[Support] move FileCollector from LLDB to llvm/Support

The file collector class is useful for creating reproducers,
not just for LLDB, but for other tools as well in LLVM/Clang.

Differential Revision: https://reviews.llvm.org/D65237

llvm-svn: 366956
diff --git a/llvm/unittests/Support/FileCollectorTest.cpp b/llvm/unittests/Support/FileCollectorTest.cpp
new file mode 100644
index 0000000..38c5773
--- /dev/null
+++ b/llvm/unittests/Support/FileCollectorTest.cpp
@@ -0,0 +1,211 @@
+//===-- FileCollectorTest.cpp -----------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "llvm/Support/FileCollector.h"
+#include "llvm/Support/FileSystem.h"
+
+using namespace llvm;
+
+namespace llvm {
+namespace vfs {
+inline bool operator==(const llvm::vfs::YAMLVFSEntry &LHS,
+                       const llvm::vfs::YAMLVFSEntry &RHS) {
+  return LHS.VPath == RHS.VPath && LHS.RPath == RHS.RPath;
+}
+} // namespace vfs
+} // namespace llvm
+
+namespace {
+class TestingFileCollector : public FileCollector {
+public:
+  using FileCollector::FileCollector;
+  using FileCollector::m_root;
+  using FileCollector::m_seen;
+  using FileCollector::m_symlink_map;
+  using FileCollector::m_vfs_writer;
+
+  bool HasSeen(StringRef fs) {
+    return m_seen.find(fs) != m_seen.end();
+  }
+};
+
+struct ScopedDir {
+  SmallString<128> Path;
+  ScopedDir(const Twine &Name, bool Unique = false) {
+    std::error_code EC;
+    if (Unique) {
+      EC = llvm::sys::fs::createUniqueDirectory(Name, Path);
+    } else {
+      Path = Name.str();
+      EC = llvm::sys::fs::create_directory(Twine(Path));
+    }
+    if (EC)
+      Path = "";
+    EXPECT_FALSE(EC);
+    // Ensure the path is the real path so tests can use it to compare against
+    // realpath output.
+    SmallString<128> RealPath;
+    if (!llvm::sys::fs::real_path(Path, RealPath))
+      Path.swap(RealPath);
+  }
+  ~ScopedDir() {
+    if (Path != "") {
+      EXPECT_FALSE(llvm::sys::fs::remove_directories(Path.str()));
+    }
+  }
+  operator StringRef() { return Path.str(); }
+};
+
+struct ScopedLink {
+  SmallString<128> Path;
+  ScopedLink(const Twine &To, const Twine &From) {
+    Path = From.str();
+    std::error_code EC = sys::fs::create_link(To, From);
+    if (EC)
+      Path = "";
+    EXPECT_FALSE(EC);
+  }
+  ~ScopedLink() {
+    if (Path != "") {
+      EXPECT_FALSE(llvm::sys::fs::remove(Path.str()));
+    }
+  }
+  operator StringRef() { return Path.str(); }
+};
+
+struct ScopedFile {
+  SmallString<128> Path;
+  ScopedFile(const Twine &Name) {
+    std::error_code EC;
+    EC = llvm::sys::fs::createUniqueFile(Name, Path);
+    if (EC)
+      Path = "";
+    EXPECT_FALSE(EC);
+  }
+  ~ScopedFile() {
+    if (Path != "") {
+      EXPECT_FALSE(llvm::sys::fs::remove(Path.str()));
+    }
+  }
+  operator StringRef() { return Path.str(); }
+};
+} // end anonymous namespace
+
+TEST(FileCollectorTest, AddFile) {
+  ScopedDir root("add_file_root", true);
+  std::string root_fs = root.Path.str();
+  TestingFileCollector file_collector(root_fs, root_fs);
+
+  file_collector.AddFile("/path/to/a");
+  file_collector.AddFile("/path/to/b");
+  file_collector.AddFile("/path/to/c");
+
+  // Make sure the root is correct.
+  EXPECT_EQ(file_collector.m_root, root_fs);
+
+  // Make sure we've seen all the added files.
+  EXPECT_TRUE(file_collector.HasSeen("/path/to/a"));
