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llvm-project/clang/Sema/SemaDecl.cpp

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//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for declarations.
//
//===----------------------------------------------------------------------===//
#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Builtins.h"
#include "clang/AST/Decl.h"
#include "clang/AST/Expr.h"
#include "clang/AST/Type.h"
#include "clang/AST/Attr.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Parse/Scope.h"
#include "clang/Lex/IdentifierTable.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/SmallSet.h"
using namespace llvm;
using namespace clang;
// C99: 6.7.5p3: Used by ParseDeclarator/ParseField to make sure we have
// a constant expression of type int with a value greater than zero.
bool Sema::isConstantArrayType(ArrayType *ary, SourceLocation loc) {
if (Expr *size = ary->getSize()) {
SourceLocation expLoc;
if (!size->isConstantExpr(&expLoc)) {
Diag(expLoc, diag::err_typecheck_illegal_vla);
return false;
}
if (!size->getType()->isIntegerType()) {
Diag(size->getLocStart(), diag::err_array_size_non_int,
size->getType().getAsString());
return false;
}
// We have a constant expression with an integer type, now make sure
// value greater than zero (C99 6.7.5.2p1).
// FIXME: evaluate constant expression.
}
return true;
}
Sema::DeclTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) const {
return dyn_cast_or_null<TypedefDecl>(II.getFETokenInfo<Decl>());
}
void Sema::PopScope(SourceLocation Loc, Scope *S) {
for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
I != E; ++I) {
Decl *D = static_cast<Decl*>(*I);
assert(D && "This decl didn't get pushed??");
IdentifierInfo *II = D->getIdentifier();
if (!II) continue;
// Unlink this decl from the identifier. Because the scope contains decls
// in an unordered collection, and because we have multiple identifier
// namespaces (e.g. tag, normal, label),the decl may not be the first entry.
if (II->getFETokenInfo<Decl>() == D) {
// Normal case, no multiple decls in different namespaces.
II->setFETokenInfo(D->getNext());
} else {
// Scan ahead. There are only three namespaces in C, so this loop can
// never execute more than 3 times.
Decl *SomeDecl = II->getFETokenInfo<Decl>();
while (SomeDecl->getNext() != D) {
SomeDecl = SomeDecl->getNext();
assert(SomeDecl && "Didn't find this decl on its identifier's chain!");
}
SomeDecl->setNext(D->getNext());
}
// This will have to be revisited for C++: there we want to nest stuff in
// namespace decls etc. Even for C, we might want a top-level translation
// unit decl or something.
if (!CurFunctionDecl)
continue;
// Chain this decl to the containing function, it now owns the memory for
// the decl.
D->setNext(CurFunctionDecl->getDeclChain());
CurFunctionDecl->setDeclChain(D);
}
}
/// LookupScopedDecl - Look up the inner-most declaration in the specified
/// namespace.
Decl *Sema::LookupScopedDecl(IdentifierInfo *II, unsigned NSI,
SourceLocation IdLoc, Scope *S) {
if (II == 0) return 0;
Decl::IdentifierNamespace NS = (Decl::IdentifierNamespace)NSI;
// Scan up the scope chain looking for a decl that matches this identifier
// that is in the appropriate namespace. This search should not take long, as
// shadowing of names is uncommon, and deep shadowing is extremely uncommon.
for (Decl *D = II->getFETokenInfo<Decl>(); D; D = D->getNext())
if (D->getIdentifierNamespace() == NS)
return D;
// If we didn't find a use of this identifier, and if the identifier
// corresponds to a compiler builtin, create the decl object for the builtin
// now, injecting it into translation unit scope, and return it.
if (NS == Decl::IDNS_Ordinary) {
// If this is a builtin on some other target, or if this builtin varies
// across targets (e.g. in type), emit a diagnostic and mark the translation
// unit non-portable for using it.
if (II->isNonPortableBuiltin()) {
// Only emit this diagnostic once for this builtin.
