-NEXT:  |
+
+// CHECK-DESCRIPTIVE: educational-notes.swift
+// CHECK-DESCRIPTIVE-NEXT:  | // A diagnostic with an educational note
+// CHECK-DESCRIPTIVE-NEXT:  | extension (Int, Int) {}
+// CHECK-DESCRIPTIVE-NEXT:  |           ~~~~~~~~~~
+// CHECK-DESCRIPTIVE-NEXT:  | ^ error: non-nominal type '(Int, Int)' cannot be extended
+// CHECK-DESCRIPTIVE-NEXT:  |
+// CHECK-DESCRIPTIVE-NEXT: Nominal Types
+// CHECK-DESCRIPTIVE-NEXT: -------------