From 39ffea31df73b20d5549330d446713e56e60e801 Mon Sep 17 00:00:00 2001 From: Michael Woerister Date: Mon, 24 Apr 2017 19:01:19 +0200 Subject: [PATCH 1/5] Implement a file-path remapping feature in support of debuginfo and reproducible builds. --- src/grammar/verify.rs | 2 +- src/librustc/session/config.rs | 15 +- src/librustc/session/mod.rs | 29 +- src/librustc_driver/lib.rs | 2 +- src/librustc_driver/test.rs | 4 +- src/librustc_metadata/cstore_impl.rs | 2 +- src/librustc_metadata/decoder.rs | 4 +- src/librustc_metadata/encoder.rs | 32 ++- src/librustc_save_analysis/dump_visitor.rs | 2 + .../debuginfo/create_scope_map.rs | 23 +- src/librustc_trans/debuginfo/metadata.rs | 91 +++--- src/librustc_trans/debuginfo/mod.rs | 23 +- src/librustc_trans/debuginfo/namespace.rs | 2 +- src/librustc_trans/mir/mod.rs | 6 +- src/librustdoc/core.rs | 2 +- src/librustdoc/html/highlight.rs | 10 +- src/librustdoc/test.rs | 4 +- src/libsyntax/codemap.rs | 101 ++++--- src/libsyntax/ext/expand.rs | 2 +- src/libsyntax/ext/source_util.rs | 4 +- src/libsyntax/json.rs | 5 +- src/libsyntax/parse/lexer/comments.rs | 4 +- src/libsyntax/parse/lexer/mod.rs | 32 +-- src/libsyntax/parse/mod.rs | 16 +- src/libsyntax/test_snippet.rs | 6 +- src/libsyntax/util/parser_testing.rs | 15 +- src/libsyntax_pos/lib.rs | 13 +- src/test/codegen/remap_path_prefix.rs | 19 ++ src/test/compile-fail-fulldeps/qquote.rs | 3 +- src/test/run-fail-fulldeps/qquote.rs | 2 +- .../run-pass-fulldeps/ast_stmt_expr_attr.rs | 9 +- src/test/run-pass-fulldeps/qquote.rs | 3 +- src/tools/compiletest/src/header.rs | 271 ++++++++++-------- src/tools/compiletest/src/runtest.rs | 17 +- 34 files changed, 462 insertions(+), 313 deletions(-) create mode 100644 src/test/codegen/remap_path_prefix.rs diff --git a/src/grammar/verify.rs b/src/grammar/verify.rs index bd28a63c5f4df..3ac043f7aa9bc 100644 --- a/src/grammar/verify.rs +++ b/src/grammar/verify.rs @@ -296,7 +296,7 @@ fn main() { syntax::errors::registry::Registry::new(&[]), Rc::new(DummyCrateStore)); let filemap = session.parse_sess.codemap() - .new_filemap("".to_string(), None, code); + .new_filemap("".to_string(), code); let mut lexer = lexer::StringReader::new(session.diagnostic(), filemap); let cm = session.codemap(); diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index fadb1844008c0..888ed2a6d18df 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -25,6 +25,7 @@ use lint; use middle::cstore; use syntax::ast::{self, IntTy, UintTy}; +use syntax::codemap::FilePathMapping; use syntax::parse::token; use syntax::parse; use syntax::symbol::Symbol; @@ -492,6 +493,14 @@ impl Options { self.incremental.is_none() || self.cg.codegen_units == 1 } + + pub fn file_path_mapping(&self) -> FilePathMapping { + FilePathMapping::new( + self.debugging_opts.remap_path_prefix_from.iter().zip( + self.debugging_opts.remap_path_prefix_to.iter() + ).map(|(src, dst)| (src.clone(), dst.clone())).collect() + ) + } } // The type of entry function, so @@ -1012,6 +1021,10 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options, "Set the optimization fuel quota for a crate."), print_fuel: Option = (None, parse_opt_string, [TRACKED], "Make Rustc print the total optimization fuel used by a crate."), + remap_path_prefix_from: Vec = (vec![], parse_string_push, [TRACKED], + "add a source pattern to the file path remapping config"), + remap_path_prefix_to: Vec = (vec![], parse_string_push, [TRACKED], + "add a mapping target to the file path remapping config"), } pub fn default_lib_output() -> CrateType { @@ -1319,7 +1332,7 @@ pub fn rustc_optgroups() -> Vec { // Convert strings provided as --cfg [cfgspec] into a crate_cfg pub fn parse_cfgspecs(cfgspecs: Vec ) -> ast::CrateConfig { cfgspecs.into_iter().map(|s| { - let sess = parse::ParseSess::new(); + let sess = parse::ParseSess::new(FilePathMapping::empty()); let mut parser = parse::new_parser_from_source_str(&sess, "cfgspec".to_string(), s.to_string()); diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs index adc9aabb8c77a..c8732c31663eb 100644 --- a/src/librustc/session/mod.rs +++ b/src/librustc/session/mod.rs @@ -74,8 +74,10 @@ pub struct Session { // The name of the root source file of the crate, in the local file system. // The path is always expected to be absolute. `None` means that there is no // source file. - pub local_crate_source_file: Option, - pub working_dir: PathBuf, + pub local_crate_source_file: Option, + // The directory the compiler has been executed in plus a flag indicating + // if the value stored here has been affected by path remapping. + pub working_dir: (String, bool), pub lint_store: RefCell, pub lints: RefCell, /// Set of (LintId, span, message) tuples tracking lint (sub)diagnostics @@ -553,12 +555,14 @@ pub fn build_session(sopts: config::Options, registry: errors::registry::Registry, cstore: Rc) -> Session { + let file_path_mapping = sopts.file_path_mapping(); + build_session_with_codemap(sopts, dep_graph, local_crate_source_file, registry, cstore, - Rc::new(codemap::CodeMap::new()), + Rc::new(codemap::CodeMap::new(file_path_mapping)), None) } @@ -622,7 +626,7 @@ pub fn build_session_(sopts: config::Options, Ok(t) => t, Err(e) => { panic!(span_diagnostic.fatal(&format!("Error loading host specification: {}", e))); - } + } }; let target_cfg = config::build_target_config(&sopts, &span_diagnostic); let p_s = parse::ParseSess::with_span_handler(span_diagnostic, codemap); @@ -631,14 +635,12 @@ pub fn build_session_(sopts: config::Options, None => Some(filesearch::get_or_default_sysroot()) }; + let file_path_mapping = sopts.file_path_mapping(); + // Make the path absolute, if necessary - let local_crate_source_file = local_crate_source_file.map(|path| - if path.is_absolute() { - path.clone() - } else { - env::current_dir().unwrap().join(&path) - } - ); + let local_crate_source_file = local_crate_source_file.map(|path| { + file_path_mapping.map_prefix(path.to_string_lossy().into_owned()).0 + }); let optimization_fuel_crate = sopts.debugging_opts.fuel.as_ref().map(|i| i.0.clone()); let optimization_fuel_limit = Cell::new(sopts.debugging_opts.fuel.as_ref() @@ -646,6 +648,9 @@ pub fn build_session_(sopts: config::Options, let print_fuel_crate = sopts.debugging_opts.print_fuel.clone(); let print_fuel = Cell::new(0); + let working_dir = env::current_dir().unwrap().to_string_lossy().into_owned(); + let working_dir = file_path_mapping.map_prefix(working_dir); + let sess = Session { dep_graph: dep_graph.clone(), target: target_cfg, @@ -660,7 +665,7 @@ pub fn build_session_(sopts: config::Options, derive_registrar_fn: Cell::new(None), default_sysroot: default_sysroot, local_crate_source_file: local_crate_source_file, - working_dir: env::current_dir().unwrap(), + working_dir: working_dir, lint_store: RefCell::new(lint::LintStore::new()), lints: RefCell::new(lint::LintTable::new()), one_time_diagnostics: RefCell::new(FxHashSet()), diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs index 1a892b73aa5d7..e4ed2b8eb8fab 100644 --- a/src/librustc_driver/lib.rs +++ b/src/librustc_driver/lib.rs @@ -206,7 +206,7 @@ pub fn run_compiler<'a>(args: &[String], let cstore = Rc::new(CStore::new(&dep_graph)); let loader = file_loader.unwrap_or(box RealFileLoader); - let codemap = Rc::new(CodeMap::with_file_loader(loader)); + let codemap = Rc::new(CodeMap::with_file_loader(loader, sopts.file_path_mapping())); let mut sess = session::build_session_with_codemap( sopts, &dep_graph, input_file_path, descriptions, cstore.clone(), codemap, emitter_dest, ); diff --git a/src/librustc_driver/test.rs b/src/librustc_driver/test.rs index 147d6558e19cc..a19bc4aea2c9d 100644 --- a/src/librustc_driver/test.rs +++ b/src/librustc_driver/test.rs @@ -31,7 +31,7 @@ use rustc::session::{self, config}; use std::rc::Rc; use syntax::ast; use syntax::abi::Abi; -use syntax::codemap::CodeMap; +use syntax::codemap::{CodeMap, FilePathMapping}; use errors; use errors::emitter::Emitter; use errors::{Level, DiagnosticBuilder}; @@ -108,7 +108,7 @@ fn test_env(source_string: &str, &dep_graph, None, diagnostic_handler, - Rc::new(CodeMap::new()), + Rc::new(CodeMap::new(FilePathMapping::empty())), cstore.clone()); rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess)); let input = config::Input::Str { diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs index f310279ea3c3a..b7f571cfd2bc2 100644 --- a/src/librustc_metadata/cstore_impl.rs +++ b/src/librustc_metadata/cstore_impl.rs @@ -395,7 +395,7 @@ impl CrateStore for cstore::CStore { let (name, def) = data.get_macro(id.index); let source_name = format!