Add minimal JIT compiler based on LLJIT

Author: weliveindetail

CMakeLists.txt

@@ -38,6 +38,7 @@ endif()
 
 add_executable(JitFromScratch
   main.cpp
+  JitFromScratch.cpp
 )
 
 target_include_directories(JitFromScratch PRIVATE
@@ -48,6 +49,7 @@ target_include_directories(JitFromScratch PRIVATE
 set(llvm_libs
   LLVMAggressiveInstCombine
   LLVMAnalysis
+  LLVMAsmParser
   LLVMAsmPrinter
   LLVMBinaryFormat
   LLVMBitReader
@@ -59,14 +61,21 @@ set(llvm_libs
   LLVMDebugInfoDWARF
   LLVMDebugInfoMSF
   LLVMDemangle
+  LLVMExecutionEngine
   LLVMGlobalISel
   LLVMInstCombine
+  LLVMInstrumentation
+  LLVMJITLink
+  LLVMLinker
+  LLVMIRReader
   LLVMMC
   LLVMMCDisassembler
   LLVMMCParser
   LLVMObject
+  LLVMOrcJIT
   LLVMProfileData
   LLVMRemarks
+  LLVMRuntimeDyld
   LLVMScalarOpts
   LLVMSelectionDAG
   LLVMSupport

JitFromScratch.cpp

@@ -0,0 +1,7 @@
+#include "JitFromScratch.h"
+
+using namespace llvm;
+using namespace llvm::orc;
+
+JitFromScratch::JitFromScratch(ExitOnError ExitOnErr)
+    : LLJIT(ExitOnErr(LLJITBuilder().create())) {}

JitFromScratch.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <llvm/ExecutionEngine/Orc/LLJIT.h>
+
+#include <memory>
+
+class JitFromScratch {
+public:
+  JitFromScratch(llvm::ExitOnError ExitOnErr);
+
+  // Not a value type.
+  JitFromScratch(const JitFromScratch &) = delete;
+  JitFromScratch &operator=(const JitFromScratch &) = delete;
+  JitFromScratch(JitFromScratch &&) = delete;
+  JitFromScratch &operator=(JitFromScratch &&) = delete;
+
+private:
+  std::unique_ptr<llvm::orc::LLJIT> LLJIT;
+};

main.cpp

@@ -1,8 +1,15 @@
+#include <llvm/ExecutionEngine/ExecutionEngine.h>
+#include <llvm/IR/DataLayout.h>
+#include <llvm/Support/Error.h>
 #include <llvm/Support/Format.h>
 #include <llvm/Support/InitLLVM.h>
 #include <llvm/Support/TargetSelect.h>
 #include <llvm/Support/raw_ostream.h>
 
+#include <memory>
+
+#include "JitFromScratch.h"
+
 using namespace llvm;
 
 // Determine the size of a C array at compile-time.
@@ -41,12 +48,18 @@ int *integerDistances(const int (&x)[sizeOfArray], int *y) {
 int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
 
+  ExitOnError ExitOnErr;
+  ExitOnErr.setBanner("JitFromScratch: ");
+
   InitializeNativeTarget();
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
 
   int x[]{0, 1, 2};
   int y[]{3, 1, -1};
+
+  JitFromScratch Jit(ExitOnErr);
+
   int *z = integerDistances(x, y);
 
   outs() << format("Integer Distances: %d, %d, %d\n\n", z[0], z[1], z[2]);