Implement C++1y decltype(auto).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180610 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index d7f8e98..f1fbbb1 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -674,15 +674,15 @@
T.getCloseLocation());
}
-/// ParseDecltypeSpecifier - Parse a C++0x decltype specifier.
+/// ParseDecltypeSpecifier - Parse a C++11 decltype specifier.
///
/// 'decltype' ( expression )
+/// 'decltype' ( 'auto' ) [C++1y]
///
SourceLocation Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
assert((Tok.is(tok::kw_decltype) || Tok.is(tok::annot_decltype))
&& "Not a decltype specifier");
-
ExprResult Result;
SourceLocation StartLoc = Tok.getLocation();
SourceLocation EndLoc;
@@ -709,29 +709,44 @@
StartLoc : T.getOpenLocation();
}
- // Parse the expression
+ // Check for C++1y 'decltype(auto)'.
+ if (Tok.is(tok::kw_auto)) {
+ // No need to disambiguate here: an expression can't start with 'auto',
+ // because the typename-specifier in a function-style cast operation can't
+ // be 'auto'.
+ Diag(Tok.getLocation(),
+ getLangOpts().CPlusPlus1y
+ ? diag::warn_cxx11_compat_decltype_auto_type_specifier
+ : diag::ext_decltype_auto_type_specifier);
+ ConsumeToken();
+ } else {
+ // Parse the expression
- // C++0x [dcl.type.simple]p4:
- // The operand of the decltype specifier is an unevaluated operand.
- EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated,
- 0, /*IsDecltype=*/true);
- Result = ParseExpression();
- if (Result.isInvalid()) {
- DS.SetTypeSpecError();
- if (SkipUntil(tok::r_paren, /*StopAtSemi=*/true, /*DontConsume=*/true)) {
- EndLoc = ConsumeParen();
- } else {
- if (PP.isBacktrackEnabled() && Tok.is(tok::semi)) {
- // Backtrack to get the location of the last token before the semi.
- PP.RevertCachedTokens(2);
- ConsumeToken(); // the semi.
- EndLoc = ConsumeAnyToken();
- assert(Tok.is(tok::semi));
+ // C++11 [dcl.type.simple]p4:
+ // The operand of the decltype specifier is an unevaluated operand.
+ EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated,
+ 0, /*IsDecltype=*/true);
+ Result = ParseExpression();
+ if (Result.isInvalid()) {
+ DS.SetTypeSpecError();
+ if (SkipUntil(tok::r_paren, /*StopAtSemi=*/true,
+ /*DontConsume=*/true)) {
+ EndLoc = ConsumeParen();
} else {
- EndLoc = Tok.getLocation();
+ if (PP.isBacktrackEnabled() && Tok.is(tok::semi)) {
+ // Backtrack to get the location of the last token before the semi.
+ PP.RevertCachedTokens(2);
+ ConsumeToken(); // the semi.
+ EndLoc = ConsumeAnyToken();
+ assert(Tok.is(tok::semi));
+ } else {
+ EndLoc = Tok.getLocation();
+ }
}
+ return EndLoc;
}
- return EndLoc;
+
+ Result = Actions.ActOnDecltypeExpression(Result.take());
}
// Match the ')'
@@ -743,7 +758,6 @@
return T.getCloseLocation();
}
- Result = Actions.ActOnDecltypeExpression(Result.take());
if (Result.isInvalid()) {
DS.SetTypeSpecError();
return T.getCloseLocation();
@@ -751,12 +765,16 @@
EndLoc = T.getCloseLocation();
}
+ assert(!Result.isInvalid());
const char *PrevSpec = 0;
unsigned DiagID;
// Check for duplicate type specifiers (e.g. "int decltype(a)").
- if (DS.SetTypeSpecType(DeclSpec::TST_decltype, StartLoc, PrevSpec,
- DiagID, Result.release())) {
+ if (Result.get()
+ ? DS.SetTypeSpecType(DeclSpec::TST_decltype, StartLoc, PrevSpec,
+ DiagID, Result.release())
+ : DS.SetTypeSpecType(DeclSpec::TST_decltype_auto, StartLoc, PrevSpec,
+ DiagID)) {
Diag(StartLoc, DiagID) << PrevSpec;
DS.SetTypeSpecError();
}
@@ -773,8 +791,10 @@
PP.EnterToken(Tok);
Tok.setKind(tok::annot_decltype);
- setExprAnnotation(Tok, DS.getTypeSpecType() == TST_decltype ?
- DS.getRepAsExpr() : ExprResult());
+ setExprAnnotation(Tok,
+ DS.getTypeSpecType() == TST_decltype ? DS.getRepAsExpr() :
+ DS.getTypeSpecType() == TST_decltype_auto ? ExprResult() :
+ ExprError());
Tok.setAnnotationEndLoc(EndLoc);
Tok.setLocation(StartLoc);
PP.AnnotateCachedTokens(Tok);
@@ -2267,11 +2287,10 @@
SkipUntil(tok::comma, true, true);
else if (ThisDecl)
Actions.AddInitializerToDecl(ThisDecl, Init.get(), EqualLoc.isInvalid(),
- DS.getTypeSpecType() == DeclSpec::TST_auto);
+ DS.containsPlaceholderType());
} else if (ThisDecl && DS.getStorageClassSpec() == DeclSpec::SCS_static) {
// No initializer.
- Actions.ActOnUninitializedDecl(ThisDecl,
- DS.getTypeSpecType() == DeclSpec::TST_auto);
+ Actions.ActOnUninitializedDecl(ThisDecl, DS.containsPlaceholderType());
}
if (ThisDecl) {