II->setNonPortableBuiltin(false);
Context.Target.DiagnoseNonPortability(IdLoc,
diag::port_target_builtin_use);
}
// If this is a builtin on this (or all) targets, create the decl.
if (unsigned BuiltinID = II->getBuiltinID())
return LazilyCreateBuiltin(II, BuiltinID, S);
}
return 0;
}
/// LazilyCreateBuiltin - The specified Builtin-ID was first used at file scope.
/// lazily create a decl for it.
Decl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned bid, Scope *S) {
Builtin::ID BID = (Builtin::ID)bid;
QualType R = Context.BuiltinInfo.GetBuiltinType(BID, Context);
FunctionDecl *New = new FunctionDecl(SourceLocation(), II, R);
// Find translation-unit scope to insert this function into.
while (S->getParent())
S = S->getParent();
S->AddDecl(New);
// Add this decl to the end of the identifier info.
if (Decl *LastDecl = II->getFETokenInfo<Decl>()) {
// Scan until we find the last (outermost) decl in the id chain.
while (LastDecl->getNext())
LastDecl = LastDecl->getNext();
// Insert before (outside) it.
LastDecl->setNext(New);
} else {
II->setFETokenInfo(New);
}
// Make sure clients iterating over decls see this.
LastInGroupList.push_back(New);
return New;
}
/// MergeTypeDefDecl - We just parsed a typedef '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.
///
TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
// Verify the old decl was also a typedef.
TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind,
New->getName());
Diag(OldD->getLocation(), diag::err_previous_definition);
return New;
}
// TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
// TODO: This is totally simplistic. It should handle merging functions
// together etc, merging extern int X; int X; ...
Diag(New->getLocation(), diag::err_redefinition, New->getName());
Diag(Old->getLocation(), diag::err_previous_definition);
return New;
}
/// 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.
///
FunctionDecl *Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) {
// Verify the old decl was also a function.
FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind,
New->getName());
Diag(OldD->getLocation(), diag::err_previous_definition);
return New;
}
// This is not right, but it's a start. If 'Old' is a function prototype with
// the same type as 'New', silently allow this. FIXME: We should link up decl
// objects here.
if (Old->getBody() == 0 &&
Old->getCanonicalType() == New->getCanonicalType()) {
return New;
}
// TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
// TODO: This is totally simplistic. It should handle merging functions
// together etc, merging extern int X; int X; ...
Diag(New->getLocation(), diag::err_redefinition, New->getName());
Diag(Old->getLocation(), diag::err_previous_definition);
return New;
}
/// MergeVarDecl - We just parsed a variable '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.
///
/// FIXME: Need to carefully consider tentative definition rules (C99 6.9.2p2).
/// For example, we incorrectly complain about i1, i4 from C99 6.9.2p4.
///
VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) {
// Verify the old decl was also a variable.
VarDecl *Old = dyn_cast<VarDecl>(OldD);
if (!Old) {
Diag(New->getLocation(), diag::err_redefinition_different_kind,
New->getName());
Diag(OldD->getLocation(), diag::err_previous_definition);
return New;
}
// Verify the types match.
if (Old->getCanonicalType() != New->getCanonicalType()) {
Diag(New->getLocation(), diag::err_redefinition, New->getName());
Diag(Old->getLocation(), diag::err_previous_definition);
return New;
}
// We've verified the types match, now check if Old is "extern".
if (Old->getStorageClass() != VarDecl::Extern) {
Diag(New->getLocation(), diag::err_redefinition, New->getName());
Diag(Old->getLocation(), diag::err_previous_definition);
}
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) {
// TODO: emit error on 'int;' or 'const enum foo;'.
// TODO: emit error on 'typedef int;'
// if (!DS.isMissingDeclaratorOk()) Diag(...);
return 0;
}
Action::DeclTy *
Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
DeclTy *LastInGroup) {
IdentifierInfo *II = D.getIdentifier();
// See if this is a redefinition of a variable in the same scope.
Decl *PrevDecl = LookupScopedDecl(II, Decl::IDNS_Ordinary,
D.getIdentifierLoc(), S);
if (!S->isDeclScope(PrevDecl))
PrevDecl = 0; // If in outer scope, it isn't the same thing.
