1 files changed, 222 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/contrib/llvm-project/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
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index 000000000000..32bbc578d2db
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+++ b/contrib/llvm-project/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -0,0 +1,222 @@
+//===- DependencyScanningWorker.cpp - clang-scan-deps worker --------------===//
+//
+// 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 "clang/Tooling/DependencyScanning/DependencyScanningWorker.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "clang/Tooling/DependencyScanning/DependencyScanningService.h"
+#include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
+#include "clang/Tooling/Tooling.h"
+
+using namespace clang;
+using namespace tooling;
+using namespace dependencies;
+
+namespace {
+
+/// Forwards the gatherered dependencies to the consumer.
+class DependencyConsumerForwarder : public DependencyFileGenerator {
+public:
+  DependencyConsumerForwarder(std::unique_ptr<DependencyOutputOptions> Opts,
+                              DependencyConsumer &C)
+      : DependencyFileGenerator(*Opts), Opts(std::move(Opts)), C(C) {}
+
+  void finishedMainFile(DiagnosticsEngine &Diags) override {
+    llvm::SmallString<256> CanonPath;
+    for (const auto &File : getDependencies()) {
+      CanonPath = File;
+      llvm::sys::path::remove_dots(CanonPath, /*remove_dot_dot=*/true);
+      C.handleFileDependency(*Opts, CanonPath);
+    }
+  }
+
+private:
+  std::unique_ptr<DependencyOutputOptions> Opts;
+  DependencyConsumer &C;
+};
+
+/// A proxy file system that doesn't call `chdir` when changing the working
+/// directory of a clang tool.
+class ProxyFileSystemWithoutChdir : public llvm::vfs::ProxyFileSystem {
+public:
+  ProxyFileSystemWithoutChdir(
+      llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS)
+      : ProxyFileSystem(std::move(FS)) {}
+
+  llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override {
+    assert(!CWD.empty() && "empty CWD");
+    return CWD;
+  }
+
+  std::error_code setCurrentWorkingDirectory(const Twine &Path) override {
+    CWD = Path.str();
+    return {};
+  }
+
+private:
+  std::string CWD;
+};
+
+/// A clang tool that runs the preprocessor in a mode that's optimized for
+/// dependency scanning for the given compiler invocation.
+class DependencyScanningAction : public tooling::ToolAction {
+public:
+  DependencyScanningAction(
+      StringRef WorkingDirectory, DependencyConsumer &Consumer,
+      llvm::IntrusiveRefCntPtr<DependencyScanningWorkerFilesystem> DepFS,
+      ExcludedPreprocessorDirectiveSkipMapping *PPSkipMappings,
+      ScanningOutputFormat Format)
+      : WorkingDirectory(WorkingDirectory), Consumer(Consumer),
+        DepFS(std::move(DepFS)), PPSkipMappings(PPSkipMappings),
+        Format(Format) {}
+
+  bool runInvocation(std::shared_ptr<CompilerInvocation> Invocation,
+                     FileManager *FileMgr,
+                     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
+                     DiagnosticConsumer *DiagConsumer) override {
+    // Create a compiler instance to handle the actual work.
+    CompilerInstance Compiler(std::move(PCHContainerOps));
+    Compiler.setInvocation(std::move(Invocation));
+
+    // Don't print 'X warnings and Y errors generated'.
+    Compiler.getDiagnosticOpts().ShowCarets = false;
+    // Create the compiler's actual diagnostics engine.
+    Compiler.createDiagnostics(DiagConsumer, /*ShouldOwnClient=*/false);
+    if (!Compiler.hasDiagnostics())
+      return false;
+
+    // Use the dependency scanning optimized file system if we can.
+    if (DepFS) {
+      const CompilerInvocation &CI = Compiler.getInvocation();
+      // Add any filenames that were explicity passed in the build settings and
+      // that might be opened, as we want to ensure we don't run source
+      // minimization on them.
+      DepFS->IgnoredFiles.clear();
+      for (const auto &Entry : CI.getHeaderSearchOpts().UserEntries)
+        DepFS->IgnoredFiles.insert(Entry.Path);
+      for (const auto &Entry : CI.getHeaderSearchOpts().VFSOverlayFiles)
+        DepFS->IgnoredFiles.insert(Entry);
+
+      // Support for virtual file system overlays on top of the caching
+      // filesystem.
+      FileMgr->setVirtualFileSystem(createVFSFromCompilerInvocation(
+          CI, Compiler.getDiagnostics(), DepFS));
+
+      // Pass the skip mappings which should speed up excluded conditional block
+      // skipping in the preprocessor.
+      if (PPSkipMappings)
+        Compiler.getPreprocessorOpts()
+            .ExcludedConditionalDirectiveSkipMappings = PPSkipMappings;
+    }
+
+    FileMgr->getFileSystemOpts().WorkingDir = std::string(WorkingDirectory);
+    Compiler.setFileManager(FileMgr);
+    Compiler.createSourceManager(*FileMgr);
+
+    // Create the dependency collector that will collect the produced
+    // dependencies.
