r247618 - C11 _Bool bitfield diagnostic
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 16 17:27:43 PDT 2015
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.)
, 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?
>
> 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>
>>>>
>>>>
>>>>
>>>
>>
>
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