Start work on object loader using llvm's RuntimeDyld api.

lib/llvm-backend/cpp/object_loader.cpp

@@ -0,0 +1,96 @@
+#include "object_loader.hh"
+#include <llvm/ExecutionEngine/RuntimeDyld.h>
+#include <iostream>
+
+class MemoryManager : llvm::RuntimeDyld::MemoryManager {
+public:
+    MemoryManager() {}
+
+    virtual ~MemoryManager() {}
+
+    virtual uint8_t* allocateCodeSection(uintptr_t Size, unsigned Alignment, unsigned SectionID, llvm::StringRef SectionName) override {
+        return nullptr;
+    }
+
+    virtual uint8_t* allocateDataSection(uintptr_t Size, unsigned Alignment, unsigned SectionID, llvm::StringRef SectionName, bool isReadOnly) override {
+        return nullptr;
+    }
+
+    virtual void reserveAllocationSpace(
+        uintptr_t code_size,
+        uint32_t code_align,
+        uintptr_t read_data_size,
+        uint32_t read_data_align,
+        uintptr_t read_write_data_size,
+        uint32_t read_write_data_align
+    ) override {
+        
+    }
+
+    /* Turn on the `reserveAllocationSpace` callback. */
+    virtual bool needsToReserveAllocationSpace() override {
+        return true;
+    }
+
+    virtual void registerEHFrames(uint8_t* Addr, uint64_t LoadAddr, size_t Size) override {
+
+    }
+
+    virtual void deregisterEHFrames() override {
+
+    }
+
+    virtual bool finalizeMemory(std::string *ErrMsg = nullptr) override {
+        
+
+        return false;
+    }
+
+    virtual void notifyObjectLoaded(llvm::RuntimeDyld &RTDyld, const llvm::object::ObjectFile &Obj) override {
+        
+    }
+private:
+    struct Section {
+        uint8_t* base;
+        size_t num_pages;
+        size_t num_commited_bytes;
+    };
+
+    uint8_t *image_base;
+    size_t num_allocated_pages;
+
+    Section code_section, read_section, readwrite_section;
+
+
+};
+
+class SymbolLookup : llvm::JITSymbolResolver {
+public:
+    virtual llvm::Expected<LookupResult> lookup(const LookupSet& symbols) override {
+        LookupResult result;
+
+        for (auto symbol : symbols) {
+            result.emplace(symbol, symbol_lookup(symbol));
+        }
+
+        return result;
+    }
+
+    virtual llvm::Expected<LookupFlagsResult> lookupFlags(const LookupSet& symbols) override {
+        LookupFlagsResult result;
+
+        for (auto symbol : symbols) {
+            result.emplace(symbol, symbol_lookup(symbol).getFlags());
+        }
+
+        return result;
+    }
+
+private:
+    llvm::JITEvaluatedSymbol symbol_lookup(llvm::StringRef name) {
+        std::cout << "symbol name: " << (std::string)name << std::endl;
+        uint64_t addr = 0;
+
+        return llvm::JITEvaluatedSymbol(addr, llvm::JITSymbolFlags::None);
+    }
+};