Add support to the JIT for true non-lazy operation. When a call to a function

that has not been JIT'd yet, the callee is put on a list of pending functions
to JIT.  The call is directed through a stub, which is updated with the address
of the function after it has been JIT'd.  A new interface for allocating and
updating empty stubs is provided.

Add support for removing the ModuleProvider the JIT was created with, which
would otherwise invalidate the JIT's PassManager, which is initialized with the
ModuleProvider's Module.

Add support under a new ExecutionEngine flag for emitting the infomration 
necessary to update Function and GlobalVariable stubs after JITing them, by
recording the address of the stub and the name of the GlobalValue.  This allows
code to be copied from one address space to another, where libraries may live
at different virtual addresses, and have the stubs updated with their new
correct target addresses.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64906 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/ExecutionEngine/JIT/JITMemoryManager.cpp b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
index cc072a896c..0dcc71f837 100644
--- a/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
+++ b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
@@ -258,6 +258,7 @@ namespace {
     
     unsigned char *CurStubPtr, *StubBase;
     unsigned char *GOTBase;      // Target Specific reserved memory
+    void *DlsymTable;            // Stub external symbol information
 
     // Centralize memory block allocation.
     sys::MemoryBlock getNewMemoryBlock(unsigned size);
@@ -269,7 +270,8 @@ namespace {
     ~DefaultJITMemoryManager();
 
     void AllocateGOT();
-
+    void SetDlsymTable(void *);
+    
     unsigned char *allocateStub(const GlobalValue* F, unsigned StubSize,
                                 unsigned Alignment);
     
@@ -343,6 +345,10 @@ namespace {
       return GOTBase;
     }
     
+    void *getDlsymTable() const {
+      return DlsymTable;
+    }
+    
     /// deallocateMemForFunction - Deallocate all memory for the specified
     /// function body.
     void deallocateMemForFunction(const Function *F) {
@@ -463,6 +469,7 @@ DefaultJITMemoryManager::DefaultJITMemoryManager() {
   FreeMemoryList = Mem0;
 
   GOTBase = NULL;
+  DlsymTable = NULL;
 }
 
 void DefaultJITMemoryManager::AllocateGOT() {
@@ -471,6 +478,9 @@ void DefaultJITMemoryManager::AllocateGOT() {
   HasGOT = true;
 }
 
+void DefaultJITMemoryManager::SetDlsymTable(void *ptr) {
+  DlsymTable = ptr;
+}
 
 DefaultJITMemoryManager::~DefaultJITMemoryManager() {
   for (unsigned i = 0, e = Blocks.size(); i != e; ++i)