Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/lib/ExecutionEngine/Interpreter/Interpreter.cpp

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+//===- Interpreter.cpp - Top-Level LLVM Interpreter Implementation --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the top-level functionality for the LLVM interpreter.
+// This interpreter is designed to be a very simple, portable, inefficient
+// interpreter.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Interpreter.h"
+#include "llvm/CodeGen/IntrinsicLowering.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Module.h"
+#include <cstring>
+using namespace llvm;
+
+namespace {
+
+static struct RegisterInterp {
+  RegisterInterp() { Interpreter::Register(); }
+} InterpRegistrator;
+
+}
+
+extern "C" void LLVMLinkInInterpreter() { }
+
+/// Create a new interpreter object.
+///
+ExecutionEngine *Interpreter::create(std::unique_ptr<Module> M,
+                                     std::string *ErrStr) {
+  // Tell this Module to materialize everything and release the GVMaterializer.
+  if (Error Err = M->materializeAll()) {
+    std::string Msg;
+    handleAllErrors(std::move(Err), [&](ErrorInfoBase &EIB) {
+      Msg = EIB.message();
+    });
+    if (ErrStr)
+      *ErrStr = Msg;
+    // We got an error, just return 0
+    return nullptr;
+  }
+
+  return new Interpreter(std::move(M));
+}
+
+//===----------------------------------------------------------------------===//
+// Interpreter ctor - Initialize stuff
+//
+Interpreter::Interpreter(std::unique_ptr<Module> M)
+    : ExecutionEngine(std::move(M)) {
+
+  memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped));
+  // Initialize the "backend"
+  initializeExecutionEngine();
+  initializeExternalFunctions();
+  emitGlobals();
+
+  IL = new IntrinsicLowering(getDataLayout());
+}
+
+Interpreter::~Interpreter() {
+  delete IL;
+}
+
+void Interpreter::runAtExitHandlers () {
+  while (!AtExitHandlers.empty()) {
+    callFunction(AtExitHandlers.back(), None);
+    AtExitHandlers.pop_back();
+    run();
+  }
+}
+
+/// run - Start execution with the specified function and arguments.
+///
+GenericValue Interpreter::runFunction(Function *F,
+                                      ArrayRef<GenericValue> ArgValues) {
+  assert (F && "Function *F was null at entry to run()");
+
+  // Try extra hard not to pass extra args to a function that isn't
+  // expecting them.  C programmers frequently bend the rules and
+  // declare main() with fewer parameters than it actually gets
+  // passed, and the interpreter barfs if you pass a function more
+  // parameters than it is declared to take. This does not attempt to
+  // take into account gratuitous differences in declared types,
+  // though.
+  const size_t ArgCount = F->getFunctionType()->getNumParams();
+  ArrayRef<GenericValue> ActualArgs =
+      ArgValues.slice(0, std::min(ArgValues.size(), ArgCount));
+
+  // Set up the function call.
+  callFunction(F, ActualArgs);
+
+  // Start executing the function.
+  run();
+
+  return ExitValue;
+}