Add 'compiler/rustc_codegen_gcc/' from commit 'afae271d5d'

git-subtree-dir: compiler/rustc_codegen_gcc
git-subtree-mainline: ae90dcf020
git-subtree-split: afae271d5d

compiler/rustc_codegen_gcc/src/lib.rs

@@ -0,0 +1,342 @@
+/*
+ * TODO: support #[inline] attributes.
+ * TODO: support LTO.
+ *
+ * TODO: remove the local gccjit LD_LIBRARY_PATH in config.sh.
+ * TODO: remove the object dependency.
+ * TODO: remove the patches.
+ */
+
+#![feature(rustc_private, decl_macro, associated_type_bounds, never_type, trusted_len)]
+#![allow(broken_intra_doc_links)]
+#![recursion_limit="256"]
+#![warn(rust_2018_idioms)]
+#![warn(unused_lifetimes)]
+
+/*extern crate flate2;
+extern crate libc;*/
+extern crate rustc_ast;
+extern crate rustc_codegen_ssa;
+extern crate rustc_data_structures;
+extern crate rustc_errors;
+//extern crate rustc_fs_util;
+extern crate rustc_hir;
+extern crate rustc_metadata;
+extern crate rustc_middle;
+extern crate rustc_mir;
+extern crate rustc_session;
+extern crate rustc_span;
+extern crate rustc_symbol_mangling;
+extern crate rustc_target;
+extern crate snap;
+
+// This prevents duplicating functions and statics that are already part of the host rustc process.
+#[allow(unused_extern_crates)]
+extern crate rustc_driver;
+
+mod abi;
+mod allocator;
+mod archive;
+mod asm;
+mod back;
+mod base;
+mod builder;
+mod callee;
+mod common;
+mod consts;
+mod context;
+mod coverageinfo;
+mod debuginfo;
+mod declare;
+mod intrinsic;
+mod mangled_std_symbols;
+mod mono_item;
+mod type_;
+mod type_of;
+mod va_arg;
+
+use std::any::Any;
+use std::sync::Arc;
+
+use gccjit::{Block, Context, FunctionType, OptimizationLevel};
+use rustc_ast::expand::allocator::AllocatorKind;
+use rustc_codegen_ssa::{CodegenResults, CompiledModule, ModuleCodegen};
+use rustc_codegen_ssa::base::codegen_crate;
+use rustc_codegen_ssa::back::write::{CodegenContext, FatLTOInput, ModuleConfig, TargetMachineFactoryFn};
+use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
+use rustc_codegen_ssa::target_features::supported_target_features;
+use rustc_codegen_ssa::traits::{CodegenBackend, ExtraBackendMethods, ModuleBufferMethods, ThinBufferMethods, WriteBackendMethods};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::{ErrorReported, Handler};
+use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
+use rustc_middle::middle::cstore::EncodedMetadata;
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config::{CrateType, Lto, OptLevel, OutputFilenames};
+use rustc_session::Session;
+use rustc_span::Symbol;
+use rustc_span::fatal_error::FatalError;
+
+use crate::context::unit_name;
+
+pub struct PrintOnPanic<F: Fn() -> String>(pub F);
+
+impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
+    fn drop(&mut self) {
+        if ::std::thread::panicking() {
+            println!("{}", (self.0)());
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct GccCodegenBackend;
+
+impl CodegenBackend for GccCodegenBackend {
+    fn init(&self, sess: &Session) {
+        if sess.lto() != Lto::No {
+            sess.warn("LTO is not supported. You may get a linker error.");
+        }
+    }
+
+    fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>, metadata: EncodedMetadata, need_metadata_module: bool) -> Box<dyn Any> {
+        let target_cpu = target_cpu(tcx.sess);
+        let res = codegen_crate(self.clone(), tcx, target_cpu.to_string(), metadata, need_metadata_module);
+
+        rustc_symbol_mangling::test::report_symbol_names(tcx);
+
+        Box::new(res)
+    }
+
+    fn join_codegen(&self, ongoing_codegen: Box<dyn Any>, sess: &Session) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorReported> {
+        let (codegen_results, work_products) = ongoing_codegen
+            .downcast::<rustc_codegen_ssa::back::write::OngoingCodegen<GccCodegenBackend>>()
+            .expect("Expected GccCodegenBackend's OngoingCodegen, found Box<Any>")
+            .join(sess);
+
+        Ok((codegen_results, work_products))
+    }
+
+    fn link(&self, sess: &Session, mut codegen_results: CodegenResults, outputs: &OutputFilenames) -> Result<(), ErrorReported> {
+        use rustc_codegen_ssa::back::link::link_binary;
+        if let Some(symbols) = codegen_results.crate_info.exported_symbols.get_mut(&CrateType::Dylib) {
+            // TODO: remove when global initializer work without calling a function at runtime.
