Compute A-B when A or B is weak.
Similar to r235222, but for the weak symbol case.
In an "ideal" assembler/object format an expression would always refer to the
final value and A-B would only be computed from a section in the same
comdat as A and B with A and B strong.
Unfortunately that is not the case with debug info on ELF, so we need an
heuristic. Since we need an heuristic, we may as well use the same one as
gas:
* call weak_sym : produces a relocation, even if in the same section.
* A - weak_sym and weak_sym -A: don't produce a relocation if we can
compute it.
This fixes pr23272 and changes the fix of pr22815 to match what gas does.
llvm-svn: 235227
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 32ec969..1646fe5 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -275,7 +275,6 @@
bool
IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
const MCSymbolData &DataA,
- const MCSymbolData *DataB,
const MCFragment &FB,
bool InSet,
bool IsPCRel) const override;
@@ -1669,13 +1668,15 @@
}
bool ELFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
- const MCAssembler &Asm, const MCSymbolData &DataA,
- const MCSymbolData *DataB, const MCFragment &FB, bool InSet,
- bool IsPCRel) const {
- if (!InSet && (::isWeak(DataA) || (DataB && ::isWeak(*DataB))))
- return false;
- return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
- Asm, DataA, DataB, FB, InSet, IsPCRel);
+ const MCAssembler &Asm, const MCSymbolData &DataA, const MCFragment &FB,
+ bool InSet, bool IsPCRel) const {
+ if (IsPCRel) {
+ assert(!InSet);
+ if (::isWeak(DataA))
+ return false;
+ }
+ return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA, FB,
+ InSet, IsPCRel);
}
bool ELFObjectWriter::isWeak(const MCSymbolData &SD) const {
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index d09e383..a7df95a 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -504,7 +504,7 @@
} else {
const MCSymbolData &DataA = getSymbolData(SA);
IsResolved = getWriter().IsSymbolRefDifferenceFullyResolvedImpl(
- *this, DataA, nullptr, *DF, false, true);
+ *this, DataA, *DF, false, true);
}
}
} else {
diff --git a/llvm/lib/MC/MCObjectWriter.cpp b/llvm/lib/MC/MCObjectWriter.cpp
index e40c07d..e90dea8 100644
--- a/llvm/lib/MC/MCObjectWriter.cpp
+++ b/llvm/lib/MC/MCObjectWriter.cpp
@@ -36,13 +36,12 @@
return false;
return IsSymbolRefDifferenceFullyResolvedImpl(
- Asm, DataA, &DataB, *DataB.getFragment(), InSet, false);
+ Asm, DataA, *DataB.getFragment(), InSet, false);
}
bool MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
- const MCAssembler &Asm, const MCSymbolData &DataA,
- const MCSymbolData *DataB, const MCFragment &FB, bool InSet,
- bool IsPCRel) const {
+ const MCAssembler &Asm, const MCSymbolData &DataA, const MCFragment &FB,
+ bool InSet, bool IsPCRel) const {
const MCSection &SecA = DataA.getSymbol().getSection();
const MCSection &SecB = FB.getParent()->getSection();
// On ELF and COFF A - B is absolute if A and B are in the same section.
diff --git a/llvm/lib/MC/MachObjectWriter.cpp b/llvm/lib/MC/MachObjectWriter.cpp
index 97143a9..dc68a89 100644
--- a/llvm/lib/MC/MachObjectWriter.cpp
+++ b/llvm/lib/MC/MachObjectWriter.cpp
@@ -669,13 +669,9 @@
BindIndirectSymbols(Asm);
}
-bool MachObjectWriter::
-IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
- const MCSymbolData &DataA,
- const MCSymbolData *DataB,
- const MCFragment &FB,
- bool InSet,
- bool IsPCRel) const {
+bool MachObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
+ const MCAssembler &Asm, const MCSymbolData &DataA, const MCFragment &FB,
+ bool InSet, bool IsPCRel) const {
if (InSet)
return true;
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index a4b6bf9..5854630 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -172,7 +172,6 @@
bool IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
const MCSymbolData &DataA,
- const MCSymbolData *DataB,
const MCFragment &FB, bool InSet,
bool IsPCRel) const override;
@@ -649,17 +648,16 @@
}
bool WinCOFFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
- const MCAssembler &Asm, const MCSymbolData &DataA,
- const MCSymbolData *DataB, const MCFragment &FB, bool InSet,
- bool IsPCRel) const {
+ const MCAssembler &Asm, const MCSymbolData &DataA, const MCFragment &FB,
+ bool InSet, bool IsPCRel) const {
// MS LINK expects to be able to replace all references to a function with a
// thunk to implement their /INCREMENTAL feature. Make sure we don't optimize
// away any relocations to functions.
if ((((DataA.getFlags() & COFF::SF_TypeMask) >> COFF::SF_TypeShift) >>
COFF::SCT_COMPLEX_TYPE_SHIFT) == COFF::IMAGE_SYM_DTYPE_FUNCTION)
return false;
- return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
- Asm, DataA, DataB, FB, InSet, IsPCRel);
+ return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA, FB,
+ InSet, IsPCRel);
}
bool WinCOFFObjectWriter::isWeak(const MCSymbolData &SD) const {