Cleanup

Author: antoyo

Readme.md

@@ -177,7 +177,7 @@ To have the correct file paths in `gdb` instead of `/usr/src/debug/gcc/libstdc++
 Maybe by calling the following at the beginning of gdb:
 
 ```
-set substitute-path /usr/src/debug/gcc /home/bouanto/Ordinateur/Programmation/Projets/gcc-repo/gcc
+set substitute-path /usr/src/debug/gcc /path/to/gcc-repo/gcc
 ```
 
 TODO: but that's not what I remember I was doing.

example/alloc_example.rs

@@ -1,4 +1,4 @@
-#![feature(start, box_syntax, core_intrinsics, alloc_error_handler)]
+#![feature(start, box_syntax, core_intrinsics, alloc_error_handler, lang_items)]
 #![no_std]
 
 extern crate alloc;
@@ -26,6 +26,16 @@ fn alloc_error_handler(_: alloc::alloc::Layout) -> ! {
     core::intrinsics::abort();
 }
 
+#[lang = "eh_personality"]
+fn eh_personality() -> ! {
+    loop {}
+}
+
+#[no_mangle]
+unsafe extern "C" fn _Unwind_Resume() {
+    core::intrinsics::unreachable();
+}
+
 #[start]
 fn main(_argc: isize, _argv: *const *const u8) -> isize {
     let world: Box<&str> = box "Hello World!\0";

src/asm.rs

@@ -352,7 +352,7 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                     inputs.push(AsmInOperand {
                         constraint: "X".into(),
                         rust_idx,
-                        val: get_fn(self.cx, instance, false).get_address(None),
+                        val: get_fn(self.cx, instance).get_address(None),
                     });
                 }
 
@@ -738,7 +738,7 @@ impl<'gcc, 'tcx> AsmMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                         }
 
                         GlobalAsmOperandRef::SymFn { instance } => {
-                            let function = get_fn(self, instance, false);
+                            let function = get_fn(self, instance);
                             self.add_used_function(function);
                             // TODO(@Amanieu): Additional mangling is needed on
                             // some targets to add a leading underscore (Mach-O)

src/base.rs

@@ -91,12 +91,6 @@ pub fn compile_codegen_unit<'tcx>(tcx: TyCtxt<'tcx>, cgu_name: Symbol, supports_
         context.add_command_line_option("-fexceptions");
         context.add_driver_option("-fexceptions");
 
-        /*context.add_command_line_option("-fasynchronous-unwind-tables");
-        context.add_driver_option("-fasynchronous-unwind-tables");
-
-        context.add_command_line_option("-funwind-tables");
-        context.add_driver_option("-funwind-tables");*/
-
         // TODO(antoyo): only set on x86 platforms.
         context.add_command_line_option("-masm=intel");
         // TODO(antoyo): only add the following cli argument if the feature is supported.
@@ -156,8 +150,7 @@ pub fn compile_codegen_unit<'tcx>(tcx: TyCtxt<'tcx>, cgu_name: Symbol, supports_
             context.set_keep_intermediates(true);
         }
 
-        // TODO(bjorn3): Remove once unwinding is properly implemented
-        // TODO: remove.
+        // NOTE: The codegen generates unrechable blocks.
         context.set_allow_unreachable_blocks(true);
 
         {

src/builder.rs

@@ -457,7 +457,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
 
         let current_block = self.block.clone();
         self.block = try_block;
-        let call = self.call(typ, func, args, None); // TODO: use funclet here?
+        let call = self.call(typ, func, args, None); // TODO(antoyo): use funclet here?
         self.block = current_block;
 
         let return_value = self.current_func()
@@ -471,8 +471,6 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
             self.block.add_try_finally(None, try_block, catch);
         }
         else {
-            // FIXME: FIXME: FIXME: Seems like bad (_URC_NO_REASON) return code, perhaps because the cleanup pad was created properly.
-            println!("Try/catch in {:?}", self.current_func());
             self.block.add_try_catch(None, try_block, catch);
         }
 
@@ -1197,26 +1195,16 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn set_personality_fn(&mut self, personality: RValue<'gcc>) {
-        let personality = self.rvalue_as_function(personality); // FIXME: why calling
-        //rvalue_as_function doesn't work?
-        //let personality = unsafe { std::mem::transmute(personality) };
+        let personality = self.rvalue_as_function(personality);
         #[cfg(feature="master")]
         self.current_func().set_personality_function(personality);
-        // FIXME: rustc manages to generate the symbol DW.ref.rust_eh_personality multiple times
-        // for the same asm file, which causes an assembler error.
     }
 
     fn cleanup_landing_pad(&mut self, _ty: Type<'gcc>, pers_fn: RValue<'gcc>) -> RValue<'gcc> {
         self.set_personality_fn(pers_fn);
 