("<{} macros>", name); - let filemap = sess.parse_sess.codemap().new_filemap(source_name, None, def.body); + let filemap = sess.parse_sess.codemap().new_filemap(source_name, def.body); let local_span = Span { lo: filemap.start_pos, hi: filemap.end_pos, ctxt: NO_EXPANSION }; let body = filemap_to_stream(&sess.parse_sess, filemap); diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs index 1656d489269d0..626dbf1a84fa8 100644 --- a/src/librustc_metadata/decoder.rs +++ b/src/librustc_metadata/decoder.rs @@ -1134,7 +1134,7 @@ impl<'a, 'tcx> CrateMetadata { // We can't reuse an existing FileMap, so allocate a new one // containing the information we need. let syntax_pos::FileMap { name, - abs_path, + name_was_remapped, start_pos, end_pos, lines, @@ -1158,7 +1158,7 @@ impl<'a, 'tcx> CrateMetadata { } let local_version = local_codemap.new_imported_filemap(name, - abs_path, + name_was_remapped, source_length, lines, multibyte_chars); diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs index 783e7604cdaf1..22b020439a46b 100644 --- a/src/librustc_metadata/encoder.rs +++ b/src/librustc_metadata/encoder.rs @@ -30,6 +30,7 @@ use std::hash::Hash; use std::intrinsics; use std::io::prelude::*; use std::io::Cursor; +use std::path::Path; use std::rc::Rc; use std::u32; use syntax::ast::{self, CRATE_NODE_ID}; @@ -1268,13 +1269,40 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> { fn encode_codemap(&mut self) -> LazySeq { let codemap = self.tcx.sess.codemap(); let all_filemaps = codemap.files.borrow(); - self.lazy_seq_ref(all_filemaps.iter() + let adapted = all_filemaps.iter() .filter(|filemap| { // No need to re-export imported filemaps, as any downstream // crate will import them from their original source. !filemap.is_imported() }) - .map(|filemap| &**filemap)) + .map(|filemap| { + // When exporting FileMaps, we expand all paths to absolute + // paths because any relative paths are potentially relative to + // a wrong directory. + // However, if a path has been modified via + // `-Zremap-path-prefix` we assume the user has already set + // things up the way they want and don't touch the path values + // anymore. + let name = Path::new(&filemap.name); + let (ref working_dir, working_dir_was_remapped) = self.tcx.sess.working_dir; + if filemap.name_was_remapped || + (name.is_relative() && working_dir_was_remapped) { + // This path of this FileMap has been modified by + // path-remapping, so we use it verbatim (and avoid cloning + // the whole map in the process). + filemap.clone() + } else { + let mut adapted = (**filemap).clone(); + let abs_path = Path::new(working_dir).join(name) + .to_string_lossy() + .into_owned(); + adapted.name = abs_path; + Rc::new(adapted) + } + }) + .collect::>(); + + self.lazy_seq_ref(adapted.iter().map(|fm| &**fm)) } fn encode_def_path_table(&mut self) -> Lazy { diff --git a/src/librustc_save_analysis/dump_visitor.rs b/src/librustc_save_analysis/dump_visitor.rs index 9e3e727d4bdcd..c84e0eba6aaf6 100644 --- a/src/librustc_save_analysis/dump_visitor.rs +++ b/src/librustc_save_analysis/dump_visitor.rs @@ -37,6 +37,7 @@ use rustc::ty::{self, TyCtxt, AssociatedItemContainer}; use std::collections::HashSet; use std::collections::hash_map::DefaultHasher; use std::hash::*; +use std::path::Path; use syntax::ast::{self, NodeId, PatKind, Attribute, CRATE_NODE_ID}; use syntax::parse::token; @@ -128,6 +129,7 @@ impl<'l, 'tcx: 'l, 'll, D: Dump + 'll> DumpVisitor<'l, 'tcx, 'll, D> { pub fn dump_crate_info(&mut self, name: &str, krate: &ast::Crate) { let source_file = self.tcx.sess.local_crate_source_file.as_ref(); let crate_root = source_file.map(|source_file| { + let source_file = Path::new(source_file); match source_file.file_name() { Some(_) => source_file.parent().unwrap().display().to_string(), None => source_file.display().to_string(), diff --git a/src/librustc_trans/debuginfo/create_scope_map.rs b/src/librustc_trans/debuginfo/create_scope_map.rs index 3d074c31c8a32..ae618c7e170df 100644 --- a/src/librustc_trans/debuginfo/create_scope_map.rs +++ b/src/librustc_trans/debuginfo/create_scope_map.rs @@ -8,12 +8,12 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use super::FunctionDebugContext; +use super::{FunctionDebugContext, FunctionDebugContextData}; use super::metadata::file_metadata; use super::utils::{DIB, span_start}; use llvm; -use llvm::debuginfo::{DIScope, DISubprogram}; +use llvm::debuginfo::DIScope; use common::CrateContext; use rustc::mir::{Mir, VisibilityScope}; @@ -53,8 +53,8 @@ pub fn create_mir_scopes(ccx: &CrateContext, mir: &Mir, debug_context: &Function }; let mut scopes = IndexVec::from_elem(null_scope, &mir.visibility_scopes); - let fn_metadata = match *debug_context { - FunctionDebugContext::RegularContext(ref data) => data.fn_metadata, + let debug_context = match *debug_context { + FunctionDebugContext::RegularContext(ref data) => data, FunctionDebugContext::DebugInfoDisabled | FunctionDebugContext::FunctionWithoutDebugInfo => { return scopes; @@ -71,7 +71,7 @@ pub fn create_mir_scopes(ccx: &CrateContext, mir: &Mir, debug_context: &Function // Instantiate all scopes. for idx in 0..mir.visibility_scopes.len() { let scope = VisibilityScope::new(idx); - make_mir_scope(ccx, &mir, &has_variables, fn_metadata, scope, &mut scopes); + make_mir_scope(ccx, &mir, &has_variables, debug_context, scope, &mut scopes); } scopes @@ -80,7 +80,7 @@ pub fn create_mir_scopes(ccx: &CrateContext, mir: &Mir, debug_context: &Function fn make_mir_scope(ccx: &CrateContext, mir: &Mir, has_variables: &BitVector, - fn_metadata: DISubprogram, + debug_context: &FunctionDebugContextData, scope: VisibilityScope, scopes: &mut IndexVec) { if scopes[scope].is_valid() { @@ -89,13 +89,13 @@ fn make_mir_scope(ccx: &CrateContext, let scope_data = &mir.visibility_scopes[scope]; let parent_scope = if let Some(parent) = scope_data.parent_scope { - make_mir_scope(ccx, mir, has_variables, fn_metadata, parent, scopes); + make_mir_scope(ccx, mir, has_variables, debug_context, parent, scopes); scopes[parent] } else { // The root is the function itself. let loc = span_start(ccx, mir.span); scopes[scope] = MirDebugScope { - scope_metadata: fn_metadata, + scope_metadata: debug_context.fn_metadata, file_start_pos: loc.file.start_pos, file_end_pos: loc.file.end_pos, }; @@ -109,14 +109,17 @@ fn make_mir_scope(ccx: &CrateContext, // However, we don't skip creating a nested scope if // our parent is the root, because we might want to // put arguments in the root and not have shadowing. - if parent_scope.scope_metadata != fn_metadata { + if parent_scope.scope_metadata != debug_context.fn_metadata { scopes[scope] = parent_scope; return; } } let loc = span_start(ccx, scope_data.span); - let file_metadata = file_metadata(ccx, &loc.file.name, &loc.file.abs_path); + let file_metadata = file_metadata(ccx, + &loc.file.name, + debug_context.defining_crate); + let scope_metadata = unsafe { llvm::LLVMRustDIBuilderCreateLexicalBlock( DIB(ccx), diff --git a/src/librustc_trans/debuginfo/metadata.rs b/src/librustc_trans/debuginfo/metadata.rs index 1f4756a94ea33..188f8ee336637 100644 --- a/src/librustc_trans/debuginfo/metadata.rs +++ b/src/librustc_trans/debuginfo/metadata.rs @@ -26,7 +26,7 @@ use llvm::debuginfo::{DIType, DIFile, DIScope, DIDescriptor, DICompositeType, DILexicalBlock, DIFlags}; use rustc::hir::def::CtorKind; -use rustc::hir::def_id::{DefId, LOCAL_CRATE}; +use rustc::hir::def_id::{DefId, CrateNum, LOCAL_CRATE}; use rustc::ty::fold::TypeVisitor; use rustc::ty::subst::Substs; use rustc::ty::util::TypeIdHasher; @@ -39,14 +39,12 @@ use rustc::ty::{self, AdtKind, Ty}; use rustc::ty::layout::{self, LayoutTyper}; use session::config; use util::nodemap::FxHashMap; -use util::common::path2cstr; use libc::{c_uint, c_longlong}; use std::ffi::CString; -use std::path::Path; use std::ptr; use syntax::ast; -use syntax::symbol::{Interner, InternedString}; +use syntax::symbol::{Interner, InternedString, Symbol}; use syntax_pos::{self, Span}; @@ -349,8 +347,7 @@ fn vec_slice_metadata<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, assert!(member_descriptions.len() == member_llvm_types.len()); - let loc = span_start(cx, span); - let file_metadata = file_metadata(cx, &loc.file.name, &loc.file.abs_path); + let file_metadata = unknown_file_metadata(cx); let metadata = composite_type_metadata(cx, slice_llvm_type, @@ -659,44 +656,51 @@ pub fn type_metadata<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, metadata } -pub fn file_metadata(cx: &CrateContext, path: &str, full_path: &Option) -> DIFile { - // FIXME (#9639): This needs to handle non-utf8 paths - let work_dir = cx.sess().working_dir.to_str().unwrap(); - let file_name = - full_path.as_ref().map(|p| p.as_str()).unwrap_or_else(|| { - if path.starts_with(work_dir) { - &path[work_dir.len() + 1..path.len()] - } else { - path - } - }); +pub fn file_metadata(cx: &CrateContext, + file_name: &str, + defining_crate: CrateNum) -> DIFile { + debug!("file_metadata: file_name: {}, defining_crate: {}", + file_name, + defining_crate); - file_metadata_(cx, path, file_name, &work_dir) + let directory = if defining_crate == LOCAL_CRATE { + &cx.sess().working_dir.0[..] + } else { + // If the path comes from an upstream crate we assume it has been made + // independent of the compiler's working directory one way or another. + "" + }; + + file_metadata_raw(cx, file_name, directory) } pub fn unknown_file_metadata(cx: &CrateContext) -> DIFile { - // Regular filenames should not be empty, so we abuse an empty name as the - // key for the special unknown file metadata - file_metadata_(cx, "", "", "") - + file_metadata_raw(cx, "", "") } -fn file_metadata_(cx: &CrateContext, key: &str, file_name: &str, work_dir: &str) -> DIFile { - if let Some(file_metadata) = debug_context(cx).created_files.borrow().get(key) { +fn file_metadata_raw(cx: &CrateContext, + file_name: &str, + directory: &str) + -> DIFile { + let key = (Symbol::intern(file_name), Symbol::intern(directory)); + + if let Some(file_metadata) = debug_context(cx).created_files.borrow().get(&key) { return *file_metadata; } - debug!("file_metadata: file_name: {}, work_dir: {}", file_name, work_dir); + debug!