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-rw-r--r--llvm/lib/MC/ELFObjectWriter.cpp86
-rw-r--r--llvm/lib/MC/MCSymbol.cpp17
2 files changed, 66 insertions, 37 deletions
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 909ea80..0f3fa04 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -271,6 +271,7 @@ class ELFObjectWriter : public MCObjectWriter {
/// \param RevGroupMap - Maps a signature symbol to the group section.
/// \param NumRegularSections - Number of non-relocation sections.
void ComputeSymbolTable(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
const SectionIndexMapTy &SectionIndexMap,
RevGroupMapTy RevGroupMap,
unsigned NumRegularSections);
@@ -462,33 +463,43 @@ void ELFObjectWriter::WriteSymbolEntry(MCDataFragment *SymtabF,
}
}
-uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &Data,
+uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &OrigData,
const MCAsmLayout &Layout) {
- if (Data.isCommon() && Data.isExternal())
- return Data.getCommonAlignment();
-
- const MCSymbol &Symbol = Data.getSymbol();
-
- if (Symbol.isAbsolute() && Symbol.isVariable()) {
- if (const MCExpr *Value = Symbol.getVariableValue()) {
- int64_t IntValue;
- if (Value->EvaluateAsAbsolute(IntValue, Layout))
- return (uint64_t)IntValue;
- }
+ MCSymbolData *Data = &OrigData;
+ if (Data->isCommon() && Data->isExternal())
+ return Data->getCommonAlignment();
+
+ const MCSymbol *Symbol = &Data->getSymbol();
+
+ uint64_t Res = 0;
+ if (Symbol->isVariable()) {
+ const MCExpr *Expr = Symbol->getVariableValue();
+ MCValue Value;
+ if (!Expr->EvaluateAsRelocatable(Value, &Layout))
+ return 0;
+ if (Value.getSymB())
+ return 0;
+ Res = Value.getConstant();
+
+ const MCSymbolRefExpr *A = Value.getSymA();
+ if (!A)
+ return Res;
+
+ Symbol = &A->getSymbol();
+ Data = &Layout.getAssembler().getSymbolData(*Symbol);
}
- if (!Symbol.isInSection())
+ if (!Symbol->isInSection())
return 0;
+ if (!Data->getFragment())
+ return 0;
- if (Data.getFragment()) {
- if (Data.getFlags() & ELF_Other_ThumbFunc)
- return Layout.getSymbolOffset(&Data)+1;
- else
- return Layout.getSymbolOffset(&Data);
- }
+ Res += Layout.getSymbolOffset(Data);
+ if (Data->getFlags() & ELF_Other_ThumbFunc)
+ ++Res;
- return 0;
+ return Res;
}
void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
@@ -586,7 +597,7 @@ void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
uint8_t Other = MCELF::getOther(OrigData) << (ELF_STO_Shift - ELF_STV_Shift);
Other |= Visibility;
- uint64_t Value = SymbolValue(Data, Layout);
+ uint64_t Value = SymbolValue(OrigData, Layout);
uint64_t Size = 0;
assert(!(Data.isCommon() && !Data.isExternal()));
@@ -897,10 +908,11 @@ void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm,
}
}
-void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm,
- const SectionIndexMapTy &SectionIndexMap,
- RevGroupMapTy RevGroupMap,
- unsigned NumRegularSections) {
+void
+ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout,
+ const SectionIndexMapTy &SectionIndexMap,
+ RevGroupMapTy RevGroupMap,
+ unsigned NumRegularSections) {
// FIXME: Is this the correct place to do this?
// FIXME: Why is an undefined reference to _GLOBAL_OFFSET_TABLE_ needed?
if (NeedsGOT) {
@@ -948,33 +960,33 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm,
ELFSymbolData MSD;
MSD.SymbolData = it;
- const MCSymbol &RefSymbol = Symbol.AliasedSymbol();
+ const MCSymbol *BaseSymbol = Symbol.getBaseSymbol(Layout);
// Undefined symbols are global, but this is the first place we
// are able to set it.
bool Local = isLocal(*it, isSignature, Used);
if (!Local && MCELF::GetBinding(*it) == ELF::STB_LOCAL) {
- MCSymbolData &SD = Asm.getSymbolData(RefSymbol);
+ assert(BaseSymbol);
+ MCSymbolData &SD = Asm.getSymbolData(*BaseSymbol);
MCELF::SetBinding(*it, ELF::STB_GLOBAL);
MCELF::SetBinding(SD, ELF::STB_GLOBAL);
}
- if (RefSymbol.isUndefined() && !Used && WeakrefUsed)
- MCELF::SetBinding(*it, ELF::STB_WEAK);
-
- if (it->isCommon()) {
+ if (!BaseSymbol) {
+ MSD.SectionIndex = ELF::SHN_ABS;
+ } else if (it->isCommon()) {
assert(!Local);
MSD.SectionIndex = ELF::SHN_COMMON;
- } else if (Symbol.isAbsolute() || RefSymbol.isVariable()) {
- MSD.SectionIndex = ELF::SHN_ABS;
- } else if (RefSymbol.isUndefined()) {
+ } else if (BaseSymbol->isUndefined()) {
if (isSignature && !Used)
MSD.SectionIndex = SectionIndexMap.lookup(RevGroupMap[&Symbol]);
else
MSD.SectionIndex = ELF::SHN_UNDEF;
+ if (!Used && WeakrefUsed)
+ MCELF::SetBinding(*it, ELF::STB_WEAK);
} else {
const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(RefSymbol.getSection());
+ static_cast<const MCSectionELF&>(BaseSymbol->getSection());
MSD.SectionIndex = SectionIndexMap.lookup(&Section);
if (MSD.SectionIndex >= ELF::SHN_LORESERVE)
NeedsSymtabShndx = true;
@@ -1560,8 +1572,8 @@ void ELFObjectWriter::WriteObject(MCAssembler &Asm,
unsigned NumRegularSections = NumUserSections + NumIndexedSections;
// Compute symbol table information.
- ComputeSymbolTable(Asm, SectionIndexMap, RevGroupMap, NumRegularSections);
-
+ ComputeSymbolTable(Asm, Layout, SectionIndexMap, RevGroupMap,
+ NumRegularSections);
WriteRelocations(Asm, const_cast<MCAsmLayout&>(Layout), RelMap);
diff --git a/llvm/lib/MC/MCSymbol.cpp b/llvm/lib/MC/MCSymbol.cpp
index 2416525..d0283a6 100644
--- a/llvm/lib/MC/MCSymbol.cpp
+++ b/llvm/lib/MC/MCSymbol.cpp
@@ -9,6 +9,7 @@
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
@@ -51,6 +52,22 @@ const MCSymbol &MCSymbol::AliasedSymbol() const {
return *S;
}
+const MCSymbol *MCSymbol::getBaseSymbol(const MCAsmLayout &Layout) const {
+ if (!isVariable())
+ return this;
+
+ const MCExpr *Expr = getVariableValue();
+ MCValue Value;
+ if (!Expr->EvaluateAsRelocatable(Value, &Layout))
+ return nullptr;
+
+ if (Value.getSymB())
+ return nullptr;
+ if (const MCSymbolRefExpr *A = Value.getSymA())
+ return &A->getSymbol();
+ return nullptr;
+}
+
void MCSymbol::setVariableValue(const MCExpr *Value) {
assert(!IsUsed && "Cannot set a variable that has already been used.");
assert(Value && "Invalid variable value!");
generated by cgit v1.1 at 2025-10-17 11:53:38 +0000