diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/attributes.rs | 44 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm/ffi.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm_util.rs | 75 |
3 files changed, 104 insertions, 23 deletions
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index e06c1c825f6..9e5e2b1039e 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -13,6 +13,7 @@ use rustc_middle::ty::query::Providers; use rustc_middle::ty::{self, TyCtxt}; use rustc_session::config::OptLevel; use rustc_session::Session; +use rustc_target::spec::abi::Abi; use rustc_target::spec::{SanitizerSet, StackProbeType}; use crate::attributes; @@ -293,7 +294,7 @@ pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty:: // The target doesn't care; the subtarget reads our attribute. apply_tune_cpu_attr(cx, llfn); - let function_features = codegen_fn_attrs + let mut function_features = codegen_fn_attrs .target_features .iter() .map(|f| { @@ -305,23 +306,10 @@ pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty:: InstructionSetAttr::ArmT32 => "+thumb-mode".to_string(), })) .collect::<Vec<String>>(); - if !function_features.is_empty() { - let mut global_features = llvm_util::llvm_global_features(cx.tcx.sess); - global_features.extend(function_features.into_iter()); - let features = global_features.join(","); - let val = CString::new(features).unwrap(); - llvm::AddFunctionAttrStringValue( - llfn, - llvm::AttributePlace::Function, - cstr!("target-features"), - &val, - ); - } - // Note that currently the `wasm-import-module` doesn't do anything, but - // eventually LLVM 7 should read this and ferry the appropriate import - // module to the output file. if cx.tcx.sess.target.is_like_wasm { + // If this function is an import from the environment but the wasm + // import has a specific module/name, apply them here. if let Some(module) = wasm_import_module(cx.tcx, instance.def_id()) { llvm::AddFunctionAttrStringValue( llfn, @@ -340,6 +328,30 @@ pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty:: &name, ); } + + // The `"wasm"` abi on wasm targets automatically enables the + // `+multivalue` feature because the purpose of the wasm abi is to match + // the WebAssembly specification, which has this feature. This won't be + // needed when LLVM enables this `multivalue` feature by default. + if !cx.tcx.is_closure(instance.def_id()) { + let abi = cx.tcx.fn_sig(instance.def_id()).abi(); + if abi == Abi::Wasm { + function_features.push("+multivalue".to_string()); + } + } + } + + if !function_features.is_empty() { + let mut global_features = llvm_util::llvm_global_features(cx.tcx.sess); + global_features.extend(function_features.into_iter()); + let features = global_features.join(","); + let val = CString::new(features).unwrap(); + llvm::AddFunctionAttrStringValue( + llfn, + llvm::AttributePlace::Function, + cstr!("target-features"), + &val, + ); } } diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 70f78c07c65..54a8249b175 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -2128,7 +2128,13 @@ extern "C" { pub fn LLVMRustHasFeature(T: &TargetMachine, s: *const c_char) -> bool; pub fn LLVMRustPrintTargetCPUs(T: &TargetMachine); - pub fn LLVMRustPrintTargetFeatures(T: &TargetMachine); + pub fn LLVMRustGetTargetFeaturesCount(T: &TargetMachine) -> size_t; + pub fn LLVMRustGetTargetFeature( + T: &TargetMachine, + Index: size_t, + Feature: &mut *const c_char, + Desc: &mut *const c_char, + ); pub fn LLVMRustGetHostCPUName(len: *mut usize) -> *const c_char; pub fn LLVMRustCreateTargetMachine( diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index e80de2bc902..b44553e4f6d 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -10,6 +10,7 @@ use rustc_span::symbol::Symbol; use rustc_target::spec::{MergeFunctions, PanicStrategy}; use std::ffi::{CStr, CString}; +use std::ptr; use std::slice; use std::str; use std::sync::atomic::{AtomicBool, Ordering}; @@ -192,15 +193,77 @@ pub fn print_passes() { } } +fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> { + let len = unsafe { llvm::LLVMRustGetTargetFeaturesCount(tm) }; + let mut ret = Vec::with_capacity(len); + for i in 0..len { + unsafe { + let mut feature = ptr::null(); + let mut desc = ptr::null(); + llvm::LLVMRustGetTargetFeature(tm, i, &mut feature, &mut desc); + if feature.is_null() || desc.is_null() { + bug!("LLVM returned a `null` target feature string"); + } + let feature = CStr::from_ptr(feature).to_str().unwrap_or_else(|e| { + bug!("LLVM returned a non-utf8 feature string: {}", e); + }); + let desc = CStr::from_ptr(desc).to_str().unwrap_or_else(|e| { + bug!("LLVM returned a non-utf8 feature string: {}", e); + }); + ret.push((feature, desc)); + } + } + ret +} + +fn print_target_features(sess: &Session, tm: &llvm::TargetMachine) { + let mut target_features = llvm_target_features(tm); + let mut rustc_target_features = supported_target_features(sess) + .iter() + .filter_map(|(feature, _gate)| { + let llvm_feature = to_llvm_feature(sess, *feature); + // LLVM asserts that these are sorted. LLVM and Rust both use byte comparison for these strings. + target_features.binary_search_by_key(&llvm_feature, |(f, _d)| *f).ok().map(|index| { + let (_f, desc) = target_features.remove(index); + (*feature, desc) + }) + }) + .collect::<Vec<_>>(); + rustc_target_features.extend_from_slice(&[( + "crt-static", + "Enables C Run-time Libraries to be statically linked", + )]); + let max_feature_len = target_features + .iter() + .chain(rustc_target_features.iter()) + .map(|(feature, _desc)| feature.len()) + .max() + .unwrap_or(0); + + println!("Features supported by rustc for this target:"); + for (feature, desc) in &rustc_target_features { + println!(" {1:0$} - {2}.", max_feature_len, feature, desc); + } + println!("\nCode-generation features supported by LLVM for this target:"); + for (feature, desc) in &target_features { + println!(" {1:0$} - {2}.", max_feature_len, feature, desc); + } + if target_features.len() == 0 { + println!(" Target features listing is not supported by this LLVM version."); + } + println!("\nUse +feature to enable a feature, or -feature to disable it."); + println!("For example, rustc -C target-cpu=mycpu -C target-feature=+feature1,-feature2\n"); + println!("Code-generation features cannot be used in cfg or #[target_feature],"); + println!("and may be renamed or removed in a future version of LLVM or rustc.\n"); +} + pub(crate) fn print(req: PrintRequest, sess: &Session) { require_inited(); let tm = create_informational_target_machine(sess); - unsafe { - match req { - PrintRequest::TargetCPUs => llvm::LLVMRustPrintTargetCPUs(tm), - PrintRequest::TargetFeatures => llvm::LLVMRustPrintTargetFeatures(tm), - _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req), - } + match req { + PrintRequest::TargetCPUs => unsafe { llvm::LLVMRustPrintTargetCPUs(tm) }, + PrintRequest::TargetFeatures => print_target_features(sess, tm), + _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req), } } |