("file_metadata: file_name: {}, directory: {}", file_name, directory); let file_name = CString::new(file_name).unwrap(); - let work_dir = CString::new(work_dir).unwrap(); + let directory = CString::new(directory).unwrap(); + let file_metadata = unsafe { - llvm::LLVMRustDIBuilderCreateFile(DIB(cx), file_name.as_ptr(), - work_dir.as_ptr()) + llvm::LLVMRustDIBuilderCreateFile(DIB(cx), + file_name.as_ptr(), + directory.as_ptr()) }; let mut created_files = debug_context(cx).created_files.borrow_mut(); - created_files.insert(key.to_string(), file_metadata); + created_files.insert(key, file_metadata); file_metadata } @@ -761,25 +765,10 @@ pub fn compile_unit_metadata(scc: &SharedCrateContext, debug_context: &CrateDebugContext, sess: &Session) -> DIDescriptor { - let work_dir = &sess.working_dir; let compile_unit_name = match sess.local_crate_source_file { None => fallback_path(scc), - Some(ref abs_path) => { - if abs_path.is_relative() { - sess.warn("debuginfo: Invalid path to crate's local root source file!"); - fallback_path(scc) - } else { - match abs_path.strip_prefix(work_dir) { - Ok(ref p) if p.is_relative() => { - if p.starts_with(Path::new("./")) { - path2cstr(p) - } else { - path2cstr(&Path::new(".").join(p)) - } - } - _ => fallback_path(scc) - } - } + Some(ref path) => { + CString::new(&path[..]).unwrap() } }; @@ -789,7 +778,8 @@ pub fn compile_unit_metadata(scc: &SharedCrateContext, (option_env!("CFG_VERSION")).expect("CFG_VERSION")); let compile_unit_name = compile_unit_name.as_ptr(); - let work_dir = path2cstr(&work_dir); + + let work_dir = CString::new(&sess.working_dir.0[..]).unwrap(); let producer = CString::new(producer).unwrap(); let flags = "\0"; let split_name = "\0"; @@ -1760,7 +1750,7 @@ pub fn create_global_var_metadata(cx: &CrateContext, let (file_metadata, line_number) = if span != syntax_pos::DUMMY_SP { let loc = span_start(cx, span); - (file_metadata(cx, &loc.file.name, &loc.file.abs_path), loc.line as c_uint) + (file_metadata(cx, &loc.file.name, LOCAL_CRATE), loc.line as c_uint) } else { (unknown_file_metadata(cx), UNKNOWN_LINE_NUMBER) }; @@ -1795,9 +1785,10 @@ pub fn create_global_var_metadata(cx: &CrateContext, // Creates an "extension" of an existing DIScope into another file. pub fn extend_scope_to_file(ccx: &CrateContext, scope_metadata: DIScope, - file: &syntax_pos::FileMap) + file: &syntax_pos::FileMap, + defining_crate: CrateNum) -> DILexicalBlock { - let file_metadata = file_metadata(ccx, &file.name, &file.abs_path); + let file_metadata = file_metadata(ccx, &file.name, defining_crate); unsafe { llvm::LLVMRustDIBuilderCreateLexicalBlockFile( DIB(ccx), diff --git a/src/librustc_trans/debuginfo/mod.rs b/src/librustc_trans/debuginfo/mod.rs index 982ea5ffeb70b..ebe42a2b9082d 100644 --- a/src/librustc_trans/debuginfo/mod.rs +++ b/src/librustc_trans/debuginfo/mod.rs @@ -23,7 +23,7 @@ use self::source_loc::InternalDebugLocation::{self, UnknownLocation}; use llvm; use llvm::{ModuleRef, ContextRef, ValueRef}; use llvm::debuginfo::{DIFile, DIType, DIScope, DIBuilderRef, DISubprogram, DIArray, DIFlags}; -use rustc::hir::def_id::DefId; +use rustc::hir::def_id::{DefId, CrateNum}; use rustc::ty::subst::Substs; use abi::Abi; @@ -42,6 +42,7 @@ use std::ptr; use syntax_pos::{self, Span, Pos}; use syntax::ast; +use syntax::symbol::Symbol; use rustc::ty::layout; pub mod gdb; @@ -67,7 +68,7 @@ const DW_TAG_arg_variable: c_uint = 0x101; pub struct CrateDebugContext<'tcx> { llcontext: ContextRef, builder: DIBuilderRef, - created_files: RefCell>, + created_files: RefCell>, created_enum_disr_types: RefCell>, type_map: RefCell>, @@ -103,7 +104,7 @@ pub enum FunctionDebugContext { } impl FunctionDebugContext { - fn get_ref<'a>(&'a self, span: Span) -> &'a FunctionDebugContextData { + pub fn get_ref<'a>(&'a self, span: Span) -> &'a FunctionDebugContextData { match *self { FunctionDebugContext::RegularContext(ref data) => data, FunctionDebugContext::DebugInfoDisabled => { @@ -128,6 +129,7 @@ impl FunctionDebugContext { pub struct FunctionDebugContextData { fn_metadata: DISubprogram, source_locations_enabled: Cell, + pub defining_crate: CrateNum, } pub enum VariableAccess<'a> { @@ -220,8 +222,9 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, return FunctionDebugContext::FunctionWithoutDebugInfo; } + let def_id = instance.def_id(); let loc = span_start(cx, span); - let file_metadata = file_metadata(cx, &loc.file.name, &loc.file.abs_path); + let file_metadata = file_metadata(cx, &loc.file.name, def_id.krate); let function_type_metadata = unsafe { let fn_signature = get_function_signature(cx, sig); @@ -229,15 +232,15 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, }; // Find the enclosing function, in case this is a closure. - let def_key = cx.tcx().def_key(instance.def_id()); + let def_key = cx.tcx().def_key(def_id); let mut name = def_key.disambiguated_data.data.to_string(); let name_len = name.len(); - let fn_def_id = cx.tcx().closure_base_def_id(instance.def_id()); + let enclosing_fn_def_id = cx.tcx().closure_base_def_id(def_id); // Get_template_parameters() will append a `<...>` clause to the function // name if necessary. - let generics = cx.tcx().generics_of(fn_def_id); + let generics = cx.tcx().generics_of(enclosing_fn_def_id); let substs = instance.substs.truncate_to(cx.tcx(), generics); let template_parameters = get_template_parameters(cx, &generics, @@ -289,6 +292,7 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, let fn_debug_context = FunctionDebugContextData { fn_metadata: fn_metadata, source_locations_enabled: Cell::new(false), + defining_crate: def_id.krate, }; return FunctionDebugContext::RegularContext(fn_debug_context); @@ -438,8 +442,9 @@ pub fn declare_local<'a, 'tcx>(bcx: &Builder<'a, 'tcx>, let cx = bcx.ccx; let file = span_start(cx, span).file; - let filename = file.name.clone(); - let file_metadata = file_metadata(cx, &filename[..], &file.abs_path); + let file_metadata = file_metadata(cx, + &file.name[..], + dbg_context.get_ref(span).defining_crate); let loc = span_start(cx, span); let type_metadata = type_metadata(cx, variable_type, span); diff --git a/src/librustc_trans/debuginfo/namespace.rs b/src/librustc_trans/debuginfo/namespace.rs index 521dd7530beea..54a129536d03d 100644 --- a/src/librustc_trans/debuginfo/namespace.rs +++ b/src/librustc_trans/debuginfo/namespace.rs @@ -72,7 +72,7 @@ pub fn item_namespace(ccx: &CrateContext, def_id: DefId) -> DIScope { let span = ccx.tcx().def_span(def_id); let (file, line) = if span != DUMMY_SP { let loc = span_start(ccx, span); - (file_metadata(ccx, &loc.file.name, &loc.file.abs_path), loc.line as c_uint) + (file_metadata(ccx, &loc.file.name, def_id.krate), loc.line as c_uint) } else { (unknown_file_metadata(ccx), UNKNOWN_LINE_NUMBER) }; diff --git a/src/librustc_trans/mir/mod.rs b/src/librustc_trans/mir/mod.rs index af0e27c8ca391..19a556bf3f0f9 100644 --- a/src/librustc_trans/mir/mod.rs +++ b/src/librustc_trans/mir/mod.rs @@ -157,7 +157,11 @@ impl<'a, 'tcx> MirContext<'a, 'tcx> { if pos < self.scopes[scope_id].file_start_pos || pos >= self.scopes[scope_id].file_end_pos { let cm = self.ccx.sess().codemap(); - debuginfo::extend_scope_to_file(self.ccx, scope_metadata, &cm.lookup_char_pos(pos).file) + let defining_crate = self.debug_context.get_ref(DUMMY_SP).defining_crate; + debuginfo::extend_scope_to_file(self.ccx, + scope_metadata, + &cm.lookup_char_pos(pos).file, + defining_crate) } else { scope_metadata } diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs index a47d5f9937a02..6417270b9c73b 100644 --- a/src/librustdoc/core.rs +++ b/src/librustdoc/core.rs @@ -129,7 +129,7 @@ pub fn run_core(search_paths: SearchPaths, ..config::basic_options().clone() }; - let codemap = Rc::new(codemap::CodeMap::new()); + let codemap = Rc::new(codemap::CodeMap::new(sessopts.file_path_mapping())); let diagnostic_handler = errors::Handler::with_tty_emitter(ColorConfig::Auto, true, false, diff --git a/src/librustdoc/html/highlight.rs b/src/librustdoc/html/highlight.rs index 0dafc4225a321..15dada10c0dc1 100644 --- a/src/librustdoc/html/highlight.rs +++ b/src/librustdoc/html/highlight.rs @@ -26,7 +26,7 @@ use std::fmt::Display; use std::io; use std::io::prelude::*; -use syntax::codemap::CodeMap; +use syntax::codemap::{CodeMap, FilePathMapping}; use syntax::parse::lexer::{self, TokenAndSpan}; use syntax::parse::token; use syntax::parse; @@ -36,8 +36,8 @@ use syntax_pos::Span; pub fn render_with_highlighting(src: &str, class: Option<&str>, id: Option<&str>, extension: Option<&str>) -> String { debug!("highlighting: ================\n{}\n==============", src); - let sess = parse::ParseSess::new(); - let fm = sess.codemap().new_filemap("".to_string(), None, src.to_string()); + let sess = parse::ParseSess::new(FilePathMapping::empty()); + let fm = sess.codemap().new_filemap("".to_string(), src.to_string()); let mut out = Vec::new(); write_header(class, id, &mut out).unwrap(); @@ -58,8 +58,8 @@ pub fn render_with_highlighting(src: &str, class: Option<&str>, id: Option<&str> /// be inserted into an element. C.f., `render_with_highlighting` which includes /// an enclosing `
` block.
 pub fn render_inner_with_highlighting(src: &str) -> io::Result {
-    let sess = parse::ParseSess::new();
-    let fm = sess.codemap().new_filemap("".to_string(), None, src.to_string());
+    let sess = parse::ParseSess::new(FilePathMapping::empty());
+    let fm = sess.codemap().new_filemap("".to_string(), src.to_string());
 
