On Wed, Sep 16, 2015 at 5:27 PM, Nico Weber via cfe-commits <
cfe-commits@lists.llvm.org> wrote:
> On Tue, Sep 15, 2015 at 5:50 PM, Richard Smith <rich...@metafoo.co.uk>
> wrote:
>
>> On Tue, Sep 15, 2015 at 12:38 PM, Nico Weber <tha...@chromium.org> wrote:
>>
>>> With this patch, we warn on `bool a : 4;`, yet we don't warn on `bool b`
>>> (which has 8 bits storage, 1 bit value). Warning on `bool b` is silly of
>>> course, but why is warning on `bool a : 4` useful? That's like 50% more
>>> storage efficient than `bool b` ;-)
>>>
>>> It's possible that this is a good warning for some reason, but I don't
>>> quite see why yet.
>>>
>>
>> Why would we warn on "unsigned n : 57;"? The bit-field is wider than
>> necessary, and we have no idea what the programmer was trying to do
>>
>
> Warning on this kind of makes sense to me, as the field is wider than the
> default width of int. (Not warning on that doesn't seem terrible to me
> either though.)
>
> I'm only confused about the bool case with bitfield sizes < 8 I think. We
> warn that the bitfield is wider than the value size, even though it's
> smaller than the default storage size, and we don't warn on regular bools.
>
> To get an idea how often this warning fires, I ran it on a large-ish open
> source codebase I had flying around. The only place it fired on is one
> header in protobuf (extension_set.h). I looked at the history of that file,
> and it had a struct that used to look like
>
> struct Extension {
> SomeEnum e;
> bool a;
> bool b;
> bool c;
> int d;
> // ...some more stuff...
> };
>
> Someone then added another field to this and for some reason decided to do
> it like so:
>
> struct Extension {
> SomeEnum e;
> bool a;
> bool b1 : 4;
> bool b2 : 4;
> bool c;
> int d;
> // ...some more stuff...
> };
>
> Neither the commit message nor the review discussion mention the bitfield
> at all as far as I can tell. Now, given that this isn't a small struct and
> it has a bunch of normal bools, I don't know why they added the new field
> as bitfield while this wasn't deemed necessary for the existing bools. My
> best guess is that that they didn't want to add 3 bytes of padding (due to
> the int field), which seems like a decent reason.
>
> Had the warning been in place when this code got written, I suppose they
> had used ": 1" instead. Does this make this code much better? It doesn't
> seem like it to me. So after doing a warning quality eval, I'd suggest to
> not emit the warning for bool bitfields if the bitfield size is < 8. (But
> since the warning fires only very rarely, I don't feel very strongly about
> this.)
>
I agree it doesn't make the code /much/ better. But if I were reading that,
I would certainly pause for a few moments wondering what the author was
thinking. I also don't feel especially strongly about this, but I don't see
a good rationale for warning on 'bool : 9' but not on 'bool : 5'.
, but it doesn't seem likely they got that effect. Would you be more
>> convinced if we amended the diagnostic to provide a fixit suggesting using
>> an anonymous bit-field to insert padding?
>>
>
> Isn't the Right Fix (tm) to make bool bitfields 1 wide and rely on the
> compiler to figure out padding?
>
It depends; maybe the intent is to be compatible with some on-disk format,
and the explicit padding is important:
struct X {
int n : 3;
bool b : 3;
int n : 2;
};
Changing the bool bit-field to 1 bit without inserting an anonymous
bit-field would change the struct layout.
> On Mon, Sep 14, 2015 at 11:06 PM, Richard Smith <rich...@metafoo.co.uk>
>>> wrote:
>>>
>>>> On Mon, Sep 14, 2015 at 7:07 PM, Rachel Craik <rcr...@ca.ibm.com>
>>>> wrote:
>>>>
>>>>> As of DR262, the C standard clarified that the width of a bit-field
>>>>> can not exceed that of the specified type, and this change was primarily
>>>>> to
>>>>> ensure that Clang correctly enforced this part of the standard. Looking at
>>>>> the C++11 standard again, it states that although the specified width of a
>>>>> bit-field may exceed the number of bits in the *object representation*
>>>>> (which
>>>>> includes padding bits) of the specified type, the extra bits will not take
>>>>> any part in the bit-field's *value representation*.
