diff options
Diffstat (limited to 'src/librustc_codegen_ssa/back/link.rs')
| -rw-r--r-- | src/librustc_codegen_ssa/back/link.rs | 196 |
1 files changed, 135 insertions, 61 deletions
diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs index ce158fb07da..aa4b51f1acb 100644 --- a/src/librustc_codegen_ssa/back/link.rs +++ b/src/librustc_codegen_ssa/back/link.rs @@ -11,7 +11,9 @@ use rustc_session::search_paths::PathKind; /// need out of the shared crate context before we get rid of it. use rustc_session::{filesearch, Session}; use rustc_span::symbol::Symbol; -use rustc_target::spec::{LinkerFlavor, LldFlavor, PanicStrategy, RelocModel, RelroLevel}; +use rustc_target::spec::crt_objects::CrtObjectsFallback; +use rustc_target::spec::{LinkOutputKind, LinkerFlavor, LldFlavor}; +use rustc_target::spec::{PanicStrategy, RelocModel, RelroLevel}; use super::archive::ArchiveBuilder; use super::command::Command; @@ -609,6 +611,55 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>( .note(&format!("{:?}", &cmd)) .note(&escape_string(&output)) .emit(); + + // If MSVC's `link.exe` was expected but the return code + // is not a Microsoft LNK error then suggest a way to fix or + // install the Visual Studio build tools. + if let Some(code) = prog.status.code() { + if sess.target.target.options.is_like_msvc + && flavor == LinkerFlavor::Msvc + // Respect the command line override + && sess.opts.cg.linker.is_none() + // Match exactly "link.exe" + && linker_path.to_str() == Some("link.exe") + // All Microsoft `link.exe` linking error codes are + // four digit numbers in the range 1000 to 9999 inclusive + && (code < 1000 || code > 9999) + { + let is_vs_installed = windows_registry::find_vs_version().is_ok(); + let has_linker = windows_registry::find_tool( + &sess.opts.target_triple.triple(), + "link.exe", + ) + .is_some(); + + sess.note_without_error("`link.exe` returned an unexpected error"); + if is_vs_installed && has_linker { + // the linker is broken + sess.note_without_error( + "the Visual Studio build tools may need to be repaired \ + using the Visual Studio installer", + ); + sess.note_without_error( + "or a necessary component may be missing from the \ + \"C++ build tools\" workload", + ); + } else if is_vs_installed { + // the linker is not installed + sess.note_without_error( + "in the Visual Studio installer, ensure the \ + \"C++ build tools\" workload is selected", + ); + } else { + // visual studio is not installed + sess.note_without_error( + "you may need to install Visual Studio build tools with the \ + \"C++ build tools\" workload", + ); + } + } + } + sess.abort_if_errors(); } info!("linker stderr:\n{}", escape_string(&prog.stderr)); @@ -1130,33 +1181,70 @@ fn exec_linker( } } -/// Add begin object files defined by the target spec. -fn add_pre_link_objects(cmd: &mut dyn Linker, sess: &Session, crate_type: CrateType) { - let pre_link_objects = if crate_type == CrateType::Executable { - &sess.target.target.options.pre_link_objects_exe - } else { - &sess.target.target.options.pre_link_objects_dll +fn link_output_kind(sess: &Session, crate_type: CrateType) -> LinkOutputKind { + let kind = match (crate_type, sess.crt_static(Some(crate_type)), sess.relocation_model()) { + (CrateType::Executable, false, RelocModel::Pic) => LinkOutputKind::DynamicPicExe, + (CrateType::Executable, false, _) => LinkOutputKind::DynamicNoPicExe, + (CrateType::Executable, true, RelocModel::Pic) => LinkOutputKind::StaticPicExe, + (CrateType::Executable, true, _) => LinkOutputKind::StaticNoPicExe, + (_, true, _) => LinkOutputKind::StaticDylib, + (_, false, _) => LinkOutputKind::DynamicDylib, }; - for obj in pre_link_objects { - cmd.add_object(&get_object_file_path(sess, obj)); + + // Adjust the output kind to target capabilities. + let pic_exe_supported = sess.target.target.options.position_independent_executables; + let static_pic_exe_supported = false; // FIXME: Add this option to target specs. + let static_dylib_supported = sess.target.target.options.crt_static_allows_dylibs; + match kind { + LinkOutputKind::DynamicPicExe if !pic_exe_supported => LinkOutputKind::DynamicNoPicExe, + LinkOutputKind::StaticPicExe if !static_pic_exe_supported => LinkOutputKind::StaticNoPicExe, + LinkOutputKind::StaticDylib if !static_dylib_supported => LinkOutputKind::DynamicDylib, + _ => kind, } +} - if crate_type == CrateType::Executable && sess.crt_static(Some(crate_type)) { - for obj in &sess.target.target.options.pre_link_objects_exe_crt { - cmd.add_object(&get_object_file_path(sess, obj)); - } +/// Whether we link to our own CRT objects instead of relying on gcc to pull them. +/// We only provide such support for a very limited number of targets. +fn crt_objects_fallback(sess: &Session, crate_type: CrateType) -> bool { + match sess.target.target.options.crt_objects_fallback { + // FIXME: Find a better heuristic for "native musl toolchain is available", + // based on host and linker path, for example. + // (https://github.com/rust-lang/rust/pull/71769#issuecomment-626330237). + Some(CrtObjectsFallback::Musl) => sess.crt_static(Some(crate_type)), + // FIXME: Find some heuristic for "native mingw toolchain is available", + // likely based on `get_crt_libs_path` (https://github.com/rust-lang/rust/pull/67429). + Some(CrtObjectsFallback::Mingw) => sess.target.target.target_vendor != "uwp", + // FIXME: Figure out cases in which WASM needs to link with a native toolchain. + Some(CrtObjectsFallback::Wasm) => true, + None => false, } } -/// Add end object files defined by the target spec. -fn add_post_link_objects(cmd: &mut dyn Linker, sess: &Session, crate_type: CrateType) { - for obj in &sess.target.target.options.post_link_objects { +/// Add pre-link object files defined by the target spec. +fn add_pre_link_objects( + cmd: &mut dyn Linker, + sess: &Session, + link_output_kind: LinkOutputKind, + fallback: bool, +) { + let opts = &sess.target.target.options; + let objects = if fallback { &opts.pre_link_objects_fallback } else { &opts.pre_link_objects }; + for obj in objects.get(&link_output_kind).iter().copied().flatten() { cmd.add_object(&get_object_file_path(sess, obj)); } - if sess.crt_static(Some(crate_type)) { - for obj in &sess.target.target.options.post_link_objects_crt { - cmd.add_object(&get_object_file_path(sess, obj)); - } +} + +/// Add post-link object files defined by the target spec. +fn add_post_link_objects( + cmd: &mut dyn Linker, + sess: &Session, + link_output_kind: LinkOutputKind, + fallback: bool, +) { + let opts = &sess.target.target.options; + let objects = if fallback { &opts.post_link_objects_fallback } else { &opts.post_link_objects }; + for obj in objects.get(&link_output_kind).iter().copied().flatten() { + cmd.add_object(&get_object_file_path(sess, obj)); } } @@ -1342,38 +1430,6 @@ fn add_library_search_dirs(cmd: &mut dyn Linker, sess: &Session) { cmd.include_path(&fix_windows_verbatim_for_gcc(&lib_path)); } -/// Add options requesting executables to be position-independent or not position-independent. -fn add_position_independent_executable_args( - cmd: &mut dyn Linker, - sess: &Session, - flavor: LinkerFlavor, - crate_type: CrateType, - codegen_results: &CodegenResults, -) { - if crate_type != CrateType::Executable { - return; - } - - if sess.target.target.options.position_independent_executables { - let attr_link_args = &*codegen_results.crate_info.link_args; - let mut user_defined_link_args = sess.opts.cg.link_args.iter().chain(attr_link_args); - if sess.relocation_model() == RelocModel::Pic - && !sess.crt_static(Some(crate_type)) - && !user_defined_link_args.any(|x| x == "-static") - { - cmd.position_independent_executable(); - return; - } - } - - // Recent versions of gcc can be configured to generate position - // independent executables by default. We have to pass -no-pie to - // explicitly turn that off. Not applicable to ld. - if sess.target.target.options.linker_is_gnu && flavor != LinkerFlavor::Ld { - cmd.no_position_independent_executable(); - } -} - /// Add options making relocation sections in the produced ELF files read-only /// and suppressing lazy binding. fn add_relro_args(cmd: &mut dyn Linker, sess: &Session) { @@ -1439,6 +1495,8 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>( // to the linker args construction. assert!(base_cmd.get_args().is_empty() || sess.target.target.target_vendor == "uwp"); let cmd = &mut *codegen_results.linker_info.to_linker(base_cmd, &sess, flavor, target_cpu); + let link_output_kind = link_output_kind(sess, crate_type); + let crt_objects_fallback = crt_objects_fallback(sess, crate_type); // NO-OPT-OUT, OBJECT-FILES-MAYBE, CUSTOMIZATION-POINT add_pre_link_args(cmd, sess, flavor, crate_type); @@ -1455,8 +1513,13 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>( cmd.arg(format!("--dynamic-linker={}ld.so.1", prefix)); } + // NO-OPT-OUT, OBJECT-FILES-NO + if crt_objects_fallback { + cmd.no_crt_objects(); + } + // NO-OPT-OUT, OBJECT-FILES-YES - add_pre_link_objects(cmd, sess, crate_type); + add_pre_link_objects(cmd, sess, link_output_kind, crt_objects_fallback); // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER if sess.target.target.options.is_like_emscripten { @@ -1515,7 +1578,16 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>( } // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER - add_position_independent_executable_args(cmd, sess, flavor, crate_type, codegen_results); + // FIXME: Support `StaticPicExe` correctly. + match link_output_kind { + LinkOutputKind::DynamicPicExe | LinkOutputKind::StaticPicExe => { + cmd.position_independent_executable() + } + LinkOutputKind::DynamicNoPicExe | LinkOutputKind::StaticNoPicExe => { + cmd.no_position_independent_executable() + } + _ => {} + } // OBJECT-FILES-NO, AUDIT-ORDER add_relro_args(cmd, sess); @@ -1545,12 +1617,14 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>( ); // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER - // Tell the linker what we're doing. - if crate_type != CrateType::Executable { - cmd.build_dylib(out_filename); - } - if crate_type == CrateType::Executable && sess.crt_static(Some(crate_type)) { - cmd.build_static_executable(); + // FIXME: Merge with the previous `link_output_kind` match, + // and support `StaticPicExe` and `StaticDylib` correctly. + match link_output_kind { + LinkOutputKind::StaticNoPicExe | LinkOutputKind::StaticPicExe => { + cmd.build_static_executable() + } + LinkOutputKind::DynamicDylib | LinkOutputKind::StaticDylib => cmd.build_dylib(out_filename), + _ => {} } // OBJECT-FILES-NO, AUDIT-ORDER @@ -1576,7 +1650,7 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>( add_late_link_args(cmd, sess, flavor, crate_type, codegen_results); // NO-OPT-OUT, OBJECT-FILES-YES - add_post_link_objects(cmd, sess, crate_type); + add_post_link_objects(cmd, sess, link_output_kind, crt_objects_fallback); // NO-OPT-OUT, OBJECT-FILES-MAYBE, CUSTOMIZATION-POINT add_post_link_args(cmd, sess, flavor); |