[lld] r230191 - [ELF] Add symbol to ELFReference.
Rui Ueyama
ruiu at google.com
Mon Feb 23 10:31:42 PST 2015
My point is that usually when you want to know the name of a symbol to
which a reference is pointing, you'd do ref->getTarget()->name() instead of
adding a name to a reference. In LLD's model, symbol name is a property of
the node (atom) and not a property of edge (reference).
My question is that why you had to add a name to the reference, instead of
using the usual way? What's special about the feature that you were trying
to implement?
On Mon, Feb 23, 2015 at 4:59 AM, Shankar Easwaran <shankare at codeaurora.org>
wrote:
> Hi Rui,
>
> Thanks for the review.
>
> This is used to lookup the symbol/section, for a reference.
>
> This is used to check if the symbol/section that points to the reference
> is from outside the group (or) not in the same section group.
>
> More details are here FYI. https://mentorembedded.github.
> io/cxx-abi/abi/prop-72-comdat.html
>
> Shankar Easwaran
>
>
> On 2/22/2015 9:34 PM, Rui Ueyama wrote:
>
>> This patch looks really weird. Basically in the atom model a reference is
>> a
>> relocation, and an atom is a symbol + data. However, looks like this patch
>> made a reference to have an item that it is pointing to. If so, that
>> doesn't sound correct.
>>
>> Send this kind of nontrivial changes to pre-commit review first, please.
>>
>> On Sun, Feb 22, 2015 at 3:46 PM, Shankar Easwaran <
>> shankare at codeaurora.org>
>> wrote:
>>
>> Author: shankare
>>> Date: Sun Feb 22 17:46:21 2015
>>> New Revision: 230191
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=230191&view=rev
>>> Log:
>>> [ELF] Add symbol to ELFReference.
>>>
>>> Relocation handling need more information about the Symbol that we are
>>> creating
>>> references for.
>>>
>>> No change in functionality.
>>>
>>> Modified:
>>> lld/trunk/lib/ReaderWriter/ELF/Atoms.h
>>> lld/trunk/lib/ReaderWriter/ELF/ELFFile.h
>>> lld/trunk/lib/ReaderWriter/ELF/Mips/MipsELFFile.h
>>>
>>> Modified: lld/trunk/lib/ReaderWriter/ELF/Atoms.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/
>>> ReaderWriter/ELF/Atoms.h?rev=230191&r1=230190&r2=230191&view=diff
>>>
>>> ============================================================
>>> ==================
>>> --- lld/trunk/lib/ReaderWriter/ELF/Atoms.h (original)
>>> +++ lld/trunk/lib/ReaderWriter/ELF/Atoms.h Sun Feb 22 17:46:21 2015
>>> @@ -35,23 +35,27 @@ template <typename ELFT> class ELFFile;
>>> template <class ELFT> class ELFReference : public Reference {
>>> typedef llvm::object::Elf_Rel_Impl<ELFT, false> Elf_Rel;
>>> typedef llvm::object::Elf_Rel_Impl<ELFT, true> Elf_Rela;
>>> + typedef llvm::object::Elf_Sym_Impl<ELFT> Elf_Sym;
>>> +
>>> public:
>>> - ELFReference(const Elf_Rela *rela, uint64_t off, Reference::KindArch
>>> arch,
>>> - Reference::KindValue relocType, uint32_t idx)
>>> - : Reference(Reference::KindNamespace::ELF, arch, relocType),
>>> + ELFReference(const Elf_Sym *sym, const Elf_Rela *rela, uint64_t off,
>>> + Reference::KindArch arch, Reference::KindValue relocType,
>>> + uint32_t idx)
