diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp index ca478707ef8f..999788f58c34 100644 --- a/clang/lib/CodeGen/CodeGenFunction.cpp +++ b/clang/lib/CodeGen/CodeGenFunction.cpp @@ -387,9 +387,12 @@ bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) { // If this is a label, we have to emit the code, consider something like: // if (0) { ... foo: bar(); } goto foo; + // + // TODO: If anyone cared, we could track __label__'s, since we know that you + // can't jump to one from outside their declared region. if (isa(S)) return true; - + // If this is a case/default statement, and we haven't seen a switch, we have // to emit the code. if (isa(S) && !IgnoreCaseStmts) @@ -407,27 +410,62 @@ bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) { return false; } +/// containsBreak - Return true if the statement contains a break out of it. +/// If the statement (recursively) contains a switch or loop with a break +/// inside of it, this is fine. +bool CodeGenFunction::containsBreak(const Stmt *S) { + // Null statement, not a label! + if (S == 0) return false; + + // If this is a switch or loop that defines its own break scope, then we can + // include it and anything inside of it. + if (isa(S) || isa(S) || isa(S) || + isa(S)) + return true; + + // Scan subexpressions for verboten breaks. + for (Stmt::const_child_range I = S->children(); I; ++I) + if (containsBreak(*I)) + return true; + + return false; +} + /// ConstantFoldsToSimpleInteger - If the specified expression does not fold /// to a constant, or if it does but contains a label, return false. If it /// constant folds return true and set the boolean result in Result. bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond, bool &ResultBool) { + llvm::APInt ResultInt; + if (!ConstantFoldsToSimpleInteger(Cond, ResultInt)) + return false; + + ResultBool = ResultInt.getBoolValue(); + return true; +} + +/// ConstantFoldsToSimpleInteger - If the specified expression does not fold +/// to a constant, or if it does but contains a label, return false. If it +/// constant folds return true and set the folded value. +bool CodeGenFunction:: +ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APInt &ResultInt) { // FIXME: Rename and handle conversion of other evaluatable things // to bool. Expr::EvalResult Result; if (!Cond->Evaluate(Result, getContext()) || !Result.Val.isInt() || Result.HasSideEffects) return false; // Not foldable, not integer or not fully evaluatable. - + if (CodeGenFunction::ContainsLabel(Cond)) return false; // Contains a label. - - ResultBool = Result.Val.getInt().getBoolValue(); + + ResultInt = Result.Val.getInt(); return true; } + /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if /// statement) to the specified blocks. Based on the condition, this might try /// to simplify the codegen of the conditional based on the branch. diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h index 7a94b92fbbe7..0edd0f01281c 100644 --- a/clang/lib/CodeGen/CodeGenFunction.h +++ b/clang/lib/CodeGen/CodeGenFunction.h @@ -2044,11 +2044,21 @@ public: /// that we can just remove the code. static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false); + /// containsBreak - Return true if the statement contains a break out of it. + /// If the statement (recursively) contains a switch or loop with a break + /// inside of it, this is fine. + static bool containsBreak(const Stmt *S); + /// ConstantFoldsToSimpleInteger - If the specified expression does not fold /// to a constant, or if it does but contains a label, return false. If it /// constant folds return true and set the boolean result in Result. bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result); + /// ConstantFoldsToSimpleInteger - If the specified expression does not fold + /// to a constant, or if it does but contains a label, return false. If it + /// constant folds return true and set the folded value. + bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APInt &Result); + /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an /// if statement) to the specified blocks. Based on the condition, this might /// try to simplify the codegen of the conditional based on the branch.