// Copyright 2012-2014 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. use back::archive::{Archive, METADATA_FILENAME}; use back::rpath; use driver::driver::{CrateTranslation, OutputFilenames}; use driver::session::Session; use driver::session; use lib::llvm::llvm; use lib::llvm::ModuleRef; use lib; use metadata::common::LinkMeta; use metadata::{encoder, cstore, filesearch, csearch}; use middle::trans::context::CrateContext; use middle::trans::common::gensym_name; use middle::ty; use util::common::time; use util::ppaux; use util::sha2::{Digest, Sha256}; use std::c_str::ToCStr; use std::char; use std::os::consts::{macos, freebsd, linux, android, win32}; use std::ptr; use std::run; use std::str; use std::io; use std::io::fs; use serialize::hex::ToHex; use extra::tempfile::TempDir; use syntax::abi; use syntax::ast; use syntax::ast_map::{PathElem, PathElems, PathName}; use syntax::ast_map; use syntax::attr; use syntax::attr::AttrMetaMethods; use syntax::crateid::CrateId; use syntax::parse::token; #[deriving(Clone, Eq, TotalOrd, TotalEq)] pub enum OutputType { OutputTypeBitcode, OutputTypeAssembly, OutputTypeLlvmAssembly, OutputTypeObject, OutputTypeExe, } pub fn llvm_err(sess: Session, msg: ~str) -> ! { unsafe { let cstr = llvm::LLVMRustGetLastError(); if cstr == ptr::null() { sess.fatal(msg); } else { sess.fatal(msg + ": " + str::raw::from_c_str(cstr)); } } } pub fn WriteOutputFile( sess: Session, Target: lib::llvm::TargetMachineRef, PM: lib::llvm::PassManagerRef, M: ModuleRef, Output: &Path, FileType: lib::llvm::FileType) { unsafe { Output.with_c_str(|Output| { let result = llvm::LLVMRustWriteOutputFile( Target, PM, M, Output, FileType); if !result { llvm_err(sess, ~"could not write output"); } }) } } pub mod write { use back::lto; use back::link::{WriteOutputFile, OutputType}; use back::link::{OutputTypeAssembly, OutputTypeBitcode}; use back::link::{OutputTypeExe, OutputTypeLlvmAssembly}; use back::link::{OutputTypeObject}; use driver::driver::{CrateTranslation, OutputFilenames}; use driver::session::Session; use driver::session; use lib::llvm::llvm; use lib::llvm::{ModuleRef, TargetMachineRef, PassManagerRef}; use lib; use util::common::time; use syntax::abi; use std::c_str::ToCStr; use std::libc::{c_uint, c_int}; use std::run; use std::str; // On android, we by default compile for armv7 processors. This enables // things like double word CAS instructions (rather than emulating them) // which are *far* more efficient. This is obviously undesirable in some // cases, so if any sort of target feature is specified we don't append v7 // to the feature list. fn target_feature<'a>(sess: &'a Session) -> &'a str { match sess.targ_cfg.os { abi::OsAndroid => { if "" == sess.opts.cg.target_feature { "+v7" } else { sess.opts.cg.target_feature.as_slice() } } _ => sess.opts.cg.target_feature.as_slice() } } pub fn run_passes(sess: Session, trans: &CrateTranslation, output_types: &[OutputType], output: &OutputFilenames) { let llmod = trans.module; let llcx = trans.context; unsafe { configure_llvm(sess); if sess.opts.cg.save_temps { output.with_extension("no-opt.bc").with_c_str(|buf| { llvm::LLVMWriteBitcodeToFile(llmod, buf); }) } let OptLevel = match sess.opts.optimize { session::No => lib::llvm::CodeGenLevelNone, session::Less => lib::llvm::CodeGenLevelLess, session::Default => lib::llvm::CodeGenLevelDefault, session::Aggressive => lib::llvm::CodeGenLevelAggressive, }; let use_softfp = sess.opts.cg.soft_float; // FIXME: #11906: Omitting frame pointers breaks retrieving the value of a parameter. // FIXME: #11954: mac64 unwinding may not work with fp elim let no_fp_elim = sess.opts.debuginfo || (sess.targ_cfg.os == abi::OsMacos && sess.targ_cfg.arch == abi::X86_64); let tm = sess.targ_cfg.target_strs.target_triple.with_c_str(|T| { sess.opts.cg.target_cpu.with_c_str(|CPU| { target_feature(&sess).with_c_str(|Features| { llvm::LLVMRustCreateTargetMachine( T, CPU, Features, lib::llvm::CodeModelDefault, lib::llvm::RelocPIC, OptLevel, true, use_softfp, no_fp_elim ) }) }) }); // Create the two optimizing pass managers. These mirror what clang // does, and are by populated by LLVM's default PassManagerBuilder. // Each manager has a different set of passes, but they also share // some common passes. let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod); let mpm = llvm::LLVMCreatePassManager(); // If we're verifying or linting, add them to the function pass // manager. let addpass = |pass: &str| { pass.with_c_str(|s| llvm::LLVMRustAddPass(fpm, s)) }; if !sess.no_verify() { assert!(addpass("verify")); } if !sess.opts.cg.no_prepopulate_passes { llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod); llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod); populate_llvm_passes(fpm, mpm, llmod, OptLevel); } for pass in sess.opts.cg.passes.iter() { pass.with_c_str(|s| { if !llvm::LLVMRustAddPass(mpm, s) { sess.warn(format!