Reland r219810 "Fix late template parsing leak with incremental processing"

Original message:
Add a second late template parser callback meant to cleanup any
resources allocated by late template parsing.  Call it from the
Sema::ActOnEndOfTranslationUnit method after all pending template
instantiations have been completed.  Teach Parser::ParseTopLevelDecl to
install the cleanup callback when incremental processing is enabled so
that Parser::TemplateIds can be freed.

Patch by Brad King!

llvm-svn: 220400

1 files changed, 11 insertions, 1 deletions

diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index 27a852e9ff2..93e893e723b 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -510,6 +510,13 @@ namespace {
   };
 }
 
+void Parser::LateTemplateParserCleanupCallback(void *P) {
+  // While this RAII helper doesn't bracket any actual work, the destructor will
+  // clean up annotations that were created during ActOnEndOfTranslationUnit
+  // when incremental processing is enabled.
+  DestroyTemplateIdAnnotationsRAIIObj CleanupRAII(((Parser *)P)->TemplateIds);
+}
+
 /// ParseTopLevelDecl - Parse one top-level declaration, return whatever the
 /// action tells us to.  This returns true if the EOF was encountered.
 bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) {
@@ -542,7 +549,10 @@ bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) {
   case tok::eof:
     // Late template parsing can begin.
     if (getLangOpts().DelayedTemplateParsing)
-      Actions.SetLateTemplateParser(LateTemplateParserCallback, this);
+      Actions.SetLateTemplateParser(LateTemplateParserCallback,
+                                    PP.isIncrementalProcessingEnabled() ?
+                                    LateTemplateParserCleanupCallback : nullptr,
+                                    this);
     if (!PP.isIncrementalProcessingEnabled())
       Actions.ActOnEndOfTranslationUnit();
     //else don't tell Sema that we ended parsing: more input might come.