Move location lookup to RAII object.

Author: David Ungar

include/swift/AST/DiagnosticEngine.h

@@ -28,7 +28,8 @@ namespace swift {
   class DiagnosticEngine;
   class SourceManager;
   class ValueDecl;
-  
+  class SourceFile;
+
   enum class PatternKind : uint8_t;
   enum class SelfAccessKind : uint8_t;
   enum class ReferenceOwnership : uint8_t;
@@ -807,12 +808,11 @@ namespace swift {
     static const char *diagnosticStringFor(const DiagID id);
 
     /// If there is no clear .dia file for a diagnostic, put it in the one
-    /// corresponding to the input buffer ID given here.
+    /// corresponding to the SourceLoc given here.
     /// In particular, in batch mode when a diagnostic is located in
     /// a non-primary file, use this affordance to place it in the .dia
     /// file for the primary that is currently being worked on.
-    void setBufferIndirectlyCausingDiagnosticToInput(
-        unsigned bufferIDE);
+    void setBufferIndirectlyCausingDiagnosticToInput(SourceLoc);
     void resetBufferIndirectlyCausingDiagnostic();
     SourceLoc getDefaultDiagnosticLoc() const {
       return bufferIndirectlyCausingDiagnostic;
@@ -822,14 +822,8 @@ namespace swift {
   class BufferIndirectlyCausingDiagnosticRAII {
   private:
     DiagnosticEngine &Diags;
-
   public:
-    BufferIndirectlyCausingDiagnosticRAII(DiagnosticEngine &Diags,
-                                          unsigned bufferID)
-        : Diags(Diags) {
-      Diags.setBufferIndirectlyCausingDiagnosticToInput(
-          bufferID);
-    }
+    BufferIndirectlyCausingDiagnosticRAII(const SourceFile &SF);
     ~BufferIndirectlyCausingDiagnosticRAII() {
       Diags.resetBufferIndirectlyCausingDiagnostic();
     }

lib/AST/DiagnosticEngine.cpp

@@ -848,17 +848,8 @@ const char *DiagnosticEngine::diagnosticStringFor(const DiagID id) {
 }
 
 void DiagnosticEngine::setBufferIndirectlyCausingDiagnosticToInput(
-    StringRef input) {
-  if (input.empty()) {
-    resetBufferIndirectlyCausingDiagnostic();
-    return;
-  }
-  auto id = SourceMgr.getIDForBufferIdentifier(input);
-  if (!id) {
-    resetBufferIndirectlyCausingDiagnostic();
-    return;
-  }
-  bufferIndirectlyCausingDiagnostic = SourceMgr.getLocForBufferStart(*id);
+    SourceLoc loc) {
+  bufferIndirectlyCausingDiagnostic = loc;
 }
 void DiagnosticEngine::resetBufferIndirectlyCausingDiagnostic() {
   bufferIndirectlyCausingDiagnostic = SourceLoc();
@@ -874,3 +865,13 @@ DiagnosticSuppression::~DiagnosticSuppression() {
   for (auto consumer : consumers)
     diags.addConsumer(*consumer);
 }
+
+BufferIndirectlyCausingDiagnosticRAII::BufferIndirectlyCausingDiagnosticRAII(
+    const SourceFile &SF)
+    : Diags(SF.getASTContext().Diags) {
+  auto id = SF.getBufferID();
+  if (!id)
+    return;
+  auto loc = SF.getASTContext().SourceMgr.getLocForBufferStart(*id);
+  Diags.setBufferIndirectlyCausingDiagnosticToInput(loc);
+}

lib/FrontendTool/FrontendTool.cpp

@@ -1221,7 +1221,7 @@ static bool performCompileStepsPostSILGen(
 
   Optional<BufferIndirectlyCausingDiagnosticRAII> ricd;
   if (auto *SF = MSF.dyn_cast<SourceFile *>())
-    ricd.emplace(Context.Diags, SF->getBufferID());
+    ricd.emplace(*SF);
 
   if (Stats)
     countStatsPostSILGen(*Stats, *SM);

lib/Sema/TypeChecker.cpp

@@ -460,8 +460,7 @@ void swift::performTypeChecking(SourceFile &SF, TopLevelContext &TLC,
     return;
 
   auto &Ctx = SF.getASTContext();
-  BufferIndirectlyCausingDiagnosticRAII cpr(SF.getASTContext().Diags,
-                                            SF.getBufferID());
+  BufferIndirectlyCausingDiagnosticRAII cpr(SF);
 
   // Make sure we have a type checker.
   TypeChecker &TC = createTypeChecker(Ctx);