[cfe-commits] r134548 - in /cfe/trunk: include/clang/AST/ExprCXX.h include/clang/Parse/Parser.h include/clang/Sema/Scope.h include/clang/Sema/Sema.h lib/Parse/ParseExprCXX.cpp lib/Parse/ParseStmt.cpp lib/Sema/SemaExprCXX.cpp lib/Sema/SemaStmt.cpp lib/Sema/TreeTransform.h lib/Serialization/ASTReaderStmt.cpp lib/Serialization/ASTWriterStmt.cpp test/CXX/special/class.copy/p33-0x.cpp
Douglas Gregor
dgregor at apple.com
Wed Jul 6 15:04:07 PDT 2011
Author: dgregor
Date: Wed Jul 6 17:04:06 2011
New Revision: 134548
URL: http://llvm.org/viewvc/llvm-project?rev=134548&view=rev
Log:
Properly implement the scope restriction on the NRVO for
throw-expressions, such that we don't consider the NRVO when the
non-volatile automatic object comes from outside the innermost try
scope (C++0x [class.copymove]p13). In C++98/03, our ASTs were
incorrect but it didn't matter because IR generation doesn't actually
apply the NRVO here. In C++0x, however, we were moving from an object
when in fact we should have copied from it. Fixes PR10142 /
<rdar://problem/9714312>.
Modified:
cfe/trunk/include/clang/AST/ExprCXX.h
cfe/trunk/include/clang/Parse/Parser.h
cfe/trunk/include/clang/Sema/Scope.h
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Parse/ParseExprCXX.cpp
cfe/trunk/lib/Parse/ParseStmt.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaStmt.cpp
cfe/trunk/lib/Sema/TreeTransform.h
cfe/trunk/lib/Serialization/ASTReaderStmt.cpp
cfe/trunk/lib/Serialization/ASTWriterStmt.cpp
cfe/trunk/test/CXX/special/class.copy/p33-0x.cpp
Modified: cfe/trunk/include/clang/AST/ExprCXX.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/ExprCXX.h?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/ExprCXX.h (original)
+++ cfe/trunk/include/clang/AST/ExprCXX.h Wed Jul 6 17:04:06 2011
@@ -586,24 +586,35 @@
class CXXThrowExpr : public Expr {
Stmt *Op;
SourceLocation ThrowLoc;
+ /// \brief Whether the thrown variable (if any) is in scope.
+ unsigned IsThrownVariableInScope : 1;
+
+ friend class ASTStmtReader;
+
public:
// Ty is the void type which is used as the result type of the
// exepression. The l is the location of the throw keyword. expr
// can by null, if the optional expression to throw isn't present.
- CXXThrowExpr(Expr *expr, QualType Ty, SourceLocation l) :
+ CXXThrowExpr(Expr *expr, QualType Ty, SourceLocation l,
+ bool IsThrownVariableInScope) :
Expr(CXXThrowExprClass, Ty, VK_RValue, OK_Ordinary, false, false,
expr && expr->isInstantiationDependent(),
expr && expr->containsUnexpandedParameterPack()),
- Op(expr), ThrowLoc(l) {}
+ Op(expr), ThrowLoc(l), IsThrownVariableInScope(IsThrownVariableInScope) {}
CXXThrowExpr(EmptyShell Empty) : Expr(CXXThrowExprClass, Empty) {}
const Expr *getSubExpr() const { return cast_or_null<Expr>(Op); }
Expr *getSubExpr() { return cast_or_null<Expr>(Op); }
- void setSubExpr(Expr *E) { Op = E; }
SourceLocation getThrowLoc() const { return ThrowLoc; }
- void setThrowLoc(SourceLocation L) { ThrowLoc = L; }
+ /// \brief Determines whether the variable thrown by this expression (if any!)
+ /// is within the innermost try block.
+ ///
+ /// This information is required to determine whether the NRVO can apply to
+ /// this variable.
