#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCObjectFormat.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
// absolute names.
bool UseParens = Sym.getName()[0] == '$';
- if (SRE.getKind() == MCSymbolRefExpr::VK_ARM_HI16 ||
- SRE.getKind() == MCSymbolRefExpr::VK_ARM_LO16)
- OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
-
if (SRE.getKind() == MCSymbolRefExpr::VK_PPC_HA16 ||
SRE.getKind() == MCSymbolRefExpr::VK_PPC_LO16) {
OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
SRE.getKind() == MCSymbolRefExpr::VK_ARM_GOTTPOFF)
OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
else if (SRE.getKind() != MCSymbolRefExpr::VK_None &&
- SRE.getKind() != MCSymbolRefExpr::VK_ARM_HI16 &&
- SRE.getKind() != MCSymbolRefExpr::VK_ARM_LO16 &&
SRE.getKind() != MCSymbolRefExpr::VK_PPC_HA16 &&
SRE.getKind() != MCSymbolRefExpr::VK_PPC_LO16)
OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
case VK_TPOFF: return "TPOFF";
case VK_DTPOFF: return "DTPOFF";
case VK_TLVP: return "TLVP";
- case VK_ARM_HI16: return ":upper16:";
- case VK_ARM_LO16: return ":lower16:";
case VK_ARM_PLT: return "(PLT)";
case VK_ARM_GOT: return "(GOT)";
case VK_ARM_GOTOFF: return "(GOTOFF)";
MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
return StringSwitch<VariantKind>(Name)
.Case("GOT", VK_GOT)
+ .Case("got", VK_GOT)
.Case("GOTOFF", VK_GOTOFF)
+ .Case("gotoff", VK_GOTOFF)
.Case("GOTPCREL", VK_GOTPCREL)
+ .Case("gotpcrel", VK_GOTPCREL)
.Case("GOTTPOFF", VK_GOTTPOFF)
+ .Case("gottpoff", VK_GOTTPOFF)
.Case("INDNTPOFF", VK_INDNTPOFF)
+ .Case("indntpoff", VK_INDNTPOFF)
.Case("NTPOFF", VK_NTPOFF)
+ .Case("ntpoff", VK_NTPOFF)
.Case("GOTNTPOFF", VK_GOTNTPOFF)
+ .Case("gotntpoff", VK_GOTNTPOFF)
.Case("PLT", VK_PLT)
+ .Case("plt", VK_PLT)
.Case("TLSGD", VK_TLSGD)
+ .Case("tlsgd", VK_TLSGD)
.Case("TLSLD", VK_TLSLD)
+ .Case("tlsld", VK_TLSLD)
.Case("TLSLDM", VK_TLSLDM)
+ .Case("tlsldm", VK_TLSLDM)
.Case("TPOFF", VK_TPOFF)
+ .Case("tpoff", VK_TPOFF)
.Case("DTPOFF", VK_DTPOFF)
+ .Case("dtpoff", VK_DTPOFF)
.Case("TLVP", VK_TLVP)
+ .Case("tlvp", VK_TLVP)
.Default(VK_Invalid);
}
/* *** */
bool MCExpr::EvaluateAsAbsolute(int64_t &Res) const {
- return EvaluateAsAbsolute(Res, 0, 0);
+ return EvaluateAsAbsolute(Res, 0, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
const MCAsmLayout &Layout) const {
- return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout);
+ return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, 0);
+}
+
+bool MCExpr::EvaluateAsAbsolute(int64_t &Res,
+ const MCAsmLayout &Layout,
+ const SectionAddrMap &Addrs) const {
+ return EvaluateAsAbsolute(Res, &Layout.getAssembler(), &Layout, &Addrs);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler &Asm) const {
- return EvaluateAsAbsolute(Res, &Asm, 0);
+ return EvaluateAsAbsolute(Res, &Asm, 0, 0);
}
bool MCExpr::EvaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm,
- const MCAsmLayout *Layout) const {
+ const MCAsmLayout *Layout,
+ const SectionAddrMap *Addrs) const {
MCValue Value;
// Fast path constants.
return true;
}
- if (!EvaluateAsRelocatableImpl(Value, Asm, Layout, false) ||
- !Value.isAbsolute()) {
- // EvaluateAsAbsolute is defined to return the "current value" of
- // the expression if we are given a Layout object, even in cases
- // when the value is not fixed.
