[DWARF][RISCV] Add support for RISC-V relocations needed for debug info
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
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 321e157..5ede9bf 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -1651,9 +1651,25 @@
//
// TODO Don't store Resolver in every RelocAddrEntry.
if (Supports && Supports(Reloc.getType())) {
- Map->try_emplace(Reloc.getOffset(),
- RelocAddrEntry{SymInfoOrErr->SectionIndex, Reloc,
- Resolver, SymInfoOrErr->Address});
+ auto I = Map->try_emplace(
+ Reloc.getOffset(),
+ RelocAddrEntry{SymInfoOrErr->SectionIndex, Reloc,
+ SymInfoOrErr->Address,
+ Optional<object::RelocationRef>(), 0, Resolver});
+ // If we didn't successfully insert that's because we already had a
+ // relocation for that offset. Store it as a second relocation in the
+ // same RelocAddrEntry instead.
+ if (!I.second) {
+ RelocAddrEntry &entry = I.first->getSecond();
+ if (entry.Reloc2) {
+ ErrorPolicy EP = HandleError(createError(
+ "At most two relocations per offset are supported"));
+ if (EP == ErrorPolicy::Halt)
+ return;
+ }
+ entry.Reloc2 = Reloc;
+ entry.SymbolValue2 = SymInfoOrErr->Address;
+ }
} else {
SmallString<32> Type;
Reloc.getTypeName(Type);
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
index 6f2f992..b9adf8c 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
@@ -24,7 +24,10 @@
return A;
if (SecNdx)
*SecNdx = E->SectionIndex;
- return E->Resolver(E->Reloc, E->SymbolValue, A);
+ uint64_t R = E->Resolver(E->Reloc, E->SymbolValue, A);
+ if (E->Reloc2)
+ R = E->Resolver(*E->Reloc2, E->SymbolValue2, R);
+ return R;
}
Optional<uint64_t>
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
index 3ee5652..a1cb1e8 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -300,7 +300,7 @@
const uint64_t PrologueOffset = *OffsetPtr;
clear();
- TotalLength = DebugLineData.getU32(OffsetPtr);
+ TotalLength = DebugLineData.getRelocatedValue(4, OffsetPtr);
if (TotalLength == UINT32_MAX) {
FormParams.Format = dwarf::DWARF64;
TotalLength = DebugLineData.getU64(OffsetPtr);
@@ -325,7 +325,8 @@
SegSelectorSize = DebugLineData.getU8(OffsetPtr);
}
- PrologueLength = DebugLineData.getUnsigned(OffsetPtr, sizeofPrologueLength());
+ PrologueLength =
+ DebugLineData.getRelocatedValue(sizeofPrologueLength(), OffsetPtr);
const uint64_t EndPrologueOffset = PrologueLength + *OffsetPtr;
MinInstLength = DebugLineData.getU8(OffsetPtr);
if (getVersion() >= 4)
@@ -754,7 +755,7 @@
// requires the use of DW_LNS_advance_pc. Such assemblers, however,
// can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
{
- uint16_t PCOffset = DebugLineData.getU16(OffsetPtr);
+ uint16_t PCOffset = DebugLineData.getRelocatedValue(2, OffsetPtr);
State.Row.Address.Address += PCOffset;
if (OS)
*OS
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
index b3e4c91..290d355 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
@@ -299,7 +299,7 @@
case DW_FORM_data8:
case DW_FORM_ref8:
case DW_FORM_ref_sup8:
- Value.uval = Data.getU64(OffsetPtr);
+ Value.uval = Data.getRelocatedValue(8, OffsetPtr);
break;
case DW_FORM_data16:
// Treat this like a 16-byte block.
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFListTable.cpp b/llvm/lib/DebugInfo/DWARF/DWARFListTable.cpp
index 32bb6d3..e38e706 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFListTable.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFListTable.cpp
@@ -25,7 +25,7 @@
"%s table length at offset 0x%" PRIx32,
SectionName.data(), *OffsetPtr);
// TODO: Add support for DWARF64.
- HeaderData.Length = Data.getU32(OffsetPtr);
+ HeaderData.Length = Data.getRelocatedValue(4, OffsetPtr);
if (HeaderData.Length == 0xffffffffu)
return createStringError(errc::not_supported,
"DWARF64 is not supported in %s at offset 0x%" PRIx32,
@@ -73,7 +73,7 @@
SectionName.data(), HeaderOffset, HeaderData.OffsetEntryCount);
Data.setAddressSize(HeaderData.AddrSize);
for (uint32_t I = 0; I < HeaderData.OffsetEntryCount; ++I)
- Offsets.push_back(Data.getU32(OffsetPtr));
+ Offsets.push_back(Data.getRelocatedValue(4, OffsetPtr));
return Error::success();
}
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 94bfc8c..b74acf6 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -241,7 +241,7 @@
IndexEntry = Entry;
if (!IndexEntry && Index)
IndexEntry = Index->getFromOffset(*offset_ptr);
- Length = debug_info.getU32(offset_ptr);
+ Length = debug_info.getRelocatedValue(4, offset_ptr);
FormParams.Format = DWARF32;
unsigned SizeOfLength = 4;
if (Length == 0xffffffff) {