[patch] Implementing -Wunused-local-typedefs
Nico Weber
thakis at chromium.org
Fri Sep 5 16:44:10 PDT 2014
On Fri, Sep 5, 2014 at 2:44 PM, Richard Smith <richard at metafoo.co.uk> wrote:
> Thanks, this is looking really good.
>
> + if (Diags.isIgnored(diag::warn_unused_local_typedef, SourceLocation()))
> + return;
>
> It would seem better to consider the diagnostic state at the point where
> the typedef is declared. (Maybe check this when adding typedefs to the set
> rather than when diagnosing?)
>
Great catch. -Wunused-private-fields probably gets this wrong too. I added
a test for this (see the very bottom of warn-unused-local-typedef.cpp, and
the pragma diagnostic push/pop). The test sadly showed that adding when
adding the typedefs is wrong too: For template instantiations, the
instantiation is done at end-of-file, but a pragma diag at end of file
shouldn't disable warnings in templates that physically are further up. So
I just removed this check.
> + // Warnigns emitted in ActOnEndOfTranslationUnit() should be emitted
> for
>
> Typo 'Warnigns'.
>
Doen.
> + // Except for labels, we only care about unused decls that are local to
> + // functions.
> + bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
> + if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
> + WithinFunction =
> + WithinFunction || (R->isLocalClass() && !R->isDependentType());
>
> Why are dependent local classes skipped here? I'd like at least a comment
> to explain this so future readers aren't surprised :)
>
I added a short comment. This is covered by my tests, so removing it does
make something fail.
(SemaTemplateInstantiateDecl.cpp's Sema::BuildVariableInstantiation() calls
this method for instantiated fields, so the warnings are deferred until
after instantiation.)
>
> + for (auto *TmpD : D->decls()) {
> + if (const auto* T = dyn_cast<TypedefNameDecl>(TmpD))
> + DiagnoseUnusedDecl(T);
> + else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
>
> '*' on the right, please.
>
Done.
>
> + if (auto* TD = dyn_cast<TypedefNameDecl>(D)) {
> + // typedefs can be referenced later on, so the diagnostics are emitted
> + // at end-of-translation-unit.
>
> Likewise.
>
Done.
>
> +void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
> + if (D->getTypeForDecl()->isDependentType())
> + return;
> +
> + for (auto *TmpD : D->decls()) {
> + if (const auto* T = dyn_cast<TypedefNameDecl>(TmpD))
> + DiagnoseUnusedDecl(T);
> + else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
> + DiagnoseUnusedNestedTypedefs(R);
> + }
> +}
> [...]
> - if (!S->hasUnrecoverableErrorOccurred())
> + if (!S->hasUnrecoverableErrorOccurred()) {
> DiagnoseUnusedDecl(D);
> + if (const auto *RD = dyn_cast<RecordDecl>(D))
> + DiagnoseUnusedNestedTypedefs(RD);
> + }
>
> Would it make sense for DiagnoseUnusedDecl to do the recursive walk over
> child decls itself?
>
Doesn't matter too much either way I guess? Left it as is for now.
>
> +/// In a function like
> +/// auto f() {
> +/// struct S { typedef int a; };
> +/// return S;
> +/// }
>
> Should be 'return S();' or similar here.
>
Done.
> +/// others. Pretend that all local typedefs are always references, to not
> warn
>
> Typo 'references'.
>
Done.
> +class LocalTypedefNameReferencer
> + : public RecursiveASTVisitor<LocalTypedefNameReferencer> {
> +public:
> + LocalTypedefNameReferencer(Sema &S) : S(S) {}
> + bool VisitRecordType(const RecordType *RT);
> +private:
> + Sema &S;
> +};
>
> I think you'll also need to handle MemberPointerType here; the `Class` in
> `T Class::*` is just modeled as a CXXRecordDecl, not a RecordType.
>
I added the (slightly contrived :-) ) test you showed me, it seems to pass
as-is.
> + if (T->getAccess() != AS_private)
>
> You should also check if the class has any friends; if so, they might use
> the member.
>
Good point. Done, added a test for this.
> + }
> else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
>
> No newline between } and else.
>
Done.
> + // Build a record containing all of the
> UnusedLocalTypedefNameCandidates.
> + RecordData UnusedLocalTypedefNameCandidates;
> + for (const TypedefNameDecl *TD :
> SemaRef.UnusedLocalTypedefNameCandidates)
> + AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
>
> Maybe wrap this in a `if (!isModule)`
>
UnusedLocalTypedefNameCandidates should've been clear()ed for modules at
this point I think, so should be fine as is.
> + // FIXME: typedef that's only used in a constexpr
>
> Do you mean "in a constant expression"? constexpr is an adjective, not a
> noun.