>>>>>
>>>>> Taking this into account, it seems that the correct way to validate
>>>>> the width of a bit-field (ignoring the special case of MS in C mode) would
>>>>> be to use getIntWidth in C mode, and getTypeSize in C++ mode.
>>>>>
>>>>> I would be happy create a patch to make this change tomorrow if people
>>>>> are in agreement.
>>>>>
>>>> David Majnemer has already landed a couple of changes to fix this up,
>>>> so hopefully that won't be necessary. Thanks for working on this!
>>>>
>>>>> Rachel
>>>>>
>>>>>
>>>>> [image: Inactive hide details for Nico Weber ---09/14/2015 09:53:25
>>>>> PM---On Mon, Sep 14, 2015 at 5:28 PM, Richard Smith <richard@metafo]Nico
>>>>> Weber ---09/14/2015 09:53:25 PM---On Mon, Sep 14, 2015 at 5:28 PM, Richard
>>>>> Smith <rich...@metafoo.co.uk> wrote:
>>>>>
>>>>> From: Nico Weber <tha...@chromium.org>
>>>>> To: Richard Smith <rich...@metafoo.co.uk>
>>>>> Cc: Rachel Craik/Toronto/IBM@IBMCA, cfe-commits <
>>>>> cfe-commits@lists.llvm.org>
>>>>> Date: 09/14/2015 09:53 PM
>>>>> Subject: Re: r247618 - C11 _Bool bitfield diagnostic
>>>>> Sent by: tha...@google.com
>>>>> ------------------------------
>>>>>
>>>>>
>>>>>
>>>>> On Mon, Sep 14, 2015 at 5:28 PM, Richard Smith <
>>>>> *rich...@metafoo.co.uk* <rich...@metafoo.co.uk>> wrote:
>>>>>
>>>>> On Mon, Sep 14, 2015 at 5:18 PM, Nico Weber via cfe-commits <
>>>>> *cfe-commits@lists.llvm.org* <cfe-commits@lists.llvm.org>> wrote:
>>>>> This also fires for bool in C++ files, even though the commit
>>>>> message saying C11 and _Bool. Given the test changes, I suppose
>>>>> that's
>>>>> intentional? This fires a lot on existing code, for example
>>>>> protobuf:
>>>>>
>>>>>
>>>>> ../../third_party/protobuf/src/google/protobuf/extension_set.h:465:10:
>>>>> error: width of bit-field 'is_cleared' (4 bits) exceeds the width
>>>>> of its
>>>>> type; value will be truncated to 1 bit [-Werror,-Wbitfield-width]
>>>>> bool is_cleared : 4;
>>>>> ^
>>>>>
>>>>> ../../third_party/protobuf/src/google/protobuf/extension_set.h:472:10:
>>>>> error: width of bit-field 'is_lazy' (4 bits) exceeds the width of
>>>>> its type;
>>>>> value will be truncated to 1 bit [-Werror,-Wbitfield-width]
>>>>> bool is_lazy : 4;
>>>>> ^
>>>>>
>>>>> Is this expected? Is this a behavior change, or did the
>>>>> truncation happen previously and it's now just getting warned on?
>>>>>
>>>>> The code previously assumed that MSVC used the C rules here; it
>>>>> appears that's not true in all cases.
>>>>>
>>>>>
>>>>> This was on a Mac bot…
>>>>>
>>>>>
>>>>>
>>>>> Can we just remove the " || IsMsStruct
>>>>> || Context.getTargetInfo().getCXXABI().isMicrosoft()"? Is there some
>>>>> reason
>>>>> we need to prohibit overwide bitfields for MS bitfield layout, rather
>>>>> than
>>>>> just warning on them? (Does record layout fail somehow?)
