1 files changed, 143 insertions, 0 deletions
diff --git a/unittests/ExecutionEngine/MCJIT/SectionMemoryManager.cpp b/unittests/ExecutionEngine/MCJIT/SectionMemoryManager.cpp
new file mode 100644
index 0000000..d6baf3c
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+++ b/unittests/ExecutionEngine/MCJIT/SectionMemoryManager.cpp
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+//===-- SectionMemoryManager.cpp - The memory manager for MCJIT -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the implementation of the section-based memory manager
+// used by MCJIT.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/config.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/MathExtras.h"
+
+#include "SectionMemoryManager.h"
+
+#ifdef __linux__
+// These includes used by SectionMemoryManager::getPointerToNamedFunction()
+// for Glibc trickery. Look comments in this function for more information.
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
+namespace llvm {
+
+uint8_t *SectionMemoryManager::allocateDataSection(uintptr_t Size,
+                                                    unsigned Alignment,
+                                                    unsigned SectionID) {
+  if (!Alignment)
+    Alignment = 16;
+  // Ensure that enough memory is requested to allow aligning.
+  size_t NumElementsAligned = 1 + (Size + Alignment - 1)/Alignment;
+  uint8_t *Addr = (uint8_t*)calloc(NumElementsAligned, Alignment);
+
+  // Honour the alignment requirement.
+  uint8_t *AlignedAddr = (uint8_t*)RoundUpToAlignment((uint64_t)Addr, Alignment);
+
+  // Store the original address from calloc so we can free it later.
+  AllocatedDataMem.push_back(sys::MemoryBlock(Addr, NumElementsAligned*Alignment));
+  return AlignedAddr;
+}
+
+uint8_t *SectionMemoryManager::allocateCodeSection(uintptr_t Size,
+                                                    unsigned Alignment,
+                                                    unsigned SectionID) {
+  if (!Alignment)
+    Alignment = 16;
+  unsigned NeedAllocate = Alignment * ((Size + Alignment - 1)/Alignment + 1);
+  uintptr_t Addr = 0;
+  // Look in the list of free code memory regions and use a block there if one
+  // is available.
+  for (int i = 0, e = FreeCodeMem.size(); i != e; ++i) {
+    sys::MemoryBlock &MB = FreeCodeMem[i];
+    if (MB.size() >= NeedAllocate) {
+      Addr = (uintptr_t)MB.base();
+      uintptr_t EndOfBlock = Addr + MB.size();
+      // Align the address.
+      Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
+      // Store cutted free memory block.
+      FreeCodeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
+                                        EndOfBlock - Addr - Size);
+      return (uint8_t*)Addr;
+    }
+  }
+
+  // No pre-allocated free block was large enough. Allocate a new memory region.
+  sys::MemoryBlock MB = sys::Memory::AllocateRWX(NeedAllocate, 0, 0);
+
+  AllocatedCodeMem.push_back(MB);
+  Addr = (uintptr_t)MB.base();
+  uintptr_t EndOfBlock = Addr + MB.size();
+  // Align the address.
+  Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
+  // The AllocateRWX may allocate much more memory than we need. In this case,
+  // we store the unused memory as a free memory block.
+  unsigned FreeSize = EndOfBlock-Addr-Size;
+  if (FreeSize > 16)
+    FreeCodeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
+
+  // Return aligned address
+  return (uint8_t*)Addr;
+}
+
+void SectionMemoryManager::invalidateInstructionCache() {
+  for (int i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
+    sys::Memory::InvalidateInstructionCache(AllocatedCodeMem[i].base(),
+                                            AllocatedCodeMem[i].size());
+}
+
+void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
+                                                       bool AbortOnFailure) {
+#if defined(__linux__)
+  //===--------------------------------------------------------------------===//
+  // Function stubs that are invoked instead of certain library calls
+  //
+  // Force the following functions to be linked in to anything that uses the
+  // JIT. This is a hack designed to work around the all-too-clever Glibc
+  // strategy of making these functions work differently when inlined vs. when
+  // not inlined, and hiding their real definitions in a separate archive file
+  // that the dynamic linker can't see. For more info, search for
+  // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+  if (Name == "stat") return (void*)(intptr_t)&stat;
+  if (Name == "fstat") return (void*)(intptr_t)&fstat;
+  if (Name == "lstat") return (void*)(intptr_t)&lstat;
+  if (Name == "stat64") return (void*)(intptr_t)&stat64;
+  if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
+  if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
+  if (Name == "atexit") return (void*)(intptr_t)&atexit;
+  if (Name == "mknod") return (void*)(intptr_t)&mknod;
+#endif // __linux__
+
+  const char *NameStr = Name.c_str();
+  void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+  if (Ptr) return Ptr;
+
+  // If it wasn't found and if it starts with an underscore ('_') character,
+  // try again without the underscore.
+  if (NameStr[0] == '_') {
+    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+    if (Ptr) return Ptr;
+  }
+
+  if (AbortOnFailure)
+    report_fatal_error("Program used external function '" + Name +
+                      "' which could not be resolved!");
+  return 0;
+}
+
+SectionMemoryManager::~SectionMemoryManager() {
+  for (unsigned i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
+    sys::Memory::ReleaseRWX(AllocatedCodeMem[i]);
+  for (unsigned i = 0, e = AllocatedDataMem.size(); i != e; ++i)
+    free(AllocatedDataMem[i].base());
+}
+
+} // namespace llvm