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Fix the following bug submitted by Ted Kremenek: 

void func() {
int xx = xx; // incorrectly diagnosed 'xx' as an undeclared identifier.
}

This smallish bug resulted in a largish fix. Here are some highlights:

- Needed to make sure ParseDeclarator is called *before* parsing any
initializer. Removed the "Init" argument to ParseDeclarator.
- Added AddInitializerToDecl() to the Action & Sema classes.
In Sema, this hook is responsible for validating the initializer and
installing it into the respective decl.
- Moved several semantic checks from ParseDeclarator() to 
FinalizeDeclaratorGroup(). Previously, this hook was only responsible for 
reversing a list. Now it plays a much larger semantic role. 

All of the above changes ended up simplifying ParseDeclarator(), which
is goodness...

llvm-svn: 41877
This commit is contained in:
Steve Naroff 2007-09-12 14:07:44 +00:00
parent 100410af13
commit 6109140b00
7 changed files with 127 additions and 102 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
clang/Driver/PrintParserCallbacks.cpp
View File

@ -25,7 +25,7 @@ namespace {
/// ParseDeclarator - This callback is invoked when a declarator is parsed
/// and 'Init' specifies the initializer if any. This is for things like:
/// "int X = 4" or "typedef int foo".
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D,
DeclTy *LastInGroup) {
std::cout << "ParseDeclarator ";
if (IdentifierInfo *II = D.getIdentifier()) {
@ -36,7 +36,7 @@ namespace {
std::cout << "\n";
// Pass up to EmptyActions so that the symbol table is maintained right.
return MinimalAction::ParseDeclarator(S, D, Init, LastInGroup);
return MinimalAction::ParseDeclarator(S, D, LastInGroup);
}
/// PopScope - This callback is called immediately before the specified scope

3
clang/Parse/MinimalAction.cpp
View File

@ -43,8 +43,7 @@ MinimalAction::isTypeName(const IdentifierInfo &II, Scope *S) const {
/// IdentifierInfo::FETokenInfo field to keep track of this fact, until S is
/// popped.
Action::DeclTy *
MinimalAction::ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
DeclTy *LastInGroup) {
MinimalAction::ParseDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup) {
IdentifierInfo *II = D.getIdentifier();
// If there is no identifier associated with this declarator, bail out.

12
clang/Parse/ParseDecl.cpp
View File

@ -262,7 +262,11 @@ ParseInitDeclaratorListAfterFirstDeclarator(Declarator &D) {
// If attributes are present, parse them.
if (Tok.getKind() == tok::kw___attribute)
D.AddAttributes(ParseAttributes());
// Inform the current actions module that we just parsed this declarator.
// FIXME: pass asm & attributes.
LastDeclInGroup = Actions.ParseDeclarator(CurScope, D, LastDeclInGroup);
// Parse declarator '=' initializer.
ExprResult Init;
if (Tok.getKind() == tok::equal) {
@ -272,13 +276,9 @@ ParseInitDeclaratorListAfterFirstDeclarator(Declarator &D) {
SkipUntil(tok::semi);
return 0;
}
Actions.AddInitializerToDecl(LastDeclInGroup, Init.Val);
}
// Inform the current actions module that we just parsed this declarator.
// FIXME: pass asm & attributes.
LastDeclInGroup = Actions.ParseDeclarator(CurScope, D, Init.Val,
LastDeclInGroup);
// If we don't have a comma, it is either the end of the list (a ';') or an
// error, bail out.
if (Tok.getKind() != tok::comma)

2
clang/Parse/Parser.cpp
View File

@ -242,7 +242,7 @@ void Parser::Initialize() {
Declarator D(DS, Declarator::FileContext);
D.SetIdentifier(PP.getIdentifierInfo("__builtin_va_list"),SourceLocation());
Actions.ParseDeclarator(CurScope, D, 0, 0);
Actions.ParseDeclarator(CurScope, D, 0);
}
if (Tok.getKind() == tok::eof &&

6
clang/Sema/Sema.h
View File

@ -137,8 +137,8 @@ private:
// Symbol table / Decl tracking callbacks: SemaDecl.cpp.
//
virtual DeclTy *isTypeName(const IdentifierInfo &II, Scope *S) const;
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
DeclTy *LastInGroup);
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup);
void AddInitializerToDecl(DeclTy *dcl, ExprTy *init);
virtual DeclTy *FinalizeDeclaratorGroup(Scope *S, DeclTy *Group);
virtual DeclTy *ParseStartOfFunctionDef(Scope *S, Declarator &D);
@ -361,7 +361,7 @@ public:
virtual void ObjcAddMethodsToClass(DeclTy *ClassDecl,
DeclTy **allMethods, unsigned allNum);
virtual void ObjcAddInstanceVariable(DeclTy *ClassDec, DeclTy *Ivars,
virtual void ObjcAddInstanceVariable(DeclTy *ClassDec, DeclTy *Ivar,
tok::ObjCKeywordKind visibility);
private:
// UsualUnaryConversions - promotes integers (C99 6.3.1.1p2) and converts