     let mut out = Vec::new();
     let mut classifier = Classifier::new(lexer::StringReader::new(&sess, fm), sess.codemap());
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index 5b9ab304db0a9..5428b0663f368 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -74,7 +74,7 @@ pub fn run(input: &str,
         ..config::basic_options().clone()
     };
 
-    let codemap = Rc::new(CodeMap::new());
+    let codemap = Rc::new(CodeMap::new(sessopts.file_path_mapping()));
     let handler =
         errors::Handler::with_tty_emitter(ColorConfig::Auto, true, false, Some(codemap.clone()));
 
@@ -217,7 +217,7 @@ fn runtest(test: &str, cratename: &str, cfgs: Vec, libs: SearchPaths,
         }
     }
     let data = Arc::new(Mutex::new(Vec::new()));
-    let codemap = Rc::new(CodeMap::new());
+    let codemap = Rc::new(CodeMap::new(sessopts.file_path_mapping()));
     let emitter = errors::emitter::EmitterWriter::new(box Sink(data.clone()),
                                                       Some(codemap.clone()));
     let old = io::set_panic(Some(box Sink(data.clone())));
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index da2d0a33d1a10..8a88ec3a6724f 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -104,32 +104,42 @@ impl FileLoader for RealFileLoader {
 
 pub struct CodeMap {
     pub files: RefCell>>,
-    file_loader: Box
+    file_loader: Box,
+    // This is used to apply the file path remapping as specified via
+    // -Zremap-path-prefix to all FileMaps allocated within this CodeMap.
+    path_mapping: FilePathMapping,
 }
 
 impl CodeMap {
-    pub fn new() -> CodeMap {
+    pub fn new(path_mapping: FilePathMapping) -> CodeMap {
         CodeMap {
             files: RefCell::new(Vec::new()),
-            file_loader: Box::new(RealFileLoader)
+            file_loader: Box::new(RealFileLoader),
+            path_mapping: path_mapping,
         }
     }
 
-    pub fn with_file_loader(file_loader: Box) -> CodeMap {
+    pub fn with_file_loader(file_loader: Box,
+                            path_mapping: FilePathMapping)
+                            -> CodeMap {
         CodeMap {
             files: RefCell::new(Vec::new()),
-            file_loader: file_loader
+            file_loader: file_loader,
+            path_mapping: path_mapping,
         }
     }
 
+    pub fn path_mapping(&self) -> &FilePathMapping {
+        &self.path_mapping
+    }
+
     pub fn file_exists(&self, path: &Path) -> bool {
         self.file_loader.file_exists(path)
     }
 
     pub fn load_file(&self, path: &Path) -> io::Result> {
         let src = self.file_loader.read_file(path)?;
-        let abs_path = self.file_loader.abs_path(path).map(|p| p.to_str().unwrap().to_string());
-        Ok(self.new_filemap(path.to_str().unwrap().to_string(), abs_path, src))
+        Ok(self.new_filemap(path.to_str().unwrap().to_string(), src))
     }
 
     fn next_start_pos(&self) -> usize {
@@ -144,8 +154,7 @@ impl CodeMap {
 
     /// Creates a new filemap without setting its line information. If you don't
     /// intend to set the line information yourself, you should use new_filemap_and_lines.
-    pub fn new_filemap(&self, filename: FileName, abs_path: Option,
-                       mut src: String) -> Rc {
+    pub fn new_filemap(&self, filename: FileName, mut src: String) -> Rc {
         let start_pos = self.next_start_pos();
         let mut files = self.files.borrow_mut();
 
@@ -156,9 +165,11 @@ impl CodeMap {
 
         let end_pos = start_pos + src.len();
 
+        let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
+
         let filemap = Rc::new(FileMap {
             name: filename,
-            abs_path: abs_path,
+            name_was_remapped: was_remapped,
             src: Some(Rc::new(src)),
             start_pos: Pos::from_usize(start_pos),
             end_pos: Pos::from_usize(end_pos),
@@ -172,11 +183,8 @@ impl CodeMap {
     }
 
     /// Creates a new filemap and sets its line information.
-    pub fn new_filemap_and_lines(&self, filename: &str, abs_path: Option<&str>,
-                                 src: &str) -> Rc {
-        let fm = self.new_filemap(filename.to_string(),
-                                  abs_path.map(|s| s.to_owned()),
-                                  src.to_owned());
+    pub fn new_filemap_and_lines(&self, filename: &str, src: &str) -> Rc {
+        let fm = self.new_filemap(filename.to_string(), src.to_owned());
         let mut byte_pos: u32 = fm.start_pos.0;
         for line in src.lines() {
             // register the start of this line
@@ -195,7 +203,7 @@ impl CodeMap {
     /// information for things inlined from other crates.
     pub fn new_imported_filemap(&self,
                                 filename: FileName,
-                                abs_path: Option,
+                                name_was_remapped: bool,
                                 source_len: usize,
                                 mut file_local_lines: Vec,
                                 mut file_local_multibyte_chars: Vec)
@@ -216,7 +224,7 @@ impl CodeMap {
 
         let filemap = Rc::new(FileMap {
             name: filename,
-            abs_path: abs_path,
+            name_was_remapped: name_was_remapped,
             src: None,
             start_pos: start_pos,
             end_pos: end_pos,
@@ -550,6 +558,42 @@ impl CodeMapper for CodeMap {
     }
 }
 
+#[derive(Clone)]
+pub struct FilePathMapping {
+    mapping: Vec<(String, String)>,
+}
+
+impl FilePathMapping {
+    pub fn empty() -> FilePathMapping {
+        FilePathMapping {
+            mapping: vec![]
+        }
+    }
+
+    pub fn new(mapping: Vec<(String, String)>) -> FilePathMapping {
+        FilePathMapping {
+            mapping: mapping
+        }
+    }
+
+    /// Applies any path prefix substitution as defined by the mapping.
+    /// The return value is the remapped path and a boolean indicating whether
+    /// the path was affected by the mapping.
+    pub fn map_prefix(&self, path: String) -> (String, bool) {
+        // NOTE: We are iterating over the mapping entries from last to first
+        //       because entries specified later on the command line should
+        //       take precedence.
+        for &(ref from, ref to) in self.mapping.iter().rev() {
+            if path.starts_with(from) {
+                let mapped = path.replacen(from, to, 1);
+                return (mapped, true);
+            }
+        }
+
+        (path, false)
+    }
+}
+
 // _____________________________________________________________________________
 // Tests
 //
@@ -561,9 +605,8 @@ mod tests {
 
     #[test]
     fn t1 () {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm = cm.new_filemap("blork.rs".to_string(),
-                                None,
                                 "first line.\nsecond line".to_string());
         fm.next_line(BytePos(0));
         // Test we can get lines with partial line info.
@@ -578,9 +621,8 @@ mod tests {
     #[test]
     #[should_panic]
     fn t2 () {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm = cm.new_filemap("blork.rs".to_string(),
-                                None,
                                 "first line.\nsecond line".to_string());
         // TESTING *REALLY* BROKEN BEHAVIOR:
         fm.next_line(BytePos(0));
@@ -589,15 +631,12 @@ mod tests {
     }
 
     fn init_code_map() -> CodeMap {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm1 = cm.new_filemap("blork.rs".to_string(),
-                                 None,
                                  "first line.\nsecond line".to_string());
         let fm2 = cm.new_filemap("empty.rs".to_string(),
-                                 None,
                                  "".to_string());
         let fm3 = cm.new_filemap("blork2.rs".to_string(),
-                                 None,
                                  "first line.\nsecond line".to_string());
 
         fm1.next_line(BytePos(0));
@@ -656,14 +695,12 @@ mod tests {
     }
 
     fn init_code_map_mbc() -> CodeMap {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         // € is a three byte utf8 char.
         let fm1 =
             cm.new_filemap("blork.rs".to_string(),
-                           None,
                            "fir€st €€€€ line.\nsecond line".to_string());
         let fm2 = cm.new_filemap("blork2.rs".to_string(),
-                                 None,
                                  "first line€€.\n€ second line".to_string());
 
         fm1.next_line(BytePos(0));
@@ -728,10 +765,10 @@ mod tests {
     /// lines in the middle of a file.
     #[test]
     fn span_to_snippet_and_lines_spanning_multiple_lines() {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
         let selection = "     \n    ~~\n~~~\n~~~~~     \n   \n";
-        cm.new_filemap_and_lines("blork.rs", None, inputtext);
+        cm.new_filemap_and_lines("blork.rs", inputtext);
         let span = span_from_selection(inputtext, selection);
 
         // check that we are extracting the text we thought we were extracting
@@ -770,11 +807,11 @@ mod tests {
     /// Test failing to merge two spans on different lines
     #[test]
     fn span_merging_fail() {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let inputtext  = "bbbb BB\ncc CCC\n";
         let selection1 = "     ~~\n      \n";
         let selection2 = "       \n   ~~~\n";
-        cm.new_filemap_and_lines("blork.rs", None, inputtext);
+        cm.new_filemap_and_lines("blork.rs", inputtext);
         let span1 = span_from_selection(inputtext, selection1);
         let span2 = span_from_selection(inputtext, selection2);
 
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 842398ea02b9e..2db295d013639 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -783,7 +783,7 @@ fn stream_for_item(item: &Annotatable, parse_sess: &ParseSess) -> TokenStream {
 
 fn string_to_stream(text: String, parse_sess: &ParseSess) -> TokenStream {
     let filename = String::from("");
-    filemap_to_stream(parse_sess, parse_sess.codemap().new_filemap(filename, None, text))
+    filemap_to_stream(parse_sess, parse_sess.codemap().new_filemap(filename, text))
 }
 
 impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 0103d6ea959dd..22a5776315a0c 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -142,7 +142,7 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenT
             // Add this input file to the code map to make it available as
             // dependency information
             let filename = format!("{}", file.display());
-            cx.codemap().new_filemap_and_lines(&filename, None, &src);
+            cx.codemap().new_filemap_and_lines(&filename, &src);
 
             base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&src)))
         }
@@ -173,7 +173,7 @@ pub fn expand_include_bytes(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::Toke
             // Add this input file to the code map to make it available as
             // dependency information, but don't enter it's contents
             let filename = format!("{}", file.display());
-            cx.codemap().new_filemap_and_lines(&filename, None, "");
+            cx.codemap().new_filemap_and_lines(&filename, "");
 
             base::MacEager::expr(cx.expr_lit(sp, ast::LitKind::ByteStr(Rc::new(bytes))))
         }
diff --git a/src/libsyntax/json.rs b/src/libsyntax/json.rs
index dec1b7d1d87be..47b60f0e080d0 100644
--- a/src/libsyntax/json.rs
+++ b/src/libsyntax/json.rs
@@ -19,7 +19,7 @@
 
 // FIXME spec the JSON output properly.
 
