Implement the GNU __null extension
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60235 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 7a8119c..3c021c2 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1031,8 +1031,11 @@
= dyn_cast<CXXDefaultArgExpr>(this)) {
// See through default argument expressions
return DefaultArg->getExpr()->isNullPointerConstant(Ctx);
+ } else if (isa<GNUNullExpr>(this)) {
+ // The GNU __null extension is always a null pointer constant.
+ return true;
}
-
+
// This expression must be an integer type.
if (!getType()->isIntegerType())
return false;
@@ -1383,6 +1386,10 @@
Stmt::child_iterator ChooseExpr::child_begin() { return &SubExprs[0]; }
Stmt::child_iterator ChooseExpr::child_end() { return &SubExprs[0]+END_EXPR; }
+// GNUNullExpr
+Stmt::child_iterator GNUNullExpr::child_begin() { return child_iterator(); }
+Stmt::child_iterator GNUNullExpr::child_end() { return child_iterator(); }
+
// OverloadExpr
Stmt::child_iterator OverloadExpr::child_begin() { return &SubExprs[0]; }
Stmt::child_iterator OverloadExpr::child_end() { return &SubExprs[0]+NumExprs; }
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index fcebdab..b6f0707 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -783,6 +783,10 @@
OS << ")";
}
+void StmtPrinter::VisitGNUNullExpr(GNUNullExpr *) {
+ OS << "__null";
+}
+
void StmtPrinter::VisitOverloadExpr(OverloadExpr *Node) {
OS << "__builtin_overload(";
for (unsigned i = 0, e = Node->getNumSubExprs(); i != e; ++i) {
diff --git a/lib/AST/StmtSerialization.cpp b/lib/AST/StmtSerialization.cpp
index 8bf7039..3cf1f54 100644
--- a/lib/AST/StmtSerialization.cpp
+++ b/lib/AST/StmtSerialization.cpp
@@ -61,6 +61,9 @@
case CharacterLiteralClass:
return CharacterLiteral::CreateImpl(D, C);
+ case ChooseExprClass:
+ return ChooseExpr::CreateImpl(D, C);
+
case CompoundAssignOperatorClass:
return CompoundAssignOperator::CreateImpl(D, C);
@@ -94,6 +97,9 @@
case ForStmtClass:
return ForStmt::CreateImpl(D, C);
+ case GNUNullExprClass:
+ return GNUNullExpr::CreateImpl(D, C);
+
case GotoStmtClass:
return GotoStmt::CreateImpl(D, C);
@@ -904,6 +910,17 @@
return CE;
}
+void GNUNullExpr::EmitImpl(llvm::Serializer &S) const {
+ S.Emit(getType());
+ S.Emit(TokenLoc);
+}
+
+GNUNullExpr *GNUNullExpr::CreateImpl(llvm::Deserializer &D, ASTContext &C) {
+ QualType T = QualType::ReadVal(D);
+ SourceLocation TL = SourceLocation::ReadVal(D);
+ return new GNUNullExpr(T, TL);
+}
+
void OverloadExpr::EmitImpl(llvm::Serializer& S) const {
S.Emit(getType());
S.Emit(BuiltinLoc);
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 66b1d18..df46612 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -378,6 +378,7 @@
/// [GNU] '__builtin_choose_expr' '(' assign-expr ',' assign-expr ','
/// assign-expr ')'
/// [GNU] '__builtin_types_compatible_p' '(' type-name ',' type-name ')'
+/// [GNU] '__null'
/// [OBJC] '[' objc-message-expr ']'
/// [OBJC] '@selector' '(' objc-selector-arg ')'
/// [OBJC] '@protocol' '(' identifier ')'
@@ -531,6 +532,9 @@
case tok::kw___builtin_overload:
case tok::kw___builtin_types_compatible_p:
return ParseBuiltinPrimaryExpression();
+ case tok::kw___null:
+ return Actions.ActOnGNUNullExpr(ConsumeToken());
+ break;
case tok::plusplus: // unary-expression: '++' unary-expression
case tok::minusminus: { // unary-expression: '--' unary-expression
SourceLocation SavedLoc = ConsumeToken();
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 57caa6e..044bfbd 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -736,6 +736,9 @@
ExprTy *expr, TypeTy *type,
SourceLocation RPLoc);
+ // __null
+ virtual ExprResult ActOnGNUNullExpr(SourceLocation TokenLoc);
+
//===------------------------- "Block" Extension ------------------------===//
/// ActOnBlockStart - This callback is invoked when a block literal is
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index e21047e..fb96469 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -3603,6 +3603,18 @@
return new VAArgExpr(BuiltinLoc, E, T.getNonReferenceType(), RPLoc);
}
+Sema::ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) {
+ // The type of __null will be int or long, depending on the size of
+ // pointers on the target.
+ QualType Ty;
+ if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth())
+ Ty = Context.IntTy;
+ else
+ Ty = Context.LongTy;
+
+ return new GNUNullExpr(Ty, TokenLoc);
+}
+
bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy,
SourceLocation Loc,
QualType DstType, QualType SrcType,