Decl *New;
if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
TypedefDecl *NewTD = ParseTypedefDecl(S, D);
if (!NewTD) return 0;
// Merge the decl with the existing one if appropriate.
if (PrevDecl) {
NewTD = MergeTypeDefDecl(NewTD, PrevDecl);
if (NewTD == 0) return 0;
}
New = NewTD;
if (S->getParent() == 0) {
// C99 6.7.7p2: If a typedef name specifies a variably modified type
// then it shall have block scope.
if (ArrayType *ary = dyn_cast<ArrayType>(NewTD->getUnderlyingType())) {
if (!isConstantArrayType(ary, D.getIdentifierLoc()))
return 0;
}
}
} else if (D.isFunctionDeclarator()) {
QualType R = GetTypeForDeclarator(D, S);
if (R.isNull()) return 0; // FIXME: "auto func();" passes through...
FunctionDecl::StorageClass SC;
switch (D.getDeclSpec().getStorageClassSpec()) {
default: assert(0 && "Unknown storage class!");
case DeclSpec::SCS_auto:
case DeclSpec::SCS_register:
Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_func,
R.getAsString());
return 0;
case DeclSpec::SCS_unspecified: SC = FunctionDecl::None; break;
case DeclSpec::SCS_extern: SC = FunctionDecl::Extern; break;
case DeclSpec::SCS_static: SC = FunctionDecl::Static; break;
}
FunctionDecl *NewFD = new FunctionDecl(D.getIdentifierLoc(), II, R, SC);
// Merge the decl with the existing one if appropriate.
if (PrevDecl) {
NewFD = MergeFunctionDecl(NewFD, PrevDecl);
if (NewFD == 0) return 0;
}
New = NewFD;
} else {
QualType R = GetTypeForDeclarator(D, S);
if (R.isNull()) return 0;
VarDecl *NewVD;
VarDecl::StorageClass SC;
switch (D.getDeclSpec().getStorageClassSpec()) {
default: assert(0 && "Unknown storage class!");
case DeclSpec::SCS_unspecified: SC = VarDecl::None; break;
case DeclSpec::SCS_extern: SC = VarDecl::Extern; break;
case DeclSpec::SCS_static: SC = VarDecl::Static; break;
case DeclSpec::SCS_auto: SC = VarDecl::Auto; break;
case DeclSpec::SCS_register: SC = VarDecl::Register; break;
}
if (S->getParent() == 0) {
// File scope. C99 6.9.2p2: A declaration of an identifier for and
// object that has file scope without an initializer, and without a
// storage-class specifier or with the storage-class specifier "static",
// constitutes a tentative definition. Note: A tentative definition with
// external linkage is valid (C99 6.2.2p5).
if (!Init && SC == VarDecl::Static) {
// C99 6.9.2p3: If the declaration of an identifier for an object is
// a tentative definition and has internal linkage (C99 6.2.2p3), the
// declared type shall not be an incomplete type.
if (R->isIncompleteType()) {
Diag(D.getIdentifierLoc(), diag::err_typecheck_decl_incomplete_type,
R.getAsString());
return 0;
}
}
// C99 6.9p2: The storage-class specifiers auto and register shall not
// appear in the declaration specifiers in an external declaration.
if (SC == VarDecl::Auto || SC == VarDecl::Register) {
Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope,
R.getAsString());
return 0;
}
// C99 6.7.5.2p2: If an identifier is declared to be an object with
// static storage duration, it shall not have a variable length array.
if (ArrayType *ary = dyn_cast<ArrayType>(R)) {
if (!isConstantArrayType(ary, D.getIdentifierLoc()))
return 0;
}
NewVD = new FileVarDecl(D.getIdentifierLoc(), II, R, SC);
} else {
// Block scope. C99 6.7p7: If an identifier for an object is declared with
// no linkage (C99 6.2.2p6), the type for the object shall be complete...
if (SC != VarDecl::Extern) {
if (R->isIncompleteType()) {
Diag(D.getIdentifierLoc(), diag::err_typecheck_decl_incomplete_type,
R.getAsString());
return 0;
}
}
if (SC == VarDecl::Static) {
// C99 6.7.5.2p2: If an identifier is declared to be an object with
// static storage duration, it shall not have a variable length array.
