Introduce basic ASTs for lambda expressions. This covers:
- Capturing variables by-reference and by-copy within a lambda
- The representation of lambda captures
- The creation of the non-static data members in the lambda class
that store the captured variables
- The initialization of the non-static data members from the
captured variables
- Pretty-printing lambda expressions
There are a number of FIXMEs, both explicit and implied, including:
- Creating a field for a capture of 'this'
- Improved diagnostics for initialization failures when capturing
variables by copy
- Dealing with temporaries created during said initialization
- Template instantiation
- AST (de-)serialization
- Binding and returning the lambda expression; turning it into a
proper temporary
- Lots and lots of semantic constraints
- Parameter pack captures
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149977 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 8738e5f..f2ebd8c 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2019,6 +2019,16 @@
return MergeCanThrow(CT, CanSubExprsThrow(C, this));
}
+ case LambdaExprClass: {
+ const LambdaExpr *Lambda = cast<LambdaExpr>(this);
+ CanThrowResult CT = Expr::CT_Cannot;
+ for (LambdaExpr::capture_init_iterator Cap = Lambda->capture_init_begin(),
+ CapEnd = Lambda->capture_init_end();
+ Cap != CapEnd; ++Cap)
+ CT = MergeCanThrow(CT, (*Cap)->CanThrow(C));
+ return CT;
+ }
+
case CXXNewExprClass: {
CanThrowResult CT;
if (isTypeDependent())
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index df223eb..51dd57c 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -712,6 +712,113 @@
}
}
+LambdaExpr::Capture::Capture(SourceLocation Loc, bool Implicit,
+ LambdaCaptureKind Kind, VarDecl *Var,
+ SourceLocation EllipsisLoc)
+ : VarAndBits(Var, 0), Loc(Loc), EllipsisLoc(EllipsisLoc)
+{
+ unsigned Bits = 0;
+ if (Implicit)
+ Bits |= Capture_Implicit;
+
+ switch (Kind) {
+ case LCK_This:
+ assert(Var == 0 && "'this' capture cannot have a variable!");
+ break;
+
+ case LCK_ByCopy:
+ Bits |= Capture_ByCopy;
+ // Fall through
+ case LCK_ByRef:
+ assert(Var && "capture must have a variable!");
+ break;
+ }
+ VarAndBits.setInt(Bits);
+}
+
+LambdaCaptureKind LambdaExpr::Capture::getCaptureKind() const {
+ if (capturesThis())
+ return LCK_This;
+
+ return (VarAndBits.getInt() & Capture_ByCopy)? LCK_ByCopy : LCK_ByRef;
+}
+
+LambdaExpr::LambdaExpr(QualType T,
+ SourceRange IntroducerRange,
+ LambdaCaptureDefault CaptureDefault,
+ ArrayRef<Capture> Captures,
+ bool ExplicitParams,
+ ArrayRef<Expr *> CaptureInits,
+ SourceLocation ClosingBrace)
+ : Expr(LambdaExprClass, T, VK_RValue, OK_Ordinary,
+ T->isDependentType(), T->isDependentType(), T->isDependentType(),
+ /*ContainsUnexpandedParameterPack=*/false),
+ IntroducerRange(IntroducerRange),
+ NumCaptures(Captures.size()),
+ NumExplicitCaptures(0),
+ CaptureDefault(CaptureDefault),
+ ExplicitParams(ExplicitParams),
+ ClosingBrace(ClosingBrace)
+{
+ assert(CaptureInits.size() == Captures.size() && "Wrong number of arguments");
+
+ // Copy captures.
+ // FIXME: Do we need to update "contains unexpanded parameter pack" here?
+ Capture *ToCapture = reinterpret_cast<Capture *>(this + 1);
+ for (unsigned I = 0, N = Captures.size(); I != N; ++I) {
+ if (Captures[I].isExplicit())
+ ++NumExplicitCaptures;
+ *ToCapture++ = Captures[I];
+ }
+
+ // Copy initialization expressions for the non-static data members.
+ Stmt **Stored = getStoredStmts();
+ for (unsigned I = 0, N = CaptureInits.size(); I != N; ++I)
+ *Stored++ = CaptureInits[I];
+
+ // Copy the body of the lambda.
+ *Stored++ = getCallOperator()->getBody();
+}
+
+LambdaExpr *LambdaExpr::Create(ASTContext &Context,
+ CXXRecordDecl *Class,
+ SourceRange IntroducerRange,
+ LambdaCaptureDefault CaptureDefault,
+ ArrayRef<Capture> Captures,
+ bool ExplicitParams,
+ ArrayRef<Expr *> CaptureInits,
+ SourceLocation ClosingBrace) {
+ // Determine the type of the expression (i.e., the type of the
+ // function object we're creating).
