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authorpatrick <patrick@openbsd.org>2020-08-03 15:06:44 +0000
committerpatrick <patrick@openbsd.org>2020-08-03 15:06:44 +0000
commitb64793999546ed8adebaeebd9d8345d18db8927d (patch)
tree4357c27b561d73b0e089727c6ed659f2ceff5f47 /gnu/llvm/tools/lld/ELF/EhFrame.cpp
parentAdd support for UTF-8 DISPLAY-HINTs with octet length. For now only (diff)
downloadwireguard-openbsd-b64793999546ed8adebaeebd9d8345d18db8927d.tar.xz
wireguard-openbsd-b64793999546ed8adebaeebd9d8345d18db8927d.zip
Remove LLVM 8.0.1 files.
Diffstat (limited to 'gnu/llvm/tools/lld/ELF/EhFrame.cpp')
-rw-r--r--gnu/llvm/tools/lld/ELF/EhFrame.cpp198
1 files changed, 0 insertions, 198 deletions
diff --git a/gnu/llvm/tools/lld/ELF/EhFrame.cpp b/gnu/llvm/tools/lld/ELF/EhFrame.cpp
deleted file mode 100644
index 95d444bdc2a..00000000000
--- a/gnu/llvm/tools/lld/ELF/EhFrame.cpp
+++ /dev/null
@@ -1,198 +0,0 @@
-//===- EhFrame.cpp -------------------------------------------------------===//
-//
-// The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// .eh_frame section contains information on how to unwind the stack when
-// an exception is thrown. The section consists of sequence of CIE and FDE
-// records. The linker needs to merge CIEs and associate FDEs to CIEs.
-// That means the linker has to understand the format of the section.
-//
-// This file contains a few utility functions to read .eh_frame contents.
-//
-//===----------------------------------------------------------------------===//
-
-#include "EhFrame.h"
-#include "Config.h"
-#include "InputSection.h"
-#include "Relocations.h"
-#include "Target.h"
-#include "lld/Common/ErrorHandler.h"
-#include "lld/Common/Strings.h"
-#include "llvm/BinaryFormat/Dwarf.h"
-#include "llvm/Object/ELF.h"
-
-using namespace llvm;
-using namespace llvm::ELF;
-using namespace llvm::dwarf;
-using namespace llvm::object;
-
-using namespace lld;
-using namespace lld::elf;
-
-namespace {
-class EhReader {
-public:
- EhReader(InputSectionBase *S, ArrayRef<uint8_t> D) : IS(S), D(D) {}
- size_t readEhRecordSize();
- uint8_t getFdeEncoding();
-
-private:
- template <class P> void failOn(const P *Loc, const Twine &Msg) {
- fatal("corrupted .eh_frame: " + Msg + "\n>>> defined in " +
- IS->getObjMsg((const uint8_t *)Loc - IS->data().data()));
- }
-
- uint8_t readByte();
- void skipBytes(size_t Count);
- StringRef readString();
- void skipLeb128();
- void skipAugP();
-
- InputSectionBase *IS;
- ArrayRef<uint8_t> D;
-};
-}
-
-size_t elf::readEhRecordSize(InputSectionBase *S, size_t Off) {
- return EhReader(S, S->data().slice(Off)).readEhRecordSize();
-}
-
-// .eh_frame section is a sequence of records. Each record starts with
-// a 4 byte length field. This function reads the length.
-size_t EhReader::readEhRecordSize() {
- if (D.size() < 4)
- failOn(D.data(), "CIE/FDE too small");
-
- // First 4 bytes of CIE/FDE is the size of the record.
- // If it is 0xFFFFFFFF, the next 8 bytes contain the size instead,
- // but we do not support that format yet.
- uint64_t V = read32(D.data());
- if (V == UINT32_MAX)
- failOn(D.data(), "CIE/FDE too large");
- uint64_t Size = V + 4;
- if (Size > D.size())
- failOn(D.data(), "CIE/FDE ends past the end of the section");
- return Size;
-}
-
-// Read a byte and advance D by one byte.
-uint8_t EhReader::readByte() {
- if (D.empty())
- failOn(D.data(), "unexpected end of CIE");
- uint8_t B = D.front();
- D = D.slice(1);
- return B;
-}
-
-void EhReader::skipBytes(size_t Count) {
- if (D.size() < Count)
- failOn(D.data(), "CIE is too small");
- D = D.slice(Count);
-}
-
-// Read a null-terminated string.
-StringRef EhReader::readString() {
- const uint8_t *End = std::find(D.begin(), D.end(), '\0');
- if (End == D.end())
- failOn(D.data(), "corrupted CIE (failed to read string)");
- StringRef S = toStringRef(D.slice(0, End - D.begin()));
- D = D.slice(S.size() + 1);
- return S;
-}
-
-// Skip an integer encoded in the LEB128 format.
-// Actual number is not of interest because only the runtime needs it.
-// But we need to be at least able to skip it so that we can read
-// the field that follows a LEB128 number.
-void EhReader::skipLeb128() {
- const uint8_t *ErrPos = D.data();
- while (!D.empty()) {
- uint8_t Val = D.front();
- D = D.slice(1);
- if ((Val & 0x80) == 0)
- return;
- }
- failOn(ErrPos, "corrupted CIE (failed to read LEB128)");
-}
-
-static size_t getAugPSize(unsigned Enc) {
- switch (Enc & 0x0f) {
- case DW_EH_PE_absptr:
- case DW_EH_PE_signed:
- return Config->Wordsize;
- case DW_EH_PE_udata2:
- case DW_EH_PE_sdata2:
- return 2;
- case DW_EH_PE_udata4:
- case DW_EH_PE_sdata4:
- return 4;
- case DW_EH_PE_udata8:
- case DW_EH_PE_sdata8:
- return 8;
- }
- return 0;
-}
-
-void EhReader::skipAugP() {
- uint8_t Enc = readByte();
- if ((Enc & 0xf0) == DW_EH_PE_aligned)
- failOn(D.data() - 1, "DW_EH_PE_aligned encoding is not supported");
- size_t Size = getAugPSize(Enc);
- if (Size == 0)
- failOn(D.data() - 1, "unknown FDE encoding");
- if (Size >= D.size())
- failOn(D.data() - 1, "corrupted CIE");
- D = D.slice(Size);
-}
-
-uint8_t elf::getFdeEncoding(EhSectionPiece *P) {
- return EhReader(P->Sec, P->data()).getFdeEncoding();
-}
-
-uint8_t EhReader::getFdeEncoding() {
- skipBytes(8);
- int Version = readByte();
- if (Version != 1 && Version != 3)
- failOn(D.data() - 1,
- "FDE version 1 or 3 expected, but got " + Twine(Version));
-
- StringRef Aug = readString();
-
- // Skip code and data alignment factors.
- skipLeb128();
- skipLeb128();
-
- // Skip the return address register. In CIE version 1 this is a single
- // byte. In CIE version 3 this is an unsigned LEB128.
- if (Version == 1)
- readByte();
- else
- skipLeb128();
-
- // We only care about an 'R' value, but other records may precede an 'R'
- // record. Unfortunately records are not in TLV (type-length-value) format,
- // so we need to teach the linker how to skip records for each type.
- for (char C : Aug) {
- if (C == 'R')
- return readByte();
- if (C == 'z') {
- skipLeb128();
- continue;
- }
- if (C == 'P') {
- skipAugP();
- continue;
- }
- if (C == 'L') {
- readByte();
- continue;
- }
- failOn(Aug.data(), "unknown .eh_frame augmentation string: " + Aug);
- }
- return DW_EH_PE_absptr;
-}