[Diagnostics] Switch swift-syntax diagnostic style to grouped diagnostics

Use the new "grouped diagnostics" feature of the swift-syntax
diagnostic rendering to emit printed diagnostics under the
swift-syntax diagnostic style. This emits macro expansion buffers as
text to the terminal, inset in a box where the macro was expanded, so
that there is more context for understanding how the macro was
expanded and what went wrong inside it.

Author: DougGregor

include/swift/AST/CASTBridging.h

@@ -118,17 +118,18 @@ extern "C" {
 /// information and then must be finished via \c SwiftDiagnostic_finish.
 BridgedDiagnostic SwiftDiagnostic_create(
     void *diagnosticEngine, BridgedDiagnosticSeverity severity,
-    void *_Nullable sourceLoc,
+    const void *_Nullable sourceLoc,
     const uint8_t *_Nullable text, long textLen);
 
 /// Highlight a source range as part of the diagnostic.
 void SwiftDiagnostic_highlight(
-    BridgedDiagnostic diag, void *_Nullable startLoc, void *_Nullable endLoc);
+    BridgedDiagnostic diag, const void *_Nullable startLoc, const void *_Nullable endLoc);
 
 /// Add a Fix-It to replace a source range as part of the diagnostic.
 void SwiftDiagnostic_fixItReplace(
     BridgedDiagnostic diag,
-    void *_Nullable replaceStartLoc, void *_Nullable replaceEndLoc,
+    const void *_Nullable replaceStartLoc,
+    const void *_Nullable replaceEndLoc,
     const uint8_t *_Nullable newText, long newTextLen);
 
 /// Finish the given diagnostic and emit it.

include/swift/AST/DiagnosticEngine.h

@@ -41,6 +41,7 @@ namespace swift {
   class Decl;
   class DeclAttribute;
   class DiagnosticEngine;
+  class GeneratedSourceInfo;
   class SourceManager;
   class ValueDecl;
   class SourceFile;
@@ -1478,6 +1479,10 @@ namespace swift {
 std::pair<unsigned, DeclName>
 getAccessorKindAndNameForDiagnostics(const ValueDecl *D);
 
+/// Retrieve the macro name for a generated source info that represents
+/// a macro expansion.
+DeclName getGeneratedSourceInfoMacroName(const GeneratedSourceInfo &info);
+
 } // end namespace swift
 
 #endif

include/swift/Frontend/PrintingDiagnosticConsumer.h

@@ -22,6 +22,7 @@
 #include "swift/Basic/DiagnosticOptions.h"
 #include "swift/Basic/LLVM.h"
 
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Process.h"
 
@@ -47,10 +48,14 @@ class PrintingDiagnosticConsumer : public DiagnosticConsumer {
   bool SuppressOutput = false;
 
   /// swift-syntax rendering
+
+  /// A queued up source file known to the queued diagnostics.
+  using QueuedBuffer = void *;
+
+  /// The queued diagnostics structure.
   void *queuedDiagnostics = nullptr;
-  void *queuedSourceFile = nullptr;
-  unsigned queuedDiagnosticsBufferID;
-  StringRef queuedBufferName;
+  llvm::DenseMap<unsigned, QueuedBuffer> queuedBuffers;
+  unsigned queuedDiagnosticsOutermostBufferID;
 
 public:
   PrintingDiagnosticConsumer(llvm::raw_ostream &stream = llvm::errs());
@@ -91,6 +96,7 @@ class PrintingDiagnosticConsumer : public DiagnosticConsumer {
   }
 
 private:
+  void queueBuffer(SourceManager &sourceMgr, unsigned bufferID);
   void printDiagnostic(SourceManager &SM, const DiagnosticInfo &Info);
 };
 

lib/AST/CASTBridging.cpp

@@ -20,7 +20,7 @@ inline llvm::ArrayRef<T> getArrayRef(BridgedArrayRef bridged) {
   return {static_cast<const T *>(bridged.data), size_t(bridged.numElements)};
 }
 
-static SourceLoc getSourceLocFromPointer(void *loc) {
+static SourceLoc getSourceLocFromPointer(const void *loc) {
   auto smLoc = llvm::SMLoc::getFromPointer((const char *)loc);
   return SourceLoc(smLoc);
 }
@@ -46,7 +46,7 @@ namespace {
 
 BridgedDiagnostic SwiftDiagnostic_create(
     void *diagnosticEngine, BridgedDiagnosticSeverity severity,
-    void *sourceLocPtr,
+    const void *sourceLocPtr,
     const uint8_t *textPtr, long textLen
 ) {
   StringRef origText{
@@ -81,7 +81,7 @@ BridgedDiagnostic SwiftDiagnostic_create(
 