("unknown pass {}, ignoring", *pass)); } }) } // Finally, run the actual optimization passes time(sess.time_passes(), "llvm function passes", (), |()| llvm::LLVMRustRunFunctionPassManager(fpm, llmod)); time(sess.time_passes(), "llvm module passes", (), |()| llvm::LLVMRunPassManager(mpm, llmod)); // Deallocate managers that we're now done with llvm::LLVMDisposePassManager(fpm); llvm::LLVMDisposePassManager(mpm); // Emit the bytecode if we're either saving our temporaries or // emitting an rlib. Whenever an rlib is created, the bytecode is // inserted into the archive in order to allow LTO against it. let crate_types = sess.crate_types.borrow(); if sess.opts.cg.save_temps || (crate_types.get().contains(&session::CrateTypeRlib) && sess.opts.output_types.contains(&OutputTypeExe)) { output.temp_path(OutputTypeBitcode).with_c_str(|buf| { llvm::LLVMWriteBitcodeToFile(llmod, buf); }) } if sess.lto() { time(sess.time_passes(), "all lto passes", (), |()| lto::run(sess, llmod, tm, trans.reachable)); if sess.opts.cg.save_temps { output.with_extension("lto.bc").with_c_str(|buf| { llvm::LLVMWriteBitcodeToFile(llmod, buf); }) } } // A codegen-specific pass manager is used to generate object // files for an LLVM module. // // Apparently each of these pass managers is a one-shot kind of // thing, so we create a new one for each type of output. The // pass manager passed to the closure should be ensured to not // escape the closure itself, and the manager should only be // used once. fn with_codegen(tm: TargetMachineRef, llmod: ModuleRef, f: |PassManagerRef|) { unsafe { let cpm = llvm::LLVMCreatePassManager(); llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod); llvm::LLVMRustAddLibraryInfo(cpm, llmod); f(cpm); llvm::LLVMDisposePassManager(cpm); } } let mut object_file = None; let mut needs_metadata = false; for output_type in output_types.iter() { let path = output.path(*output_type); match *output_type { OutputTypeBitcode => { path.with_c_str(|buf| { llvm::LLVMWriteBitcodeToFile(llmod, buf); }) } OutputTypeLlvmAssembly => { path.with_c_str(|output| { with_codegen(tm, llmod, |cpm| { llvm::LLVMRustPrintModule(cpm, llmod, output); }) }) } OutputTypeAssembly => { // If we're not using the LLVM assembler, this function // could be invoked specially with output_type_assembly, // so in this case we still want the metadata object // file. let ty = OutputTypeAssembly; let path = if sess.opts.output_types.contains(&ty) { path } else { needs_metadata = true; output.temp_path(OutputTypeAssembly) }; with_codegen(tm, llmod, |cpm| { WriteOutputFile(sess, tm, cpm, llmod, &path, lib::llvm::AssemblyFile); }); } OutputTypeObject => { object_file = Some(path); } OutputTypeExe => { object_file = Some(output.temp_path(OutputTypeObject)); needs_metadata = true; } } } time(sess.time_passes(), "codegen passes", (), |()| { match object_file { Some(ref path) => { with_codegen(tm, llmod, |cpm| { WriteOutputFile(sess, tm, cpm, llmod, path, lib::llvm::ObjectFile); }); } None => {} } if needs_metadata { with_codegen(tm, trans.metadata_module, |cpm| { let out = output.temp_path(OutputTypeObject) .with_extension("metadata.o"); WriteOutputFile(sess, tm, cpm, trans.metadata_module, &out, lib::llvm::ObjectFile); }) } }); llvm::LLVMRustDisposeTargetMachine(tm); llvm::LLVMDisposeModule(trans.metadata_module); llvm::LLVMDisposeModule(llmod); llvm::LLVMContextDispose(llcx); if sess.time_llvm_passes() { llvm::LLVMRustPrintPassTimings(); } } } pub fn run_assembler(sess: Session, outputs: &OutputFilenames) { let cc = super::get_cc_prog(sess); let assembly = outputs.temp_path(OutputTypeAssembly); let object = outputs.path(OutputTypeObject); // FIXME (#9639): This needs to handle non-utf8 paths let args = [ ~"-c", ~"-o", object.as_str().unwrap().to_owned(), assembly.as_str().unwrap().to_owned()]; debug!("{} '{}'", cc, args.connect("' '")); match run::process_output(cc, args) { Ok(prog) => { if !prog.status.success() { sess.err(format!("linking with `{}` failed: {}", cc, prog.status)); sess.note(format!("{} arguments: '{}'", cc, args.connect("' '"))); sess.note(str::from_utf8_owned(prog.error + prog.output).unwrap()); sess.abort_if_errors(); } }, Err(e) => { sess.err(format!("could not exec the linker `{}`: {}", cc, e)); sess.abort_if_errors(); } } } unsafe fn configure_llvm(sess: Session) { use sync::one::{Once, ONCE_INIT}; static mut INIT: Once = ONCE_INIT; // Copy what clang does by turning on loop vectorization at O2 and // slp vectorization at O3 let vectorize_loop = !sess.opts.cg.no_vectorize_loops && (sess.opts.optimize == session::Default || sess.opts.optimize == session::Aggressive); let vectorize_slp = !sess.opts.cg.no_vectorize_slp && sess.opts.optimize == session::Aggressive; let mut llvm_c_strs = ~[]; let mut llvm_args = ~[]; { let add = |arg: &str| { let s = arg.to_c_str(); llvm_args.push(s.with_ref(|p| p)); llvm_c_strs.push(s); }; add("rustc"); // fake program name if vectorize_loop { add("-vectorize-loops"); } if vectorize_slp { add("-vectorize-slp"); } if sess.time_llvm_passes() { add("-time-passes"); } if sess.print_llvm_passes() { add("-debug-pass=Structure"); } for arg in sess.opts.cg.llvm_args.iter() { add(*arg); } } INIT.doit(|| { llvm::LLVMInitializePasses(); // Only initialize the platforms supported by Rust here, because // using --llvm-root will have multiple platforms that rustllvm // doesn't actually link to and it's pointless to put target info // into the registry that Rust cannot generate machine code for. llvm::LLVMInitializeX86TargetInfo(); llvm::LLVMInitializeX86Target(); llvm::LLVMInitializeX86TargetMC(); llvm::LLVMInitializeX86AsmPrinter(); llvm::LLVMInitializeX86AsmParser(); llvm::LLVMInitializeARMTargetInfo(); llvm::LLVMInitializeARMTarget(); llvm::LLVMInitializeARMTargetMC(); llvm::LLVMInitializeARMAsmPrinter(); llvm::LLVMInitializeARMAsmParser(); llvm::LLVMInitializeMipsTargetInfo(); llvm::LLVMInitializeMipsTarget(); llvm::LLVMInitializeMipsTargetMC(); llvm::LLVMInitializeMipsAsmPrinter(); llvm::LLVMInitializeMipsAsmParser(); llvm::LLVMRustSetLLVMOptions(llvm_args.len() as