erik.pilkington created this revision.
erik.pilkington added reviewers: rjmccall, steven_wu.
Herald added subscribers: ributzka, dexonsmith, jkorous.
Instead, recommend using a real boolean type. Its possible to get away with
BOOL:1, if you only read from it in a context where its contextually converted
to bool, but its still broken if you, for instance, store it into a BOOL
variable or try to compare it with another BOOL. Given that, I don't think
there is any good reason to use it when there are better alternatives available.
rdar://29707989
https://reviews.llvm.org/D77070
Files:
clang/include/clang/Basic/DiagnosticGroups.td
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/include/clang/Sema/Sema.h
clang/lib/Sema/SemaDecl.cpp
clang/test/SemaObjC/signed-char-bool-bitfield-fixit.m
clang/test/SemaObjC/signed-char-bool-bitfield.m
Index: clang/test/SemaObjC/signed-char-bool-bitfield.m
===================================================================
--- /dev/null
+++ clang/test/SemaObjC/signed-char-bool-bitfield.m
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -verify %s -Wobjc-signed-char-bool
+// RUN: %clang_cc1 -xobjective-c++ -verify %s -Wobjc-signed-char-bool
+
+typedef signed char BOOL;
+
+struct S {
+ BOOL b : 1; // expected-warning {{BOOL bit-field of width 1 cannot represent YES when BOOL is a signed type}}
+ BOOL b2 : 2;
+};
+
+@interface X {
+ BOOL b : 1; // expected-warning {{BOOL bit-field of width 1 cannot represent YES when BOOL is a signed type}}
+ BOOL b2 : 2;
+}
+@end
Index: clang/test/SemaObjC/signed-char-bool-bitfield-fixit.m
===================================================================
--- /dev/null
+++ clang/test/SemaObjC/signed-char-bool-bitfield-fixit.m
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -Wobjc-signed-char-bool %s -fdiagnostics-parseable-fixits 2>&1 | FileCheck %s
+
+typedef signed char BOOL;
+
+struct S {
+ BOOL bf : 1;
+ // CHECK: fix-it:"{{.*}}.m":{6:3-6:7}:"bool"
+};
+
+@interface X {
+ BOOL bf : 1;
+ // CHECK: fix-it:"{{.*}}.m":{11:3-11:7}:"bool"
+}
+@end
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -16169,6 +16169,7 @@
// Note that FieldName may be null for anonymous bitfields.
ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
+ SourceRange TypeRange,
IdentifierInfo *FieldName,
QualType FieldTy, bool IsMsStruct,
Expr *BitWidth, bool *ZeroWidth) {
@@ -16259,6 +16260,16 @@
Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_width)
<< (unsigned)Value.getZExtValue() << (unsigned)TypeWidth;
}
+
+ if (getLangOpts().ObjC && NSAPIObj->isObjCBOOLType(FieldTy) &&
+ FieldTy->isSpecificBuiltinType(BuiltinType::SChar) &&
+ Value == 1) {
+ auto Builder = Diag(FieldLoc, diag::warn_objc_signed_char_bool_bitfield);
+ // The Foundation headers that define BOOL include <stdbool.h>, so its
+ // reasonable to assume that 'bool' is available.
+ if (TypeRange.isValid())
+ Builder << FixItHint::CreateReplacement(TypeRange, "bool");
+ }
}
return BitWidth;
@@ -16485,7 +16496,8 @@
BitWidth = nullptr;
// If this is declared as a bit-field, check the bit-field.
if (BitWidth) {
- BitWidth = VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth,
+ BitWidth = VerifyBitField(Loc, TInfo->getTypeLoc().getSourceRange(),
+ II, T, Record->isMsStruct(Context), BitWidth,
&ZeroWidth).get();
if (!BitWidth) {
InvalidDecl = true;
@@ -16676,7 +16688,8 @@
if (BitWidth) {
// 6.7.2.1p3, 6.7.2.1p4
- BitWidth = VerifyBitField(Loc, II, T, /*IsMsStruct*/false, BitWidth).get();
+ BitWidth = VerifyBitField(Loc, TInfo->getTypeLoc().getSourceRange(),
+ II, T, /*IsMsStruct*/false, BitWidth).get();
if (!BitWidth)
D.setInvalidType();
} else {
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -11401,9 +11401,10 @@
/// VerifyBitField - verifies that a bit field expression is an ICE and has
/// the correct width, and that the field type is valid.
- /// Returns false on success.
+ /// Returns BitWidth on success.
/// Can optionally return whether the bit-field is of width 0
- ExprResult VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName,
+ ExprResult VerifyBitField(SourceLocation FieldLoc, SourceRange TypeRange,
+ IdentifierInfo *FieldName,
QualType FieldTy, bool IsMsStruct,
Expr *BitWidth, bool *ZeroWidth = nullptr);
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5471,6 +5471,10 @@
InGroup<BitFieldEnumConversion>, DefaultIgnore;
def note_change_bitfield_sign : Note<
"consider making the bitfield type %select{unsigned|signed}0">;
+def warn_objc_signed_char_bool_bitfield : Warning<
+ "BOOL bit-field of width 1 cannot represent YES when BOOL "
+ "is a signed type">,
+ InGroup<ObjCSignedCharBoolBitfield>;
def warn_missing_braces : Warning<
"suggest braces around initialization of subobject">,
Index: clang/include/clang/Basic/DiagnosticGroups.td
===================================================================
--- clang/include/clang/Basic/DiagnosticGroups.td
+++ clang/include/clang/Basic/DiagnosticGroups.td
@@ -1082,11 +1082,13 @@
ObjCStringComparison
]>;
+def ObjCSignedCharBoolBitfield : DiagGroup<"objc-signed-char-bool-bitfield">;
def ObjCSignedCharBool : DiagGroup<"objc-signed-char-bool",
[ObjCSignedCharBoolImplicitIntConversion,
ObjCSignedCharBoolImplicitFloatConversion,
ObjCBoolConstantConversion,
- TautologicalObjCBoolCompare]>;
+ TautologicalObjCBoolCompare,
+ ObjCSignedCharBoolBitfield]>;
// Inline ASM warnings.
def ASMOperandWidths : DiagGroup<"asm-operand-widths">;
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