 /// Highlight a source range as part of the diagnostic.
 void SwiftDiagnostic_highlight(
-    BridgedDiagnostic diagPtr, void *startLocPtr, void *endLocPtr
+    BridgedDiagnostic diagPtr, const void *startLocPtr, const void *endLocPtr
 ) {
   SourceLoc startLoc = getSourceLocFromPointer(startLocPtr);
   SourceLoc endLoc = getSourceLocFromPointer(endLocPtr);
@@ -92,7 +92,8 @@ void SwiftDiagnostic_highlight(
 
 /// Add a Fix-It to replace a source range as part of the diagnostic.
 void SwiftDiagnostic_fixItReplace(
-    BridgedDiagnostic diagPtr, void *replaceStartLocPtr, void *replaceEndLocPtr,
+    BridgedDiagnostic diagPtr,
+    const void *replaceStartLocPtr, const void *replaceEndLocPtr,
     const uint8_t *newTextPtr, long newTextLen) {
 
   SourceLoc startLoc = getSourceLocFromPointer(replaceStartLocPtr);

lib/AST/DiagnosticEngine.cpp

@@ -1316,19 +1316,7 @@ std::vector<Diagnostic> DiagnosticEngine::getGeneratedSourceBufferNotes(
     case GeneratedSourceInfo::PeerMacroExpansion:
     case GeneratedSourceInfo::ConformanceMacroExpansion: {
       SourceRange origRange = expansionNode.getSourceRange();
-      DeclName macroName;
-      if (auto customAttr = generatedInfo->attachedMacroCustomAttr) {
-        // FIXME: How will we handle deserialized custom attributes like this?
-        auto declRefType = dyn_cast<DeclRefTypeRepr>(customAttr->getTypeRepr());
-        macroName = declRefType->getNameRef().getFullName();
-      } else if (auto expansionExpr = dyn_cast_or_null<MacroExpansionExpr>(
-              expansionNode.dyn_cast<Expr *>())) {
-        macroName = expansionExpr->getMacroName().getFullName();
-      } else {
-        auto expansionDecl =
-            cast<MacroExpansionDecl>(expansionNode.get<Decl *>());
-        macroName = expansionDecl->getMacroName().getFullName();
-      }
+      DeclName macroName = getGeneratedSourceInfoMacroName(*generatedInfo);
 
       Diagnostic expansionNote(diag::in_macro_expansion, macroName);
       expansionNote.setLoc(origRange.Start);
@@ -1510,3 +1498,37 @@ swift::getAccessorKindAndNameForDiagnostics(const ValueDecl *D) {
 
   return {NOT_ACCESSOR_INDEX, D->getName()};
 }
+
+DeclName
+swift::getGeneratedSourceInfoMacroName(const GeneratedSourceInfo &info) {
+  ASTNode expansionNode = ASTNode::getFromOpaqueValue(info.astNode);
+  switch (info.kind) {
+  case GeneratedSourceInfo::ExpressionMacroExpansion:
+  case GeneratedSourceInfo::FreestandingDeclMacroExpansion:
+  case GeneratedSourceInfo::AccessorMacroExpansion:
+  case GeneratedSourceInfo::MemberAttributeMacroExpansion:
+  case GeneratedSourceInfo::MemberMacroExpansion:
+  case GeneratedSourceInfo::PeerMacroExpansion:
+  case GeneratedSourceInfo::ConformanceMacroExpansion: {
+    DeclName macroName;
+    if (auto customAttr = info.attachedMacroCustomAttr) {
+      // FIXME: How will we handle deserialized custom attributes like this?
+      auto declRefType = cast<DeclRefTypeRepr>(customAttr->getTypeRepr());
+      return declRefType->getNameRef().getFullName();
+    }
+
+    if (auto expansionExpr = dyn_cast_or_null<MacroExpansionExpr>(
+            expansionNode.dyn_cast<Expr *>())) {
+      return expansionExpr->getMacroName().getFullName();
+    }
+
+    auto expansionDecl =
+        cast<MacroExpansionDecl>(expansionNode.get<Decl *>());
+      return expansionDecl->getMacroName().getFullName();
+  }
+
+  case GeneratedSourceInfo::PrettyPrinted:
+  case GeneratedSourceInfo::ReplacedFunctionBody:
+    return DeclName();
+  }
+}