>
Done (by fixing the FIXME).
Thanks for the thorough review!
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Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td (revision 217285)
+++ include/clang/Basic/DiagnosticGroups.td (working copy)
@@ -402,6 +402,7 @@
def UnusedConstVariable : DiagGroup<"unused-const-variable">;
def UnusedVariable : DiagGroup<"unused-variable",
[UnusedConstVariable]>;
+def UnusedLocalTypedef : DiagGroup<"unused-local-typedef">;
def UnusedPropertyIvar : DiagGroup<"unused-property-ivar">;
def UsedButMarkedUnused : DiagGroup<"used-but-marked-unused">;
def UserDefinedLiterals : DiagGroup<"user-defined-literals">;
@@ -526,7 +527,7 @@
[UnusedArgument, UnusedFunction, UnusedLabel,
// UnusedParameter, (matches GCC's behavior)
// UnusedMemberFunction, (clean-up llvm before enabling)
- UnusedPrivateField,
+ UnusedPrivateField, UnusedLocalTypedef,
UnusedValue, UnusedVariable, UnusedPropertyIvar]>,
DiagCategory<"Unused Entity Issue">;
@@ -622,6 +623,8 @@
[IntConversion]>; // -Wint-conversions = -Wint-conversion
def : DiagGroup<"vector-conversions",
[VectorConversion]>; // -Wvector-conversions = -Wvector-conversion
+def : DiagGroup<"unused-local-typedefs", [UnusedLocalTypedef]>;
+ // -Wunused-local-typedefs = -Wunused-local-typedef
// A warning group for warnings that we want to have on by default in clang,
// but which aren't on by default in GCC.
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td (revision 217285)
+++ include/clang/Basic/DiagnosticSemaKinds.td (working copy)
@@ -175,6 +175,9 @@
InGroup<UnusedParameter>, DefaultIgnore;
def warn_unused_variable : Warning<"unused variable %0">,
InGroup<UnusedVariable>, DefaultIgnore;
+def warn_unused_local_typedef : Warning<
+ "unused %select{typedef|type alias}0 %1">,
+ InGroup<UnusedLocalTypedef>, DefaultIgnore;
def warn_unused_property_backing_ivar :
Warning<"ivar %0 which backs the property is not "
"referenced in this property's accessor">,
Index: include/clang/Sema/ExternalSemaSource.h
===================================================================
--- include/clang/Sema/ExternalSemaSource.h (revision 217285)
+++ include/clang/Sema/ExternalSemaSource.h (working copy)
@@ -20,6 +20,10 @@
#include "llvm/ADT/MapVector.h"
#include <utility>
+namespace llvm {
+template <class T, unsigned n> class SmallSetVector;
+}
+
namespace clang {
class CXXConstructorDecl;
@@ -132,6 +136,15 @@
/// introduce the same declarations repeatedly.
virtual void ReadDynamicClasses(SmallVectorImpl<CXXRecordDecl *> &Decls) {}
+ /// \brief Read the set of potentially unused typedefs known to the source.
+ ///
+ /// The external source should append its own potentially unused local
+ /// typedefs to the given vector of declarations. Note that this routine may
+ /// be invoked multiple times; the external source should take care not to
+ /// introduce the same declarations repeatedly.
+ virtual void ReadUnusedLocalTypedefNameCandidates(
+ llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) {};
+
/// \brief Read the set of locally-scoped external declarations known to the
/// external Sema source.
///
Index: include/clang/Sema/MultiplexExternalSemaSource.h
===================================================================
--- include/clang/Sema/MultiplexExternalSemaSource.h (revision 217285)
+++ include/clang/Sema/MultiplexExternalSemaSource.h (working copy)
@@ -282,6 +282,15 @@
/// introduce the same declarations repeatedly.
void ReadDynamicClasses(SmallVectorImpl<CXXRecordDecl*> &Decls) override;
+ /// \brief Read the set of potentially unused typedefs known to the source.
+ ///
+ /// The external source should append its own potentially unused local
+ /// typedefs to the given vector of declarations. Note that this routine may
+ /// be invoked multiple times; the external source should take care not to
+ /// introduce the same declarations repeatedly.
+ void ReadUnusedLocalTypedefNameCandidates(
+ llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) override;
+
/// \brief Read the set of locally-scoped extern "C" declarations known to the
/// external Sema source.
///
Index: include/clang/Sema/Sema.h
===================================================================
--- include/clang/Sema/Sema.h (revision 217285)
+++ include/clang/Sema/Sema.h (working copy)
@@ -389,6 +389,10 @@
/// \brief Set containing all declared private fields that are not used.
NamedDeclSetType UnusedPrivateFields;
+ /// \brief Set containing all typedefs that are likely unused.
