44deaf7e54
When code relaxation is enabled many RISC-V fixups are not resolved but instead relocations are emitted. This happens even for DWARF debug sections. Therefore, to properly support the parsing of DWARF debug info we need to be able to resolve RISC-V relocations. This patch adds: * Support for RISC-V relocations in RelocationResolver * DWARF support for two relocations per object file offset * DWARF changes to support relocations in more DIE fields The two relocations per offset change is needed because some RISC-V relocations (used for label differences) come in pairs. Relocations can also be emitted for DWARF fields where relocations were not yet evaluated. Adding relocation support for some of these fields is essencial. On the other hand, LLVM currently emits RISC-V relocations for fixups that could be safely evaluated, since they can never be affected by code relaxations. This patch also adds relocation support for the fields affected by those extraneous relocations (the DWARF unit entry Length, and the DWARF debug line entry TotalLength and PrologueLength), for testing purposes. Differential Revision: https://reviews.llvm.org/D62062 Patch by Luís Marques. llvm-svn: 366402
100 lines
2.6 KiB
C++
100 lines
2.6 KiB
C++
//===- DWARFDataExtractor.cpp ---------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
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#include "llvm/BinaryFormat/Dwarf.h"
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#include "llvm/DebugInfo/DWARF/DWARFContext.h"
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using namespace llvm;
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uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
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uint64_t *SecNdx) const {
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if (SecNdx)
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*SecNdx = object::SectionedAddress::UndefSection;
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if (!Section)
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return getUnsigned(Off, Size);
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Optional<RelocAddrEntry> E = Obj->find(*Section, *Off);
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uint64_t A = getUnsigned(Off, Size);
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if (!E)
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return A;
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if (SecNdx)
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*SecNdx = E->SectionIndex;
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uint64_t R = E->Resolver(E->Reloc, E->SymbolValue, A);
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if (E->Reloc2)
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R = E->Resolver(*E->Reloc2, E->SymbolValue2, R);
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return R;
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}
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Optional<uint64_t>
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DWARFDataExtractor::getEncodedPointer(uint32_t *Offset, uint8_t Encoding,
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uint64_t PCRelOffset) const {
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if (Encoding == dwarf::DW_EH_PE_omit)
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return None;
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uint64_t Result = 0;
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uint32_t OldOffset = *Offset;
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// First get value
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switch (Encoding & 0x0F) {
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case dwarf::DW_EH_PE_absptr:
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switch (getAddressSize()) {
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case 2:
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case 4:
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case 8:
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Result = getUnsigned(Offset, getAddressSize());
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break;
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default:
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return None;
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}
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break;
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case dwarf::DW_EH_PE_uleb128:
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Result = getULEB128(Offset);
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break;
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case dwarf::DW_EH_PE_sleb128:
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Result = getSLEB128(Offset);
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break;
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case dwarf::DW_EH_PE_udata2:
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Result = getUnsigned(Offset, 2);
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break;
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case dwarf::DW_EH_PE_udata4:
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Result = getUnsigned(Offset, 4);
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break;
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case dwarf::DW_EH_PE_udata8:
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Result = getUnsigned(Offset, 8);
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break;
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case dwarf::DW_EH_PE_sdata2:
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Result = getSigned(Offset, 2);
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break;
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case dwarf::DW_EH_PE_sdata4:
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Result = getSigned(Offset, 4);
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break;
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case dwarf::DW_EH_PE_sdata8:
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Result = getSigned(Offset, 8);
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break;
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default:
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return None;
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}
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// Then add relative offset, if required
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switch (Encoding & 0x70) {
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case dwarf::DW_EH_PE_absptr:
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// do nothing
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break;
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case dwarf::DW_EH_PE_pcrel:
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Result += PCRelOffset;
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break;
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case dwarf::DW_EH_PE_datarel:
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case dwarf::DW_EH_PE_textrel:
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case dwarf::DW_EH_PE_funcrel:
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case dwarf::DW_EH_PE_aligned:
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default:
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*Offset = OldOffset;
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return None;
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}
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return Result;
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}
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