Revert "Fix OOM in FormatDiagnostic" (#108838)

Reverting due to build failures found in #108187

1 files changed, 13 insertions, 6 deletions

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index e950ad6..d567de7 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -1589,7 +1589,7 @@ LangAS Sema::getDefaultCXXMethodAddrSpace() const {
   return LangAS::Default;
 }
 
-void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
+void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
   // FIXME: It doesn't make sense to me that DiagID is an incoming argument here
   // and yet we also use the current diag ID on the DiagnosticsEngine. This has
   // been made more painfully obvious by the refactor that introduced this
@@ -1597,9 +1597,9 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
   // eliminated. If it truly cannot be (for example, there is some reentrancy
   // issue I am not seeing yet), then there should at least be a clarifying
   // comment somewhere.
-  Diagnostic DiagInfo(&Diags, DB);
   if (std::optional<TemplateDeductionInfo *> Info = isSFINAEContext()) {
-    switch (DiagnosticIDs::getDiagnosticSFINAEResponse(DiagInfo.getID())) {
+    switch (DiagnosticIDs::getDiagnosticSFINAEResponse(
+              Diags.getCurrentDiagID())) {
     case DiagnosticIDs::SFINAE_Report:
       // We'll report the diagnostic below.
       break;
@@ -1612,11 +1612,13 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
       // Make a copy of this suppressed diagnostic and store it with the
       // template-deduction information.
       if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
+        Diagnostic DiagInfo(&Diags);
         (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
                        PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
       }
 
       Diags.setLastDiagnosticIgnored(true);
+      Diags.Clear();
       return;
 
     case DiagnosticIDs::SFINAE_AccessControl: {
@@ -1627,7 +1629,7 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
       if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus11)
         break;
 
-      SourceLocation Loc = DiagInfo.getLocation();
+      SourceLocation Loc = Diags.getCurrentDiagLoc();
 
       // Suppress this diagnostic.
       ++NumSFINAEErrors;
@@ -1635,13 +1637,16 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
       // Make a copy of this suppressed diagnostic and store it with the
       // template-deduction information.
       if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
+        Diagnostic DiagInfo(&Diags);
         (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
                        PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
       }
 
       Diags.setLastDiagnosticIgnored(true);
+      Diags.Clear();
 
-      // Now produce a C++98 compatibility warning.
+      // Now the diagnostic state is clear, produce a C++98 compatibility
+      // warning.
       Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
 
       // The last diagnostic which Sema produced was ignored. Suppress any
@@ -1654,12 +1659,14 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
       // Make a copy of this suppressed diagnostic and store it with the
       // template-deduction information;
       if (*Info) {
+        Diagnostic DiagInfo(&Diags);
         (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(),
                        PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
       }
 
       // Suppress this diagnostic.
       Diags.setLastDiagnosticIgnored(true);
+      Diags.Clear();
       return;
     }
   }
@@ -1669,7 +1676,7 @@ void Sema::EmitDiagnostic(unsigned DiagID, const DiagnosticBuilder &DB) {
   Context.setPrintingPolicy(getPrintingPolicy());
 
   // Emit the diagnostic.
-  if (!Diags.EmitDiagnostic(DB))
+  if (!Diags.EmitCurrentDiagnostic())
     return;
 
   // If this is not a note, and we're in a template instantiation