>>>>> On Mon, Sep 14, 2015 at 2:27 PM, Rachel Craik via cfe-commits <
>>>>> *cfe-commits@lists.llvm.org* <cfe-commits@lists.llvm.org>>
>>>>> wrote:
>>>>> Author: rcraik
>>>>> Date: Mon Sep 14 16:27:36 2015
>>>>> New Revision: 247618
>>>>>
>>>>> URL:
>>>>> *http://llvm.org/viewvc/llvm-project?rev=247618&view=rev*
>>>>> <http://llvm.org/viewvc/llvm-project?rev=247618&view=rev>
>>>>> Log:
>>>>> C11 _Bool bitfield diagnostic
>>>>>
>>>>> Summary: Implement DR262 (for C). This patch will mainly
>>>>> affect bitfields of type _Bool
>>>>>
>>>>> Reviewers: fraggamuffin, rsmith
>>>>>
>>>>> Subscribers: hubert.reinterpretcast, cfe-commits
>>>>>
>>>>> Differential Revision: *http://reviews.llvm.org/D10018*
>>>>> <http://reviews.llvm.org/D10018>
>>>>>
>>>>> Modified:
>>>>> cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>>>>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>>> cfe/trunk/lib/Sema/SemaDecl.cpp
>>>>> cfe/trunk/test/CodeGen/bitfield-2.c
>>>>> cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp
>>>>> cfe/trunk/test/Misc/warning-flags.c
>>>>> cfe/trunk/test/Sema/bitfield.c
>>>>> cfe/trunk/test/SemaCXX/bitfield-layout.cpp
>>>>> cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
>>>>> cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
>>>>> cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp
>>>>> cfe/trunk/test/SemaObjC/class-bitfield.m
>>>>>
>>>>> Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>>>>> (original)
>>>>> +++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Mon
>>>>> Sep 14 16:27:36 2015
>>>>> @@ -32,6 +32,7 @@ def AutoImport : DiagGroup<"auto-import"
>>>>> def GNUBinaryLiteral : DiagGroup<"gnu-binary-literal">;
>>>>> def GNUCompoundLiteralInitializer :
>>>>> DiagGroup<"gnu-compound-literal-initializer">;
>>>>> def BitFieldConstantConversion :
>>>>> DiagGroup<"bitfield-constant-conversion">;
>>>>> +def BitFieldWidth : DiagGroup<"bitfield-width">;
>>>>> def ConstantConversion :
>>>>> DiagGroup<"constant-conversion", [
>>>>> BitFieldConstantConversion ] >;
>>>>> def LiteralConversion : DiagGroup<"literal-conversion">;
>>>>>
>>>>> Modified:
>>>>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>>> (original)
>>>>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon
>>>>> Sep 14 16:27:36 2015
>>>>> @@ -4314,20 +4314,21 @@ def err_bitfield_has_negative_width
>>>>> : Er
>>>>> def err_anon_bitfield_has_negative_width : Error<
>>>>> "anonymous bit-field has negative width (%0)">;
>>>>> def err_bitfield_has_zero_width : Error<"named bit-field %0
>>>>> has zero width">;
>>>>> -def err_bitfield_width_exceeds_type_size : Error<
>>>>> - "size of bit-field %0 (%1 bits) exceeds size of its type
>>>>> (%2 bits)">;
>>>>> -def err_anon_bitfield_width_exceeds_type_size : Error<
>>>>> - "size of anonymous bit-field (%0 bits) exceeds size of
>>>>> its type (%1 bits)">;
>>>>> +def err_bitfield_width_exceeds_type_width : Error<
>>>>> + "width of bit-field %0 (%1 bits) exceeds width of its
>>>>> type (%2 bit%s2)">;
>>>>> +def err_anon_bitfield_width_exceeds_type_width : Error<
>>>>> + "width of anonymous bit-field (%0 bits) exceeds width of
>>>>> its type "
>>>>> + "(%1 bit%s1)">;
>>>>> def err_incorrect_number_of_vector_initializers : Error<
>>>>> "number of elements must be either one or match the size
>>>>> of the vector">;
>>>>>
>>>>> // Used by C++ which allows bit-fields that are wider than
>>>>> the type.