+ llvm::SmallSetVector<const TypedefNameDecl *, 4>
+ UnusedLocalTypedefNameCandidates;
+
typedef llvm::SmallPtrSet<const CXXRecordDecl*, 8> RecordDeclSetTy;
/// PureVirtualClassDiagSet - a set of class declarations which we have
@@ -1048,6 +1052,8 @@
/// \brief Retrieve the module loader associated with the preprocessor.
ModuleLoader &getModuleLoader() const;
+ void emitAndClearUnusedLocalTypedefWarnings();
+
void ActOnEndOfTranslationUnit();
void CheckDelegatingCtorCycles();
@@ -3209,6 +3215,7 @@
/// DiagnoseUnusedExprResult - If the statement passed in is an expression
/// whose result is unused, warn.
void DiagnoseUnusedExprResult(const Stmt *S);
+ void DiagnoseUnusedNestedTypedefs(const RecordDecl *D);
void DiagnoseUnusedDecl(const NamedDecl *ND);
/// Emit \p DiagID if statement located on \p StmtLoc has a suspicious null
Index: include/clang/Serialization/ASTBitCodes.h
===================================================================
--- include/clang/Serialization/ASTBitCodes.h (revision 217285)
+++ include/clang/Serialization/ASTBitCodes.h (working copy)
@@ -545,7 +545,10 @@
LATE_PARSED_TEMPLATE = 50,
/// \brief Record code for \#pragma optimize options.
- OPTIMIZE_PRAGMA_OPTIONS = 51
+ OPTIMIZE_PRAGMA_OPTIONS = 51,
+
+ /// \brief Record code for potentially unused local typedef names.
+ UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES = 52,
};
/// \brief Record types used within a source manager block.
Index: include/clang/Serialization/ASTReader.h
===================================================================
--- include/clang/Serialization/ASTReader.h (revision 217285)
+++ include/clang/Serialization/ASTReader.h (working copy)
@@ -759,6 +759,11 @@
/// at the end of the TU, in which case it directs CodeGen to emit the VTable.
SmallVector<uint64_t, 16> DynamicClasses;
+ /// \brief The IDs of all potentially unused typedef names in the chain.
+ ///
+ /// Sema tracks these to emit warnings.
+ SmallVector<uint64_t, 16> UnusedLocalTypedefNameCandidates;
+
/// \brief The IDs of the declarations Sema stores directly.
///
/// Sema tracks a few important decls, such as namespace std, directly.
@@ -1789,6 +1794,9 @@
void ReadDynamicClasses(SmallVectorImpl<CXXRecordDecl *> &Decls) override;
+ void ReadUnusedLocalTypedefNameCandidates(
+ llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) override;
+
void ReadLocallyScopedExternCDecls(
SmallVectorImpl<NamedDecl *> &Decls) override;
Index: lib/Sema/MultiplexExternalSemaSource.cpp
===================================================================
--- lib/Sema/MultiplexExternalSemaSource.cpp (revision 217285)
+++ lib/Sema/MultiplexExternalSemaSource.cpp (working copy)
@@ -242,6 +242,12 @@
Sources[i]->ReadDynamicClasses(Decls);
}
+void MultiplexExternalSemaSource::ReadUnusedLocalTypedefNameCandidates(
+ llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) {
+ for(size_t i = 0; i < Sources.size(); ++i)
+ Sources[i]->ReadUnusedLocalTypedefNameCandidates(Decls);
+}
+
void MultiplexExternalSemaSource::ReadLocallyScopedExternCDecls(
SmallVectorImpl<NamedDecl*> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Index: lib/Sema/Sema.cpp
===================================================================
--- lib/Sema/Sema.cpp (revision 217285)
+++ lib/Sema/Sema.cpp (working copy)
@@ -597,6 +597,19 @@
return Complete;
}
+void Sema::emitAndClearUnusedLocalTypedefWarnings() {
+ if (ExternalSource)
+ ExternalSource->ReadUnusedLocalTypedefNameCandidates(
+ UnusedLocalTypedefNameCandidates);
+ for (const TypedefNameDecl *TD : UnusedLocalTypedefNameCandidates) {
+ if (TD->isReferenced())
+ continue;
+ Diag(TD->getLocation(), diag::warn_unused_local_typedef)
+ << isa<TypeAliasDecl>(TD) << TD->getDeclName();
+ }
+ UnusedLocalTypedefNameCandidates.clear();
+}
+
/// ActOnEndOfTranslationUnit - This is called at the very end of the
/// translation unit when EOF is reached and all but the top-level scope is
/// popped.
@@ -719,6 +732,10 @@
}
}
+ // Warnings emitted in ActOnEndOfTranslationUnit() should be emitted for
+ // modules when they are built, not every time they are used.
