A virtual file system parsed from a YAML file. More...

#include "llvm/Support/VirtualFileSystem.h"

Inheritance diagram for llvm::vfs::RedirectingFileSystem:

Collaboration diagram for llvm::vfs::RedirectingFileSystem:

Classes
class	Entry
	A single file or directory in the VFS. More...

class	RedirectingDirectoryEntry

class	RedirectingFileEntry

Public Types
enum	EntryKind { EK_Directory, EK_File }

Public Member Functions
ErrorOr< Entry * >	lookupPath (const Twine &Path) const
	Looks up `Path` in `Roots`. More...

ErrorOr< Status >	status (const Twine &Path) override
	Get the status of the entry at `Path`, if one exists. More...

ErrorOr< std::unique_ptr< File > >	openFileForRead (const Twine &Path) override
	Get a `File` object for the file at `Path`, if one exists. More...

std::error_code	getRealPath (const Twine &Path, SmallVectorImpl< char > &Output) const override
	Gets real path of `Path` e.g. More...

llvm::ErrorOr< std::string >	getCurrentWorkingDirectory () const override
	Get the working directory of this file system. More...

std::error_code	setCurrentWorkingDirectory (const Twine &Path) override
	Set the working directory. More...

std::error_code	isLocal (const Twine &Path, bool &Result) override
	Is the file mounted on a local filesystem? More...

directory_iterator	dir_begin (const Twine &Dir, std::error_code &EC) override
	Get a directory_iterator for `Dir`. More...

void	setExternalContentsPrefixDir (StringRef PrefixDir)

StringRef	getExternalContentsPrefixDir () const

LLVM_DUMP_METHOD void	dump () const

LLVM_DUMP_METHOD void	dumpEntry (Entry *E, int NumSpaces=0) const

Public Member Functions inherited from llvm::vfs::FileSystem
virtual	~FileSystem ()

llvm::ErrorOr< std::unique_ptr< llvm::MemoryBuffer > >	getBufferForFile (const Twine &Name, int64_t FileSize=-1, bool RequiresNullTerminator=true, bool IsVolatile=false)
	This is a convenience method that opens a file, gets its content and then closes the file. More...

bool	exists (const Twine &Path)
	Check whether a file exists. Provided for convenience. More...

std::error_code	makeAbsolute (SmallVectorImpl< char > &Path) const
	Make Path an absolute path. More...

Public Member Functions inherited from llvm::ThreadSafeRefCountedBase< FileSystem >
void	Retain () const

void	Release () const

Static Public Member Functions
static RedirectingFileSystem *	create (std::unique_ptr< MemoryBuffer > Buffer, SourceMgr::DiagHandlerTy DiagHandler, StringRef YAMLFilePath, void *DiagContext, IntrusiveRefCntPtr< FileSystem > ExternalFS)
	Parses `Buffer`, which is expected to be in YAML format and returns a virtual file system representing its contents. More...

Friends
class	VFSFromYamlDirIterImpl

class	RedirectingFileSystemParser

Additional Inherited Members
Protected Member Functions inherited from llvm::ThreadSafeRefCountedBase< FileSystem >
	ThreadSafeRefCountedBase ()

Detailed Description

A virtual file system parsed from a YAML file.

Currently, this class allows creating virtual directories and mapping virtual file paths to existing external files, available in ExternalFS.

The basic structure of the parsed file is:

/// {
///   'version': <version number>,
///   <optional configuration>
///   'roots': [
///              <directory entries>
///            ]
/// }
///

All configuration options are optional.
  'case-sensitive': <boolean, default=true>
  'use-external-names': <boolean, default=true>
  'overlay-relative': <boolean, default=false>
  'fallthrough': <boolean, default=true>

Virtual directories are represented as

/// {
///   'type': 'directory',
///   'name': <string>,
///   'contents': [ <file or directory entries> ]
/// }
///

The default attributes for virtual directories are:

/// MTime = now() when created
/// Perms = 0777
/// User = Group = 0
/// Size = 0
/// UniqueID = unspecified unique value
///

Re-mapped files are represented as

/// {
///   'type': 'file',
///   'name': <string>,
///   'use-external-name': <boolean> # Optional
///   'external-contents': <path to external file>
/// }
///

and inherit their attributes from the external contents.

