[lld] r307867 - Refactor gdb index creation.
Rafael Espindola via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 12 16:56:53 PDT 2017
Author: rafael
Date: Wed Jul 12 16:56:53 2017
New Revision: 307867
URL: http://llvm.org/viewvc/llvm-project?rev=307867&view=rev
Log:
Refactor gdb index creation.
I have a patch to let DwarfContext defer to lld for getting section
contents and relocations.
That is a pretty big performance improvement.
This is just a refactoring to make that easier to do.
This change makes the *creation* of gdb index a dedicated step and
makes that templated. That is so that we can uses Elf_Rel in the code.
Modified:
lld/trunk/ELF/GdbIndex.h
lld/trunk/ELF/SyntheticSections.cpp
lld/trunk/ELF/SyntheticSections.h
lld/trunk/ELF/Writer.cpp
Modified: lld/trunk/ELF/GdbIndex.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/GdbIndex.h?rev=307867&r1=307866&r2=307867&view=diff
==============================================================================
--- lld/trunk/ELF/GdbIndex.h (original)
+++ lld/trunk/ELF/GdbIndex.h Wed Jul 12 16:56:53 2017
@@ -45,6 +45,7 @@ struct NameTypeEntry {
// debug information performed. That information futher used
// for filling gdb index section areas.
struct GdbIndexChunk {
+ InputSection *DebugInfoSec;
std::vector<AddressEntry> AddressArea;
std::vector<CompilationUnitEntry> CompilationUnits;
std::vector<NameTypeEntry> NamesAndTypes;
Modified: lld/trunk/ELF/SyntheticSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp?rev=307867&r1=307866&r2=307867&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp (original)
+++ lld/trunk/ELF/SyntheticSections.cpp Wed Jul 12 16:56:53 2017
@@ -1700,9 +1700,9 @@ unsigned PltSection::getPltRelocOff() co
return (HeaderSize == 0) ? InX::Plt->getSize() : 0;
}
-GdbIndexSection::GdbIndexSection()
+GdbIndexSection::GdbIndexSection(std::vector<GdbIndexChunk> &&Chunks)
: SyntheticSection(0, SHT_PROGBITS, 1, ".gdb_index"),
- StringPool(llvm::StringTableBuilder::ELF) {}
+ StringPool(llvm::StringTableBuilder::ELF), Chunks(std::move(Chunks)) {}
// Iterative hash function for symbol's name is described in .gdb_index format
// specification. Note that we use one for version 5 to 7 here, it is different
@@ -1714,11 +1714,10 @@ static uint32_t hash(StringRef Str) {
return R;
}
-static std::vector<CompilationUnitEntry> readCuList(DWARFContext &Dwarf,
- InputSection *Sec) {
+static std::vector<CompilationUnitEntry> readCuList(DWARFContext &Dwarf) {
std::vector<CompilationUnitEntry> Ret;
for (std::unique_ptr<DWARFCompileUnit> &CU : Dwarf.compile_units())
- Ret.push_back({Sec->OutSecOff + CU->getOffset(), CU->getLength() + 4});
+ Ret.push_back({CU->getOffset(), CU->getLength() + 4});
return Ret;
}
@@ -1765,19 +1764,15 @@ static std::vector<InputSection *> getDe
std::vector<InputSection *> Ret;
for (InputSectionBase *S : InputSections)
if (InputSection *IS = dyn_cast<InputSection>(S))
- if (IS->getParent() && IS->Name == ".debug_info")
+ if (IS->Name == ".debug_info")
Ret.push_back(IS);
return Ret;
}
void GdbIndexSection::buildIndex() {
- std::vector<InputSection *> V = getDebugInfoSections();
- if (V.empty())
+ if (Chunks.empty())
return;
- for (InputSection *Sec : V)
- Chunks.push_back(readDwarf(Sec));
-
uint32_t CuId = 0;
for (GdbIndexChunk &D : Chunks) {
for (AddressEntry &E : D.AddressArea)
@@ -1803,27 +1798,33 @@ void GdbIndexSection::buildIndex() {
}
}
-GdbIndexChunk GdbIndexSection::readDwarf(InputSection *Sec) {
- Expected<std::unique_ptr<object::ObjectFile>> Obj =
- object::ObjectFile::createObjectFile(Sec->File->MB);
- if (!Obj) {