+  EXPECT_TRUE(file_collector.HasSeen("/path/to/b"));
+  EXPECT_TRUE(file_collector.HasSeen("/path/to/c"));
+
+  // Make sure we've only seen the added files.
+  EXPECT_FALSE(file_collector.HasSeen("/path/to/d"));
+}
+
+TEST(FileCollectorTest, CopyFiles) {
+  ScopedDir file_root("file_root", true);
+  ScopedFile a(file_root + "/aaa");
+  ScopedFile b(file_root + "/bbb");
+  ScopedFile c(file_root + "/ccc");
+
+  // Create file collector and add files.
+  ScopedDir root("copy_files_root", true);
+  std::string root_fs = root.Path.str();
+  TestingFileCollector file_collector(root_fs, root_fs);
+  file_collector.AddFile(a.Path);
+  file_collector.AddFile(b.Path);
+  file_collector.AddFile(c.Path);
+
+  // Make sure we can copy the files.
+  std::error_code ec = file_collector.CopyFiles(true);
+  EXPECT_FALSE(ec);
+
+  // Now add a bogus file and make sure we error out.
+  file_collector.AddFile("/some/bogus/file");
+  ec = file_collector.CopyFiles(true);
+  EXPECT_TRUE(ec);
+
+  // However, if stop_on_error is true the copy should still succeed.
+  ec = file_collector.CopyFiles(false);
+  EXPECT_FALSE(ec);
+}
+
+#ifndef _WIN32
+TEST(FileCollectorTest, Symlinks) {
+  // Root where the original files live.
+  ScopedDir file_root("file_root", true);
+
+  // Create some files in the file root.
+  ScopedFile a(file_root + "/aaa");
+  ScopedFile b(file_root + "/bbb");
+  ScopedFile c(file_root + "/ccc");
+
+  // Create a directory foo with file ddd.
+  ScopedDir foo(file_root + "/foo");
+  ScopedFile d(foo + "/ddd");
+
+  // Create a file eee in the foo's parent directory.
+  ScopedFile e(foo + "/../eee");
+
+  // Create a symlink bar pointing to foo.
+  ScopedLink symlink(file_root + "/foo", file_root + "/bar");
+
+  // Root where files are copied to.
+  ScopedDir reproducer_root("reproducer_root", true);
+  std::string root_fs = reproducer_root.Path.str();
+  TestingFileCollector file_collector(root_fs, root_fs);
+
+  // Add all the files to the collector.
+  file_collector.AddFile(a.Path);
+  file_collector.AddFile(b.Path);
+  file_collector.AddFile(c.Path);
+  file_collector.AddFile(d.Path);
+  file_collector.AddFile(e.Path);
+  file_collector.AddFile(file_root + "/bar/ddd");
+
+  auto mapping = file_collector.m_vfs_writer.getMappings();
+
+  {
+    // Make sure the common case works.
+    std::string vpath = (file_root + "/aaa").str();
+    std::string rpath = (reproducer_root.Path + file_root.Path + "/aaa").str();
+    printf("%s -> %s\n", vpath.c_str(), rpath.c_str());
+    EXPECT_THAT(mapping, testing::Contains(vfs::YAMLVFSEntry(vpath, rpath)));
+  }
+
+  {
+    // Make sure the virtual path points to the real source path.
+    std::string vpath = (file_root + "/bar/ddd").str();
+    std::string rpath =
+        (reproducer_root.Path + file_root.Path + "/foo/ddd").str();
+    printf("%s -> %s\n", vpath.c_str(), rpath.c_str());
+    EXPECT_THAT(mapping, testing::Contains(vfs::YAMLVFSEntry(vpath, rpath)));
+  }
+
+  {
+    // Make sure that .. is removed from the source path.
+    std::string vpath = (file_root + "/eee").str();
+    std::string rpath = (reproducer_root.Path + file_root.Path + "/eee").str();
+    printf("%s -> %s\n", vpath.c_str(), rpath.c_str());
+    EXPECT_THAT(mapping, testing::Contains(vfs::YAMLVFSEntry(vpath, rpath)));
+  }
+}
+#endif