[llvm-commits] [llvm] r120683 - in /llvm/trunk: include/llvm/MC/MCAssembler.h lib/MC/ELFObjectWriter.cpp lib/MC/MCAssembler.cpp
Rafael Espindola
rafael.espindola at gmail.com
Wed Dec 1 19:09:06 PST 2010
Author: rafael
Date: Wed Dec 1 21:09:06 2010
New Revision: 120683
URL: http://llvm.org/viewvc/llvm-project?rev=120683&view=rev
Log:
The sections that the ELF object writer has to create are very simple and
contain only data. Handle them specially instead of using AddSectionToTheEnd.
This moves a hack from the generic assembler to the elf writer. It is also
a bit faster and should make other improvements easier.
Modified:
llvm/trunk/include/llvm/MC/MCAssembler.h
llvm/trunk/lib/MC/ELFObjectWriter.cpp
llvm/trunk/lib/MC/MCAssembler.cpp
Modified: llvm/trunk/include/llvm/MC/MCAssembler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAssembler.h?rev=120683&r1=120682&r2=120683&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAssembler.h (original)
+++ llvm/trunk/include/llvm/MC/MCAssembler.h Wed Dec 1 21:09:06 2010
@@ -481,6 +481,8 @@
unsigned getLayoutOrder() const { return LayoutOrder; }
void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }
+ uint64_t getAddress() const { return Address; }
+
/// @name Fragment Access
/// @{
@@ -757,9 +759,6 @@
void WriteSectionData(const MCSectionData *Section, const MCAsmLayout &Layout,
MCObjectWriter *OW) const;
- void AddSectionToTheEnd(const MCObjectWriter &Writer, MCSectionData &SD,
- MCAsmLayout &Layout);
-
public:
/// Construct a new assembler instance.
///
Modified: llvm/trunk/lib/MC/ELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/ELFObjectWriter.cpp?rev=120683&r1=120682&r2=120683&view=diff
==============================================================================
--- llvm/trunk/lib/MC/ELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/ELFObjectWriter.cpp Wed Dec 1 21:09:06 2010
@@ -982,8 +982,6 @@
MCDataFragment *F = new MCDataFragment(&RelaSD);
WriteRelocationsFragment(Asm, F, &SD);
-
- Asm.AddSectionToTheEnd(*this, RelaSD, Layout);
}
}
@@ -1091,14 +1089,11 @@
MCDataFragment *ShndxF = NULL;
if (NeedsSymtabShndx) {
ShndxF = new MCDataFragment(SymtabShndxSD);
- Asm.AddSectionToTheEnd(*this, *SymtabShndxSD, Layout);
}
WriteSymbolTable(F, ShndxF, Asm, Layout, SectionIndexMap);
- Asm.AddSectionToTheEnd(*this, SymtabSD, Layout);
F = new MCDataFragment(&StrtabSD);
F->getContents().append(StringTable.begin(), StringTable.end());
- Asm.AddSectionToTheEnd(*this, StrtabSD, Layout);
F = new MCDataFragment(&ShstrtabSD);
@@ -1130,8 +1125,6 @@
F->getContents() += Name;
F->getContents() += '\x00';
}
-
- Asm.AddSectionToTheEnd(*this, ShstrtabSD, Layout);
}
bool ELFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm,
@@ -1220,13 +1213,6 @@
MCDataFragment *F = new MCDataFragment(&Data);
String32(*F, NumGroups + Index);
}
-
- for (RevGroupMapTy::const_iterator i = RevGroupMap.begin(),
- e = RevGroupMap.end(); i != e; ++i) {
- const MCSectionELF *Group = i->second;
- MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
- Asm.AddSectionToTheEnd(*this, Data, Layout);
- }
}
void ELFObjectWriter::WriteSection(MCAssembler &Asm,
@@ -1299,6 +1285,45 @@
Alignment, Section.getEntrySize());
}
+static bool IsELFMetaDataSection(const MCSectionData &SD) {
+ return SD.getAddress() == ~UINT64_C(0) &&
