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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

  

llvm-svn: 72555
This commit is contained in:
Douglas Gregor 2009-05-28 23:31:59 +00:00
parent 2a69547f38
commit d6ab8744dc
12 changed files with 101 additions and 19 deletions
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7
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -253,6 +253,13 @@ def err_abstract_type_in_decl : Error<
def err_allocation_of_abstract_type : Error<
"allocation of an object of abstract type %0">;
def err_type_defined_in_type_specifier : Error<
"%0 can not be defined in a type specifier">;
def err_type_defined_in_result_type : Error<
"%0 can not be defined in the result type of a function">;
def err_type_defined_in_param_type : Error<
"%0 can not be defined in a parameter type">;
def note_pure_virtual_function : Note<
"pure virtual function %0">;

3
clang/include/clang/Parse/Action.h
View File

@ -397,7 +397,8 @@ public:
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) {
// TagType is an instance of DeclSpec::TST, indicating what kind of tag this
// is (struct/union/enum/class).
return DeclPtrTy();

7
clang/include/clang/Parse/DeclSpec.h
View File

@ -114,6 +114,7 @@ private:
/*TSC*/unsigned TypeSpecComplex : 2;
/*TSS*/unsigned TypeSpecSign : 2;
/*TST*/unsigned TypeSpecType : 5;
bool TypeSpecOwned : 1;
// type-qualifiers
unsigned TypeQualifiers : 3; // Bitwise OR of TQ.
@ -129,7 +130,7 @@ private:
/// TypeRep - This contains action-specific information about a specific TST.
/// For example, for a typedef or struct, it might contain the declaration for
/// these.
ActionBase::TypeTy *TypeRep;
void *TypeRep;
// attributes.
AttributeList *AttrList;
@ -168,6 +169,7 @@ public:
TypeSpecComplex(TSC_unspecified),
TypeSpecSign(TSS_unspecified),
TypeSpecType(TST_unspecified),
TypeSpecOwned(false),
TypeQualifiers(TSS_unspecified),
FS_inline_specified(false),
FS_virtual_specified(false),
@ -201,6 +203,7 @@ public:
TSC getTypeSpecComplex() const { return (TSC)TypeSpecComplex; }
TSS getTypeSpecSign() const { return (TSS)TypeSpecSign; }
TST getTypeSpecType() const { return (TST)TypeSpecType; }
bool isTypeSpecOwned() const { return TypeSpecOwned; }
void *getTypeRep() const { return TypeRep; }
const SourceRange &getSourceRange() const { return Range; }
@ -272,7 +275,7 @@ public:
bool SetTypeSpecComplex(TSC C, SourceLocation Loc, const char *&PrevSpec);
bool SetTypeSpecSign(TSS S, SourceLocation Loc, const char *&PrevSpec);
bool SetTypeSpecType(TST T, SourceLocation Loc, const char *&PrevSpec,
void *Rep = 0);
void *Rep = 0, bool Owned = false);
bool SetTypeSpecError();
bool SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,

3
clang/lib/Frontend/PrintParserCallbacks.cpp
View File

@ -195,7 +195,8 @@ namespace {
virtual DeclPtrTy ActOnTag(Scope *S, unsigned TagType, TagKind TK,
SourceLocation KWLoc, const CXXScopeSpec &SS,
IdentifierInfo *Name, SourceLocation NameLoc,
AttributeList *Attr, AccessSpecifier AS) {
AttributeList *Attr, AccessSpecifier AS,
bool &Owned) {
// TagType is an instance of DeclSpec::TST, indicating what kind of tag this
// is (struct/union/enum/class).
Out << __FUNCTION__ << "\n";

4
clang/lib/Parse/DeclSpec.cpp
View File

@ -241,12 +241,14 @@ bool DeclSpec::SetTypeSpecSign(TSS S, SourceLocation Loc,
}
bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
const char *&PrevSpec, void *Rep) {
const char *&PrevSpec, void *Rep,
bool Owned) {
if (TypeSpecType != TST_unspecified)
return BadSpecifier((TST)TypeSpecType, PrevSpec);
TypeSpecType = T;
TypeRep = Rep;
TSTLoc = Loc;
TypeSpecOwned = Owned;
return false;
}