+ bool isThrownVariableInScope() const { return IsThrownVariableInScope; }
+
SourceRange getSourceRange() const {
if (getSubExpr() == 0)
return SourceRange(ThrowLoc, ThrowLoc);
Modified: cfe/trunk/include/clang/Parse/Parser.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Parse/Parser.h?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/include/clang/Parse/Parser.h (original)
+++ cfe/trunk/include/clang/Parse/Parser.h Wed Jul 6 17:04:06 2011
@@ -1314,6 +1314,9 @@
StmtResult ParseDefaultStatement(ParsedAttributes &Attr);
StmtResult ParseCompoundStatement(ParsedAttributes &Attr,
bool isStmtExpr = false);
+ StmtResult ParseCompoundStatement(ParsedAttributes &Attr,
+ bool isStmtExpr,
+ unsigned ScopeFlags);
StmtResult ParseCompoundStatementBody(bool isStmtExpr = false);
bool ParseParenExprOrCondition(ExprResult &ExprResult,
Decl *&DeclResult,
Modified: cfe/trunk/include/clang/Sema/Scope.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Scope.h?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Scope.h (original)
+++ cfe/trunk/include/clang/Sema/Scope.h Wed Jul 6 17:04:06 2011
@@ -84,7 +84,10 @@
/// ThisScope - This is the scope of a struct/union/class definition,
/// outside of any member function definition, where 'this' is nonetheless
/// usable.
- ThisScope = 0x1000
+ ThisScope = 0x1000,
+
+ /// TryScope - This is the scope of a C++ try statement.
+ TryScope = 0x2000
};
private:
/// The parent scope for this scope. This is null for the translation-unit
@@ -303,6 +306,9 @@
}
return false;
}
+
+ /// \brief Determine whether this scope is a C++ 'try' block.
+ bool isTryScope() const { return getFlags() & Scope::TryScope; }
typedef UsingDirectivesTy::iterator udir_iterator;
typedef UsingDirectivesTy::const_iterator const_udir_iterator;
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Wed Jul 6 17:04:06 2011
@@ -1336,7 +1336,8 @@
ExprResult PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
const VarDecl *NRVOCandidate,
QualType ResultType,
- Expr *Value);
+ Expr *Value,
+ bool AllowNRVO = true);
bool CanPerformCopyInitialization(const InitializedEntity &Entity,
ExprResult Init);
@@ -2885,8 +2886,11 @@
ExprResult ActOnCXXNullPtrLiteral(SourceLocation Loc);
//// ActOnCXXThrow - Parse throw expressions.
- ExprResult ActOnCXXThrow(SourceLocation OpLoc, Expr *expr);
- ExprResult CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E);
+ ExprResult ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *expr);
+ ExprResult BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
+ bool IsThrownVarInScope);
+ ExprResult CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E,
+ bool IsThrownVarInScope);
/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
Modified: cfe/trunk/lib/Parse/ParseExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseExprCXX.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseExprCXX.cpp (original)
+++ cfe/trunk/lib/Parse/ParseExprCXX.cpp Wed Jul 6 17:04:06 2011
@@ -787,12 +787,12 @@
case tok::r_brace:
case tok::colon:
case tok::comma:
- return Actions.ActOnCXXThrow(ThrowLoc, 0);
+ return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, 0);
default:
ExprResult Expr(ParseAssignmentExpression());
if (Expr.isInvalid()) return move(Expr);
- return Actions.ActOnCXXThrow(ThrowLoc, Expr.take());
+ return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, Expr.take());
}
}
Modified: cfe/trunk/lib/Parse/ParseStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseStmt.cpp (original)
+++ cfe/trunk/lib/Parse/ParseStmt.cpp Wed Jul 6 17:04:06 2011
@@ -647,6 +647,10 @@
SubStmt.get(), getCurScope());
}
+StmtResult Parser::ParseCompoundStatement(ParsedAttributes &Attr,
+ bool isStmtExpr) {
+ return ParseCompoundStatement(Attr, isStmtExpr, Scope::DeclScope);
+}
/// ParseCompoundStatement - Parse a "{}" block.
///
@@ -676,14 +680,15 @@
/// [OMP] flush-directive
///
StmtResult Parser::ParseCompoundStatement(ParsedAttributes &attrs,
- bool isStmtExpr) {
+ bool isStmtExpr,
+ unsigned ScopeFlags) {
//FIXME: Use attributes?
assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
// Enter a scope to hold everything within the compound stmt. Compound
// statements can always hold declarations.
