Add support for the notion of "hidden" relocations. On MachO, these are relocation...

I'm not familiar enough with ELF or COFF to know if they should have any relocations marked hidden.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142961 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index 1ae9372bbdab8e6410257c3f695a6c63e887ad18..dcf116e6c211b629b2a86c48d2c8c77e98f22eb4 100644 (file)
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -88,6 +88,7 @@ protected:
                                                  int64_t &Res) const;
   virtual error_code getRelocationValueString(DataRefImpl Rel,
                                            SmallVectorImpl<char> &Result) const;
+  virtual error_code getRelocationHidden(DataRefImpl Rel, bool &Result) const;
 
 private:
   MachOObject *MachOObj;

diff --git a/include/llvm/Object/ObjectFile.h b/include/llvm/Object/ObjectFile.h
index 331ed7caa063596d4ce1babdf7c18e76affff99b..0c7a518305f4633f0112718afdfce8cf3be5a9bd 100644 (file)
--- a/include/llvm/Object/ObjectFile.h
+++ b/include/llvm/Object/ObjectFile.h
@@ -101,6 +101,11 @@ public:
   error_code getSymbol(SymbolRef &Result) const;
   error_code getType(uint32_t &Result) const;
 
+  /// @brief Indicates whether this relocation should hidden when listing
+  /// relocations, usually because it is the trailing part of a multipart
+  /// relocation that will be printed as part of the leading relocation.
+  error_code getHidden(bool &Result) const;
+
   /// @brief Get a string that represents the type of this relocation.
   ///
   /// This is for display purposes only.
@@ -286,6 +291,10 @@ protected:
                                                  int64_t &Res) const = 0;
   virtual error_code getRelocationValueString(DataRefImpl Rel,
                                        SmallVectorImpl<char> &Result) const = 0;
+  virtual error_code getRelocationHidden(DataRefImpl Rel, bool &Result) const {
+    Result = false;
+    return object_error::success;
+  }
 
 public:
 
@@ -483,6 +492,10 @@ inline error_code RelocationRef::getValueString(SmallVectorImpl<char> &Result)
   return OwningObject->getRelocationValueString(RelocationPimpl, Result);
 }
 
+inline error_code RelocationRef::getHidden(bool &Result) const {
+  return OwningObject->getRelocationHidden(RelocationPimpl, Result);
+}
+
 } // end namespace object
 } // end namespace llvm
 

diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 96db34f4114892b0d667d4f197fa680ecd97fa4a..a4d7cb542fb764542543fbbd0e245322acaead31 100644 (file)
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -952,6 +952,38 @@ error_code MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
   return object_error::success;
 }
 
+error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
+                                                bool &Result) const {
+  InMemoryStruct<macho::RelocationEntry> RE;
+  getRelocation(Rel, RE);
+
+  unsigned Type = (RE->Word1 >> 28) & 0xF;
+  unsigned Arch = getArch();
+
+  Result = false;
+
+  // On arches that use the generic relocations, GENERIC_RELOC_PAIR
+  // is always hidden.
+  if (Arch == Triple::x86 || Arch == Triple::arm) {
+    if (Type == 1) Result = true;
+  } else if (Arch == Triple::x86_64) {
+    // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
+    // an X864_64_RELOC_SUBTRACTOR.
+    if (Type == 0 && Rel.d.a > 0) {
+      DataRefImpl RelPrev = Rel;
+      RelPrev.d.a--;
+      InMemoryStruct<macho::RelocationEntry> REPrev;
+      getRelocation(RelPrev, REPrev);
+
+      unsigned PrevType = (REPrev->Word1 >> 28) & 0xF;
+
+      if (PrevType == 5) Result = true;
+    }
+  }
+
+  return object_error::success;
+}
+
 /*===-- Miscellaneous -----------------------------------------------------===*/
 
 uint8_t MachOObjectFile::getBytesInAddress() const {

diff --git a/tools/llvm-objdump/llvm-objdump.cpp b/tools/llvm-objdump/llvm-objdump.cpp
index c2480df14157354ae32ffc01f853aab9fa225849..c0486defa5e759b3d8de6376a612e6c4cb16d1e9 100644 (file)
--- a/tools/llvm-objdump/llvm-objdump.cpp
+++ b/tools/llvm-objdump/llvm-objdump.cpp
@@ -301,9 +301,15 @@ static void DisassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
 
         // Print relocation for instruction.
         while (rel_cur != rel_end) {
+          bool hidden = false;
           uint64_t addr;
           SmallString<16> name;
           SmallString<32> val;
+
+          // If this relocation is hidden, skip it.
+          if (error(rel_cur->getHidden(hidden))) goto skip_print_rel;
+          if (hidden) goto skip_print_rel;
+
           if (error(rel_cur->getAddress(addr))) goto skip_print_rel;
           // Stop when rel_cur's address is past the current instruction.
           if (addr >= Index + Size) break;
@@ -336,9 +342,12 @@ static void PrintRelocations(const ObjectFile *o) {
                              ri != re; ri.increment(ec)) {
       if (error(ec)) return;
 
+      bool hidden;
       uint64_t address;
       SmallString<32> relocname;
       SmallString<32> valuestr;
+      if (error(ri->getHidden(hidden))) continue;
+      if (hidden) continue;
       if (error(ri->getTypeName(relocname))) continue;
       if (error(ri->getAddress(address))) continue;
       if (error(ri->getValueString(valuestr))) continue;