6
clang/lib/Parse/ParseDecl.cpp
View File

@ -1460,8 +1460,10 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
TK = Action::TK_Declaration;
else
TK = Action::TK_Reference;
bool Owned = false;
DeclPtrTy TagDecl = Actions.ActOnTag(CurScope, DeclSpec::TST_enum, TK,
StartLoc, SS, Name, NameLoc, Attr, AS);
StartLoc, SS, Name, NameLoc, Attr, AS,
Owned);
if (Tok.is(tok::l_brace))
ParseEnumBody(StartLoc, TagDecl);
@ -1469,7 +1471,7 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
// TODO: semantic analysis on the declspec for enums.
const char *PrevSpec = 0;
if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc, PrevSpec,
TagDecl.getAs<void>()))
TagDecl.getAs<void>(), Owned))
Diag(StartLoc, diag::err_invalid_decl_spec_combination) << PrevSpec;
}

5
clang/lib/Parse/ParseDeclCXX.cpp
View File

@ -479,6 +479,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
// FIXME: When TK == TK_Reference and we have a template-id, we need
// to turn that template-id into a type.
bool Owned = false;
if (TemplateId && TK != Action::TK_Reference) {
// Explicit specialization, class template partial specialization,
// or explicit instantiation.
@ -582,7 +583,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
// Declaration or definition of a class type
TagOrTempResult = Actions.ActOnTag(CurScope, TagType, TK, StartLoc, SS,
Name, NameLoc, Attr, AS);
Name, NameLoc, Attr, AS, Owned);
}
// Parse the optional base clause (C++ only).
@ -608,7 +609,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
}
if (DS.SetTypeSpecType(TagType, StartLoc, PrevSpec,
TagOrTempResult.get().getAs<void>()))
TagOrTempResult.get().getAs<void>(), Owned))
Diag(StartLoc, diag::err_invalid_decl_spec_combination) << PrevSpec;
if (DS.isFriendSpecified())

6
clang/lib/Sema/Sema.h
View File

@ -346,7 +346,8 @@ public:
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 @@ public:
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,

15
clang/lib/Sema/SemaDecl.cpp
View File

@ -2835,7 +2835,15 @@ Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
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
@ -3316,11 +3324,13 @@ bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
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 @@ CreateNewDecl:
CurContext->addDecl(Context, New);
}
OwnedDecl = true;
return DeclPtrTy::make(New);
}

3
clang/lib/Sema/SemaTemplate.cpp
View File

@ -2357,8 +2357,9 @@ Sema::ActOnExplicitInstantiation(Scope *S, SourceLocation TemplateLoc,
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;

32
clang/lib/Sema/SemaType.cpp
View File

@ -604,7 +604,12 @@ QualType Sema::BuildFunctionType(QualType T,
/// 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 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip) {
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 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip) {
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 @@ Sema::TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
// 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;
if (getLangOptions().CPlusPlus) {
// Check that there are no default arguments (C++ only).
if (getLangOptions().CPlusPlus)
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();
}

25
clang/test/SemaCXX/type-definition-in-specifier.cpp Normal file
View File

@ -0,0 +1,25 @@
// RUN: clang-cc -fsyntax-only -verify %s
struct S0;
struct S1;
struct S2;
struct S3;
struct S4;
struct S5;
struct S6;
struct S0 { int x; };
void f0() {
typedef struct S1 { int x; } S1_typedef;
(void)((struct S2 { int x; }*)0); // expected-error{{can not be defined}}
struct S3 { int x; } s3;
(void)static_cast<struct S4 { int x; } *>(0); // expected-error{{can not be defined}}
}
struct S5 { int x; } f1() { return S5(); } // expected-error{{result type}}
void f2(struct S6 { int x; } p); // expected-error{{parameter type}}