if (ArrayType *ary = dyn_cast<ArrayType>(R)) {
if (!isConstantArrayType(ary, D.getIdentifierLoc()))
return 0;
}
}
NewVD = new BlockVarDecl(D.getIdentifierLoc(), II, R, SC);
}
// Merge the decl with the existing one if appropriate.
if (PrevDecl) {
NewVD = MergeVarDecl(NewVD, PrevDecl);
if (NewVD == 0) return 0;
}
New = NewVD;
}
// If this has an identifier, add it to the scope stack.
if (II) {
New->setNext(II->getFETokenInfo<Decl>());
II->setFETokenInfo(New);
S->AddDecl(New);
}
if (S->getParent() == 0)
AddTopLevelDecl(New, (Decl *)LastInGroup);
return New;
}
VarDecl *
Sema::ParseParamDeclarator(DeclaratorChunk &FTI, unsigned ArgNo,
Scope *FnScope) {
const DeclaratorChunk::ParamInfo &PI = FTI.Fun.ArgInfo[ArgNo];
IdentifierInfo *II = PI.Ident;
// 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 = LookupScopedDecl(II, Decl::IDNS_Ordinary,
PI.IdentLoc, FnScope)) {
}
// FIXME: Handle storage class (auto, register). No declarator?
VarDecl *New = new ParmVarDecl(PI.IdentLoc, II,
QualType::getFromOpaquePtr(PI.TypeInfo),
VarDecl::None);
// If this has an identifier, add it to the scope stack.
if (II) {
New->setNext(II->getFETokenInfo<Decl>());
II->setFETokenInfo(New);
FnScope->AddDecl(New);
}
return New;
}
Sema::DeclTy *Sema::ParseStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
assert(CurFunctionDecl == 0 && "Function parsing confused");
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) {
Diag(FTI.ArgInfo[i].IdentLoc, diag::err_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();
}
}
// Since this is a function definition, act as though we have information
// about the arguments.
FTI.hasPrototype = true;
} else {
// FIXME: Diagnose arguments without names in C.
}
Scope *GlobalScope = FnBodyScope->getParent();
FunctionDecl *FD =
static_cast<FunctionDecl*>(ParseDeclarator(GlobalScope, D, 0, 0));
CurFunctionDecl = FD;
// Create Decl objects for each parameter, adding them to the FunctionDecl.
SmallVector<VarDecl*, 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 &&
FTI.ArgInfo[0].TypeInfo == Context.VoidTy.getAsOpaquePtr()) {
// empty arg list, don't push any params.
} else {
for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
Params.push_back(ParseParamDeclarator(D.getTypeObject(0), i,FnBodyScope));
}
FD->setParams(&Params[0], Params.size());
return FD;
}
Sema::DeclTy *Sema::ParseFunctionDefBody(DeclTy *D, StmtTy *Body) {
FunctionDecl *FD = static_cast<FunctionDecl*>(D);
FD->setBody((Stmt*)Body);
assert(FD == CurFunctionDecl && "Function parsing confused");
CurFunctionDecl = 0;
// Verify and clean out per-function state.
// Check goto/label use.
for (DenseMap<IdentifierInfo*, LabelStmt*>::iterator I = LabelMap.begin(),
E = LabelMap.end(); I != E; ++I) {
// Verify that we have no forward references left. If so, there was a goto
// or address of a label taken, but no definition of it. Label fwd
// definitions are indicated with a null substmt.
if (I->second->getSubStmt() == 0) {
LabelStmt *L = I->second;
// Emit error.
Diag(L->getIdentLoc(), diag::err_undeclared_label_use, L->getName());
// At this point, we have gotos that use the bogus label. Stitch it into
// the function body so that they aren't leaked and that the AST is well
// formed.
L->setSubStmt(new NullStmt(L->getIdentLoc()));
cast<CompoundStmt>((Stmt*)Body)->push_back(L);
}
}
LabelMap.clear();
return FD;
}
/// ImplicitlyDefineFunction - An undeclared identifier was used in a function
/// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
Decl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
Scope *S) {
if (getLangOptions().C99) // Extension in C99.
