[WebAssembly] Implement eliminateCallFramePseudo

[oota-llvm.git] / lib / MC / MCAssembler.cpp

diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index d93bf44928ddc2057f80129a1b7dd34d3a127ebf..9f3ab18a40b485294b51c978834f6c9b3abb4beb 100644 (file)
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -97,17 +97,17 @@ void MCAsmLayout::invalidateFragmentsFrom(MCFragment *F) {
 
 void MCAsmLayout::ensureValid(const MCFragment *F) const {
   MCSection *Sec = F->getParent();
-  MCFragment *Cur = LastValidFragment[Sec];
-  if (!Cur)
-    Cur = Sec->begin();
+  MCSection::iterator I;
+  if (MCFragment *Cur = LastValidFragment[Sec])
+    I = ++MCSection::iterator(Cur);
   else
-    Cur = Cur->getNextNode();
+    I = Sec->begin();
 
   // Advance the layout position until the fragment is valid.
   while (!isFragmentValid(F)) {
-    assert(Cur && "Layout bookkeeping error");
-    const_cast<MCAsmLayout*>(this)->layoutFragment(Cur);
-    Cur = Cur->getNextNode();
+    assert(I != Sec->end() && "Layout bookkeeping error");
+    const_cast<MCAsmLayout *>(this)->layoutFragment(&*I);
+    ++I;
   }
 }
 
@@ -179,14 +179,19 @@ const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const {
 
   const MCExpr *Expr = Symbol.getVariableValue();
   MCValue Value;
-  if (!Expr->evaluateAsValue(Value, *this))
-    llvm_unreachable("Invalid Expression");
+  if (!Expr->evaluateAsValue(Value, *this)) {
+    Assembler.getContext().reportError(
+        SMLoc(), "expression could not be evaluated");
+    return nullptr;
+  }
 
   const MCSymbolRefExpr *RefB = Value.getSymB();
-  if (RefB)
-    Assembler.getContext().reportFatalError(
+  if (RefB) {
+    Assembler.getContext().reportError(
         SMLoc(), Twine("symbol '") + RefB->getSymbol().getName() +
                      "' could not be evaluated in a subtraction expression");
+    return nullptr;
+  }
 
   const MCSymbolRefExpr *A = Value.getSymA();
   if (!A)
@@ -196,9 +201,10 @@ const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const {
   const MCAssembler &Asm = getAssembler();
   if (ASym.isCommon()) {
     // FIXME: we should probably add a SMLoc to MCExpr.
-    Asm.getContext().reportFatalError(SMLoc(),
-                                "Common symbol " + ASym.getName() +
-                                    " cannot be used in assignment expr");
+    Asm.getContext().reportError(SMLoc(),
+                                 "Common symbol '" + ASym.getName() +
+                                     "' cannot be used in assignment expr");
+    return nullptr;
   }
 
   return &ASym;
@@ -277,7 +283,7 @@ MCFragment::MCFragment(FragmentType Kind, bool HasInstructions,
     : Kind(Kind), HasInstructions(HasInstructions), AlignToBundleEnd(false),
       BundlePadding(BundlePadding), Parent(Parent), Atom(nullptr),
       Offset(~UINT64_C(0)) {
-  if (Parent)
+  if (Parent && !isDummy())
     Parent->getFragmentList().push_back(this);
 }
 
@@ -319,6 +325,9 @@ void MCFragment::destroy() {
     case FT_SafeSEH:
       delete cast<MCSafeSEHFragment>(this);
       return;
+    case FT_Dummy:
+      delete cast<MCDummyFragment>(this);
+      return;
   }
 }
 
@@ -411,7 +420,7 @@ const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const {
     return &S;
 
   // Absolute and undefined symbols have no defining atom.
-  if (!S.getFragment())
+  if (!S.isInSection())
     return nullptr;
 
   // Non-linker visible symbols in sections which can't be atomized have no
@@ -433,8 +442,13 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
   // probably merge the two into a single callback that tries to evaluate a
   // fixup and records a relocation if one is needed.
   const MCExpr *Expr = Fixup.getValue();
-  if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup))
-    getContext().reportFatalError(Fixup.getLoc(), "expected relocatable expression");
+  if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) {
+    getContext().reportError(Fixup.getLoc(), "expected relocatable expression");
+    // Claim to have completely evaluated the fixup, to prevent any further
+    // processing from being done.
+    Value = 0;
+    return true;
+  }
 
   bool IsPCRel = Backend.getFixupKindInfo(
     Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
@@ -530,12 +544,19 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
 
   case MCFragment::FT_Org: {
     const MCOrgFragment &OF = cast<MCOrgFragment>(F);
-    int64_t TargetLocation;
-    if (!OF.getOffset().evaluateAsAbsolute(TargetLocation, Layout))
+    MCValue Value;
+    if (!OF.getOffset().evaluateAsValue(Value, Layout))
       report_fatal_error("expected assembly-time absolute expression");
 
     // FIXME: We need a way to communicate this error.
     uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
+    int64_t TargetLocation = Value.getConstant();
+    if (const MCSymbolRefExpr *A = Value.getSymA()) {
+      uint64_t Val;
+      if (!Layout.getSymbolOffset(A->getSymbol(), Val))
+        report_fatal_error("expected absolute expression");
+      TargetLocation += Val;
+    }
     int64_t Size = TargetLocation - FragmentOffset;
     if (Size < 0 || Size >= 0x40000000)
       report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
@@ -547,6 +568,8 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
     return cast<MCDwarfLineAddrFragment>(F).getContents().size();
   case MCFragment::FT_DwarfFrame:
     return cast<MCDwarfCallFrameFragment>(F).getContents().size();
+  case MCFragment::FT_Dummy:
+    llvm_unreachable("Should not have been added");
   }
 
   llvm_unreachable("invalid fragment kind");
@@ -780,6 +803,8 @@ static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
     OW->writeBytes(CF.getContents());
     break;
   }
+  case MCFragment::FT_Dummy:
+    llvm_unreachable("Should not have been added");
   }
 
   assert(OW->getStream().tell() - Start == FragmentSize &&
@@ -1088,7 +1113,7 @@ bool MCAssembler::layoutSectionOnce(MCAsmLayout &Layout, MCSection &Sec) {
       break;
     }
     if (RelaxedFrag && !FirstRelaxedFragment)
-      FirstRelaxedFragment = I;
+      FirstRelaxedFragment = &*I;
   }
   if (FirstRelaxedFragment) {
     Layout.invalidateFragmentsFrom(FirstRelaxedFragment);
@@ -1147,6 +1172,9 @@ void MCFragment::dump() {
   case MCFragment::FT_DwarfFrame: OS << "MCDwarfCallFrameFragment"; break;
   case MCFragment::FT_LEB:   OS << "MCLEBFragment"; break;
   case MCFragment::FT_SafeSEH:    OS << "MCSafeSEHFragment"; break;
+  case MCFragment::FT_Dummy:
+    OS << "MCDummyFragment";
+    break;
   }
 
   OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
@@ -1245,6 +1273,8 @@ void MCFragment::dump() {
     OS << " Sym:" << F->getSymbol();
     break;
   }
+  case MCFragment::FT_Dummy:
+    break;
   }
   OS << ">";
 }