>>>>> -def warn_bitfield_width_exceeds_type_size: Warning<
>>>>> - "size of bit-field %0 (%1 bits) exceeds the size of its
>>>>> type; value will be "
>>>>> - "truncated to %2 bits">;
>>>>> -def warn_anon_bitfield_width_exceeds_type_size : Warning<
>>>>> - "size of anonymous bit-field (%0 bits) exceeds size of
>>>>> its type; value will "
>>>>> - "be truncated to %1 bits">;
>>>>> +def warn_bitfield_width_exceeds_type_width: Warning<
>>>>> + "width of bit-field %0 (%1 bits) exceeds the width of its
>>>>> type; value will "
>>>>> + "be truncated to %2 bit%s2">, InGroup<BitFieldWidth>;
>>>>> +def warn_anon_bitfield_width_exceeds_type_width : Warning<
>>>>> + "width of anonymous bit-field (%0 bits) exceeds width of
>>>>> its type; value "
>>>>> + "will be truncated to %1 bit%s1">, InGroup<BitFieldWidth>;
>>>>>
>>>>> def warn_missing_braces : Warning<
>>>>> "suggest braces around initialization of subobject">,
>>>>>
>>>>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>>>>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Sep 14 16:27:36 2015
>>>>> @@ -12625,26 +12625,26 @@ ExprResult
>>>>> Sema::VerifyBitField(SourceLo
>>>>> }
>>>>>
>>>>> if (!FieldTy->isDependentType()) {
>>>>> - uint64_t TypeSize = Context.getTypeSize(FieldTy);
>>>>> - if (Value.getZExtValue() > TypeSize) {
>>>>> + uint64_t TypeWidth = Context.getIntWidth(FieldTy);
>>>>> + if (Value.ugt(TypeWidth)) {
>>>>> if (!getLangOpts().CPlusPlus || IsMsStruct ||
>>>>>
>>>>> Context.getTargetInfo().getCXXABI().isMicrosoft()) {
>>>>> if (FieldName)
>>>>> - return Diag(FieldLoc,
>>>>> diag::err_bitfield_width_exceeds_type_size)
>>>>> + return Diag(FieldLoc,
>>>>> diag::err_bitfield_width_exceeds_type_width)
>>>>> << FieldName << (unsigned)Value.getZExtValue()
>>>>> - << (unsigned)TypeSize;
>>>>> + << (unsigned)TypeWidth;
>>>>>
>>>>> - return Diag(FieldLoc,
>>>>> diag::err_anon_bitfield_width_exceeds_type_size)
>>>>> - << (unsigned)Value.getZExtValue() <<
>>>>> (unsigned)TypeSize;
>>>>> + return Diag(FieldLoc,
>>>>> diag::err_anon_bitfield_width_exceeds_type_width)
>>>>> + << (unsigned)Value.getZExtValue() <<
>>>>> (unsigned)TypeWidth;
>>>>> }
>>>>>
>>>>> if (FieldName)
>>>>> - Diag(FieldLoc,
>>>>> diag::warn_bitfield_width_exceeds_type_size)
>>>>> + Diag(FieldLoc,
>>>>> diag::warn_bitfield_width_exceeds_type_width)
>>>>> << FieldName << (unsigned)Value.getZExtValue()
>>>>> - << (unsigned)TypeSize;
>>>>> + << (unsigned)TypeWidth;
>>>>> else
>>>>> - Diag(FieldLoc,
>>>>> diag::warn_anon_bitfield_width_exceeds_type_size)
>>>>> - << (unsigned)Value.getZExtValue() <<
>>>>> (unsigned)TypeSize;
>>>>> + Diag(FieldLoc,
>>>>> diag::warn_anon_bitfield_width_exceeds_type_width)
>>>>> + << (unsigned)Value.getZExtValue() <<
>>>>> (unsigned)TypeWidth;
>>>>> }
>>>>> }
>>>>>
>>>>>
>>>>> Modified: cfe/trunk/test/CodeGen/bitfield-2.c
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/bitfield-2.c?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/bitfield-2.c?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/CodeGen/bitfield-2.c (original)
>>>>> +++ cfe/trunk/test/CodeGen/bitfield-2.c Mon Sep 14 16:27:36
>>>>> 2015
>>>>> @@ -237,7 +237,7 @@ unsigned long long test_5() {
>>>>> /***/
>>>>>
>>>>> struct s6 {
>>>>> - _Bool f0 : 2;
>>>>> + unsigned f0 : 2;
>>>>> };
>>>>>
