[Clang Interpreter] Initial patch for the constexpr interpreter

Summary:
This patch introduces the skeleton of the constexpr interpreter,
capable of evaluating a simple constexpr functions consisting of
if statements. The interpreter is described in more detail in the
RFC. Further patches will add more features.

Reviewers: Bigcheese, jfb, rsmith

Subscribers: bruno, uenoku, ldionne, Tyker, thegameg, tschuett, dexonsmith, mgorny, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64146

llvm-svn: 370476

1 files changed, 30 insertions, 0 deletions

diff --git a/clang/lib/AST/Interp/Opcode.h b/clang/lib/AST/Interp/Opcode.h
new file mode 100644
index 00000000000..d2daa1ea52a
--- /dev/null
+++ b/clang/lib/AST/Interp/Opcode.h
@@ -0,0 +1,30 @@
+//===--- Opcode.h - Opcodes for the constexpr VM ----------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Defines all opcodes executed by the VM and emitted by the compiler.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_INTERP_OPCODE_H
+#define LLVM_CLANG_AST_INTERP_OPCODE_H
+
+#include <cstdint>
+
+namespace clang {
+namespace interp {
+
+enum Opcode : uint32_t {
+#define GET_OPCODE_NAMES
+#include "Opcodes.inc"
+#undef GET_OPCODE_NAMES
+};
+
+} // namespace interp
+} // namespace clang
+
+#endif