[llvm] 0502270 - [NFC][COFF] Refine access specifiers for WinCOFFObjectWriter
Haohai Wen via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 6 06:01:53 PDT 2023
Author: Haohai Wen
Date: 2023-06-06T21:01:45+08:00
New Revision: 050227004ca34cd5cb8e65f214c49b47c206c4b3
URL: https://github.com/llvm/llvm-project/commit/050227004ca34cd5cb8e65f214c49b47c206c4b3
DIFF: https://github.com/llvm/llvm-project/commit/050227004ca34cd5cb8e65f214c49b47c206c4b3.diff
LOG: [NFC][COFF] Refine access specifiers for WinCOFFObjectWriter
Set public specifiers only for constructor and inherited methods from
MCObjectWriter and leave others as private. Also change the order of
MCObjectWriter methods' definition according to it's declaration order.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D152229
Added:
Modified:
llvm/lib/MC/WinCOFFObjectWriter.cpp
Removed:
################################################################################
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index 65adce2a633b5..7b56276744394 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -122,7 +122,6 @@ class COFFSection {
};
class WinCOFFObjectWriter : public MCObjectWriter {
-public:
support::endian::Writer W;
using symbols = std::vector<std::unique_ptr<COFFSymbol>>;
@@ -154,9 +153,11 @@ class WinCOFFObjectWriter : public MCObjectWriter {
MCSectionCOFF *CGProfileSection = nullptr;
+public:
WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
raw_pwrite_stream &OS);
+ // MCObjectWriter interface implementation.
void reset() override {
memset(&Header, 0, sizeof(Header));
Header.Machine = TargetObjectWriter->getMachine();
@@ -169,6 +170,18 @@ class WinCOFFObjectWriter : public MCObjectWriter {
MCObjectWriter::reset();
}
+ void executePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) override;
+ bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbol &SymA,
+ const MCFragment &FB, bool InSet,
+ bool IsPCRel) const override;
+ void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCFragment *Fragment, const MCFixup &Fixup,
+ MCValue Target, uint64_t &FixedValue) override;
+ uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
+
+private:
COFFSymbol *createSymbol(StringRef Name);
COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol *Symbol);
COFFSection *createSection(StringRef Name);
@@ -196,26 +209,10 @@ class WinCOFFObjectWriter : public MCObjectWriter {
void writeSection(MCAssembler &Asm, const MCAsmLayout &Layout,
const COFFSection &Sec);
- // MCObjectWriter interface implementation.
-
- void executePostLayoutBinding(MCAssembler &Asm,
- const MCAsmLayout &Layout) override;
-
- bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
- const MCSymbol &SymA,
- const MCFragment &FB, bool InSet,
- bool IsPCRel) const override;
-
- void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, uint64_t &FixedValue) override;
-
void createFileSymbols(MCAssembler &Asm);
void setWeakDefaultNames();
void assignSectionNumbers();
void assignFileOffsets(MCAssembler &Asm, const MCAsmLayout &Layout);
-
- uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
};
} // end anonymous namespace
@@ -642,6 +639,165 @@ void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
WriteRelocation(Relocation.Data);
}
+// Create .file symbols.
+void WinCOFFObjectWriter::createFileSymbols(MCAssembler &Asm) {
+ for (const std::pair<std::string, size_t> &It : Asm.getFileNames()) {
+ // round up to calculate the number of auxiliary symbols required
+ const std::string &Name = It.first;
+ unsigned SymbolSize = UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size;
+ unsigned Count = (Name.size() + SymbolSize - 1) / SymbolSize;
+
+ COFFSymbol *File = createSymbol(".file");
+ File->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
+ File->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
+ File->Aux.resize(Count);
+
+ unsigned Offset = 0;
+ unsigned Length = Name.size();
+ for (auto &Aux : File->Aux) {
+ Aux.AuxType = ATFile;
+
+ if (Length > SymbolSize) {
+ memcpy(&Aux.Aux, Name.c_str() + Offset, SymbolSize);
+ Length = Length - SymbolSize;
+ } else {
+ memcpy(&Aux.Aux, Name.c_str() + Offset, Length);
+ memset((char *)&Aux.Aux + Length, 0, SymbolSize - Length);
+ break;
+ }
+
+ Offset += SymbolSize;
+ }
+ }
+}
+
+void WinCOFFObjectWriter::setWeakDefaultNames() {
+ if (WeakDefaults.empty())
+ return;
+
+ // If multiple object files use a weak symbol (either with a regular
+ // defined default, or an absolute zero symbol as default), the defaults
+ // cause duplicate definitions unless their names are made unique. Look
+ // for a defined extern symbol, that isn't comdat - that should be unique
+ // unless there are other duplicate definitions. And if none is found,
+ // allow picking a comdat symbol, as that's still better than nothing.
