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Refactor the uninitialized field visitor. Also moved the calls to the visitor 

later in the code so that the expressions will have addition processing first.
This catches a few additional cases of uninitialized uses of class fields.

llvm-svn: 190657
This commit is contained in:
Richard Trieu 2013-09-13 03:20:53 +00:00
parent 7ac694e87e
commit 1bc22c12cb
2 changed files with 109 additions and 56 deletions
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127
clang/lib/Sema/SemaDeclCXX.cpp
View File

@ -2073,6 +2073,7 @@ namespace {
: public EvaluatedExprVisitor<UninitializedFieldVisitor> {
Sema &S;
ValueDecl *VD;
bool isReferenceType;
public:
typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
UninitializedFieldVisitor(Sema &S, ValueDecl *VD) : Inherited(S.Context),
@ -2081,48 +2082,44 @@ namespace {
this->VD = IFD->getAnonField();
else
this->VD = VD;
isReferenceType = this->VD->getType()->isReferenceType();
}
void HandleExpr(Expr *E) {
if (!E) return;
void HandleMemberExpr(MemberExpr *ME) {
if (isa<EnumConstantDecl>(ME->getMemberDecl()))
return;
// Expressions like x(x) sometimes lack the surrounding expressions
// but need to be checked anyways.
HandleValue(E);
Visit(E);
// FieldME is the inner-most MemberExpr that is not an anonymous struct
// or union.
MemberExpr *FieldME = ME;
Expr *Base = ME;
while (isa<MemberExpr>(Base)) {
ME = cast<MemberExpr>(Base);
if (isa<VarDecl>(ME->getMemberDecl()))
return;
if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
if (!FD->isAnonymousStructOrUnion())
FieldME = ME;
Base = ME->getBase();
}
if (VD == FieldME->getMemberDecl() && isa<CXXThisExpr>(Base)) {
unsigned diag = VD->getType()->isReferenceType()
? diag::warn_reference_field_is_uninit
: diag::warn_field_is_uninit;
S.Diag(FieldME->getExprLoc(), diag) << VD;
}
}
void HandleValue(Expr *E) {
E = E->IgnoreParens();
if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
if (isa<EnumConstantDecl>(ME->getMemberDecl()))
return;
// FieldME is the inner-most MemberExpr that is not an anonymous struct
// or union.
MemberExpr *FieldME = ME;
Expr *Base = E;
while (isa<MemberExpr>(Base)) {
ME = cast<MemberExpr>(Base);
if (isa<VarDecl>(ME->getMemberDecl()))
return;
if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
if (!FD->isAnonymousStructOrUnion())
FieldME = ME;
Base = ME->getBase();
}
if (VD == FieldME->getMemberDecl() && isa<CXXThisExpr>(Base)) {
unsigned diag = VD->getType()->isReferenceType()
? diag::warn_reference_field_is_uninit
: diag::warn_field_is_uninit;
S.Diag(FieldME->getExprLoc(), diag) << VD;
}
HandleMemberExpr(ME);
return;
}
@ -2154,6 +2151,13 @@ namespace {
}
}
void VisitMemberExpr(MemberExpr *ME) {
if (isReferenceType)
HandleMemberExpr(ME);
Inherited::VisitMemberExpr(ME);
}
void VisitImplicitCastExpr(ImplicitCastExpr *E) {
if (E->getCastKind() == CK_LValueToRValue)
HandleValue(E->getSubExpr());
@ -2161,6 +2165,16 @@ namespace {
Inherited::VisitImplicitCastExpr(E);
}
void VisitCXXConstructExpr(CXXConstructExpr *E) {
if (E->getNumArgs() == 1)
if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(E->getArg(0)))
if (ICE->getCastKind() == CK_NoOp)
if (MemberExpr *ME = dyn_cast<MemberExpr>(ICE->getSubExpr()))
HandleMemberExpr(ME);
Inherited::VisitCXXConstructExpr(E);
}
void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
Expr *Callee = E->getCallee();
if (isa<MemberExpr>(Callee))
@ -2171,7 +2185,8 @@ namespace {
};
static void CheckInitExprContainsUninitializedFields(Sema &S, Expr *E,
ValueDecl *VD) {
UninitializedFieldVisitor(S, VD).HandleExpr(E);
if (E)
UninitializedFieldVisitor(S, VD).Visit(E);
}
} // namespace
@ -2198,11 +2213,6 @@ Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
return;
}
if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, InitLoc)
!= DiagnosticsEngine::Ignored) {
CheckInitExprContainsUninitializedFields(*this, InitExpr, FD);
}
ExprResult Init = InitExpr;
if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
InitializedEntity Entity = InitializedEntity::InitializeMember(FD);
@ -2228,6 +2238,11 @@ Sema::ActOnCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc,
InitExpr = Init.release();
if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, InitLoc)
!= DiagnosticsEngine::Ignored) {
CheckInitExprContainsUninitializedFields(*this, InitExpr, FD);
}
FD->setInClassInitializer(InitExpr);
}
@ -2555,10 +2570,6 @@ Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
if (Member->isInvalidDecl())
return true;
// Diagnose value-uses of fields to initialize themselves, e.g.
// foo(foo)
// where foo is not also a parameter to the constructor.
// TODO: implement -Wuninitialized and fold this into that framework.
MultiExprArg Args;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
@ -2569,19 +2580,6 @@ Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
Args = Init;
}
if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, IdLoc)
!= DiagnosticsEngine::Ignored)
for (unsigned i = 0, e = Args.size(); i != e; ++i)
// FIXME: Warn about the case when other fields are used before being
// initialized. For example, let this field be the i'th field. When
// initializing the i'th field, throw a warning if any of the >= i'th
// fields are used, as they are not yet initialized.
// Right now we are only handling the case where the i'th field uses
// itself in its initializer.
// Also need to take into account that some fields may be initialized by
// in-class initializers, see C++11 [class.base.init]p9.
CheckInitExprContainsUninitializedFields(*this, Args[i], Member);
SourceRange InitRange = Init->getSourceRange();
if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
@ -2621,6 +2619,23 @@ Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
Init = MemberInit.get();
}
// Diagnose value-uses of fields to initialize themselves, e.g.
// foo(foo)
// where foo is not also a parameter to the constructor.
// TODO: implement -Wuninitialized and fold this into that framework.
// FIXME: Warn about the case when other fields are used before being
// initialized. For example, let this field be the i'th field. When
// initializing the i'th field, throw a warning if any of the >= i'th
// fields are used, as they are not yet initialized.
// Right now we are only handling the case where the i'th field uses
// itself in its initializer.
// Also need to take into account that some fields may be initialized by
// in-class initializers, see C++11 [class.base.init]p9.
if (getDiagnostics().getDiagnosticLevel(diag::warn_field_is_uninit, IdLoc)
!= DiagnosticsEngine::Ignored) {
CheckInitExprContainsUninitializedFields(*this, Init, Member);
}
if (DirectMember) {
return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
InitRange.getBegin(), Init,