Diag(Loc, diag::ext_implicit_function_decl, II.getName());
else // Legal in C90, but warn about it.
Diag(Loc, diag::warn_implicit_function_decl, II.getName());
// FIXME: handle stuff like:
// void foo() { extern float X(); }
// void bar() { X(); } <-- implicit decl for X in another scope.
// Set a Declarator for the implicit definition: int foo();
const char *Dummy;
DeclSpec DS;
bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy);
Error = Error; // Silence warning.
assert(!Error && "Error setting up implicit decl!");
Declarator D(DS, Declarator::BlockContext);
D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc));
D.SetIdentifier(&II, Loc);
// Find translation-unit scope to insert this function into.
while (S->getParent())
S = S->getParent();
return static_cast<Decl*>(ParseDeclarator(S, D, 0, 0));
}
TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D) {
assert(D.getIdentifier() && "Wrong callback for declspec withotu declarator");
QualType T = GetTypeForDeclarator(D, S);
if (T.isNull()) return 0;
// Scope manipulation handled by caller.
return new TypedefDecl(D.getIdentifierLoc(), D.getIdentifier(), T);
}
/// ParseTag - This is invoked when we see 'struct foo' or 'struct {'. In the
/// former case, Name will be non-null. In the later case, Name will be null.
/// TagType indicates what kind of tag this is. TK indicates whether this is a
/// reference/declaration/definition of a tag.
Sema::DeclTy *Sema::ParseTag(Scope *S, unsigned TagType, TagKind TK,
SourceLocation KWLoc, IdentifierInfo *Name,
SourceLocation NameLoc) {
// If this is a use of an existing tag, it must have a name.
assert((Name != 0 || TK == TK_Definition) &&
"Nameless record must be a definition!");
Decl::Kind Kind;
switch (TagType) {
default: assert(0 && "Unknown tag type!");
case DeclSpec::TST_struct: Kind = Decl::Struct; break;
case DeclSpec::TST_union: Kind = Decl::Union; break;
//case DeclSpec::TST_class: Kind = Decl::Class; break;
case DeclSpec::TST_enum: Kind = Decl::Enum; break;
}
// If this is a named struct, check to see if there was a previous forward
// declaration or definition.
if (TagDecl *PrevDecl =
dyn_cast_or_null<TagDecl>(LookupScopedDecl(Name, Decl::IDNS_Tag,
NameLoc, S))) {
// If this is a use of a previous tag, or if the tag is already declared in
// the same scope (so that the definition/declaration completes or
// rementions the tag), reuse the decl.
if (TK == TK_Reference || S->isDeclScope(PrevDecl)) {
// Make sure that this wasn't declared as an enum and now used as a struct
// or something similar.
if (PrevDecl->getKind() != Kind) {
Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName());
Diag(PrevDecl->getLocation(), diag::err_previous_use);
}
// If this is a use or a forward declaration, we're good.
if (TK != TK_Definition)
return PrevDecl;
// Diagnose attempts to redefine a tag.
if (PrevDecl->isDefinition()) {
Diag(NameLoc, diag::err_redefinition, Name->getName());
Diag(PrevDecl->getLocation(), diag::err_previous_definition);
// If this is a redefinition, recover by making this struct be
// anonymous, which will make any later references get the previous
// definition.
Name = 0;
} else {
// Okay, this is definition of a previously declared or referenced tag.
// Move the location of the decl to be the definition site.
PrevDecl->setLocation(NameLoc);
return PrevDecl;
}
}
// If we get here, this is a definition of a new struct type in a nested
// scope, e.g. "struct foo; void bar() { struct foo; }", just create a new
// type.
}
// If there is an identifier, use the location of the identifier as the
// location of the decl, otherwise use the location of the struct/union
// keyword.
SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
// Otherwise, if this is the first time we've seen this tag, create the decl.