>>> + : Reference(Reference::KindNamespace::ELF, arch, relocType),
>>> _sym(sym),
>>> _target(nullptr), _targetSymbolIndex(idx), _offsetInAtom(off),
>>> _addend(rela->r_addend) {}
>>>
>>> - ELFReference(uint64_t off, Reference::KindArch arch,
>>> + ELFReference(const Elf_Sym *sym, uint64_t off, Reference::KindArch
>>> arch,
>>> Reference::KindValue relocType, uint32_t idx)
>>> - : Reference(Reference::KindNamespace::ELF, arch, relocType),
>>> + : Reference(Reference::KindNamespace::ELF, arch, relocType),
>>> _sym(sym),
>>> _target(nullptr), _targetSymbolIndex(idx), _offsetInAtom(off),
>>> _addend(0) {}
>>>
>>> ELFReference(uint32_t edgeKind)
>>> : Reference(Reference::KindNamespace::all,
>>> Reference::KindArch::all,
>>> edgeKind),
>>> - _target(nullptr), _targetSymbolIndex(0), _offsetInAtom(0),
>>> _addend(0) {}
>>> + _sym(nullptr), _target(nullptr), _targetSymbolIndex(0),
>>> + _offsetInAtom(0), _addend(0) {}
>>>
>>> uint64_t offsetInAtom() const override { return _offsetInAtom; }
>>>
>>> @@ -70,7 +74,10 @@ public:
>>>
>>> void setTarget(const Atom *newAtom) override { _target = newAtom; }
>>>
>>> + const Elf_Sym *symbol() const { return _sym; }
>>> +
>>> private:
>>> + const Elf_Sym *_sym;
>>> const Atom *_target;
>>> uint64_t _targetSymbolIndex;
>>> uint64_t _offsetInAtom;
>>>
>>> Modified: lld/trunk/lib/ReaderWriter/ELF/ELFFile.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/
>>> ReaderWriter/ELF/ELFFile.h?rev=230191&r1=230190&r2=230191&view=diff
>>>
>>> ============================================================
>>> ==================
>>> --- lld/trunk/lib/ReaderWriter/ELF/ELFFile.h (original)
>>> +++ lld/trunk/lib/ReaderWriter/ELF/ELFFile.h Sun Feb 22 17:46:21 2015
>>> @@ -181,12 +181,12 @@ protected:
>>> std::error_code doParse() override;
>>>
>>> /// \brief Iterate over Elf_Rela relocations list and create
>>> references.
>>> - virtual void createRelocationReferences(const Elf_Sym &symbol,
>>> + virtual void createRelocationReferences(const Elf_Sym *symbol,
>>> ArrayRef<uint8_t> content,
>>> range<Elf_Rela_Iter> rels);
>>>
>>> /// \brief Iterate over Elf_Rel relocations list and create
>>> references.
>>> - virtual void createRelocationReferences(const Elf_Sym &symbol,
>>> + virtual void createRelocationReferences(const Elf_Sym *symbol,
>>> ArrayRef<uint8_t> symContent,
>>> ArrayRef<uint8_t> secContent,
>>> range<Elf_Rel_Iter> rels);
>>> @@ -796,12 +796,12 @@ ELFDefinedAtom<ELFT> *ELFFile<ELFT>::cre
>>> // Add Rela (those with r_addend) references:
>>> auto rari = _relocationAddendReferences.find(sectionName);
>>> if (rari != _relocationAddendReferences.end())
>>> - createRelocationReferences(*symbol, symContent, rari->second);
>>> + createRelocationReferences(symbol, symContent, rari->second);
>>>
>>> // Add Rel references.
>>> auto rri = _relocationReferences.find(sectionName);
>>> if (rri != _relocationReferences.end())
>>> - createRelocationReferences(*symbol, symContent, secContent,
>>> rri->second);
>>> + createRelocationReferences(symbol, symContent, secContent,
>>> rri->second);
>>>
>>> // Create the DefinedAtom and add it to the list of DefinedAtoms.
