On Mon, Sep 14, 2015 at 5:28 PM, Richard Smith <rich...@metafoo.co.uk> wrote:
> On Mon, Sep 14, 2015 at 5:18 PM, Nico Weber via cfe-commits < > 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> 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 >>> 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 >>> >>> 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> >>> ============================================================================== >>> --- 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 >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >>> >> >> >> _______________________________________________ >> cfe-commits mailing list >> cfe-commits@lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >> >> >
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