>>>>> struct s6 g6 = { 0xF };
>>>>>
>>>>> Modified: cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp
>>>>> (original)
>>>>> +++ cfe/trunk/test/CodeGenCXX/warn-padded-packed.cpp Mon Sep
>>>>> 14 16:27:36 2015
>>>>> @@ -69,7 +69,7 @@ struct S12 {
>>>>>
>>>>> struct S13 { // expected-warning {{padding size of 'S13'
>>>>> with 6 bits to alignment boundary}}
>>>>> char c;
>>>>> - bool b : 10; // expected-warning {{size of bit-field 'b'
>>>>> (10 bits) exceeds the size of its type}}
>>>>> + bool b : 10; // expected-warning {{width of bit-field 'b'
>>>>> (10 bits) exceeds the width of its type}}
>>>>> };
>>>>>
>>>>> // The warnings are emitted when the layout of the structs
>>>>> is computed, so we have to use them.
>>>>>
>>>>> Modified: cfe/trunk/test/Misc/warning-flags.c
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Misc/warning-flags.c?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Misc/warning-flags.c?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/Misc/warning-flags.c (original)
>>>>> +++ cfe/trunk/test/Misc/warning-flags.c Mon Sep 14 16:27:36
>>>>> 2015
>>>>> @@ -18,7 +18,7 @@ This test serves two purposes:
>>>>>
>>>>> The list of warnings below should NEVER grow. It should
>>>>> gradually shrink to 0.
>>>>>
>>>>> -CHECK: Warnings without flags (92):
>>>>> +CHECK: Warnings without flags (90):
>>>>> CHECK-NEXT: ext_excess_initializers
>>>>> CHECK-NEXT:
>>>>> ext_excess_initializers_in_char_array_initializer
>>>>> CHECK-NEXT: ext_expected_semi_decl_list
>>>>> @@ -44,10 +44,8 @@ CHECK-NEXT: pp_pragma_once_in_main_fil
>>>>> CHECK-NEXT: pp_pragma_sysheader_in_main_file
>>>>> CHECK-NEXT: w_asm_qualifier_ignored
>>>>> CHECK-NEXT: warn_accessor_property_type_mismatch
>>>>> -CHECK-NEXT: warn_anon_bitfield_width_exceeds_type_size
>>>>> CHECK-NEXT: warn_arcmt_nsalloc_realloc
>>>>> CHECK-NEXT: warn_asm_label_on_auto_decl
>>>>> -CHECK-NEXT: warn_bitfield_width_exceeds_type_size
>>>>> CHECK-NEXT: warn_c_kext
>>>>> CHECK-NEXT:
>>>>> warn_call_to_pure_virtual_member_function_from_ctor_dtor
>>>>> CHECK-NEXT: warn_call_wrong_number_of_arguments
>>>>>
>>>>> Modified: cfe/trunk/test/Sema/bitfield.c
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/bitfield.c?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/bitfield.c?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/Sema/bitfield.c (original)
>>>>> +++ cfe/trunk/test/Sema/bitfield.c Mon Sep 14 16:27:36 2015
>>>>> @@ -6,7 +6,7 @@ struct a {
>>>>> int a : -1; // expected-error{{bit-field 'a' has negative
>>>>> width}}
>>>>>
>>>>> // rdar://6081627
>>>>> - int b : 33; // expected-error{{size of bit-field 'b' (33
>>>>> bits) exceeds size of its type (32 bits)}}
>>>>> + int b : 33; // expected-error{{width of bit-field 'b' (33
>>>>> bits) exceeds width of its type (32 bits)}}
>>>>>
>>>>> int c : (1 + 0.25); // expected-error{{expression is not
>>>>> an integer constant expression}}
>>>>> int d : (int)(1 + 0.25);
>>>>> @@ -22,9 +22,12 @@ struct a {
>>>>> int g : (_Bool)1;
>>>>>
>>>>> // PR4017
>>>>> - char : 10; // expected-error {{size of anonymous
>>>>> bit-field (10 bits) exceeds size of its type (8 bits)}}
>>>>> + char : 10; // expected-error {{width of anonymous
>>>>> bit-field (10 bits) exceeds width of its type (8 bits)}}