- error(toString(Sec->File) + ": error creating DWARF context");
- return {};
- }
-
- DWARFContextInMemory Dwarf(*Obj.get(), nullptr, [&](Error E) {
- error(toString(Sec->File) + ": error parsing DWARF data:\n>>> " +
- toString(std::move(E)));
- return ErrorPolicy::Continue;
- });
-
+static GdbIndexChunk readDwarf(DWARFContextInMemory &Dwarf, InputSection *Sec) {
GdbIndexChunk Ret;
- Ret.CompilationUnits = readCuList(Dwarf, Sec);
+ Ret.DebugInfoSec = Sec;
+ Ret.CompilationUnits = readCuList(Dwarf);
Ret.AddressArea = readAddressArea(Dwarf, Sec);
Ret.NamesAndTypes = readPubNamesAndTypes(Dwarf, Config->IsLE);
return Ret;
}
+template <class ELFT> GdbIndexSection *elf::createGdbIndex() {
+ std::vector<GdbIndexChunk> Chunks;
+ for (InputSection *Sec : getDebugInfoSections()) {
+ InputFile *F = Sec->File;
+ std::error_code EC;
+ ELFObjectFile<ELFT> Obj(F->MB, EC);
+ if (EC)
+ fatal(EC.message());
+ DWARFContextInMemory Dwarf(Obj, nullptr, [&](Error E) {
+ error(toString(F) + ": error parsing DWARF data:\n>>> " +
+ toString(std::move(E)));
+ return ErrorPolicy::Continue;
+ });
+ Chunks.push_back(readDwarf(Dwarf, Sec));
+ }
+ return make<GdbIndexSection>(std::move(Chunks));
+}
+
static size_t getCuSize(std::vector<GdbIndexChunk> &C) {
size_t Ret = 0;
for (GdbIndexChunk &D : C)
@@ -1881,7 +1882,7 @@ void GdbIndexSection::writeTo(uint8_t *B
// Write the CU list.
for (GdbIndexChunk &D : Chunks) {
for (CompilationUnitEntry &Cu : D.CompilationUnits) {
- write64le(Buf, Cu.CuOffset);
+ write64le(Buf, D.DebugInfoSec->OutSecOff + Cu.CuOffset);
write64le(Buf + 8, Cu.CuLength);
Buf += 16;
}
@@ -2350,6 +2351,11 @@ StringTableSection *InX::ShStrTab;
StringTableSection *InX::StrTab;
SymbolTableBaseSection *InX::SymTab;
+template GdbIndexSection *elf::createGdbIndex<ELF32LE>();
+template GdbIndexSection *elf::createGdbIndex<ELF32BE>();
+template GdbIndexSection *elf::createGdbIndex<ELF64LE>();
+template GdbIndexSection *elf::createGdbIndex<ELF64BE>();
+
template void PltSection::addEntry<ELF32LE>(SymbolBody &Sym);
template void PltSection::addEntry<ELF32BE>(SymbolBody &Sym);
template void PltSection::addEntry<ELF64LE>(SymbolBody &Sym);
Modified: lld/trunk/ELF/SyntheticSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.h?rev=307867&r1=307866&r2=307867&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.h (original)
+++ lld/trunk/ELF/SyntheticSections.h Wed Jul 12 16:56:53 2017
@@ -503,7 +503,7 @@ class GdbIndexSection final : public Syn
const unsigned SymTabEntrySize = 2 * OffsetTypeSize;
public:
- GdbIndexSection();
+ GdbIndexSection(std::vector<GdbIndexChunk> &&Chunks);
void finalizeContents() override;
void writeTo(uint8_t *Buf) override;
size_t getSize() const override;
@@ -524,7 +524,6 @@ public:
std::vector<GdbIndexChunk> Chunks;
private:
- GdbIndexChunk readDwarf(InputSection *Sec);
void buildIndex();
uint32_t CuTypesOffset;
@@ -538,6 +537,8 @@ private:
bool Finalized = false;
};
+template <class ELFT> GdbIndexSection *createGdbIndex();
+
// --eh-frame-hdr option tells linker to construct a header for all the
// .eh_frame sections. This header is placed to a section named .eh_frame_hdr
// and also to a PT_GNU_EH_FRAME segment.
Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=307867&r1=307866&r2=307867&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Wed Jul 12 16:56:53 2017
@@ -380,7 +380,7 @@ template <class ELFT> void Writer<ELFT>:
Add(InX::IgotPlt);
if (Config->GdbIndex) {
- InX::GdbIndex = make<GdbIndexSection>();
+ InX::GdbIndex = createGdbIndex<ELFT>();
Add(InX::GdbIndex);
}
More information about the llvm-commits
mailing list