Index: clang/include/clang/AST/Decl.h
===================================================================
--- clang/include/clang/AST/Decl.h
+++ clang/include/clang/AST/Decl.h
@@ -356,6 +356,10 @@
/// a C++ class.
bool isCXXInstanceMember() const;
+ /// Determine if the declaration obeys the reserved identifier rules of the
+ /// given language
+ bool isReserved(const LangOptions &) const;
+
/// Determine what kind of linkage this entity has.
///
/// This is not the linkage as defined by the standard or the codegen notion
Index: clang/include/clang/Basic/DiagnosticGroups.td
===================================================================
--- clang/include/clang/Basic/DiagnosticGroups.td
+++ clang/include/clang/Basic/DiagnosticGroups.td
@@ -768,6 +768,9 @@
def DuplicateArgDecl : DiagGroup<"duplicate-method-arg">;
def SignedEnumBitfield : DiagGroup<"signed-enum-bitfield">;
+
+def ReservedIdentifier : DiagGroup<"reserved-identifier", [ReservedIdAsMacro]>;
+
// Unreachable code warning groups.
//
// The goal is make -Wunreachable-code on by default, in -Wall, or at
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -372,6 +372,10 @@
"%select{used|required to be captured for this use}1">,
InGroup<UnusedLambdaCapture>, DefaultIgnore;
+def warn_reserved_identifier: Warning<
+ "%0 is a reserved identifier">,
+ InGroup<ReservedIdentifier>, DefaultIgnore;
+
def warn_parameter_size: Warning<
"%0 is a large (%1 bytes) pass-by-value argument; "
"pass it by reference instead ?">, InGroup<LargeByValueCopy>;
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -2463,6 +2463,8 @@
SourceLocation Less,
SourceLocation Greater);
+ void warnOnReservedIdentifier(NamedDecl const *D);
+
Decl *ActOnDeclarator(Scope *S, Declarator &D);
NamedDecl *HandleDeclarator(Scope *S, Declarator &D,
Index: clang/lib/AST/Decl.cpp
===================================================================
--- clang/lib/AST/Decl.cpp
+++ clang/lib/AST/Decl.cpp
@@ -1078,6 +1078,41 @@
return L == getCachedLinkage();
}
+bool NamedDecl::isReserved(const LangOptions &LangOpts) const {
+ IdentifierInfo *II = getIdentifier();
+ if (!II)
+ return false;
+
+ StringRef Name = II->getName();
+ // '_' is not a valid identifier, but it's use is so common (e.g. to store
+ // ignored values) that we don't warn on it.
+ if (Name.size() <= 1)
+ return false;
+
+ // 17.4.3.1.2 Global names [lib.global.names]
+ if (Name[0] == '_') {
+
+ // Each name that begins with an underscore is reserved to the
+ // implementation for use as a name in the global namespace.
+ if (getDeclContext()->isTranslationUnit()) {
+ StorageClass SC = getStorageClass(this);
+ if (SC == SC_Extern || SC == SC_PrivateExtern || SC == SC_None)
+ return true;
+ }
+
+ // Each name that begins with an underscore followed by an uppercase letter
+ // (2.11) is reserved.
+ if (Name[1] == '_' || ('A' <= Name[1] && Name[1] <= 'Z'))
+ return true;
+ }
+
+ // Each name that contains a double underscore (__) is reserved.
+ if (LangOpts.CPlusPlus && Name.contains("__"))
+ return true;
+
+ return false;
+}
+
ObjCStringFormatFamily NamedDecl::getObjCFStringFormattingFamily() const {
StringRef name = getName();
if (name.empty()) return SFF_None;
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -5542,6 +5542,12 @@
return false;
}
+void Sema::warnOnReservedIdentifier(const NamedDecl *D) {
+ if (!Context.getSourceManager().isInSystemHeader(D->getLocation()) &&
+ D->isReserved(getLangOpts()))
+ Diag(D->getLocation(), diag::warn_reserved_identifier) << D;
+}
+
Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
D.setFunctionDefinitionKind(FunctionDefinitionKind::Declaration);
Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());
@@ -5887,6 +5893,7 @@
if (isInOpenMPDeclareTargetContext())
checkDeclIsAllowedInOpenMPTarget(nullptr, New);
+ warnOnReservedIdentifier(New);
return New;
}
@@ -13622,6 +13629,8 @@
if (getLangOpts().OpenCL)
deduceOpenCLAddressSpace(New);
+ warnOnReservedIdentifier(New);
+
return New;
}
@@ -16276,6 +16285,7 @@
} else if (SkipBody && SkipBody->ShouldSkip) {
return SkipBody->Previous;
} else {
+ warnOnReservedIdentifier(New);
return New;
}
}
@@ -17088,6 +17098,8 @@
i != end; ++i) {
FieldDecl *FD = cast<FieldDecl>(*i);
+ warnOnReservedIdentifier(FD);
+
// Get the type for the field.
const Type *FDTy = FD->getType().getTypePtr();
@@ -17813,6 +17825,8 @@
ActOnDocumentableDecl(New);
+ warnOnReservedIdentifier(New);
+
return New;
}
Index: clang/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- clang/lib/Sema/SemaDeclCXX.cpp
+++ clang/lib/Sema/SemaDeclCXX.cpp
@@ -10012,8 +10012,9 @@
DeclContext *LookupDC = dyn_cast<DeclContext>(D);
if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
- for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
+ for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i) {
ParameterLists.push_back(DD->getTemplateParameterList(i));
+ }
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
@@ -10985,6 +10986,9 @@
// for the namespace has the declarations that showed up in that particular
// namespace definition.