+            // HACK: since this codegen add some symbols (e.g. __gccGlobalCrateInit) and the UI
+            // tests load libstd.so as a dynamic library, and rustc use a version-script to specify
+            // the symbols visibility, we add * to export all symbols.
+            // It seems other symbols from libstd/libcore are causing some issues here as well.
+            symbols.push("*".to_string());
+        }
+
+        link_binary::<crate::archive::ArArchiveBuilder<'_>>(
+            sess,
+            &codegen_results,
+            outputs,
+        )
+    }
+
+    fn target_features(&self, sess: &Session) -> Vec<Symbol> {
+        target_features(sess)
+    }
+}
+
+impl ExtraBackendMethods for GccCodegenBackend {
+    fn new_metadata<'tcx>(&self, _tcx: TyCtxt<'tcx>, _mod_name: &str) -> Self::Module {
+        GccContext {
+            context: Context::default(),
+        }
+    }
+
+    fn write_compressed_metadata<'tcx>(&self, tcx: TyCtxt<'tcx>, metadata: &EncodedMetadata, gcc_module: &mut Self::Module) {
+        base::write_compressed_metadata(tcx, metadata, gcc_module)
+    }
+
+    fn codegen_allocator<'tcx>(&self, tcx: TyCtxt<'tcx>, mods: &mut Self::Module, kind: AllocatorKind, has_alloc_error_handler: bool) {
+        unsafe { allocator::codegen(tcx, mods, kind, has_alloc_error_handler) }
+    }
+
+    fn compile_codegen_unit<'tcx>(&self, tcx: TyCtxt<'tcx>, cgu_name: Symbol) -> (ModuleCodegen<Self::Module>, u64) {
+        base::compile_codegen_unit(tcx, cgu_name)
+    }
+
+    fn target_machine_factory(&self, _sess: &Session, _opt_level: OptLevel) -> TargetMachineFactoryFn<Self> {
+        // TODO: set opt level.
+        Arc::new(|_| {
+            Ok(())
+        })
+    }
+
+    fn target_cpu<'b>(&self, _sess: &'b Session) -> &'b str {
+        unimplemented!();
+    }
+
+    fn tune_cpu<'b>(&self, _sess: &'b Session) -> Option<&'b str> {
+        None
+        // TODO
+        //llvm_util::tune_cpu(sess)
+    }
+}
+
+pub struct ModuleBuffer;
+
+impl ModuleBufferMethods for ModuleBuffer {
+    fn data(&self) -> &[u8] {
+        unimplemented!();
+    }
+}
+
+pub struct ThinBuffer;
+
+impl ThinBufferMethods for ThinBuffer {
+    fn data(&self) -> &[u8] {
+        unimplemented!();
+    }
+}
+
+pub struct GccContext {
+    context: Context<'static>,
+}
+
+unsafe impl Send for GccContext {}
+// FIXME: that shouldn't be Sync. Parallel compilation is currently disabled with "-Zno-parallel-llvm". Try to disable it here.
+unsafe impl Sync for GccContext {}
+
+impl WriteBackendMethods for GccCodegenBackend {
+    type Module = GccContext;
+    type TargetMachine = ();
+    type ModuleBuffer = ModuleBuffer;
+    type Context = ();
+    type ThinData = ();
+    type ThinBuffer = ThinBuffer;
+
+    fn run_fat_lto(_cgcx: &CodegenContext<Self>, mut modules: Vec<FatLTOInput<Self>>, _cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>) -> Result<LtoModuleCodegen<Self>, FatalError> {
+        // TODO: implement LTO by sending -flto to libgccjit and adding the appropriate gcc linker plugins.
+        // NOTE: implemented elsewhere.