184
clang/Sema/SemaDecl.cpp
View File

@ -427,10 +427,8 @@ bool Sema::CheckInitializer(Expr *&Init, QualType &DeclType, bool isStatic) {
}
Sema::DeclTy *
Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
DeclTy *lastDeclarator) {
Sema::ParseDeclarator(Scope *S, Declarator &D, DeclTy *lastDeclarator) {
Decl *LastDeclarator = (Decl*)lastDeclarator;
Expr *Init = static_cast<Expr*>(init);
IdentifierInfo *II = D.getIdentifier();
// All of these full declarators require an identifier. If it doesn't have
@ -457,7 +455,6 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
bool InvalidDecl = false;
if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
assert(Init == 0 && "Can't have initializer for a typedef!");
TypedefDecl *NewTD = ParseTypedefDecl(S, D, LastDeclarator);
if (!NewTD) return 0;
@ -481,8 +478,6 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
}
}
} else if (D.isFunctionDeclarator()) {
assert(Init == 0 && "Can't have an initializer for a functiondecl!");
QualType R = GetTypeForDeclarator(D, S);
assert(!R.isNull() && "GetTypeForDeclarator() returned null type");
@ -525,27 +520,6 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
case DeclSpec::SCS_register: SC = VarDecl::Register; break;
}
if (S->getParent() == 0) {
if (Init) {
if (SC == VarDecl::Extern)
Diag(D.getIdentifierLoc(), diag::warn_extern_init);
if (!D.getInvalidType())
CheckInitializer(Init, R, true);
}
// 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());
InvalidDecl = true;
}
}
// 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) {
@ -553,53 +527,8 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
R.getAsString());
InvalidDecl = true;
}
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 (const VariableArrayType *VLA = R->getAsVariableArrayType()) {
Expr *Size = VLA->getSizeExpr();
if (Size || (!Size && !Init)) {
// FIXME: Since we don't support initializers yet, we only emit this
// error when we don't have an initializer. Once initializers are
// implemented, the VLA will change to a CLA.
Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla);
InvalidDecl = true;
}
}
}
NewVD = new FileVarDecl(D.getIdentifierLoc(), II, R, SC, LastDeclarator);
} else {
if (Init) {
if (SC == VarDecl::Extern) { // C99 6.7.8p5
Diag(D.getIdentifierLoc(), diag::err_block_extern_cant_init);
InvalidDecl = true;
} else if (!D.getInvalidType()) {
CheckInitializer(Init, R, SC == VarDecl::Static);
}
}
// 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());
InvalidDecl = true;
}
}
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 (const VariableArrayType *VLA = R->getAsVariableArrayType()) {
Expr *Size = VLA->getSizeExpr();
if (Size || (!Size && !Init)) {
// FIXME: Since we don't support initializers yet, we only emit this
// error when we don't have an initializer. Once initializers are
// implemented, the VLA will change to a CLA.
Diag(D.getIdentifierLoc(), diag::err_typecheck_illegal_vla);
InvalidDecl = true;
}
}
}
NewVD = new BlockVarDecl(D.getIdentifierLoc(), II, R, SC, LastDeclarator);
}
// Handle attributes prior to checking for duplicates in MergeVarDecl
@ -611,9 +540,6 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
NewVD = MergeVarDecl(NewVD, PrevDecl);
if (NewVD == 0) return 0;
}
if (Init) { // FIXME: This will likely move up above...for now, it stays.
NewVD->setInit(Init);
}
New = NewVD;
}
@ -634,18 +560,110 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
return New;
}
void Sema::AddInitializerToDecl(DeclTy *dcl, ExprTy *init) {
VarDecl *Dcl = dyn_cast<VarDecl>(static_cast<Decl *>(dcl));
Expr *Init = static_cast<Expr *>(init);
assert((Dcl && Init) && "missing decl or initializer");
// FIXME: moved these directly from ParseDeclarator(). Need to convert
// asserts to actual error diagnostics!
if (isa<FunctionDecl>(Dcl))
assert(0 && "Can't have an initializer for a functiondecl!");
if (isa<TypedefDecl>(Dcl))
assert(0 && "Can't have an initializer for a typedef!");
// Get the decls type and save a reference for later, since
// CheckInitializer may change it.
QualType DclT = Dcl->getType(), SavT = DclT;
if (BlockVarDecl *BVD = dyn_cast<BlockVarDecl>(Dcl)) {
VarDecl::StorageClass SC = BVD->getStorageClass();
if (SC == VarDecl::Extern) { // C99 6.7.8p5
Diag(Dcl->getLocation(), diag::err_block_extern_cant_init);
BVD->setInvalidDecl();
} else if (!BVD->isInvalidDecl()) {
CheckInitializer(Init, DclT, SC == VarDecl::Static);
}
} else if (FileVarDecl *FVD = dyn_cast<FileVarDecl>(Dcl)) {
if (FVD->getStorageClass() == VarDecl::Extern)
Diag(Dcl->getLocation(), diag::warn_extern_init);
if (!FVD->isInvalidDecl())
CheckInitializer(Init, DclT, true);
}
// If the type changed, it means we had an incomplete type that was
// completed by the initializer. For example:
// int ary[] = { 1, 3, 5 };
// "ary" transitions from a VariableArrayType to a ConstantArrayType.
if (!Dcl->isInvalidDecl() && (DclT != SavT))
Dcl->setType(DclT);
// Attach the initializer to the decl.
Dcl->setInit(Init);
return;
}
/// The declarators are chained together backwards, reverse the list.
Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) {
// Often we have single declarators, handle them quickly.
Decl *Group = static_cast<Decl*>(group);
if (Group == 0 || Group->getNextDeclarator() == 0) return Group;
if (Group == 0)
return 0;
Decl *NewGroup = 0;
while (Group) {
Decl *Next = Group->getNextDeclarator();
Group->setNextDeclarator(NewGroup);
if (Group->getNextDeclarator() == 0)
NewGroup = Group;
Group = Next;
else { // reverse the list.
while (Group) {
Decl *Next = Group->getNextDeclarator();
Group->setNextDeclarator(NewGroup);
NewGroup = Group;
Group = Next;
}
}
// Perform semantic analysis that depends on having fully processed both
// the declarator and initializer.
for (Decl *ID = NewGroup; ID; ID = ID->getNextDeclarator()) {
VarDecl *IDecl = dyn_cast<VarDecl>(ID);
if (!IDecl)
continue;
FileVarDecl *FVD = dyn_cast<FileVarDecl>(IDecl);
BlockVarDecl *BVD = dyn_cast<BlockVarDecl>(IDecl);
QualType T = IDecl->getType();
// 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 ((FVD || BVD) && IDecl->getStorageClass() == VarDecl::Static) {
if (const VariableArrayType *VLA = T->getAsVariableArrayType()) {
if (VLA->getSizeExpr()) {
Diag(IDecl->getLocation(), diag::err_typecheck_illegal_vla);
IDecl->setInvalidDecl();
}
}
}
// 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 (BVD && IDecl->getStorageClass() != VarDecl::Extern) {
if (T->isIncompleteType()) {
Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
T.getAsString());
IDecl->setInvalidDecl();
}
}
// 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 (FVD && !FVD->getInit() && FVD->getStorageClass() == 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 (T->isIncompleteType()) {
Diag(IDecl->getLocation(), diag::err_typecheck_decl_incomplete_type,
T.getAsString());
IDecl->setInvalidDecl();
}
}
}
return NewGroup;
}
@ -737,7 +755,7 @@ Sema::DeclTy *Sema::ParseStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
Scope *GlobalScope = FnBodyScope->getParent();
FunctionDecl *FD =
static_cast<FunctionDecl*>(ParseDeclarator(GlobalScope, D, 0, 0));
static_cast<FunctionDecl*>(ParseDeclarator(GlobalScope, D, 0));
CurFunctionDecl = FD;
// Create Decl objects for each parameter, adding them to the FunctionDecl.
@ -820,7 +838,7 @@ Decl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
while (S->getParent())
S = S->getParent();
return static_cast<Decl*>(ParseDeclarator(S, D, 0, 0));
return static_cast<Decl*>(ParseDeclarator(S, D, 0));
}