+
+ COFFSymbol *Unique = nullptr;
+ for (bool AllowComdat : {false, true}) {
+ for (auto &Sym : Symbols) {
+ // Don't include the names of the defaults themselves
+ if (WeakDefaults.count(Sym.get()))
+ continue;
+ // Only consider external symbols
+ if (Sym->Data.StorageClass != COFF::IMAGE_SYM_CLASS_EXTERNAL)
+ continue;
+ // Only consider symbols defined in a section or that are absolute
+ if (!Sym->Section && Sym->Data.SectionNumber != COFF::IMAGE_SYM_ABSOLUTE)
+ continue;
+ if (!AllowComdat && Sym->Section &&
+ Sym->Section->Header.Characteristics & COFF::IMAGE_SCN_LNK_COMDAT)
+ continue;
+ Unique = Sym.get();
+ break;
+ }
+ if (Unique)
+ break;
+ }
+ // If we didn't find any unique symbol to use for the names, just skip this.
+ if (!Unique)
+ return;
+ for (auto *Sym : WeakDefaults) {
+ Sym->Name.append(".");
+ Sym->Name.append(Unique->Name);
+ }
+}
+
+static bool isAssociative(const COFFSection &Section) {
+ return Section.Symbol->Aux[0].Aux.SectionDefinition.Selection ==
+ COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
+}
+
+void WinCOFFObjectWriter::assignSectionNumbers() {
+ size_t I = 1;
+ auto Assign = [&](COFFSection &Section) {
+ Section.Number = I;
+ Section.Symbol->Data.SectionNumber = I;
+ Section.Symbol->Aux[0].Aux.SectionDefinition.Number = I;
+ ++I;
+ };
+
+ // Although it is not explicitly requested by the Microsoft COFF spec,
+ // we should avoid emitting forward associative section references,
+ // because MSVC link.exe as of 2017 cannot handle that.
+ for (const std::unique_ptr<COFFSection> &Section : Sections)
+ if (!isAssociative(*Section))
+ Assign(*Section);
+ for (const std::unique_ptr<COFFSection> &Section : Sections)
+ if (isAssociative(*Section))
+ Assign(*Section);
+}
+
+// Assign file offsets to COFF object file structures.
+void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ unsigned Offset = W.OS.tell();
+
+ Offset += UseBigObj ? COFF::Header32Size : COFF::Header16Size;
+ Offset += COFF::SectionSize * Header.NumberOfSections;
+
+ for (const auto &Section : Asm) {
+ COFFSection *Sec = SectionMap[&Section];
+
+ if (!Sec || Sec->Number == -1)
+ continue;
+
+ Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
+
+ if (IsPhysicalSection(Sec)) {
+ Sec->Header.PointerToRawData = Offset;
+ Offset += Sec->Header.SizeOfRawData;
+ }
+
+ if (!Sec->Relocations.empty()) {
+ bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
+
+ if (RelocationsOverflow) {
+ // Signal overflow by setting NumberOfRelocations to max value. Actual
+ // size is found in reloc #0. Microsoft tools understand this.
+ Sec->Header.NumberOfRelocations = 0xffff;
+ } else {
+ Sec->Header.NumberOfRelocations = Sec->Relocations.size();
+ }
+ Sec->Header.PointerToRelocations = Offset;
+
+ if (RelocationsOverflow) {
+ // Reloc #0 will contain actual count, so make room for it.
+ Offset += COFF::RelocationSize;
+ }
+
+ Offset += COFF::RelocationSize * Sec->Relocations.size();
+
+ for (auto &Relocation : Sec->Relocations) {
+ assert(Relocation.Symb->getIndex() != -1);
+ Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
+ }
+ }
+
+ assert(Sec->Symbol->Aux.size() == 1 &&
+ "Section's symbol must have one aux!");
+ AuxSymbol &Aux = Sec->Symbol->Aux[0];
+ assert(Aux.AuxType == ATSectionDefinition &&
+ "Section's symbol's aux symbol must be a Section Definition!");
+ Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
+ Aux.Aux.SectionDefinition.NumberOfRelocations =
+ Sec->Header.NumberOfRelocations;
+ Aux.Aux.SectionDefinition.NumberOfLinenumbers =
+ Sec->Header.NumberOfLineNumbers;
+ }
+
+ Header.PointerToSymbolTable = Offset;
+}
+
////////////////////////////////////////////////////////////////////////////////
// MCObjectWriter interface implementations
@@ -845,165 +1001,6 @@ static std::time_t getTime() {
return Now;
}
-// Create .file symbols.