+ emitAndClearUnusedLocalTypedefWarnings();
+
// Modules don't need any of the checking below.
TUScope = nullptr;
return;
@@ -827,6 +844,8 @@
if (ExternalSource)
ExternalSource->ReadUndefinedButUsed(UndefinedButUsed);
checkUndefinedButUsed(*this);
+
+ emitAndClearUnusedLocalTypedefWarnings();
}
if (!Diags.isIgnored(diag::warn_unused_private_field, SourceLocation())) {
Index: lib/Sema/SemaCXXScopeSpec.cpp
===================================================================
--- lib/Sema/SemaCXXScopeSpec.cpp (revision 217285)
+++ lib/Sema/SemaCXXScopeSpec.cpp (working copy)
@@ -612,6 +612,9 @@
}
}
+ if (auto *TD = dyn_cast_or_null<TypedefNameDecl>(SD))
+ MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
+
// If we're just performing this lookup for error-recovery purposes,
// don't extend the nested-name-specifier. Just return now.
if (ErrorRecoveryLookup)
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp (revision 217285)
+++ lib/Sema/SemaDecl.cpp (working copy)
@@ -380,6 +380,7 @@
DiagnoseUseOfDecl(IIDecl, NameLoc);
T = Context.getTypeDeclType(TD);
+ MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
// NOTE: avoid constructing an ElaboratedType(Loc) if this is a
// constructor or destructor name (in such a case, the scope specifier
@@ -928,6 +929,7 @@
NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
if (TypeDecl *Type = dyn_cast<TypeDecl>(FirstDecl)) {
DiagnoseUseOfDecl(Type, NameLoc);
+ MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
QualType T = Context.getTypeDeclType(Type);
if (SS.isNotEmpty())
return buildNestedType(*this, SS, T, NameLoc);
@@ -1395,10 +1397,22 @@
if (isa<LabelDecl>(D))
return true;
+
+ // Except for labels, we only care about unused decls that are local to
+ // functions.
+ bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
+ if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
+ // For dependent types, the diagnostic is deferred.
+ WithinFunction =
+ WithinFunction || (R->isLocalClass() && !R->isDependentType());
+ if (!WithinFunction)
+ return false;
+
+ if (isa<TypedefNameDecl>(D))
+ return true;
// White-list anything that isn't a local variable.
- if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D) ||
- !D->getDeclContext()->isFunctionOrMethod())
+ if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D))
return false;
// Types of valid local variables should be complete, so this should succeed.
@@ -1461,11 +1475,30 @@
return;
}
+void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
+ if (D->getTypeForDecl()->isDependentType())
+ return;
+
+ for (auto *TmpD : D->decls()) {
+ if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
+ DiagnoseUnusedDecl(T);
+ else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
+ DiagnoseUnusedNestedTypedefs(R);
+ }
+}
+
/// DiagnoseUnusedDecl - Emit warnings about declarations that are not used
/// unless they are marked attr(unused).
void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
if (!ShouldDiagnoseUnusedDecl(D))
return;
+
+ if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
+ // typedefs can be referenced later on, so the diagnostics are emitted
+ // at end-of-translation-unit.
+ UnusedLocalTypedefNameCandidates.insert(TD);
+ return;
+ }
FixItHint Hint;
GenerateFixForUnusedDecl(D, Context, Hint);
@@ -1505,8 +1538,11 @@
if (!D->getDeclName()) continue;
// Diagnose unused variables in this scope.
- if (!S->hasUnrecoverableErrorOccurred())
+ if (!S->hasUnrecoverableErrorOccurred()) {
DiagnoseUnusedDecl(D);
+ if (const auto *RD = dyn_cast<RecordDecl>(D))
+ DiagnoseUnusedNestedTypedefs(RD);
+ }
// If this was a forward reference to a label, verify it was defined.
if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
Index: lib/Sema/SemaStmt.cpp
===================================================================
--- lib/Sema/SemaStmt.cpp (revision 217285)
+++ lib/Sema/SemaStmt.cpp (working copy)
@@ -19,6 +19,7 @@
#include "clang/AST/EvaluatedExprVisitor.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
+#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/StmtObjC.h"
#include "clang/AST/TypeLoc.h"
@@ -2710,6 +2711,40 @@
return Result;
}
+namespace {
+/// \brief Marks all typedefs in all local classes in a type referenced.
+///
+/// In a function like
+/// auto f() {
+/// struct S { typedef int a; };
+/// return S();
+/// }
+///
+/// the local type escapes and could be referenced in some TUs but not in
+/// others. Pretend that all local typedefs are always referenced, to not warn
+/// on this. This isn't necessary if f has internal linkage, or the typedef
+/// is private.
+class LocalTypedefNameReferencer
+ : public RecursiveASTVisitor<LocalTypedefNameReferencer> {
+public:
+ LocalTypedefNameReferencer(Sema &S) : S(S) {}
+ bool VisitRecordType(const RecordType *RT);
+private:
+ Sema &S;
+};
+bool LocalTypedefNameReferencer::VisitRecordType(const RecordType *RT) {
+ auto *R = dyn_cast<CXXRecordDecl>(RT->getDecl());
+ if (!R || !R->isLocalClass() || !R->isLocalClass()->isExternallyVisible() ||
+ R->isDependentType())
+ return true;
+ for (auto *TmpD : R->decls())
+ if (auto *T = dyn_cast<TypedefNameDecl>(TmpD))
+ if (T->getAccess() != AS_private || R->hasFriends())
+ S.MarkAnyDeclReferenced(T->getLocation(), T, /*OdrUse=*/false);
+ return true;
+}
+}
+
/// Deduce the return type for a function from a returned expression, per
/// C++1y [dcl.spec.auto]p6.
bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
@@ -2755,6 +2790,11 @@
if (DAR != DAR_Succeeded)
return true;
+
+ // If a local type is part of the returned type, mark its fields as
+ // referenced.
+ LocalTypedefNameReferencer Referencer(*this);
+ Referencer.TraverseType(RetExpr->getType());
} else {
// In the case of a return with no operand, the initializer is considered
// to be void().
Index: lib/Sema/SemaStmtAsm.cpp
===================================================================
--- lib/Sema/SemaStmtAsm.cpp (revision 217285)
+++ lib/Sema/SemaStmtAsm.cpp (working copy)
@@ -467,9 +467,10 @@
NamedDecl *FoundDecl = BaseResult.getFoundDecl();
if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl))
RT = VD->getType()->getAs<RecordType>();
- else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl))
+ else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl)) {
+ MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
RT = TD->getUnderlyingType()->getAs<RecordType>();
- else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
+ } else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
RT = TD->getTypeForDecl()->getAs<RecordType>();
if (!RT)
return true;
Index: lib/Sema/SemaTemplate.cpp
===================================================================
--- lib/Sema/SemaTemplate.cpp (revision 217285)
+++ lib/Sema/SemaTemplate.cpp (working copy)
@@ -7945,6 +7945,7 @@
if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
// We found a type. Build an ElaboratedType, since the
// typename-specifier was just sugar.
+ MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
return Context.getElaboratedType(ETK_Typename,
QualifierLoc.getNestedNameSpecifier(),
Context.getTypeDeclType(Type));
Index: lib/Sema/SemaTemplateInstantiateDecl.cpp
===================================================================
--- lib/Sema/SemaTemplateInstantiateDecl.cpp (revision 217285)
+++ lib/Sema/SemaTemplateInstantiateDecl.cpp (working copy)
@@ -1200,6 +1200,9 @@
SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
TSK_ImplicitInstantiation);
}
+
+ SemaRef.DiagnoseUnusedNestedTypedefs(Record);
+
return Record;
}
@@ -3653,7 +3656,7 @@
// Diagnose unused local variables with dependent types, where the diagnostic
// will have been deferred.
if (!NewVar->isInvalidDecl() &&
- NewVar->getDeclContext()->isFunctionOrMethod() && !NewVar->isUsed() &&
+ NewVar->getDeclContext()->isFunctionOrMethod() &&
OldVar->getType()->isDependentType())
DiagnoseUnusedDecl(NewVar);
}
Index: lib/Serialization/ASTReader.cpp
===================================================================
--- lib/Serialization/ASTReader.cpp (revision 217285)
+++ lib/Serialization/ASTReader.cpp (working copy)
@@ -3285,6 +3285,12 @@
}
OptimizeOffPragmaLocation = ReadSourceLocation(F, Record[0]);
break;
+
+ case UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES:
+ for (unsigned I = 0, N = Record.size(); I != N; ++I)
+ UnusedLocalTypedefNameCandidates.push_back(
+ getGlobalDeclID(F, Record[I]));
+ break;
}
}
}
@@ -7196,6 +7202,18 @@
DynamicClasses.clear();
}
+void ASTReader::ReadUnusedLocalTypedefNameCandidates(
+ llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) {
+ for (unsigned I = 0, N = UnusedLocalTypedefNameCandidates.size(); I != N;
+ ++I) {
+ TypedefNameDecl *D = dyn_cast_or_null<TypedefNameDecl>(
+ GetDecl(UnusedLocalTypedefNameCandidates[I]));
+ if (D)
+ Decls.insert(D);
+ }
+ UnusedLocalTypedefNameCandidates.clear();
+}
+
void
ASTReader::ReadLocallyScopedExternCDecls(SmallVectorImpl<NamedDecl *> &Decls) {
for (unsigned I = 0, N = LocallyScopedExternCDecls.size(); I != N; ++I) {
Index: lib/Serialization/ASTWriter.cpp
===================================================================
--- lib/Serialization/ASTWriter.cpp (revision 217285)
+++ lib/Serialization/ASTWriter.cpp (working copy)
@@ -4284,6 +4284,11 @@
}
}
+ // Build a record containing all of the UnusedLocalTypedefNameCandidates.