+        let module =
+            match modules.remove(0) {
+                FatLTOInput::InMemory(module) => module,
+                FatLTOInput::Serialized { .. } => {
+                    unimplemented!();
+                    /*info!("pushing serialized module {:?}", name);
+                    let buffer = SerializedModule::Local(buffer);
+                    serialized_modules.push((buffer, CString::new(name).unwrap()));*/
+                }
+            };
+        Ok(LtoModuleCodegen::Fat { module: Some(module), _serialized_bitcode: vec![] })
+    }
+
+    fn run_thin_lto(_cgcx: &CodegenContext<Self>, _modules: Vec<(String, Self::ThinBuffer)>, _cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>) -> Result<(Vec<LtoModuleCodegen<Self>>, Vec<WorkProduct>), FatalError> {
+        unimplemented!();
+    }
+
+    fn print_pass_timings(&self) {
+        unimplemented!();
+    }
+
+    unsafe fn optimize(_cgcx: &CodegenContext<Self>, _diag_handler: &Handler, module: &ModuleCodegen<Self::Module>, config: &ModuleConfig) -> Result<(), FatalError> {
+        //if cgcx.lto == Lto::Fat {
+            //module.module_llvm.context.add_driver_option("-flto");
+        //}
+        module.module_llvm.context.set_optimization_level(to_gcc_opt_level(config.opt_level));
+        Ok(())
+    }
+
+    unsafe fn optimize_thin(_cgcx: &CodegenContext<Self>, _thin: &mut ThinModule<Self>) -> Result<ModuleCodegen<Self::Module>, FatalError> {
+        unimplemented!();
+    }
+
+    unsafe fn codegen(cgcx: &CodegenContext<Self>, diag_handler: &Handler, module: ModuleCodegen<Self::Module>, config: &ModuleConfig) -> Result<CompiledModule, FatalError> {
+        back::write::codegen(cgcx, diag_handler, module, config)
+    }
+
+    fn prepare_thin(_module: ModuleCodegen<Self::Module>) -> (String, Self::ThinBuffer) {
+        unimplemented!();
+    }
+
+    fn serialize_module(_module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer) {
+        unimplemented!();
+    }
+
+    fn run_lto_pass_manager(_cgcx: &CodegenContext<Self>, _module: &ModuleCodegen<Self::Module>, _config: &ModuleConfig, _thin: bool) -> Result<(), FatalError> {
+        // TODO
+        Ok(())
+    }
+
+    fn run_link(cgcx: &CodegenContext<Self>, diag_handler: &Handler, modules: Vec<ModuleCodegen<Self::Module>>) -> Result<ModuleCodegen<Self::Module>, FatalError> {
+        back::write::link(cgcx, diag_handler, modules)
+    }
+}
+
+/*fn target_triple(sess: &Session) -> target_lexicon::Triple {
+    sess.target.llvm_target.parse().unwrap()
+}*/
+
+/// This is the entrypoint for a hot plugged rustc_codegen_gccjit
+#[no_mangle]
+pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
+    Box::new(GccCodegenBackend)
+}
+
+fn to_gcc_opt_level(optlevel: Option<OptLevel>) -> OptimizationLevel {
+    match optlevel {
+        None => OptimizationLevel::None,
+        Some(level) => {
+            match level {
+                OptLevel::No => OptimizationLevel::None,
+                OptLevel::Less => OptimizationLevel::Limited,
+                OptLevel::Default => OptimizationLevel::Standard,
+                OptLevel::Aggressive => OptimizationLevel::Aggressive,
+                OptLevel::Size | OptLevel::SizeMin => OptimizationLevel::Limited,
+            }
+        },
+    }
+}
+
+fn create_function_calling_initializers<'gcc, 'tcx>(tcx: TyCtxt<'tcx>, context: &Context<'gcc>, block: Block<'gcc>) {
+    let codegen_units = tcx.collect_and_partition_mono_items(()).1;
+    for codegen_unit in codegen_units {
+        let codegen_init_func = context.new_function(None, FunctionType::Extern, context.new_type::<()>(), &[],
+            &format!("__gccGlobalInit{}", unit_name(&codegen_unit)), false);
+        block.add_eval(None, context.new_call(None, codegen_init_func, &[]));
+    }
+}
+
+fn handle_native(name: &str) -> &str {
+    if name != "native" {
+        return name;
+    }
+
+    unimplemented!();
+    /*unsafe {
+        let mut len = 0;
+        let ptr = llvm::LLVMRustGetHostCPUName(&mut len);
+        str::from_utf8(slice::from_raw_parts(ptr as *const u8, len)).unwrap()
+    }*/
+}
+
+pub fn target_cpu(sess: &Session) -> &str {
+    let name = sess.opts.cg.target_cpu.as_ref().unwrap_or(&sess.target.cpu);
+    handle_native(name)
+}
+
+pub fn target_features(sess: &Session) -> Vec<Symbol> {
+    supported_target_features(sess)
+        .iter()
+        .filter_map(
+            |&(feature, gate)| {
+                if sess.is_nightly_build() || gate.is_none() { Some(feature) } else { None }
+            },
+        )
+        .filter(|_feature| {
+            /*if feature.starts_with("sse") {
+                return true;
+            }*/
+            // TODO: implement a way to get enabled feature in libgccjit.
+            //println!("Feature: {}", feature);
+            /*let llvm_feature = to_llvm_feature(sess, feature);
+            let cstr = CString::new(llvm_feature).unwrap();
+            unsafe { llvm::LLVMRustHasFeature(target_machine, cstr.as_ptr()) }*/
+            false
+        })
+        .map(|feature| Symbol::intern(feature))
+        .collect()
+}