inclyc updated this revision to Diff 462680.
inclyc added a comment.
Address comments.
Clang will now consider __builtin_offsetof #defined from "offsetof" to improve
diagnostic message.
For example:
#define offsetof(t, d) __builtin_offsetof(t, d)
int main() {
return offsetof(struct S { int a; }, a);
}
local/offsetof.c:4:26: error: 'S' cannot be defined in 'offsetof'
return offsetof(struct S { int a; }, a);
^
1 error generated.
Emm, the "expected-error" of struct B within a macro seems have to be annotated
at the same line as"struct A".
int macro(void) {
return offsetof(struct A // expected-error{{'A' cannot be defined in
'offsetof'}}
// expected-error@-1{{'B' cannot be defined in
'offsetof'}} <---- Have to write this here, but I believe the line number
is correct
{
int a;
struct B // FIXME: verifier seems to think the error is emitted by the
macro
// In fact the location of the error is "B" on the line above
{
int c;
int d;
} x;
}, a);
}
clang/test/C/C2x/n2350.c:11:36: error: 'A' cannot be defined in
'__builtin_offsetof'
return __builtin_offsetof(struct A // expected-error{{'A' cannot be defined
in '__builtin_offsetof'}}
^
clang/test/C/C2x/n2350.c:14:12: error: 'B' cannot be defined in
'__builtin_offsetof'
struct B // expected-error{{'B' cannot be defined in
'__builtin_offsetof'}}
^
clang/test/C/C2x/n2350.c:26:26: error: 'A' cannot be defined in 'offsetof'
return offsetof(struct A // expected-error{{'A' cannot be defined in
'offsetof'}}
^
clang/test/C/C2x/n2350.c:30:12: error: 'B' cannot be defined in 'offsetof'
<-- note that this line number is "30" (not "26")
struct B // FIXME: verifier seems to think the error is emitted by the
macro
^
4 errors generated.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D133574/new/
https://reviews.llvm.org/D133574
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/include/clang/Parse/Parser.h
clang/include/clang/Parse/RAIIObjectsForParser.h
clang/include/clang/Sema/Sema.h
clang/lib/Parse/ParseDecl.cpp
clang/lib/Parse/ParseDeclCXX.cpp
clang/lib/Parse/ParseExpr.cpp
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaDeclCXX.cpp
clang/lib/Sema/SemaTemplate.cpp
clang/test/C/C2x/n2350.c
clang/test/Parser/declarators.c
clang/test/SemaCXX/offsetof.cpp
Index: clang/test/SemaCXX/offsetof.cpp
===================================================================
--- clang/test/SemaCXX/offsetof.cpp
+++ clang/test/SemaCXX/offsetof.cpp
@@ -83,3 +83,20 @@
expected-error {{invalid application of 'offsetof' to a field of a virtual base}}
};
}
+
+// Reject definitions in __builtin_offsetof
+// https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm
+int test_definition(void) {
+ return __builtin_offsetof(struct A // expected-error{{'A' cannot be defined in '__builtin_offsetof'}}
+ {
+ int a;
+ struct B // FIXME: error diagnostic message for nested definitions
+ // https://reviews.llvm.org/D133574
+ // fixme-error{{'A' cannot be defined in '__builtin_offsetof'}}
+ {
+ int c;
+ int d;
+ };
+ B x;
+ }, a);
+}
Index: clang/test/Parser/declarators.c
===================================================================
--- clang/test/Parser/declarators.c
+++ clang/test/Parser/declarators.c
@@ -80,10 +80,6 @@
struct test10 { int a; } static test10x;
struct test11 { int a; } const test11x;
-// PR6216
-void test12(void) {
- (void)__builtin_offsetof(struct { char c; int i; }, i);
-}
// rdar://7608537
struct test13 { int a; } (test13x);
Index: clang/test/C/C2x/n2350.c
===================================================================
--- /dev/null
+++ clang/test/C/C2x/n2350.c
@@ -0,0 +1,50 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c89 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c99 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c11 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c17 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c2x -verify %s
+
+// Reject definitions in __builtin_offsetof
+// https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm
+int simple(void) {
+ return __builtin_offsetof(struct A // expected-error{{'A' cannot be defined in '__builtin_offsetof'}}
+ {
+ int a;
+ struct B // expected-error{{'B' cannot be defined in '__builtin_offsetof'}}
+ {
+ int c;
+ int d;
+ } x;
+ }, a);
+}
+
+#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
+
+
+int macro(void) {
+ return offsetof(struct A // expected-error{{'A' cannot be defined in 'offsetof'}}
+ // expected-error@-1{{'B' cannot be defined in 'offsetof'}}
+ {
+ int a;
+ struct B // FIXME: verifier seems to think the error is emitted by the macro
