enable logging IR via env variable

HOBBES_IR_TRACE_FILE: file that IR will be stored
morganstanley · Mar 19, 2023 · b93b46b · b93b46b
1 parent dc4ec73
commit b93b46b
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Showing 2 changed files with 49 additions and 3 deletions.
diff --git a/include/hobbes/eval/jitcc.H b/include/hobbes/eval/jitcc.H
@@ -9,6 +9,7 @@
 #include <hobbes/util/llvm.H>
 #include <hobbes/eval/func.H>
 #include <hobbes/eval/ctype.H>
+#include <memory>
 
 #if LLVM_VERSION_MAJOR >= 11
 #include <llvm/IR/ValueHandle.h>
@@ -260,6 +261,9 @@ private:
 #if LLVM_VERSION_MAJOR >= 11
   std::unique_ptr<ORCJIT> orcjit;
 #endif
+
+  struct IrTracer;
+  std::unique_ptr<IrTracer> irTracer;
 };
 
 // shorthand for compilation over a sequence of expressions

diff --git a/lib/hobbes/eval/jitcc.C b/lib/hobbes/eval/jitcc.C
@@ -1,4 +1,5 @@
 
+#include <cstdint>
 #include <hobbes/eval/func.H>
 #include <hobbes/util/llvm.H>
 #include <hobbes/eval/cexpr.H>
@@ -12,10 +13,17 @@
 #include <llvm/IR/LLVMContext.h>
 #include <llvm/IR/Value.h>
 #include <llvm/IR/ValueHandle.h>
+#include <llvm/IR/ValueSymbolTable.h>
 #include <llvm/Support/Casting.h>
 #include <llvm/Support/Compiler.h>
 #include <llvm/Support/Error.h>
+#include <llvm/Support/raw_os_ostream.h>
+#include <llvm/Support/raw_ostream.h>
 #include <llvm/Target/TargetMachine.h>
+
+#include <fstream>
+#include <ostream>
+#include <sstream>
 #include <stdexcept>
 #include <utility>
 
@@ -546,11 +554,43 @@ private:
 };
 #endif
 
+struct jitcc::IrTracer {
+  IrTracer() {
+    std::error_code ec;
+    const char* name = std::getenv("HOBBES_IR_TRACE_FILE");
+    if (name == nullptr) {
+      return;
+    }
+    out = std::make_unique<llvm::raw_fd_ostream>(name, ec);
+    if (ec != std::errc()) {
+      out = nullptr;
+      return;
+    }
+  }
+
+  void log(const llvm::Module& m) {
+    if (!isEnabled()) {
+      return;
+    }
+
+    m.print(*out, nullptr, false, true);
+  }
+
+private:
+  [[nodiscard]] bool isEnabled() const noexcept {
+    return !!out;
+  }
+
+  std::unique_ptr<llvm::raw_fd_ostream> out;
+};
+
 #if LLVM_VERSION_MAJOR >= 11
 jitcc::jitcc(const TEnvPtr& tenv)
     : tenv(tenv), vtenv(std::make_unique<VTEnv>()), ignoreLocalScope(false),
       globals(std::make_unique<Globals>()), globalData(32768 /* min global page size = 32K */),
-      constants(std::make_unique<ConstantList>()) {
+      constants(std::make_unique<ConstantList>()),
+      irTracer(std::make_unique<IrTracer>())
+       {
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmParser();
   llvm::InitializeNativeTargetAsmPrinter();
@@ -579,7 +619,8 @@ jitcc::~jitcc() {
 jitcc::jitcc(const TEnvPtr& tenv) :
   tenv(tenv),
   ignoreLocalScope(false),
-  globalData(32768 /* min global page size = 32K */)
+  globalData(32768 /* min global page size = 32K */),
+  irTracer(std::make_unique<IrTracer>())
 {
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmParser();
@@ -743,6 +784,7 @@ void* jitcc::getMachineCode(llvm::Function* f, llvm::JITEventListener* listener)
   if (!this->currentModule) {
     throw std::runtime_error("Internal compiler error, can't derive machine code for unknown function");
   }
+  irTracer->log(*this->currentModule);
 
   // make a new execution engine out of this module (finalizing the module)
   std::string err;
@@ -792,7 +834,7 @@ void* jitcc::getMachineCode(llvm::Function* f, llvm::JITEventListener* listener)
   ee->finalizeObject();
 
   // now we can't touch this module again
-  this->currentModule = 0;
+  this->currentModule = nullptr;
 
   // and _now_ we must be able to get machine code for this function
   void* pf = ee->getPointerToFunction(f);