add clang tool to test dependency scanning

clang/tools/CMakeLists.txt

@@ -15,6 +15,7 @@ add_clang_subdirectory(clang-nvlink-wrapper)
 add_clang_subdirectory(clang-offload-packager)
 add_clang_subdirectory(clang-offload-bundler)
 add_clang_subdirectory(clang-scan-deps)
+add_clang_subdirectory(cpp-modules-from-driver)
 add_clang_subdirectory(clang-sycl-linker)
 add_clang_subdirectory(clang-installapi)
 if(HAVE_CLANG_REPL_SUPPORT)

clang/tools/cpp-modules-from-driver/CMakeLists.txt

@@ -0,0 +1,30 @@
+set(LLVM_LINK_COMPONENTS
+        ${LLVM_TARGETS_TO_BUILD}
+        Core
+        Option
+        Support
+        TargetParser
+)
+
+add_clang_tool(cpp-modules-from-driver
+        CPPModulesFromDriver.cpp
+
+        DEPENDS
+        GENERATE_DRIVER
+)
+
+set(CPP_MODULES_FROM_DRIVER_LIB_DEPS
+        clangAST
+        clangBasic
+        clangDependencyScanning
+        clangDriver
+        clangFrontend
+        clangLex
+        clangSerialization
+        clangTooling
+)
+
+clang_target_link_libraries(cpp-modules-from-driver
+        PRIVATE
+        ${CPP_MODULES_FROM_DRIVER_LIB_DEPS}
+)

clang/tools/cpp-modules-from-driver/CPPModulesFromDriver.cpp

@@ -0,0 +1,90 @@
+#include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
+#include "clang/Tooling/DependencyScanning/DependencyScanningWorker.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/LLVMDriver.h"
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+using namespace clang;
+using namespace clang::tooling;
+using namespace clang::tooling::dependencies;
+using namespace llvm;
+
+struct EnsureFinishedConsumer : public DiagnosticConsumer {
+  bool Finished = false;
+  void finish() override { Finished = true; }
+};
+
+int cpp_modules_from_driver_main(int argc, char **, const llvm::ToolContext &) {
+  StringRef CWD = "/root";
+
+  auto VFS = new llvm::vfs::InMemoryFileSystem();
+  VFS->setCurrentWorkingDirectory(CWD);
+  auto Sept = llvm::sys::path::get_separator();
+
+  std::vector<std::string> Files = {
+      std::string(llvm::formatv("{0}root{0}header.h", Sept)),
+      std::string(llvm::formatv("{0}root{0}test.cpp", Sept)),
+      std::string(llvm::formatv("{0}root{0}test.s", Sept)),
+      std::string(llvm::formatv("{0}root{0}module.cppm", Sept)),
+      std::string(llvm::formatv("{0}root{0}main.cpp", Sept))
+  };
+
+  VFS->addFile(Files[0], 0, llvm::MemoryBuffer::getMemBuffer("\n"));
+  VFS->addFile(Files[1], 0, llvm::MemoryBuffer::getMemBuffer("#include \"header.h\"\n"));
+  VFS->addFile(Files[2], 0, llvm::MemoryBuffer::getMemBuffer(""));
+  VFS->addFile(Files[3], 0, llvm::MemoryBuffer::getMemBuffer("export module M;\nexport int foo();\n"));
+  VFS->addFile(Files[4], 0, llvm::MemoryBuffer::getMemBuffer("#include \"header.h\"\nimport M;\nint main() { return foo(); }\n"));
+
+  DependencyScanningService Service(ScanningMode::DependencyDirectivesScan,
+                                    ScanningOutputFormat::Make);
+  DependencyScanningWorker Worker(Service, VFS);
+
+  for (const auto &File : Files) {
+
+    if (File == Files[2]) {
+      llvm::outs() << "Skipping assembly file: " << File << "\n";
+      continue;
+    }
+
+    llvm::DenseSet<ModuleID> AlreadySeen;
+    FullDependencyConsumer DC(AlreadySeen);
+    CallbackActionController AC(nullptr);
+
+    std::vector<std::string> Args = {
+        "clang++",
+        "-target",
+        "x86_64-unknown-linux-gnu",
+        "-c",
+        File,
+        "-o",
+        File + ".o"
+    };
+
+    EnsureFinishedConsumer DiagConsumer;
+    bool Success = Worker.computeDependencies(CWD, Args, DC, AC, DiagConsumer);
+
+    if (Success) {
+      TranslationUnitDeps TU = DC.takeTranslationUnitDeps();
+      llvm::outs() << "Dependencies for " << File << ":\n";
+      llvm::outs() << "  File Dependencies:\n";
+      for (const auto &FileDep : TU.FileDeps) {
+        llvm::outs() << "    - " << FileDep << "\n";
+      }
+      llvm::outs() << "  Module Dependencies:\n";
+      for (const auto &ModuleDep : TU.ClangModuleDeps) {
+        llvm::outs() << "[log] inside the Module Dependencies loop : ";
+        llvm::outs() << "    - " << "ModuleID{ModuleName: " << ModuleDep.ModuleName
+                     << ", ContextHash: " << ModuleDep.ContextHash << "}" << "\n";
+      }
+    } else {
+      llvm::errs() << "Failed to compute dependencies for " << File << ".\n";
+    }
+
+    llvm::outs() << "Success: " << Success << "\n";
+    llvm::outs() << "Diagnostic Consumer Finished: " << DiagConsumer.Finished << "\n";
+  }
+  return 0;
+}

llvm/utils/gn/secondary/clang/test/BUILD.gn

@@ -168,6 +168,7 @@ group("test") {
     "//clang/tools/clang-refactor",
     "//clang/tools/clang-repl",
     "//clang/tools/clang-scan-deps",
+    "//clang/tools/cpp-modules-from-driver",
     "//clang/tools/clang-sycl-linker",
     "//clang/tools/diagtool",
     "//clang/tools/driver:symlinks",