38
clang/test/SemaCXX/uninitialized.cpp
View File

@ -523,3 +523,41 @@ namespace lambdas {
A a2([&] { return a2.x; }); // ok
}
}
namespace record_fields {
struct A {
A() {}
A get();
static A num();
static A copy(A);
static A something(A&);
};
A ref(A&);
A const_ref(const A&);
A pointer(A*);
A normal(A);
struct B {
A a;
B(char (*)[1]) : a(a) {} // expected-warning {{uninitialized}}
B(char (*)[2]) : a(a.get()) {} // expected-warning {{uninitialized}}
B(char (*)[3]) : a(a.num()) {}
B(char (*)[4]) : a(a.copy(a)) {} // expected-warning {{uninitialized}}
B(char (*)[5]) : a(a.something(a)) {}
B(char (*)[6]) : a(ref(a)) {}
B(char (*)[7]) : a(const_ref(a)) {}
B(char (*)[8]) : a(pointer(&a)) {}
B(char (*)[9]) : a(normal(a)) {} // expected-warning {{uninitialized}}
A a1 = a1; // expected-warning {{uninitialized}}
A a2 = a2.get(); // expected-warning {{uninitialized}}
A a3 = a3.num();
A a4 = a4.copy(a4); // expected-warning {{uninitialized}}
A a5 = a5.something(a5);
A a6 = ref(a6);
A a7 = const_ref(a7);
A a8 = pointer(&a8);
A a9 = normal(a9); // expected-warning {{uninitialized}}
};
}