-        /*
-         * Matching GCC exception handling with LLVM:
-         *
-         *    GCC                 LLVM
-         *    CATCH_EXPR          landing pad catch clause
-         *    TRY_FINALLY_EXPR    cleanup
-         */
-
+        // NOTE: insert the current block in a variable so that a later call to invoke knows to
+        // generate a try/finally instead of a try/catch for this block.
         self.cleanup_blocks.borrow_mut().insert(self.block);
 
         let eh_pointer_builtin = self.cx.context.get_target_builtin_function("__builtin_eh_pointer");

src/callee.rs

@@ -1,11 +1,9 @@
 #[cfg(feature="master")]
 use gccjit::{FnAttribute, Visibility};
-use gccjit::{FunctionType, RValue, Function};
-use rustc_codegen_ssa::traits::BaseTypeMethods;
+use gccjit::{FunctionType, Function};
 use rustc_middle::ty::{self, Instance, TypeVisitable};
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
 
-use crate::abi::FnAbiGccExt;
 use crate::attributes;
 use crate::context::CodegenCx;
 
@@ -16,7 +14,7 @@ use crate::context::CodegenCx;
 ///
 /// - `cx`: the crate context
 /// - `instance`: the instance to be instantiated
-pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>, dont_cache: bool) -> Function<'gcc> {
+pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>) -> Function<'gcc> {
     let tcx = cx.tcx();
 
     assert!(!instance.substs.needs_infer());
@@ -31,7 +29,9 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>,
     let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
 
     let func =
-        if let Some(func) = cx.get_declared_value(&sym) {
+        if let Some(_func) = cx.get_declared_value(&sym) {
+            // FIXME: we never reach this because get_declared_value only returns global variables
+            // and here we try to get a function.
             unreachable!();
             /*
             // Create a fn pointer with the new signature.
@@ -70,10 +70,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>,
         }
         else {
             cx.linkage.set(FunctionType::Extern);
-            /*if sym == "rust_eh_personality" {
-                panic!();
-            }*/
-            let func = cx.declare_fn(&sym, &fn_abi, dont_cache);
+            let func = cx.declare_fn(&sym, &fn_abi);
 
             attributes::from_fn_attrs(cx, func, instance);
 
@@ -171,9 +168,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>,
             func
         };
 
-    //if !dont_cache {
-        cx.function_instances.borrow_mut().insert(instance, func);
-    //}
+    cx.function_instances.borrow_mut().insert(instance, func);
 
     func
 }

src/context.rs

@@ -1,6 +1,6 @@
 use std::cell::{Cell, RefCell};
 
-use gccjit::{Block, CType, Context, Function, FunctionPtrType, FunctionType, LValue, RValue, Type, FnAttribute};
+use gccjit::{Block, CType, Context, Function, FunctionPtrType, FunctionType, LValue, RValue, Type};
 use rustc_codegen_ssa::base::wants_msvc_seh;
 use rustc_codegen_ssa::traits::{
     BackendTypes,
@@ -259,8 +259,8 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     pub fn rvalue_as_function(&self, value: RValue<'gcc>) -> Function<'gcc> {
         let function: Function<'gcc> = unsafe { std::mem::transmute(value) };
         // FIXME: seems like self.functions get overwritten for rust_eh_personality.
-        /*debug_assert!(self.functions.borrow().values().find(|value| **value == function).is_some(),
-            "{:?} is not a function", function);*/
+        debug_assert!(self.functions.borrow().values().find(|value| **value == function).is_some(),
+            "{:?} is not a function", function);
         function
     }
 
@@ -332,7 +332,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     }
 
     fn get_fn(&self, instance: Instance<'tcx>) -> RValue<'gcc> {
-        let func = get_fn(self, instance, false);
+        let func = get_fn(self, instance);
         *self.current_func.borrow_mut() = Some(func);
         unsafe { std::mem::transmute(func) }
     }
@@ -345,7 +345,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                 self.intrinsics.borrow()[func_name].clone()
             }
             else {
-                get_fn(self, instance, false)
+                get_fn(self, instance)
             };
         let ptr = func.get_address(None);
 
