[llvm-commits] [llvm] r142961 - in /llvm/trunk: include/llvm/Object/MachO.h include/llvm/Object/ObjectFile.h lib/Object/MachOObjectFile.cpp tools/llvm-objdump/llvm-objdump.cpp

[Owen Anderson]

Author: resistor
Date: Tue Oct 25 15:35:53 2011
New Revision: 142961

URL: http://llvm.org/viewvc/llvm-project?rev=142961&view=rev
Log:
Add support for the notion of "hidden" relocations.  On MachO, these are relocation entries that are used as additional information for other, real relocations, rather than being relocations themselves.
I'm not familiar enough with ELF or COFF to know if they should have any relocations marked hidden.

Modified:
    llvm/trunk/include/llvm/Object/MachO.h
    llvm/trunk/include/llvm/Object/ObjectFile.h
    llvm/trunk/lib/Object/MachOObjectFile.cpp
    llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp

Modified: llvm/trunk/include/llvm/Object/MachO.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/MachO.h?rev=142961&r1=142960&r2=142961&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/MachO.h (original)
+++ llvm/trunk/include/llvm/Object/MachO.h Tue Oct 25 15:35:53 2011
@@ -88,6 +88,7 @@
                                                  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;

Modified: llvm/trunk/include/llvm/Object/ObjectFile.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ObjectFile.h?rev=142961&r1=142960&r2=142961&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ObjectFile.h (original)
+++ llvm/trunk/include/llvm/Object/ObjectFile.h Tue Oct 25 15:35:53 2011
@@ -101,6 +101,11 @@
   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 @@
                                                  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 @@
   return OwningObject->getRelocationValueString(RelocationPimpl, Result);
 }
 
+inline error_code RelocationRef::getHidden(bool &Result) const {
+  return OwningObject->getRelocationHidden(RelocationPimpl, Result);
+}
+
 } // end namespace object
 } // end namespace llvm
 

Modified: llvm/trunk/lib/Object/MachOObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/MachOObjectFile.cpp?rev=142961&r1=142960&r2=142961&view=diff
==============================================================================
--- llvm/trunk/lib/Object/MachOObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/MachOObjectFile.cpp Tue Oct 25 15:35:53 2011
@@ -952,6 +952,38 @@
   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 {

Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp?rev=142961&r1=142960&r2=142961&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp Tue Oct 25 15:35:53 2011
@@ -301,9 +301,15 @@
 
         // 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 @@
                              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;