Add support for C++ default arguments, and rework Parse-Sema
interaction for function parameters, fixing PR2046.
Patch by Doug Gregor!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49369 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 0f464a0..5451ec2 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -263,9 +263,10 @@
}
}
-/// MergeFunctionDecl - We just parsed a function 'New' which has the same name
-/// and scope as a previous declaration 'Old'. Figure out how to resolve this
-/// situation, merging decls or emitting diagnostics as appropriate.
+/// MergeFunctionDecl - We just parsed a function 'New' from
+/// declarator D which has the same name and scope as a previous
+/// declaration 'Old'. Figure out how to resolve this situation,
+/// merging decls or emitting diagnostics as appropriate.
///
FunctionDecl *Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) {
// Verify the old decl was also a function.
@@ -276,17 +277,24 @@
Diag(OldD->getLocation(), diag::err_previous_definition);
return New;
}
-
+
MergeAttributes(New, Old);
-
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
- // Function types need to be compatible, not identical. This handles
+ // C++ [dcl.fct]p3:
+ // All declarations for a function shall agree exactly in both the
+ // return type and the parameter-type-list.
+ if (getLangOptions().CPlusPlus && OldQType == NewQType)
+ return MergeCXXFunctionDecl(New, Old);
+
+ // C: Function types need to be compatible, not identical. This handles
// duplicate function decls like "void f(int); void f(enum X);" properly.
- if (Context.functionTypesAreCompatible(OldQType, NewQType))
+ if (!getLangOptions().CPlusPlus &&
+ Context.functionTypesAreCompatible(OldQType, NewQType)) {
return New;
+ }
// A function that has already been declared has been redeclared or defined
// with a different type- show appropriate diagnostic
@@ -295,7 +303,7 @@
PrevDiag = diag::err_previous_definition;
else if (Old->isImplicit())
PrevDiag = diag::err_previous_implicit_declaration;
- else
+ else
PrevDiag = diag::err_previous_declaration;
// TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
@@ -413,6 +421,49 @@
return New;
}
+/// CheckParmsForFunctionDef - Check that the parameters of the given
+/// function are appropriate for the definition of a function. This
+/// takes care of any checks that cannot be performed on the
+/// declaration itself, e.g., that the types of each of the function
+/// parameters are complete.
+bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
+ bool HasInvalidParm = false;
+ for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
+ ParmVarDecl *Param = FD->getParamDecl(p);
+
+ // C99 6.7.5.3p4: the parameters in a parameter type list in a
+ // function declarator that is part of a function definition of
+ // that function shall not have incomplete type.
+ if (Param->getType()->isIncompleteType() &&
+ !Param->isInvalidDecl()) {
+ Diag(Param->getLocation(), diag::err_typecheck_decl_incomplete_type,
+ Param->getType().getAsString());
+ Param->setInvalidDecl();
+ HasInvalidParm = true;
+ }
+ }
+
+ return HasInvalidParm;
+}
+
+/// CreateImplicitParameter - Creates an implicit function parameter
+/// in the scope S and with the given type. This routine is used, for
+/// example, to create the implicit "self" parameter in an Objective-C
+/// method.
+ParmVarDecl *
+Sema::CreateImplicitParameter(Scope *S, IdentifierInfo *Id,
+ SourceLocation IdLoc, QualType Type) {
+ ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, IdLoc, Id, Type,
+ VarDecl::None, 0, 0);
+ if (Id) {
+ New->setNext(Id->getFETokenInfo<ScopedDecl>());
+ Id->setFETokenInfo(New);
+ S->AddDecl(New);
+ }
+
+ return New;
+}
+
/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
/// no declarator (e.g. "struct foo;") is parsed.
Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) {
@@ -769,7 +820,38 @@
// Handle attributes.
HandleDeclAttributes(NewFD, D.getDeclSpec().getAttributes(),
D.getAttributes());
-
+
+ // Copy the parameter declarations from the declarator D to
+ // the function declaration NewFD, if they are available.
+ if (D.getNumTypeObjects() > 0 &&
+ D.getTypeObject(0).Fun.hasPrototype) {
+ DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
+
+ // Create Decl objects for each parameter, adding them to the
+ // FunctionDecl.
