Extend RTDyld API to enable optionally precomputing the total amount of memory

required for all sections in a module. This can be useful when targets or
code-models place strict requirements on how sections must be laid out
in memory.

If RTDyldMemoryManger::needsToReserveAllocationSpace() is overridden to return
true then the JIT will call the following method on the memory manager, which
can be used to preallocate the necessary memory.

void RTDyldMemoryManager::reserveAllocationSpace(uintptr_t CodeSize,
                                                 uintptr_t DataSizeRO,
                                                 uintptr_t DataSizeRW)

Patch by Vaidas Gasiunas. Thanks very much Viadas!

llvm-svn: 201259

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.h b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.h
index a458356fe4b..09c1bae24e3 100644
--- a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.h
+++ b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.h
@@ -45,6 +45,15 @@ public:
     return ClientMM->allocateDataSection(Size, Alignment,
                                          SectionID, SectionName, IsReadOnly);
   }
+  
+  virtual void reserveAllocationSpace(
+    uintptr_t CodeSize, uintptr_t DataSizeRO, uintptr_t DataSizeRW) {
+    return ClientMM->reserveAllocationSpace(CodeSize, DataSizeRO, DataSizeRW);
+  }
+  
+  virtual bool needsToReserveAllocationSpace() {
+    return ClientMM->needsToReserveAllocationSpace();
+  }
 
   virtual void notifyObjectLoaded(ExecutionEngine *EE,
                                   const ObjectImage *Obj) {