+ // In fact the location of the error is "B" on the line above
+ {
+ int c;
+ int d;
+ } x;
+ }, a);
+}
+
+#undef offsetof
+
+#define offsetof(TYPE, MEMBER) (&((TYPE *)0)->MEMBER)
+
+// no warning for traditional offsetof as a function-like macro
+int * macro_func(void) {
+ return offsetof(struct A // no-warning
+ {
+ int a;
+ int b;
+ }, a);
+}
Index: clang/lib/Sema/SemaTemplate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplate.cpp
+++ clang/lib/Sema/SemaTemplate.cpp
@@ -9978,13 +9978,13 @@
bool Owned = false;
bool IsDependent = false;
- Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
- KWLoc, SS, Name, NameLoc, Attr, AS_none,
- /*ModulePrivateLoc=*/SourceLocation(),
- MultiTemplateParamsArg(), Owned, IsDependent,
- SourceLocation(), false, TypeResult(),
- /*IsTypeSpecifier*/false,
- /*IsTemplateParamOrArg*/false);
+ Decl *TagD = ActOnTag(
+ S, TagSpec, Sema::TUK_Reference, KWLoc, SS, Name, NameLoc, Attr, AS_none,
+ /*ModulePrivateLoc=*/SourceLocation(), MultiTemplateParamsArg(), Owned,
+ IsDependent, SourceLocation(), false, TypeResult(),
+ /*IsTypeSpecifier*/ false,
+ /*IsTemplateParamOrArg*/ false, /*IsWithinOffsetOf=*/false,
+ /*IsOffsetOfInMacro=*/false);
assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
if (!TagD)
Index: clang/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- clang/lib/Sema/SemaDeclCXX.cpp
+++ clang/lib/Sema/SemaDeclCXX.cpp
@@ -16917,15 +16917,16 @@
if (SS.isEmpty()) {
bool Owned = false;
bool IsDependent = false;
- return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
- Attr, AS_public,
- /*ModulePrivateLoc=*/SourceLocation(),
- MultiTemplateParamsArg(), Owned, IsDependent,
- /*ScopedEnumKWLoc=*/SourceLocation(),
- /*ScopedEnumUsesClassTag=*/false,
- /*UnderlyingType=*/TypeResult(),
- /*IsTypeSpecifier=*/false,
- /*IsTemplateParamOrArg=*/false);
+ return ActOnTag(
+ S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, Attr, AS_public,
+ /*ModulePrivateLoc=*/SourceLocation(), MultiTemplateParamsArg(),
+ Owned, IsDependent,
+ /*ScopedEnumKWLoc=*/SourceLocation(),
+ /*ScopedEnumUsesClassTag=*/false,
+ /*UnderlyingType=*/TypeResult(),
+ /*IsTypeSpecifier=*/false,
+ /*IsTemplateParamOrArg=*/false, /*IsWithinOffsetOf=*/false,
+ /*IsOffsetOfInMacro=*/false);
}
NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -16256,6 +16256,7 @@
SourceLocation ScopedEnumKWLoc,
bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
bool IsTypeSpecifier, bool IsTemplateParamOrArg,
+ bool IsWithinOffsetOf, bool IsOffsetOfInMacro,
SkipBodyInfo *SkipBody) {
// If this is not a definition, it must have a name.
IdentifierInfo *OrigName = Name;
@@ -17029,10 +17030,16 @@
cast_or_null<RecordDecl>(PrevDecl));
}
+ if (IsWithinOffsetOf && TUK == TUK_Definition) {
+ Diag(New->getLocation(), diag::err_type_defined_in_offsetof)
+ << New << IsOffsetOfInMacro;
+ Invalid = true;
+ }
+
// C++11 [dcl.type]p3:
// A type-specifier-seq shall not define a class or enumeration [...].
- if (getLangOpts().CPlusPlus && (IsTypeSpecifier || IsTemplateParamOrArg) &&
- TUK == TUK_Definition) {
+ if (!Invalid && getLangOpts().CPlusPlus &&
+ (IsTypeSpecifier || IsTemplateParamOrArg) && TUK == TUK_Definition) {
Diag(New->getLocation(), diag::err_type_defined_in_type_specifier)
<< Context.getTagDeclType(New);
Invalid = true;
Index: clang/lib/Parse/ParseExpr.cpp
===================================================================
--- clang/lib/Parse/ParseExpr.cpp
+++ clang/lib/Parse/ParseExpr.cpp
@@ -2579,6 +2579,14 @@
}
case tok::kw___builtin_offsetof: {
SourceLocation TypeLoc = Tok.getLocation();
+ auto K = OffsetOfStateKind::Builtin;
+ if (Tok.getLocation().isMacroID()) {
+ StringRef MacroName = Lexer::getImmediateMacroNameForDiagnostics(
+ Tok.getLocation(), PP.getSourceManager(), getLangOpts());
+ if (MacroName == "offsetof")
+ K = OffsetOfStateKind::Macro;
+ }
+ OffsetOfStateRAIIObject InOffsetof(*this, K);
TypeResult Ty = ParseTypeName();
if (Ty.isInvalid()) {
SkipUntil(tok::r_paren, StopAtSemi);
Index: clang/lib/Parse/ParseDeclCXX.cpp
===================================================================
--- clang/lib/Parse/ParseDeclCXX.cpp
+++ clang/lib/Parse/ParseDeclCXX.cpp
@@ -2030,7 +2030,8 @@
DSC == DeclSpecContext::DSC_type_specifier,
DSC == DeclSpecContext::DSC_template_param ||
DSC == DeclSpecContext::DSC_template_type_arg,
- &SkipBody);
+ OffsetOfState != OffsetOfStateKind::Outside,
+ OffsetOfState == OffsetOfStateKind::Macro, &SkipBody);
// If ActOnTag said the type was dependent, try again with the
// less common call.
