[lld] r234009 - [ARM] Implementation of R_ARM_TARGET1 relocation

Evgeniy Stepanov eugeni.stepanov at gmail.com
Fri Apr 3 06:39:04 PDT 2015


Hi,

bots are complaining about this chunk (for some reason blaming me for it):

> +  bool target1Rel() const { return _ctx.armTarget1Rel(); }

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/17163/steps/bootstrap%20clang/logs/stdio

On Fri, Apr 3, 2015 at 3:03 PM, Leny Kholodov
<lkholodov at accesssoftek.com> wrote:
> Author: lkholodov
> Date: Fri Apr  3 07:03:47 2015
> New Revision: 234009
>
> URL: http://llvm.org/viewvc/llvm-project?rev=234009&view=rev
> Log:
> [ARM] Implementation of R_ARM_TARGET1 relocation
>
> This patch provides implementation of R_ARM_TARGET1 relocation with
> configuration of its behaviour from a command line. This patch provides
> two command line options for GnuLd driver: --arm-target1-rel and
> --arm-target1-abs (similar to ld option names with extra prefix 'arm-').
> So user may choose which behaviour of R_ARM_TARGET1 is preferred for his
> implementation of libc.
>
> Differential Revision: http://reviews.llvm.org/D8707
>
>
> Added:
>     lld/trunk/test/elf/ARM/rel-arm-target1.test
>     lld/trunk/test/elf/options/target-specific-args.test
> Modified:
>     lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
>     lld/trunk/lib/Driver/GnuLdDriver.cpp
>     lld/trunk/lib/Driver/GnuLdOptions.td
>     lld/trunk/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp
>     lld/trunk/lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h
>
> Modified: lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h?rev=234009&r1=234008&r2=234009&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h (original)
> +++ lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h Fri Apr  3 07:03:47 2015
> @@ -302,6 +302,10 @@ public:
>    script::Sema &linkerScriptSema() { return _linkerScriptSema; }
>    const script::Sema &linkerScriptSema() const { return _linkerScriptSema; }
>
> +  // Set R_ARM_TARGET1 relocation behaviour
> +  bool armTarget1Rel() const { return _armTarget1Rel; }
> +  void setArmTarget1Rel(bool value) { _armTarget1Rel = value; }
> +
>  protected:
>    ELFLinkingContext(llvm::Triple triple, std::unique_ptr<TargetHandler> handler)
>        : _triple(triple), _targetHandler(std::move(handler)) {}
> @@ -327,6 +331,7 @@ protected:
>    bool _stripSymbols = false;
>    bool _alignSegments = true;
>    bool _collectStats = false;
> +  bool _armTarget1Rel = false;
>    uint64_t _maxPageSize = 0x1000;
>
>    OutputMagic _outputMagic;
>
> Modified: lld/trunk/lib/Driver/GnuLdDriver.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Driver/GnuLdDriver.cpp?rev=234009&r1=234008&r2=234009&view=diff
> ==============================================================================
> --- lld/trunk/lib/Driver/GnuLdDriver.cpp (original)
> +++ lld/trunk/lib/Driver/GnuLdDriver.cpp Fri Apr  3 07:03:47 2015
> @@ -543,6 +543,25 @@ bool GnuLdDriver::parse(int argc, const
>    if (auto *arg = parsedArgs->getLastArg(OPT_output_filetype))
>      ctx->setOutputFileType(arg->getValue());
>
> +  // Process ELF/ARM specific options
> +  bool hasArmTarget1Rel = parsedArgs->hasArg(OPT_arm_target1_rel);
> +  bool hasArmTarget1Abs = parsedArgs->hasArg(OPT_arm_target1_abs);
> +  if (triple.getArch() == llvm::Triple::arm) {
> +    if (hasArmTarget1Rel && hasArmTarget1Abs) {
> +      diag << "error: options --arm-target1-rel and --arm-target1-abs"
> +              " can't be used together.\n";
> +      return false;
> +    } else if (hasArmTarget1Rel || hasArmTarget1Abs) {
> +      ctx->setArmTarget1Rel(hasArmTarget1Rel && !hasArmTarget1Abs);
> +    }
> +  } else if (hasArmTarget1Rel) {
> +    diag << "warning: ignoring unsupported ARM/ELF specific argument: "
> +         << "--arm-target1-rel\n";
> +  } else if (hasArmTarget1Abs) {
> +    diag << "warning: ignoring unsupported ARM/ELF specific argument: "
> +         << "--arm-target1-abs\n";
> +  }
> +
>    for (auto *arg : parsedArgs->filtered(OPT_L))
>      ctx->addSearchPath(arg->getValue());
>
>
> Modified: lld/trunk/lib/Driver/GnuLdOptions.td
