1 files changed, 75 insertions, 6 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 3ce7e8d..ecdd227 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -321,6 +321,11 @@ static cl::alias SymbolTableShort("t", cl::desc("Alias for --syms"),
                                   cl::NotHidden, cl::Grouping,
                                   cl::aliasopt(SymbolTable));
 
+static cl::opt<bool> SymbolizeOperands(
+    "symbolize-operands",
+    cl::desc("Symbolize instruction operands when disassembling"),
+    cl::cat(ObjdumpCat));
+
 static cl::opt<bool> DynamicSymbolTable(
     "dynamic-syms",
     cl::desc("Display the contents of the dynamic symbol table"),
@@ -1578,6 +1583,42 @@ static SymbolInfoTy createDummySymbolInfo(const ObjectFile *Obj,
     return SymbolInfoTy(Addr, Name, Type);
 }
 
+static void
+collectLocalBranchTargets(ArrayRef<uint8_t> Bytes, const MCInstrAnalysis *MIA,
+                          MCDisassembler *DisAsm, MCInstPrinter *IP,
+                          const MCSubtargetInfo *STI, uint64_t SectionAddr,
+                          uint64_t Start, uint64_t End,
+                          std::unordered_map<uint64_t, std::string> &Labels) {
+  // So far only supports X86.
+  if (!STI->getTargetTriple().isX86())
+    return;
+
+  Labels.clear();
+  unsigned LabelCount = 0;
+  Start += SectionAddr;
+  End += SectionAddr;
+  uint64_t Index = Start;
+  while (Index < End) {
+    // Disassemble a real instruction and record function-local branch labels.
+    MCInst Inst;
+    uint64_t Size;
+    bool Disassembled = DisAsm->getInstruction(
+        Inst, Size, Bytes.slice(Index - SectionAddr), Index, nulls());
+    if (Size == 0)
+      Size = 1;
+
+    if (Disassembled && MIA) {
+      uint64_t Target;
+      bool TargetKnown = MIA->evaluateBranch(Inst, Index, Size, Target);
+      if (TargetKnown && (Target >= Start && Target < End) &&
+          !Labels.count(Target))
+        Labels[Target] = ("L" + Twine(LabelCount++)).str();
+    }
+
+    Index += Size;
+  }
+}
+
 static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
                               MCContext &Ctx, MCDisassembler *PrimaryDisAsm,
                               MCDisassembler *SecondaryDisAsm,
@@ -1894,6 +1935,12 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
                              !DisassembleAll;
       bool DumpARMELFData = false;
       formatted_raw_ostream FOS(outs());
+
+      std::unordered_map<uint64_t, std::string> AllLabels;
+      if (SymbolizeOperands)
+        collectLocalBranchTargets(Bytes, MIA, DisAsm, IP, PrimarySTI,
+                                  SectionAddr, Index, End, AllLabels);
+
       while (Index < End) {
         // ARM and AArch64 ELF binaries can interleave data and text in the
         // same section. We rely on the markers introduced to understand what
@@ -1934,6 +1981,11 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
             }
           }
 
+          // Print local label if there's any.
+          auto Iter = AllLabels.find(SectionAddr + Index);
+          if (Iter != AllLabels.end())
+            FOS << "<" << Iter->second << ">:\n";
+
           // Disassemble a real instruction or a data when disassemble all is
           // provided
           MCInst Inst;
@@ -1967,7 +2019,9 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
                           Inst, SectionAddr + Index, Size)) {
                 Target = *MaybeTarget;
                 PrintTarget = true;
-                FOS << "  # " << Twine::utohexstr(Target);
+                // Do not print real address when symbolizing.
+                if (!SymbolizeOperands)
+                  FOS << "  # " << Twine::utohexstr(Target);
               }
             if (PrintTarget) {
               // In a relocatable object, the target's section must reside in
@@ -2017,17 +2071,30 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
                 }
               }
 
+              // Print the labels corresponding to the target if there's any.
+              bool LabelAvailable = AllLabels.count(Target);
               if (TargetSym != nullptr) {
                 uint64_t TargetAddress = TargetSym->Addr;
+                uint64_t Disp = Target - TargetAddress;
                 std::string TargetName = TargetSym->Name.str();
                 if (Demangle)
                   TargetName = demangle(TargetName);
 
-                FOS << " <" << TargetName;
-                uint64_t Disp = Target - TargetAddress;
-                if (Disp)
-                  FOS << "+0x" << Twine::utohexstr(Disp);
-                FOS << '>';
+                FOS << " <";
+                if (!Disp) {
+                  // Always Print the binary symbol precisely corresponding to
+                  // the target address.
+                  FOS << TargetName;
+                } else if (!LabelAvailable) {
+                  // Always Print the binary symbol plus an offset if there's no
+                  // local label corresponding to the target address.
+                  FOS << TargetName << "+0x" << Twine::utohexstr(Disp);
+                } else {
+                  FOS << AllLabels[Target];
+                }
+                FOS << ">";
+              } else if (LabelAvailable) {
+                FOS << " <" << AllLabels[Target] << ">";
               }
             }
           }
@@ -2149,6 +2216,8 @@ static void disassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
                 "no instruction printer for target " + TripleName);
   IP->setPrintImmHex(PrintImmHex);
   IP->setPrintBranchImmAsAddress(true);
+  IP->setSymbolizeOperands(SymbolizeOperands);
+  IP->setMCInstrAnalysis(MIA.get());
 
   PrettyPrinter &PIP = selectPrettyPrinter(Triple(TripleName));
   SourcePrinter SP(Obj, TheTarget->getName());