@@ -386,8 +386,6 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         let func =
             match tcx.lang_items().eh_personality() {
                 Some(def_id) if !wants_msvc_seh(self.sess()) => {
-                    // FIXME: this create an instance into self.functions and prevent the creating
-                    // of the function defined in std.
                     let instance =
                         ty::Instance::resolve(
                             tcx,
@@ -400,45 +398,19 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                     let symbol_name = tcx.symbol_name(instance).name;
                     let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
                     self.linkage.set(FunctionType::Extern);
-                    let func = self.declare_fn(symbol_name, &fn_abi, false);
-                    //func.add_attribute(FnAttribute::Weak);
-
-                    /*let block = func.new_block("eh_personality_block");
-                    // NOTE: it seems this function is overwritten by the standard library, so just
-                    // return a dummy value in this version.
-                    let zero = self.context.new_rvalue_zero(self.type_u32());
-                    block.end_with_return(None, zero);*/
-
-                    //*self.current_func.borrow_mut() = Some(func);
+                    let func = self.declare_fn(symbol_name, &fn_abi);
                     let func: RValue<'gcc> = unsafe { std::mem::transmute(func) };
                     func
-                    /*self.get_fn(
-                        ty::Instance::resolve(
-                            tcx,
-                            ty::ParamEnv::reveal_all(),
-                            def_id,
-                            tcx.intern_substs(&[]),
-                        )
-                        .unwrap().unwrap(),
-                    )*/
                 },
                 _ => {
-                    let name = if wants_msvc_seh(self.sess()) {
-                        "__CxxFrameHandler3"
-                    } else {
-                        "rust_eh_personality"
-                    };
+                    let name =
+                        if wants_msvc_seh(self.sess()) {
+                            "__CxxFrameHandler3"
+                        }
+                        else {
+                            "rust_eh_personality"
+                        };
                     let func = self.declare_func(name, self.type_i32(), &[], true);
-                    //*self.current_func.borrow_mut() = Some(func);
-                    // NOTE: this function is created multiple times and is overwritten by the
-                    // standard library, so mark it as weak.
-                    //func.add_attribute(FnAttribute::Weak);
-                    //self.functions.borrow_mut().insert(name.to_string(), func);
-                    /*let block = func.new_block("eh_personality_block");
-                    // NOTE: it seems this function is overwritten by the standard library, so just
-                    // return a dummy value in this version.
-                    let zero = self.context.new_rvalue_zero(self.type_i32());
-                    block.end_with_return(None, zero);*/
                     unsafe { std::mem::transmute(func) }
                 }
             };

src/declare.rs

@@ -40,7 +40,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 
     pub fn declare_func(&self, name: &str, return_type: Type<'gcc>, params: &[Type<'gcc>], variadic: bool) -> Function<'gcc> {
         self.linkage.set(FunctionType::Extern);
-        declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, params, variadic, true)
+        declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, params, variadic)
     }
 
     pub fn declare_global(&self, name: &str, ty: Type<'gcc>, global_kind: GlobalKind, is_tls: bool, link_section: Option<Symbol>) -> LValue<'gcc> {
@@ -69,27 +69,17 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         let return_type = self.type_i32();
         let variadic = false;
         self.linkage.set(FunctionType::Exported);
-        let func = declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, &[self.type_i32(), const_string], variadic, false);
+        let func = declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, &[self.type_i32(), const_string], variadic);
         // NOTE: it is needed to set the current_func here as well, because get_fn() is not called
         // for the main function.
         *self.current_func.borrow_mut() = Some(func);
         // FIXME(antoyo): this is a wrong cast. That requires changing the compiler API.
         unsafe { std::mem::transmute(func) }
     }
 
