WebSVN – QNX 8.QNX8 LLVM/Clang compiler suite – Blame – //llvm-build/x86_64/include/llvm/Support/FileCollector.h

Rev	Author	Line No.	Line
14	pmbaty	1	//===-- FileCollector.h ------------------------------------------ C++ --===//
		2	//
		3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
		4	// See https://llvm.org/LICENSE.txt for license information.
		5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
		6	//
		7	//===----------------------------------------------------------------------===//
		8
		9	#ifndef LLVM_SUPPORT_FILECOLLECTOR_H
		10	#define LLVM_SUPPORT_FILECOLLECTOR_H
		11
		12	#include "llvm/ADT/StringMap.h"
		13	#include "llvm/ADT/StringSet.h"
		14	#include "llvm/Support/VirtualFileSystem.h"
		15	#include <mutex>
		16	#include <string>
		17
		18	namespace llvm {
		19	class FileCollectorFileSystem;
		20	class Twine;
		21
		22	class FileCollectorBase {
		23	public:
		24	FileCollectorBase();
		25	virtual ~FileCollectorBase();
		26
		27	void addFile(const Twine &file);
		28	void addDirectory(const Twine &Dir);
		29
		30	protected:
		31	bool markAsSeen(StringRef Path) {
		32	if (Path.empty())
		33	return false;
		34	return Seen.insert(Path).second;
		35	}
		36
		37	virtual void addFileImpl(StringRef SrcPath) = 0;
		38
		39	virtual llvm::vfs::directory_iterator
		40	addDirectoryImpl(const llvm::Twine &Dir,
		41	IntrusiveRefCntPtr<vfs::FileSystem> FS,
		42	std::error_code &EC) = 0;
		43
		44	/// Synchronizes access to internal data structures.
		45	std::mutex Mutex;
		46
		47	/// Tracks already seen files so they can be skipped.
		48	StringSet<> Seen;
		49	};
		50
		51	/// Captures file system interaction and generates data to be later replayed
		52	/// with the RedirectingFileSystem.
		53	///
		54	/// For any file that gets accessed we eventually create:
		55	/// - a copy of the file inside Root
		56	/// - a record in RedirectingFileSystem mapping that maps:
		57	/// current real path -> path to the copy in Root
		58	///
		59	/// That intent is that later when the mapping is used by RedirectingFileSystem
		60	/// it simulates the state of FS that we collected.
		61	///
		62	/// We generate file copies and mapping lazily - see writeMapping and copyFiles.
		63	/// We don't try to capture the state of the file at the exact time when it's
		64	/// accessed. Files might get changed, deleted ... we record only the "final"
		65	/// state.
		66	///
		67	/// In order to preserve the relative topology of files we use their real paths
		68	/// as relative paths inside of the Root.
		69	class FileCollector : public FileCollectorBase {
		70	public:
		71	/// Helper utility that encapsulates the logic for canonicalizing a virtual
		72	/// path and a path to copy from.
		73	class PathCanonicalizer {
		74	public:
		75	struct PathStorage {
		76	SmallString<256> CopyFrom;
		77	SmallString<256> VirtualPath;
		78	};
		79
		80	/// Canonicalize a pair of virtual and real paths.
		81	PathStorage canonicalize(StringRef SrcPath);
		82
		83	private:
		84	/// Replace with a (mostly) real path, or don't modify. Resolves symlinks
		85	/// in the directory, using \a CachedDirs to avoid redundant lookups, but
		86	/// leaves the filename as a possible symlink.
		87	void updateWithRealPath(SmallVectorImpl<char> &Path);
		88
		89	StringMap<std::string> CachedDirs;
		90	};
		91
		92	/// \p Root is the directory where collected files are will be stored.
		93	/// \p OverlayRoot is VFS mapping root.
		94	/// \p Root directory gets created in copyFiles unless it already exists.
		95	FileCollector(std::string Root, std::string OverlayRoot);
		96
		97	/// Write the yaml mapping (for the VFS) to the given file.
		98	std::error_code writeMapping(StringRef MappingFile);
		99
		100	/// Copy the files into the root directory.
		101	///
		102	/// When StopOnError is true (the default) we abort as soon as one file
		103	/// cannot be copied. This is relatively common, for example when a file was
		104	/// removed after it was added to the mapping.
		105	std::error_code copyFiles(bool StopOnError = true);
		106
		107	/// Create a VFS that uses \p Collector to collect files accessed via \p
		108	/// BaseFS.
		109	static IntrusiveRefCntPtr<vfs::FileSystem>
		110	createCollectorVFS(IntrusiveRefCntPtr<vfs::FileSystem> BaseFS,
		111	std::shared_ptr<FileCollector> Collector);
		112
		113	private:
		114	friend FileCollectorFileSystem;
		115
		116	void addFileToMapping(StringRef VirtualPath, StringRef RealPath) {
		117	if (sys::fs::is_directory(VirtualPath))
		118	VFSWriter.addDirectoryMapping(VirtualPath, RealPath);
		119	else
		120	VFSWriter.addFileMapping(VirtualPath, RealPath);
		121	}
		122
		123	protected:
		124	void addFileImpl(StringRef SrcPath) override;
		125
		126	llvm::vfs::directory_iterator
		127	addDirectoryImpl(const llvm::Twine &Dir,
		128	IntrusiveRefCntPtr<vfs::FileSystem> FS,
		129	std::error_code &EC) override;
		130
		131	/// The directory where collected files are copied to in copyFiles().
		132	const std::string Root;
		133
		134	/// The root directory where the VFS overlay lives.
		135	const std::string OverlayRoot;
		136
		137	/// The yaml mapping writer.
		138	vfs::YAMLVFSWriter VFSWriter;
		139
		140	/// Helper utility for canonicalizing paths.
		141	PathCanonicalizer Canonicalizer;
		142	};
		143
		144	} // end namespace llvm
		145
		146	#endif // LLVM_SUPPORT_FILECOLLECTOR_H

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QNX 8.QNX8 LLVM/Clang compiler suite//llvm-build/x86_64/include/llvm/Support/FileCollector.h – Rev 14