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use syntax_pos::{self, MacroBacktrace, Span, SpanLabel, MultiSpan};
 use errors::registry::Registry;
 use errors::{DiagnosticBuilder, SubDiagnostic, RenderSpan, CodeSuggestion, CodeMapper};
@@ -48,7 +48,8 @@ impl JsonEmitter {
     }
 
     pub fn basic() -> JsonEmitter {
-        JsonEmitter::stderr(None, Rc::new(CodeMap::new()))
+        let file_path_mapping = FilePathMapping::empty();
+        JsonEmitter::stderr(None, Rc::new(CodeMap::new(file_path_mapping)))
     }
 
     pub fn new(dst: Box,
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index c97b8ddf91972..7ac322b144c7e 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -348,8 +348,8 @@ pub fn gather_comments_and_literals(sess: &ParseSess, path: String, srdr: &mut R
     let mut src = Vec::new();
     srdr.read_to_end(&mut src).unwrap();
     let src = String::from_utf8(src).unwrap();
-    let cm = CodeMap::new();
-    let filemap = cm.new_filemap(path, None, src);
+    let cm = CodeMap::new(sess.codemap().path_mapping().clone());
+    let filemap = cm.new_filemap(path, src);
     let mut rdr = lexer::StringReader::new_raw(sess, filemap);
 
     let mut comments: Vec = Vec::new();
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 920b2c401e2bd..c2e5763237d3c 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -10,7 +10,7 @@
 
 use ast::{self, Ident};
 use syntax_pos::{self, BytePos, CharPos, Pos, Span, NO_EXPANSION};
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use errors::{FatalError, DiagnosticBuilder};
 use parse::{token, ParseSess};
 use str::char_at;
@@ -563,7 +563,7 @@ impl<'a> StringReader<'a> {
 
                 // I guess this is the only way to figure out if
                 // we're at the beginning of the file...
-                let cmap = CodeMap::new();
+                let cmap = CodeMap::new(FilePathMapping::empty());
                 cmap.files.borrow_mut().push(self.filemap.clone());
                 let loc = cmap.lookup_char_pos_adj(self.pos);
                 debug!("Skipping a shebang");
@@ -1718,13 +1718,13 @@ mod tests {
                  sess: &'a ParseSess,
                  teststr: String)
                  -> StringReader<'a> {
-        let fm = cm.new_filemap("zebra.rs".to_string(), None, teststr);
+        let fm = cm.new_filemap("zebra.rs".to_string(), teststr);
         StringReader::new(sess, fm)
     }
 
     #[test]
     fn t1() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut string_reader = setup(&cm,
                                       &sh,
@@ -1776,7 +1776,7 @@ mod tests {
 
     #[test]
     fn doublecolonparsing() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a b".to_string()),
                            vec![mk_ident("a"), token::Whitespace, mk_ident("b")]);
@@ -1784,7 +1784,7 @@ mod tests {
 
     #[test]
     fn dcparsing_2() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a::b".to_string()),
                            vec![mk_ident("a"), token::ModSep, mk_ident("b")]);
@@ -1792,7 +1792,7 @@ mod tests {
 
     #[test]
     fn dcparsing_3() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a ::b".to_string()),
                            vec![mk_ident("a"), token::Whitespace, token::ModSep, mk_ident("b")]);
@@ -1800,7 +1800,7 @@ mod tests {
 
     #[test]
     fn dcparsing_4() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a:: b".to_string()),
                            vec![mk_ident("a"), token::ModSep, token::Whitespace, mk_ident("b")]);
@@ -1808,7 +1808,7 @@ mod tests {
 
     #[test]
     fn character_a() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'a'".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern("a")), None));
@@ -1816,7 +1816,7 @@ mod tests {
 
     #[test]
     fn character_space() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "' '".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern(" ")), None));
@@ -1824,7 +1824,7 @@ mod tests {
 
     #[test]
     fn character_escaped() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'\\n'".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern("\\n")), None));
@@ -1832,7 +1832,7 @@ mod tests {
 
     #[test]
     fn lifetime_name() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'abc".to_string()).next_token().tok,
                    token::Lifetime(Ident::from_str("'abc")));
@@ -1840,7 +1840,7 @@ mod tests {
 
     #[test]
     fn raw_string() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "r###\"\"#a\\b\x00c\"\"###".to_string())
                        .next_token()
@@ -1850,7 +1850,7 @@ mod tests {
 
     #[test]
     fn literal_suffixes() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         macro_rules! test {
             ($input: expr, $tok_type: ident, $tok_contents: expr) => {{
@@ -1894,7 +1894,7 @@ mod tests {
 
     #[test]
     fn nested_block_comments() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut lexer = setup(&cm, &sh, "/* /* */ */'a'".to_string());
         match lexer.next_token().tok {
@@ -1907,7 +1907,7 @@ mod tests {
 
     #[test]
     fn crlf_comments() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut lexer = setup(&cm, &sh, "// test\r\n/// test\r\n".to_string());
         let comment = lexer.next_token();
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index c63a6524f7459..9d8f3b3d039d2 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -11,7 +11,7 @@
 //! The main parser interface
 
 use ast::{self, CrateConfig};
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use syntax_pos::{self, Span, FileMap, NO_EXPANSION};
 use errors::{Handler, ColorConfig, DiagnosticBuilder};
 use feature_gate::UnstableFeatures;
@@ -53,8 +53,8 @@ pub struct ParseSess {
 }
 
 impl ParseSess {
-    pub fn new() -> Self {
-        let cm = Rc::new(CodeMap::new());
+    pub fn new(file_path_mapping: FilePathMapping) -> Self {
+        let cm = Rc::new(CodeMap::new(file_path_mapping));
         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
                                                 true,
                                                 false,
@@ -143,13 +143,13 @@ pub fn parse_stmt_from_source_str<'a>(name: String, source: String, sess: &'a Pa
 
 pub fn parse_stream_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
                                         -> TokenStream {
-    filemap_to_stream(sess, sess.codemap().new_filemap(name, None, source))
+    filemap_to_stream(sess, sess.codemap().new_filemap(name, source))
 }
 
 // Create a new parser from a source string
 pub fn new_parser_from_source_str<'a>(sess: &'a ParseSess, name: String, source: String)
                                       -> Parser<'a> {
-    filemap_to_parser(sess, sess.codemap().new_filemap(name, None, source))
+    filemap_to_parser(sess, sess.codemap().new_filemap(name, source))
 }
 
 /// Create a new parser, handling errors as appropriate
@@ -828,7 +828,7 @@ mod tests {
     }
 
     #[test] fn parse_ident_pat () {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
         let mut parser = string_to_parser(&sess, "b".to_string());
         assert!(panictry!(parser.parse_pat())
                 == P(ast::Pat{
@@ -998,7 +998,7 @@ mod tests {
     }
 
     #[test] fn crlf_doc_comments() {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
 
         let name = "".to_string();
         let source = "/// doc comment\r\nfn foo() {}".to_string();
@@ -1023,7 +1023,7 @@ mod tests {
 
     #[test]
     fn ttdelim_span() {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
         let expr = parse::parse_expr_from_source_str("foo".to_string(),
             "foo!( fn main() { body } )".to_string(), &sess).unwrap();
 
diff --git a/src/libsyntax/test_snippet.rs b/src/libsyntax/test_snippet.rs
index dc9b22c37e28b..b3fa1e97376d0 100644
--- a/src/libsyntax/test_snippet.rs
+++ b/src/libsyntax/test_snippet.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use errors::Handler;
 use errors::emitter::EmitterWriter;
 use std::io;
@@ -47,8 +47,8 @@ impl Write for Shared {
 fn test_harness(file_text: &str, span_labels: Vec, expected_output: &str) {
     let output = Arc::new(Mutex::new(Vec::new()));
 
-    let code_map = Rc::new(CodeMap::new());
-    code_map.new_filemap_and_lines("test.rs", None, &file_text);
+    let code_map = Rc::new(CodeMap::new(FilePathMapping::empty()));
+    code_map.new_filemap_and_lines("test.rs", &file_text);
 
     let primary_span = make_span(&file_text, &span_labels[0].start, &span_labels[0].end);
     let mut msp = MultiSpan::from_span(primary_span);
diff --git a/src/libsyntax/util/parser_testing.rs b/src/libsyntax/util/parser_testing.rs
index 51eb295b502a7..2727ab79ebf76 100644
--- a/src/libsyntax/util/parser_testing.rs
+++ b/src/libsyntax/util/parser_testing.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 use ast::{self, Ident};
+use codemap::FilePathMapping;
 use parse::{ParseSess, PResult, filemap_to_stream};
 use parse::{lexer, new_parser_from_source_str};
 use parse::parser::Parser;
@@ -18,8 +19,8 @@ use std::iter::Peekable;
 
 /// Map a string to tts, using a made-up filename:
 pub fn string_to_stream(source_str: String) -> TokenStream {
-    let ps = ParseSess::new();
-    filemap_to_stream(&ps, ps.codemap().new_filemap("bogofile".to_string(), None, source_str))
+    let ps = ParseSess::new(FilePathMapping::empty());
+    filemap_to_stream(&ps, ps.codemap().new_filemap("bogofile".to_string(), source_str))
 }
 
 /// Map string to parser (via tts)
@@ -38,7 +39,7 @@ fn with_error_checking_parse<'a, T, F>(s: String, ps: &'a ParseSess, f: F) -> T
 
 /// Parse a string, return a crate.
 pub fn string_to_crate (source_str : String) -> ast::Crate {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_crate_mod()
     })
@@ -46,7 +47,7 @@ pub fn string_to_crate (source_str : String) -> ast::Crate {
 
 /// Parse a string, return an expr
 pub fn string_to_expr (source_str : String) -> P {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_expr()
     })
@@ -54,7 +55,7 @@ pub fn string_to_expr (source_str : String) -> P {
 
 /// Parse a string, return an item
 pub fn string_to_item (source_str : String) -> Option> {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_item()
     })
@@ -62,7 +63,7 @@ pub fn string_to_item (source_str : String) -> Option> {
 
 /// Parse a string, return a stmt
 pub fn string_to_stmt(source_str : String) -> Option {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_stmt()
     })
@@ -71,7 +72,7 @@ pub fn string_to_stmt(source_str : String) -> Option {
 /// Parse a string, return a pat. Uses "irrefutable"... which doesn't
 /// (currently) affect parsing.
 pub fn string_to_pat(source_str: String) -> P {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_pat()
     })
diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index aaafcadc38a14..f46b4fcb715b0 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -369,13 +369,14 @@ pub struct MultiByteChar {
 }
 
