[SandboxVec] Implement Pass class (llvm#107617)

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

llvm/include/llvm/SandboxIR/Pass.h

@@ -0,0 +1,55 @@
+//===- 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_SANDBOXIR_PASS_H
+#define LLVM_SANDBOXIR_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 {
+protected:
+  /// The pass name. This is also used as a command-line flag and should not
+  /// contain whitespaces.
+  const std::string Name;
+
+public:
+  Pass(StringRef Name) : Name(Name) {
+    assert(!Name.contains(' ') &&
+           "A pass name should not contain whitespaces!");
+    assert(!Name.starts_with('-') && "A pass name should not start with '-'!");
+  }
+  virtual ~Pass() {}
+  /// \Returns the name of the pass.
+  StringRef getName() const { return Name; }
+#ifndef NDEBUG
+  friend raw_ostream &operator<<(raw_ostream &OS, const Pass &Pass) {
+    Pass.print(OS);
+    return OS;
+  }
+  void print(raw_ostream &OS) const { OS << Name; }
+  LLVM_DUMP_METHOD void dump() const;
+#endif
+};
+
+/// A pass that runs on a sandbox::Function.
+class FunctionPass : public Pass {
+public:
+  FunctionPass(StringRef Name) : Pass(Name) {}
+  /// \Returns true if it modifies \p F.
+  virtual bool runOnFunction(Function &F) = 0;
+};
+
+} // namespace llvm::sandboxir
+
+#endif // LLVM_SANDBOXIR_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 {
+  print(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 +1,84 @@
+//===- PassTest.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("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(), "test-pass");
+  // Check classof().
+  EXPECT_TRUE(llvm::isa<FunctionPass>(TPass));
+  // Check runOnFunction();
+  TPass.runOnFunction(*F);
+  EXPECT_EQ(BBCnt, 1u);
+#ifndef NDEBUG
+  {
+    // Check print().
+    std::string Buff;
+    llvm::raw_string_ostream SS(Buff);
+    TPass.print(SS);
+    EXPECT_EQ(Buff, "test-pass");
+  }
+  {
+    // Check operator<<().
+    std::string Buff;
+    llvm::raw_string_ostream SS(Buff);
+    SS << TPass;
+    EXPECT_EQ(Buff, "test-pass");
+  }
+  // Check pass name assertions.
+  class TestNamePass final : public FunctionPass {
+  public:
+    TestNamePass(llvm::StringRef Name) : FunctionPass(Name) {}
+    bool runOnFunction(Function &F) { return false; }
+  };
+  EXPECT_DEATH(TestNamePass("white space"), ".*whitespace.*");
+  EXPECT_DEATH(TestNamePass("-dash"), ".*start with.*");
+#endif
+}