r247618 - C11 _Bool bitfield diagnostic
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 23 15:09:28 PDT 2015
On Mon, Sep 21, 2015 at 3:21 PM, Alexey Samsonov <vonosmas at gmail.com> wrote:
> Do you plan to fix diagnostic emission for cases like "bool b : 4" in the
> near future, or it makes sense to revert this change until we reach
> consensus on the rules, and implementation?
>
Fixed in r248435.
> On Fri, Sep 18, 2015 at 11:17 PM, Nico Weber via cfe-commits <
> cfe-commits at lists.llvm.org> wrote:
>
>> On Fri, Sep 18, 2015 at 10:19 PM, Richard Smith <richard at metafoo.co.uk>
>> wrote:
>>
>>> On Fri, Sep 18, 2015 at 8:49 PM, Nico Weber <thakis at chromium.org> wrote:
>>>
>>>> On Fri, Sep 18, 2015 at 5:06 PM, Richard Smith <richard at metafoo.co.uk>
>>>> wrote:
>>>>
>>>>> On Wed, Sep 16, 2015 at 5:33 PM, Richard Smith <richard at metafoo.co.uk>
>>>>> wrote:
>>>>>
>>>>>> On Wed, Sep 16, 2015 at 5:27 PM, Nico Weber via cfe-commits <
>>>>>> cfe-commits at lists.llvm.org> wrote:
>>>>>>
>>>>>>> On Tue, Sep 15, 2015 at 5:50 PM, Richard Smith <
>>>>>>> richard at metafoo.co.uk> wrote:
>>>>>>>
>>>>>>>> On Tue, Sep 15, 2015 at 12:38 PM, Nico Weber <thakis at 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'.
>>>>>>
>>>>>
>>>>> I'm coming around to the opinion that we shouldn't give this warning
>>>>> on bool at all -- the point of the warning is to point out that an
>>>>> 'unsigned : 40;' bitfield can't hold 2**40 - 1, and values of that size
>>>>> will be truncated. There is no corresponding problematic case for bool, so
>>>>> we have a much weaker justification for warning in this case -- we have no
>>>>> idea what the user was trying to achieve, but we do not have a signal that
>>>>> their code is wrong.
>>>>>
>>>>> Thoughts?
>>>>>
>>>>
>>>> Makes sense to me :-) What about `bool : 16`?
>>>>
>>>
>>> I don't think it makes sense to treat bool : 3 and bool : 16
>>> differently. The fact that an unadorned bool would occupy 8 bits doesn't
>>> seem relevant to whether we should warn. Either we warn that there are
>>> padding bits, or we don't.
>>>
>>
>> Yup, makes sense.
>>
>>
>>>
>>>
>>>> , 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 <
>>>>>>>>> richard at metafoo.co.uk> wrote:
>>>>>>>>>
>>>>>>>>>> On Mon, Sep 14, 2015 at 7:07 PM, Rachel Craik <rcraik at 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 at metafo]Nico Weber ---09/14/2015 09:53:25 PM---On Mon,
>>>>>>>>>>> Sep 14, 2015 at 5:28 PM, Richard Smith <richard at metafoo.co.uk>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> From: Nico Weber <thakis at chromium.org>
>>>>>>>>>>> To: Richard Smith <richard at metafoo.co.uk>
>>>>>>>>>>> Cc: Rachel Craik/Toronto/IBM at IBMCA, cfe-commits <
>>>>>>>>>>> cfe-commits at lists.llvm.org>
>>>>>>>>>>> Date: 09/14/2015 09:53 PM
>>>>>>>>>>> Subject: Re: r247618 - C11 _Bool bitfield diagnostic
>>>>>>>>>>> Sent by: thakis at google.com
>>>>>>>>>>> ------------------------------
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Mon, Sep 14, 2015 at 5:28 PM, Richard Smith <
>>>>>>>>>>> *richard at metafoo.co.uk* <richard at metafoo.co.uk>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> On Mon, Sep 14, 2015 at 5:18 PM, Nico Weber via cfe-commits <
>>>>>>>>>>> *cfe-commits at lists.llvm.org* <cfe-commits at 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 at lists.llvm.org*
>>>>>>>>>>> <cfe-commits at 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 at lists.llvm.org* <cfe-commits at 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 at lists.llvm.org* <cfe-commits at 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 at lists.llvm.org
>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>>
>
>
> --
> Alexey Samsonov
> vonosmas at gmail.com
>
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