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author | Dimitry Andric <dim@FreeBSD.org> | 2017-06-10 13:44:49 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2017-06-10 13:44:49 +0000 |
commit | 2079716dfb3fb7e4e24b8b2e85eb6780b981a0af (patch) | |
tree | 3b0c58e50948b450b50b20ae5a38c005128edfb5 /ELF/Relocations.cpp | |
parent | b9a1baec33e911ca24f51abf882d454e62047ea6 (diff) | |
download | src-2079716dfb3fb7e4e24b8b2e85eb6780b981a0af.tar.gz src-2079716dfb3fb7e4e24b8b2e85eb6780b981a0af.zip |
Vendor import of lld trunk r305145:vendor/lld/lld-trunk-r305145
Notes
Notes:
svn path=/vendor/lld/dist/; revision=319788
svn path=/vendor/lld/lld-trunk-r305145/; revision=319789; tag=vendor/lld/lld-trunk-r305145
Diffstat (limited to 'ELF/Relocations.cpp')
-rw-r--r-- | ELF/Relocations.cpp | 160 |
1 files changed, 99 insertions, 61 deletions
diff --git a/ELF/Relocations.cpp b/ELF/Relocations.cpp index 54cc6dd89d46..98c1349a2f0d 100644 --- a/ELF/Relocations.cpp +++ b/ELF/Relocations.cpp @@ -43,6 +43,7 @@ #include "Relocations.h" #include "Config.h" +#include "LinkerScript.h" #include "Memory.h" #include "OutputSections.h" #include "Strings.h" @@ -967,48 +968,51 @@ template <class ELFT> void elf::scanRelocations(InputSectionBase &S) { // in the Sections vector, and recalculate the InputSection output section // offsets. // This may invalidate any output section offsets stored outside of InputSection -void ThunkCreator::mergeThunks(OutputSection *OS, - std::vector<ThunkSection *> &Thunks) { - // Order Thunks in ascending OutSecOff - auto ThunkCmp = [](const ThunkSection *A, const ThunkSection *B) { - return A->OutSecOff < B->OutSecOff; - }; - std::stable_sort(Thunks.begin(), Thunks.end(), ThunkCmp); - - // Merge sorted vectors of Thunks and InputSections by OutSecOff - std::vector<InputSection *> Tmp; - Tmp.reserve(OS->Sections.size() + Thunks.size()); - auto MergeCmp = [](const InputSection *A, const InputSection *B) { - // std::merge requires a strict weak ordering. - if (A->OutSecOff < B->OutSecOff) - return true; - if (A->OutSecOff == B->OutSecOff) - // Check if Thunk is immediately before any specific Target InputSection - // for example Mips LA25 Thunks. - if (auto *TA = dyn_cast<ThunkSection>(A)) - if (TA && TA->getTargetInputSection() == B) - return true; - return false; - }; - std::merge(OS->Sections.begin(), OS->Sections.end(), Thunks.begin(), - Thunks.end(), std::back_inserter(Tmp), MergeCmp); - OS->Sections = std::move(Tmp); - OS->assignOffsets(); +void ThunkCreator::mergeThunks() { + for (auto &KV : ThunkSections) { + std::vector<InputSection *> *ISR = KV.first; + std::vector<ThunkSection *> &Thunks = KV.second; + + // Order Thunks in ascending OutSecOff + auto ThunkCmp = [](const ThunkSection *A, const ThunkSection *B) { + return A->OutSecOff < B->OutSecOff; + }; + std::stable_sort(Thunks.begin(), Thunks.end(), ThunkCmp); + + // Merge sorted vectors of Thunks and InputSections by OutSecOff + std::vector<InputSection *> Tmp; + Tmp.reserve(ISR->size() + Thunks.size()); + auto MergeCmp = [](const InputSection *A, const InputSection *B) { + // std::merge requires a strict weak ordering. + if (A->OutSecOff < B->OutSecOff) + return true; + if (A->OutSecOff == B->OutSecOff) + // Check if Thunk is immediately before any specific Target InputSection + // for example Mips LA25 Thunks. + if (auto *TA = dyn_cast<ThunkSection>(A)) + if (TA && TA->getTargetInputSection() == B) + return true; + return false; + }; + std::merge(ISR->begin(), ISR->end(), Thunks.begin(), Thunks.end(), + std::back_inserter(Tmp), MergeCmp); + *ISR = std::move(Tmp); + } } -ThunkSection *ThunkCreator::getOSThunkSec(ThunkSection *&TS, - OutputSection *OS) { - if (TS == nullptr) { +ThunkSection *ThunkCreator::getOSThunkSec(OutputSection *OS, + std::vector<InputSection *> *ISR) { + if (CurTS == nullptr) { uint32_t Off = 0; for (auto *IS : OS->Sections) { Off = IS->OutSecOff + IS->getSize(); if ((IS->Flags & SHF_EXECINSTR) == 0) break; } - TS = make<ThunkSection>(OS, Off); - ThunkSections[OS].push_back(TS); + CurTS = make<ThunkSection>(OS, Off); + ThunkSections[ISR].push_back(CurTS); } - return TS; + return CurTS; } ThunkSection *ThunkCreator::getISThunkSec(InputSection *IS, OutputSection *OS) { @@ -1017,7 +1021,21 @@ ThunkSection *ThunkCreator::getISThunkSec(InputSection *IS, OutputSection *OS) { return TS; auto *TOS = IS->getParent(); TS = make<ThunkSection>(TOS, IS->OutSecOff); - ThunkSections[TOS].push_back(TS); + + // Find InputSectionRange within TOS that IS is in + OutputSectionCommand *C = Script->getCmd(TOS); + std::vector<InputSection *> *Range = nullptr; + for (BaseCommand *BC : C->Commands) + if (auto *ISD = dyn_cast<InputSectionDescription> (BC)) { + InputSection *first = ISD->Sections.front(); + InputSection *last = ISD->Sections.back(); + if (IS->OutSecOff >= first->OutSecOff && + IS->OutSecOff <= last->OutSecOff) { + Range = &ISD->Sections; + break; + } + } + ThunkSections[Range].push_back(TS); ThunkedSections[IS] = TS; return TS; } @@ -1030,6 +1048,27 @@ std::pair<Thunk *, bool> ThunkCreator::getThunk(SymbolBody &Body, return std::make_pair(res.first->second, res.second); } +// Call Fn on every executable InputSection accessed via the linker script +// InputSectionDescription::Sections. +void ThunkCreator::forEachExecInputSection( + ArrayRef<OutputSectionCommand *> OutputSections, + std::function<void(OutputSection *, std::vector<InputSection *> *, + InputSection *)> + Fn) { + for (OutputSectionCommand *Cmd : OutputSections) { + OutputSection *OS = Cmd->Sec; + if (!(OS->Flags & SHF_ALLOC) || !(OS->Flags & SHF_EXECINSTR)) + continue; + if (OutputSectionCommand *C = Script->getCmd(OS)) + for (BaseCommand *BC : C->Commands) + if (auto *ISD = dyn_cast<InputSectionDescription>(BC)) { + CurTS = nullptr; + for (InputSection* IS : ISD->Sections) + Fn(OS, &ISD->Sections, IS); + } + } +} + // Process all relocations from the InputSections that have been assigned // to OutputSections and redirect through Thunks if needed. // @@ -1040,42 +1079,41 @@ std::pair<Thunk *, bool> ThunkCreator::getThunk(SymbolBody &Body, // // FIXME: All Thunks are assumed to be in range of the relocation. Range // extension Thunks are not yet supported. -bool ThunkCreator::createThunks(ArrayRef<OutputSection *> OutputSections) { +bool ThunkCreator::createThunks( + ArrayRef<OutputSectionCommand *> OutputSections) { // Create all the Thunks and insert them into synthetic ThunkSections. The // ThunkSections are later inserted back into the OutputSection. // We separate the creation of ThunkSections from the insertion of the // ThunkSections back into the OutputSection as ThunkSections are not always // inserted into the same OutputSection as the caller. - for (OutputSection *OS : OutputSections) { - ThunkSection *OSTS = nullptr; - for (InputSection *IS : OS->Sections) { - for (Relocation &Rel : IS->Relocations) { - SymbolBody &Body = *Rel.Sym; - if (!Target->needsThunk(Rel.Expr, Rel.Type, IS->File, Body)) - continue; - Thunk *T; - bool IsNew; - std::tie(T, IsNew) = getThunk(Body, Rel.Type); - if (IsNew) { - // Find or create a ThunkSection for the new Thunk - ThunkSection *TS; - if (auto *TIS = T->getTargetInputSection()) - TS = getISThunkSec(TIS, OS); - else - TS = getOSThunkSec(OSTS, OS); - TS->addThunk(T); + forEachExecInputSection( + OutputSections, [=](OutputSection *OS, std::vector<InputSection*> *ISR, + InputSection *IS) { + for (Relocation &Rel : IS->Relocations) { + SymbolBody &Body = *Rel.Sym; + if (!Target->needsThunk(Rel.Expr, Rel.Type, IS->File, Body)) + continue; + Thunk *T; + bool IsNew; + std::tie(T, IsNew) = getThunk(Body, Rel.Type); + if (IsNew) { + // Find or create a ThunkSection for the new Thunk + ThunkSection *TS; + if (auto *TIS = T->getTargetInputSection()) + TS = getISThunkSec(TIS, OS); + else + TS = getOSThunkSec(OS, ISR); + TS->addThunk(T); + } + // Redirect relocation to Thunk, we never go via the PLT to a Thunk + Rel.Sym = T->ThunkSym; + Rel.Expr = fromPlt(Rel.Expr); } - // Redirect relocation to Thunk, we never go via the PLT to a Thunk - Rel.Sym = T->ThunkSym; - Rel.Expr = fromPlt(Rel.Expr); - } - } - } + }); // Merge all created synthetic ThunkSections back into OutputSection - for (auto &KV : ThunkSections) - mergeThunks(KV.first, KV.second); + mergeThunks(); return !ThunkSections.empty(); } |