 /// A single source in the CodeMap.
+#[derive(Clone)]
 pub struct FileMap {
     /// The name of the file that the source came from, source that doesn't
     /// originate from files has names between angle brackets by convention,
     /// e.g. ``
     pub name: FileName,
-    /// The absolute path of the file that the source came from.
-    pub abs_path: Option,
+    /// True if the `name` field above has been modified by -Zremap-path-prefix
+    pub name_was_remapped: bool,
     /// The complete source code
     pub src: Option>,
     /// The start position of this source in the CodeMap
@@ -392,7 +393,7 @@ impl Encodable for FileMap {
     fn encode(&self, s: &mut S) -> Result<(), S::Error> {
         s.emit_struct("FileMap", 6, |s| {
             s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
-            s.emit_struct_field("abs_path", 1, |s| self.abs_path.encode(s))?;
+            s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?;
             s.emit_struct_field("start_pos", 2, |s| self.start_pos.encode(s))?;
             s.emit_struct_field("end_pos", 3, |s| self.end_pos.encode(s))?;
             s.emit_struct_field("lines", 4, |s| {
@@ -453,8 +454,8 @@ impl Decodable for FileMap {
 
         d.read_struct("FileMap", 6, |d| {
             let name: String = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
-            let abs_path: Option =
-                d.read_struct_field("abs_path", 1, |d| Decodable::decode(d))?;
+            let name_was_remapped: bool =
+                d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?;
             let start_pos: BytePos = d.read_struct_field("start_pos", 2, |d| Decodable::decode(d))?;
             let end_pos: BytePos = d.read_struct_field("end_pos", 3, |d| Decodable::decode(d))?;
             let lines: Vec = d.read_struct_field("lines", 4, |d| {
@@ -489,7 +490,7 @@ impl Decodable for FileMap {
                 d.read_struct_field("multibyte_chars", 5, |d| Decodable::decode(d))?;
             Ok(FileMap {
                 name: name,
-                abs_path: abs_path,
+                name_was_remapped: name_was_remapped,
                 start_pos: start_pos,
                 end_pos: end_pos,
                 src: None,
diff --git a/src/test/codegen/remap_path_prefix.rs b/src/test/codegen/remap_path_prefix.rs
new file mode 100644
index 0000000000000..98e8180ed3854
--- /dev/null
+++ b/src/test/codegen/remap_path_prefix.rs
@@ -0,0 +1,19 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0  or the MIT license
+// , at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+
+// compile-flags: -g -Zremap-path-prefix-from={{cwd}} -Zremap-path-prefix-to=/the/cwd -Zremap-path-prefix-from={{src-base}} -Zremap-path-prefix-to=/the/src
+
+// CHECK: !DIFile(filename: "/the/src/remap_path_prefix.rs", directory: "/the/cwd")
+
+fn main() {
+    // We just check that the DIFile got remapped properly.
+}
diff --git a/src/test/compile-fail-fulldeps/qquote.rs b/src/test/compile-fail-fulldeps/qquote.rs
index 272bf1150cacb..3e2829adeb52e 100644
--- a/src/test/compile-fail-fulldeps/qquote.rs
+++ b/src/test/compile-fail-fulldeps/qquote.rs
@@ -16,12 +16,13 @@ extern crate syntax;
 extern crate syntax_pos;
 
 use syntax::ast;
+use syntax::codemap::FilePathMapping;
 use syntax::print::pprust;
 use syntax::symbol::Symbol;
 use syntax_pos::DUMMY_SP;
 
 fn main() {
-    let ps = syntax::parse::ParseSess::new();
+    let ps = syntax::parse::ParseSess::new(FilePathMapping::empty());
     let mut resolver = syntax::ext::base::DummyResolver;
     let mut cx = syntax::ext::base::ExtCtxt::new(
         &ps,
diff --git a/src/test/run-fail-fulldeps/qquote.rs b/src/test/run-fail-fulldeps/qquote.rs
index 5518ab47c2bd2..27b9e27be4385 100644
--- a/src/test/run-fail-fulldeps/qquote.rs
+++ b/src/test/run-fail-fulldeps/qquote.rs
@@ -24,7 +24,7 @@ use syntax::symbol::Symbol;
 use syntax_pos::DUMMY_SP;
 
 fn main() {
-    let ps = syntax::parse::ParseSess::new();
+    let ps = syntax::parse::ParseSess::new(codemap::FilePathMapping::empty());
     let mut resolver = syntax::ext::base::DummyResolver;
     let mut cx = syntax::ext::base::ExtCtxt::new(
         &ps,
diff --git a/src/test/run-pass-fulldeps/ast_stmt_expr_attr.rs b/src/test/run-pass-fulldeps/ast_stmt_expr_attr.rs
index 5139b68bce7fd..fc031f4a310c2 100644
--- a/src/test/run-pass-fulldeps/ast_stmt_expr_attr.rs
+++ b/src/test/run-pass-fulldeps/ast_stmt_expr_attr.rs
@@ -17,6 +17,7 @@ extern crate syntax;
 use syntax::ast::*;
 use syntax::attr::*;
 use syntax::ast;
+use syntax::codemap::FilePathMapping;
 use syntax::parse;
 use syntax::parse::{ParseSess, PResult};
 use syntax::parse::new_parser_from_source_str;
@@ -78,7 +79,7 @@ fn str_compare String>(e: &str, expected: &[T], actual: &[T], f:
 }
 
 fn check_expr_attrs(es: &str, expected: &[&str]) {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     let e = expr(es, &ps).expect("parse error");
     let actual = &e.attrs;
     str_compare(es,
@@ -88,7 +89,7 @@ fn check_expr_attrs(es: &str, expected: &[&str]) {
 }
 
 fn check_stmt_attrs(es: &str, expected: &[&str]) {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     let e = stmt(es, &ps).expect("parse error");
     let actual = e.node.attrs();
     str_compare(es,
@@ -98,7 +99,7 @@ fn check_stmt_attrs(es: &str, expected: &[&str]) {
 }
 
 fn reject_expr_parse(es: &str) {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     match expr(es, &ps) {
         Ok(_) => panic!("parser did not reject `{}`", es),
         Err(mut e) => e.cancel(),
@@ -106,7 +107,7 @@ fn reject_expr_parse(es: &str) {
 }
 
 fn reject_stmt_parse(es: &str) {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     match stmt(es, &ps) {
         Ok(_) => panic!("parser did not reject `{}`", es),
         Err(mut e) => e.cancel(),
diff --git a/src/test/run-pass-fulldeps/qquote.rs b/src/test/run-pass-fulldeps/qquote.rs
index 4a8246ec429c0..949aa8a9518c0 100644
--- a/src/test/run-pass-fulldeps/qquote.rs
+++ b/src/test/run-pass-fulldeps/qquote.rs
@@ -15,12 +15,13 @@
 extern crate syntax;
 extern crate syntax_pos;
 
+use syntax::codemap::FilePathMapping;
 use syntax::print::pprust::*;
 use syntax::symbol::Symbol;
 use syntax_pos::DUMMY_SP;
 
 fn main() {
-    let ps = syntax::parse::ParseSess::new();
+    let ps = syntax::parse::ParseSess::new(FilePathMapping::empty());
     let mut resolver = syntax::ext::base::DummyResolver;
     let mut cx = syntax::ext::base::ExtCtxt::new(
         &ps,
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index 522cd222c2691..0f653dfbcf07c 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -40,23 +40,24 @@ impl EarlyProps {
                     None,
                     &mut |ln| {
             props.ignore =
-                props.ignore || parse_name_directive(ln, "ignore-test") ||
-                parse_name_directive(ln, &ignore_target(config)) ||
-                parse_name_directive(ln, &ignore_architecture(config)) ||
-                parse_name_directive(ln, &ignore_stage(config)) ||
-                parse_name_directive(ln, &ignore_env(config)) ||
-                (config.mode == common::Pretty && parse_name_directive(ln, "ignore-pretty")) ||
+                props.ignore || config.parse_name_directive(ln, "ignore-test") ||
+                config.parse_name_directive(ln, &ignore_target(config)) ||
+                config.parse_name_directive(ln, &ignore_architecture(config)) ||
+                config.parse_name_directive(ln, &ignore_stage(config)) ||
+                config.parse_name_directive(ln, &ignore_env(config)) ||
+                (config.mode == common::Pretty &&
+                 config.parse_name_directive(ln, "ignore-pretty")) ||
                 (config.target != config.host &&
-                 parse_name_directive(ln, "ignore-cross-compile")) ||
+                 config.parse_name_directive(ln, "ignore-cross-compile")) ||
                 ignore_gdb(config, ln) ||
                 ignore_lldb(config, ln) ||
                 ignore_llvm(config, ln);
 
-            if let Some(s) = parse_aux_build(ln) {
+            if let Some(s) = config.parse_aux_build(ln) {
                 props.aux.push(s);
             }
 
-            props.should_fail = props.should_fail || parse_name_directive(ln, "should-fail");
+            props.should_fail = props.should_fail || config.parse_name_directive(ln, "should-fail");
         });
 
         return props;
@@ -80,7 +81,7 @@ impl EarlyProps {
             }
 
             if !line.contains("ignore-gdb-version") &&
-               parse_name_directive(line, "ignore-gdb") {
+               config.parse_name_directive(line, "ignore-gdb") {
                 return true;
             }
 
@@ -143,7 +144,7 @@ impl EarlyProps {
                 return false;
             }
 
-            if parse_name_directive(line, "ignore-lldb") {
+            if config.parse_name_directive(line, "ignore-lldb") {
                 return true;
             }
 
@@ -260,19 +261,23 @@ impl TestProps {
         }
     }
 
-    pub fn from_aux_file(&self, testfile: &Path, cfg: Option<&str>) -> Self {
+    pub fn from_aux_file(&self,
+                         testfile: &Path,
+                         cfg: Option<&str>,
+                         config: &Config)
+                         -> Self {
         let mut props = TestProps::new();
 
         // copy over select properties to the aux build:
         props.incremental_dir = self.incremental_dir.clone();
-        props.load_from(testfile, cfg);
+        props.load_from(testfile, cfg, config);
 
         props
     }
 
-    pub fn from_file(testfile: &Path) -> Self {
+    pub fn from_file(testfile: &Path, config: &Config) -> Self {
         let mut props = TestProps::new();
-        props.load_from(testfile, None);
+        props.load_from(testfile, None, config);
         props
     }
 
@@ -280,85 +285,88 @@ impl TestProps {
     /// tied to a particular revision `foo` (indicated by writing
     /// `//[foo]`), then the property is ignored unless `cfg` is
     /// `Some("foo")`.
-    pub fn load_from(&mut self, testfile: &Path, cfg: Option<&str>) {
+    pub fn load_from(&mut self,
+                     testfile: &Path,
+                     cfg: Option<&str>,
+                     config: &Config) {
         iter_header(testfile,
                     cfg,
                     &mut |ln| {
-            if let Some(ep) = parse_error_pattern(ln) {
+            if let Some(ep) = config.parse_error_pattern(ln) {
                 self.error_patterns.push(ep);
             }
 
-            if let Some(flags) = parse_compile_flags(ln) {
+            if let Some(flags) = config.parse_compile_flags(ln) {
                 self.compile_flags.extend(flags.split_whitespace()
                     .map(|s| s.to_owned()));
             }
 
-            if let Some(r) = parse_revisions(ln) {
+            if let Some(r) = config.parse_revisions(ln) {
                 self.revisions.extend(r);
             }
 
             if self.run_flags.is_none() {
-                self.run_flags = parse_run_flags(ln);
+                self.run_flags = config.parse_run_flags(ln);
             }
 
             if self.pp_exact.is_none() {
-                self.pp_exact = parse_pp_exact(ln, testfile);
+                self.pp_exact = config.parse_pp_exact(ln, testfile);
             }
 
             if !self.build_aux_docs {
-                self.build_aux_docs = parse_build_aux_docs(ln);
+                self.build_aux_docs = config.parse_build_aux_docs(ln);
             }
 
             if !self.force_host {
-                self.force_host = parse_force_host(ln);
+                self.force_host = config.parse_force_host(ln);
             }
 
             if !self.check_stdout {
-                self.check_stdout = parse_check_stdout(ln);
+                self.check_stdout = config.parse_check_stdout(ln);
             }
 
             if !self.no_prefer_dynamic {
-                self.no_prefer_dynamic = parse_no_prefer_dynamic(ln);
+                self.no_prefer_dynamic = config.parse_no_prefer_dynamic(ln);
             }
 
             if !self.pretty_expanded {
-                self.pretty_expanded = parse_pretty_expanded(ln);
+                self.pretty_expanded = config.parse_pretty_expanded(ln);
             }
 