- if (Layout) {
- Res = Value.getConstant();
- if (Value.getSymA()) {
- Res += Layout->getSymbolAddress(
- &Layout->getAssembler().getSymbolData(Value.getSymA()->getSymbol()));
- }
- if (Value.getSymB()) {
- Res -= Layout->getSymbolAddress(
- &Layout->getAssembler().getSymbolData(Value.getSymB()->getSymbol()));
- }
- }
- return false;
- }
+ // FIXME: The use if InSet = Addrs is a hack. Setting InSet causes us
+ // absolutize differences across sections and that is what the MachO writer
+ // uses Addrs for.
+ bool IsRelocatable =
+ EvaluateAsRelocatableImpl(Value, Asm, Layout, Addrs, /*InSet*/ Addrs);
+ // Record the current value.
Res = Value.getConstant();
- return true;
+
+ return IsRelocatable && Value.isAbsolute();
}
-static bool EvaluateSymbolicAdd(const MCAsmLayout *Layout,
- const MCAssembler *Asm,
- bool InSet,
- const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
- const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst,
- MCValue &Res) {
- // We can't add or subtract two symbols.
- if ((LHS.getSymA() && RHS_A) ||
- (LHS.getSymB() && RHS_B))
- return false;
+/// \brief Helper method for \see EvaluateSymbolAdd().
+static void AttemptToFoldSymbolOffsetDifference(const MCAssembler *Asm,
+ const MCAsmLayout *Layout,
+ const SectionAddrMap *Addrs,
+ bool InSet,
+ const MCSymbolRefExpr *&A,
+ const MCSymbolRefExpr *&B,
+ int64_t &Addend) {
+ if (!A || !B)
+ return;
- const MCSymbolRefExpr *A = LHS.getSymA() ? LHS.getSymA() : RHS_A;
- const MCSymbolRefExpr *B = LHS.getSymB() ? LHS.getSymB() : RHS_B;
- if (B) {
- // If we have a negated symbol, then we must have also have a non-negated
- // symbol in order to encode the expression. We can do this check later to
- // permit expressions which eventually fold to a representable form -- such
- // as (a + (0 - b)) -- if necessary.
- if (!A)
- return false;
+ const MCSymbol &SA = A->getSymbol();
+ const MCSymbol &SB = B->getSymbol();
+
+ if (SA.isUndefined() || SB.isUndefined())
+ return;
+
+ if (!Asm->getWriter().IsSymbolRefDifferenceFullyResolved(*Asm, A, B, InSet))
+ return;
+
+ MCSymbolData &AD = Asm->getSymbolData(SA);
+ MCSymbolData &BD = Asm->getSymbolData(SB);
+
+ if (AD.getFragment() == BD.getFragment()) {
+ Addend += (AD.getOffset() - BD.getOffset());
+
+ // Pointers to Thumb symbols need to have their low-bit set to allow
+ // for interworking.
+ if (Asm->isThumbFunc(&SA))
+ Addend |= 1;
+
+ // Clear the symbol expr pointers to indicate we have folded these
+ // operands.
+ A = B = 0;
+ return;
}
- // Absolutize symbol differences between defined symbols when we have a
- // layout object and the target requests it.
+ if (!Layout)
+ return;
- assert(!(Layout && !Asm));
+ const MCSectionData &SecA = *AD.getFragment()->getParent();
+ const MCSectionData &SecB = *BD.getFragment()->getParent();
- if (Asm && A && B) {
- const MCSymbol &SA = A->getSymbol();
- const MCSymbol &SB = B->getSymbol();
- const MCObjectFormat &F = Asm->getBackend().getObjectFormat();
- if (SA.isDefined() && SB.isDefined() && F.isAbsolute(InSet, SA, SB)) {
- MCSymbolData &AD = Asm->getSymbolData(A->getSymbol());
- MCSymbolData &BD = Asm->getSymbolData(B->getSymbol());
+ if ((&SecA != &SecB) && !Addrs)
+ return;
- if (AD.getFragment() == BD.getFragment()) {
- Res = MCValue::get(+ AD.getOffset()
- - BD.getOffset()
- + LHS.getConstant()
- + RHS_Cst);
- return true;
- }
+ // Eagerly evaluate.