-    pub fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, dont_cache: bool) -> Function<'gcc> {
+    pub fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Function<'gcc> {
         let (return_type, params, variadic, on_stack_param_indices) = fn_abi.gcc_type(self);
-        /*static mut COUNTER: i32 = 0;
-        if name.contains("personality") {
-            println!("{}: {}", name, skip_cache);
-            unsafe {
-                COUNTER += 1;
-                if COUNTER == 6 {
-                    panic!("{}", name);
-                }
-            }
-        }*/
-        let func = declare_raw_fn(self, name, () /*fn_abi.llvm_cconv()*/, return_type, &params, variadic, dont_cache);
+        let func = declare_raw_fn(self, name, () /*fn_abi.llvm_cconv()*/, return_type, &params, variadic);
         self.on_stack_function_params.borrow_mut().insert(func, on_stack_param_indices);
         func
     }
@@ -108,7 +98,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 ///
 /// If there’s a value with the same name already declared, the function will
 /// update the declaration and return existing Value instead.
-fn declare_raw_fn<'gcc>(cx: &CodegenCx<'gcc, '_>, name: &str, _callconv: () /*llvm::CallConv*/, return_type: Type<'gcc>, param_types: &[Type<'gcc>], variadic: bool, dont_cache: bool) -> Function<'gcc> {
+fn declare_raw_fn<'gcc>(cx: &CodegenCx<'gcc, '_>, name: &str, _callconv: () /*llvm::CallConv*/, return_type: Type<'gcc>, param_types: &[Type<'gcc>], variadic: bool) -> Function<'gcc> {
     if name.starts_with("llvm.") {
         let intrinsic = llvm::intrinsic(name, cx);
         cx.intrinsics.borrow_mut().insert(name.to_string(), intrinsic);
@@ -123,9 +113,7 @@ fn declare_raw_fn<'gcc>(cx: &CodegenCx<'gcc, '_>, name: &str, _callconv: () /*ll
                 .map(|(index, param)| cx.context.new_parameter(None, *param, &format!("param{}", index))) // TODO(antoyo): set name.
                 .collect();
             let func = cx.context.new_function(None, cx.linkage.get(), return_type, &params, mangle_name(name), variadic);
-            //if !dont_cache {
-                cx.functions.borrow_mut().insert(name.to_string(), func);
-            //}
+            cx.functions.borrow_mut().insert(name.to_string(), func);
             func
         };
 

src/intrinsic/mod.rs

@@ -1118,9 +1118,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 }
 
 fn try_intrinsic<'a, 'b, 'gcc, 'tcx>(bx: &'b mut Builder<'a, 'gcc, 'tcx>, try_func: RValue<'gcc>, data: RValue<'gcc>, catch_func: RValue<'gcc>, dest: RValue<'gcc>) {
-    // NOTE: the `|| true` here is to use the panic=abort strategy with panic=unwind too
     if bx.sess().panic_strategy() == PanicStrategy::Abort {
-        // TODO(bjorn3): Properly implement unwinding and remove the `|| true` once this is done.
         bx.call(bx.type_void(), try_func, &[data], None);
         // Return 0 unconditionally from the intrinsic call;
         // we can never unwind.
@@ -1238,7 +1236,7 @@ fn get_rust_try_fn<'a, 'gcc, 'tcx>(cx: &'a CodegenCx<'gcc, 'tcx>, codegen: &mut
     )));
     // `unsafe fn(unsafe fn(*mut i8) -> (), *mut i8, unsafe fn(*mut i8, *mut i8) -> ()) -> i32`
     let rust_fn_sig = ty::Binder::dummy(cx.tcx.mk_fn_sig(
-        [try_fn_ty, i8p, catch_fn_ty].into_iter(),
+        [try_fn_ty, i8p, catch_fn_ty].iter(),
         &tcx.types.i32,
         false,
         rustc_hir::Unsafety::Unsafe,
@@ -1256,7 +1254,7 @@ fn gen_fn<'a, 'gcc, 'tcx>(cx: &'a CodegenCx<'gcc, 'tcx>, name: &str, rust_fn_sig
     let (typ, _, _, _) = fn_abi.gcc_type(cx);
     // FIXME(eddyb) find a nicer way to do this.
     cx.linkage.set(FunctionType::Internal);
-    let func = cx.declare_fn(name, fn_abi, false);
+    let func = cx.declare_fn(name, fn_abi);
     let func_val = unsafe { std::mem::transmute(func) };
     cx.set_frame_pointer_type(func_val);
     cx.apply_target_cpu_attr(func_val);

src/mono_item.rs

@@ -35,7 +35,7 @@ impl<'gcc, 'tcx> PreDefineMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
 
         let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
         self.linkage.set(base::linkage_to_gcc(linkage));
-        let decl = self.declare_fn(symbol_name, &fn_abi, false);
+        let decl = self.declare_fn(symbol_name, &fn_abi);
         //let attrs = self.tcx.codegen_fn_attrs(instance.def_id());
 
         attributes::from_fn_attrs(self, decl, instance);