TagDecl *New;
switch (Kind) {
default: assert(0 && "Unknown tag kind!");
case Decl::Enum:
New = new EnumDecl(Loc, Name);
// If this is an undefined enum, warn.
if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
break;
case Decl::Union:
case Decl::Struct:
case Decl::Class:
New = new RecordDecl(Kind, Loc, Name);
break;
}
// If this has an identifier, add it to the scope stack.
if (Name) {
New->setNext(Name->getFETokenInfo<Decl>());
Name->setFETokenInfo(New);
S->AddDecl(New);
}
return New;
}
/// ParseField - Each field of a struct/union/class is passed into this in order
/// to create a FieldDecl object for it.
Sema::DeclTy *Sema::ParseField(Scope *S, DeclTy *TagDecl,
SourceLocation DeclStart,
Declarator &D, ExprTy *BitfieldWidth) {
IdentifierInfo *II = D.getIdentifier();
Expr *BitWidth = (Expr*)BitfieldWidth;
SourceLocation Loc = DeclStart;
if (II) Loc = D.getIdentifierLoc();
// FIXME: Unnamed fields can be handled in various different ways, for
// example, unnamed unions inject all members into the struct namespace!
if (BitWidth) {
// TODO: Validate.
//printf("WARNING: BITFIELDS IGNORED!\n");
// 6.7.2.1p3
// 6.7.2.1p4
} else {
// Not a bitfield.
// validate II.
}
QualType T = GetTypeForDeclarator(D, S);
if (T.isNull()) return 0;
// C99 6.7.2.1p8: A member of a structure or union may have any type other
// than a variably modified type.
if (ArrayType *ary = dyn_cast<ArrayType>(T)) {
if (!isConstantArrayType(ary, Loc))
return 0;
}
return new FieldDecl(Loc, II, T);
}
void Sema::ParseRecordBody(SourceLocation RecLoc, DeclTy *RecDecl,
DeclTy **Fields, unsigned NumFields) {
RecordDecl *Record = cast<RecordDecl>(static_cast<Decl*>(RecDecl));
if (Record->isDefinition()) {
// Diagnose code like:
// struct S { struct S {} X; };
// We discover this when we complete the outer S. Reject and ignore the
// outer S.
Diag(Record->getLocation(), diag::err_nested_redefinition,
Record->getKindName());
Diag(RecLoc, diag::err_previous_definition);
return;
}
// Verify that all the fields are okay.
unsigned NumNamedMembers = 0;
SmallVector<FieldDecl*, 32> RecFields;
SmallSet<const IdentifierInfo*, 32> FieldIDs;
for (unsigned i = 0; i != NumFields; ++i) {
FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i]));
if (!FD) continue; // Already issued a diagnostic.
// Get the type for the field.
Type *FDTy = FD->getType().getCanonicalType().getTypePtr();
// C99 6.7.2.1p2 - A field may not be a function type.
if (isa<FunctionType>(FDTy)) {
Diag(FD->getLocation(), diag::err_field_declared_as_function,
FD->getName());
delete FD;
continue;
}
// C99 6.7.2.1p2 - A field may not be an incomplete type except...
if (FDTy->isIncompleteType()) {
if (i != NumFields-1 || // ... that the last member ...
Record->getKind() != Decl::Struct || // ... of a structure ...
!isa<ArrayType>(FDTy)) { //... may have incomplete array type.
Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
delete FD;
continue;
}
if (NumNamedMembers < 1) { //... must have more than named member ...
Diag(FD->getLocation(), diag::err_flexible_array_empty_struct,
FD->getName());
delete FD;
continue;
}
// Okay, we have a legal flexible array member at the end of the struct.
Record->setHasFlexibleArrayMember(true);
}
/// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the
/// field of another structure or the element of an array.
if (RecordType *FDTTy = dyn_cast<RecordType>(FDTy)) {
if (FDTTy->getDecl()->hasFlexibleArrayMember()) {
// If this is a member of a union, then entire union becomes "flexible".
if (Record->getKind() == Decl::Union) {
Record->setHasFlexibleArrayMember(true);
} else {
// If this is a struct/class and this is not the last element, reject
// it. Note that GCC supports variable sized arrays in the middle of
// structures.
if (i != NumFields-1) {
Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct,
FD->getName());
delete FD;
continue;
}
// We support flexible arrays at the end of structs in other structs
// as an extension.
