Use unique_ptr for cached tokens for default arguments in C++.

Summary:
This changes pointers to cached tokens for default arguments in C++ from raw pointers to unique_ptrs.  There was a fixme in the code where the cached tokens are created  about using a smart pointer.

The change is straightforward, though I did have to track down and fix a memory corruption caused by the change.  memcpy was being used to copy parameter information.  This duplicated the unique_ptr, which led to the cached token buffer being deleted prematurely.

Patch by David Tarditi!

Reviewers: malcolm.parsons

Subscribers: arphaman, malcolm.parsons, cfe-commits

Differential Revision: https://reviews.llvm.org/D26435

llvm-svn: 287241

1 files changed, 4 insertions, 6 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index d155432cbd2..9184f0145a2 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -6022,7 +6022,7 @@ void Parser::ParseParameterDeclarationClause(
 
     // DefArgToks is used when the parsing of default arguments needs
     // to be delayed.
-    CachedTokens *DefArgToks = nullptr;
+    std::unique_ptr<CachedTokens> DefArgToks;
 
     // If no parameter was specified, verify that *something* was specified,
     // otherwise we have a missing type and identifier.
@@ -6058,13 +6058,11 @@ void Parser::ParseParameterDeclarationClause(
           // If we're inside a class definition, cache the tokens
           // corresponding to the default argument. We'll actually parse
           // them when we see the end of the class definition.
-          // FIXME: Can we use a smart pointer for Toks?
-          DefArgToks = new CachedTokens;
+          DefArgToks.reset(new CachedTokens);
 
           SourceLocation ArgStartLoc = NextToken().getLocation();
           if (!ConsumeAndStoreInitializer(*DefArgToks, CIK_DefaultArgument)) {
-            delete DefArgToks;
-            DefArgToks = nullptr;
+            DefArgToks.reset();
             Actions.ActOnParamDefaultArgumentError(Param, EqualLoc);
           } else {
             Actions.ActOnParamUnparsedDefaultArgument(Param, EqualLoc,
@@ -6100,7 +6098,7 @@ void Parser::ParseParameterDeclarationClause(
 
       ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
                                           ParmDeclarator.getIdentifierLoc(), 
-                                          Param, DefArgToks));
+                                          Param, std::move(DefArgToks)));
     }
 
     if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) {