-            if let Some(m) = parse_pretty_mode(ln) {
+            if let Some(m) = config.parse_pretty_mode(ln) {
                 self.pretty_mode = m;
             }
 
             if !self.pretty_compare_only {
-                self.pretty_compare_only = parse_pretty_compare_only(ln);
+                self.pretty_compare_only = config.parse_pretty_compare_only(ln);
             }
 
-            if let Some(ab) = parse_aux_build(ln) {
+            if let Some(ab) = config.parse_aux_build(ln) {
                 self.aux_builds.push(ab);
             }
 
-            if let Some(ee) = parse_env(ln, "exec-env") {
+            if let Some(ee) = config.parse_env(ln, "exec-env") {
                 self.exec_env.push(ee);
             }
 
-            if let Some(ee) = parse_env(ln, "rustc-env") {
+            if let Some(ee) = config.parse_env(ln, "rustc-env") {
                 self.rustc_env.push(ee);
             }
 
-            if let Some(cl) = parse_check_line(ln) {
+            if let Some(cl) = config.parse_check_line(ln) {
                 self.check_lines.push(cl);
             }
 
-            if let Some(of) = parse_forbid_output(ln) {
+            if let Some(of) = config.parse_forbid_output(ln) {
                 self.forbid_output.push(of);
             }
 
             if !self.must_compile_successfully {
-                self.must_compile_successfully = parse_must_compile_successfully(ln);
+                self.must_compile_successfully = config.parse_must_compile_successfully(ln);
             }
 
             if !self.check_test_line_numbers_match {
-                self.check_test_line_numbers_match = parse_check_test_line_numbers_match(ln);
+                self.check_test_line_numbers_match = config.parse_check_test_line_numbers_match(ln);
             }
         });
 
@@ -410,114 +418,118 @@ fn iter_header(testfile: &Path, cfg: Option<&str>, it: &mut FnMut(&str)) {
     return;
 }
 
-fn parse_error_pattern(line: &str) -> Option {
-    parse_name_value_directive(line, "error-pattern")
-}
+impl Config {
 
-fn parse_forbid_output(line: &str) -> Option {
-    parse_name_value_directive(line, "forbid-output")
-}
+    fn parse_error_pattern(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "error-pattern")
+    }
 
-fn parse_aux_build(line: &str) -> Option {
-    parse_name_value_directive(line, "aux-build")
-}
+    fn parse_forbid_output(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "forbid-output")
+    }
 
-fn parse_compile_flags(line: &str) -> Option {
-    parse_name_value_directive(line, "compile-flags")
-}
+    fn parse_aux_build(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "aux-build")
+    }
 
-fn parse_revisions(line: &str) -> Option> {
-    parse_name_value_directive(line, "revisions")
-        .map(|r| r.split_whitespace().map(|t| t.to_string()).collect())
-}
+    fn parse_compile_flags(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "compile-flags")
+    }
 
-fn parse_run_flags(line: &str) -> Option {
-    parse_name_value_directive(line, "run-flags")
-}
+    fn parse_revisions(&self, line: &str) -> Option> {
+        self.parse_name_value_directive(line, "revisions")
+            .map(|r| r.split_whitespace().map(|t| t.to_string()).collect())
+    }
 
-fn parse_check_line(line: &str) -> Option {
-    parse_name_value_directive(line, "check")
-}
+    fn parse_run_flags(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "run-flags")
+    }
 
-fn parse_force_host(line: &str) -> bool {
-    parse_name_directive(line, "force-host")
-}
+    fn parse_check_line(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "check")
+    }
 
-fn parse_build_aux_docs(line: &str) -> bool {
-    parse_name_directive(line, "build-aux-docs")
-}
+    fn parse_force_host(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "force-host")
+    }
 
-fn parse_check_stdout(line: &str) -> bool {
-    parse_name_directive(line, "check-stdout")
-}
+    fn parse_build_aux_docs(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "build-aux-docs")
+    }
 
-fn parse_no_prefer_dynamic(line: &str) -> bool {
-    parse_name_directive(line, "no-prefer-dynamic")
-}
+    fn parse_check_stdout(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "check-stdout")
+    }
 
-fn parse_pretty_expanded(line: &str) -> bool {
-    parse_name_directive(line, "pretty-expanded")
-}
+    fn parse_no_prefer_dynamic(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "no-prefer-dynamic")
+    }
 
-fn parse_pretty_mode(line: &str) -> Option {
-    parse_name_value_directive(line, "pretty-mode")
-}
+    fn parse_pretty_expanded(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "pretty-expanded")
+    }
 
-fn parse_pretty_compare_only(line: &str) -> bool {
-    parse_name_directive(line, "pretty-compare-only")
-}
+    fn parse_pretty_mode(&self, line: &str) -> Option {
+        self.parse_name_value_directive(line, "pretty-mode")
+    }
 
-fn parse_must_compile_successfully(line: &str) -> bool {
-    parse_name_directive(line, "must-compile-successfully")
-}
+    fn parse_pretty_compare_only(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "pretty-compare-only")
+    }
 
-fn parse_check_test_line_numbers_match(line: &str) -> bool {
-    parse_name_directive(line, "check-test-line-numbers-match")
-}
+    fn parse_must_compile_successfully(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "must-compile-successfully")
+    }
 
-fn parse_env(line: &str, name: &str) -> Option<(String, String)> {
-    parse_name_value_directive(line, name).map(|nv| {
-        // nv is either FOO or FOO=BAR
-        let mut strs: Vec = nv.splitn(2, '=')
-            .map(str::to_owned)
-            .collect();
+    fn parse_check_test_line_numbers_match(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "check-test-line-numbers-match")
+    }
 
-        match strs.len() {
-            1 => (strs.pop().unwrap(), "".to_owned()),
-            2 => {
-                let end = strs.pop().unwrap();
-                (strs.pop().unwrap(), end)
+    fn parse_env(&self, line: &str, name: &str) -> Option<(String, String)> {
+        self.parse_name_value_directive(line, name).map(|nv| {
+            // nv is either FOO or FOO=BAR
+            let mut strs: Vec = nv.splitn(2, '=')
+                .map(str::to_owned)
+                .collect();
+
+            match strs.len() {
+                1 => (strs.pop().unwrap(), "".to_owned()),
+                2 => {
+                    let end = strs.pop().unwrap();
+                    (strs.pop().unwrap(), end)
+                }
+                n => panic!("Expected 1 or 2 strings, not {}", n),
             }
-            n => panic!("Expected 1 or 2 strings, not {}", n),
-        }
-    })
-}
+        })
+    }
 
-fn parse_pp_exact(line: &str, testfile: &Path) -> Option {
-    if let Some(s) = parse_name_value_directive(line, "pp-exact") {
-        Some(PathBuf::from(&s))
-    } else {
-        if parse_name_directive(line, "pp-exact") {
-            testfile.file_name().map(PathBuf::from)
+    fn parse_pp_exact(&self, line: &str, testfile: &Path) -> Option {
+        if let Some(s) = self.parse_name_value_directive(line, "pp-exact") {
+            Some(PathBuf::from(&s))
         } else {
-            None
+            if self.parse_name_directive(line, "pp-exact") {
+                testfile.file_name().map(PathBuf::from)
+            } else {
+                None
+            }
         }
     }
-}
 
-fn parse_name_directive(line: &str, directive: &str) -> bool {
-    // This 'no-' rule is a quick hack to allow pretty-expanded and no-pretty-expanded to coexist
-    line.contains(directive) && !line.contains(&("no-".to_owned() + directive))
-}
+    fn parse_name_directive(&self, line: &str, directive: &str) -> bool {
+        // This 'no-' rule is a quick hack to allow pretty-expanded and
+        // no-pretty-expanded to coexist
+        line.contains(directive) && !line.contains(&("no-".to_owned() + directive))
+    }
 
-pub fn parse_name_value_directive(line: &str, directive: &str) -> Option {
-    let keycolon = format!("{}:", directive);
-    if let Some(colon) = line.find(&keycolon) {
-        let value = line[(colon + keycolon.len())..line.len()].to_owned();
-        debug!("{}: {}", directive, value);
-        Some(value)
-    } else {
-        None
+    pub fn parse_name_value_directive(&self, line: &str, directive: &str) -> Option {
+        let keycolon = format!("{}:", directive);
+        if let Some(colon) = line.find(&keycolon) {
+            let value = line[(colon + keycolon.len())..line.len()].to_owned();
+            debug!("{}: {}", directive, value);
+            Some(expand_variables(value, self))
+        } else {
+            None
+        }
     }
 }
 
@@ -528,3 +540,24 @@ pub fn lldb_version_to_int(version_string: &str) -> isize {
     let major: isize = version_string.parse().ok().expect(&error_string);
     return major;
 }
+
+fn expand_variables(mut value: String, config: &Config) -> String {
+    const CWD: &'static str = "{{cwd}}";
+    const SRC_BASE: &'static str = "{{src-base}}";
+    const BUILD_BASE: &'static str = "{{build-base}}";
+
+    if value.contains(CWD) {
+        let cwd = env::current_dir().unwrap();
+        value = value.replace(CWD, &cwd.to_string_lossy());
+    }
+
+    if value.contains(SRC_BASE) {
+        value = value.replace(SRC_BASE, &config.src_base.to_string_lossy());
+    }
+
+    if value.contains(BUILD_BASE) {
+        value = value.replace(BUILD_BASE, &config.build_base.to_string_lossy());
+    }
+
+    value
+}
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 7fb296c19f6ed..1348c8552496b 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -16,7 +16,6 @@ use errors::{self, ErrorKind, Error};
 use filetime::FileTime;
 use json;
 use header::TestProps;
-use header;
 use procsrv;
 use test::TestPaths;
 use uidiff;
@@ -57,7 +56,7 @@ pub fn run(config: Config, testpaths: &TestPaths) {
         print!("\n\n");
     }
     debug!("running {:?}", testpaths.file.display());
-    let base_props = TestProps::from_file(&testpaths.file);
+    let base_props = TestProps::from_file(&testpaths.file, &config);
 
     let base_cx = TestCx { config: &config,
                            props: &base_props,
@@ -70,7 +69,7 @@ pub fn run(config: Config, testpaths: &TestPaths) {
     } else {
         for revision in &base_props.revisions {
             let mut revision_props = base_props.clone();
-            revision_props.load_from(&testpaths.file, Some(&revision));
+            revision_props.load_from(&testpaths.file, Some(&revision), &config);
             let rev_cx = TestCx {
                 config: &config,
                 props: &revision_props,
@@ -867,13 +866,13 @@ actual:\n\
                     }
 
                     for &(ref command_directive, ref check_directive) in &directives {
-                        header::parse_name_value_directive(
+                        self.config.parse_name_value_directive(
                             &line,
                             &command_directive).map(|cmd| {
                                 commands.push(cmd)
                             });
 
