[SandboxVec] Implement Pass class

This patch implements the Pass base class and the FunctionPass sub-class that
operate on Sandbox IR.

Author: vporpo

llvm/include/llvm/SandboxIR/Pass.h

@@ -0,0 +1,82 @@
+//===- Pass.h ---------------------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASS_H
+#define LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASS_H
+
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm::sandboxir {
+
+class Function;
+
+/// The base class of a Sandbox IR Pass.
+class Pass {
+public:
+  enum class ClassID : unsigned {
+    FunctionPass,
+  };
+  static const char *getSubclassIDStr(ClassID ID) {
+    switch (ID) {
+    case ClassID::FunctionPass:
+      return "FunctionPass";
+    }
+    llvm_unreachable("Unimplemented ID");
+  }
+
+protected:
+  /// The pass name.
+  const std::string Name;
+  /// The command-line flag used to specify that this pass should run.
+  const std::string Flag;
+  /// Used for isa/cast/dyn_cast.
+  ClassID SubclassID;
+
+public:
+  Pass(StringRef Name, StringRef Flag, ClassID SubclassID)
+      : Name(Name), Flag(Flag), SubclassID(SubclassID) {}
+  virtual ~Pass() {}
+  /// \Returns the name of the pass.
+  StringRef getName() const { return Name; }
+  /// \Returns the command-line flag used to enable the pass.
+  StringRef getFlag() const { return Flag; }
+  ClassID getSubclassID() const { return SubclassID; }
+#ifndef NDEBUG
+  friend raw_ostream &operator<<(raw_ostream &OS, const Pass &Pass) {
+    Pass.dump(OS);
+    return OS;
+  }
+  void dump(raw_ostream &OS) const { OS << Name << " " << Flag; }
+  LLVM_DUMP_METHOD void dump() const;
+#endif
+};
+
+/// A pass that runs on a sandbox::Function.
+class FunctionPass : public Pass {
+protected:
+  FunctionPass(StringRef Name, StringRef Flag, ClassID PassID)
+      : Pass(Name, Flag, PassID) {}
+
+public:
+  FunctionPass(StringRef Name, StringRef Flag)
+      : Pass(Name, Flag, ClassID::FunctionPass) {}
+  /// For isa/dyn_cast etc.
+  static bool classof(const Pass *From) {
+    switch (From->getSubclassID()) {
+    case ClassID::FunctionPass:
+      return true;
+    }
+  }
+  /// \Returns true if it modifies \p F.
+  virtual bool runOnFunction(Function &F) = 0;
+};
+
+} // namespace llvm::sandboxir
+
+#endif // LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASS_H

llvm/lib/SandboxIR/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_llvm_component_library(LLVMSandboxIR
+  Pass.cpp
   SandboxIR.cpp
   Tracker.cpp
   Type.cpp

llvm/lib/SandboxIR/Pass.cpp

@@ -0,0 +1,19 @@
+//===- Pass.cpp - Passes that operate on Sandbox IR -----------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/SandboxIR/Pass.h"
+#include "llvm/Support/Debug.h"
+
+using namespace llvm::sandboxir;
+
+#ifndef NDEBUG
+void Pass::dump() const {
+  dump(dbgs());
+  dbgs() << "\n";
+}
+#endif // NDEBUG

llvm/unittests/SandboxIR/CMakeLists.txt

@@ -5,6 +5,7 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_llvm_unittest(SandboxIRTests
+  PassTest.cpp
   SandboxIRTest.cpp
   TrackerTest.cpp
   TypesTest.cpp

llvm/unittests/SandboxIR/PassTest.cpp

@@ -0,0 +1,67 @@
+//===- PassesTest.cpp -----------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/SandboxIR/Pass.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Module.h"
+#include "llvm/SandboxIR/SandboxIR.h"
+#include "llvm/Support/SourceMgr.h"
+#include "gtest/gtest.h"
+
+using namespace llvm::sandboxir;
+
+struct PassTest : public testing::Test {
+  llvm::LLVMContext LLVMCtx;
+  std::unique_ptr<llvm::Module> LLVMM;
+  std::unique_ptr<Context> Ctx;
+
+  Function *parseFunction(const char *IR, const char *FuncName) {
+    llvm::SMDiagnostic Err;
+    LLVMM = parseAssemblyString(IR, Err, LLVMCtx);
+    if (!LLVMM)
+      Err.print("PassTest", llvm::errs());
+    Ctx = std::make_unique<Context>(LLVMCtx);
+    return Ctx->createFunction(LLVMM->getFunction(FuncName));
+  }
+};
+
+TEST_F(PassTest, FunctionPass) {
+  auto *F = parseFunction(R"IR(
+define void @foo() {
+  ret void
+}
+)IR",
+                          "foo");
+  class TestPass final : public FunctionPass {
+    unsigned &BBCnt;
+
+  public:
+    TestPass(unsigned &BBCnt)
+        : FunctionPass("TestPass", "-test-pass"), BBCnt(BBCnt) {}
+    bool runOnFunction(Function &F) final {
+      for ([[maybe_unused]] auto &BB : F)
+        ++BBCnt;
+      return false;
+    }
+  };
+  unsigned BBCnt = 0;
+  TestPass TPass(BBCnt);
+  // Check getName(),
+  EXPECT_EQ(TPass.getName(), "TestPass");
+  // Check getFlag().
+  EXPECT_EQ(TPass.getFlag(), "-test-pass");
+  // Check getSubclassID().
+  EXPECT_EQ(TPass.getSubclassID(), Pass::ClassID::FunctionPass);
+  // Check getSubclassIDStr().
+  EXPECT_EQ(Pass::getSubclassIDStr(TPass.getSubclassID()), "FunctionPass");
+  // Check classof().
+  EXPECT_TRUE(llvm::isa<FunctionPass>(TPass));
+  // Check runOnFunction();
+  TPass.runOnFunction(*F);
+  EXPECT_EQ(BBCnt, 1u);
+}