From 8a50733034edd6a349b34e2b9f0c8d0a874846d3 Mon Sep 17 00:00:00 2001
From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Fri, 2 Jul 2010 23:30:15 +0000
Subject: [PATCH] Fix broken PCH support for CXXDefaultArgExpr.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107541 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/ExprCXX.h    | 13 +++----------
 lib/Frontend/PCHReaderStmt.cpp | 19 +++++++++++++------
 lib/Frontend/PCHWriterStmt.cpp | 13 +++++++------
 3 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/include/clang/AST/ExprCXX.h b/include/clang/AST/ExprCXX.h
index 4514f96f08..6da32bacd3 100644
--- a/include/clang/AST/ExprCXX.h
+++ b/include/clang/AST/ExprCXX.h
@@ -465,7 +465,6 @@ class CXXDefaultArgExpr : public Expr {
   /// \brief The location where the default argument expression was used.
   SourceLocation Loc;
   
-protected:
   CXXDefaultArgExpr(StmtClass SC, SourceLocation Loc, ParmVarDecl *param)
     : Expr(SC, 
            param->hasUnparsedDefaultArg()
@@ -504,9 +503,6 @@ public:
   // Retrieve the parameter that the argument was created from.
   const ParmVarDecl *getParam() const { return Param.getPointer(); }
   ParmVarDecl *getParam() { return Param.getPointer(); }
-
-  /// isExprStored - Return true if this expression owns the expression.
-  bool isExprStored() const { return Param.getInt(); }
   
   // Retrieve the actual argument to the function call.
   const Expr *getExpr() const { 
@@ -519,16 +515,10 @@ public:
       return *reinterpret_cast<Expr **> (this + 1);
     return getParam()->getDefaultArg(); 
   }
-  
-  void setExpr(Expr *E) {
-    Param.setInt(true);
-    Param.setPointer((ParmVarDecl*)E);
-  }
 
   /// \brief Retrieve the location where this default argument was actually 
   /// used.
   SourceLocation getUsedLocation() const { return Loc; }
-  void setUsedLocation(SourceLocation L) { Loc = L; }
   
   virtual SourceRange getSourceRange() const {
     // Default argument expressions have no representation in the
@@ -544,6 +534,9 @@ public:
   // Iterators
   virtual child_iterator child_begin();
   virtual child_iterator child_end();
+
+  friend class PCHStmtReader;
+  friend class PCHStmtWriter;
 };
 
 /// CXXTemporary - Represents a C++ temporary.
diff --git a/lib/Frontend/PCHReaderStmt.cpp b/lib/Frontend/PCHReaderStmt.cpp
index b9751e8496..c2dea3adc2 100644
--- a/lib/Frontend/PCHReaderStmt.cpp
+++ b/lib/Frontend/PCHReaderStmt.cpp
@@ -982,10 +982,11 @@ void PCHStmtReader::VisitCXXThrowExpr(CXXThrowExpr *E) {
 
 void PCHStmtReader::VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
   VisitExpr(E);
-  E->setUsedLocation(SourceLocation::getFromRawEncoding(Record[Idx++]));
-  bool HasStoredExpr = Record[Idx++];
-  if (!HasStoredExpr) return;
-  E->setExpr(Reader.ReadSubExpr());
+
+  assert(Record[Idx] == E->Param.getInt() && "We messed up at creation ?");
+  ++Idx; // HasOtherExprStored and SubExpr was handled during creation.
+  E->Param.setPointer(cast<ParmVarDecl>(Reader.GetDecl(Record[Idx++])));
+  E->Loc = Reader.ReadSourceLocation(Record, Idx);
 }
 
 void PCHStmtReader::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
@@ -1552,9 +1553,15 @@ Stmt *PCHReader::ReadStmtFromStream(llvm::BitstreamCursor &Cursor) {
     case pch::EXPR_CXX_THROW:
       S = new (Context) CXXThrowExpr(Empty);
       break;
-    case pch::EXPR_CXX_DEFAULT_ARG:
-      S = new (Context) CXXDefaultArgExpr(Empty);
+    case pch::EXPR_CXX_DEFAULT_ARG: {
+      bool HasOtherExprStored = Record[PCHStmtReader::NumExprFields];
+      if (HasOtherExprStored) {
+        Expr *SubExpr = ReadSubExpr();
+        S = CXXDefaultArgExpr::Create(*Context, SourceLocation(), 0, SubExpr);
+      } else
+        S = new (Context) CXXDefaultArgExpr(Empty);
       break;
+    }
     case pch::EXPR_CXX_BIND_TEMPORARY:
       S = new (Context) CXXBindTemporaryExpr(Empty);
       break;
diff --git a/lib/Frontend/PCHWriterStmt.cpp b/lib/Frontend/PCHWriterStmt.cpp
index 11b1afd373..12fcde845e 100644
--- a/lib/Frontend/PCHWriterStmt.cpp
+++ b/lib/Frontend/PCHWriterStmt.cpp
@@ -983,13 +983,14 @@ void PCHStmtWriter::VisitCXXThrowExpr(CXXThrowExpr *E) {
 
 void PCHStmtWriter::VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
   VisitExpr(E);
-  Writer.AddSourceLocation(E->getUsedLocation(), Record);
-  if (E->isExprStored()) {
-    Record.push_back(1);
+
+  bool HasOtherExprStored = E->Param.getInt();
+  // Store these first, the reader reads them before creation.
+  Record.push_back(HasOtherExprStored);
+  if (HasOtherExprStored)
     Writer.AddStmt(E->getExpr());
-  } else {
-    Record.push_back(0);
-  }
+  Writer.AddDeclRef(E->getParam(), Record);
+  Writer.AddSourceLocation(E->getUsedLocation(), Record);
 
   Code = pch::EXPR_CXX_DEFAULT_ARG;
 }
-- 
2.40.0