[NFCI][ELF] Merge AddendOnly and AddendOnlyWithTargetVA

The former is just a special case of the latter, ignoring the expr and
always just using the addend, allowing (and enforcing) the sym is null.
If we just use dummySym then we don't need to maintain this as a
separate case, since R_ADDEND will return the addend unmodified for the
call to getRelocTargetVA.

Reviewers: MaskRay, arichardson

Reviewed By: MaskRay, arichardson

Pull Request: #150797

Author: jrtc27

lld/ELF/Relocations.cpp

@@ -887,7 +887,7 @@ static void addPltEntry(Ctx &ctx, PltSection &plt, GotPltSection &gotPlt,
   gotPlt.addEntry(sym);
   rel.addReloc({type, &gotPlt, sym.getGotPltOffset(ctx),
                 sym.isPreemptible ? DynamicReloc::AgainstSymbol
-                                  : DynamicReloc::AddendOnlyWithTargetVA,
+                                  : DynamicReloc::AddendOnly,
                 sym, 0, R_ABS});
 }
 
@@ -927,8 +927,8 @@ static void addGotAuthEntry(Ctx &ctx, Symbol &sym) {
 
   // Signed GOT requires dynamic relocation.
   ctx.in.got->getPartition(ctx).relaDyn->addReloc(
-      {R_AARCH64_AUTH_RELATIVE, ctx.in.got.get(), off,
-       DynamicReloc::AddendOnlyWithTargetVA, sym, 0, R_ABS});
+      {R_AARCH64_AUTH_RELATIVE, ctx.in.got.get(), off, DynamicReloc::AddendOnly,
+       sym, 0, R_ABS});
 }
 
 static void addTpOffsetGotEntry(Ctx &ctx, Symbol &sym) {
@@ -1160,8 +1160,8 @@ void RelocationScanner::processAux(RelExpr expr, RelType type, uint64_t offset,
           part.relrAuthDyn->relocs.push_back({sec, sec->relocs().size() - 1});
         } else {
           part.relaDyn->addReloc({R_AARCH64_AUTH_RELATIVE, sec, offset,
-                                  DynamicReloc::AddendOnlyWithTargetVA, sym,
-                                  addend, R_ABS});
+                                  DynamicReloc::AddendOnly, sym, addend,
+                                  R_ABS});
         }
         return;
       }

lld/ELF/SyntheticSections.cpp

@@ -1122,8 +1122,8 @@ void MipsGotSection::build() {
     for (const std::pair<GotEntry, size_t> &p : got.local16) {
       uint64_t offset = p.second * ctx.arg.wordsize;
       ctx.mainPart->relaDyn->addReloc({ctx.target->relativeRel, this, offset,
-                                       DynamicReloc::AddendOnlyWithTargetVA,
-                                       *p.first.first, p.first.second, R_ABS});
+                                       DynamicReloc::AddendOnly, *p.first.first,
+                                       p.first.second, R_ABS});
     }
   }
 }
@@ -1650,17 +1650,14 @@ int64_t DynamicReloc::computeAddend(Ctx &ctx) const {
   case Computed:
     llvm_unreachable("addend already computed");
   case AddendOnly:
-    assert(sym == nullptr);
-    return addend;
-  case AgainstSymbol:
-    assert(sym != nullptr);
-    return addend;
-  case AddendOnlyWithTargetVA:
   case AgainstSymbolWithTargetVA: {
     uint64_t ca = inputSec->getRelocTargetVA(
         ctx, Relocation{expr, type, 0, addend, sym}, getOffset());
     return ctx.arg.is64 ? ca : SignExtend64<32>(ca);
   }
+  case AgainstSymbol:
+    assert(sym != nullptr);
+    return addend;
   case MipsMultiGotPage:
     assert(sym == nullptr);
     return getMipsPageAddr(outputSec->addr) + addend;
@@ -1705,8 +1702,8 @@ void RelocationBaseSection::addAddendOnlyRelocIfNonPreemptible(
     addReloc({dynType, &isec, offsetInSec, DynamicReloc::AgainstSymbol, sym, 0,
               R_ABS});
   else
-    addReloc(DynamicReloc::AddendOnlyWithTargetVA, dynType, isec, offsetInSec,
-             sym, 0, R_ABS, addendRelType);
+    addReloc(DynamicReloc::AddendOnly, dynType, isec, offsetInSec, sym, 0,
+             R_ABS, addendRelType);
 }
 
