Sync from rust (#107)

* Rebase fallout.

* Move rustc_middle::middle::cstore to rustc_session.

* Create more accurate debuginfo for vtables.

Before this commit all vtables would have the same name "vtable" in
debuginfo. Now they get a name that identifies the implementing type
and the trait that is being implemented.

* Remove alloc::prelude

As per the libs team decision in #58935.

Closes #58935

* Make hash_result an Option.

* Properly check `target_features` not to trigger an assertion

* Add LLVM CFI support to the Rust compiler

This commit adds LLVM Control Flow Integrity (CFI) support to the Rust
compiler. It initially provides forward-edge control flow protection for
Rust-compiled code only by aggregating function pointers in groups
identified by their number of arguments.

Forward-edge control flow protection for C or C++ and Rust -compiled
code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code
share the same virtual address space) will be provided in later work as
part of this project by defining and using compatible type identifiers
(see Type metadata in the design document in the tracking issue #89653).

LLVM CFI can be enabled with -Zsanitizer=cfi and requires LTO (i.e.,
-Clto).

* Update to nightly-2021-10-30

* Add deduplication of constant values as rustc relies on LLVM doing that

Co-authored-by: Camille GILLOT <gillot.camille@gmail.com>
Co-authored-by: Michael Woerister <michaelwoerister@posteo>
Co-authored-by: Amanieu d'Antras <amanieu@gmail.com>
Co-authored-by: Yuki Okushi <yuki.okushi@huawei.com>
Co-authored-by: Ramon de C Valle <rcvalle@users.noreply.github.com>

example/alloc_example.rs

@@ -1,10 +1,10 @@
-#![feature(start, box_syntax, core_intrinsics, alloc_prelude, alloc_error_handler)]
+#![feature(start, box_syntax, core_intrinsics, alloc_error_handler)]
 #![no_std]
 
 extern crate alloc;
 extern crate alloc_system;
 
-use alloc::prelude::v1::*;
+use alloc::boxed::Box;
 
 use alloc_system::System;
 

rust-toolchain

@@ -1 +1 @@
-nightly-2021-09-28
+nightly-2021-10-30

src/archive.rs

@@ -1,12 +1,11 @@
 use std::fs::File;
 use std::path::{Path, PathBuf};
 
-use rustc_session::Session;
 use rustc_codegen_ssa::back::archive::ArchiveBuilder;
+use rustc_session::Session;
 
 use rustc_data_structures::temp_dir::MaybeTempDir;
-use rustc_middle::middle::cstore::DllImport;
-
+use rustc_session::cstore::DllImport;
 
 struct ArchiveConfig<'a> {
     sess: &'a Session,

src/asm.rs

@@ -118,7 +118,7 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         true
     }
 
-    fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], rust_operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, _span: &[Span]) {
+    fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], rust_operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, _span: &[Span], _instance: Instance<'_>) {
         let asm_arch = self.tcx.sess.asm_arch.unwrap();
         let is_x86 = matches!(asm_arch, InlineAsmArch::X86 | InlineAsmArch::X86_64);
         let att_dialect = is_x86 && options.contains(InlineAsmOptions::ATT_SYNTAX);

src/base.rs

@@ -7,7 +7,6 @@ use gccjit::{
     GlobalKind,
 };
 use rustc_middle::dep_graph;
-use rustc_middle::middle::cstore::EncodedMetadata;
 use rustc_middle::middle::exported_symbols;
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::mir::mono::Linkage;
@@ -15,6 +14,7 @@ use rustc_codegen_ssa::{ModuleCodegen, ModuleKind};
 use rustc_codegen_ssa::base::maybe_create_entry_wrapper;
 use rustc_codegen_ssa::mono_item::MonoItemExt;
 use rustc_codegen_ssa::traits::DebugInfoMethods;
+use rustc_metadata::EncodedMetadata;
 use rustc_session::config::DebugInfo;
 use rustc_span::Symbol;
 
@@ -59,7 +59,13 @@ pub fn compile_codegen_unit<'tcx>(tcx: TyCtxt<'tcx>, cgu_name: Symbol) -> (Modul
     let start_time = Instant::now();
 
     let dep_node = tcx.codegen_unit(cgu_name).codegen_dep_node(tcx);
-    let (module, _) = tcx.dep_graph.with_task(dep_node, tcx, cgu_name, module_codegen, dep_graph::hash_result);
+    let (module, _) = tcx.dep_graph.with_task(
+        dep_node,
+        tcx,
+        cgu_name,
+        module_codegen,
+        Some(dep_graph::hash_result),
+    );
     let time_to_codegen = start_time.elapsed();
     drop(prof_timer);
 
