[llvm-branch-commits] [llvm] 094d638 - [RelocationResolver] Support R_PPC_REL32 & R_PPC64_REL{32, 64}

[Hans Wennborg via llvm-branch-commits]

This seems fine, but in general please always check with me before
pushing to the release branch. (Same for a1f2fd1.)

Thanks,
Hans

On Sun, Jul 19, 2020 at 12:22 AM Fangrui Song via llvm-branch-commits
<llvm-branch-commits at lists.llvm.org> wrote:
>
>
> Author: Fangrui Song
> Date: 2020-07-18T15:20:30-07:00
> New Revision: 094d6386ec0478076218303a756edda8a63d7c55
>
> URL: https://github.com/llvm/llvm-project/commit/094d6386ec0478076218303a756edda8a63d7c55
> DIFF: https://github.com/llvm/llvm-project/commit/094d6386ec0478076218303a756edda8a63d7c55.diff
>
> LOG: [RelocationResolver] Support R_PPC_REL32 & R_PPC64_REL{32,64}
>
> This suppresses `failed to compute relocation: R_PPC_REL32, Invalid data was encountered while parsing the file`
> and its 64-bit variants when running llvm-dwarfdump on a PowerPC object file with .eh_frame
>
> Unfortunately it is difficult to test the computation:
> DWARFDataExtractor::getEncodedPointer does not use the relocated value
> and even if it does, we need to teach llvm-dwarfdump --eh-frame to do
> some linker job to report a reasonable address.
>
> (cherry picked from commit b922004ea29d54534c4f09b9cfa655bf5f3360f0)
>
> Added:
>     llvm/test/DebugInfo/PowerPC/eh-frame.ll
>
> Modified:
>     llvm/lib/Object/RelocationResolver.cpp
>
> Removed:
>
>
>
> ################################################################################
> diff  --git a/llvm/lib/Object/RelocationResolver.cpp b/llvm/lib/Object/RelocationResolver.cpp
> index 3f3f79b0f4ff..0058d12dcc87 100644
> --- a/llvm/lib/Object/RelocationResolver.cpp
> +++ b/llvm/lib/Object/RelocationResolver.cpp
> @@ -152,6 +152,8 @@ static bool supportsPPC64(uint64_t Type) {
>    switch (Type) {
>    case ELF::R_PPC64_ADDR32:
>    case ELF::R_PPC64_ADDR64:
> +  case ELF::R_PPC64_REL32:
> +  case ELF::R_PPC64_REL64:
>      return true;
>    default:
>      return false;
> @@ -164,6 +166,10 @@ static uint64_t resolvePPC64(RelocationRef R, uint64_t S, uint64_t A) {
>      return (S + getELFAddend(R)) & 0xFFFFFFFF;
>    case ELF::R_PPC64_ADDR64:
>      return S + getELFAddend(R);
> +  case ELF::R_PPC64_REL32:
> +    return (S + getELFAddend(R) - R.getOffset()) & 0xFFFFFFFF;
> +  case ELF::R_PPC64_REL64:
> +    return S + getELFAddend(R) - R.getOffset();
>    default:
>      llvm_unreachable("Invalid relocation type");
>    }
> @@ -259,12 +265,22 @@ static uint64_t resolveX86(RelocationRef R, uint64_t S, uint64_t A) {
>  }
>
>  static bool supportsPPC32(uint64_t Type) {
> -  return Type == ELF::R_PPC_ADDR32;
> +  switch (Type) {
> +  case ELF::R_PPC_ADDR32:
> +  case ELF::R_PPC_REL32:
> +    return true;
> +  default:
> +    return false;
> +  }
>  }
>
>  static uint64_t resolvePPC32(RelocationRef R, uint64_t S, uint64_t A) {
> -  if (R.getType() == ELF::R_PPC_ADDR32)
> +  switch (R.getType()) {
> +  case ELF::R_PPC_ADDR32:
>      return (S + getELFAddend(R)) & 0xFFFFFFFF;
> +  case ELF::R_PPC_REL32:
> +    return (S + getELFAddend(R) - R.getOffset()) & 0xFFFFFFFF;
> +  }
>    llvm_unreachable("Invalid relocation type");
>  }
>
>
> diff  --git a/llvm/test/DebugInfo/PowerPC/eh-frame.ll b/llvm/test/DebugInfo/PowerPC/eh-frame.ll
> new file mode 100644
> index 000000000000..3a8f7df6b61a
> --- /dev/null
> +++ b/llvm/test/DebugInfo/PowerPC/eh-frame.ll
> @@ -0,0 +1,39 @@
> +; RUN: llc -filetype=obj -mtriple=powerpc %s -o %t32.o
> +; RUN: llvm-readobj -r %t32.o | FileCheck %s --check-prefix=PPC_REL
> +; RUN: llvm-dwarfdump --eh-frame %t32.o 2>&1 | FileCheck %s --check-prefix=PPC
> +
> +; PPC_REL:      R_PPC_REL32 .text 0x0
> +; PPC_REL-NEXT: R_PPC_REL32 .text 0x4
> +
> +; PPC-NOT: warning:
> +; PPC: FDE cie=00000000 pc=00000000...00000004
> +;; TODO Take relocation into consideration
> +; PPC: FDE cie=00000000 pc=00000000...00000004
> +
> +; RUN: llc -filetype=obj -mtriple=ppc64 %s -o %t64.o
> +; RUN: llvm-readobj -r %t64.o | FileCheck %s --check-prefix=PPC64_REL
> +; RUN: llvm-dwarfdump --eh-frame %t64.o 2>&1 | FileCheck %s --check-prefix=PPC64
> +
> +; PPC64_REL:      R_PPC64_REL32 .text 0x0
> +; PPC64_REL-NEXT: R_PPC64_REL32 .text 0x10
> +
> +; PPC64-NOT: warning:
> +; PPC64: FDE cie=00000000 pc=00000000...00000010
> +; PPC64: FDE cie=00000000 pc=00000000...00000010
> +
> +; RUN: llc -filetype=obj -mtriple=ppc64le -code-model=large %s -o %t64l.o
> +; RUN: llvm-readobj -r %t64l.o | FileCheck %s --check-prefix=PPC64L_REL
> +; RUN: llvm-dwarfdump --eh-frame %t64l.o 2>&1 | FileCheck %s --check-prefix=PPC64
> +
> +; PPC64L_REL:      R_PPC64_REL64 .text 0x0
> +; PPC64L_REL-NEXT: R_PPC64_REL64 .text 0x10
> +
> +define void @foo() {
> +entry:
> +  ret void
> +}
> +
> +define void @bar() {
> +entry:
> +  ret void
> +}
>
>
>
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