c_int, llvm_args.as_ptr()); }); } unsafe fn populate_llvm_passes(fpm: lib::llvm::PassManagerRef, mpm: lib::llvm::PassManagerRef, llmod: ModuleRef, opt: lib::llvm::CodeGenOptLevel) { // Create the PassManagerBuilder for LLVM. We configure it with // reasonable defaults and prepare it to actually populate the pass // manager. let builder = llvm::LLVMPassManagerBuilderCreate(); match opt { lib::llvm::CodeGenLevelNone => { // Don't add lifetime intrinsics at O0 llvm::LLVMRustAddAlwaysInlinePass(builder, false); } lib::llvm::CodeGenLevelLess => { llvm::LLVMRustAddAlwaysInlinePass(builder, true); } // numeric values copied from clang lib::llvm::CodeGenLevelDefault => { llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225); } lib::llvm::CodeGenLevelAggressive => { llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275); } } llvm::LLVMPassManagerBuilderSetOptLevel(builder, opt as c_uint); llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod); // Use the builder to populate the function/module pass managers. llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(builder, fpm); llvm::LLVMPassManagerBuilderPopulateModulePassManager(builder, mpm); llvm::LLVMPassManagerBuilderDispose(builder); } } /* * Name mangling and its relationship to metadata. This is complex. Read * carefully. * * The semantic model of Rust linkage is, broadly, that "there's no global * namespace" between crates. Our aim is to preserve the illusion of this * model despite the fact that it's not *quite* possible to implement on * modern linkers. We initially didn't use system linkers at all, but have * been convinced of their utility. * * There are a few issues to handle: * * - Linkers operate on a flat namespace, so we have to flatten names. * We do this using the C++ namespace-mangling technique. Foo::bar * symbols and such. * * - Symbols with the same name but different types need to get different * linkage-names. We do this by hashing a string-encoding of the type into * a fixed-size (currently 16-byte hex) cryptographic hash function (CHF: * we use SHA256) to "prevent collisions". This is not airtight but 16 hex * digits on uniform probability means you're going to need 2**32 same-name * symbols in the same process before you're even hitting birthday-paradox * collision probability. * * - Symbols in different crates but with same names "within" the crate need * to get different linkage-names. * * - The hash shown in the filename needs to be predictable and stable for * build tooling integration. It also needs to be using a hash function * which is easy to use from Python, make, etc. * * So here is what we do: * * - Consider the package id; every crate has one (specified with crate_id * attribute). If a package id isn't provided explicitly, we infer a * versionless one from the output name. The version will end up being 0.0 * in this case. CNAME and CVERS are taken from this package id. For * example, github.com/mozilla/CNAME#CVERS. * * - Define CMH as SHA256(crateid). * * - Define CMH8 as the first 8 characters of CMH. * * - Compile our crate to lib CNAME-CMH8-CVERS.so * * - Define STH(sym) as SHA256(CMH, type_str(sym)) * * - Suffix a mangled sym with ::STH@CVERS, so that it is unique in the * name, non-name metadata, and type sense, and versioned in the way * system linkers understand. */ pub fn build_link_meta(attrs: &[ast::Attribute], output: &OutputFilenames, symbol_hasher: &mut Sha256) -> LinkMeta { // This calculates CMH as defined above fn crate_hash(symbol_hasher: &mut Sha256, crateid: &CrateId) -> ~str { symbol_hasher.reset(); symbol_hasher.input_str(crateid.to_str()); truncated_hash_result(symbol_hasher) } let crateid = match attr::find_crateid(attrs) { None => from_str(output.out_filestem).unwrap(), Some(s) => s, }; let hash = crate_hash(symbol_hasher, &crateid); LinkMeta { crateid: crateid, crate_hash: hash, } } fn truncated_hash_result(symbol_hasher: &mut Sha256) -> ~str { let output = symbol_hasher.result_bytes(); // 64 bits should be enough to avoid collisions. output.slice_to(8).to_hex() } // This calculates STH for a symbol, as defined above fn symbol_hash(tcx: ty::ctxt, symbol_hasher: &mut Sha256, t: ty::t, link_meta: &LinkMeta) -> ~str { // NB: do *not* use abbrevs here as we want the symbol names // to be independent of one another in the crate. symbol_hasher.reset(); symbol_hasher.input_str(link_meta.crateid.name); symbol_hasher.input_str("-"); symbol_hasher.input_str(link_meta.crate_hash); symbol_hasher.input_str("-"); symbol_hasher.input_str(encoder::encoded_ty(tcx, t)); let mut hash = truncated_hash_result(symbol_hasher); // Prefix with 'h' so that it never blends into adjacent digits hash.unshift_char('h'); hash } fn get_symbol_hash(ccx: &CrateContext, t: ty::t) -> ~str { match ccx.type_hashcodes.borrow().get().find(&t) { Some(h) => return h.to_str(), None => {} } let mut type_hashcodes = ccx.type_hashcodes.borrow_mut(); let mut symbol_hasher = ccx.symbol_hasher.borrow_mut(); let hash = symbol_hash(ccx.tcx, symbol_hasher.get(), t, &ccx.link_meta); type_hashcodes.get().insert(t, hash.clone()); hash } // Name sanitation. LLVM will happily accept identifiers with weird names, but // gas doesn't! // gas accepts the following characters in symbols: a-z, A-Z, 0-9, ., _, $ pub fn sanitize(s: &str) -> ~str { let mut result = ~""; for c in s.chars() { match c { // Escape these with $ sequences '@' => result.push_str("$SP$"), '~' => result.push_str("$UP$"), '*' => result.push_str("$RP$"), '&' => result.push_str("$BP$"), '<' => result.push_str("$LT$"), '>' => result.push_str("$GT$"), '(' => result.push_str("$LP$"), ')' => result.push_str("$RP$"), ',' => result.push_str("$C$"), // '.' doesn't occur in types and functions, so reuse it // for ':' and '-' '-' | ':' => result.push_char('.'), // These are legal symbols 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' | '.' | '$' => result.push_char(c), _ => { let mut tstr = ~""; char::escape_unicode(c, |c| tstr.push_char(c)); result.push_char('$'); result.push_str(tstr.slice_from(1)); } } } // Underscore-qualify anything that didn't start as an ident. if result.len() > 0u && result[0] != '_' as u8 && ! char::is_XID_start(result[0] as char) { return ~"_" + result; } return result; } pub fn mangle>(mut path: PI, hash: Option<&str>, vers: Option<&str>) -> ~str { // Follow C++ namespace-mangling style, see // http://en.wikipedia.org/wiki/Name_mangling for more info. // // It turns out that on OSX you can actually have arbitrary symbols in // function names (at least when given to LLVM), but this is not possible // when using unix's linker. Perhaps one day when we just use a linker from LLVM // we won't need to do this name mangling. The problem with name mangling is // that it seriously limits the available characters. For example we can't // have things like &T or ~[T] in symbol names when one would theoretically // want them for things like impls of traits on that type. // // To be able to work on all platforms and get *some* reasonable output, we // use C++ name-mangling. let mut n = ~"_ZN"; // _Z == Begin name-sequence, N == nested fn push(n: &mut ~str, s: &str) { let sani = sanitize(s); n.push_str(format!("{}{}", sani.len(), sani)); } // First, connect each component with pairs. for e in path { push(&mut n, token::get_name(e.name()).get().as_slice()) } match hash { Some(s) => push(&mut n, s), None => {} } match vers { Some(s) => push(&mut n, s), None => {} } n.push_char('E'); // End name-sequence. n } pub fn exported_name(path: PathElems, hash: &str, vers: &str) -> ~str { // The version will get mangled to have a leading '_', but it makes more // sense to lead with a 'v' b/c this is a version... let vers = if vers.len() > 0 && !char::is_XID_start(vers.char_at(0)) { "v" + vers } else { vers.to_owned() }; mangle(path, Some(hash), Some(vers.as_slice())) } pub fn mangle_exported_name(ccx: &CrateContext, path: PathElems, t: ty::t, id: ast::NodeId) -> ~str { let mut hash = get_symbol_hash(ccx, t); // Paths can be completely identical for different nodes, // e.g. `fn foo() { { fn a() {} } { fn a() {} } }`, so we // generate unique characters from the node id. For now // hopefully 3 characters is enough to avoid collisions. static EXTRA_CHARS: &'static str = "abcdefghijklmnopqrstuvwxyz\ ABCDEFGHIJKLMNOPQRSTUVWXYZ\ 0123456789"; let id = id as uint; let extra1 = id % EXTRA_CHARS.len(); let id = id / EXTRA_CHARS.len(); let extra2 = id % EXTRA_CHARS.len(); let id = id / EXTRA_CHARS.len(); let extra3 = id % EXTRA_CHARS.len(); hash.push_char(EXTRA_CHARS[extra1] as char); hash.push_char(EXTRA_CHARS[extra2] as char); hash.push_char(EXTRA_CHARS[extra3] as char); exported_name(path, hash, ccx.link_meta.crateid.version_or_default()) } pub fn mangle_internal_name_by_type_only(ccx: &CrateContext, t: ty::t, name: &str) -> ~str { let s = ppaux::ty_to_short_str(ccx.tcx, t); let path = [PathName(token::intern(name)), PathName(token::intern(s))]; let hash = get_symbol_hash(ccx, t); mangle(ast_map::Values(path.iter()), Some(hash.as_slice()), None) } pub fn mangle_internal_name_by_type_and_seq(ccx: &CrateContext, t: ty::t, name: &str) -> ~str { let s = ppaux::ty_to_str(ccx.tcx, t); let path = [PathName(token::intern(s)), gensym_name(name)]; let hash = get_symbol_hash(ccx, t); mangle(ast_map::Values(path.iter()), Some(hash.as_slice()), None) } pub fn mangle_internal_name_by_path_and_seq(path: PathElems, flav: &str) -> ~str { mangle(path.chain(Some(gensym_name(flav)).move_iter()), None, None) } pub fn output_lib_filename(lm: &LinkMeta) -> ~str { format!("{}-{}-{}", lm.crateid.name, lm.crate_hash.slice_chars(0, 8), lm.crateid.version_or_default()) } pub fn get_cc_prog(sess: Session) -> ~str { match sess.opts.cg.linker { Some(ref linker) => return linker.to_owned(), None => {} } // In the future, FreeBSD will use clang as default compiler. // It would be flexible to use cc (system's default C compiler) // instead of hard-coded gcc. // For win32, there is no cc command, so we add a condition to make it use gcc. match sess.targ_cfg.os { abi::OsWin32 => return ~"gcc", _ => {}, } get_system_tool(sess, "cc") } pub fn get_ar_prog(sess: Session) -> ~str { match sess.opts.cg.ar { Some(ref ar) => return ar.to_owned(), None => {} } get_system_tool(sess, "ar") } fn get_system_tool(sess: Session, tool: &str) -> ~str { match sess.targ_cfg.os { abi::OsAndroid => match sess.opts.cg.android_cross_path { Some(ref path) => { let tool_str = match tool { "cc" => "gcc", _ => tool }; format!("{}/bin/arm-linux-androideabi-{}", *path, tool_str) } None => { sess.fatal(format!("need Android NDK path for the '{}' tool \ (-C android-cross-path)", tool)) } }, _ => tool.to_owned(), } } fn remove(sess: Session, path: &Path) { match fs::unlink(path) { Ok(..) => {} Err(e) => { sess.err(format!