WIP: fix endianness of non-native 128-bit integers

Author: antoyo

.github/workflows/m68k.yml

@@ -140,12 +140,8 @@ jobs:
 
     - name: Build
       run: |
-        ./y.sh prepare --only-libcore
-        # TODO: move into prepare command under a flag --cross-patches?
-        pushd build_sysroot/sysroot_src
-        git am ../../cross_patches/*.patch
-        popd
-        ./build.sh
+        ./y.sh prepare --only-libcore --cross
+        ./y.sh build --target m68k-unknown-linux-gnu
         cargo test
         ./clean_all.sh
 

build_system/src/build.rs

@@ -11,7 +11,7 @@ use std::path::Path;
 struct BuildArg {
     codegen_release_channel: bool,
     sysroot_release_channel: bool,
-    features: Vec<String>,
+    flags: Vec<String>,
     gcc_path: String,
 }
 
@@ -30,12 +30,22 @@ impl BuildArg {
                 "--release" => build_arg.codegen_release_channel = true,
                 "--release-sysroot" => build_arg.sysroot_release_channel = true,
                 "--no-default-features" => {
-                    build_arg.features.push("--no-default-features".to_string());
+                    build_arg.flags.push("--no-default-features".to_string());
+                }
+                "--target" => {
+                    if let Some(arg) = args.next() {
+                        build_arg.flags.push("--target".to_string());
+                        build_arg.flags.push(arg.as_str().into());
+                    } else {
+                        return Err(
+                            "Expected a value after `--target`, found nothing".to_string()
+                        );
+                    }
                 }
                 "--features" => {
                     if let Some(arg) = args.next() {
-                        build_arg.features.push("--features".to_string());
-                        build_arg.features.push(arg.as_str().into());
+                        build_arg.flags.push("--features".to_string());
+                        build_arg.flags.push(arg.as_str().into());
                     } else {
                         return Err(
                             "Expected a value after `--features`, found nothing".to_string()
@@ -61,6 +71,7 @@ impl BuildArg {
     --release-sysroot      : Build sysroot in release mode
     --no-default-features  : Add `--no-default-features` flag
     --features [arg]       : Add a new feature [arg]
+    --target [arg]         : Set the target to [arg]
     --help                 : Show this help
 "#
         )
@@ -147,8 +158,6 @@ fn build_sysroot(
                 &"build",
                 &"--target",
                 &target_triple,
-                &"--features",
-                &"compiler_builtins/c",
             ],
             None,
             Some(env),
@@ -196,9 +205,9 @@ fn build_codegen(args: &BuildArg) -> Result<(), String> {
     } else {
         env.insert("CHANNEL".to_string(), "debug".to_string());
     }
-    let ref_features = args.features.iter().map(|s| s.as_str()).collect::<Vec<_>>();
-    for feature in &ref_features {
-        command.push(feature);
+    let flags = args.flags.iter().map(|s| s.as_str()).collect::<Vec<_>>();
+    for flag in &flags {
+        command.push(flag);
     }
     run_command_with_output_and_env(&command, None, Some(&env))?;
 

src/context.rs

@@ -20,6 +20,7 @@ use rustc_target::abi::{call::FnAbi, HasDataLayout, PointeeInfo, Size, TargetDat
 use rustc_target::spec::{HasTargetSpec, Target, TlsModel};
 
 use crate::callee::get_fn;
+use crate::common::SignType;
 
 #[derive(Clone)]
 pub struct FuncSig<'gcc> {
@@ -187,8 +188,8 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         let ulonglong_type = context.new_c_type(CType::ULongLong);
         let sizet_type = context.new_c_type(CType::SizeT);
 
-        let isize_type = context.new_c_type(CType::Int);
-        let usize_type = context.new_c_type(CType::UInt);
+        let usize_type = sizet_type;
+        let isize_type = usize_type;
         let bool_type = context.new_type::<bool>();
 
         // TODO(antoyo): only have those assertions on x86_64.
@@ -212,7 +213,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             functions.insert(builtin.to_string(), context.get_builtin_function(builtin));
         }
 
-        Self {
+        let mut cx = Self {
             check_overflow,
             codegen_unit,
             context,
@@ -274,7 +275,10 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             pointee_infos: Default::default(),
             structs_as_pointer: Default::default(),
             cleanup_blocks: Default::default(),
-        }
+        };
+        // TODO(antoyo): instead of doing this, add SsizeT to libgccjit.
+        cx.isize_type = usize_type.to_signed(&cx);
+        cx
     }
 
     pub fn rvalue_as_function(&self, value: RValue<'gcc>) -> Function<'gcc> {

src/int.rs

@@ -8,6 +8,7 @@ use gccjit::{ComparisonOp, FunctionType, RValue, ToRValue, Type, UnaryOp, Binary
 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc_codegen_ssa::traits::{BackendTypes, BaseTypeMethods, BuilderMethods, OverflowOp};
 use rustc_middle::ty::Ty;
+use rustc_target::abi::Endian;
 
 use crate::builder::ToGccComp;
 use crate::{builder::Builder, common::{SignType, TypeReflection}, context::CodegenCx};
@@ -792,10 +793,16 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     }
 
     fn from_low_high(&self, typ: Type<'gcc>, low: i64, high: i64) -> RValue<'gcc> {
+        let (first, last) =
+            match self.sess().target.options.endian {
+                Endian::Little => (low, high),
+                Endian::Big => (high, low),
+            };
+
         let native_int_type = typ.dyncast_array().expect("get element type");
         let values = [
-            self.context.new_rvalue_from_long(native_int_type, low),
-            self.context.new_rvalue_from_long(native_int_type, high),
+            self.context.new_rvalue_from_long(native_int_type, first),
+            self.context.new_rvalue_from_long(native_int_type, last),
         ];
         self.context.new_array_constructor(None, typ, &values)
     }

tests/lang_tests_common.rs

@@ -74,7 +74,7 @@ pub fn main_inner(profile: Profile) {
             }
             // Test command 2: run `tempdir/x`.
             let vm_parent_dir = "/home/bouanto/Ordinateur/VirtualMachines";
-            let vm_dir = "debian-m68k-root-img/";
+            let vm_dir = "debian-m68k-root/";
             let exe_filename = exe.file_name().unwrap();
             let vm_exe_path = PathBuf::from(vm_parent_dir).join(vm_dir).join("home").join(exe_filename);
             // FIXME: panicking here makes the test pass.