Initial overlay of HQEMU 2.5.2 changes onto underlying 2.5.1 QEMU GIT tree2.5.1_overlay

1 files changed, 318 insertions, 0 deletions

diff --git a/llvm/include/JITMemoryManager.h b/llvm/include/JITMemoryManager.h
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+//===-- JITMemoryManager.cpp - Memory Allocator for JIT'd code ------------===//
+//
+//                     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 DefaultJITMemoryManager class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __JITMEMORYMANAGER_H
+#define __JITMEMORYMANAGER_H
+
+#include <sys/mman.h>
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm-debug.h"
+#include "utils.h"
+
+using namespace llvm;
+
+#define MIN_CODE_CACHE_SIZE         (1 * 1024 * 1024)
+#define DEFAULT_GLOBAL_SIZE         (64 * 1024)
+#define DEFAULT_THRESHOLD           (32 * 1024)
+
+
+// AtExitHandlers - List of functions to call when the program exits,
+// registered with the atexit() library function.
+static std::vector<void (*)()> AtExitHandlers;
+
+/// runAtExitHandlers - Run any functions registered by the program's
+/// calls to atexit(3), which we intercept and store in
+/// AtExitHandlers.
+///
+static void runAtExitHandlers() {
+  while (!AtExitHandlers.empty()) {
+    void (*Fn)() = AtExitHandlers.back();
+    AtExitHandlers.pop_back();
+    Fn();
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// 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 defined(__linux__) && defined(__GLIBC__)
+/* stat functions are redirecting to __xstat with a version number.  On x86-64
+ * linking with libc_nonshared.a and -Wl,--export-dynamic doesn't make 'stat'
+ * available as an exported symbol, so we have to add it explicitly.
+ */
+namespace {
+class StatSymbols {
+public:
+  StatSymbols() {
+    sys::DynamicLibrary::AddSymbol("stat", (void*)(intptr_t)stat);
+    sys::DynamicLibrary::AddSymbol("fstat", (void*)(intptr_t)fstat);
+    sys::DynamicLibrary::AddSymbol("lstat", (void*)(intptr_t)lstat);
+    sys::DynamicLibrary::AddSymbol("stat64", (void*)(intptr_t)stat64);
+    sys::DynamicLibrary::AddSymbol("\x1stat64", (void*)(intptr_t)stat64);
+    sys::DynamicLibrary::AddSymbol("\x1open64", (void*)(intptr_t)open64);
+    sys::DynamicLibrary::AddSymbol("\x1lseek64", (void*)(intptr_t)lseek64);
+    sys::DynamicLibrary::AddSymbol("fstat64", (void*)(intptr_t)fstat64);
+    sys::DynamicLibrary::AddSymbol("lstat64", (void*)(intptr_t)lstat64);
+    sys::DynamicLibrary::AddSymbol("atexit", (void*)(intptr_t)atexit);
+    sys::DynamicLibrary::AddSymbol("mknod", (void*)(intptr_t)mknod);
+  }
+};
+}
+static StatSymbols initStatSymbols;
+#endif // __linux__
+
+// jit_exit - Used to intercept the "exit" library call.
+static void jit_exit(int Status) {
+  runAtExitHandlers();   // Run atexit handlers...
+  exit(Status);
+}
+
+// jit_atexit - Used to intercept the "atexit" library call.
+static int jit_atexit(void (*Fn)()) {
+  AtExitHandlers.push_back(Fn);    // Take note of atexit handler...
+  return 0;  // Always successful
+}
+
+static int jit_noop() {
+  return 0;
+}
+
+
+/// DefaultJITMemoryManager - Manage trace cache memory  for the JIT code generation.