+ Addend += (Layout->getSymbolOffset(&Asm->getSymbolData(A->getSymbol())) -
+ Layout->getSymbolOffset(&Asm->getSymbolData(B->getSymbol())));
+ if (Addrs && (&SecA != &SecB))
+ Addend += (Addrs->lookup(&SecA) - Addrs->lookup(&SecB));
- if (Layout) {
- Res = MCValue::get(+ Layout->getSymbolAddress(&AD)
- - Layout->getSymbolAddress(&BD)
- + LHS.getConstant()
- + RHS_Cst);
- return true;
- }
- }
+ // Clear the symbol expr pointers to indicate we have folded these
+ // operands.
+ A = B = 0;
+}
+
+/// \brief Evaluate the result of an add between (conceptually) two MCValues.
+///
+/// This routine conceptually attempts to construct an MCValue:
+/// Result = (Result_A - Result_B + Result_Cst)
+/// from two MCValue's LHS and RHS where
+/// Result = LHS + RHS
+/// and
+/// Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
+///
+/// This routine attempts to aggresively fold the operands such that the result
+/// is representable in an MCValue, but may not always succeed.
+///
+/// \returns True on success, false if the result is not representable in an
+/// MCValue.
+
+/// NOTE: It is really important to have both the Asm and Layout arguments.
+/// They might look redundant, but this function can be used before layout
+/// is done (see the object streamer for example) and having the Asm argument
+/// lets us avoid relaxations early.
+static bool EvaluateSymbolicAdd(const MCAssembler *Asm,
+ const MCAsmLayout *Layout,
+ const SectionAddrMap *Addrs,
+ bool InSet,
+ const MCValue &LHS,const MCSymbolRefExpr *RHS_A,
+ const MCSymbolRefExpr *RHS_B, int64_t RHS_Cst,
+ MCValue &Res) {
+ // FIXME: This routine (and other evaluation parts) are *incredibly* sloppy
+ // about dealing with modifiers. This will ultimately bite us, one day.
+ const MCSymbolRefExpr *LHS_A = LHS.getSymA();
+ const MCSymbolRefExpr *LHS_B = LHS.getSymB();
+ int64_t LHS_Cst = LHS.getConstant();
+
+ // Fold the result constant immediately.
+ int64_t Result_Cst = LHS_Cst + RHS_Cst;
+
+ assert((!Layout || Asm) &&
+ "Must have an assembler object if layout is given!");
+
+ // If we have a layout, we can fold resolved differences.
+ if (Asm) {
+ // First, fold out any differences which are fully resolved. By
+ // reassociating terms in
+ // Result = (LHS_A - LHS_B + LHS_Cst) + (RHS_A - RHS_B + RHS_Cst).
+ // we have the four possible differences:
+ // (LHS_A - LHS_B),
+ // (LHS_A - RHS_B),
+ // (RHS_A - LHS_B),
+ // (RHS_A - RHS_B).
+ // Since we are attempting to be as aggressive as possible about folding, we
+ // attempt to evaluate each possible alternative.
+ AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, LHS_B,
+ Result_Cst);
+ AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, LHS_A, RHS_B,
+ Result_Cst);
+ AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, LHS_B,
+ Result_Cst);
+ AttemptToFoldSymbolOffsetDifference(Asm, Layout, Addrs, InSet, RHS_A, RHS_B,
+ Result_Cst);
}
- Res = MCValue::get(A, B, LHS.getConstant() + RHS_Cst);
+ // We can't represent the addition or subtraction of two symbols.
+ if ((LHS_A && RHS_A) || (LHS_B && RHS_B))
+ return false;
+
+ // At this point, we have at most one additive symbol and one subtractive
+ // symbol -- find them.