>>>>> unsigned : -2; // expected-error {{anonymous bit-field
>>>>> has negative width (-2)}}
>>>>> float : 12; // expected-error {{anonymous bit-field
>>>>> has non-integral type 'float'}}
>>>>> +
>>>>> + _Bool : 2; // expected-error {{width of anonymous
>>>>> bit-field (2 bits) exceeds width of its type (1 bit)}}
>>>>> + _Bool h : 5; // expected-error {{width of bit-field 'h'
>>>>> (5 bits) exceeds width of its type (1 bit)}}
>>>>> };
>>>>>
>>>>> struct b {unsigned x : 2;} x;
>>>>>
>>>>> Modified: cfe/trunk/test/SemaCXX/bitfield-layout.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/bitfield-layout.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/bitfield-layout.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/SemaCXX/bitfield-layout.cpp (original)
>>>>> +++ cfe/trunk/test/SemaCXX/bitfield-layout.cpp Mon Sep 14
>>>>> 16:27:36 2015
>>>>> @@ -5,25 +5,25 @@
>>>>>
>>>>> // Simple tests.
>>>>> struct Test1 {
>>>>> - char c : 9; // expected-warning {{size of bit-field 'c'
>>>>> (9 bits) exceeds the size of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> + char c : 9; // expected-warning {{width of bit-field 'c'
>>>>> (9 bits) exceeds the width of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> };
>>>>> CHECK_SIZE(Test1, 2);
>>>>> CHECK_ALIGN(Test1, 1);
>>>>>
>>>>> struct Test2 {
>>>>> - char c : 16; // expected-warning {{size of bit-field 'c'
>>>>> (16 bits) exceeds the size of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> + char c : 16; // expected-warning {{width of bit-field 'c'
>>>>> (16 bits) exceeds the width of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> };
>>>>> CHECK_SIZE(Test2, 2);
>>>>> CHECK_ALIGN(Test2, 2);
>>>>>
>>>>> struct Test3 {
>>>>> - char c : 32; // expected-warning {{size of bit-field 'c'
>>>>> (32 bits) exceeds the size of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> + char c : 32; // expected-warning {{width of bit-field 'c'
>>>>> (32 bits) exceeds the width of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> };
>>>>> CHECK_SIZE(Test3, 4);
>>>>> CHECK_ALIGN(Test3, 4);
>>>>>
>>>>> struct Test4 {
>>>>> - char c : 64; // expected-warning {{size of bit-field 'c'
>>>>> (64 bits) exceeds the size of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> + char c : 64; // expected-warning {{width of bit-field 'c'
>>>>> (64 bits) exceeds the width of its type; value will be truncated
>>>>> to 8 bits}}
>>>>> };
>>>>> CHECK_SIZE(Test4, 8);
>>>>> CHECK_ALIGN(Test4, 8);
>>>>>
>>>>> Modified:
>>>>> cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
>>>>> (original)
>>>>> +++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Mon
>>>>> Sep 14 16:27:36 2015
>>>>> @@ -1801,9 +1801,9 @@ namespace Bitfields {
>>>>> bool b : 1;
>>>>> unsigned u : 5;
>>>>> int n : 5;
>>>>> - bool b2 : 3;
>>>>> - unsigned u2 : 74; // expected-warning {{exceeds the
>>>>> size of its type}}
>>>>> - int n2 : 81; // expected-warning {{exceeds the size of
>>>>> its type}}
>>>>> + bool b2 : 3; // expected-warning {{exceeds the width of
>>>>> its type}}
>>>>> + unsigned u2 : 74; // expected-warning {{exceeds the
>>>>> width of its type}}
>>>>> + int n2 : 81; // expected-warning {{exceeds the width of
>>>>> its type}}
>>>>> };
>>>>>
>>>>> constexpr A a = { false, 33, 31, false, 0xffffffff,