@@ -152,7 +158,7 @@ pub fn write_compressed_metadata<'tcx>(tcx: TyCtxt<'tcx>, metadata: &EncodedMeta
 
     let context = &gcc_module.context;
     let mut compressed = rustc_metadata::METADATA_HEADER.to_vec();
-    FrameEncoder::new(&mut compressed).write_all(&metadata.raw_data).unwrap();
+    FrameEncoder::new(&mut compressed).write_all(&metadata.raw_data()).unwrap();
 
     let name = exported_symbols::metadata_symbol_name(tcx);
     let typ = context.new_array_type(None, context.new_type::<u8>(), compressed.len() as i32);

src/builder.rs

@@ -910,6 +910,16 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         // TODO(antoyo)
     }
 
+    fn type_metadata(&mut self, _function: RValue<'gcc>, _typeid: String) {
+        // Unsupported.
+    }
+
+    fn typeid_metadata(&mut self, _typeid: String) -> RValue<'gcc> {
+        // Unsupported.
+        self.context.new_rvalue_from_int(self.int_type, 0)
+    }
+
+
     fn store(&mut self, val: RValue<'gcc>, ptr: RValue<'gcc>, align: Align) -> RValue<'gcc> {
         self.store_with_flags(val, ptr, align, MemFlags::empty())
     }

src/consts.rs

@@ -31,9 +31,13 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
 impl<'gcc, 'tcx> StaticMethods for CodegenCx<'gcc, 'tcx> {
     fn static_addr_of(&self, cv: RValue<'gcc>, align: Align, kind: Option<&str>) -> RValue<'gcc> {
-        if let Some(global_value) = self.const_globals.borrow().get(&cv) {
-            // TODO(antoyo): upgrade alignment.
-            return *global_value;
+        // TODO(antoyo): implement a proper rvalue comparison in libgccjit instead of doing the
+        // following:
+        for (value, variable) in &*self.const_globals.borrow() {
+            if format!("{:?}", value) == format!("{:?}", cv) {
+                // TODO(antoyo): upgrade alignment.
+                return *variable;
+            }
         }
         let global_value = self.static_addr_of_mut(cv, align, kind);
         // TODO(antoyo): set global constant.

src/debuginfo.rs

@@ -2,7 +2,7 @@ use gccjit::RValue;
 use rustc_codegen_ssa::mir::debuginfo::{FunctionDebugContext, VariableKind};
 use rustc_codegen_ssa::traits::{DebugInfoBuilderMethods, DebugInfoMethods};
 use rustc_middle::mir;
-use rustc_middle::ty::{Instance, Ty};
+use rustc_middle::ty::{Instance, PolyExistentialTraitRef, Ty};
 use rustc_span::{SourceFile, Span, Symbol};
 use rustc_target::abi::Size;
 use rustc_target::abi::call::FnAbi;
@@ -31,7 +31,7 @@ impl<'a, 'gcc, 'tcx> DebugInfoBuilderMethods for Builder<'a, 'gcc, 'tcx> {
 }
 
 impl<'gcc, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
-    fn create_vtable_metadata(&self, _ty: Ty<'tcx>, _vtable: Self::Value) {
+    fn create_vtable_metadata(&self, _ty: Ty<'tcx>, _trait_ref: Option<PolyExistentialTraitRef<'tcx>>, _vtable: Self::Value) {
         // TODO(antoyo)
     }
 

src/intrinsic/mod.rs

@@ -367,6 +367,11 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         // TODO(antoyo)
     }
 
+    fn type_test(&mut self, _pointer: Self::Value, _typeid: Self::Value) -> Self::Value {
+        // Unsupported.
+        self.context.new_rvalue_from_int(self.int_type, 0)
+    }
+
     fn va_start(&mut self, _va_list: RValue<'gcc>) -> RValue<'gcc> {
         unimplemented!();
     }

src/lib.rs

@@ -60,8 +60,8 @@ 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_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
-use rustc_middle::middle::cstore::EncodedMetadata;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{Lto, OptLevel, OutputFilenames};
 use rustc_session::Session;