-void WinCOFFObjectWriter::createFileSymbols(MCAssembler &Asm) {
- for (const std::pair<std::string, size_t> &It : Asm.getFileNames()) {
- // round up to calculate the number of auxiliary symbols required
- const std::string &Name = It.first;
- unsigned SymbolSize = UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size;
- unsigned Count = (Name.size() + SymbolSize - 1) / SymbolSize;
-
- COFFSymbol *File = createSymbol(".file");
- File->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
- File->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
- File->Aux.resize(Count);
-
- unsigned Offset = 0;
- unsigned Length = Name.size();
- for (auto &Aux : File->Aux) {
- Aux.AuxType = ATFile;
-
- if (Length > SymbolSize) {
- memcpy(&Aux.Aux, Name.c_str() + Offset, SymbolSize);
- Length = Length - SymbolSize;
- } else {
- memcpy(&Aux.Aux, Name.c_str() + Offset, Length);
- memset((char *)&Aux.Aux + Length, 0, SymbolSize - Length);
- break;
- }
-
- Offset += SymbolSize;
- }
- }
-}
-
-void WinCOFFObjectWriter::setWeakDefaultNames() {
- if (WeakDefaults.empty())
- return;
-
- // If multiple object files use a weak symbol (either with a regular
- // defined default, or an absolute zero symbol as default), the defaults
- // cause duplicate definitions unless their names are made unique. Look
- // for a defined extern symbol, that isn't comdat - that should be unique
- // unless there are other duplicate definitions. And if none is found,
- // allow picking a comdat symbol, as that's still better than nothing.
-
- COFFSymbol *Unique = nullptr;
- for (bool AllowComdat : {false, true}) {
- for (auto &Sym : Symbols) {
- // Don't include the names of the defaults themselves
- if (WeakDefaults.count(Sym.get()))
- continue;
- // Only consider external symbols
- if (Sym->Data.StorageClass != COFF::IMAGE_SYM_CLASS_EXTERNAL)
- continue;
- // Only consider symbols defined in a section or that are absolute
- if (!Sym->Section && Sym->Data.SectionNumber != COFF::IMAGE_SYM_ABSOLUTE)
- continue;
- if (!AllowComdat && Sym->Section &&
- Sym->Section->Header.Characteristics & COFF::IMAGE_SCN_LNK_COMDAT)
- continue;
- Unique = Sym.get();
- break;
- }
- if (Unique)
- break;
- }
- // If we didn't find any unique symbol to use for the names, just skip this.
- if (!Unique)
- return;
- for (auto *Sym : WeakDefaults) {
- Sym->Name.append(".");
- Sym->Name.append(Unique->Name);
- }
-}
-
-static bool isAssociative(const COFFSection &Section) {
- return Section.Symbol->Aux[0].Aux.SectionDefinition.Selection ==
- COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
-}
-
-void WinCOFFObjectWriter::assignSectionNumbers() {
- size_t I = 1;
- auto Assign = [&](COFFSection &Section) {
- Section.Number = I;
- Section.Symbol->Data.SectionNumber = I;
- Section.Symbol->Aux[0].Aux.SectionDefinition.Number = I;
- ++I;
- };
-
- // Although it is not explicitly requested by the Microsoft COFF spec,
- // we should avoid emitting forward associative section references,
- // because MSVC link.exe as of 2017 cannot handle that.
- for (const std::unique_ptr<COFFSection> &Section : Sections)
- if (!isAssociative(*Section))
- Assign(*Section);
- for (const std::unique_ptr<COFFSection> &Section : Sections)
- if (isAssociative(*Section))
- Assign(*Section);
-}
-
-// Assign file offsets to COFF object file structures.
-void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
- const MCAsmLayout &Layout) {
- unsigned Offset = W.OS.tell();
-
- Offset += UseBigObj ? COFF::Header32Size : COFF::Header16Size;
- Offset += COFF::SectionSize * Header.NumberOfSections;
-
- for (const auto &Section : Asm) {
- COFFSection *Sec = SectionMap[&Section];
-
- if (!Sec || Sec->Number == -1)
- continue;
-
- Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
-
- if (IsPhysicalSection(Sec)) {
- Sec->Header.PointerToRawData = Offset;
- Offset += Sec->Header.SizeOfRawData;
- }
-
- if (!Sec->Relocations.empty()) {
- bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
-
- if (RelocationsOverflow) {
- // Signal overflow by setting NumberOfRelocations to max value. Actual
- // size is found in reloc #0. Microsoft tools understand this.
- Sec->Header.NumberOfRelocations = 0xffff;
- } else {
- Sec->Header.NumberOfRelocations = Sec->Relocations.size();
- }
- Sec->Header.PointerToRelocations = Offset;
-
- if (RelocationsOverflow) {
- // Reloc #0 will contain actual count, so make room for it.
- Offset += COFF::RelocationSize;
- }
-
- Offset += COFF::RelocationSize * Sec->Relocations.size();
-
- for (auto &Relocation : Sec->Relocations) {
- assert(Relocation.Symb->getIndex() != -1);
- Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
- }
- }
-
- assert(Sec->Symbol->Aux.size() == 1 &&
- "Section's symbol must have one aux!");
- AuxSymbol &Aux = Sec->Symbol->Aux[0];
- assert(Aux.AuxType == ATSectionDefinition &&
- "Section's symbol's aux symbol must be a Section Definition!");
- Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
- Aux.Aux.SectionDefinition.NumberOfRelocations =
- Sec->Header.NumberOfRelocations;
- Aux.Aux.SectionDefinition.NumberOfLinenumbers =
- Sec->Header.NumberOfLineNumbers;
- }
-
- Header.PointerToSymbolTable = Offset;
-}
-
uint64_t WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
const MCAsmLayout &Layout) {
uint64_t StartOffset = W.OS.tell();
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