>>>>> 0x7fffffff }; // expected-warning 2{{truncation}}
>>>>>
>>>>> Modified:
>>>>> cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
>>>>> (original)
>>>>> +++ cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp Mon
>>>>> Sep 14 16:27:36 2015
>>>>> @@ -872,7 +872,7 @@ namespace Lifetime {
>>>>>
>>>>> namespace Bitfields {
>>>>> struct A {
>>>>> - bool b : 3;
>>>>> + bool b : 1;
>>>>> int n : 4;
>>>>> unsigned u : 5;
>>>>> };
>>>>>
>>>>> Modified: cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp (original)
>>>>> +++ cfe/trunk/test/SemaCXX/ms_wide_bitfield.cpp Mon Sep 14
>>>>> 16:27:36 2015
>>>>> @@ -1,9 +1,10 @@
>>>>> // RUN: %clang_cc1 -fno-rtti -emit-llvm-only -triple
>>>>> i686-pc-win32 -fdump-record-layouts -fsyntax-only -mms-bitfields
>>>>> -verify %s
>>>>> 2>&1
>>>>>
>>>>> struct A {
>>>>> - char a : 9; // expected-error{{size of bit-field 'a' (9
>>>>> bits) exceeds size of its type (8 bits)}}
>>>>> - int b : 33; // expected-error{{size of bit-field 'b' (33
>>>>> bits) exceeds size of its type (32 bits)}}
>>>>> - bool c : 9; // expected-error{{size of bit-field 'c' (9
>>>>> bits) exceeds size of its type (8 bits)}}
>>>>> + char a : 9; // expected-error{{width of bit-field 'a' (9
>>>>> bits) exceeds width of its type (8 bits)}}
>>>>> + int b : 33; // expected-error{{width of bit-field 'b' (33
>>>>> bits) exceeds width of its type (32 bits)}}
>>>>> + bool c : 9; // expected-error{{width of bit-field 'c' (9
>>>>> bits) exceeds width of its type (1 bit)}}
>>>>> + bool d : 3; // expected-error{{width of bit-field 'd' (3
>>>>> bits) exceeds width of its type (1 bit)}}
>>>>> };
>>>>>
>>>>> int a[sizeof(A) == 1 ? 1 : -1];
>>>>>
>>>>> Modified: cfe/trunk/test/SemaObjC/class-bitfield.m
>>>>> URL:
>>>>>
>>>>> *http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/class-bitfield.m?rev=247618&r1=247617&r2=247618&view=diff*
>>>>>
>>>>> <http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/class-bitfield.m?rev=247618&r1=247617&r2=247618&view=diff>
>>>>>
>>>>>
>>>>> ==============================================================================
>>>>> --- cfe/trunk/test/SemaObjC/class-bitfield.m (original)
>>>>> +++ cfe/trunk/test/SemaObjC/class-bitfield.m Mon Sep 14
>>>>> 16:27:36 2015
>>>>> @@ -5,7 +5,7 @@
>>>>> int a : -1; // expected-error{{bit-field 'a' has negative
>>>>> width}}
>>>>>
>>>>> // rdar://6081627
>>>>> - int b : 33; // expected-error{{size of bit-field 'b' (33
>>>>> bits) exceeds size of its type (32 bits)}}
>>>>> + int b : 33; // expected-error{{width of bit-field 'b' (33
>>>>> bits) exceeds width of its type (32 bits)}}
>>>>>
>>>>> int c : (1 + 0.25); // expected-error{{expression is not
>>>>> an integer constant expression}}
>>>>> int d : (int)(1 + 0.25);
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> cfe-commits mailing list
>>>>> *cfe-commits@lists.llvm.org* <cfe-commits@lists.llvm.org>
>>>>> *http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits*
>>>>> <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> cfe-commits mailing list
>>>>> *cfe-commits@lists.llvm.org* <cfe-commits@lists.llvm.org>
>>>>> *http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits*
>>>>> <http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
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