In debug mode dump extra info when passing -debug -debug-only=jitfromscratch

Author: weliveindetail

CMakeLists.txt

@@ -108,8 +108,13 @@ dump_target_properties(JitFromScratch COMPILE_DEFINITIONS)
 dump_target_properties(JitFromScratch LINK_LIBRARIES)
 dump_target_properties(JitFromScratch LINK_FLAGS)
 
+# Only LLVM Debug builds can parse debug arguments
+if(${LLVM_BUILD_TYPE} STREQUAL "Debug" AND CMAKE_BUILD_TYPE STREQUAL "Debug")
+  set(debug_args -debug -debug-only=jitfromscratch)
+endif()
+
 add_custom_target(run
-  COMMAND $<TARGET_FILE:JitFromScratch>
+  COMMAND $<TARGET_FILE:JitFromScratch> ${debug_args}
   COMMENT "Running JitFromScratch"
 )
 

JitFromScratch.cpp

@@ -1,14 +1,22 @@
 #include "JitFromScratch.h"
 
 #include <llvm/ExecutionEngine/Orc/ThreadSafeModule.h>
+#include <llvm/Support/Debug.h>
+
+#define DEBUG_TYPE "jitfromscratch"
 
 using namespace llvm;
 using namespace llvm::orc;
 
-JitFromScratch::JitFromScratch(ExitOnError ExitOnErr)
-    : LLJIT(ExitOnErr(LLJITBuilder().create())) {}
+JitFromScratch::JitFromScratch(ExitOnError ExitOnErr) {
+  LLJITBuilder Builder;
+  ExitOnErr(Builder.prepareForConstruction());
+  TT = Builder.JTMB->getTargetTriple();
+  LLJIT = ExitOnErr(Builder.create());
+}
 
 Error JitFromScratch::submitModule(std::unique_ptr<Module> M,
                                    std::unique_ptr<LLVMContext> C) {
+  LLVM_DEBUG(dbgs() << "Submit IR module:\n\n" << *M << "\n\n");
   return LLJIT->addIRModule(ThreadSafeModule(std::move(M), std::move(C)));
 }

JitFromScratch.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <llvm/ADT/Triple.h>
 #include <llvm/ExecutionEngine/Orc/LLJIT.h>
 #include <llvm/IR/DataLayout.h>
 #include <llvm/IR/LLVMContext.h>
@@ -22,8 +23,13 @@ class JitFromScratch {
     return LLJIT->getDataLayout();
   }
 
+  const llvm::Triple &getTargetTriple() const {
+    return TT;
+  }
+
   llvm::Error submitModule(std::unique_ptr<llvm::Module> M,
                            std::unique_ptr<llvm::LLVMContext> C);
 private:
   std::unique_ptr<llvm::orc::LLJIT> LLJIT;
+  llvm::Triple TT;
 };

main.cpp

@@ -2,6 +2,8 @@
 #include <llvm/IR/DataLayout.h>
 #include <llvm/IR/LLVMContext.h>
 #include <llvm/IR/Module.h>
+#include <llvm/Support/CommandLine.h>
+#include <llvm/Support/Debug.h>
 #include <llvm/Support/Error.h>
 #include <llvm/Support/Format.h>
 #include <llvm/Support/InitLLVM.h>
@@ -12,6 +14,8 @@
 
 #include "JitFromScratch.h"
 
+#define DEBUG_TYPE "jitfromscratch"
+
 using namespace llvm;
 
 Expected<std::string> codegenIR(Module &module, unsigned items) {
@@ -61,11 +65,17 @@ int main(int argc, char **argv) {
   InitializeNativeTargetAsmPrinter();
   InitializeNativeTargetAsmParser();
 
+  // Parse implicit -debug and -debug-only options.
+  cl::ParseCommandLineOptions(argc, argv, "JitFromScratch example project\n");
+
   int x[]{0, 1, 2};
   int y[]{3, 1, -1};
 
   JitFromScratch Jit(ExitOnErr);
 
+  LLVM_DEBUG(dbgs() << "JITing for host target: "
+                    << Jit.getTargetTriple().normalize() << "\n\n");
+
   auto C = std::make_unique<LLVMContext>();
   auto M = std::make_unique<Module>("JitFromScratch", *C);
   M->setDataLayout(Jit.getDataLayout());

test/lit.cfg.py

@@ -10,6 +10,9 @@
 config.test_source_root = os.path.dirname(__file__)
 config.suffixes = ['.test']
 
+if config.build_type.lower() == "debug":
+  config.suffixes.append('.test-debug')
+
 # Add binary directories for JitFromScratch and FileCheck executables
 llvm_config.with_environment('PATH', config.jitfromscratch_build_dir, append_path=True)
 llvm_config.with_environment('PATH', config.llvm_tools_dir, append_path=True)

test/lit.site.cfg.py.in

@@ -6,6 +6,7 @@ config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.python_executable = "@PYTHON_EXECUTABLE@"
 config.jitfromscratch_build_dir = "@CMAKE_BINARY_DIR@/@CMAKE_CFG_INTDIR@"
+config.build_type = "@CMAKE_BUILD_TYPE@"
 
 import lit.llvm
 lit.llvm.initialize(lit_config, config)

test/stderr.test-debug

@@ -0,0 +1,11 @@
+# Check that output from LLVM_DEBUG is printed in Debug mode (dumps to stderr)
+# RUN: JitFromScratch -debug -debug-only=jitfromscratch 2>&1 | FileCheck %s
+
+# CHECK: JITing for host target: {{.*}}
+# CHECK-EMPTY:
+# CHECK-NEXT: Submit IR module:
+# CHECK-EMPTY:
+# CHECK-NEXT: ; ModuleID = 'JitFromScratch'
+# CHECK-NEXT: source_filename = "JitFromScratch"
+
+# CHECK: Integer Distances: 3, 0, 3