When we parse a tag specifier, keep track of whether that tag
specifier resulted in the creation of a new TagDecl node, which
happens either when the tag specifier was a definition or when the tag
specifier was the first declaration of that tag type. This information
has several uses, the first of which is implemented in this commit:
1) In C++, one is not allowed to define tag types within a type
specifier (e.g., static_cast<struct S { int x; } *>(0) is
ill-formed) or within the result or parameter types of a
function. We now diagnose this.
2) We can extend DeclGroups to contain information about any tags
that are declared/defined within the declaration specifiers of a
variable, e.g.,
struct Point { int x, y, z; } p;
This will help improve AST printing and template instantiation,
among other things.
3) For C99, we can keep track of whether a tag type is defined
within the type of a parameter, to properly cope with cases like,
e.g.,
int bar(struct T2 { int x; } y) {
struct T2 z;
}
We can also do similar things wherever there is a type specifier,
e.g., to keep track of where the definition of S occurs in this
legal C99 code:
(struct S { int x, y; } *)0
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 0a285bd..fae5a92 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -346,7 +346,8 @@
QualType *ParamTypes, unsigned NumParamTypes,
bool Variadic, unsigned Quals,
SourceLocation Loc, DeclarationName Entity);
- QualType GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip = 0);
+ QualType GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip = 0,
+ TagDecl **OwnedDecl = 0);
DeclarationName GetNameForDeclarator(Declarator &D);
QualType ObjCGetTypeForMethodDefinition(DeclPtrTy D);
@@ -444,7 +445,8 @@
virtual DeclPtrTy ActOnTag(Scope *S, unsigned TagSpec, TagKind TK,
SourceLocation KWLoc, const CXXScopeSpec &SS,
IdentifierInfo *Name, SourceLocation NameLoc,
- AttributeList *Attr, AccessSpecifier AS);
+ AttributeList *Attr, AccessSpecifier AS,
+ bool &OwnedDecl);
virtual void ActOnDefs(Scope *S, DeclPtrTy TagD, SourceLocation DeclStart,
IdentifierInfo *ClassName,
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 7b36b13..6a2e309 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2835,8 +2835,16 @@
if (getLangOptions().CPlusPlus)
CheckExtraCXXDefaultArguments(D);
- QualType parmDeclType = GetTypeForDeclarator(D, S);
+ TagDecl *OwnedDecl = 0;
+ QualType parmDeclType = GetTypeForDeclarator(D, S, /*Skip=*/0, &OwnedDecl);
+ if (getLangOptions().CPlusPlus && OwnedDecl && OwnedDecl->isDefinition()) {
+ // C++ [dcl.fct]p6:
+ // Types shall not be defined in return or parameter types.
+ Diag(OwnedDecl->getLocation(), diag::err_type_defined_in_param_type)
+ << Context.getTypeDeclType(OwnedDecl);
+ }
+
// TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
// Can this happen for params? We already checked that they don't conflict
// among each other. Here they can only shadow globals, which is ok.
@@ -3316,11 +3324,13 @@
Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagKind TK,
SourceLocation KWLoc, const CXXScopeSpec &SS,
IdentifierInfo *Name, SourceLocation NameLoc,
- AttributeList *Attr, AccessSpecifier AS) {
+ AttributeList *Attr, AccessSpecifier AS,
+ bool &OwnedDecl) {
// If this is not a definition, it must have a name.
assert((Name != 0 || TK == TK_Definition) &&
"Nameless record must be a definition!");
+ OwnedDecl = false;
TagDecl::TagKind Kind;
switch (TagSpec) {
default: assert(0 && "Unknown tag type!");
@@ -3645,6 +3655,7 @@
CurContext->addDecl(Context, New);
}
+ OwnedDecl = true;
return DeclPtrTy::make(New);
}
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index b15ce29..179e27d 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -2357,8 +2357,9 @@
SourceLocation NameLoc,
AttributeList *Attr) {
+ bool Owned = false;
DeclPtrTy TagD = ActOnTag(S, TagSpec, Action::TK_Reference,
- KWLoc, SS, Name, NameLoc, Attr, AS_none);
+ KWLoc, SS, Name, NameLoc, Attr, AS_none, Owned);
if (!TagD)
return true;
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 298a6cd..83f9b60 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -604,7 +604,12 @@
/// GetTypeForDeclarator - Convert the type for the specified
/// declarator to Type instances. Skip the outermost Skip type
/// objects.
-QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip) {
+///
+/// If OwnedDecl is non-NULL, and this declarator's decl-specifier-seq
+/// owns the declaration of a type (e.g., the definition of a struct
+/// type), then *OwnedDecl will receive the owned declaration.
+QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip,
+ TagDecl **OwnedDecl) {
bool OmittedReturnType = false;
if (D.getContext() == Declarator::BlockLiteralContext
@@ -637,6 +642,8 @@
T = ConvertDeclSpecToType(DS, D.getIdentifierLoc(), isInvalid);
if (isInvalid)
D.setInvalidType(true);
+ else if (OwnedDecl && DS.isTypeSpecOwned())
+ *OwnedDecl = cast<TagDecl>((Decl *)DS.getTypeRep());
}
break;
}
@@ -717,6 +724,15 @@
D.setInvalidType(true);
}
+ if (getLangOptions().CPlusPlus && D.getDeclSpec().isTypeSpecOwned()) {
+ // C++ [dcl.fct]p6:
+ // Types shall not be defined in return or parameter types.
+ TagDecl *Tag = cast<TagDecl>((Decl *)D.getDeclSpec().getTypeRep());
+ if (Tag->isDefinition())
+ Diag(Tag->getLocation(), diag::err_type_defined_in_result_type)
+ << Context.getTypeDeclType(Tag);
+ }
+
if (FTI.NumArgs == 0) {
if (getLangOptions().CPlusPlus) {
// C++ 8.3.5p2: If the parameter-declaration-clause is empty, the
@@ -971,14 +987,24 @@
// the parser.
assert(D.getIdentifier() == 0 && "Type name should have no identifier!");
- QualType T = GetTypeForDeclarator(D, S);
+ TagDecl *OwnedTag = 0;
+ QualType T = GetTypeForDeclarator(D, S, /*Skip=*/0, &OwnedTag);
if (D.isInvalidType())
return true;
- // Check that there are no default arguments (C++ only).
- if (getLangOptions().CPlusPlus)
+ if (getLangOptions().CPlusPlus) {
+ // Check that there are no default arguments (C++ only).
CheckExtraCXXDefaultArguments(D);
+ // C++0x [dcl.type]p3:
+ // A type-specifier-seq shall not define a class or enumeration
+ // unless it appears in the type-id of an alias-declaration
+ // (7.1.3).
+ if (OwnedTag && OwnedTag->isDefinition())
+ Diag(OwnedTag->getLocation(), diag::err_type_defined_in_type_specifier)
+ << Context.getTypeDeclType(OwnedTag);
+ }
+
return T.getAsOpaquePtr();
}