("failed to remove {}: {}", path.display(), e)); } } } /// Perform the linkage portion of the compilation phase. This will generate all /// of the requested outputs for this compilation session. pub fn link_binary(sess: Session, trans: &CrateTranslation, outputs: &OutputFilenames, lm: &LinkMeta) -> ~[Path] { let mut out_filenames = ~[]; let crate_types = sess.crate_types.borrow(); for &crate_type in crate_types.get().iter() { let out_file = link_binary_output(sess, trans, crate_type, outputs, lm); out_filenames.push(out_file); } // Remove the temporary object file and metadata if we aren't saving temps if !sess.opts.cg.save_temps { let obj_filename = outputs.temp_path(OutputTypeObject); if !sess.opts.output_types.contains(&OutputTypeObject) { remove(sess, &obj_filename); } remove(sess, &obj_filename.with_extension("metadata.o")); } out_filenames } fn is_writeable(p: &Path) -> bool { match p.stat() { Err(..) => true, Ok(m) => m.perm & io::UserWrite == io::UserWrite } } pub fn filename_for_input(sess: &Session, crate_type: session::CrateType, lm: &LinkMeta, out_filename: &Path) -> Path { let libname = output_lib_filename(lm); match crate_type { session::CrateTypeRlib => { out_filename.with_filename(format!("lib{}.rlib", libname)) } session::CrateTypeDylib => { let (prefix, suffix) = match sess.targ_cfg.os { abi::OsWin32 => (win32::DLL_PREFIX, win32::DLL_SUFFIX), abi::OsMacos => (macos::DLL_PREFIX, macos::DLL_SUFFIX), abi::OsLinux => (linux::DLL_PREFIX, linux::DLL_SUFFIX), abi::OsAndroid => (android::DLL_PREFIX, android::DLL_SUFFIX), abi::OsFreebsd => (freebsd::DLL_PREFIX, freebsd::DLL_SUFFIX), }; out_filename.with_filename(format!("{}{}{}", prefix, libname, suffix)) } session::CrateTypeStaticlib => { out_filename.with_filename(format!("lib{}.a", libname)) } session::CrateTypeExecutable => out_filename.clone(), } } fn link_binary_output(sess: Session, trans: &CrateTranslation, crate_type: session::CrateType, outputs: &OutputFilenames, lm: &LinkMeta) -> Path { let obj_filename = outputs.temp_path(OutputTypeObject); let out_filename = match outputs.single_output_file { Some(ref file) => file.clone(), None => { let out_filename = outputs.path(OutputTypeExe); filename_for_input(&sess, crate_type, lm, &out_filename) } }; // Make sure the output and obj_filename are both writeable. // Mac, FreeBSD, and Windows system linkers check this already -- // however, the Linux linker will happily overwrite a read-only file. // We should be consistent. let obj_is_writeable = is_writeable(&obj_filename); let out_is_writeable = is_writeable(&out_filename); if !out_is_writeable { sess.fatal(format!("output file {} is not writeable -- check its permissions.", out_filename.display())); } else if !obj_is_writeable { sess.fatal(format!("object file {} is not writeable -- check its permissions.", obj_filename.display())); } match crate_type { session::CrateTypeRlib => { link_rlib(sess, Some(trans), &obj_filename, &out_filename); } session::CrateTypeStaticlib => { link_staticlib(sess, &obj_filename, &out_filename); } session::CrateTypeExecutable => { link_natively(sess, false, &obj_filename, &out_filename); } session::CrateTypeDylib => { link_natively(sess, true, &obj_filename, &out_filename); } } out_filename } // Create an 'rlib' // // An rlib in its current incarnation is essentially a renamed .a file. The // rlib primarily contains the object file of the crate, but it also contains // all of the object files from native libraries. This is done by unzipping // native libraries and inserting all of the contents into this archive. fn link_rlib(sess: Session, trans: Option<&CrateTranslation>, // None == no metadata/bytecode obj_filename: &Path, out_filename: &Path) -> Archive { let mut a = Archive::create(sess, out_filename, obj_filename); let used_libraries = sess.cstore.get_used_libraries(); let used_libraries = used_libraries.borrow(); for &(ref l, kind) in used_libraries.get().iter() { match kind { cstore::NativeStatic => { a.add_native_library(l.as_slice()).unwrap(); } cstore::NativeFramework | cstore::NativeUnknown => {} } } // Note that it is important that we add all of our non-object "magical // files" *after* all of the object files in the archive. The reason for // this is as follows: // // * When performing LTO, this archive will be modified to remove // obj_filename from above. The reason for this is described below. // // * When the system linker looks at an archive, it will attempt to // determine the architecture of the archive in order to see whether its // linkable. // // The algorithm for this detection is: iterate over the files in the // archive. Skip magical SYMDEF names. Interpret the first file as an // object file. Read architecture from the object file. // // * As one can probably see, if "metadata" and "foo.bc" were placed // before all of the objects, then the architecture of this archive would // not be correctly inferred once 'foo.o' is removed. // // Basically, all this means is that this code should not move above the // code above. match trans { Some(trans) => { // Instead of putting the metadata in an object file section, rlibs // contain the metadata in a separate file. We use a temp directory // here so concurrent builds in the same directory don't try to use // the same filename for metadata (stomping over one another) let tmpdir = TempDir::new("rustc").expect("needs a temp dir"); let metadata = tmpdir.path().join(METADATA_FILENAME); match fs::File::create(&metadata).write(trans.metadata) { Ok(..) => {} Err(e) => { sess.err(format!("failed to write {}: {}", metadata.display(), e)); sess.abort_if_errors(); } } a.add_file(&metadata, false); remove(sess, &metadata); // For LTO purposes, the bytecode of this library is also inserted // into the archive. let bc = obj_filename.with_extension("bc"); a.add_file(&bc, false); if !sess.opts.cg.save_temps && !sess.opts.output_types.contains(&OutputTypeBitcode) { remove(sess, &bc); } // After adding all files to the archive, we need to update the // symbol table of the archive. This currently dies on OSX (see // #11162), and isn't necessary there anyway match sess.targ_cfg.os { abi::OsMacos => {} _ => { a.update_symbols(); } } } None => {} } return a; } // Create a static archive // // This is essentially the same thing as an rlib, but it also involves adding // all of the upstream crates' objects into the archive. This will slurp in // all of the native libraries of upstream dependencies as well. // // Additionally, there's no way for us to link dynamic libraries, so we warn // about all dynamic library dependencies that they're not linked in. // // There's no need to include metadata in a static archive, so ensure to not // link in the metadata object file (and also don't prepare the archive with a // metadata file). fn link_staticlib(sess: Session, obj_filename: &Path, out_filename: &Path) { let mut a = link_rlib(sess, None, obj_filename, out_filename); a.add_native_library("morestack").unwrap(); a.add_native_library("compiler-rt").unwrap(); let crates = sess.cstore.get_used_crates(cstore::RequireStatic); for &(cnum, ref path) in crates.iter() { let name = sess.cstore.get_crate_data(cnum).name.clone(); let p = match *path { Some(ref p) => p.clone(), None => { sess.err(format!("could not find rlib for: `{}`", name)); continue } }; a.add_rlib(&p, name, sess.lto()).unwrap(); let native_libs = csearch::get_native_libraries(sess.cstore, cnum); for &(kind, ref lib) in native_libs.iter() { let name = match kind { cstore::NativeStatic => "static library", cstore::NativeUnknown => "library", cstore::NativeFramework => "framework", }; sess.warn(format!("unlinked native {}: {}", name, *lib)); } } } // Create a dynamic library or executable // // This will invoke the system linker/cc to create the resulting file. This // links to all upstream files as well. fn link_natively(sess: Session, dylib: bool, obj_filename: &Path, out_filename: &Path) { let tmpdir = TempDir::new("rustc").expect("needs a temp dir"); // The invocations of cc share some flags across platforms let cc_prog = get_cc_prog(sess); let mut cc_args = sess.targ_cfg.target_strs.cc_args.clone(); cc_args.push_all_move(link_args(sess, dylib, tmpdir.path(), obj_filename, out_filename)); if (sess.opts.debugging_opts & session::PRINT_LINK_ARGS) != 0 { println!("{} link args: '{}'", cc_prog, cc_args.connect("' '")); } // May have not found libraries in the right formats. sess.abort_if_errors(); // Invoke the system linker debug!("{} {}", cc_prog, cc_args.connect(" ")); let prog = time(sess.time_passes(), "running linker", (), |()| run::process_output(cc_prog, cc_args)); match prog { Ok(prog) => { if !prog.status.success() { sess.err(format!("linking with `{}` failed: {}", cc_prog, prog.status)); sess.note(format!("{} arguments: '{}'", cc_prog, cc_args.connect("' '"))); sess.note(str::from_utf8_owned(prog.error + prog.output).unwrap()); sess.abort_if_errors(); } }, Err(e) => { sess.err(format!("could not exec the linker `{}`: {}", cc_prog, e)); sess.abort_if_errors(); } } // On OSX, debuggers need this utility to get run to do some munging of // the symbols if sess.targ_cfg.os == abi::OsMacos && sess.opts.debuginfo { // FIXME (#9639): This needs to handle non-utf8 paths match run::process_status("dsymutil", [out_filename.as_str().unwrap().to_owned()]) { Ok(..) => {} Err(e) => { sess.err(format!("failed to run dsymutil: {}", e)); sess.abort_if_errors(); } } } } fn link_args(sess: Session, dylib: bool, tmpdir: &Path, obj_filename: &Path, out_filename: &Path) -> ~[~str] { // The default library location, we need this to find the runtime. // The location of crates will be determined as needed. // FIXME (#9639): This needs to handle non-utf8 paths let lib_path = sess.filesearch.get_target_lib_path(); let stage: ~str = ~"-L" + lib_path.as_str().unwrap(); let mut args = ~[stage]; // FIXME (#9639): This needs to handle non-utf8 paths args.push_all([ ~"-o", out_filename.as_str().unwrap().to_owned(), obj_filename.as_str().unwrap().to_owned()]); // When linking a dynamic library, we put the metadata into a section of the // executable. This metadata is in a separate object file from the main // object file, so we link that in here. if dylib { let metadata = obj_filename.with_extension("metadata.o"); args.push(metadata.as_str().unwrap().to_owned()); } // We want to prevent the compiler from accidentally leaking in any system // libraries, so we explicitly ask gcc to not link to any libraries by // default. Note that this does not happen for windows because windows pulls // in some large number of libraries and I couldn't quite figure out which // subset we wanted. // // FIXME(#11937) we should invoke the system linker directly if sess.targ_cfg.os != abi::OsWin32 { args.push(~"-nodefaultlibs"); } if sess.targ_cfg.os == abi::OsLinux { // GNU-style linkers will use this to omit linking to libraries which // don't actually fulfill any relocations, but only for libraries which // follow this flag. Thus, use it before specifying libraries to link to. args.push(~"-Wl,--as-needed"); // GNU-style linkers support optimization with -O. --gc-sections // removes metadata and potentially other useful things, so don't // include it. GNU ld doesn't need a numeric argument, but other linkers // do. if sess.opts.optimize == session::Default || sess.opts.optimize == session::Aggressive { args.push(~"-Wl,-O1"); } } if sess.targ_cfg.os == abi::OsWin32 { // Make sure that we link to the dynamic libgcc, otherwise cross-module // DWARF stack unwinding will not work. // This behavior may be overridden by --link-args "-static-libgcc" args.push(~"-shared-libgcc"); } if sess.targ_cfg.os == abi::OsAndroid { // Many of the symbols defined in compiler-rt are also defined in libgcc. // Android linker doesn't like that by default. args.push(~"-Wl,--allow-multiple-definition"); } add_local_native_libraries(&mut args, sess); add_upstream_rust_crates(&mut args, sess, dylib, tmpdir); add_upstream_native_libraries(&mut args, sess); // # Telling the linker what we're doing if dylib { // On mac we need to tell the linker to let this library be rpathed if sess.targ_cfg.os == abi::OsMacos { args.push(~"-dynamiclib"); args.push(~"-Wl,-dylib"); // FIXME (#9639): This needs to handle non-utf8 paths if !sess.opts.cg.no_rpath { args.push(~"-Wl,-install_name,@rpath/" + out_filename.filename_str().unwrap()); } } else { args.push(~"-shared") } } if sess.targ_cfg.os == abi::OsFreebsd { args.push_all([~"-L/usr/local/lib", ~"-L/usr/local/lib/gcc46", ~"-L/usr/local/lib/gcc44"]); } // FIXME (#2397): At some point we want to rpath our guesses as to // where extern libraries might live, based on the // addl_lib_search_paths if !sess.opts.cg.no_rpath { args.push_all(rpath::get_rpath_flags(sess, out_filename)); } // Stack growth requires statically linking a __morestack function args.push(~"-lmorestack"); // compiler-rt contains implementations of low-level LLVM helpers // It should go before platform and user libraries, so it has first dibs // at resolving symbols that also appear in libgcc. args.push(~"-lcompiler-rt"); // Finally add all the linker arguments provided on the command line along // with any #[link_args] attributes found inside the crate args.push_all(sess.opts.cg.link_args); let used_link_args = sess.cstore.get_used_link_args(); let used_link_args = used_link_args.borrow(); for arg in used_link_args.get().iter() { args.push(arg.clone()); } return args; } // # Native library linking // // User-supplied library search paths (-L on the command line). These are // the same paths used to find Rust crates, so some of them may have been // added already by the previous crate linking code. This only allows them // to be found at compile time so it is still entirely up to outside // forces to make sure that library can be found at runtime. // // Also note that the native libraries linked here are only the ones located // in the current crate. Upstream crates with native library dependencies // may have their native library pulled in above. fn add_local_native_libraries(args: &mut ~[~str], sess: Session) { let addl_lib_search_paths = sess.opts.addl_lib_search_paths.borrow(); for path in addl_lib_search_paths.get().iter() { // FIXME (#9639): This needs to handle non-utf8 paths args.push("-L" + path.as_str().unwrap().to_owned()); } let rustpath = filesearch::rust_path(); for path in rustpath.iter() { // FIXME (#9639): This needs to handle non-utf8 paths args.push("-L" + path.as_str().unwrap().to_owned()); } let used_libraries = sess.cstore.get_used_libraries(); let used_libraries = used_libraries.borrow(); for &(ref l, kind) in used_libraries.get().iter() { match kind { cstore::NativeUnknown | cstore::NativeStatic => { args.push("-l" + *l); } cstore::NativeFramework => { args.push(~"-framework"); args.push(l.to_owned()); } } } } // # Rust Crate linking // // Rust crates are not considered at all when creating an rlib output. All // dependencies will be linked when producing the final output (instead of // the intermediate rlib version) fn add_upstream_rust_crates(args: &mut ~[~str], sess: Session, dylib: bool, tmpdir: &Path) { // As a limitation of the current implementation, we require that everything // must be static or everything must be dynamic. The reasons for this are a // little subtle, but as with staticlibs and rlibs, the goal is to prevent // duplicate copies of the same library showing up. For example, a static // immediate dependency might show up as an upstream dynamic dependency and // we currently have no way of knowing that. We know that all dynamic // libraries require dynamic dependencies (see above), so it's satisfactory // to include either all static libraries or all dynamic libraries. // // With this limitation, we expose a compiler default linkage type and an // option to reverse that preference. The current behavior looks like: // // * If a dylib is being created, upstream dependencies must be dylibs // * If nothing else is specified, static linking is preferred // * If the -C prefer-dynamic flag is given, dynamic linking is preferred // * If one form of linking fails, the second is also attempted // * If both forms fail, then we emit an error message let dynamic = get_deps(sess.cstore, cstore::RequireDynamic); let statik = get_deps(sess.cstore, cstore::RequireStatic); match (dynamic, statik, sess.opts.cg.prefer_dynamic, dylib) { (_, Some(deps), false, false) => { add_static_crates(args, sess, tmpdir, deps) } (None, Some(deps), true, false) => { // If you opted in to dynamic linking and we decided to emit a // static output, you should probably be notified of such an event! sess.warn("dynamic linking was preferred, but dependencies \ could not all be found in an dylib format."); sess.warn("linking statically instead, using rlibs"); add_static_crates(args, sess, tmpdir, deps) } (Some(deps), _, _, _) => add_dynamic_crates(args, sess, deps), (None, _, _, true) => { sess.err("dylib output requested, but some depenencies could not \ be found in the dylib format"); let deps = sess.cstore.get_used_crates(cstore::RequireDynamic); for (cnum, path) in deps.move_iter() { if path.is_some() { continue } let name = sess.cstore.get_crate_data(cnum).name.clone(); sess.note(format!