From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 27 Jun 2013 21:43:17 +0000 (+0000)
Subject: Remove bogus VarDecl::extendsLifetimeOfTemporary function and inline it into
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=49bab4c0046e8300c79e79b7ca9a479696c7e87a;p=clang

Remove bogus VarDecl::extendsLifetimeOfTemporary function and inline it into
its only caller with a FIXME explaining why it's bogus.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185109 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 2eaf8d3a7f..8342f79f4e 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -1019,20 +1019,6 @@ public:
 
   void setInit(Expr *I);
 
-  /// \brief Determine whether this variable is a reference that
-  /// extends the lifetime of its temporary initializer.
-  ///
-  /// A reference extends the lifetime of its temporary initializer if
-  /// it's initializer is an rvalue that would normally go out of scope
-  /// at the end of the initializer (a full expression). In such cases,
-  /// the reference itself takes ownership of the temporary, which will
-  /// be destroyed when the reference goes out of scope. For example:
-  ///
-  /// \code
-  /// const int &r = 1.0; // creates a temporary of type 'int'
-  /// \endcode
-  bool extendsLifetimeOfTemporary() const;
-
   /// \brief Determine whether this variable's value can be used in a
   /// constant expression, according to the relevant language standard.
   /// This only checks properties of the declaration, and does not check
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index adba897bb5..5267789643 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1928,19 +1928,6 @@ bool VarDecl::checkInitIsICE() const {
   return Eval->IsICE;
 }
 
-bool VarDecl::extendsLifetimeOfTemporary() const {
-  assert(getType()->isReferenceType() &&"Non-references never extend lifetime");
-  
-  const Expr *E = getInit();
-  if (!E)
-    return false;
-  
-  if (const ExprWithCleanups *Cleanups = dyn_cast<ExprWithCleanups>(E))
-    E = Cleanups->getSubExpr();
-  
-  return isa<MaterializeTemporaryExpr>(E);
-}
-
 VarDecl *VarDecl::getInstantiatedFromStaticDataMember() const {
   if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo())
     return cast<VarDecl>(MSI->getInstantiatedFrom());
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 14b8fd4a10..695440c9cb 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -974,10 +974,23 @@ LocalScope* CFGBuilder::addLocalScopeForVarDecl(VarDecl *VD,
   // Check for const references bound to temporary. Set type to pointee.
   QualType QT = VD->getType();
   if (QT.getTypePtr()->isReferenceType()) {
-    if (!VD->extendsLifetimeOfTemporary())
+    // Attempt to determine whether this declaration lifetime-extends a
+    // temporary.
+    //
+    // FIXME: This is incorrect. Non-reference declarations can lifetime-extend
+    // temporaries, and a single declaration can extend multiple temporaries.
+    // We should look at the storage duration on each nested
+    // MaterializeTemporaryExpr instead.
+    const Expr *Init = VD->getInit();
+    if (!Init)
+      return Scope;
+    if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Init))
+      Init = EWC->getSubExpr();
+    if (!isa<MaterializeTemporaryExpr>(Init))
       return Scope;
 
-    QT = getReferenceInitTemporaryType(*Context, VD->getInit());
+    // Lifetime-extending a temporary.
+    QT = getReferenceInitTemporaryType(*Context, Init);
   }
 
   // Check for constant size array. Set type to array element type.