Commit Graph

3 Commits

Author SHA1 Message Date
Kazu Hirata
c92524272b [llvm] Fix header guards (NFC)
Identified with llvm-header-guard.
2021-02-05 21:02:06 -08:00
Georgii Rymar
49ab0f3272 [lib/Object] - Generalize the RelocationResolver API.
This allows to reuse the RelocationResolver from the code
that doesn't want to deal with `RelocationRef` class.

I am going to use it in llvm-readobj. See the description
of D91530 for more details.

Differential revision: https://reviews.llvm.org/D91533
2020-11-20 10:32:49 +03:00
Fangrui Song
72e7abe0f8 [DWARF] Refactor RelocVisitor and fix computation of SHT_RELA-typed relocation entries
Summary:
getRelocatedValue may compute incorrect value for SHT_RELA-typed relocation entries.

// DWARFDataExtractor.cpp
uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
...
  // This formula is correct for REL, but may be incorrect for RELA if the value
  // stored in the location (getUnsigned(Off, Size)) is not zero.
  return getUnsigned(Off, Size) + Rel->Value;

In this patch, we

* refactor these visit* functions to include a new parameter `uint64_t A`.
  Since these visit* functions are no longer used as visitors, rename them to resolve*.
  + REL: A is used as the addend. A is the value stored in the location where the
    relocation applies: getUnsigned(Off, Size)
  + RELA: The addend encoded in RelocationRef is used, e.g. getELFAddend(R)
* and add another set of supports* functions to check if a given relocation type is handled.
  DWARFObjInMemory uses them to fail early.

Reviewers: echristo, dblaikie

Reviewed By: echristo

Subscribers: mgorny, aprantl, aheejin, fedor.sergeev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57939

llvm-svn: 356729
2019-03-22 02:43:11 +00:00