+ !SD.getSection().isVirtualSection();
+}
+
+static uint64_t DataSectionSize(const MCSectionData &SD) {
+ uint64_t Ret = 0;
+ for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e;
+ ++i) {
+ const MCFragment &F = *i;
+ assert(F.getKind() == MCFragment::FT_Data);
+ Ret += cast<MCDataFragment>(F).getContents().size();
+ }
+ return Ret;
+}
+
+static uint64_t GetSectionFileSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
+ if (IsELFMetaDataSection(SD))
+ return DataSectionSize(SD);
+ return Layout.getSectionFileSize(&SD);
+}
+
+static uint64_t GetSectionSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
+ if (IsELFMetaDataSection(SD))
+ return DataSectionSize(SD);
+ return Layout.getSectionSize(&SD);
+}
+
+static void WriteDataSectionData(ELFObjectWriter *W, const MCSectionData &SD) {
+ for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e;
+ ++i) {
+ const MCFragment &F = *i;
+ assert(F.getKind() == MCFragment::FT_Data);
+ W->WriteBytes(cast<MCDataFragment>(F).getContents().str());
+ }
+}
+
void ELFObjectWriter::WriteObject(MCAssembler &Asm,
const MCAsmLayout &Layout) {
GroupMapTy GroupMap;
@@ -1342,9 +1367,7 @@
FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
// Get the size of the section in the output file (including padding).
- uint64_t Size = Layout.getSectionFileSize(&SD);
-
- FileOff += Size;
+ FileOff += GetSectionFileSize(Layout, SD);
}
FileOff = RoundUpToAlignment(FileOff, NaturalAlignment);
@@ -1368,9 +1391,12 @@
// Remember the offset into the file for this section.
SectionOffsetMap[&Section] = FileOff;
- FileOff += Layout.getSectionFileSize(&SD);
+ FileOff += GetSectionFileSize(Layout, SD);
- Asm.WriteSectionData(&SD, Layout, this);
+ if (IsELFMetaDataSection(SD))
+ WriteDataSectionData(this, SD);
+ else
+ Asm.WriteSectionData(&SD, Layout, this);
}
uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
@@ -1396,8 +1422,10 @@
else
GroupSymbolIndex = getSymbolIndexInSymbolTable(Asm, GroupMap[&Section]);
+ uint64_t Size = GetSectionSize(Layout, SD);
+
WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
- SectionOffsetMap[&Section], Layout.getSectionSize(&SD),
+ SectionOffsetMap[&Section], Size,
SD.getAlignment(), Section);
}
}
Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=120683&r1=120682&r2=120683&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Wed Dec 1 21:09:06 2010
@@ -618,26 +618,6 @@
assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD));
}
-void MCAssembler::AddSectionToTheEnd(const MCObjectWriter &Writer,
- MCSectionData &SD, MCAsmLayout &Layout) {
- // Create dummy fragments and assign section ordinals.
- unsigned SectionIndex = size();
- SD.setOrdinal(SectionIndex);
-
- // Assign layout order indices to sections and fragments.
- const MCFragment &Last = *Layout.getSectionOrder().back()->rbegin();
- unsigned FragmentIndex = Last.getLayoutOrder() + 1;
-
- SD.setLayoutOrder(Layout.getSectionOrder().size());
- for (MCSectionData::iterator it2 = SD.begin(),
- ie2 = SD.end(); it2 != ie2; ++it2) {
- it2->setLayoutOrder(FragmentIndex++);
- }
- Layout.getSectionOrder().push_back(&SD);
-
- Layout.LayoutSection(&SD);
-}
-
void MCAssembler::Finish(MCObjectWriter *Writer) {
DEBUG_WITH_TYPE("mc-dump", {
llvm::errs() << "assembler backend - pre-layout\n--\n";
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