Diag(FD->getLocation(), diag::ext_flexible_array_in_struct,
FD->getName());
Record->setHasFlexibleArrayMember(true);
}
}
}
// Keep track of the number of named members.
if (IdentifierInfo *II = FD->getIdentifier()) {
// Detect duplicate member names.
if (!FieldIDs.insert(II)) {
Diag(FD->getLocation(), diag::err_duplicate_member, II->getName());
// Find the previous decl.
SourceLocation PrevLoc;
for (unsigned i = 0, e = RecFields.size(); ; ++i) {
assert(i != e && "Didn't find previous def!");
if (RecFields[i]->getIdentifier() == II) {
PrevLoc = RecFields[i]->getLocation();
break;
}
}
Diag(PrevLoc, diag::err_previous_definition);
delete FD;
continue;
}
++NumNamedMembers;
}
// Remember good fields.
RecFields.push_back(FD);
}
// Okay, we successfully defined 'Record'.
Record->defineBody(&RecFields[0], RecFields.size());
}
Sema::DeclTy *Sema::ParseEnumConstant(Scope *S, DeclTy *EnumDeclX,
SourceLocation IdLoc, IdentifierInfo *Id,
SourceLocation EqualLoc, ExprTy *Val) {
EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
// Verify that there isn't already something declared with this name in this
// scope.
if (Decl *PrevDecl = LookupScopedDecl(Id, Decl::IDNS_Ordinary, IdLoc, S)) {
if (S->isDeclScope(PrevDecl)) {
if (isa<EnumConstantDecl>(PrevDecl))
Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName());
else
Diag(IdLoc, diag::err_redefinition, Id->getName());
Diag(PrevDecl->getLocation(), diag::err_previous_definition);
return 0;
}
}
SourceLocation expLoc;
// C99 6.7.2.2p2: Make sure we have an integer constant expression.
if (Val && !((Expr *)Val)->isIntegerConstantExpr(&expLoc)) {
Diag(expLoc, diag::err_enum_value_not_integer_constant_expr, Id->getName());
return 0;
}
QualType Ty = Context.getTagDeclType(TheEnumDecl);
EnumConstantDecl *New = new EnumConstantDecl(IdLoc, Id, Ty, (Expr *)Val);
// Register this decl in the current scope stack.
New->setNext(Id->getFETokenInfo<Decl>());
Id->setFETokenInfo(New);
S->AddDecl(New);
return New;
}
void Sema::ParseEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX,
DeclTy **Elements, unsigned NumElements) {
EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
assert(!Enum->isDefinition() && "Enum redefinitions can't reach here");
// Verify that all the values are okay.
SmallVector<EnumConstantDecl*, 32> Values;
for (unsigned i = 0; i != NumElements; ++i) {
EnumConstantDecl *ECD =
cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
if (!ECD) continue; // Already issued a diagnostic.
Values.push_back(ECD);
}
Enum->defineElements(&Values[0], Values.size());
}
void Sema::AddTopLevelDecl(Decl *current, Decl *last) {
if (!current) return;
// If this is a top-level decl that is chained to some other (e.g. int A,B,C;)
// remember this in the LastInGroupList list.
if (last) {
LastInGroupList.push_back((Decl*)last);
}
}
/// ParseAttribute GCC __attribute__
Sema::AttrTy *Sema::ParseAttribute(
IdentifierInfo *AttrName, SourceLocation AttrNameLoc, AttrTy *PrevAttr,
IdentifierInfo *ParmName, SourceLocation ParmNameLoc,
ExprTy **Args, unsigned NumArgs,
SourceLocation LParenLoc, SourceLocation RParenLoc) {
Attr *attrib = new Attr(AttrNameLoc, AttrName, ParmName, (Expr **)Args,
NumArgs);
if (PrevAttr)
// reuse Decl's "Next" pointer for chaining the attribute list
attrib->setNext(static_cast<Attr *>(PrevAttr));
return attrib;
}
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