Rework our handling of temporary objects within the conditions of

if/switch/while/do/for statements. Previously, we would end up either:

  (1) Forgetting to destroy temporaries created in the condition (!),
  (2) Destroying the temporaries created in the condition *before*
  converting the condition to a boolean value (or, in the case of a
  switch statement, to an integral or enumeral value), or
  (3) In a for statement, destroying the condition's temporaries at
  the end of the increment expression (!).

We now destroy temporaries in conditions at the right times. This
required some tweaking of the Parse/Sema interaction, since the parser
was building full expressions too early in many places.

Fixes PR7067.





git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103187 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 1 deletions

diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 9eb9506239..b7ccea53d5 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -689,17 +689,33 @@ Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
 /// \param DeclResult if the condition was parsed as a declaration, the
 /// parsed declaration.
 ///
+/// \param Loc The location of the start of the statement that requires this
+/// condition, e.g., the "for" in a for loop.
+///
+/// \param ConvertToBoolean Whether the condition expression should be
+/// converted to a boolean value.
+///
 /// \returns true if there was a parsing, false otherwise.
 bool Parser::ParseCXXCondition(OwningExprResult &ExprResult,
-                               DeclPtrTy &DeclResult) {
+                               DeclPtrTy &DeclResult,
+                               SourceLocation Loc,
+                               bool ConvertToBoolean) {
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteOrdinaryName(CurScope, Action::CCC_Condition);
     ConsumeToken();
   }
 
   if (!isCXXConditionDeclaration()) {
+    // Parse the expression.
     ExprResult = ParseExpression(); // expression
     DeclResult = DeclPtrTy();
+    if (ExprResult.isInvalid())
+      return true;
+
+    // If required, convert to a boolean value.
+    if (ConvertToBoolean)
+      ExprResult
+        = Actions.ActOnBooleanCondition(CurScope, Loc, move(ExprResult));
     return ExprResult.isInvalid();
   }
 
@@ -747,6 +763,9 @@ bool Parser::ParseCXXCondition(OwningExprResult &ExprResult,
     Diag(Tok, diag::err_expected_equal_after_declarator);
   }
   
+  // FIXME: Build a reference to this declaration? Convert it to bool?
+  // (This is currently handled by Sema).
+  
   return false;
 }