From: Eli Friedman Date: Wed, 4 Mar 2009 05:52:32 +0000 (+0000) Subject: Minor cleanup for choose expressions: add a helper that returns the X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7976932a1c256d447316ffac58e9821417725e34;p=clang Minor cleanup for choose expressions: add a helper that returns the chosen sub-expression, rather than just evaluating the condition. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66018 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h index e7c9702852..48c2ad0cef 100644 --- a/include/clang/AST/Expr.h +++ b/include/clang/AST/Expr.h @@ -1493,9 +1493,12 @@ public: /// ChooseExpr - GNU builtin-in function __builtin_choose_expr. /// This AST node is similar to the conditional operator (?:) in C, with /// the following exceptions: -/// - the test expression must be a constant expression. -/// - the expression returned has it's type unaltered by promotion rules. -/// - does not evaluate the expression that was not chosen. +/// - the test expression must be a integer constant expression. +/// - the expression returned acts like the chosen subexpression in every +/// visible way: the type is the same as that of the chosen subexpression, +/// and all predicates (whether it's an l-value, whether it's an integer +/// constant expression, etc.) return the same result as for the chosen +/// sub-expression. class ChooseExpr : public Expr { enum { COND, LHS, RHS, END_EXPR }; Stmt* SubExprs[END_EXPR]; // Left/Middle/Right hand sides. @@ -1509,11 +1512,17 @@ public: SubExprs[LHS] = lhs; SubExprs[RHS] = rhs; } - - /// isConditionTrue - Return true if the condition is true. This is always - /// statically knowable for a well-formed choosexpr. + + /// isConditionTrue - Return whether the condition is true (i.e. not + /// equal to zero). bool isConditionTrue(ASTContext &C) const; - + + /// getChosenSubExpr - Return the subexpression chosen according to the + /// condition. + Expr *getChosenSubExpr(ASTContext &C) const { + return isConditionTrue(C) ? getLHS() : getRHS(); + } + Expr *getCond() const { return cast(SubExprs[COND]); } Expr *getLHS() const { return cast(SubExprs[LHS]); } Expr *getRHS() const { return cast(SubExprs[RHS]); } diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index d0d14f2b7a..38bcc9bf31 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -603,11 +603,7 @@ Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const { return LV_Valid; case ChooseExprClass: // __builtin_choose_expr is an lvalue if the selected operand is. - if (cast(this)->isConditionTrue(Ctx)) - return cast(this)->getLHS()->isLvalue(Ctx); - else - return cast(this)->getRHS()->isLvalue(Ctx); - + return cast(this)->getChosenSubExpr(Ctx)->isLvalue(Ctx); case ExtVectorElementExprClass: if (cast(this)->containsDuplicateElements()) return LV_DuplicateVectorComponents; @@ -1110,9 +1106,7 @@ static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) { case Expr::CXXDefaultArgExprClass: return CheckICE(cast(E)->getExpr(), Ctx); case Expr::ChooseExprClass: { - const ChooseExpr *CE = cast(E); - Expr *SubExpr = CE->isConditionTrue(Ctx) ? CE->getLHS() : CE->getRHS(); - return CheckICE(SubExpr, Ctx); + return CheckICE(cast(E)->getChosenSubExpr(Ctx), Ctx); } } } diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp index 86a7e8217f..6fb2abe7cd 100644 --- a/lib/AST/ExprConstant.cpp +++ b/lib/AST/ExprConstant.cpp @@ -389,10 +389,8 @@ APValue PointerExprEvaluator::VisitConditionalOperator(ConditionalOperator *E) { } APValue PointerExprEvaluator::VisitChooseExpr(ChooseExpr *E) { - Expr* EvalExpr = E->isConditionTrue(Info.Ctx) ? E->getLHS() : E->getRHS(); - APValue Result; - if (EvaluatePointer(EvalExpr, Result, Info)) + if (EvaluatePointer(E->getChosenSubExpr(Info.Ctx), Result, Info)) return Result; return APValue(); } @@ -522,10 +520,8 @@ APValue VectorExprEvaluator::VisitConditionalOperator(const ConditionalOperator } APValue VectorExprEvaluator::VisitChooseExpr(const ChooseExpr *E) { - Expr* EvalExpr = E->isConditionTrue(Info.Ctx) ? E->getLHS() : E->getRHS(); - APValue Result; - if (EvaluateVector(EvalExpr, Result, Info)) + if (EvaluateVector(E->getChosenSubExpr(Info.Ctx), Result, Info)) return Result; return APValue(); } @@ -1185,9 +1181,7 @@ bool IntExprEvaluator::VisitCastExpr(CastExpr *E) { } bool IntExprEvaluator::VisitChooseExpr(const ChooseExpr *E) { - Expr* EvalExpr = E->isConditionTrue(Info.Ctx) ? E->getLHS() : E->getRHS(); - - return Visit(EvalExpr); + return Visit(E->getChosenSubExpr(Info.Ctx)); } bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) { diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp index d54c6954fb..3ab8568675 100644 --- a/lib/CodeGen/CGExpr.cpp +++ b/lib/CodeGen/CGExpr.cpp @@ -178,11 +178,7 @@ LValue CodeGenFunction::EmitLValue(const Expr *E) { case Expr::CompoundLiteralExprClass: return EmitCompoundLiteralLValue(cast(E)); case Expr::ChooseExprClass: - // __builtin_choose_expr is the lvalue of the selected operand. - if (cast(E)->isConditionTrue(getContext())) - return EmitLValue(cast(E)->getLHS()); - else - return EmitLValue(cast(E)->getRHS()); + return EmitLValue(cast(E)->getChosenSubExpr(getContext())); } } diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp index c676b579e6..e970ba2561 100644 --- a/lib/CodeGen/CGExprComplex.cpp +++ b/lib/CodeGen/CGExprComplex.cpp @@ -509,8 +509,7 @@ VisitConditionalOperator(const ConditionalOperator *E) { } ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) { - // Emit the LHS or RHS as appropriate. - return Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() :E->getRHS()); + return Visit(E->getChosenSubExpr(CGF.getContext())); } ComplexPairTy ComplexExprEmitter::VisitInitListExpr(InitListExpr *E) { diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp index 38cc3eec5d..9951d8794b 100644 --- a/lib/CodeGen/CGExprScalar.cpp +++ b/lib/CodeGen/CGExprScalar.cpp @@ -1307,9 +1307,7 @@ VisitConditionalOperator(const ConditionalOperator *E) { } Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { - // Emit the LHS or RHS as appropriate. - return - Visit(E->isConditionTrue(CGF.getContext()) ? E->getLHS() : E->getRHS()); + return Visit(E->getChosenSubExpr(CGF.getContext())); } Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {