Re-factored RuntimeDyLd:

1. The main works will made in the RuntimeDyLdImpl with uses the ObjectFile class. RuntimeDyLdMachO and RuntimeDyLdELF now only parses relocations and resolve it. This is allows to make improvements of the RuntimeDyLd more easily. In addition the support for COFF can be easily added.

2. Added ARM relocations to RuntimeDyLdELF.

3. Added support for stub functions for the ARM, allowing to do a long branch.

4. Added support for external functions that are not loaded from the object files, but can be loaded from external libraries. Now MCJIT can correctly execute the code containing the printf, putc, and etc.

5. The sections emitted instead functions, thanks Jim Grosbach. MemoryManager.startFunctionBody() and MemoryManager.endFunctionBody() have been removed.
6. MCJITMemoryManager.allocateDataSection() and MCJITMemoryManager. allocateCodeSection() used JMM->allocateSpace() instead of JMM->allocateCodeSection() and JMM->allocateDataSection(), because I got an error: "Cannot allocate an allocated block!" with object file contains more than one code or data sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153754 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ExecutionEngine/RuntimeDyld.h

@@ -45,17 +45,6 @@ class RTDyldMemoryManager {
   virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
                                        unsigned SectionID) = 0;
 
-  // Allocate ActualSize bytes, or more, for the named function. Return
-  // a pointer to the allocated memory and update Size to reflect how much
-  // memory was acutally allocated.
-  virtual uint8_t *startFunctionBody(const char *Name, uintptr_t &Size) = 0;
-
-  // Mark the end of the function, including how much of the allocated
-  // memory was actually used.
-  virtual void endFunctionBody(const char *Name, uint8_t *FunctionStart,
-                               uint8_t *FunctionEnd) = 0;
-
-
   virtual void *getPointerToNamedFunction(const std::string &Name,
                                           bool AbortOnFailure = true) = 0;
 };

lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h

@@ -34,53 +34,19 @@ class MCJITMemoryManager : public RTDyldMemoryManager {
 
   uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
                                unsigned SectionID) {
-    return JMM->allocateDataSection(Size, Alignment, SectionID);
+    return JMM->allocateSpace(Size, Alignment);
   }
 
   uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
                                unsigned SectionID) {
-    return JMM->allocateCodeSection(Size, Alignment, SectionID);
+    return JMM->allocateSpace(Size, Alignment);
   }
 
   virtual void *getPointerToNamedFunction(const std::string &Name,
                                           bool AbortOnFailure = true) {
     return JMM->getPointerToNamedFunction(Name, AbortOnFailure);
   }
 
-  // Allocate ActualSize bytes, or more, for the named function. Return
-  // a pointer to the allocated memory and update Size to reflect how much
-  // memory was acutally allocated.
-  uint8_t *startFunctionBody(const char *Name, uintptr_t &Size) {
-    // FIXME: This should really reference the MCAsmInfo to get the global
-    //        prefix.
-    if (Name[0] == '_') ++Name;
-    Function *F = M->getFunction(Name);
-    // Some ObjC names have a prefixed \01 in the IR. If we failed to find
-    // the symbol and it's of the ObjC conventions (starts with "-" or
-    // "+"), try prepending a \01 and see if we can find it that way.
-    if (!F && (Name[0] == '-' || Name[0] == '+'))
-      F = M->getFunction((Twine("\1") + Name).str());
-    assert(F && "No matching function in JIT IR Module!");
-    return JMM->startFunctionBody(F, Size);
-  }
-
-  // Mark the end of the function, including how much of the allocated
-  // memory was actually used.
-  void endFunctionBody(const char *Name, uint8_t *FunctionStart,
-                       uint8_t *FunctionEnd) {
-    // FIXME: This should really reference the MCAsmInfo to get the global
-    //        prefix.
-    if (Name[0] == '_') ++Name;
-    Function *F = M->getFunction(Name);
-    // Some ObjC names have a prefixed \01 in the IR. If we failed to find
-    // the symbol and it's of the ObjC conventions (starts with "-" or
-    // "+"), try prepending a \01 and see if we can find it that way.
-    if (!F && (Name[0] == '-' || Name[0] == '+'))
-      F = M->getFunction((Twine("\1") + Name).str());
-    assert(F && "No matching function in JIT IR Module!");
-    JMM->endFunctionBody(F, FunctionStart, FunctionEnd);
-  }
-
 };
 