+ RecordData UnusedLocalTypedefNameCandidates;
+ for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
+ AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
+
// Build a record containing all of dynamic classes declarations.
RecordData DynamicClasses;
AddLazyVectorDecls(*this, SemaRef.DynamicClasses, DynamicClasses);
@@ -4561,6 +4566,11 @@
if (!DynamicClasses.empty())
Stream.EmitRecord(DYNAMIC_CLASSES, DynamicClasses);
+ // Write the record containing potentially unused local typedefs.
+ if (!UnusedLocalTypedefNameCandidates.empty())
+ Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
+ UnusedLocalTypedefNameCandidates);
+
// Write the record containing pending implicit instantiations.
if (!PendingInstantiations.empty())
Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
Index: test/Misc/ast-dump-color.cpp
===================================================================
--- test/Misc/ast-dump-color.cpp (revision 217285)
+++ test/Misc/ast-dump-color.cpp (working copy)
@@ -89,7 +89,7 @@
//CHECK: {{^}}[[Blue]]| `-[[RESET]][[BLUE]]GuardedByAttr[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:29[[RESET]], [[Yellow]]col:43[[RESET]]>{{$}}
//CHECK: {{^}}[[Blue]]| `-[[RESET]][[MAGENTA]]DeclRefExpr[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:40[[RESET]]> [[Green]]'class Mutex':'class Mutex'[[RESET]][[Cyan]] lvalue[[RESET]][[Cyan]][[RESET]] [[GREEN]]Var[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]][[CYAN]] 'mu1'[[RESET]] [[Green]]'class Mutex':'class Mutex'[[RESET]]{{$}}
//CHECK: {{^}}[[Blue]]|-[[RESET]][[GREEN]]CXXRecordDecl[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]line:28:1[[RESET]], [[Yellow]]line:30:1[[RESET]]> [[Yellow]]line:28:8[[RESET]] struct[[CYAN]] Invalid[[RESET]] definition
-//CHECK: {{^}}[[Blue]]| |-[[RESET]][[GREEN]]CXXRecordDecl[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:1[[RESET]], [[Yellow]]col:8[[RESET]]> [[Yellow]]col:8[[RESET]] implicit struct[[CYAN]] Invalid[[RESET]]
+//CHECK: {{^}}[[Blue]]| |-[[RESET]][[GREEN]]CXXRecordDecl[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:1[[RESET]], [[Yellow]]col:8[[RESET]]> [[Yellow]]col:8[[RESET]] implicit referenced struct[[CYAN]] Invalid[[RESET]]
//CHECK: {{^}}[[Blue]]| |-[[RESET]][[GREEN]]CXXConstructorDecl[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]line:29:3[[RESET]], [[Yellow]]col:42[[RESET]]> [[Yellow]]col:29[[RESET]] invalid[[CYAN]] Invalid[[RESET]] [[Green]]'void (int)'[[RESET]]
//CHECK: {{^}}[[Blue]]| | |-[[RESET]][[GREEN]]ParmVarDecl[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:37[[RESET]], [[Yellow]]<invalid sloc>[[RESET]]> [[Yellow]]col:42[[RESET]] invalid [[Green]]'int'[[RESET]]
//CHECK: {{^}}[[Blue]]| | `-[[RESET]][[BLUE]]NoInlineAttr[[RESET]][[Yellow]] 0x{{[0-9a-fA-F]*}}[[RESET]] <[[Yellow]]col:18[[RESET]]>
Index: test/Modules/Inputs/module.map
===================================================================
--- test/Modules/Inputs/module.map (revision 217285)
+++ test/Modules/Inputs/module.map (working copy)
@@ -292,6 +292,10 @@
header "warning.h"
}
+module warn_unused_local_typedef {
+ header "warn-unused-local-typedef.h"
+}
+
module initializer_list {
header "initializer_list"
}
Index: test/Modules/Inputs/warn-unused-local-typedef.h
===================================================================
--- test/Modules/Inputs/warn-unused-local-typedef.h (revision 0)
+++ test/Modules/Inputs/warn-unused-local-typedef.h (working copy)
@@ -0,0 +1 @@
+inline void myfun() { typedef int a; }
Index: test/Modules/warn-unused-local-typedef.cpp
===================================================================
--- test/Modules/warn-unused-local-typedef.cpp (revision 0)
+++ test/Modules/warn-unused-local-typedef.cpp (working copy)
@@ -0,0 +1,9 @@
+// RUN: rm -rf %t
+// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s 2>&1 | FileCheck %s -check-prefix=CHECK_1
+// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s 2>&1 | FileCheck %s -check-prefix=CHECK_2 -allow-empty
+
+// For modules, the warning should only fire the first time, when the module is
+// built.
