Add a convenience interface for checking expression arguments to unary

traits which uses the information embedded in the expression. Use this
to simplify several interfaces which repeated information embedded in
the expression through explicit arguments. I added an assertion that the
only extra piece of data to come in from the parser matches what is
stored in the expression. No functionality change intended here.

Also cleaned up the doxygen comments for some of these methods and some
formatting oddities.

llvm-svn: 132115

1 files changed, 48 insertions, 25 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ce929d58ee4..33f4780799e 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -3054,8 +3054,34 @@ ExprResult Sema::ActOnParenExpr(SourceLocation L,
   return Owned(new (Context) ParenExpr(L, R, E));
 }
 
+/// \brief Check the constrains on expression operands to unary type expression
+/// and type traits.
+///
+/// This is just a convenience wrapper around
+/// Sema::CheckUnaryExprOrTypeTraitOperand.
+bool Sema::CheckUnaryExprOrTypeTraitOperand(Expr *Op,
+                                            UnaryExprOrTypeTrait ExprKind) {
+  return CheckUnaryExprOrTypeTraitOperand(Op->getType(),
+                                          Op->getExprLoc(),
+                                          Op->getSourceRange(),
+                                          ExprKind);
+}
+
+/// \brief Check the constraints on operands to unary expression and type
+/// traits.
+///
+/// This will complete any types necessary, and validate the various constraints
+/// on those operands.
+///
 /// The UsualUnaryConversions() function is *not* called by this routine.
-/// See C99 6.3.2.1p[2-4] for more details.
+/// C99 6.3.2.1p[2-4] all state:
+///   Except when it is the operand of the sizeof operator ...
+///
+/// C++ [expr.sizeof]p4
+///   The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
+///   standard conversions are not applied to the operand of sizeof.
+///
+/// This policy is followed for all of the unary trait expressions.
 bool Sema::CheckUnaryExprOrTypeTraitOperand(QualType exprType,
                                             SourceLocation OpLoc,
                                             SourceRange ExprRange,
@@ -3117,8 +3143,7 @@ bool Sema::CheckUnaryExprOrTypeTraitOperand(QualType exprType,
   return false;
 }
 
-static bool CheckAlignOfExpr(Sema &S, Expr *E, SourceLocation OpLoc,
-                             SourceRange ExprRange) {
+static bool CheckAlignOfExpr(Sema &S, Expr *E) {
   E = E->IgnoreParens();
 
   // alignof decl is always ok.
@@ -3130,7 +3155,8 @@ static bool CheckAlignOfExpr(Sema &S, Expr *E, SourceLocation OpLoc,
     return false;
 
   if (E->getBitField()) {
-   S. Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange;
+    S.Diag(E->getExprLoc(), diag::err_sizeof_alignof_bitfield)
+       << 1 << E->getSourceRange();
     return true;
   }
 
@@ -3140,20 +3166,17 @@ static bool CheckAlignOfExpr(Sema &S, Expr *E, SourceLocation OpLoc,
     if (isa<FieldDecl>(ME->getMemberDecl()))
       return false;
 
-  return S.CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, ExprRange,
-                                            UETT_AlignOf);
+  return S.CheckUnaryExprOrTypeTraitOperand(E, UETT_AlignOf);
 }
 
-bool Sema::CheckVecStepExpr(Expr *E, SourceLocation OpLoc,
-                            SourceRange ExprRange) {
+bool Sema::CheckVecStepExpr(Expr *E) {
   E = E->IgnoreParens();
 
   // Cannot know anything else if the expression is dependent.
   if (E->isTypeDependent())
     return false;
 
-  return CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, ExprRange,
-                                          UETT_VecStep);
+  return CheckUnaryExprOrTypeTraitOperand(E, UETT_VecStep);
 }
 
 /// \brief Build a sizeof or alignof expression given a type operand.
@@ -3180,36 +3203,33 @@ Sema::CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo,
 /// \brief Build a sizeof or alignof expression given an expression
 /// operand.
 ExprResult
-Sema::CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc,
-                                     UnaryExprOrTypeTrait ExprKind,
-                                     SourceRange R) {
+Sema::CreateUnaryExprOrTypeTraitExpr(Expr *E, UnaryExprOrTypeTrait ExprKind) {
   // Verify that the operand is valid.
   bool isInvalid = false;
   if (E->isTypeDependent()) {
     // Delay type-checking for type-dependent expressions.
   } else if (ExprKind == UETT_AlignOf) {
-    isInvalid = CheckAlignOfExpr(*this, E, OpLoc, R);
+    isInvalid = CheckAlignOfExpr(*this, E);
   } else if (ExprKind == UETT_VecStep) {
-    isInvalid = CheckVecStepExpr(E, OpLoc, R);
+    isInvalid = CheckVecStepExpr(E);
   } else if (E->getBitField()) {  // C99 6.5.3.4p1.
-    Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0;
+    Diag(E->getExprLoc(), diag::err_sizeof_alignof_bitfield) << 0;
     isInvalid = true;
   } else if (E->getType()->isPlaceholderType()) {
     ExprResult PE = CheckPlaceholderExpr(E);
     if (PE.isInvalid()) return ExprError();
-    return CreateUnaryExprOrTypeTraitExpr(PE.take(), OpLoc, ExprKind, R);
+    return CreateUnaryExprOrTypeTraitExpr(PE.take(), ExprKind);
   } else {
-    isInvalid = CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, R,
-                                                 UETT_SizeOf);
+    isInvalid = CheckUnaryExprOrTypeTraitOperand(E, UETT_SizeOf);
   }
 
   if (isInvalid)
     return ExprError();
 
   // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t.
-  return Owned(new (Context) UnaryExprOrTypeTraitExpr(ExprKind, E,
-                                                      Context.getSizeType(),
-                                                      OpLoc, R.getEnd()));
+  return Owned(new (Context) UnaryExprOrTypeTraitExpr(
+      ExprKind, E, Context.getSizeType(), E->getExprLoc(),
+      E->getSourceRange().getEnd()));
 }
 
 /// ActOnUnaryExprOrTypeTraitExpr - Handle @c sizeof(type) and @c sizeof @c
@@ -3229,9 +3249,12 @@ Sema::ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc,
   }
 
   Expr *ArgEx = (Expr *)TyOrEx;
-  ExprResult Result
-    = CreateUnaryExprOrTypeTraitExpr(ArgEx, OpLoc, ExprKind,
-                                     ArgEx->getSourceRange());
+
+  // Make sure the location is accurately represented in the Expr node.
+  // FIXME: Is this really needed?
+  assert(ArgEx->getExprLoc() != OpLoc && "Mismatched locations");
+
+  ExprResult Result = CreateUnaryExprOrTypeTraitExpr(ArgEx, ExprKind);
 
   return move(Result);
 }