-                        header::parse_name_value_directive(
+                        self.config.parse_name_value_directive(
                             &line,
                             &check_directive).map(|cmd| {
                                 check_lines.push(cmd)
@@ -1158,7 +1157,9 @@ actual:\n\
         if self.props.build_aux_docs {
             for rel_ab in &self.props.aux_builds {
                 let aux_testpaths = self.compute_aux_test_paths(rel_ab);
-                let aux_props = self.props.from_aux_file(&aux_testpaths.file, self.revision);
+                let aux_props = self.props.from_aux_file(&aux_testpaths.file,
+                                                         self.revision,
+                                                         self.config);
                 let aux_cx = TestCx {
                     config: self.config,
                     props: &aux_props,
@@ -1279,7 +1280,9 @@ actual:\n\
 
         for rel_ab in &self.props.aux_builds {
             let aux_testpaths = self.compute_aux_test_paths(rel_ab);
-            let aux_props = self.props.from_aux_file(&aux_testpaths.file, self.revision);
+            let aux_props = self.props.from_aux_file(&aux_testpaths.file,
+                                                     self.revision,
+                                                     self.config);
             let mut crate_type = if aux_props.no_prefer_dynamic {
                 Vec::new()
             } else {

From eb6308fc34bf6e88f5af59b0fddbd9af07cdf327 Mon Sep 17 00:00:00 2001
From: Michael Woerister 
Date: Tue, 25 Apr 2017 10:59:29 +0200
Subject: [PATCH 2/5] remap-path-prefix: Validate number of commandline
 arguments passed.

---
 src/librustc/session/config.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index 888ed2a6d18df..99c98f85c320a 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -1443,6 +1443,23 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         output_types.insert(OutputType::Exe, None);
     }
 
+    let remap_path_prefix_sources = debugging_opts.remap_path_prefix_from.len();
+    let remap_path_prefix_targets = debugging_opts.remap_path_prefix_from.len();
+
+    if remap_path_prefix_targets < remap_path_prefix_sources {
+        for source in &debugging_opts.remap_path_prefix_from[remap_path_prefix_targets..] {
+            early_error(error_format,
+                &format!("option `-Zremap-path-prefix-from='{}'` does not have \
+                         a corresponding `-Zremap-path-prefix-to`", source))
+        }
+    } else if remap_path_prefix_targets > remap_path_prefix_sources {
+        for target in &debugging_opts.remap_path_prefix_to[remap_path_prefix_sources..] {
+            early_error(error_format,
+                &format!("option `-Zremap-path-prefix-to='{}'` does not have \
+                          a corresponding `-Zremap-path-prefix-from`", target))
+        }
+    }
+
     let mut cg = build_codegen_options(matches, error_format);
 
     // Issue #30063: if user requests llvm-related output to one

From 5c62ce4a8246e244620d1ff72e657bdea0cd5d4a Mon Sep 17 00:00:00 2001
From: Michael Woerister 
Date: Wed, 26 Apr 2017 12:46:09 +0200
Subject: [PATCH 3/5] Make codegen test for remap-path-prefix more thorough.

---
 .../auxiliary/remap_path_prefix_aux.rs}       |  9 +++---
 src/test/codegen/remap_path_prefix/main.rs    | 30 +++++++++++++++++++
 2 files changed, 34 insertions(+), 5 deletions(-)
 rename src/test/codegen/{remap_path_prefix.rs => remap_path_prefix/auxiliary/remap_path_prefix_aux.rs} (61%)
 create mode 100644 src/test/codegen/remap_path_prefix/main.rs

diff --git a/src/test/codegen/remap_path_prefix.rs b/src/test/codegen/remap_path_prefix/auxiliary/remap_path_prefix_aux.rs
similarity index 61%
rename from src/test/codegen/remap_path_prefix.rs
rename to src/test/codegen/remap_path_prefix/auxiliary/remap_path_prefix_aux.rs
index 98e8180ed3854..5543a091680f1 100644
--- a/src/test/codegen/remap_path_prefix.rs
+++ b/src/test/codegen/remap_path_prefix/auxiliary/remap_path_prefix_aux.rs
@@ -10,10 +10,9 @@
 
 // ignore-tidy-linelength
 
-// compile-flags: -g -Zremap-path-prefix-from={{cwd}} -Zremap-path-prefix-to=/the/cwd -Zremap-path-prefix-from={{src-base}} -Zremap-path-prefix-to=/the/src
+// compile-flags: -g  -Zremap-path-prefix-from={{cwd}} -Zremap-path-prefix-to=/the/aux-cwd -Zremap-path-prefix-from={{src-base}}/remap_path_prefix/auxiliary -Zremap-path-prefix-to=/the/aux-src
 
-// CHECK: !DIFile(filename: "/the/src/remap_path_prefix.rs", directory: "/the/cwd")
-
-fn main() {
-    // We just check that the DIFile got remapped properly.
+#[inline]
+pub fn some_aux_function() -> i32 {
+    1234
 }
diff --git a/src/test/codegen/remap_path_prefix/main.rs b/src/test/codegen/remap_path_prefix/main.rs
new file mode 100644
index 0000000000000..26e4f04e1b83a
--- /dev/null
+++ b/src/test/codegen/remap_path_prefix/main.rs
@@ -0,0 +1,30 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0  or the MIT license
+// , at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+
+// compile-flags: -g  -C no-prepopulate-passes -Zremap-path-prefix-from={{cwd}} -Zremap-path-prefix-to=/the/cwd -Zremap-path-prefix-from={{src-base}} -Zremap-path-prefix-to=/the/src
+// aux-build:remap_path_prefix_aux.rs
+
+extern crate remap_path_prefix_aux;
+
+// Here we check that the expansion of the file!() macro is mapped.
+// CHECK: internal constant [34 x i8] c"/the/src/remap_path_prefix/main.rs"
+pub static FILE_PATH: &'static str = file!();
+
+fn main() {
+    remap_path_prefix_aux::some_aux_function();
+}
+
+// Here we check that local debuginfo is mapped correctly.
+// CHECK: !DIFile(filename: "/the/src/remap_path_prefix/main.rs", directory: "/the/cwd")
+
+// And here that debuginfo from other crates are expanded to absolute paths.
+// CHECK: !DIFile(filename: "/the/aux-src/remap_path_prefix_aux.rs", directory: "")

From ab9691d5b7a22ba6b37a9621a3c66c2626bd38a5 Mon Sep 17 00:00:00 2001
From: Michael Woerister 
Date: Wed, 26 Apr 2017 12:20:21 +0200
Subject: [PATCH 4/5] Add some documentation for -Zremap-path-prefix to the
 unstable book

---
 src/doc/unstable-book/src/SUMMARY.md          |  1 +
 .../src/compiler-flags/remap-path-prefix.md   | 37 +++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 src/doc/unstable-book/src/compiler-flags/remap-path-prefix.md

diff --git a/src/doc/unstable-book/src/SUMMARY.md b/src/doc/unstable-book/src/SUMMARY.md
index 2cb3763011218..0d0485dc872d7 100644
--- a/src/doc/unstable-book/src/SUMMARY.md
+++ b/src/doc/unstable-book/src/SUMMARY.md
@@ -2,6 +2,7 @@
 
 - [Compiler flags](compiler-flags.md)
     - [linker_flavor](compiler-flags/linker-flavor.md)
+    - [remap_path_prefix](compiler-flags/remap-path-prefix.md)
 - [Language features](language-features.md)
     - [abi_msp430_interrupt](language-features/abi-msp430-interrupt.md)
     - [abi_ptx](language-features/abi-ptx.md)
diff --git a/src/doc/unstable-book/src/compiler-flags/remap-path-prefix.md b/src/doc/unstable-book/src/compiler-flags/remap-path-prefix.md
new file mode 100644
index 0000000000000..8ca04d2532592
--- /dev/null
+++ b/src/doc/unstable-book/src/compiler-flags/remap-path-prefix.md
@@ -0,0 +1,37 @@
+# `remap-path-prefix`
+
+The tracking issue for this feature is: [#41555](https://github.com/rust-lang/rust/issues/41555)
+
+------------------------
+
+The `-Z remap-path-prefix-from`, `-Z remap-path-prefix-to` commandline option
+pair allows to replace prefixes of any file paths the compiler emits in various
+places. This is useful for bringing debuginfo paths into a well-known form and
+for achieving reproducible builds independent of the directory the compiler was
+executed in. All paths emitted by the compiler are affected, including those in
+error messages.
+
+In order to map all paths starting with `/home/foo/my-project/src` to
+`/sources/my-project`, one would invoke the compiler as follows:
+
+```text
+rustc -Zremap-path-prefix-from="/home/foo/my-project/src" -Zremap-path-prefix-to="/sources/my-project"
+```
+
+Debuginfo for code from the file `/home/foo/my-project/src/foo/mod.rs`,
+for example, would then point debuggers to `/sources/my-project/foo/mod.rs`
+instead of the original file.
+
+The options can be specified multiple times when multiple prefixes should be
+mapped:
+
+```text
+rustc -Zremap-path-prefix-from="/home/foo/my-project/src" \
+      -Zremap-path-prefix-to="/sources/my-project" \
+      -Zremap-path-prefix-from="/home/foo/my-project/build-dir" \
+      -Zremap-path-prefix-to="/stable-build-dir"
+```
+
+When the options are given multiple times, the nth `-from` will be matched up
+with the nth `-to` and they can appear anywhere on the commandline. Mappings
+specified later on the line will take precedence over earlier ones.

From 8ea050d89dbdb133ee6f17314a1b1acfbc42363f Mon Sep 17 00:00:00 2001
From: Michael Woerister 
Date: Fri, 28 Apr 2017 13:30:07 +0200
Subject: [PATCH 5/5] Disable path remapping test on Windows.

---
 src/test/codegen/remap_path_prefix/main.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/test/codegen/remap_path_prefix/main.rs b/src/test/codegen/remap_path_prefix/main.rs
index 26e4f04e1b83a..eb00c91ba5f39 100644
--- a/src/test/codegen/remap_path_prefix/main.rs
+++ b/src/test/codegen/remap_path_prefix/main.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-windows
 // ignore-tidy-linelength
 
 // compile-flags: -g  -C no-prepopulate-passes -Zremap-path-prefix-from={{cwd}} -Zremap-path-prefix-to=/the/cwd -Zremap-path-prefix-from={{src-base}} -Zremap-path-prefix-to=/the/src