+class DefaultJITMemoryManager : public JITMemoryManager {
+  uint8_t *TraceCache;
+  size_t TraceCacheSize;
+
+  uint8_t *GlobalBase;  /* section for global data used by QEMU helpers */
+  uint8_t *CodeBase;    /* section for emitting trace code */
+  uint8_t *CodeGenPtr;
+
+  size_t GlobalRemain;
+  size_t CodeRemain;
+  size_t Threshold;
+
+  hqemu::Mutex lock;
+
+public:
+  DefaultJITMemoryManager(uint8_t *Cache, size_t Size)
+    : TraceCache(Cache), TraceCacheSize(Size), Threshold(DEFAULT_THRESHOLD)
+  {
+    GlobalBase = TraceCache;
+    GlobalRemain = DEFAULT_GLOBAL_SIZE;
+ 
+    CodeBase = GlobalBase + DEFAULT_GLOBAL_SIZE;
+    CodeBase = (uint8_t *)(((uintptr_t)CodeBase + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
+    CodeRemain = (uintptr_t)TraceCache + TraceCacheSize - (uintptr_t)CodeBase;
+    CodeGenPtr = CodeBase;
+  }
+
+  ~DefaultJITMemoryManager() {}
+
+  //===----------------------------------------------------------------------===//
+  //
+  /// getPointerToNamedFunction - This method returns the address of the specified
+  /// function by using the dynamic loader interface.  As such it is only useful
+  /// for resolving library symbols, not code generated symbols.
+  ///
+  void *getPointerToNamedFunction(const std::string &Name,
+                                  bool AbortOnFailure = true) override {
+    // Check to see if this is one of the functions we want to intercept.  Note,
+    // we cast to intptr_t here to silence a -pedantic warning that complains
+    // about casting a function pointer to a normal pointer.
+    if (Name == "exit") return (void*)(intptr_t)&jit_exit;
+    if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
+  
+    // We should not invoke parent's ctors/dtors from generated main()!
+    // On Mingw and Cygwin, the symbol __main is resolved to
+    // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
+    // (and register wrong callee's dtors with atexit(3)).
+    // We expect ExecutionEngine::runStaticConstructorsDestructors()
+    // is called before ExecutionEngine::runFunctionAsMain() is called.
+    if (Name == "__main") return (void*)(intptr_t)&jit_noop;
+  
+    const char *NameStr = Name.c_str();
+    // If this is an asm specifier, skip the sentinal.
+    if (NameStr[0] == 1) ++NameStr;
+  
+    // If it's an external function, look it up in the process image...
+    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;
+    }
+  
+    // Darwin/PPC adds $LDBLStub suffixes to various symbols like printf.  These
+    // are references to hidden visibility symbols that dlsym cannot resolve.
+    // If we have one of these, strip off $LDBLStub and try again.
+#if defined(__APPLE__) && defined(__ppc__)
+    if (Name.size() > 9 && Name[Name.size()-9] == '$' &&
+        memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) {
+      // First try turning $LDBLStub into $LDBL128. If that fails, strip it off.
+      // This mirrors logic in libSystemStubs.a.
+      std::string Prefix = std::string(Name.begin(), Name.end()-9);
+      if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128", false))
+        return Ptr;
+      if (void *Ptr = getPointerToNamedFunction(Prefix, false))
+        return Ptr;
+    }
+#endif
+  
+    if (AbortOnFailure) {
+      report_fatal_error("Program used external function '"+Name+
+                        "' which could not be resolved!");
+    }
+    return nullptr;
+  }
+
+  void AllocateGOT() override { hqemu_error("fixme.\n"); }
+
+  // Testing methods.
+  bool CheckInvariants(std::string &ErrorStr) override { hqemu_error("fixme.\n"); return false; }
+  size_t GetDefaultCodeSlabSize() override { hqemu_error("fixme.\n"); return 0; }
+  size_t GetDefaultDataSlabSize() override { hqemu_error("fixme.\n"); return 0; }
+  size_t GetDefaultStubSlabSize() override { hqemu_error("fixme.\n"); return 0; }
+  unsigned GetNumCodeSlabs() override { hqemu_error("fixme.\n"); return 0; }
+  unsigned GetNumDataSlabs() override { hqemu_error("fixme.\n"); return 0; }
+  unsigned GetNumStubSlabs() override { hqemu_error("fixme.\n"); return 0; }
+
+  /// startFunctionBody - When a function starts, allocate a block of free
+  /// executable memory, returning a pointer to it and its actual size.
+  uint8_t *startFunctionBody(const Function *F,
+                             uintptr_t &ActualSize) override {
+    lock.acquire();
+    if (unlikely(CodeRemain < Threshold))
+      hqemu_error("internal error (fixme).\n");
+
+    ActualSize = CodeRemain;
+    return CodeGenPtr;
+  }
+
+  /// endFunctionBody - The function F is now allocated, and takes the memory
+  /// in the range [FunctionStart,FunctionEnd).
