Variadic templates: extend the Expr class with a bit that specifies

whether the expression contains an unexpanded parameter pack, in the
same vein as the changes to the Type hierarchy. Compute this bit
within all of the Expr subclasses.

This change required a bunch of reshuffling of dependency
calculations, mainly to consolidate them inside the constructors and
to fuse multiple loops that iterate over arguments to determine type
dependence, value dependence, and (now) containment of unexpanded
parameter packs.

Again, testing is painfully sparse, because all of the diagnostics
will change and it is more important to test the to-be-written visitor
that collects unexpanded parameter packs.

llvm-svn: 121831

5 files changed, 12 insertions, 21 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 218a0b313d2..baa7bf86707 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2149,10 +2149,8 @@ Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS,
   // we've picked a target.
   R.suppressDiagnostics();
 
-  bool Dependent
-    = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0);
   UnresolvedLookupExpr *ULE
-    = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(),
+    = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
                                    (NestedNameSpecifier*) SS.getScopeRep(),
                                    SS.getRange(), R.getLookupNameInfo(),
                                    NeedsADL, R.isOverloadedResult(),
@@ -3324,18 +3322,12 @@ Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
   // Construct an unresolved result if we in fact got an unresolved
   // result.
   if (R.isOverloadedResult() || R.isUnresolvableResult()) {
-    bool Dependent =
-      BaseExprType->isDependentType() ||
-      R.isUnresolvableResult() ||
-      OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs);
-
     // Suppress any lookup-related diagnostics; we'll do these when we
     // pick a member.
     R.suppressDiagnostics();
 
     UnresolvedMemberExpr *MemExpr
-      = UnresolvedMemberExpr::Create(Context, Dependent,
-                                     R.isUnresolvableResult(),
+      = UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(),
                                      BaseExpr, BaseExprType,
                                      IsArrow, OpLoc,
                                      Qualifier, SS.getRange(),
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 76fcaeae58d..9dcf9003dc0 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -3633,7 +3633,8 @@ void Sema::IgnoredValueConversions(Expr *&E) {
 }
 
 ExprResult Sema::ActOnFinishFullExpr(Expr *FullExpr) {
-  if (!FullExpr) return ExprError();
+  if (!FullExpr) 
+    return ExprError();
 
   if (DiagnoseUnexpandedParameterPack(FullExpr))
     return ExprError();
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 569be266776..5a2150664ca 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -7275,7 +7275,7 @@ Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn,
     
     CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
     UnresolvedLookupExpr *Fn
-      = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
+      = UnresolvedLookupExpr::Create(Context, NamingClass,
                                      0, SourceRange(), OpNameInfo,
                                      /*ADL*/ true, IsOverloaded(Fns),
                                      Fns.begin(), Fns.end());
@@ -7452,9 +7452,8 @@ Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
     // TODO: provide better source location info in DNLoc component.
     DeclarationNameInfo OpNameInfo(OpName, OpLoc);
     UnresolvedLookupExpr *Fn
-      = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
-                                     0, SourceRange(), OpNameInfo,
-                                     /*ADL*/ true, IsOverloaded(Fns),
+      = UnresolvedLookupExpr::Create(Context, NamingClass, 0, SourceRange(), 
+                                     OpNameInfo, /*ADL*/ true, IsOverloaded(Fns),
                                      Fns.begin(), Fns.end());
     return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
                                                    Args, 2,
@@ -7679,7 +7678,7 @@ Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
     DeclarationNameInfo OpNameInfo(OpName, LLoc);
     OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
     UnresolvedLookupExpr *Fn
-      = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
+      = UnresolvedLookupExpr::Create(Context, NamingClass,
                                      0, SourceRange(), OpNameInfo,
                                      /*ADL*/ true, /*Overloaded*/ false,
                                      UnresolvedSetIterator(),
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 6c212a7eb82..2c7ff5bd47b 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -32,7 +32,9 @@ using namespace sema;
 
 StmtResult Sema::ActOnExprStmt(FullExprArg expr) {
   Expr *E = expr.get();
-  assert(E && "ActOnExprStmt(): missing expression");
+  if (!E) // FIXME: FullExprArg has no error state?
+    return StmtError();
+
   // C99 6.8.3p2: The expression in an expression statement is evaluated as a
   // void expression for its side effects.  Conversion to void allows any
   // operand, even incomplete types.
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 141c41618d8..d38bffd9e36 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -1709,11 +1709,8 @@ ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
   // We don't want lookup warnings at this point.
   R.suppressDiagnostics();
   
-  bool Dependent
-    = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(),
-                                              &TemplateArgs);
   UnresolvedLookupExpr *ULE
-    = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(),
+    = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
                                    Qualifier, QualifierRange,
                                    R.getLookupNameInfo(),
                                    RequiresADL, TemplateArgs,