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Driver/GnuLdOptions.td?rev=234009&r1=234008&r2=234009&view=diff
> ==============================================================================
> --- lld/trunk/lib/Driver/GnuLdOptions.td (original)
> +++ lld/trunk/lib/Driver/GnuLdOptions.td Fri Apr  3 07:03:47 2015
> @@ -313,6 +313,16 @@ def alias_output_filetype: Joined<["--"]
>        Alias<output_filetype>;
>
>  //===----------------------------------------------------------------------===//
> +/// Target Specific Options
> +//===----------------------------------------------------------------------===//
> +def grp_targetopts : OptionGroup<"opts">,
> +     HelpText<"ARCH SPECIFIC OPTIONS">;
> +def arm_target1_rel : Flag<["--"], "arm-target1-rel">,
> +     Group<grp_targetopts>, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_REL32">;
> +def arm_target1_abs : Flag<["--"], "arm-target1-abs">,
> +     Group<grp_targetopts>, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_ABS32">;
> +
> +//===----------------------------------------------------------------------===//
>  /// Ignored options
>  //===----------------------------------------------------------------------===//
>  def grp_ignored: OptionGroup<"ignored">,
>
> Modified: lld/trunk/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp?rev=234009&r1=234008&r2=234009&view=diff
> ==============================================================================
> --- lld/trunk/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp (original)
> +++ lld/trunk/lib/ReaderWriter/ELF/ARM/ARMRelocationHandler.cpp Fri Apr  3 07:03:47 2015
> @@ -84,6 +84,7 @@ static Reference::Addend readAddend(cons
>    switch (kindValue) {
>    case R_ARM_ABS32:
>    case R_ARM_REL32:
> +  case R_ARM_TARGET1:
>    case R_ARM_GOT_BREL:
>    case R_ARM_BASE_PREL:
>    case R_ARM_TLS_IE32:
> @@ -529,6 +530,14 @@ std::error_code ARMTargetRelocationHandl
>      relocR_ARM_REL32(location, relocVAddress, targetVAddress, addend,
>                       addressesThumb);
>      break;
> +  case R_ARM_TARGET1:
> +    if (_armLayout.target1Rel())
> +      relocR_ARM_REL32(location, relocVAddress, targetVAddress, addend,
> +                       addressesThumb);
> +    else
> +      relocR_ARM_ABS32(location, relocVAddress, targetVAddress, addend,
> +                       addressesThumb);
> +    break;
>    case R_ARM_THM_CALL:
>      // TODO: consider adding bool variable to disable J1 & J2 for archs
>      // before ARMv6
>
> Modified: lld/trunk/lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h?rev=234009&r1=234008&r2=234009&view=diff
> ==============================================================================
> --- lld/trunk/lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h (original)
> +++ lld/trunk/lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h Fri Apr  3 07:03:47 2015
> @@ -45,6 +45,8 @@ public:
>      llvm_unreachable("TLS segment not found");
>    }
>
> +  bool target1Rel() const { return _ctx.armTarget1Rel(); }
> +
>  private:
>    // TCB block size of the TLS.
>    enum { TCB_SIZE = 0x8 };
>
> Added: lld/trunk/test/elf/ARM/rel-arm-target1.test
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/ARM/rel-arm-target1.test?rev=234009&view=auto
> ==============================================================================
> --- lld/trunk/test/elf/ARM/rel-arm-target1.test (added)
> +++ lld/trunk/test/elf/ARM/rel-arm-target1.test Fri Apr  3 07:03:47 2015
> @@ -0,0 +1,116 @@
> +# Check handling of R_ARM_TARGET1 relocation.
> +#
> +# 1. R_ARM_TARGET1 is equal to R_ARM_ABS32
> +# RUN: yaml2obj -format=elf -docnum 1 %s > %t-abs32.o
> +# RUN: lld -flavor gnu -target arm -m armelf_linux_eabi -Bstatic \
> +# RUN: --noinhibit-exec --arm-target1-abs %t-abs32.o -o %t-abs32
> +# RUN: llvm-objdump -s -t %t-abs32 | FileCheck -check-prefix=CHECK-ABS32 %s
> +#
> +# CHECK-ABS32: Contents of section .data:
> +# CHECK-ABS32-NEXT: 401000 84004000
> +# CHECK-ABS32: SYMBOL TABLE:
> +# CHECK-ABS32: 00400074 g     F .text  {{[0-9a-f]+}} main
> +# CHECK-ABS32: 00401000 g       .data  00000004 data
> +#
> +# 2. R_ARM_TARGET1 is equal to R_ARM_REL32
> +# Check handling of R_ARM_REL32 relocation.