+ llvm::SmallVector<ParmVarDecl*, 16> Params;
+
+ // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
+ // function that takes no arguments, not a function that takes a
+ // single void argument. FIXME: Is this really the right place
+ // to check for this? C++ says that the parameter list (void) is
+ // the same as an empty parameter list, whereas the parameter
+ // list (T) (with T typedef'd to void) is not. For C++, this
+ // should be handled in the parser. Check C89 and C99 standards
+ // to see what the correct behavior is.
+ if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
+ FTI.ArgInfo[0].Param &&
+ !((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType().getCVRQualifiers() &&
+ ((ParmVarDecl*)FTI.ArgInfo[0].Param)->getType()->isVoidType()) {
+ // empty arg list, don't push any params.
+ } else {
+ for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
+ Params.push_back((ParmVarDecl *)FTI.ArgInfo[i].Param);
+ }
+
+ NewFD->setParams(&Params[0], Params.size());
+ }
+
// Merge the decl with the existing one if appropriate. Since C functions
// are in a flat namespace, make sure we consider decls in outer scopes.
if (PrevDecl) {
@@ -777,6 +859,10 @@
if (NewFD == 0) return 0;
}
New = NewFD;
+
+ // In C++, check default arguments now that we have merged decls.
+ if (getLangOptions().CPlusPlus)
+ CheckCXXDefaultArguments(NewFD);
} else {
if (R.getTypePtr()->isObjCInterfaceType()) {
Diag(D.getIdentifierLoc(), diag::err_statically_allocated_object,
@@ -982,20 +1068,47 @@
return NewGroup;
}
-// Called from Sema::ParseStartOfFunctionDef().
-ParmVarDecl *
-Sema::ActOnParamDeclarator(struct DeclaratorChunk::ParamInfo &PI,
- Scope *FnScope) {
- IdentifierInfo *II = PI.Ident;
+/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
+/// to introduce parameters into function prototype scope.
+Sema::DeclTy *
+Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
+ DeclSpec &DS = D.getDeclSpec();
+
+ // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
+ if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
+ DS.getStorageClassSpec() != DeclSpec::SCS_register) {
+ Diag(DS.getStorageClassSpecLoc(),
+ diag::err_invalid_storage_class_in_func_decl);
+ DS.ClearStorageClassSpecs();
+ }
+ if (DS.isThreadSpecified()) {
+ Diag(DS.getThreadSpecLoc(),
+ diag::err_invalid_storage_class_in_func_decl);
+ DS.ClearStorageClassSpecs();
+ }
+
+
+ // In this context, we *do not* check D.getInvalidType(). If the declarator
+ // type was invalid, GetTypeForDeclarator() still returns a "valid" type,
+ // though it will not reflect the user specified type.
+ QualType parmDeclType = GetTypeForDeclarator(D, S);
+
+ assert(!parmDeclType.isNull() && "GetTypeForDeclarator() returned null type");
+
// 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.
- if (/*Decl *PrevDecl = */LookupDecl(II, Decl::IDNS_Ordinary, FnScope)) {
-
+ IdentifierInfo *II = D.getIdentifier();
+ if (Decl *PrevDecl = LookupDecl(II, Decl::IDNS_Ordinary, S)) {
+ if (S->isDeclScope(PrevDecl)) {
+ Diag(D.getIdentifierLoc(), diag::err_param_redefinition,
+ dyn_cast<NamedDecl>(PrevDecl)->getName());
+
+ // Recover by removing the name
+ II = 0;
+ D.SetIdentifier(0, D.getIdentifierLoc());
+ }
}
-
- // FIXME: Handle storage class (auto, register). No declarator?
- // TODO: Chain to previous parameter with the prevdeclarator chain?
// Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
// Doing the promotion here has a win and a loss. The win is the type for
@@ -1014,29 +1127,29 @@
// FIXME: If a source translation tool needs to see the original type, then
// we need to consider storing both types (in ParmVarDecl)...