+ QualType T = Context.getTypeDeclType(Class);
+ size_t Size = sizeof(LambdaExpr) + sizeof(Capture) * Captures.size()
+ + sizeof(Stmt *) * (Captures.size() + 1);
+
+ void *Mem = Context.Allocate(Size, llvm::alignOf<LambdaExpr>());
+ return new (Mem) LambdaExpr(T, IntroducerRange, CaptureDefault,
+ Captures, ExplicitParams, CaptureInits,
+ ClosingBrace);
+}
+
+CXXRecordDecl *LambdaExpr::getLambdaClass() const {
+ return getType()->getAsCXXRecordDecl();
+}
+
+CXXMethodDecl *LambdaExpr::getCallOperator() const {
+ CXXRecordDecl *Record = getLambdaClass();
+ DeclarationName Name
+ = Record->getASTContext().DeclarationNames.getCXXOperatorName(OO_Call);
+ DeclContext::lookup_result Calls = Record->lookup(Name);
+ assert(Calls.first != Calls.second && "Missing lambda call operator!");
+ CXXMethodDecl *Result = cast<CXXMethodDecl>(*Calls.first++);
+ assert(Calls.first == Calls.second && "More than lambda one call operator?");
+ return Result;
+}
+
+bool LambdaExpr::isMutable() const {
+ return (getCallOperator()->getTypeQualifiers() & Qualifiers::Const) == 0;
+}
+
ExprWithCleanups::ExprWithCleanups(Expr *subexpr,
ArrayRef<CleanupObject> objects)
: Expr(ExprWithCleanupsClass, subexpr->getType(),
diff --git a/lib/AST/ExprClassification.cpp b/lib/AST/ExprClassification.cpp
index 311b805..79d8dc4 100644
--- a/lib/AST/ExprClassification.cpp
+++ b/lib/AST/ExprClassification.cpp
@@ -330,6 +330,7 @@
// Some C++ expressions are always class temporaries.
case Expr::CXXConstructExprClass:
case Expr::CXXTemporaryObjectExprClass:
+ case Expr::LambdaExprClass:
return Cl::CL_ClassTemporary;
case Expr::VAArgExprClass:
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index bb7042d..283132a 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -6086,6 +6086,7 @@
case Expr::PseudoObjectExprClass:
case Expr::AtomicExprClass:
case Expr::InitListExprClass:
+ case Expr::LambdaExprClass:
return ICEDiag(2, E->getLocStart());
case Expr::SizeOfPackExprClass:
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 37ae626..e39031d 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2247,6 +2247,7 @@
case Expr::ImplicitValueInitExprClass:
case Expr::InitListExprClass:
case Expr::ParenListExprClass:
+ case Expr::LambdaExprClass:
llvm_unreachable("unexpected statement kind");
// FIXME: invent manglings for all these.
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index 7077be1..1e2a494 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -1263,6 +1263,98 @@
OS << ")";
}
+void StmtPrinter::VisitLambdaExpr(LambdaExpr *Node) {
+ OS << '[';
+ bool NeedComma = false;
+ switch (Node->getCaptureDefault()) {
+ case LCD_None:
+ break;
+
+ case LCD_ByCopy:
+ OS << '=';
+ NeedComma = true;
+ break;
+
+ case LCD_ByRef:
+ OS << '&';
+ NeedComma = true;
+ break;
+ }
+ for (LambdaExpr::capture_iterator C = Node->explicit_capture_begin(),
+ CEnd = Node->explicit_capture_end();
+ C != CEnd;
+ ++C) {
+ if (NeedComma)
+ OS << ", ";
+ NeedComma = true;
+
+ switch (C->getCaptureKind()) {
+ case LCK_This:
+ OS << "this";
+ break;
+
+ case LCK_ByRef:
+ if (Node->getCaptureDefault() != LCD_ByRef)
+ OS << '&';
+ OS << C->getCapturedVar()->getName();
+ break;
+
+ case LCK_ByCopy:
+ if (Node->getCaptureDefault() != LCD_ByCopy)
+ OS << '=';
+ OS << C->getCapturedVar()->getName();
+ break;
+ }
+ }
+ OS << ']';
+
+ if (Node->hasExplicitParameters()) {
+ OS << " (";
+ CXXMethodDecl *Method = Node->getCallOperator();
+ NeedComma = false;
+ for (CXXMethodDecl::param_iterator P = Method->param_begin(),
+ PEnd = Method->param_end();
+ P != PEnd; ++P) {
+ if (NeedComma) {
+ OS << ", ";
+ } else {
+ NeedComma = true;
+ }
+ std::string ParamStr = (*P)->getNameAsString();
+ (*P)->getOriginalType().getAsStringInternal(ParamStr, Policy);
+ OS << ParamStr;
+ }
+ if (Method->isVariadic()) {
+ if (NeedComma)
+ OS << ", ";
+ OS << "...";
+ }
+ OS << ')';
+
+ if (Node->isMutable())
+ OS << " mutable";
+
+ const FunctionProtoType *Proto
+ = Method->getType()->getAs<FunctionProtoType>();
+ {
+ std::string ExceptionSpec;
+ Proto->printExceptionSpecification(ExceptionSpec, Policy);
+ OS << ExceptionSpec;
+ }
+
+ // FIXME: Attributes
+
+ // FIXME: Suppress trailing return type if it wasn't specified in
+ // the source.
