// 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 super::archive::{Archive, ArchiveBuilder, ArchiveConfig, METADATA_FILENAME}; use super::archive; use super::rpath; use super::rpath::RPathConfig; use super::svh::Svh; use driver::driver::{CrateTranslation, OutputFilenames, Input, FileInput}; use driver::config::NoDebugInfo; use driver::session::Session; use driver::config; use llvm; use llvm::ModuleRef; use metadata::common::LinkMeta; use metadata::{encoder, cstore, filesearch, csearch, loader, creader}; 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, CString}; use std::char; use std::collections::HashSet; use std::io::{fs, TempDir, Command}; use std::io; use std::mem; use std::ptr; use std::str; use std::string::String; use flate; use serialize::hex::ToHex; use syntax::abi; use syntax::ast; use syntax::ast_map::{PathElem, PathElems, PathName}; use syntax::ast_map; use syntax::attr::AttrMetaMethods; use syntax::codemap::Span; use syntax::parse::token; // RLIB LLVM-BYTECODE OBJECT LAYOUT // Version 1 // Bytes Data // 0..10 "RUST_OBJECT" encoded in ASCII // 11..14 format version as little-endian u32 // 15..22 size in bytes of deflate compressed LLVM bitcode as // little-endian u64 // 23.. compressed LLVM bitcode // This is the "magic number" expected at the beginning of a LLVM bytecode // object in an rlib. pub static RLIB_BYTECODE_OBJECT_MAGIC: &'static [u8] = b"RUST_OBJECT"; // The version number this compiler will write to bytecode objects in rlibs pub static RLIB_BYTECODE_OBJECT_VERSION: u32 = 1; // The offset in bytes the bytecode object format version number can be found at pub static RLIB_BYTECODE_OBJECT_VERSION_OFFSET: uint = 11; // The offset in bytes the size of the compressed bytecode can be found at in // format version 1 pub static RLIB_BYTECODE_OBJECT_V1_DATASIZE_OFFSET: uint = RLIB_BYTECODE_OBJECT_VERSION_OFFSET + 4; // The offset in bytes the compressed LLVM bytecode can be found at in format // version 1 pub static RLIB_BYTECODE_OBJECT_V1_DATA_OFFSET: uint = RLIB_BYTECODE_OBJECT_V1_DATASIZE_OFFSET + 8; #[deriving(Clone, PartialEq, PartialOrd, Ord, Eq)] pub enum OutputType { OutputTypeBitcode, OutputTypeAssembly, OutputTypeLlvmAssembly, OutputTypeObject, OutputTypeExe, } pub fn llvm_err(sess: &Session, msg: String) -> ! { unsafe { let cstr = llvm::LLVMRustGetLastError(); if cstr == ptr::null() { sess.fatal(msg.as_slice()); } else { let err = CString::new(cstr, true); let err = String::from_utf8_lossy(err.as_bytes()); sess.fatal(format!("{}: {}", msg.as_slice(), err.as_slice()).as_slice()); } } } pub fn write_output_file( sess: &Session, target: llvm::TargetMachineRef, pm: llvm::PassManagerRef, m: ModuleRef, output: &Path, file_type: llvm::FileType) { unsafe { output.with_c_str(|output| { let result = llvm::LLVMRustWriteOutputFile( target, pm, m, output, file_type); if !result { llvm_err(sess, "could not write output".to_string()); } }) } } pub mod write { use super::super::lto; use super::{write_output_file, OutputType}; use super::{OutputTypeAssembly, OutputTypeBitcode}; use super::{OutputTypeExe, OutputTypeLlvmAssembly}; use super::{OutputTypeObject}; use driver::driver::{CrateTranslation, OutputFilenames}; use driver::config::NoDebugInfo; use driver::session::Session; use driver::config; use llvm; use llvm::{ModuleRef, TargetMachineRef, PassManagerRef}; use util::common::time; use syntax::abi; use std::c_str::ToCStr; use std::io::{Command}; use libc::{c_uint, c_int}; 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. // // On iOS only armv7 and newer are supported. So it is useful to // get all hardware potential via VFP3 (hardware floating point) // and NEON (SIMD) instructions supported by LLVM. // Note that without those flags various linking errors might // arise as some of intrinsics are converted into function calls // and nobody provides implementations those functions fn target_feature<'a>(sess: &'a Session) -> &'a str { match sess.targ_cfg.os { abi::OsAndroid => { if "" == sess.opts.cg.target_feature.as_slice() { "+v7" } else { sess.opts.cg.target_feature.as_slice() } }, abi::OsiOS if sess.targ_cfg.arch == abi::Arm => { "+v7,+thumb2,+vfp3,+neon" }, _ => 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 opt_level = match sess.opts.optimize { config::No => llvm::CodeGenLevelNone, config::Less => llvm::CodeGenLevelLess, config::Default => llvm::CodeGenLevelDefault, config::Aggressive => 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 != NoDebugInfo) || (sess.targ_cfg.os == abi::OsMacos && sess.targ_cfg.arch == abi::X86_64); // OSX has -dead_strip, which doesn't rely on ffunction_sections // FIXME(#13846) this should be enabled for windows let ffunction_sections = sess.targ_cfg.os != abi::OsMacos && sess.targ_cfg.os != abi::OsWindows; let fdata_sections = ffunction_sections; let reloc_model = match sess.opts.cg.relocation_model.as_slice() { "pic" => llvm::RelocPIC, "static" => llvm::RelocStatic, "default" => llvm::RelocDefault, "dynamic-no-pic" => llvm::RelocDynamicNoPic, _ => { sess.err(format!("{} is not a valid relocation mode", sess.opts .cg .relocation_model).as_slice()); sess.abort_if_errors(); return; } }; let code_model = match sess.opts.cg.code_model.as_slice() { "default" => llvm::CodeModelDefault, "small" => llvm::CodeModelSmall, "kernel" => llvm::CodeModelKernel, "medium" => llvm::CodeModelMedium, "large" => llvm::CodeModelLarge, _ => { sess.err(format!("{} is not a valid code model", sess.opts .cg .code_model).as_slice()); sess.abort_if_errors(); return; } }; let tm = sess.targ_cfg .target_strs .target_triple .as_slice() .with_c_str(|t| { sess.opts.cg.target_cpu.as_slice().with_c_str(|cpu| { target_feature(sess).with_c_str(|features| { llvm::LLVMRustCreateTargetMachine( t, cpu, features, code_model, reloc_model, opt_level, true /* EnableSegstk */, use_softfp, no_fp_elim, ffunction_sections, fdata_sections, ) }) }) }); // 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.as_slice().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, opt_level, trans.no_builtins); } for pass in sess.opts.cg.passes.iter() { pass.as_slice().with_c_str(|s| { if !llvm::LLVMRustAddPass(mpm, s) { sess.warn(format!("unknown pass {}, ignoring", *pass).as_slice()); } }) } // 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. if sess.opts.cg.save_temps || (sess.crate_types.borrow().contains(&config::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.as_slice())); 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, no_builtins: bool, f: |PassManagerRef|) { unsafe { let cpm = llvm::LLVMCreatePassManager(); llvm::LLVMRustAddAnalysisPasses(tm, cpm, llmod); llvm::LLVMRustAddLibraryInfo(cpm, llmod, no_builtins); 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, trans.no_builtins, |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, trans.no_builtins, |cpm| { write_output_file(sess, tm, cpm, llmod, &path, 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, trans.no_builtins, |cpm| { write_output_file(sess, tm, cpm, llmod, path, llvm::ObjectFile); }); } None => {} } if needs_metadata { with_codegen(tm, trans.metadata_module, trans.no_builtins, |cpm| { let out = output.temp_path(OutputTypeObject) .with_extension("metadata.o"); write_output_file(sess, tm, cpm, trans.metadata_module, &out, 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 pname = super::get_cc_prog(sess); let mut cmd = Command::new(pname.as_slice()); cmd.arg("-c").arg("-o").arg(outputs.path(OutputTypeObject)) .arg(outputs.temp_path(OutputTypeAssembly)); debug!("{}", &cmd); match cmd.output() { Ok(prog) => { if !prog.status.success() { sess.err(format!("linking with `{}` failed: {}", pname, prog.status).as_slice()); sess.note(format!("{}", &cmd).as_slice()); let mut note = prog.error.clone(); note.push_all(prog.output.as_slice()); sess.note(str::from_utf8(note.as_slice()).unwrap()); sess.abort_if_errors(); } }, Err(e) => { sess.err(format!("could not exec the linker `{}`: {}", pname, e).as_slice()); sess.abort_if_errors(); } } } unsafe fn configure_llvm(sess: &Session) { use std::sync::{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 == config::Default || sess.opts.optimize == config::Aggressive); let vectorize_slp = !sess.opts.cg.no_vectorize_slp && sess.opts.optimize == config::Aggressive; let mut llvm_c_strs = Vec::new(); let mut llvm_args = Vec::new(); { let add = |arg: &str| { let s = arg.to_c_str(); llvm_args.push(s.as_ptr()); 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).as_slice()); } } 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: llvm::PassManagerRef, mpm: llvm::PassManagerRef, llmod: ModuleRef, opt: llvm::CodeGenOptLevel, no_builtins: bool) { // 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 { llvm::CodeGenLevelNone => { // Don't add lifetime intrinsics at O0 llvm::LLVMRustAddAlwaysInlinePass(builder, false); } llvm::CodeGenLevelLess => { llvm::LLVMRustAddAlwaysInlinePass(builder, true); } // numeric values copied from clang llvm::CodeGenLevelDefault => { llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225); } llvm::CodeGenLevelAggressive => { llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275); } } llvm::LLVMPassManagerBuilderSetOptLevel(builder, opt as c_uint); llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, no_builtins); // Use the builder to populate the function/module pass managers. llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(builder, fpm); llvm::LLVMPassManagerBuilderPopulateModulePassManager(builder, mpm); llvm::LLVMPassManagerBuilderDispose(builder); match opt { llvm::CodeGenLevelDefault | llvm::CodeGenLevelAggressive => { "mergefunc".with_c_str(|s| llvm::LLVMRustAddPass(mpm, s)); } _ => {} }; } } /* * 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 find_crate_name(sess: Option<&Session>, attrs: &[ast::Attribute], input: &Input) -> String { use syntax::crateid::CrateId; let validate = |s: String, span: Option| { creader::validate_crate_name(sess, s.as_slice(), span); s }; // Look in attributes 100% of the time to make sure the attribute is marked // as used. After doing this, however, we still prioritize a crate name from // the command line over one found in the #[crate_name] attribute. If we // find both we ensure that they're the same later on as well. let attr_crate_name = attrs.iter().find(|at| at.check_name("crate_name")) .and_then(|at| at.value_str().map(|s| (at, s))); match sess { Some(sess) => { match sess.opts.crate_name { Some(ref s) => { match attr_crate_name { Some((attr, ref name)) if s.as_slice() != name.get() => { let msg = format!("--crate-name and #[crate_name] \ are required to match, but `{}` \ != `{}`", s, name); sess.span_err(attr.span, msg.as_slice()); } _ => {}, } return validate(s.clone(), None); } None => {} } } None => {} } match attr_crate_name { Some((attr, s)) => return validate(s.get().to_string(), Some(attr.span)), None => {} } let crate_id = attrs.iter().find(|at| at.check_name("crate_id")) .and_then(|at| at.value_str().map(|s| (at, s))) .and_then(|(at, s)| { from_str::(s.get()).map(|id| (at, id)) }); match crate_id { Some((attr, id)) => { match sess { Some(sess) => { sess.span_warn(attr.span, "the #[crate_id] attribute is \ deprecated for the \ #[crate_name] attribute"); } None => {} } return validate(id.name, Some(attr.span)) } None => {} } match *input { FileInput(ref path) => { match path.filestem_str() { Some(s) => return validate(s.to_string(), None), None => {} } } _ => {} } "rust-out".to_string() } pub fn build_link_meta(sess: &Session, krate: &ast::Crate, name: String) -> LinkMeta { let r = LinkMeta { crate_name: name, crate_hash: Svh::calculate(&sess.opts.cg.metadata, krate), }; info!("{}", r); return r; } fn truncated_hash_result(symbol_hasher: &mut Sha256) -> String { let output = symbol_hasher.result_bytes(); // 64 bits should be enough to avoid collisions. output.slice_to(8).to_hex().to_string() } // 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) -> String { // 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.crate_name.as_slice()); symbol_hasher.input_str("-"); symbol_hasher.input_str(link_meta.crate_hash.as_str()); for meta in tcx.sess.crate_metadata.borrow().iter() { symbol_hasher.input_str(meta.as_slice()); } symbol_hasher.input_str("-"); symbol_hasher.input_str(encoder::encoded_ty(tcx, t).as_slice()); // Prefix with 'h' so that it never blends into adjacent digits let mut hash = String::from_str("h"); hash.push_str(truncated_hash_result(symbol_hasher).as_slice()); hash } fn get_symbol_hash(ccx: &CrateContext, t: ty::t) -> String { match ccx.type_hashcodes.borrow().find(&t) { Some(h) => return h.to_string(), None => {} } let mut symbol_hasher = ccx.symbol_hasher.borrow_mut(); let hash = symbol_hash(ccx.tcx(), &mut *symbol_hasher, t, &ccx.link_meta); ccx.type_hashcodes.borrow_mut().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) -> String { let mut result = String::new(); 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' | '_' | '.' | '$' => result.push_char(c), _ => { let mut tstr = String::new(); char::escape_unicode(c, |c| tstr.push_char(c)); result.push_char('$'); result.push_str(tstr.as_slice().slice_from(1)); } } } // Underscore-qualify anything that didn't start as an ident. if result.len() > 0u && result.as_bytes()[0] != '_' as u8 && ! char::is_XID_start(result.as_bytes()[0] as char) { return format!("_{}", result.as_slice()); } return result; } pub fn mangle>(mut path: PI, hash: Option<&str>) -> String { // 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 = String::from_str("_ZN"); // _Z == Begin name-sequence, N == nested fn push(n: &mut String, s: &str) { let sani = sanitize(s); n.push_str(format!("{}{}", sani.len(), sani).as_slice()); } // 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 => {} } n.push_char('E'); // End name-sequence. n } pub fn exported_name(path: PathElems, hash: &str) -> String { mangle(path, Some(hash)) } pub fn mangle_exported_name(ccx: &CrateContext, path: PathElems, t: ty::t, id: ast::NodeId) -> String { 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.as_bytes()[extra1] as char); hash.push_char(EXTRA_CHARS.as_bytes()[extra2] as char); hash.push_char(EXTRA_CHARS.as_bytes()[extra3] as char); exported_name(path, hash.as_slice()) } pub fn mangle_internal_name_by_type_and_seq(ccx: &CrateContext, t: ty::t, name: &str) -> String { let s = ppaux::ty_to_string(ccx.tcx(), t); let path = [PathName(token::intern(s.as_slice())), gensym_name(name)]; let hash = get_symbol_hash(ccx, t); mangle(ast_map::Values(path.iter()), Some(hash.as_slice())) } pub fn mangle_internal_name_by_path_and_seq(path: PathElems, flav: &str) -> String { mangle(path.chain(Some(gensym_name(flav)).move_iter()), None) } pub fn get_cc_prog(sess: &Session) -> String { match sess.opts.cg.linker { Some(ref linker) => return linker.to_string(), 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 Windows, there is no cc command, so we add a condition to make it use gcc. match sess.targ_cfg.os { abi::OsWindows => "gcc", _ => "cc", }.to_string() } pub fn get_ar_prog(sess: &Session) -> String { match sess.opts.cg.ar { Some(ref ar) => (*ar).clone(), None => "ar".to_string() } } fn remove(sess: &Session, path: &Path) { match fs::unlink(path) { Ok(..) => {} Err(e) => { sess.err(format!("failed to remove {}: {}", path.display(), e).as_slice()); } } } /// 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, crate_name: &str) -> Vec { let mut out_filenames = Vec::new(); for &crate_type in sess.crate_types.borrow().iter() { if invalid_output_for_target(sess, crate_type) { sess.bug(format!("invalid output type `{}` for target os `{}`", crate_type, sess.targ_cfg.os).as_slice()); } let out_file = link_binary_output(sess, trans, crate_type, outputs, crate_name); 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 } /// Returns default crate type for target /// /// Default crate type is used when crate type isn't provided neither /// through cmd line arguments nor through crate attributes /// /// It is CrateTypeExecutable for all platforms but iOS as there is no /// way to run iOS binaries anyway without jailbreaking and /// interaction with Rust code through static library is the only /// option for now pub fn default_output_for_target(sess: &Session) -> config::CrateType { match sess.targ_cfg.os { abi::OsiOS => config::CrateTypeStaticlib, _ => config::CrateTypeExecutable } } /// Checks if target supports crate_type as output pub fn invalid_output_for_target(sess: &Session, crate_type: config::CrateType) -> bool { match (sess.targ_cfg.os, crate_type) { (abi::OsiOS, config::CrateTypeDylib) => true, _ => false } } 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: config::CrateType, name: &str, out_filename: &Path) -> Path { let libname = format!("{}{}", name, sess.opts.cg.extra_filename); match crate_type { config::CrateTypeRlib => { out_filename.with_filename(format!("lib{}.rlib", libname)) } config::CrateTypeDylib => { let (prefix, suffix) = match sess.targ_cfg.os { abi::OsWindows => (loader::WIN32_DLL_PREFIX, loader::WIN32_DLL_SUFFIX), abi::OsMacos => (loader::MACOS_DLL_PREFIX, loader::MACOS_DLL_SUFFIX), abi::OsLinux => (loader::LINUX_DLL_PREFIX, loader::LINUX_DLL_SUFFIX), abi::OsAndroid => (loader::ANDROID_DLL_PREFIX, loader::ANDROID_DLL_SUFFIX), abi::OsFreebsd => (loader::FREEBSD_DLL_PREFIX, loader::FREEBSD_DLL_SUFFIX), abi::OsDragonfly => (loader::DRAGONFLY_DLL_PREFIX, loader::DRAGONFLY_DLL_SUFFIX), abi::OsiOS => unreachable!(), }; out_filename.with_filename(format!("{}{}{}", prefix, libname, suffix)) } config::CrateTypeStaticlib => { out_filename.with_filename(format!("lib{}.a", libname)) } config::CrateTypeExecutable => { match sess.targ_cfg.os { abi::OsWindows => out_filename.with_extension("exe"), abi::OsMacos | abi::OsLinux | abi::OsAndroid | abi::OsFreebsd | abi::OsDragonfly | abi::OsiOS => out_filename.clone(), } } } } fn link_binary_output(sess: &Session, trans: &CrateTranslation, crate_type: config::CrateType, outputs: &OutputFilenames, crate_name: &str) -> 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, crate_name, &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()).as_slice()); } else if !obj_is_writeable { sess.fatal(format!("object file {} is not writeable -- check its \ permissions.", obj_filename.display()).as_slice()); } match crate_type { config::CrateTypeRlib => { link_rlib(sess, Some(trans), &obj_filename, &out_filename).build(); } config::CrateTypeStaticlib => { link_staticlib(sess, &obj_filename, &out_filename); } config::CrateTypeExecutable => { link_natively(sess, trans, false, &obj_filename, &out_filename); } config::CrateTypeDylib => { link_natively(sess, trans, true, &obj_filename, &out_filename); } } out_filename } fn archive_search_paths(sess: &Session) -> Vec { let mut rustpath = filesearch::rust_path(); rustpath.push(sess.target_filesearch().get_lib_path()); // FIXME: Addl lib search paths are an unordered HashSet? // Shouldn't this search be done in some order? let addl_lib_paths: HashSet = sess.opts.addl_lib_search_paths.borrow().clone(); let mut search: Vec = addl_lib_paths.move_iter().collect(); search.push_all(rustpath.as_slice()); return search; } // 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<'a>(sess: &'a Session, trans: Option<&CrateTranslation>, // None == no metadata/bytecode obj_filename: &Path, out_filename: &Path) -> ArchiveBuilder<'a> { let handler = &sess.diagnostic().handler; let config = ArchiveConfig { handler: handler, dst: out_filename.clone(), lib_search_paths: archive_search_paths(sess), os: sess.targ_cfg.os, maybe_ar_prog: sess.opts.cg.ar.clone() }; let mut ab = ArchiveBuilder::create(config); ab.add_file(obj_filename).unwrap(); for &(ref l, kind) in sess.cstore.get_used_libraries().borrow().iter() { match kind { cstore::NativeStatic => { ab.add_native_library(l.as_slice()).unwrap(); } cstore::NativeFramework | cstore::NativeUnknown => {} } } // After adding all files to the archive, we need to update the // symbol table of the archive. ab.update_symbols(); let mut ab = match sess.targ_cfg.os { // For OSX/iOS, we must be careful to update symbols only when adding // object files. We're about to start adding non-object files, so run // `ar` now to process the object files. abi::OsMacos | abi::OsiOS => ab.build().extend(), _ => ab, }; // 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 .as_slice()) { Ok(..) => {} Err(e) => { sess.err(format!("failed to write {}: {}", metadata.display(), e).as_slice()); sess.abort_if_errors(); } } ab.add_file(&metadata).unwrap(); remove(sess, &metadata); // For LTO purposes, the bytecode of this library is also inserted // into the archive. // // Note that we make sure that the bytecode filename in the archive // is never exactly 16 bytes long by adding a 16 byte extension to // it. This is to work around a bug in LLDB that would cause it to // crash if the name of a file in an archive was exactly 16 bytes. let bc_filename = obj_filename.with_extension("bc"); let bc_deflated_filename = obj_filename.with_extension("bytecode.deflate"); let bc_data = match fs::File::open(&bc_filename).read_to_end() { Ok(buffer) => buffer, Err(e) => sess.fatal(format!("failed to read bytecode: {}", e).as_slice()) }; let bc_data_deflated = match flate::deflate_bytes(bc_data.as_slice()) { Some(compressed) => compressed, None => sess.fatal(format!("failed to compress bytecode from {}", bc_filename.display()).as_slice()) }; let mut bc_file_deflated = match fs::File::create(&bc_deflated_filename) { Ok(file) => file, Err(e) => { sess.fatal(format!("failed to create compressed bytecode \ file: {}", e).as_slice()) } }; match write_rlib_bytecode_object_v1(&mut bc_file_deflated, bc_data_deflated.as_slice()) { Ok(()) => {} Err(e) => { sess.err(format!("failed to write compressed bytecode: \ {}", e).as_slice()); sess.abort_if_errors() } }; ab.add_file(&bc_deflated_filename).unwrap(); remove(sess, &bc_deflated_filename); if !sess.opts.cg.save_temps && !sess.opts.output_types.contains(&OutputTypeBitcode) { remove(sess, &bc_filename); } } None => {} } ab } fn write_rlib_bytecode_object_v1(writer: &mut T, bc_data_deflated: &[u8]) -> ::std::io::IoResult<()> { let bc_data_deflated_size: u64 = bc_data_deflated.as_slice().len() as u64; try! { writer.write(RLIB_BYTECODE_OBJECT_MAGIC) }; try! { writer.write_le_u32(1) }; try! { writer.write_le_u64(bc_data_deflated_size) }; try! { writer.write(bc_data_deflated.as_slice()) }; let number_of_bytes_written_so_far = RLIB_BYTECODE_OBJECT_MAGIC.len() + // magic id mem::size_of_val(&RLIB_BYTECODE_OBJECT_VERSION) + // version mem::size_of_val(&bc_data_deflated_size) + // data size field bc_data_deflated_size as uint; // actual data // If the number of bytes written to the object so far is odd, add a // padding byte to make it even. This works around a crash bug in LLDB // (see issue #15950) if number_of_bytes_written_so_far % 2 == 1 { try! { writer.write_u8(0) }; } return Ok(()); } // 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 ab = link_rlib(sess, None, obj_filename, out_filename); let mut ab = match sess.targ_cfg.os { abi::OsMacos | abi::OsiOS => ab.build().extend(), _ => ab, }; ab.add_native_library("morestack").unwrap(); ab.add_native_library("compiler-rt").unwrap(); let crates = sess.cstore.get_used_crates(cstore::RequireStatic); let mut all_native_libs = vec![]; 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).as_slice()); continue } }; ab.add_rlib(&p, name.as_slice(), sess.lto()).unwrap(); let native_libs = csearch::get_native_libraries(&sess.cstore, cnum); all_native_libs.extend(native_libs.move_iter()); } ab.update_symbols(); let _ = ab.build(); if !all_native_libs.is_empty() { sess.warn("link against the following native artifacts when linking against \ this static library"); sess.note("the order and any duplication can be significant on some platforms, \ and so may need to be preserved"); } for &(kind, ref lib) in all_native_libs.iter() { let name = match kind { cstore::NativeStatic => "static library", cstore::NativeUnknown => "library", cstore::NativeFramework => "framework", }; sess.note(format!("{}: {}", name, *lib).as_slice()); } } // 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, trans: &CrateTranslation, 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 pname = get_cc_prog(sess); let mut cmd = Command::new(pname.as_slice()); cmd.args(sess.targ_cfg.target_strs.cc_args.as_slice()); link_args(&mut cmd, sess, dylib, tmpdir.path(), trans, obj_filename, out_filename); if (sess.opts.debugging_opts & config::PRINT_LINK_ARGS) != 0 { println!("{}", &cmd); } // May have not found libraries in the right formats. sess.abort_if_errors(); // Invoke the system linker debug!("{}", &cmd); let prog = time(sess.time_passes(), "running linker", (), |()| cmd.output()); match prog { Ok(prog) => { if !prog.status.success() { sess.err(format!("linking with `{}` failed: {}", pname, prog.status).as_slice()); sess.note(format!("{}", &cmd).as_slice()); let mut output = prog.error.clone(); output.push_all(prog.output.as_slice()); sess.note(str::from_utf8(output.as_slice()).unwrap()); sess.abort_if_errors(); } }, Err(e) => { sess.err(format!("could not exec the linker `{}`: {}", pname, e).as_slice()); 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.targ_cfg.os == abi::OsiOS) && (sess.opts.debuginfo != NoDebugInfo) { match Command::new("dsymutil").arg(out_filename).output() { Ok(..) => {} Err(e) => { sess.err(format!("failed to run dsymutil: {}", e).as_slice()); sess.abort_if_errors(); } } } } fn link_args(cmd: &mut Command, sess: &Session, dylib: bool, tmpdir: &Path, trans: &CrateTranslation, obj_filename: &Path, out_filename: &Path) { // The default library location, we need this to find the runtime. // The location of crates will be determined as needed. let lib_path = sess.target_filesearch().get_lib_path(); cmd.arg("-L").arg(&lib_path); cmd.arg("-o").arg(out_filename).arg(obj_filename); // Stack growth requires statically linking a __morestack function. Note // that this is listed *before* all other libraries. Due to the usage of the // --as-needed flag below, the standard library may only be useful for its // rust_stack_exhausted function. In this case, we must ensure that the // libmorestack.a file appears *before* the standard library (so we put it // at the very front). // // Most of the time this is sufficient, except for when LLVM gets super // clever. If, for example, we have a main function `fn main() {}`, LLVM // will optimize out calls to `__morestack` entirely because the function // doesn't need any stack at all! // // To get around this snag, we specially tell the linker to always include // all contents of this library. This way we're guaranteed that the linker // will include the __morestack symbol 100% of the time, always resolving // references to it even if the object above didn't use it. match sess.targ_cfg.os { abi::OsMacos | abi::OsiOS => { let morestack = lib_path.join("libmorestack.a"); let mut v = b"-Wl,-force_load,".to_vec(); v.push_all(morestack.as_vec()); cmd.arg(v.as_slice()); } _ => { cmd.args(["-Wl,--whole-archive", "-lmorestack", "-Wl,--no-whole-archive"]); } } // 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 { cmd.arg(obj_filename.with_extension("metadata.o")); } // 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::OsWindows { cmd.arg("-nodefaultlibs"); } // If we're building a dylib, we don't use --gc-sections because LLVM has // already done the best it can do, and we also don't want to eliminate the // metadata. If we're building an executable, however, --gc-sections drops // the size of hello world from 1.8MB to 597K, a 67% reduction. if !dylib && sess.targ_cfg.os != abi::OsMacos && sess.targ_cfg.os != abi::OsiOS { cmd.arg("-Wl,--gc-sections"); } let used_link_args = sess.cstore.get_used_link_args().borrow(); // Dynamically linked executables can be compiled as position independent if the default // relocation model of position independent code is not changed. This is a requirement to take // advantage of ASLR, as otherwise the functions in the executable are not randomized and can // be used during an exploit of a vulnerability in any code. if sess.targ_cfg.os == abi::OsLinux { let mut args = sess.opts.cg.link_args.iter().chain(used_link_args.iter()); if !dylib && sess.opts.cg.relocation_model.as_slice() == "pic" && !args.any(|x| x.as_slice() == "-static") { cmd.arg("-pie"); } } if sess.targ_cfg.os == abi::OsLinux || sess.targ_cfg.os == abi::OsDragonfly { // 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. cmd.arg("-Wl,--as-needed"); // GNU-style linkers support optimization with -O. GNU ld doesn't need a // numeric argument, but other linkers do. if sess.opts.optimize == config::Default || sess.opts.optimize == config::Aggressive { cmd.arg("-Wl,-O1"); } } else if sess.targ_cfg.os == abi::OsMacos || sess.targ_cfg.os == abi::OsiOS { // The dead_strip option to the linker specifies that functions and data // unreachable by the entry point will be removed. This is quite useful // with Rust's compilation model of compiling libraries at a time into // one object file. For example, this brings hello world from 1.7MB to // 458K. // // Note that this is done for both executables and dynamic libraries. We // won't get much benefit from dylibs because LLVM will have already // stripped away as much as it could. This has not been seen to impact // link times negatively. cmd.arg("-Wl,-dead_strip"); } if sess.targ_cfg.os == abi::OsWindows { // 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" cmd.arg("-shared-libgcc"); // And here, we see obscure linker flags #45. On windows, it has been // found to be necessary to have this flag to compile liblibc. // // First a bit of background. On Windows, the file format is not ELF, // but COFF (at least according to LLVM). COFF doesn't officially allow // for section names over 8 characters, apparently. Our metadata // section, ".note.rustc", you'll note is over 8 characters. // // On more recent versions of gcc on mingw, apparently the section name // is *not* truncated, but rather stored elsewhere in a separate lookup // table. On older versions of gcc, they apparently always truncated the // section names (at least in some cases). Truncating the section name // actually creates "invalid" objects [1] [2], but only for some // introspection tools, not in terms of whether it can be loaded. // // Long story short, passing this flag forces the linker to *not* // truncate section names (so we can find the metadata section after // it's compiled). The real kicker is that rust compiled just fine on // windows for quite a long time *without* this flag, so I have no idea // why it suddenly started failing for liblibc. Regardless, we // definitely don't want section name truncation, so we're keeping this // flag for windows. // // [1] - https://sourceware.org/bugzilla/show_bug.cgi?id=13130 // [2] - https://code.google.com/p/go/issues/detail?id=2139 cmd.arg("-Wl,--enable-long-section-names"); // Always enable DEP (NX bit) when it is available cmd.arg("-Wl,--nxcompat"); // Mark all dynamic libraries and executables as compatible with ASLR cmd.arg("-Wl,--dynamicbase"); } 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. cmd.arg("-Wl,--allow-multiple-definition"); } // Take careful note of the ordering of the arguments we pass to the linker // here. Linkers will assume that things on the left depend on things to the // right. Things on the right cannot depend on things on the left. This is // all formally implemented in terms of resolving symbols (libs on the right // resolve unknown symbols of libs on the left, but not vice versa). // // For this reason, we have organized the arguments we pass to the linker as // such: // // 1. The local object that LLVM just generated // 2. Upstream rust libraries // 3. Local native libraries // 4. Upstream native libraries // // This is generally fairly natural, but some may expect 2 and 3 to be // swapped. The reason that all native libraries are put last is that it's // not recommended for a native library to depend on a symbol from a rust // crate. If this is the case then a staticlib crate is recommended, solving // the problem. // // Additionally, it is occasionally the case that upstream rust libraries // depend on a local native library. In the case of libraries such as // lua/glfw/etc the name of the library isn't the same across all platforms, // so only the consumer crate of a library knows the actual name. This means // that downstream crates will provide the #[link] attribute which upstream // crates will depend on. Hence local native libraries are after out // upstream rust crates. // // In theory this means that a symbol in an upstream native library will be // shadowed by a local native library when it wouldn't have been before, but // this kind of behavior is pretty platform specific and generally not // recommended anyway, so I don't think we're shooting ourself in the foot // much with that. add_upstream_rust_crates(cmd, sess, dylib, tmpdir, trans); add_local_native_libraries(cmd, sess); add_upstream_native_libraries(cmd, 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 { cmd.args(["-dynamiclib", "-Wl,-dylib"]); if sess.opts.cg.rpath { let mut v = Vec::from_slice("-Wl,-install_name,@rpath/".as_bytes()); v.push_all(out_filename.filename().unwrap()); cmd.arg(v.as_slice()); } } else { cmd.arg("-shared"); } } if sess.targ_cfg.os == abi::OsFreebsd { cmd.args(["-L/usr/local/lib", "-L/usr/local/lib/gcc46", "-L/usr/local/lib/gcc44"]); } else if sess.targ_cfg.os == abi::OsDragonfly { cmd.args(["-L/usr/local/lib", "-L/usr/lib/gcc47", "-L/usr/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.rpath { let sysroot = sess.sysroot(); let target_triple = sess.opts.target_triple.as_slice(); let get_install_prefix_lib_path = || { let install_prefix = option_env!("CFG_PREFIX").expect("CFG_PREFIX"); let tlib = filesearch::relative_target_lib_path(sysroot, target_triple); let mut path = Path::new(install_prefix); path.push(&tlib); path }; let rpath_config = RPathConfig { os: sess.targ_cfg.os, used_crates: sess.cstore.get_used_crates(cstore::RequireDynamic), out_filename: out_filename.clone(), get_install_prefix_lib_path: get_install_prefix_lib_path, realpath: ::util::fs::realpath }; cmd.args(rpath::get_rpath_flags(rpath_config).as_slice()); } // compiler-rt contains implementations of low-level LLVM helpers. This is // used to resolve symbols from the object file we just created, as well as // any system static libraries that may be expecting gcc instead. Most // symbols in libgcc also appear in compiler-rt. // // This is the end of the command line, so this library is used to resolve // *all* undefined symbols in all other libraries, and this is intentional. cmd.arg("-lcompiler-rt"); // Finally add all the linker arguments provided on the command line along // with any #[link_args] attributes found inside the crate cmd.args(sess.opts.cg.link_args.as_slice()); cmd.args(used_link_args.as_slice()); } // # 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(cmd: &mut Command, sess: &Session) { for path in sess.opts.addl_lib_search_paths.borrow().iter() { cmd.arg("-L").arg(path); } let rustpath = filesearch::rust_path(); for path in rustpath.iter() { cmd.arg("-L").arg(path); } // Some platforms take hints about whether a library is static or dynamic. // For those that support this, we ensure we pass the option if the library // was flagged "static" (most defaults are dynamic) to ensure that if // libfoo.a and libfoo.so both exist that the right one is chosen. let takes_hints = sess.targ_cfg.os != abi::OsMacos && sess.targ_cfg.os != abi::OsiOS; let libs = sess.cstore.get_used_libraries(); let libs = libs.borrow(); let mut staticlibs = libs.iter().filter_map(|&(ref l, kind)| { if kind == cstore::NativeStatic {Some(l)} else {None} }); let mut others = libs.iter().filter(|&&(_, kind)| { kind != cstore::NativeStatic }); // Platforms that take hints generally also support the --whole-archive // flag. We need to pass this flag when linking static native libraries to // ensure the entire library is included. // // For more details see #15460, but the gist is that the linker will strip // away any unused objects in the archive if we don't otherwise explicitly // reference them. This can occur for libraries which are just providing // bindings, libraries with generic functions, etc. if takes_hints { cmd.arg("-Wl,--whole-archive").arg("-Wl,-Bstatic"); } let search_path = archive_search_paths(sess); for l in staticlibs { if takes_hints { cmd.arg(format!("-l{}", l)); } else { // -force_load is the OSX equivalent of --whole-archive, but it // involves passing the full path to the library to link. let lib = archive::find_library(l.as_slice(), sess.targ_cfg.os, search_path.as_slice(), &sess.diagnostic().handler); let mut v = b"-Wl,-force_load,".to_vec(); v.push_all(lib.as_vec()); cmd.arg(v.as_slice()); } } if takes_hints { cmd.arg("-Wl,--no-whole-archive").arg("-Wl,-Bdynamic"); } for &(ref l, kind) in others { match kind { cstore::NativeUnknown => { cmd.arg(format!("-l{}", l)); } cstore::NativeFramework => { cmd.arg("-framework").arg(l.as_slice()); } cstore::NativeStatic => unreachable!(), } } } // # 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(cmd: &mut Command, sess: &Session, dylib: bool, tmpdir: &Path, trans: &CrateTranslation) { // All of the heavy lifting has previously been accomplished by the // dependency_format module of the compiler. This is just crawling the // output of that module, adding crates as necessary. // // Linking to a rlib involves just passing it to the linker (the linker // will slurp up the object files inside), and linking to a dynamic library // involves just passing the right -l flag. let data = if dylib { trans.crate_formats.get(&config::CrateTypeDylib) } else { trans.crate_formats.get(&config::CrateTypeExecutable) }; // Invoke get_used_crates to ensure that we get a topological sorting of // crates. let deps = sess.cstore.get_used_crates(cstore::RequireDynamic); for &(cnum, _) in deps.iter() { // We may not pass all crates through to the linker. Some crates may // appear statically in an existing dylib, meaning we'll pick up all the // symbols from the dylib. let kind = match *data.get(cnum as uint - 1) { Some(t) => t, None => continue }; let src = sess.cstore.get_used_crate_source(cnum).unwrap(); match kind { cstore::RequireDynamic => { add_dynamic_crate(cmd, sess, src.dylib.unwrap()) } cstore::RequireStatic => { add_static_crate(cmd, sess, tmpdir, src.rlib.unwrap()) } } } // Converts a library file-stem into a cc -l argument fn unlib<'a>(config: &config::Config, stem: &'a [u8]) -> &'a [u8] { if stem.starts_with("lib".as_bytes()) && config.os != abi::OsWindows { stem.tailn(3) } else { stem } } // Adds the static "rlib" versions of all crates to the command line. fn add_static_crate(cmd: &mut Command, sess: &Session, tmpdir: &Path, cratepath: Path) { // 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 = cratepath.filename_str().unwrap(); let name = name.slice(3, name.len() - 5); // chop off lib/.rlib time(sess.time_passes(), format!("altering {}.rlib", name).as_slice(), (), |()| { 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).as_slice()); sess.abort_if_errors(); } } let handler = &sess.diagnostic().handler; let config = ArchiveConfig { handler: handler, dst: dst.clone(), lib_search_paths: archive_search_paths(sess), os: sess.targ_cfg.os, maybe_ar_prog: sess.opts.cg.ar.clone() }; let mut archive = Archive::open(config); archive.remove_file(format!("{}.o", name).as_slice()); let files = archive.files(); if files.iter().any(|s| s.as_slice().ends_with(".o")) { cmd.arg(dst); } }); } else { cmd.arg(cratepath); } } // Same thing as above, but for dynamic crates instead of static crates. fn add_dynamic_crate(cmd: &mut Command, sess: &Session, cratepath: 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()); // Just need to tell the linker about where the library lives and // what its name is let dir = cratepath.dirname(); if !dir.is_empty() { cmd.arg("-L").arg(dir); } let mut v = Vec::from_slice("-l".as_bytes()); v.push_all(unlib(&sess.targ_cfg, cratepath.filestem().unwrap())); cmd.arg(v.as_slice()); } } // Link in all of our upstream crates' native dependencies. Remember that // all of these upstream native dependencies 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 are 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(cmd: &mut Command, sess: &Session) { // Be sure to use a topological sorting of crates because there may be // interdependencies between native libraries. When passing -nodefaultlibs, // for example, almost all native libraries depend on libc, so we have to // make sure that's all the way at the right (liblibc is near the base of // the dependency chain). // // This passes RequireStatic, but the actual requirement doesn't matter, // we're just getting an ordering of crate numbers, we're not worried about // the paths. let crates = sess.cstore.get_used_crates(cstore::RequireStatic); for (cnum, _) in crates.move_iter() { let libs = csearch::get_native_libraries(&sess.cstore, cnum); for &(kind, ref lib) in libs.iter() { match kind { cstore::NativeUnknown => { cmd.arg(format!("-l{}", *lib)); } cstore::NativeFramework => { cmd.arg("-framework"); cmd.arg(lib.as_slice()); } cstore::NativeStatic => { sess.bug("statics shouldn't be propagated"); } } } } }