 void RelocationBaseSection::mergeRels() {

lld/ELF/SyntheticSections.h

@@ -422,13 +422,10 @@ class DynamicReloc {
     /// The resulting dynamic relocation has already had its addend computed.
     /// Calling computeAddend() is an error. Only for internal use.
     Computed,
-    /// The resulting dynamic relocation does not reference a symbol (#sym must
-    /// be nullptr) and uses #addend as the result of computeAddend(ctx).
-    AddendOnly,
     /// The resulting dynamic relocation will not reference a symbol: #sym is
     /// only used to compute the addend with InputSection::getRelocTargetVA().
     /// Useful for various relative and TLS relocations (e.g. R_X86_64_TPOFF64).
-    AddendOnlyWithTargetVA,
+    AddendOnly,
     /// The resulting dynamic relocation references symbol #sym from the dynamic
     /// symbol table and uses #addend as the value of computeAddend(ctx).
     AgainstSymbol,
@@ -441,7 +438,7 @@ class DynamicReloc {
     /// addresses of 64kb pages that lie inside the output section.
     MipsMultiGotPage,
   };
-  /// This constructor records a relocation against a symbol.
+  /// This constructor records a normal relocation.
   DynamicReloc(RelType type, const InputSectionBase *inputSec,
                uint64_t offsetInSec, Kind kind, Symbol &sym, int64_t addend,
                RelExpr expr)
@@ -450,8 +447,9 @@ class DynamicReloc {
   /// This constructor records a relative relocation with no symbol.
   DynamicReloc(RelType type, const InputSectionBase *inputSec,
                uint64_t offsetInSec, int64_t addend = 0)
-      : sym(nullptr), inputSec(inputSec), offsetInSec(offsetInSec), type(type),
-        addend(addend), kind(AddendOnly), expr(R_ADDEND) {}
+      : sym(inputSec->getCtx().dummySym), inputSec(inputSec),
+        offsetInSec(offsetInSec), type(type), addend(addend), kind(AddendOnly),
+        expr(R_ADDEND) {}
   /// This constructor records dynamic relocation settings used by the MIPS
   /// multi-GOT implementation.
   DynamicReloc(RelType type, const InputSectionBase *inputSec,
@@ -532,8 +530,8 @@ class RelocationBaseSection : public SyntheticSection {
                         uint64_t offsetInSec, Symbol &sym, int64_t addend,
                         RelType addendRelType, RelExpr expr) {
     assert(expr != R_ADDEND && "expected non-addend relocation expression");
-    addReloc<shard>(DynamicReloc::AddendOnlyWithTargetVA, dynType, isec,
-                    offsetInSec, sym, addend, expr, addendRelType);
+    addReloc<shard>(DynamicReloc::AddendOnly, dynType, isec, offsetInSec, sym,
+                    addend, expr, addendRelType);
   }
   /// Add a dynamic relocation using the target address of \p sym as the addend
   /// if \p sym is non-preemptible. Otherwise add a relocation against \p sym.

lld/ELF/Writer.cpp

@@ -1586,8 +1586,7 @@ template <class ELFT> void Writer<ELFT>::finalizeAddressDependentContent() {
               if (isInt<32>(reloc.sym->getVA(ctx, reloc.addend)))
                 return false;
               part.relaDyn->addReloc({R_AARCH64_AUTH_RELATIVE, elem.inputSec,
-                                      reloc.offset,
-                                      DynamicReloc::AddendOnlyWithTargetVA,
+                                      reloc.offset, DynamicReloc::AddendOnly,
                                       *reloc.sym, reloc.addend, R_ABS});
               return true;
             });