> +# RUN: yaml2obj -format=elf %s -docnum 2 > %t-rel32.o
> +# RUN: lld -flavor gnu -target arm -m armelf_linux_eabi -Bstatic \
> +# RUN: --noinhibit-exec --arm-target1-rel %t-rel32.o -o %t-rel32
> +# RUN: llvm-objdump -s -t %t-rel32 | FileCheck -check-prefix=CHECK-REL32 %s
> +#
> +# CHECK-REL32: Contents of section .text:
> +# CHECK-REL32-NEXT: 400074 {{[0-9a-f]+}} 880fff00
> +# CHECK-REL32: SYMBOL TABLE:
> +# CHECK-REL32: 00400074 g     F .text  {{[0-9a-f]+}} main
> +# CHECK-REL32: 00401000 g       .bss   {{[0-9a-f]+}} _myref
> +
> +# abs32.o
> +---
> +FileHeader:
> +  Class:           ELFCLASS32
> +  Data:            ELFDATA2LSB
> +  Type:            ET_REL
> +  Machine:         EM_ARM
> +  Flags:           [ EF_ARM_EABI_VER5 ]
> +Sections:
> +  - Name:            .text
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
> +    AddressAlign:    0x0000000000000004
> +    Content:         04B02DE500B08DE20030A0E30300A0E100D04BE204B09DE41EFF2FE1
> +  - Name:            .data
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_WRITE, SHF_ALLOC ]
> +    AddressAlign:    0x0000000000000004
> +    Content:         '10000000'
> +  - Name:            .rel.data
> +    Type:            SHT_REL
> +    Link:            .symtab
> +    AddressAlign:    0x0000000000000004
> +    Info:            .data
> +    Relocations:
> +      - Offset:          0x0000000000000000
> +        Symbol:          main
> +        Type:            R_ARM_TARGET1
> +        Addend:          0
> +  - Name:            .bss
> +    Type:            SHT_NOBITS
> +    Flags:           [ SHF_WRITE, SHF_ALLOC ]
> +    AddressAlign:    0x0000000000000001
> +    Content:         ''
> +Symbols:
> +  Global:
> +    - Name:            main
> +      Type:            STT_FUNC
> +      Section:         .text
> +      Size:            0x000000000000001C
> +    - Name:            data
> +      Type:            STT_OBJECT
> +      Section:         .data
> +      Size:            0x0000000000000004
> +# rel32.o
> +---
> +FileHeader:
> +  Class:           ELFCLASS32
> +  Data:            ELFDATA2LSB
> +  Type:            ET_REL
> +  Machine:         EM_ARM
> +  Flags:           [ EF_ARM_EABI_VER5 ]
> +Sections:
> +  - Name:            .text
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
> +    AddressAlign:    0x0000000000000004
> +    Content:         80B400AF0000FF0000231846BD465DF8047B7047
> +  - Name:            .rel.text
> +    Type:            SHT_REL
> +    Link:            .symtab
> +    AddressAlign:    0x0000000000000004
> +    Info:            .text
> +    Relocations:
> +      - Offset:          0x0000000000000004
> +        Symbol:          _myref
> +        Type:            R_ARM_TARGET1
> +  - Name:            .data
> +    Type:            SHT_PROGBITS
> +    Flags:           [ SHF_WRITE, SHF_ALLOC ]
> +    AddressAlign:    0x0000000000000001
> +    Content:         ''
> +  - Name:            .bss
> +    Type:            SHT_NOBITS
> +    Flags:           [ SHF_WRITE, SHF_ALLOC ]
> +    AddressAlign:    0x0000000000000004
> +    Content:         ''
> +Symbols:
> +  Global:
> +    - Name:            _myref
> +      Type:            STT_OBJECT
> +      Section:         .bss
> +      Size:            0x0000000000000004
> +    - Name:            main
> +      Type:            STT_FUNC
> +      Section:         .text
> +      Value:           0x0000000000000001
> +      Size:            0x0000000000000014
> +...
>
> Added: lld/trunk/test/elf/options/target-specific-args.test
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/options/target-specific-args.test?rev=234009&view=auto
> ==============================================================================
> --- lld/trunk/test/elf/options/target-specific-args.test (added)
> +++ lld/trunk/test/elf/options/target-specific-args.test Fri Apr  3 07:03:47 2015
> @@ -0,0 +1,5 @@
> +# Test of target specific options
> +# RUN: lld -flavor gnu -target x86_64 --arm-target1-rel \
> +# RUN: %p/../Inputs/foo.o.x86-64 --noinhibit-exec -o %t 2>&1 | FileCheck %s
> +
> +# CHECK: warning: ignoring unsupported ARM/ELF specific argument: --arm-target1-rel
>
>
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