+// CHECK_1: warning: unused typedef
+// CHECK_2-NOT: warning: unused typedef
+ at import warn_unused_local_typedef;
Index: test/SemaCXX/implicit-exception-spec.cpp
===================================================================
--- test/SemaCXX/implicit-exception-spec.cpp (revision 217285)
+++ test/SemaCXX/implicit-exception-spec.cpp (working copy)
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -fcxx-exceptions -verify -std=c++11 -Wall %s
+// RUN: %clang_cc1 -fsyntax-only -fcxx-exceptions -verify -std=c++11 -Wall -Wno-unused-local-typedefs %s
template<bool b> struct ExceptionIf { static int f(); };
template<> struct ExceptionIf<false> { typedef int f; };
Index: test/SemaCXX/warn-unused-filescoped.cpp
===================================================================
--- test/SemaCXX/warn-unused-filescoped.cpp (revision 217285)
+++ test/SemaCXX/warn-unused-filescoped.cpp (working copy)
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -Wno-c++11-extensions -std=c++98 %s
-// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -std=c++11 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -Wno-unused-local-typedefs -Wno-c++11-extensions -std=c++98 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wunused -Wunused-member-function -Wno-unused-local-typedefs -std=c++11 %s
#ifdef HEADER
Index: test/SemaCXX/warn-unused-local-typedef-serialize.cpp
===================================================================
--- test/SemaCXX/warn-unused-local-typedef-serialize.cpp (revision 0)
+++ test/SemaCXX/warn-unused-local-typedef-serialize.cpp (working copy)
@@ -0,0 +1,11 @@
+// RUN: %clang -x c++-header -c -Wunused-local-typedef %s -o %t.gch -Werror
+// RUN: %clang -DBE_THE_SOURCE -c -Wunused-local-typedef -include %t %s 2>&1 | FileCheck %s
+// RUN: %clang -DBE_THE_SOURCE -c -Wunused-local-typedef -include %t %s 2>&1 | FileCheck %s
+
+#ifndef BE_THE_SOURCE
+inline void myfun() {
+// The warning should fire every time the pch file is used, not when it's built.
+// CHECK: warning: unused typedef
+ typedef int a;
+}
+#endif
Index: test/SemaCXX/warn-unused-local-typedef.cpp
===================================================================
--- test/SemaCXX/warn-unused-local-typedef.cpp (revision 0)
+++ test/SemaCXX/warn-unused-local-typedef.cpp (working copy)
@@ -0,0 +1,232 @@
+// RUN: %clang_cc1 -fsyntax-only -Wunused-local-typedef -verify -std=c++1y -fasm-blocks %s
+
+struct S {
+ typedef int Foo; // no diag
+};
+
+namespace N {
+ typedef int Foo; // no diag
+ typedef int Foo2; // no diag
+}
+
+template <class T> class Vec {};
+
+typedef int global_foo; // no diag
+
+void f() {
+ typedef int foo0; // expected-warning {{unused typedef 'foo0'}}
+ using foo0alias = int ; // expected-warning {{unused type alias 'foo0alias'}}
+
+ typedef int foo1 __attribute__((unused)); // no diag
+
+ typedef int foo2;
+ {
+ typedef int foo2; // expected-warning {{unused typedef 'foo2'}}
+ }
+ typedef foo2 foo3; // expected-warning {{unused typedef 'foo3'}}
+
+ typedef int foo2_2; // expected-warning {{unused typedef 'foo2_2'}}
+ {
+ typedef int foo2_2;
+ typedef foo2_2 foo3_2; // expected-warning {{unused typedef 'foo3_2'}}
+ }
+
+ typedef int foo4;
+ foo4 the_thing;
+
+ typedef int* foo5;
+ typedef foo5* foo6; // no diag
+ foo6 *myptr;
+
+ struct S2 {
+ typedef int Foo; // no diag
+ typedef int Foo2; // expected-warning {{unused typedef 'Foo2'}}
+
+ struct Deeper {
+ typedef int DeepFoo; // expected-warning {{unused typedef 'DeepFoo'}}
+ };
+ };
+
+ S2::Foo s2foo;
+
+ typedef struct {} foostruct; // expected-warning {{unused typedef 'foostruct'}}
+
+ typedef struct {} foostruct2; // no diag
+ foostruct2 fs2;
+
+ typedef int vecint; // no diag
+ Vec<vecint> v;