Index: clang/lib/Parse/ParseDecl.cpp
===================================================================
--- clang/lib/Parse/ParseDecl.cpp
+++ clang/lib/Parse/ParseDecl.cpp
@@ -4886,7 +4886,8 @@
DSC == DeclSpecContext::DSC_type_specifier,
DSC == DeclSpecContext::DSC_template_param ||
DSC == DeclSpecContext::DSC_template_type_arg,
- &SkipBody);
+ OffsetOfState != OffsetOfStateKind::Outside,
+ OffsetOfState == OffsetOfStateKind::Macro, &SkipBody);
if (SkipBody.ShouldSkip) {
assert(TUK == Sema::TUK_Definition && "can only skip a definition");
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -3276,6 +3276,7 @@
bool &IsDependent, SourceLocation ScopedEnumKWLoc,
bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
bool IsTypeSpecifier, bool IsTemplateParamOrArg,
+ bool IsWithinOffsetOf, bool IsOffsetOfInMacro,
SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
Index: clang/include/clang/Parse/RAIIObjectsForParser.h
===================================================================
--- clang/include/clang/Parse/RAIIObjectsForParser.h
+++ clang/include/clang/Parse/RAIIObjectsForParser.h
@@ -341,6 +341,19 @@
}
};
+ class OffsetOfStateRAIIObject {
+ Parser::OffsetOfStateKind &OffsetOfState;
+ Parser::OffsetOfStateKind OldValue;
+
+ public:
+ OffsetOfStateRAIIObject(Parser &P, Parser::OffsetOfStateKind Value)
+ : OffsetOfState(P.OffsetOfState), OldValue(P.OffsetOfState) {
+ OffsetOfState = Value;
+ }
+
+ ~OffsetOfStateRAIIObject() { OffsetOfState = OldValue; }
+ };
+
/// RAII object that makes sure paren/bracket/brace count is correct
/// after declaration/statement parsing, even when there's a parsing error.
class ParenBraceBracketBalancer {
Index: clang/include/clang/Parse/Parser.h
===================================================================
--- clang/include/clang/Parse/Parser.h
+++ clang/include/clang/Parse/Parser.h
@@ -61,6 +61,7 @@
friend class ColonProtectionRAIIObject;
friend class ParsingOpenMPDirectiveRAII;
friend class InMessageExpressionRAIIObject;
+ friend class OffsetOfStateRAIIObject;
friend class PoisonSEHIdentifiersRAIIObject;
friend class ObjCDeclContextSwitch;
friend class ParenBraceBracketBalancer;
@@ -247,6 +248,16 @@
/// function call.
bool CalledSignatureHelp = false;
+ enum OffsetOfStateKind {
+ // Not parsing a type within __builtin_offsetof
+ Outside,
+ // Parsing a type within __builtin_offsetof
+ Builtin,
+ // Parsing a type within macro "offsetof", defined in __buitin_offsetof
+ // To improve our diagnostic message
+ Macro,
+ } OffsetOfState = OffsetOfStateKind::Outside;
+
/// The "depth" of the template parameters currently being parsed.
unsigned TemplateParameterDepth;
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1646,6 +1646,8 @@
"%0 cannot be defined in a condition">;
def err_type_defined_in_enum : Error<
"%0 cannot be defined in an enumeration">;
+def err_type_defined_in_offsetof : Error<
+ "%0 cannot be defined in '%select{__builtin_offsetof|offsetof}1'">;
def note_pure_virtual_function : Note<
"unimplemented pure virtual method %0 in %1">;
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -284,6 +284,8 @@
``-Wunused-label`` warning.
- Implemented `WG14 N2508 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2508.pdf>`_,
so labels can placed everywhere inside a compound statement.
+- Reject type definitions in the ``type`` argument of ``__builtin_offsetof``
+ according to `WG14 N2350 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm>`_.
C++ Language Changes in Clang
-----------------------------
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