From: Saleem Abdulrasool Date: Sun, 22 Jun 2014 22:25:01 +0000 (+0000) Subject: MC: adjust text section flags for WoA X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=7a3698ecc95d16af547fce9acfd15ed81dd0ad55 MC: adjust text section flags for WoA Correct the section flags for code built for Windows on ARM with `-ffunction-sections`. Windows on ARM uses solely Thumb-2 instructions, and indicates that the function is thumb by placing it in a text section that has IMAGE_SCN_MEM_16BIT flag set. When we encounter a .section directive, a new section is constructed. This may be a text segment. In order to identify that we need the additional flag, expose the target triple through the ObjectFileInfo as this information is lost otherwise. Since any modern ARM targeting environment on Windows would be Thumb-2 (Windows ARM NT or Windows Embedded Compact), introducing a new flag to indicate the section attribute seems to be a bit overkill. Simply depend on the target triple. Since there is one location that this information is currently needed, creating a target specific assembly parser and delegating the parsing of section switches also feels a bit heavy handed. If it turns out that this information ends up changing additional behaviour, then it may be worth considering that alternative. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211481 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/MC/MCObjectFileInfo.h b/include/llvm/MC/MCObjectFileInfo.h index 1a56040e466..75294b5d732 100644 --- a/include/llvm/MC/MCObjectFileInfo.h +++ b/include/llvm/MC/MCObjectFileInfo.h @@ -14,13 +14,13 @@ #ifndef LLVM_MC_MCBJECTFILEINFO_H #define LLVM_MC_MCBJECTFILEINFO_H +#include "llvm/ADT/Triple.h" #include "llvm/Support/CodeGen.h" namespace llvm { class MCContext; class MCSection; class StringRef; - class Triple; class MCObjectFileInfo { protected: @@ -380,6 +380,7 @@ private: Reloc::Model RelocM; CodeModel::Model CMModel; MCContext *Ctx; + Triple TT; void InitMachOMCObjectFileInfo(Triple T); void InitELFMCObjectFileInfo(Triple T); @@ -388,6 +389,9 @@ private: /// InitEHFrameSection - Initialize EHFrameSection on demand. /// void InitEHFrameSection(); + +public: + const Triple &getTargetTriple() const { return TT; } }; } // end namespace llvm diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp index b76aaa47239..b9ba011a673 100644 --- a/lib/MC/MCObjectFileInfo.cpp +++ b/lib/MC/MCObjectFileInfo.cpp @@ -792,7 +792,7 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) { SectionKind::getDataRel()); } -void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm, +void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm, CodeModel::Model cm, MCContext &ctx) { RelocM = relocm; @@ -817,8 +817,9 @@ void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm, DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. DwarfAccelTypesSection = nullptr; // Used only by selected targets. - Triple T(TT); - Triple::ArchType Arch = T.getArch(); + TT = Triple(T); + + Triple::ArchType Arch = TT.getArch(); // FIXME: Checking for Arch here to filter out bogus triples such as // cellspu-apple-darwin. Perhaps we should fix in Triple? if ((Arch == Triple::x86 || Arch == Triple::x86_64 || @@ -826,17 +827,17 @@ void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm, Arch == Triple::arm64 || Arch == Triple::aarch64 || Arch == Triple::ppc || Arch == Triple::ppc64 || Arch == Triple::UnknownArch) && - (T.isOSDarwin() || T.isOSBinFormatMachO())) { + (TT.isOSDarwin() || TT.isOSBinFormatMachO())) { Env = IsMachO; - InitMachOMCObjectFileInfo(T); + InitMachOMCObjectFileInfo(TT); } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 || Arch == Triple::arm || Arch == Triple::thumb) && - (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) { + (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) { Env = IsCOFF; - InitCOFFMCObjectFileInfo(T); + InitCOFFMCObjectFileInfo(TT); } else { Env = IsELF; - InitELFMCObjectFileInfo(T); + InitELFMCObjectFileInfo(TT); } } diff --git a/lib/MC/MCParser/COFFAsmParser.cpp b/lib/MC/MCParser/COFFAsmParser.cpp index 8e8447f7b89..0d914efe874 100644 --- a/lib/MC/MCParser/COFFAsmParser.cpp +++ b/lib/MC/MCParser/COFFAsmParser.cpp @@ -13,6 +13,7 @@ #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCObjectFileInfo.h" #include "llvm/MC/MCParser/MCAsmLexer.h" #include "llvm/MC/MCRegisterInfo.h" #include "llvm/MC/MCSectionCOFF.h" @@ -378,6 +379,11 @@ bool COFFAsmParser::ParseDirectiveSection(StringRef, SMLoc) { return TokError("unexpected token in directive"); SectionKind Kind = computeSectionKind(Flags); + if (Kind.isText()) { + const Triple &T = getContext().getObjectFileInfo()->getTargetTriple(); + if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) + Flags |= COFF::IMAGE_SCN_MEM_16BIT; + } ParseSectionSwitch(SectionName, Flags, Kind, COMDATSymName, Type); return false; } diff --git a/test/MC/ARM/Windows/multiple-text-sections.s b/test/MC/ARM/Windows/multiple-text-sections.s new file mode 100644 index 00000000000..241eee4bcad --- /dev/null +++ b/test/MC/ARM/Windows/multiple-text-sections.s @@ -0,0 +1,58 @@ +@ RUN: llvm-mc -triple thumbv7-windows-itanium -filetype obj -o - %s \ +@ RUN: | llvm-readobj -s - | FileCheck %s + + .syntax unified + .text + .thumb + + .section .text,"xr",one_only,a + + .def a; + .scl 2; + .type 32; + .endef +a: + movs r0, #65 + bx lr + + .section .text,"xr",one_only,b + + .def b; + .scl 2; + .type 32; + .endef + .thumb_func +b: + movs r0, #66 + bx lr + +@ CHECK: Sections [ +@ CHECK: Section { +@ CHECK: Name: .text +@ CHECK: Characteristics [ +@ CHECK: IMAGE_SCN_CNT_CODE +@ CHECK: IMAGE_SCN_MEM_16BIT +@ CHECK: IMAGE_SCN_MEM_EXECUTE +@ CHECK: IMAGE_SCN_MEM_READ +@ CHECK: ] +@ CHECK: } +@ CHECK: Section { +@ CHECK: Name: .text +@ CHECK: Characteristics [ +@ CHECK: IMAGE_SCN_CNT_CODE +@ CHECK: IMAGE_SCN_MEM_16BIT +@ CHECK: IMAGE_SCN_MEM_EXECUTE +@ CHECK: IMAGE_SCN_MEM_READ +@ CHECK: ] +@ CHECK: } +@ CHECK: Section { +@ CHECK: Name: .text +@ CHECK: Characteristics [ +@ CHECK: IMAGE_SCN_CNT_CODE +@ CHECK: IMAGE_SCN_MEM_16BIT +@ CHECK: IMAGE_SCN_MEM_EXECUTE +@ CHECK: IMAGE_SCN_MEM_READ +@ CHECK: ] +@ CHECK: } +@ CHECK: ] +