PushDeclContext(NamespcScope, Namespc);
+
+ warnOnReservedIdentifier(Namespc);
+
return Namespc;
}
@@ -12659,6 +12663,9 @@
PushOnScopeChains(NewND, S);
ActOnDocumentableDecl(NewND);
+
+ warnOnReservedIdentifier(NewND);
+
return NewND;
}
Index: clang/lib/Sema/SemaStmt.cpp
===================================================================
--- clang/lib/Sema/SemaStmt.cpp
+++ clang/lib/Sema/SemaStmt.cpp
@@ -541,6 +541,10 @@
return SubStmt;
}
+ if (!Context.getSourceManager().isInSystemHeader(IdentLoc) &&
+ TheDecl->isReserved(getLangOpts()))
+ Diag(IdentLoc, diag::warn_reserved_identifier) << TheDecl;
+
// Otherwise, things are good. Fill in the declaration and return it.
LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
TheDecl->setStmt(LS);
Index: clang/lib/Sema/SemaTemplate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplate.cpp
+++ clang/lib/Sema/SemaTemplate.cpp
@@ -1677,6 +1677,9 @@
if (ExportLoc.isValid())
Diag(ExportLoc, diag::warn_template_export_unsupported);
+ for (NamedDecl *P : Params)
+ warnOnReservedIdentifier(P);
+
return TemplateParameterList::Create(
Context, TemplateLoc, LAngleLoc,
llvm::makeArrayRef(Params.data(), Params.size()),
@@ -8668,6 +8671,7 @@
}
ActOnDocumentableDecl(NewDecl);
+ warnOnReservedIdentifier(NewDecl);
PushOnScopeChains(NewDecl, S);
return NewDecl;
}
Index: clang/test/Sema/reserved-identifier.c
===================================================================
--- /dev/null
+++ clang/test/Sema/reserved-identifier.c
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wreserved-identifier %s
+
+#define __oof foo__ // expected-warning {{macro name is a reserved identifier}}
+
+int foo__bar() { return 0; } // no-warning
+static int _bar() { return 0; } // no-warning
+static int _Bar() { return 0; } // expected-warning {{'_Bar' is a reserved identifier}}
+int _foo() { return 0; } // expected-warning {{'_foo' is a reserved identifier}}
+
+// This one is explicitly skipped by -Wreserved-identifier
+void *_; // no-warning
+
+void foo(unsigned int _Reserved) { // expected-warning {{'_Reserved' is a reserved identifier}}
+ unsigned int __1 = // expected-warning {{'__1' is a reserved identifier}}
+ _Reserved; // no-warning
+ goto __reserved;
+__reserved: // expected-warning {{'__reserved' is a reserved identifier}}
+ ;
+}
+
+enum __menu { // expected-warning {{'__menu' is a reserved identifier}}
+ __some, // expected-warning {{'__some' is a reserved identifier}}
+ _Other, // expected-warning {{'_Other' is a reserved identifier}}
+ _other // no-warning
+};
+
+struct __babar { // expected-warning {{'__babar' is a reserved identifier}}
+};
+
+typedef struct {
+ int _Field; // expected-warning {{'_Field' is a reserved identifier}}
+ int _field; // no-warning
+} _Typedef; // expected-warning {{'_Typedef' is a reserved identifier}}
+
+int foobar() {
+ return foo__bar(); // no-warning
+}
Index: clang/test/Sema/reserved-identifier.cpp
===================================================================
--- /dev/null
+++ clang/test/Sema/reserved-identifier.cpp
@@ -0,0 +1,54 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify -Wreserved-identifier %s
+
+int foo__bar() { return 0; } // expected-warning {{'foo__bar' is a reserved identifier}}
+static int _bar() { return 0; } // no-warning
+static int _Bar() { return 0; } // expected-warning {{'_Bar' is a reserved identifier}}
+int _barbouille() { return 0; } // expected-warning {{'_barbouille' is a reserved identifier}}
+
+void foo(unsigned int _Reserved) { // expected-warning {{'_Reserved' is a reserved identifier}}
+ unsigned int __1 = // expected-warning {{'__1' is a reserved identifier}}
+ _Reserved; // no-warning
+}
+
+// This one is explicitly skipped by -Wreserved-identifier
+void *_; // no-warning
+
+template <class T> constexpr bool __toucan = true; // expected-warning {{'__toucan' is a reserved identifier}}
+
+template <class T>
+concept _Barbotine = __toucan<T>; // expected-warning {{'_Barbotine' is a reserved identifier}}
+
+template <class __> // expected-warning {{'__' is a reserved identifier}}
+struct BarbeNoire {};
+
+template <class __> // expected-warning {{'__' is a reserved identifier}}
+void BarbeRousse() {}
+
+namespace _Barbidur { // expected-warning {{'_Barbidur' is a reserved identifier}}
+
+struct __barbidou {}; // expected-warning {{'__barbidou' is a reserved identifier}}
+struct _barbidou {}; // no-warning
+
+int __barbouille; // expected-warning {{'__barbouille' is a reserved identifier}}
+int _barbouille; // no-warning
+
+int __babar() { return 0; } // expected-warning {{'__babar' is a reserved identifier}}
+int _babar() { return 0; } // no-warning
+
+} // namespace _Barbidur
+
+class __barbapapa { // expected-warning {{'__barbapapa' is a reserved identifier}}
+ void _barbabelle() {} // no-warning
+ int _Barbalala; // expected-warning {{'_Barbalala' is a reserved identifier}}
+};
+
+enum class __menu { // expected-warning {{'__menu' is a reserved identifier}}
+ __some, // expected-warning {{'__some' is a reserved identifier}}
+ _Other // expected-warning {{'_Other' is a reserved identifier}}
+};
+
+using _Barbamama = __barbapapa; // expected-warning {{'_Barbamama' is a reserved identifier}}
+
+int foobar() {
+ return foo__bar(); // no-warning
+}