Moving SectionMemoryManager into RuntimeDyld and adding unit tests for it.

The SectionMemoryManager now supports (and requires) applying section-specific page permissions.  Clients using this memory manager must call either MCJIT::finalizeObject() or SectionMemoryManager::applyPermissions() before executing JITed code.

See r168718 for changes from the previous implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168721 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 176 insertions, 0 deletions

diff --git a/include/llvm/ExecutionEngine/SectionMemoryManager.h b/include/llvm/ExecutionEngine/SectionMemoryManager.h
new file mode 100644
index 0000000..ba4ba8d0
--- /dev/null
+++ b/include/llvm/ExecutionEngine/SectionMemoryManager.h
@@ -0,0 +1,176 @@
+//===- SectionMemoryManager.h - Memory manager for MCJIT/RtDyld -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the declaration of a section-based memory manager used by
+// the MCJIT execution engine and RuntimeDyld.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H
+#define LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Memory.h"
+
+namespace llvm {
+
+/// This is a simple memory manager which implements the methods called by
+/// the RuntimeDyld class to allocate memory for section-based loading of
+/// objects, usually those generated by the MCJIT execution engine.
+///
+/// This memory manager allocates all section memory as read-write.  The
+/// RuntimeDyld will copy JITed section memory into these allocated blocks
+/// and perform any necessary linking and relocations.
+///
+/// Any client using this memory manager MUST ensure that section-specific
+/// page permissions have been applied before attempting to execute functions
+/// in the JITed object.  Permissions can be applied either by calling
+/// MCJIT::finalizeObject or by calling SectionMemoryManager::applyPermissions
+/// directly.  Clients of MCJIT should call MCJIT::finalizeObject.
+class SectionMemoryManager : public JITMemoryManager {
+  SectionMemoryManager(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
+  void operator=(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
+
+public:
+  SectionMemoryManager() { }
+  virtual ~SectionMemoryManager();
+
+  /// \brief Allocates a memory block of (at least) the given size suitable for
+  /// executable code.
+  ///
+  /// The value of \p Alignment must be a power of two.  If \p Alignment is zero
+  /// a default alignment of 16 will be used.
+  virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
+                                       unsigned SectionID);
+
+  /// \brief Allocates a memory block of (at least) the given size suitable for
+  /// executable code.
+  ///
+  /// The value of \p Alignment must be a power of two.  If \p Alignment is zero
+  /// a default alignment of 16 will be used.
+  virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
+                                       unsigned SectionID,
+                                       bool isReadOnly);
+
+  /// \brief Applies section-specific memory permissions.
+  ///
+  /// This method is called when object loading is complete and section page
+  /// permissions can be applied.  It is up to the memory manager implementation
+  /// to decide whether or not to act on this method.  The memory manager will
+  /// typically allocate all sections as read-write and then apply specific
+  /// permissions when this method is called.  Code sections cannot be executed
+  /// until this function has been called.
+  ///
+  /// \returns true if an error occurred, false otherwise.
+  virtual bool applyPermissions(std::string *ErrMsg = 0);
+
+  /// This method returns the address of the specified function. As such it is
+  /// only useful for resolving library symbols, not code generated symbols.
+  ///
+  /// If \p AbortOnFailure is false and no function with the given name is
+  /// found, this function returns a null pointer. Otherwise, it prints a
+  /// message to stderr and aborts.
+  virtual void *getPointerToNamedFunction(const std::string &Name,
+                                          bool AbortOnFailure = true);
+
+  /// \brief Invalidate instruction cache for code sections.
+  ///
+  /// Some platforms with separate data cache and instruction cache require
+  /// explicit cache flush, otherwise JIT code manipulations (like resolved
+  /// relocations) will get to the data cache but not to the instruction cache.
+  ///
+  /// This method is not called by RuntimeDyld or MCJIT during the load
+  /// process.  Clients may call this function when needed.  See the lli
+  /// tool for example use.
+  virtual void invalidateInstructionCache();
+
+private:
+  struct MemoryGroup {
+      SmallVector<sys::MemoryBlock, 16> AllocatedMem;
+      SmallVector<sys::MemoryBlock, 16> FreeMem;
+      sys::MemoryBlock Near;
+  };
+
+  uint8_t *allocateSection(MemoryGroup &MemGroup, uintptr_t Size,
+                           unsigned Alignment);
+
+  error_code applyMemoryGroupPermissions(MemoryGroup &MemGroup,
+                                         unsigned Permissions);
+
+  MemoryGroup CodeMem;
+  MemoryGroup RWDataMem;
+  MemoryGroup RODataMem;
+
+public:
+  ///
+  /// Functions below are not used by MCJIT or RuntimeDyld, but must be
+  /// implemented because they are declared as pure virtuals in the base class.
+  ///
+
+  virtual void setMemoryWritable() {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual void setMemoryExecutable() {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual void setPoisonMemory(bool poison) {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual void AllocateGOT() {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual uint8_t *getGOTBase() const {
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual uint8_t *startFunctionBody(const Function *F,
+                                     uintptr_t &ActualSize){
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual uint8_t *allocateStub(const GlobalValue *F, unsigned StubSize,
+                                unsigned Alignment) {
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
+                               uint8_t *FunctionEnd) {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual void deallocateFunctionBody(void *Body) {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual uint8_t *startExceptionTable(const Function *F,
+                                       uintptr_t &ActualSize) {
+    llvm_unreachable("Unexpected call!");
+    return 0;
+  }
+  virtual void endExceptionTable(const Function *F, uint8_t *TableStart,
+                                 uint8_t *TableEnd, uint8_t *FrameRegister) {
+    llvm_unreachable("Unexpected call!");
+  }
+  virtual void deallocateExceptionTable(void *ET) {
+    llvm_unreachable("Unexpected call!");
+  }
+};
+
+}
+
+#endif // LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H
+