- ParseScope CompoundScope(this, Scope::DeclScope);
+ ParseScope CompoundScope(this, ScopeFlags);
// Parse the statements in the body.
return ParseCompoundStatementBody(isStmtExpr);
@@ -1910,7 +1915,8 @@
return StmtError(Diag(Tok, diag::err_expected_lbrace));
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
ParsedAttributesWithRange attrs(AttrFactory);
- StmtResult TryBlock(ParseCompoundStatement(attrs));
+ StmtResult TryBlock(ParseCompoundStatement(attrs, /*isStmtExpr=*/false,
+ Scope::DeclScope|Scope::TryScope));
if (TryBlock.isInvalid())
return move(TryBlock);
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Wed Jul 6 17:04:06 2011
@@ -480,23 +480,63 @@
/// ActOnCXXThrow - Parse throw expressions.
ExprResult
-Sema::ActOnCXXThrow(SourceLocation OpLoc, Expr *Ex) {
+Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
+ bool IsThrownVarInScope = false;
+ if (Ex) {
+ // C++0x [class.copymove]p31:
+ // When certain criteria are met, an implementation is allowed to omit the
+ // copy/move construction of a class object [...]
+ //
+ // - in a throw-expression, when the operand is the name of a
+ // non-volatile automatic object (other than a function or catch-
+ // clause parameter) whose scope does not extend beyond the end of the
+ // innermost enclosing try-block (if there is one), the copy/move
+ // operation from the operand to the exception object (15.1) can be
+ // omitted by constructing the automatic object directly into the
+ // exception object
+ if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
+ if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
+ if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
+ for( ; S; S = S->getParent()) {
+ if (S->isDeclScope(Var)) {
+ IsThrownVarInScope = true;
+ break;
+ }
+
+ if (S->getFlags() &
+ (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
+ Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
+ Scope::TryScope))
+ break;
+ }
+ }
+ }
+ }
+
+ return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
+}
+
+ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
+ bool IsThrownVarInScope) {
// Don't report an error if 'throw' is used in system headers.
if (!getLangOptions().CXXExceptions &&
!getSourceManager().isInSystemHeader(OpLoc))
Diag(OpLoc, diag::err_exceptions_disabled) << "throw";
-
+
if (Ex && !Ex->isTypeDependent()) {
- ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex);
+ ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex, IsThrownVarInScope);
if (ExRes.isInvalid())
return ExprError();
Ex = ExRes.take();
}
- return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc));
+
+ return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc,
+ IsThrownVarInScope));
}
/// CheckCXXThrowOperand - Validate the operand of a throw.
-ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E) {
+ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E,
+ bool IsThrownVarInScope) {
// C++ [except.throw]p3:
// A throw-expression initializes a temporary object, called the exception
// object, the type of which is determined by removing any top-level
@@ -535,14 +575,28 @@
// Initialize the exception result. This implicitly weeds out
// abstract types or types with inaccessible copy constructors.
- const VarDecl *NRVOVariable = getCopyElisionCandidate(QualType(), E, false);
-
- // FIXME: Determine whether we can elide this copy per C++0x [class.copy]p32.
+
+ // C++0x [class.copymove]p31:
+ // When certain criteria are met, an implementation is allowed to omit the
+ // copy/move construction of a class object [...]
+ //
+ // - in a throw-expression, when the operand is the name of a
+ // non-volatile automatic object (other than a function or catch-clause
+ // parameter) whose scope does not extend beyond the end of the
+ // innermost enclosing try-block (if there is one), the copy/move
+ // operation from the operand to the exception object (15.1) can be
+ // omitted by constructing the automatic object directly into the
+ // exception object
+ const VarDecl *NRVOVariable = 0;
+ if (IsThrownVarInScope)
+ NRVOVariable = getCopyElisionCandidate(QualType(), E, false);
+
InitializedEntity Entity =
InitializedEntity::InitializeException(ThrowLoc, E->getType(),
- /*NRVO=*/false);
+ /*NRVO=*/NRVOVariable != 0);
Res = PerformMoveOrCopyInitialization(Entity, NRVOVariable,
- QualType(), E);
+ QualType(), E,
+ IsThrownVarInScope);
if (Res.isInvalid())
return ExprError();
E = Res.take();
Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Wed Jul 6 17:04:06 2011
@@ -1543,7 +1543,8 @@
Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
const VarDecl *NRVOCandidate,
QualType ResultType,
- Expr *Value) {
+ Expr *Value,
+ bool AllowNRVO) {
// C++0x [class.copy]p33:
// When the criteria for elision of a copy operation are met or would
// be met save for the fact that the source object is a function
@@ -1551,7 +1552,8 @@
// overload resolution to select the constructor for the copy is first
// performed as if the object were designated by an rvalue.
ExprResult Res = ExprError();
- if (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true)) {
+ if (AllowNRVO &&
+ (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) {
ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack,
Value->getType(), CK_LValueToRValue,
Value, VK_XValue);
Modified: cfe/trunk/lib/Sema/TreeTransform.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/TreeTransform.h (original)
+++ cfe/trunk/lib/Sema/TreeTransform.h Wed Jul 6 17:04:06 2011
@@ -1866,8 +1866,9 @@
///
/// By default, performs semantic analysis to build the new expression.
/// Subclasses may override this routine to provide different behavior.
- ExprResult RebuildCXXThrowExpr(SourceLocation ThrowLoc, Expr *Sub) {
- return getSema().ActOnCXXThrow(ThrowLoc, Sub);
+ ExprResult RebuildCXXThrowExpr(SourceLocation ThrowLoc, Expr *Sub,
+ bool IsThrownVariableInScope) {
+ return getSema().BuildCXXThrow(ThrowLoc, Sub, IsThrownVariableInScope);
}
/// \brief Build a new C++ default-argument expression.
@@ -6793,7 +6794,8 @@
SubExpr.get() == E->getSubExpr())
return SemaRef.Owned(E);
- return getDerived().RebuildCXXThrowExpr(E->getThrowLoc(), SubExpr.get());
+ return getDerived().RebuildCXXThrowExpr(E->getThrowLoc(), SubExpr.get(),
+ E->isThrownVariableInScope());
}
template<typename Derived>
Modified: cfe/trunk/lib/Serialization/ASTReaderStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderStmt.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderStmt.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderStmt.cpp Wed Jul 6 17:04:06 2011
@@ -1172,8 +1172,9 @@
void ASTStmtReader::VisitCXXThrowExpr(CXXThrowExpr *E) {
VisitExpr(E);
- E->setThrowLoc(ReadSourceLocation(Record, Idx));
- E->setSubExpr(Reader.ReadSubExpr());
+ E->ThrowLoc = ReadSourceLocation(Record, Idx);
+ E->Op = Reader.ReadSubExpr();
+ E->IsThrownVariableInScope = Record[Idx++];
}
void ASTStmtReader::VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
Modified: cfe/trunk/lib/Serialization/ASTWriterStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriterStmt.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriterStmt.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriterStmt.cpp Wed Jul 6 17:04:06 2011
@@ -1174,6 +1174,7 @@
VisitExpr(E);
Writer.AddSourceLocation(E->getThrowLoc(), Record);
Writer.AddStmt(E->getSubExpr());
+ Record.push_back(E->isThrownVariableInScope());
Code = serialization::EXPR_CXX_THROW;
}
Modified: cfe/trunk/test/CXX/special/class.copy/p33-0x.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/special/class.copy/p33-0x.cpp?rev=134548&r1=134547&r2=134548&view=diff
==============================================================================
--- cfe/trunk/test/CXX/special/class.copy/p33-0x.cpp (original)
+++ cfe/trunk/test/CXX/special/class.copy/p33-0x.cpp Wed Jul 6 17:04:06 2011
@@ -23,3 +23,35 @@
throw x2;
}
+namespace PR10142 {
+ struct X {
+ X();
+ X(X&&);
+ X(const X&) = delete; // expected-note 2{{function has been explicitly marked deleted here}}
+ };
+
+ void f(int i) {
+ X x;
+ try {
+ X x2;
+ if (i)
+ throw x2; // okay
+ throw x; // expected-error{{call to deleted constructor of 'PR10142::X'}}
+ } catch (...) {
+ }
+ }
+
+ template<typename T>
+ void f2(int i) {
+ T x;
+ try {
+ T x2;
+ if (i)
+ throw x2; // okay
+ throw x; // expected-error{{call to deleted constructor of 'PR10142::X'}}
+ } catch (...) {
+ }
+ }
+
+ template void f2<X>(int); // expected-note{{in instantiation of function template specialization 'PR10142::f2<PR10142::X>' requested here}}
+}
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