+ OS << " -> " << Proto->getResultType().getAsString(Policy);
+ }
+
+ // Print the body.
+ CompoundStmt *Body = Node->getBody();
+ OS << ' ';
+ PrintStmt(Body);
+}
+
void StmtPrinter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *Node) {
if (TypeSourceInfo *TSInfo = Node->getTypeSourceInfo())
OS << TSInfo->getType().getAsString(Policy) << "()";
diff --git a/lib/AST/StmtProfile.cpp b/lib/AST/StmtProfile.cpp
index 2fb67d9..1d58fd7 100644
--- a/lib/AST/StmtProfile.cpp
+++ b/lib/AST/StmtProfile.cpp
@@ -790,6 +790,24 @@
}
void
+StmtProfiler::VisitLambdaExpr(const LambdaExpr *S) {
+ VisitExpr(S);
+ for (LambdaExpr::capture_iterator C = S->explicit_capture_begin(),
+ CEnd = S->explicit_capture_end();
+ C != CEnd; ++C) {
+ ID.AddInteger(C->getCaptureKind());
+ if (C->capturesVariable()) {
+ VisitDecl(C->getCapturedVar());
+ ID.AddBoolean(C->isPackExpansion());
+ }
+ }
+ // Note: If we actually needed to be able to match lambda
+ // expressions, we would have to consider parameters and return type
+ // here, among other things.
+ VisitStmt(S->getBody());
+}
+
+void
StmtProfiler::VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *S) {
VisitExpr(S);
}
diff --git a/lib/AST/TypePrinter.cpp b/lib/AST/TypePrinter.cpp
index b6d7110..7e9e7c5 100644
--- a/lib/AST/TypePrinter.cpp
+++ b/lib/AST/TypePrinter.cpp
@@ -397,6 +397,35 @@
print(T->getElementType(), S);
}
+void
+FunctionProtoType::printExceptionSpecification(std::string &S,
+ PrintingPolicy Policy) const {
+
+ if (hasDynamicExceptionSpec()) {
+ S += " throw(";
+ if (getExceptionSpecType() == EST_MSAny)
+ S += "...";
+ else
+ for (unsigned I = 0, N = getNumExceptions(); I != N; ++I) {
+ if (I)
+ S += ", ";
+
+ S += getExceptionType(I).getAsString(Policy);
+ }
+ S += ")";
+ } else if (isNoexceptExceptionSpec(getExceptionSpecType())) {
+ S += " noexcept";
+ if (getExceptionSpecType() == EST_ComputedNoexcept) {
+ S += "(";
+ llvm::raw_string_ostream EOut(S);
+ getNoexceptExpr()->printPretty(EOut, 0, Policy);
+ EOut.flush();
+ S += EOut.str();
+ S += ")";
+ }
+ }
+}
+
void TypePrinter::printFunctionProto(const FunctionProtoType *T,
std::string &S) {
// If needed for precedence reasons, wrap the inner part in grouping parens.
@@ -470,33 +499,7 @@
S += " &&";
break;
}
-
- if (T->hasDynamicExceptionSpec()) {
- S += " throw(";
- if (T->getExceptionSpecType() == EST_MSAny)
- S += "...";
- else
- for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I) {
- if (I)
- S += ", ";
-
- std::string ExceptionType;
- print(T->getExceptionType(I), ExceptionType);
- S += ExceptionType;
- }
- S += ")";
- } else if (isNoexceptExceptionSpec(T->getExceptionSpecType())) {
- S += " noexcept";
- if (T->getExceptionSpecType() == EST_ComputedNoexcept) {
- S += "(";
- llvm::raw_string_ostream EOut(S);
- T->getNoexceptExpr()->printPretty(EOut, 0, Policy);
- EOut.flush();
- S += EOut.str();
- S += ")";
- }
- }
-
+ T->printExceptionSpecification(S, Policy);
print(T->getResultType(), S);
}