+  void endFunctionBody(const Function *F, uint8_t *FunctionStart,
+                       uint8_t *FunctionEnd) override {
+    assert(FunctionEnd > FunctionStart);
+
+    size_t GenSize = FunctionEnd - FunctionStart;
+    if (unlikely(GenSize > CodeRemain))
+        hqemu_error("exceeds available cache size.\n");
+
+    CodeGenPtr = (uint8_t *)(((uintptr_t)CodeGenPtr + GenSize + CODE_GEN_ALIGN - 1)
+                             & ~(CODE_GEN_ALIGN - 1));
+    CodeRemain = (uintptr_t)TraceCache + TraceCacheSize - (uintptr_t)CodeGenPtr;
+    lock.release();
+  }
+
+  /// allocateSpace - Allocate a memory block of the given size.  This method
+  /// cannot be called between calls to startFunctionBody and endFunctionBody.
+  uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) override {
+    hqemu_error("fixme.\n");
+    return nullptr;
+  }
+
+  /// allocateStub - Allocate memory for a function stub.
+  uint8_t *allocateStub(const GlobalValue* F, unsigned StubSize,
+                        unsigned Alignment) override {
+    return allocateGlobal(StubSize, Alignment);
+  }
+
+  /// allocateGlobal - Allocate memory for a global.
+  uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) override {
+    hqemu::MutexGuard locked(lock);
+
+    if (!Alignment)
+      Alignment = 16;
+    if (Alignment & (Alignment - 1))
+      hqemu_error("alignment must be a power of two.\n");
+
+    unsigned MisAligned = ((intptr_t)GlobalBase & (Alignment - 1));
+    if (MisAligned)
+      MisAligned = Alignment - MisAligned;
+
+    if (GlobalRemain < Size + MisAligned)
+      hqemu_error("exceeds available global size.\n");
+
+    uint8_t *GlobalPtr = GlobalBase + MisAligned;
+    GlobalBase = GlobalPtr + Size;
+    GlobalRemain -= (Size + MisAligned);
+    return GlobalPtr;
+  }
+
+  /// allocateCodeSection - Allocate memory for a code section.
+  uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
+                               unsigned SectionID,
+                               StringRef SectionName) override {
+    hqemu_error("fixme.\n"); return nullptr;
+  }
+
+  /// allocateDataSection - Allocate memory for a data section.
+  uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
+                               unsigned SectionID, StringRef SectionName,
+                               bool IsReadOnly) override {
+    hqemu_error("fixme.\n"); return nullptr;
+  }
+
+  bool finalizeMemory(std::string *ErrMsg) override { return false; }
+
+  uint8_t *getGOTBase() const override { return nullptr; }
+
+  void deallocateBlock(void *Block) {}
+
+  /// deallocateFunctionBody - Deallocate all memory for the specified
+  /// function body.
+  void deallocateFunctionBody(void *Body) override {}
+
+  /// setMemoryWritable - When code generation is in progress,
+  /// the code pages may need permissions changed.
+  void setMemoryWritable() override {}
+  /// setMemoryExecutable - When code generation is done and we're ready to
+  /// start execution, the code pages may need permissions changed.
+  void setMemoryExecutable() override {}
+
+  /// setPoisonMemory - Controls whether we write garbage over freed memory.
+  ///
+  void setPoisonMemory(bool poison) override {}
+
+  size_t getCodeSize()      { return CodeGenPtr - CodeBase; }
+  bool isSizeAvailable()    {
+    hqemu::MutexGuard locked(lock);
+    return CodeRemain >= Threshold ? 1 : 0;
+  }
+  void Flush() {
+    CodeGenPtr = CodeBase;
+    CodeRemain = (uintptr_t)TraceCache + TraceCacheSize - (uintptr_t)CodeBase;
+  }
+
+  static DefaultJITMemoryManager *Create(uint8_t *Cache, size_t Size) {
+    if (Size < MIN_CODE_CACHE_SIZE)
+      hqemu_error("Trace cache size is too small.\n");
+    return new DefaultJITMemoryManager(Cache, Size);
+  }
+};
+
+#endif
+
+/*
+ * vim: ts=8 sts=4 sw=4 expandtab
+ */