("dylib not found: {}", name)); } } (None, None, pref, false) => { let (pref, name) = if pref { sess.err("dynamic linking is preferred, but dependencies were \ not found in either dylib or rlib format"); (cstore::RequireDynamic, "dylib") } else { sess.err("dependencies were not all found in either dylib or \ rlib format"); (cstore::RequireStatic, "rlib") }; sess.note(format!("dependencies not found in the `{}` format", name)); for (cnum, path) in sess.cstore.get_used_crates(pref).move_iter() { if path.is_some() { continue } let name = sess.cstore.get_crate_data(cnum).name.clone(); sess.note(name); } } } // Converts a library file-stem into a cc -l argument fn unlib(config: @session::Config, stem: &str) -> ~str { if stem.starts_with("lib") && config.os != abi::OsWin32 { stem.slice(3, stem.len()).to_owned() } else { stem.to_owned() } } // Attempts to find all dependencies with a certain linkage preference, // returning `None` if not all libraries could be found with that // preference. fn get_deps(cstore: &cstore::CStore, preference: cstore::LinkagePreference) -> Option<~[(ast::CrateNum, Path)]> { let crates = cstore.get_used_crates(preference); if crates.iter().all(|&(_, ref p)| p.is_some()) { Some(crates.move_iter().map(|(a, b)| (a, b.unwrap())).collect()) } else { None } } // Adds the static "rlib" versions of all crates to the command line. fn add_static_crates(args: &mut ~[~str], sess: Session, tmpdir: &Path, crates: ~[(ast::CrateNum, Path)]) { for (cnum, cratepath) in crates.move_iter() { // When performing LTO on an executable output, all of the // bytecode from the upstream libraries has already been // included in our object file output. We need to modify all of // the upstream archives to remove their corresponding object // file to make sure we don't pull the same code in twice. // // We must continue to link to the upstream archives to be sure // to pull in native static dependencies. As the final caveat, // on linux it is apparently illegal to link to a blank archive, // so if an archive no longer has any object files in it after // we remove `lib.o`, then don't link against it at all. // // If we're not doing LTO, then our job is simply to just link // against the archive. if sess.lto() { let name = sess.cstore.get_crate_data(cnum).name.clone(); time(sess.time_passes(), format!("altering {}.rlib", name), (), |()| { let dst = tmpdir.join(cratepath.filename().unwrap()); match fs::copy(&cratepath, &dst) { Ok(..) => {} Err(e) => { sess.err(format!("failed to copy {} to {}: {}", cratepath.display(), dst.display(), e)); sess.abort_if_errors(); } } let dst_str = dst.as_str().unwrap().to_owned(); let mut archive = Archive::open(sess, dst); archive.remove_file(format!("{}.o", name)); let files = archive.files(); if files.iter().any(|s| s.ends_with(".o")) { args.push(dst_str); } }); } else { args.push(cratepath.as_str().unwrap().to_owned()); } } } // Same thing as above, but for dynamic crates instead of static crates. fn add_dynamic_crates(args: &mut ~[~str], sess: Session, crates: ~[(ast::CrateNum, Path)]) { // If we're performing LTO, then it should have been previously required // that all upstream rust dependencies were available in an rlib format. assert!(!sess.lto()); for (_, cratepath) in crates.move_iter() { // Just need to tell the linker about where the library lives and // what its name is let dir = cratepath.dirname_str().unwrap(); if !dir.is_empty() { args.push("-L" + dir); } let libarg = unlib(sess.targ_cfg, cratepath.filestem_str().unwrap()); args.push("-l" + libarg); } } } // Link in all of our upstream crates' native dependencies. Remember that // all of these upstream native depenencies are all non-static // dependencies. We've got two cases then: // // 1. The upstream crate is an rlib. In this case we *must* link in the // native dependency because the rlib is just an archive. // // 2. The upstream crate is a dylib. In order to use the dylib, we have to // have the dependency present on the system somewhere. Thus, we don't // gain a whole lot from not linking in the dynamic dependency to this // crate as well. // // The use case for this is a little subtle. In theory the native // dependencies of a crate a purely an implementation detail of the crate // itself, but the problem arises with generic and inlined functions. If a // generic function calls a native function, then the generic function must // be instantiated in the target crate, meaning that the native symbol must // also be resolved in the target crate. fn add_upstream_native_libraries(args: &mut ~[~str], sess: Session) { let cstore = sess.cstore; cstore.iter_crate_data(|cnum, _| { let libs = csearch::get_native_libraries(cstore, cnum); for &(kind, ref lib) in libs.iter() { match kind { cstore::NativeUnknown => args.push("-l" + *lib), cstore::NativeFramework => { args.push(~"-framework"); args.push(lib.to_owned()); } cstore::NativeStatic => { sess.bug("statics shouldn't be propagated"); } } } }); }