18
clang/include/clang/Parse/Action.h
View File

@ -100,11 +100,20 @@ public:
/// LastInGroup is non-null for cases where one declspec has multiple
/// declarators on it. For example in 'int A, B', ParseDeclarator will be
/// called with LastInGroup=A when invoked for B.
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D,
ExprTy *Init, DeclTy *LastInGroup) {
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D,DeclTy *LastInGroup) {
return 0;
}
/// AddInitializerToDecl - This action is called immediately after
/// ParseDeclarator (when an initializer is present). The code is factored
/// this way to make sure we are able to handle the following:
/// void func() { int xx = xx; }
/// This allows ParseDeclarator to register "xx" prior to parsing the
/// initializer. The declaration above should still result in a warning,
/// since the reference to "xx" is uninitialized.
virtual void AddInitializerToDecl(DeclTy *Dcl, ExprTy *Init) {
return;
}
/// FinalizeDeclaratorGroup - After a sequence of declarators are parsed, this
/// gives the actions implementation a chance to process the group as a whole.
virtual DeclTy *FinalizeDeclaratorGroup(Scope *S, DeclTy *Group) {
@ -116,7 +125,7 @@ public:
/// information about formal arguments that are part of this function.
virtual DeclTy *ParseStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
// Default to ParseDeclarator.
return ParseDeclarator(FnBodyScope, D, 0, 0);
return ParseDeclarator(FnBodyScope, D, 0);
}
/// ParseFunctionDefBody - This is called when a function body has completed
@ -495,8 +504,7 @@ public:
/// ParseDeclarator - If this is a typedef declarator, we modify the
/// IdentifierInfo::FETokenInfo field to keep track of this fact, until S is
/// popped.
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
DeclTy *LastInGroup);
virtual DeclTy *ParseDeclarator(Scope *S, Declarator &D, DeclTy *LastInGroup);
/// PopScope - When a scope is popped, if any typedefs are now out-of-scope,
/// they are removed from the IdentifierInfo::FETokenInfo field.