+ const MCSymbolRefExpr *A = LHS_A ? LHS_A : RHS_A;
+ const MCSymbolRefExpr *B = LHS_B ? LHS_B : RHS_B;
+
+ // If we have a negated symbol, then we must have also have a non-negated
+ // symbol in order to encode the expression.
+ if (B && !A)
+ return false;
+
+ Res = MCValue::get(A, B, Result_Cst);
return true;
}
bool MCExpr::EvaluateAsRelocatable(MCValue &Res,
- const MCAsmLayout *Layout) const {
- if (Layout)
- return EvaluateAsRelocatableImpl(Res, &Layout->getAssembler(), Layout,
- false);
- else
- return EvaluateAsRelocatableImpl(Res, 0, 0, false);
+ const MCAsmLayout &Layout) const {
+ return EvaluateAsRelocatableImpl(Res, &Layout.getAssembler(), &Layout,
+ 0, false);
}
bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
const MCAssembler *Asm,
const MCAsmLayout *Layout,
+ const SectionAddrMap *Addrs,
bool InSet) const {
++stats::MCExprEvaluate;
if (Sym.isVariable() && SRE->getKind() == MCSymbolRefExpr::VK_None) {
bool Ret = Sym.getVariableValue()->EvaluateAsRelocatableImpl(Res, Asm,
Layout,
+ Addrs,
true);
// If we failed to simplify this to a constant, let the target
// handle it.
MCValue Value;
if (!AUE->getSubExpr()->EvaluateAsRelocatableImpl(Value, Asm, Layout,
- InSet))
+ Addrs, InSet))
return false;
switch (AUE->getOpcode()) {
MCValue LHSValue, RHSValue;
if (!ABE->getLHS()->EvaluateAsRelocatableImpl(LHSValue, Asm, Layout,
- InSet) ||
+ Addrs, InSet) ||
!ABE->getRHS()->EvaluateAsRelocatableImpl(RHSValue, Asm, Layout,
- InSet))
+ Addrs, InSet))
return false;
// We only support a few operations on non-constant expressions, handle
return false;
case MCBinaryExpr::Sub:
// Negate RHS and add.
- return EvaluateSymbolicAdd(Layout, Asm, InSet, LHSValue,
+ return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
RHSValue.getSymB(), RHSValue.getSymA(),
-RHSValue.getConstant(),
Res);
case MCBinaryExpr::Add:
- return EvaluateSymbolicAdd(Layout, Asm, InSet, LHSValue,
+ return EvaluateSymbolicAdd(Asm, Layout, Addrs, InSet, LHSValue,
RHSValue.getSymA(), RHSValue.getSymB(),
RHSValue.getConstant(),
Res);
assert(0 && "Invalid assembly expression kind!");
return false;
}
+
+const MCSection *MCExpr::FindAssociatedSection() const {
+ switch (getKind()) {
+ case Target:
+ // We never look through target specific expressions.
+ return cast<MCTargetExpr>(this)->FindAssociatedSection();
+
+ case Constant:
+ return MCSymbol::AbsolutePseudoSection;
+
+ case SymbolRef: {
+ const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(this);
+ const MCSymbol &Sym = SRE->getSymbol();
+
+ if (Sym.isDefined())
+ return &Sym.getSection();
+
+ return 0;
+ }
+
+ case Unary:
+ return cast<MCUnaryExpr>(this)->getSubExpr()->FindAssociatedSection();
+
+ case Binary: {
+ const MCBinaryExpr *BE = cast<MCBinaryExpr>(this);
+ const MCSection *LHS_S = BE->getLHS()->FindAssociatedSection();
+ const MCSection *RHS_S = BE->getRHS()->FindAssociatedSection();
+
+ // If either section is absolute, return the other.
+ if (LHS_S == MCSymbol::AbsolutePseudoSection)
+ return RHS_S;
+ if (RHS_S == MCSymbol::AbsolutePseudoSection)
+ return LHS_S;
+
+ // Otherwise, return the first non-null section.
+ return LHS_S ? LHS_S : RHS_S;
+ }
+ }
+
+ assert(0 && "Invalid assembly expression kind!");
+ return 0;
+}
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