>>> return *handleDefinedSymbol(symbolName, sectionName, symbol,
>>> section,
>>> @@ -810,35 +810,35 @@ ELFDefinedAtom<ELFT> *ELFFile<ELFT>::cre
>>> }
>>>
>>> template <class ELFT>
>>> -void ELFFile<ELFT>::createRelocationReferences(const Elf_Sym &symbol,
>>> +void ELFFile<ELFT>::createRelocationReferences(const Elf_Sym *symbol,
>>> ArrayRef<uint8_t>
>>> content,
>>> range<Elf_Rela_Iter>
>>> rels)
>>> {
>>> bool isMips64EL = _objFile->isMips64EL();
>>> - const auto symValue = getSymbolValue(&symbol);
>>> + const auto symValue = getSymbolValue(symbol);
>>> for (const auto &rel : rels) {
>>> if (rel.r_offset < symValue ||
>>> symValue + content.size() <= rel.r_offset)
>>> continue;
>>> _references.push_back(new (_readerStorage) ELFReference<ELFT>(
>>> - &rel, rel.r_offset - symValue, kindArch(),
>>> + symbol, &rel, rel.r_offset - symValue, kindArch(),
>>> rel.getType(isMips64EL), rel.getSymbol(isMips64EL)));
>>> }
>>> }
>>>
>>> template <class ELFT>
>>> -void ELFFile<ELFT>::createRelocationReferences(const Elf_Sym &symbol,
>>> +void ELFFile<ELFT>::createRelocationReferences(const Elf_Sym *symbol,
>>> ArrayRef<uint8_t>
>>> symContent,
>>> ArrayRef<uint8_t>
>>> secContent,
>>> range<Elf_Rel_Iter>
>>> rels) {
>>> bool isMips64EL = _objFile->isMips64EL();
>>> - const auto symValue = getSymbolValue(&symbol);
>>> + const auto symValue = getSymbolValue(symbol);
>>> for (const auto &rel : rels) {
>>> if (rel.r_offset < symValue ||
>>> symValue + symContent.size() <= rel.r_offset)
>>> continue;
>>> _references.push_back(new (_readerStorage) ELFReference<ELFT>(
>>> - rel.r_offset - symValue, kindArch(),
>>> - rel.getType(isMips64EL), rel.getSymbol(isMips64EL)));
>>> + symbol, rel.r_offset - symValue, kindArch(),
>>> rel.getType(isMips64EL),
>>> + rel.getSymbol(isMips64EL)));
>>> int32_t addend = *(symContent.data() + rel.r_offset - symValue);
>>> _references.back()->setAddend(addend);
>>> }
>>>
>>> Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsELFFile.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/
>>> MipsELFFile.h?rev=230191&r1=230190&r2=230191&view=diff
>>>
>>> ============================================================
>>> ==================
>>> --- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsELFFile.h (original)
>>> +++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsELFFile.h Sun Feb 22
>>> 17:46:21
>>> 2015
>>> @@ -199,17 +199,17 @@ private:
>>> return std::error_code();
>>> }
>>>
>>> - void createRelocationReferences(const Elf_Sym &symbol,
>>> + void createRelocationReferences(const Elf_Sym *symbol,
>>> ArrayRef<uint8_t> symContent,
>>> ArrayRef<uint8_t> secContent,
>>> range<Elf_Rel_Iter> rels) override {
>>> for (Elf_Rel_Iter rit = rels.begin(), eit = rels.end(); rit != eit;
>>> ++rit) {
>>> - if (rit->r_offset < symbol.st_value ||
>>> - symbol.st_value + symContent.size() <= rit->r_offset)
>>> + if (rit->r_offset < symbol->st_value ||
>>> + symbol->st_value + symContent.size() <= rit->r_offset)
>>> continue;
>>>
>>> this->_references.push_back(new (this->_readerStorage)
>>> ELFReference<ELFT>(
>>> - rit->r_offset - symbol.st_value, this->kindArch(),
>>> + symbol, rit->r_offset - symbol->st_value, this->kindArch(),
>>> rit->getType(isMips64EL()), rit->getSymbol(isMips64EL())));
>>>
>>> auto addend = getAddend(*rit, secContent);
>>>
>>>
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>
>>>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted
> by the Linux Foundation
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150223/269fc2f4/attachment.html>
More information about the llvm-commits
mailing list