+
+ N::Foo nfoo;
+
+ typedef int ConstExprInt;
+ static constexpr int a = (ConstExprInt)4;
+}
+
+int printf(char const *, ...);
+
+void test() {
+ typedef signed long int superint; // no diag
+ printf("%f", (superint) 42);
+
+ typedef signed long int superint2; // no diag
+ printf("%f", static_cast<superint2>(42));
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-local-typedef"
+ typedef int trungl_bot_was_here; // no diag
+#pragma clang diagnostic pop
+
+ typedef int foo; // expected-warning {{unused typedef 'foo'}}
+}
+
+template <class T>
+void template_fun(T t) {
+ typedef int foo; // expected-warning {{unused typedef 'foo'}}
+ typedef int bar; // no-diag
+ bar asdf;
+
+ struct S2 {
+ typedef int Foo; // no diag
+
+ // XXX this doesn't warn :-/
+ typedef int Foo2; // expected-warning {{unused typedef 'Foo2'}}
+
+ typedef int Foo3; // no diag
+ };
+
+ typename S2::Foo s2foo;
+ typename T::Foo s3foo;
+
+ typedef typename S2::Foo3 TTSF; // expected-warning {{unused typedef 'TTSF'}}
+}
+void template_fun_user() {
+ struct Local {
+ typedef int Foo; // no-diag
+ typedef int Bar; // expected-warning {{unused typedef 'Bar'}}
+ } p;
+ template_fun(p);
+}
+
+void typedef_in_nested_name() {
+ typedef struct {
+ typedef int Foo;
+ } A;
+ A::Foo adsf;
+
+ using A2 = struct {
+ typedef int Foo;
+ };
+ A2::Foo adsf2;
+}
+
+void use_in_asm() {
+ typedef struct {
+ int a;
+ int b;
+ } A;
+ __asm mov eax, [eax].A.b
+
+ using Alias = struct {
+ int a;
+ int b;
+ };
+ __asm mov eax, [eax].Alias.b
+}
+
+auto sneaky() {
+ struct S {
+ // Local typedefs can be used after the scope they were in has closed:
+ typedef int t;
+
+ // Even if they aren't, this could be an inline function that could be used
+ // in another TU, so this shouldn't warn either:
+ typedef int s;
+
+ private:
+ typedef int p; // expected-warning{{unused typedef 'p'}}
+ };
+ return S();
+}
+auto x = sneaky();
+decltype(x)::t y;
+
+static auto static_sneaky() {
+ struct S {
+ typedef int t;
+ // This function has internal linkage, so we can warn:
+ typedef int s; // expected-warning {{unused typedef 's'}}
+ };
+ return S();
+}
+auto sx = static_sneaky();
+decltype(sx)::t sy;
+
+auto sneaky_with_friends() {
+ struct S {
+ private:
+ friend class G;
+ // Can't warn if we have friends:
+ typedef int p;
+ };
+ return S();
+}
+
+namespace {
+auto nstatic_sneaky() {
+ struct S {
+ typedef int t;
+ // This function has internal linkage, so we can warn:
+ typedef int s; // expected-warning {{unused typedef 's'}}
+ };
+ return S();
+}
+auto nsx = nstatic_sneaky();
+decltype(nsx)::t nsy;
+}
+
+// Like sneaky(), but returning pointer to local type
+template<typename T>
+struct remove_reference { typedef T type; };
+template<typename T> struct remove_reference<T&> { typedef T type; };
+auto pointer_sneaky() {
+ struct S {
+ typedef int t;
+ typedef int s;
+ };
+ return (S*)nullptr;
+}
+remove_reference<decltype(*pointer_sneaky())>::type::t py;
+
+// Like sneaky(), but returning templated struct referencing local type.
+template <class T> struct container { int a; T t; };
+auto template_sneaky() {
+ struct S {
+ typedef int t;
+ typedef int s;
+ };
+ return container<S>();
+}
+auto tx = template_sneaky();
+decltype(tx.t)::t ty;
+
+// Like sneaky(), but doing its sneakiness by returning a member function
+// pointer.
+auto sneaky_memfun() {
+ struct S {
+ typedef int type;
+ int n;
+ };
+ return &S::n;
+}
+
+template <class T> void sneaky_memfun_g(int T::*p) {
+ typename T::type X;
+}
+
+void sneaky_memfun_h() {
+ sneaky_memfun_g(sneaky_memfun());
+}
+
+// This should not disable any warnings:
+#pragma clang diagnostic ignored "-Wunused-local-typedef"
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