+    //
+    // This also moves the existing dependency output options from the
+    // invocation to the collector. The options in the invocation are reset,
+    // which ensures that the compiler won't create new dependency collectors,
+    // and thus won't write out the extra '.d' files to disk.
+    auto Opts = std::make_unique<DependencyOutputOptions>(
+        std::move(Compiler.getInvocation().getDependencyOutputOpts()));
+    // We need at least one -MT equivalent for the generator to work.
+    if (Opts->Targets.empty())
+      Opts->Targets = {"clang-scan-deps dependency"};
+
+    switch (Format) {
+    case ScanningOutputFormat::Make:
+      Compiler.addDependencyCollector(
+          std::make_shared<DependencyConsumerForwarder>(std::move(Opts),
+                                                        Consumer));
+      break;
+    case ScanningOutputFormat::Full:
+      Compiler.addDependencyCollector(std::make_shared<ModuleDepCollector>(
+          std::move(Opts), Compiler, Consumer));
+      break;
+    }
+
+    // Consider different header search and diagnostic options to create
+    // different modules. This avoids the unsound aliasing of module PCMs.
+    //
+    // TODO: Implement diagnostic bucketing and header search pruning to reduce
+    // the impact of strict context hashing.
+    Compiler.getHeaderSearchOpts().ModulesStrictContextHash = true;
+
+    auto Action = std::make_unique<PreprocessOnlyAction>();
+    const bool Result = Compiler.ExecuteAction(*Action);
+    if (!DepFS)
+      FileMgr->clearStatCache();
+    return Result;
+  }
+
+private:
+  StringRef WorkingDirectory;
+  DependencyConsumer &Consumer;
+  llvm::IntrusiveRefCntPtr<DependencyScanningWorkerFilesystem> DepFS;
+  ExcludedPreprocessorDirectiveSkipMapping *PPSkipMappings;
+  ScanningOutputFormat Format;
+};
+
+} // end anonymous namespace
+
+DependencyScanningWorker::DependencyScanningWorker(
+    DependencyScanningService &Service)
+    : Format(Service.getFormat()) {
+  DiagOpts = new DiagnosticOptions();
+  PCHContainerOps = std::make_shared<PCHContainerOperations>();
+  RealFS = new ProxyFileSystemWithoutChdir(llvm::vfs::getRealFileSystem());
+  if (Service.canSkipExcludedPPRanges())
+    PPSkipMappings =
+        std::make_unique<ExcludedPreprocessorDirectiveSkipMapping>();
+  if (Service.getMode() == ScanningMode::MinimizedSourcePreprocessing)
+    DepFS = new DependencyScanningWorkerFilesystem(
+        Service.getSharedCache(), RealFS, PPSkipMappings.get());
+  if (Service.canReuseFileManager())
+    Files = new FileManager(FileSystemOptions(), RealFS);
+}
+
+static llvm::Error runWithDiags(
+    DiagnosticOptions *DiagOpts,
+    llvm::function_ref<bool(DiagnosticConsumer &DC)> BodyShouldSucceed) {
+  // Capture the emitted diagnostics and report them to the client
+  // in the case of a failure.
+  std::string DiagnosticOutput;
+  llvm::raw_string_ostream DiagnosticsOS(DiagnosticOutput);
+  TextDiagnosticPrinter DiagPrinter(DiagnosticsOS, DiagOpts);
+
+  if (BodyShouldSucceed(DiagPrinter))
+    return llvm::Error::success();
+  return llvm::make_error<llvm::StringError>(DiagnosticsOS.str(),
+                                             llvm::inconvertibleErrorCode());
+}
+
+llvm::Error DependencyScanningWorker::computeDependencies(
+    const std::string &Input, StringRef WorkingDirectory,
+    const CompilationDatabase &CDB, DependencyConsumer &Consumer) {
+  RealFS->setCurrentWorkingDirectory(WorkingDirectory);
+  return runWithDiags(DiagOpts.get(), [&](DiagnosticConsumer &DC) {
+    /// Create the tool that uses the underlying file system to ensure that any
+    /// file system requests that are made by the driver do not go through the
+    /// dependency scanning filesystem.
+    tooling::ClangTool Tool(CDB, Input, PCHContainerOps, RealFS, Files);
+    Tool.clearArgumentsAdjusters();
+    Tool.setRestoreWorkingDir(false);
+    Tool.setPrintErrorMessage(false);
+    Tool.setDiagnosticConsumer(&DC);
+    DependencyScanningAction Action(WorkingDirectory, Consumer, DepFS,
+                                    PPSkipMappings.get(), Format);
+    return !Tool.run(&Action);
+  });
+}