//
- QualType parmDeclType = QualType::getFromOpaquePtr(PI.TypeInfo);
if (parmDeclType->isArrayType()) {
// int x[restrict 4] -> int *restrict
parmDeclType = Context.getArrayDecayedType(parmDeclType);
} else if (parmDeclType->isFunctionType())
parmDeclType = Context.getPointerType(parmDeclType);
- ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, PI.IdentLoc, II,
- parmDeclType,
- VarDecl::None, 0);
+ ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext,
+ D.getIdentifierLoc(), II,
+ parmDeclType, VarDecl::None,
+ 0, 0);
- if (PI.InvalidType)
+ if (D.getInvalidType())
New->setInvalidDecl();
- // If this has an identifier, add it to the scope stack.
if (II) {
New->setNext(II->getFETokenInfo<ScopedDecl>());
II->setFETokenInfo(New);
- FnScope->AddDecl(New);
+ S->AddDecl(New);
}
- HandleDeclAttributes(New, PI.AttrList, 0);
+ HandleDeclAttributes(New, D.getAttributes(), 0);
return New;
+
}
Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
@@ -1044,17 +1157,23 @@
assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
"Not a function declarator!");
DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
-
+
// Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
// for a K&R function.
if (!FTI.hasPrototype) {
for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
- if (FTI.ArgInfo[i].TypeInfo == 0) {
+ if (FTI.ArgInfo[i].Param == 0) {
Diag(FTI.ArgInfo[i].IdentLoc, diag::ext_param_not_declared,
FTI.ArgInfo[i].Ident->getName());
// Implicitly declare the argument as type 'int' for lack of a better
// type.
- FTI.ArgInfo[i].TypeInfo = Context.IntTy.getAsOpaquePtr();
+ DeclSpec DS;
+ const char* PrevSpec; // unused
+ DS.SetTypeSpecType(DeclSpec::TST_int, FTI.ArgInfo[i].IdentLoc,
+ PrevSpec);
+ Declarator ParamD(DS, Declarator::KNRTypeListContext);
+ ParamD.SetIdentifier(FTI.ArgInfo[i].Ident, FTI.ArgInfo[i].IdentLoc);
+ FTI.ArgInfo[i].Param = ActOnParamDeclarator(FnBodyScope, ParamD);
}
}
@@ -1063,8 +1182,7 @@
if (FTI.NumArgs)
FTI.hasPrototype = true;
} else {
- // FIXME: Diagnose arguments without names in C.
-
+ // FIXME: Diagnose arguments without names in C.
}
Scope *GlobalScope = FnBodyScope->getParent();
@@ -1083,37 +1201,21 @@
FunctionDecl *FD = cast<FunctionDecl>(decl);
CurFunctionDecl = FD;
PushDeclContext(FD);
-
- // Create Decl objects for each parameter, adding them to the FunctionDecl.
- llvm::SmallVector<ParmVarDecl*, 16> Params;
-
- // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs function that takes
- // no arguments, not a function that takes a single void argument.
- if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
- !QualType::getFromOpaquePtr(FTI.ArgInfo[0].TypeInfo).getCVRQualifiers() &&
- QualType::getFromOpaquePtr(FTI.ArgInfo[0].TypeInfo)->isVoidType()) {
- // empty arg list, don't push any params.
- } else {
- for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
- ParmVarDecl *parmDecl;
-
- parmDecl = ActOnParamDeclarator(D.getTypeObject(0).Fun.ArgInfo[i],
- FnBodyScope);
- // C99 6.7.5.3p4: the parameters in a parameter type list in a function
- // declarator that is part of a function definition of that function
- // shall not have incomplete type.
- if (parmDecl->getType()->isIncompleteType() &&
- !parmDecl->isInvalidDecl()) {
- Diag(parmDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
- parmDecl->getType().getAsString());
- parmDecl->setInvalidDecl();
- }
- Params.push_back(parmDecl);
+
+ // Check the validity of our function parameters
+ CheckParmsForFunctionDef(FD);
+
+ // Introduce our parameters into the function scope
+ for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
+ ParmVarDecl *Param = FD->getParamDecl(p);
+ // If this has an identifier, add it to the scope stack.
+ if (IdentifierInfo *II = Param->getIdentifier()) {
+ Param->setNext(II->getFETokenInfo<ScopedDecl>());
+ II->setFETokenInfo(Param);
+ FnBodyScope->AddDecl(Param);
}
}
-
- FD->setParams(&Params[0], Params.size());
-
+
return FD;
}