In both cases, the 'name' field may contain multiple path components (e.g.
/path/to/file). However, any directory that contains more than one child
must be uniquely represented by a directory entry.

Definition at line 557 of file VirtualFileSystem.h.

Member Enumeration Documentation

◆ EntryKind

enum llvm::vfs::RedirectingFileSystem::EntryKind

Enumerator
EK_Directory
EK_File

Definition at line 559 of file VirtualFileSystem.h.

Member Function Documentation

◆ create()

RedirectingFileSystem * RedirectingFileSystem::create	(	std::unique_ptr< MemoryBuffer >	Buffer,
		SourceMgr::DiagHandlerTy	DiagHandler,
		StringRef	YAMLFilePath,
		void *	DiagContext,
		IntrusiveRefCntPtr< FileSystem >	ExternalFS
	)

static

Parses Buffer, which is expected to be in YAML format and returns a virtual file system representing its contents.

Definition at line 1513 of file VirtualFileSystem.cpp.

References assert(), llvm::SourceMgr::DK_Error, llvm::StringRef::empty(), llvm::sys::fs::make_absolute(), P, llvm::sys::path::parent_path(), llvm::vfs::RedirectingFileSystemParser::parse(), llvm::SourceMgr::PrintMessage(), and llvm::SourceMgr::setDiagHandler().

Referenced by getRealPath(), and getVFSEntries().

◆ dir_begin()

directory_iterator RedirectingFileSystem::dir_begin	(	const Twine &	Dir,
		std::error_code &	EC
	)

overridevirtual

Get a directory_iterator for Dir.

Note: The 'end' iterator is directory_iterator().

Implements llvm::vfs::FileSystem.

Definition at line 1006 of file VirtualFileSystem.cpp.

References D, E, llvm::ErrorOr< T >::getError(), llvm::no_such_file_or_directory, llvm::not_a_directory, and llvm::vfs::InMemoryFileSystem::status().

◆ dump()

LLVM_DUMP_METHOD void RedirectingFileSystem::dump ( ) const

Definition at line 1041 of file VirtualFileSystem.cpp.

References LLVM_DUMP_METHOD.

◆ dumpEntry()

LLVM_DUMP_METHOD void RedirectingFileSystem::dumpEntry	(	RedirectingFileSystem::Entry *	E,
		int	NumSpaces = `0`
	)		const

Definition at line 1047 of file VirtualFileSystem.cpp.

References assert(), llvm::dbgs(), llvm::dyn_cast(), E, EK_Directory, llvm::vfs::RedirectingFileSystem::Entry::getKind(), llvm::vfs::RedirectingFileSystem::Entry::getName(), llvm::make_range(), and llvm::StringRef::str().

◆ getCurrentWorkingDirectory()

llvm::ErrorOr< std::string > RedirectingFileSystem::getCurrentWorkingDirectory ( ) const

overridevirtual

Get the working directory of this file system.

Implements llvm::vfs::FileSystem.

Definition at line 992 of file VirtualFileSystem.cpp.

◆ getExternalContentsPrefixDir()

StringRef RedirectingFileSystem::getExternalContentsPrefixDir ( ) const

Definition at line 1036 of file VirtualFileSystem.cpp.

◆ getRealPath()

std::error_code RedirectingFileSystem::getRealPath	(	const Twine &	Path,
		SmallVectorImpl< char > &	Output
	)		const

overridevirtual

Gets real path of Path e.g.

collapse all . and .. patterns, resolve symlinks. For real file system, this uses llvm::sys::fs::real_path. This returns errc::operation_not_permitted if not implemented by subclass.

Reimplemented from llvm::vfs::FileSystem.

Definition at line 1725 of file VirtualFileSystem.cpp.

References create(), F(), llvm::ErrorOr< T >::getError(), llvm::vfs::getVFSFromYAML(), llvm::invalid_argument, and llvm::no_such_file_or_directory.