From: Artyom Skrobov Date: Mon, 27 Jan 2014 11:37:40 +0000 Subject: [PATCH] Add support for -funsigned-bitfields --- include/clang/AST/Decl.h | 12 ++++-- include/clang/AST/DeclObjC.h | 6 ++- include/clang/Basic/LangOptions.def | 1 + include/clang/Driver/Options.td | 4 +- lib/AST/Decl.cpp | 8 ++-- lib/CodeGen/CGRecordLayoutBuilder.cpp | 5 +++ lib/Driver/Tools.cpp | 8 ++-- lib/Frontend/CompilerInvocation.cpp | 1 + lib/Sema/SemaDecl.cpp | 5 ++- test/CodeGenCXX/unsigned-bitfields.c | 68 +++++++++++++++++++++++++++++++++ 10 files changed, 101 insertions(+), 17 deletions(-) create mode 100644 test/CodeGenCXX/unsigned-bitfields.c diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h index 439552d..288e9ac 100644 --- a/include/clang/AST/Decl.h +++ b/include/clang/AST/Decl.h @@ -2122,7 +2122,8 @@ public: class FieldDecl : public DeclaratorDecl, public Mergeable { // FIXME: This can be packed into the bitfields in Decl. bool Mutable : 1; - mutable unsigned CachedFieldIndex : 31; + TypeSpecifierSign TypeSpecSign : 2; + mutable unsigned CachedFieldIndex : 29; /// \brief An InClassInitStyle value, and either a bit width expression (if /// the InClassInitStyle value is ICIS_NoInit), or a pointer to the in-class @@ -2139,9 +2140,9 @@ protected: FieldDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable, - InClassInitStyle InitStyle) + InClassInitStyle InitStyle, TypeSpecifierSign TypeSpecSign) : DeclaratorDecl(DK, DC, IdLoc, Id, T, TInfo, StartLoc), - Mutable(Mutable), CachedFieldIndex(0), + Mutable(Mutable), TypeSpecSign(TypeSpecSign), CachedFieldIndex(0), InitializerOrBitWidth(BW, InitStyle) { assert((!BW || InitStyle == ICIS_NoInit) && "got initializer for bitfield"); } @@ -2151,7 +2152,8 @@ public: SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable, - InClassInitStyle InitStyle); + InClassInitStyle InitStyle, + TypeSpecifierSign TypeSpecSign = TSS_unspecified); static FieldDecl *CreateDeserialized(ASTContext &C, unsigned ID); @@ -2237,6 +2239,8 @@ public: FieldDecl *getCanonicalDecl() { return getFirstDecl(); } const FieldDecl *getCanonicalDecl() const { return getFirstDecl(); } + TypeSpecifierSign getTypeSpecSign() const { return TypeSpecSign; } + // Implement isa/cast/dyncast/etc. static bool classof(const Decl *D) { return classofKind(D->getKind()); } static bool classofKind(Kind K) { return K >= firstField && K <= lastField; } diff --git a/include/clang/AST/DeclObjC.h b/include/clang/AST/DeclObjC.h index 3947e35..df06a59 100644 --- a/include/clang/AST/DeclObjC.h +++ b/include/clang/AST/DeclObjC.h @@ -1317,7 +1317,8 @@ private: QualType T, TypeSourceInfo *TInfo, AccessControl ac, Expr *BW, bool synthesized) : FieldDecl(ObjCIvar, DC, StartLoc, IdLoc, Id, T, TInfo, BW, - /*Mutable=*/false, /*HasInit=*/ICIS_NoInit), + /*Mutable=*/false, /*HasInit=*/ICIS_NoInit, + TSS_unspecified), NextIvar(0), DeclAccess(ac), Synthesized(synthesized) {} public: @@ -1373,7 +1374,8 @@ class ObjCAtDefsFieldDecl : public FieldDecl { QualType T, Expr *BW) : FieldDecl(ObjCAtDefsField, DC, StartLoc, IdLoc, Id, T, /*TInfo=*/0, // FIXME: Do ObjCAtDefs have declarators ? - BW, /*Mutable=*/false, /*HasInit=*/ICIS_NoInit) {} + BW, /*Mutable=*/false, /*HasInit=*/ICIS_NoInit, + TSS_unspecified) {} public: static ObjCAtDefsFieldDecl *Create(ASTContext &C, DeclContext *DC, diff --git a/include/clang/Basic/LangOptions.def b/include/clang/Basic/LangOptions.def index 34dfea2..69e62cb 100644 --- a/include/clang/Basic/LangOptions.def +++ b/include/clang/Basic/LangOptions.def @@ -86,6 +86,7 @@ LANGOPT(MSBitfields , 1, 0, "Microsoft-compatible structure layout") LANGOPT(Freestanding, 1, 0, "freestanding implementation") LANGOPT(NoBuiltin , 1, 0, "disable builtin functions") LANGOPT(NoMathBuiltin , 1, 0, "disable math builtin functions") +LANGOPT(UnsignedBitfields , 1, 0, "use unsigned bitfields by default") BENIGN_LANGOPT(ThreadsafeStatics , 1, 1, "thread-safe static initializers") LANGOPT(POSIXThreads , 1, 0, "POSIX thread support") diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td index 25a1d12..7beb645 100644 --- a/include/clang/Driver/Options.td +++ b/include/clang/Driver/Options.td @@ -766,7 +766,7 @@ def fshow_overloads_EQ : Joined<["-"], "fshow-overloads=">, Group, Flag def fshow_column : Flag<["-"], "fshow-column">, Group, Flags<[CC1Option]>; def fshow_source_location : Flag<["-"], "fshow-source-location">, Group; def fspell_checking : Flag<["-"], "fspell-checking">, Group; -def fsigned_bitfields : Flag<["-"], "fsigned-bitfields">, Group; +def fsigned_bitfields : Flag<["-"], "fsigned-bitfields">, Group, Flags<[CC1Option]>; def fsigned_char : Flag<["-"], "fsigned-char">, Group; def fno_signed_char : Flag<["-"], "fno-signed-char">, Flags<[CC1Option]>, Group, HelpText<"Char is unsigned">; @@ -839,7 +839,7 @@ def freroll_loops : Flag<["-"], "freroll-loops">, Group, HelpText<"Turn on loop reroller">, Flags<[CC1Option]>; def fno_reroll_loops : Flag<["-"], "fno-reroll-loops">, Group, HelpText<"Turn off loop reroller">; -def funsigned_bitfields : Flag<["-"], "funsigned-bitfields">, Group; +def funsigned_bitfields : Flag<["-"], "funsigned-bitfields">, Group, Flags<[CC1Option]>; def funsigned_char : Flag<["-"], "funsigned-char">, Group; def fno_unsigned_char : Flag<["-"], "fno-unsigned-char">, Group; def funwind_tables : Flag<["-"], "funwind-tables">, Group; diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp index aa92805..a520e01 100644 --- a/lib/AST/Decl.cpp +++ b/lib/AST/Decl.cpp @@ -3096,14 +3096,16 @@ FieldDecl *FieldDecl::Create(const ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable, - InClassInitStyle InitStyle) { + InClassInitStyle InitStyle, + TypeSpecifierSign TypeSpecSign) { return new (C, DC) FieldDecl(Decl::Field, DC, StartLoc, IdLoc, Id, T, TInfo, - BW, Mutable, InitStyle); + BW, Mutable, InitStyle, TypeSpecSign); } FieldDecl *FieldDecl::CreateDeserialized(ASTContext &C, unsigned ID) { return new (C, ID) FieldDecl(Field, 0, SourceLocation(), SourceLocation(), - 0, QualType(), 0, 0, false, ICIS_NoInit); + 0, QualType(), 0, 0, false, ICIS_NoInit, + TSS_unspecified); } bool FieldDecl::isAnonymousStructOrUnion() const { diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp index a1cc2ae..27503a7 100644 --- a/lib/CodeGen/CGRecordLayoutBuilder.cpp +++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp @@ -242,6 +242,11 @@ CGBitFieldInfo CGBitFieldInfo::MakeInfo(CodeGenTypes &Types, uint64_t TypeSizeInBits = Types.getContext().toBits(TypeSizeInBytes); bool IsSigned = FD->getType()->isSignedIntegerOrEnumerationType(); + if (FD->getTypeSpecSign() == TSS_unspecified && + Types.getContext().getLangOpts().UnsignedBitfields) { + // We default to signed bitfields unless -funsigned-bitfields is given. + IsSigned = false; + } if (Size > TypeSizeInBits) { // We have a wide bit-field. The extra bits are only used for padding, so diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp index 3e9ebf8..f8e5afe 100644 --- a/lib/Driver/Tools.cpp +++ b/lib/Driver/Tools.cpp @@ -3462,12 +3462,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, else if (!Args.hasFlag(options::OPT_fcommon, options::OPT_fno_common)) CmdArgs.push_back("-fno-common"); - // -fsigned-bitfields is default, and clang doesn't yet support - // -funsigned-bitfields. + // -fsigned-bitfields is default if (!Args.hasFlag(options::OPT_fsigned_bitfields, - options::OPT_funsigned_bitfields)) - D.Diag(diag::warn_drv_clang_unsupported) - << Args.getLastArg(options::OPT_funsigned_bitfields)->getAsString(Args); + options::OPT_funsigned_bitfields)) + CmdArgs.push_back("-funsigned-bitfields"); // -fsigned-bitfields is default, and clang doesn't support -fno-for-scope. if (!Args.hasFlag(options::OPT_ffor_scope, diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp index 92202b7..63b0797 100644 --- a/lib/Frontend/CompilerInvocation.cpp +++ b/lib/Frontend/CompilerInvocation.cpp @@ -1378,6 +1378,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK, Opts.DebuggerObjCLiteral = Args.hasArg(OPT_fdebugger_objc_literal); Opts.ApplePragmaPack = Args.hasArg(OPT_fapple_pragma_pack); Opts.CurrentModule = Args.getLastArgValue(OPT_fmodule_name); + Opts.UnsignedBitfields = Args.hasArg(OPT_funsigned_bitfields); if (Arg *A = Args.getLastArg(OPT_faddress_space_map_mangling_EQ)) { switch (llvm::StringSwitch(A->getValue()) diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 33cb77f..eb9ec90 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -11524,8 +11524,11 @@ FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, if (InitStyle != ICIS_NoInit) checkDuplicateDefaultInit(*this, cast(Record), Loc); + TypeSpecifierSign TSS = D ? D->getDeclSpec().getTypeSpecSign() + : TSS_unspecified; + FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo, - BitWidth, Mutable, InitStyle); + BitWidth, Mutable, InitStyle, TSS); if (InvalidDecl) NewFD->setInvalidDecl(); diff --git a/test/CodeGenCXX/unsigned-bitfields.c b/test/CodeGenCXX/unsigned-bitfields.c new file mode 100644 index 0000000..30965a6 --- /dev/null +++ b/test/CodeGenCXX/unsigned-bitfields.c @@ -0,0 +1,68 @@ +// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck -check-prefix SIGNED %s +// RUN: %clang_cc1 %s -emit-llvm -o - -fsigned-bitfields | FileCheck -check-prefix SIGNED %s +// RUN: %clang_cc1 %s -emit-llvm -o - -funsigned-bitfields | FileCheck -check-prefix UNSIGNED %s + +struct bitfield { + char padding : 4; + int m_unspec : 4; + signed m_signed : 4; + unsigned m_unsigned : 4; +} data; + +// SIGNED-LABEL: load1 +// UNSIGNED-LABEL: load1 +int load1() +{ + return data.m_unspec; +// SIGNED: ashr +// UNSIGNED: lshr +} + +// SIGNED-LABEL: load2 +// UNSIGNED-LABEL: load2 +int load2() +{ + return data.m_signed; +// SIGNED: ashr +// UNSIGNED: ashr +} + +// SIGNED-LABEL: load3 +// UNSIGNED-LABEL: load3 +int load3() +{ + return data.m_unsigned; +// SIGNED: lshr +// UNSIGNED: lshr +} + +// SIGNED-LABEL: store1 +// UNSIGNED-LABEL: store1 +int store1() +{ + return ++data.m_unspec; +// SIGNED: shl +// SIGNED: ashr +// UNSIGNED-NOT: ashr +} + +// SIGNED-LABEL: store2 +// UNSIGNED-LABEL: store2 +int store2() +{ + return ++data.m_signed; +// SIGNED: shl +// SIGNED: ashr +// UNSIGNED: shl +// UNSIGNED: ashr +} + +// SIGNED-LABEL: store3 +// UNSIGNED-LABEL: store3 +int store3() +{ + return ++data.m_unsigned; +// SIGNED-NOT: ashr +// UNSIGNED-NOT: ashr +} + -- 1.7.9.5