 } // End llvm namespace

lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -26,45 +26,290 @@ RuntimeDyldImpl::~RuntimeDyldImpl() {}
 
 namespace llvm {
 
-void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
-                                      uint8_t *EndAddress) {
-  // FIXME: DEPRECATED in favor of by-section allocation.
-  // Allocate memory for the function via the memory manager.
-  uintptr_t Size = EndAddress - StartAddress + 1;
-  uintptr_t AllocSize = Size;
-  uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), AllocSize);
-  assert(Size >= (uint64_t)(EndAddress - StartAddress + 1) &&
-         "Memory manager failed to allocate enough memory!");
-  // Copy the function payload into the memory block.
-  memcpy(Mem, StartAddress, Size);
-  MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size);
-  // Remember where we put it.
-  unsigned SectionID = Sections.size();
-  Sections.push_back(sys::MemoryBlock(Mem, Size));
+namespace {
+  // Helper for extensive error checking in debug builds.
+  error_code Check(error_code Err) {
+    if (Err) {
+      report_fatal_error(Err.message());
+    }
+    return Err;
+  }
+} // end anonymous namespace
 
-  // Default the assigned address for this symbol to wherever this
-  // allocated it.
-  SymbolTable[Name] = SymbolLoc(SectionID, 0);
-  DEBUG(dbgs() << "    allocated to [" << Mem << ", " << Mem + Size << "]\n");
-}
 
 // Resolve the relocations for all symbols we currently know about.
 void RuntimeDyldImpl::resolveRelocations() {
+  // First, resolve relocations assotiated with external symbols.
+  resolveSymbols();
+
   // Just iterate over the sections we have and resolve all the relocations
   // in them. Gross overkill, but it gets the job done.
   for (int i = 0, e = Sections.size(); i != e; ++i) {
-    reassignSectionAddress(i, SectionLoadAddress[i]);
+    reassignSectionAddress(i, Sections[i].LoadAddress);
   }
 }
 
 void RuntimeDyldImpl::mapSectionAddress(void *LocalAddress,
                                         uint64_t TargetAddress) {
-  assert(SectionLocalMemToID.count(LocalAddress) &&
-         "Attempting to remap address of unknown section!");
-  unsigned SectionID = SectionLocalMemToID[LocalAddress];
-  reassignSectionAddress(SectionID, TargetAddress);
+  for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
+    if (Sections[i].Address == LocalAddress) {
+      reassignSectionAddress(i, TargetAddress);
+      return;
+    }
+  }
+  llvm_unreachable("Attempting to remap address of unknown section!");
+}
+
+bool RuntimeDyldImpl::loadObject(const MemoryBuffer *InputBuffer) {
+  // FIXME: ObjectFile don't modify MemoryBuffer.
+  //        It should use const MemoryBuffer as parameter.
+  ObjectFile *obj
+    = ObjectFile::createObjectFile(const_cast<MemoryBuffer*>(InputBuffer));
+
+  Arch = (Triple::ArchType)obj->getArch();
+
+  LocalSymbolMap LocalSymbols;     // Functions and data symbols from the
+                                   // object file.
+  ObjSectionToIDMap LocalSections; // Used sections from the object file
+
+  error_code err;
+  // Parse symbols
+  DEBUG(dbgs() << "Parse symbols:\n");
+  for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols();
+       i != e; i.increment(err)) {
+    Check(err);
+    object::SymbolRef::Type SymType;
+    StringRef Name;
+    Check(i->getType(SymType));
+    Check(i->getName(Name));
+
+    if (SymType == object::SymbolRef::ST_Function ||
+        SymType == object::SymbolRef::ST_Data) {
+      uint64_t FileOffset;
+      uint32_t flags;
+      StringRef sData;
+      section_iterator si = obj->end_sections();
+      Check(i->getFileOffset(FileOffset));
+      Check(i->getFlags(flags));
+      Check(i->getSection(si));
+      if (si == obj->end_sections()) continue;
+      Check(si->getContents(sData));
+      const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() +
+                              (uintptr_t)FileOffset;
+      uintptr_t SectOffset = (uintptr_t)(SymPtr - (const uint8_t*)sData.begin());
+      unsigned SectionID
+        = findOrEmitSection(*si,
+                          SymType == object::SymbolRef::ST_Function,
+                          LocalSections);
+      bool isGlobal = flags & SymbolRef::SF_Global;
+      LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset);
+      DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset)
+                   << " flags: " << flags
+                   << " SID: " << SectionID
+                   << " Offset: " << format("%p", SectOffset));
+      if (isGlobal)
+        SymbolTable[Name] = SymbolLoc(SectionID, SectOffset);
+    }
+    DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n");
+  }
+
+  // Parse and proccess relocations
+  DEBUG(dbgs() << "Parse relocations:\n");
+  for (section_iterator si = obj->begin_sections(),
+       se = obj->end_sections(); si != se; si.increment(err)) {
+    Check(err);
+    bool isFirstRelocation = true;
+    unsigned SectionID = 0;
+    StubMap Stubs;
+
+    for (relocation_iterator i = si->begin_relocations(),
+         e = si->end_relocations(); i != e; i.increment(err)) {
+      Check(err);
+
+      // If it's first relocation in this section, find its SectionID
+      if (isFirstRelocation) {
+        SectionID = findOrEmitSection(*si, true, LocalSections);
+        DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n");
+        isFirstRelocation = false;
+      }
+
+      ObjRelocationInfo RI;
+      RI.SectionID = SectionID;
+      Check(i->getAdditionalInfo(RI.AdditionalInfo));
+      Check(i->getOffset(RI.Offset));
+      Check(i->getSymbol(RI.Symbol));
+      Check(i->getType(RI.Type));
+
+      DEBUG(dbgs() << "\t\tAddend: " << RI.AdditionalInfo
+                   << " Offset: " << format("%p", (uintptr_t)RI.Offset)
+                   << " Type: " << (uint32_t)(RI.Type & 0xffffffffL)
+                   << "\n");
+      processRelocationRef(RI, *obj, LocalSections, LocalSymbols, Stubs);
+    }
+  }
+  return false;
+}
+
+unsigned RuntimeDyldImpl::emitSection(const SectionRef &Section,
+                                      bool IsCode) {
+
+  unsigned StubBufSize = 0,
+           StubSize = getMaxStubSize();
+  error_code err;
+  if (StubSize > 0) {
+    for (relocation_iterator i = Section.begin_relocations(),
+         e = Section.end_relocations(); i != e; i.increment(err))
+      StubBufSize += StubSize;
+  }
+  StringRef data;
+  uint64_t Alignment64;
+  Check(Section.getContents(data));
+  Check(Section.getAlignment(Alignment64));
+
+  unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL;
+  unsigned DataSize = data.size();
+  unsigned Allocate = DataSize + StubBufSize;
+  unsigned SectionID = Sections.size();
+  const char *pData = data.data();
+  uint8_t *Addr = IsCode
+    ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID)
+    : MemMgr->allocateDataSection(Allocate, Alignment, SectionID);
+
+  memcpy(Addr, pData, DataSize);
+  DEBUG(dbgs() << "emitSection SectionID: " << SectionID
+               << " obj addr: " << format("%p", pData)
+               << " new addr: " << format("%p", Addr)
+               << " DataSize: " << DataSize
+               << " StubBufSize: " << StubBufSize
+               << " Allocate: " << Allocate
+               << "\n");
+  Sections.push_back(SectionEntry(Addr, Allocate, DataSize,(uintptr_t)pData));
+  return SectionID;
+}
+
+unsigned RuntimeDyldImpl::findOrEmitSection(const SectionRef &Section,
+                                            bool IsCode,
+                                            ObjSectionToIDMap &LocalSections) {
+
+  unsigned SectionID = 0;
+  ObjSectionToIDMap::iterator i = LocalSections.find(Section);
+  if (i != LocalSections.end())
+    SectionID = i->second;
+  else {
+    SectionID = emitSection(Section, IsCode);
+    LocalSections[Section] = SectionID;
+  }
+  return SectionID;
+}
+
+void RuntimeDyldImpl::AddRelocation(const RelocationValueRef &Value,
+                                   unsigned SectionID, uintptr_t Offset,
+                                   uint32_t RelType) {
+  DEBUG(dbgs() << "AddRelocation SymNamePtr: " << format("%p", Value.SymbolName)
+               << " SID: " << Value.SectionID
+               << " Addend: " << format("%p", Value.Addend)
+               << " Offset: " << format("%p", Offset)
+               << " RelType: " << format("%x", RelType)
+               << "\n");
+
+  if (Value.SymbolName == 0) {
+    Relocations[Value.SectionID].push_back(RelocationEntry(
+      SectionID,
+      Offset,
+      RelType,
+      Value.Addend));
+  } else
+    SymbolRelocations[Value.SymbolName].push_back(RelocationEntry(
+      SectionID,
+      Offset,
+      RelType,
+      Value.Addend));
+}
+
+uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) {
+  // TODO: There is only ARM far stub now. We should add the Thumb stub,
+  // and stubs for branches Thumb - ARM and ARM - Thumb.
+  if (Arch == Triple::arm) {
+    uint32_t *StubAddr = (uint32_t*)Addr;
+    *StubAddr = 0xe51ff004; // ldr pc,<label>
+    return (uint8_t*)++StubAddr;
+  }
+  else
+    return Addr;
 }
 
+// Assign an address to a symbol name and resolve all the relocations
+// associated with it.
+void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID,
+                                             uint64_t Addr) {
+  // The address to use for relocation resolution is not
+  // the address of the local section buffer. We must be doing
+  // a remote execution environment of some sort. Re-apply any
+  // relocations referencing this section with the given address.
+  //
+  // Addr is a uint64_t because we can't assume the pointer width
+  // of the target is the same as that of the host. Just use a generic
+  // "big enough" type.
+  Sections[SectionID].LoadAddress = Addr;
+  DEBUG(dbgs() << "Resolving relocations Section #" << SectionID
+          << "\t" << format("%p", (uint8_t *)Addr)
+          << "\n");
+  resolveRelocationList(Relocations[SectionID], Addr);
+}
+
+void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE,
+                                             uint64_t Value) {
+    uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset;
+    DEBUG(dbgs() << "\tSectionID: " << RE.SectionID
+          << " + " << RE.Offset << " (" << format("%p", Target) << ")"
+          << " Data: " << RE.Data
+          << " Addend: " << RE.Addend
+          << "\n");
+
+    resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset,
+                      Value, RE.Data, RE.Addend);
+}
+
+void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs,
+                                            uint64_t Value) {
+  for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
+    resolveRelocationEntry(Relocs[i], Value);
+  }
+}
+
+// resolveSymbols - Resolve any relocations to the specified symbols if
+// we know where it lives.
+void RuntimeDyldImpl::resolveSymbols() {
+  StringMap<RelocationList>::iterator i = SymbolRelocations.begin(),
+                                      e = SymbolRelocations.end();
+  for (; i != e; i++) {
+    StringRef Name = i->first();
+    RelocationList &Relocs = i->second;
+    StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name);
+    if (Loc == SymbolTable.end()) {
+      // This is an external symbol, try to get it address from
+      // MemoryManager.
+      uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(),
+                                                                   true);
+      DEBUG(dbgs() << "Resolving relocations Name: " << Name
+              << "\t" << format("%p", Addr)
+              << "\n");
+      resolveRelocationList(Relocs, (uintptr_t)Addr);
+    } else {
+      // Change the relocation to be section relative rather than symbol
+      // relative and move it to the resolved relocation list.
+      DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
+      for (int i = 0, e = Relocs.size(); i != e; ++i) {
+        RelocationEntry Entry = Relocs[i];
+        Entry.Addend += Loc->second.second;
+        Relocations[Loc->second.first].push_back(Entry);
+      }
+      Relocs.clear();
+    }
+  }
+}
+
+
 //===----------------------------------------------------------------------===//
 // RuntimeDyld class implementation
 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {