Auto merge of rust-lang#15419 - HKalbasi:mir, r=HKalbasi

Add mir lower support for tuple destructing assignment

And some other changes in mir eval

Author: bors

crates/base-db/src/fixture.rs

@@ -130,6 +130,7 @@ impl ChangeFixture {
         let mut default_crate_root: Option<FileId> = None;
         let mut default_target_data_layout: Option<String> = None;
         let mut default_cfg = CfgOptions::default();
+        let mut default_env = Env::new_for_test_fixture();
 
         let mut file_set = FileSet::default();
         let mut current_source_root_kind = SourceRootKind::Local;
@@ -200,6 +201,7 @@ impl ChangeFixture {
                 assert!(default_crate_root.is_none());
                 default_crate_root = Some(file_id);
                 default_cfg = meta.cfg;
+                default_env.extend(meta.env.iter().map(|(x, y)| (x.to_owned(), y.to_owned())));
                 default_target_data_layout = meta.target_data_layout;
             }
 
@@ -220,7 +222,7 @@ impl ChangeFixture {
                 None,
                 default_cfg,
                 Default::default(),
-                Env::new_for_test_fixture(),
+                default_env,
                 false,
                 CrateOrigin::Local { repo: None, name: None },
                 default_target_data_layout

crates/base-db/src/input.rs

@@ -686,6 +686,12 @@ impl fmt::Display for Edition {
     }
 }
 
+impl Extend<(String, String)> for Env {
+    fn extend<T: IntoIterator<Item = (String, String)>>(&mut self, iter: T) {
+        self.entries.extend(iter);
+    }
+}
+
 impl FromIterator<(String, String)> for Env {
     fn from_iter<T: IntoIterator<Item = (String, String)>>(iter: T) -> Self {
         Env { entries: FromIterator::from_iter(iter) }

crates/hir-ty/src/consteval/tests.rs

@@ -1203,6 +1203,27 @@ fn destructing_assignment() {
         "#,
         5,
     );
+    check_number(
+        r#"
+    const GOAL: u8 = {
+        let (mut a, mut b) = (2, 5);
+        (a, b) = (b, a);
+        a * 10 + b
+    };
+        "#,
+        52,
+    );
+    check_number(
+        r#"
+    struct Point { x: i32, y: i32 }
+    const GOAL: i32 = {
+        let mut p = Point { x: 5, y: 6 };
+        (p.x, _) = (p.y, p.x);
+        p.x * 10 + p.y
+    };
+        "#,
+        66,
+    );
 }
 
 #[test]
@@ -1432,6 +1453,30 @@ fn from_trait() {
     );
 }
 
+#[test]
+fn closure_clone() {
+    check_number(
+        r#"
+//- minicore: clone, fn
+struct S(u8);
+
+impl Clone for S(u8) {
+    fn clone(&self) -> S {
+        S(self.0 + 5)
+    }
+}
+
+const GOAL: u8 = {
+    let s = S(3);
+    let cl = move || s;
+    let cl = cl.clone();
+    cl().0
+}
+    "#,
+        8,
+    );
+}
+
 #[test]
 fn builtin_derive_macro() {
     check_number(
@@ -2396,14 +2441,14 @@ fn const_loop() {
 fn const_transfer_memory() {
     check_number(
         r#"
-    //- minicore: slice, index, coerce_unsized
+    //- minicore: slice, index, coerce_unsized, option
     const A1: &i32 = &1;
     const A2: &i32 = &10;
     const A3: [&i32; 3] = [&1, &2, &100];
-    const A4: (i32, &i32) = (1, &1000);
-    const GOAL: i32 = *A1 + *A2 + *A3[2] + *A4.1;
+    const A4: (i32, &i32, Option<&i32>) = (1, &1000, Some(&10000));
+    const GOAL: i32 = *A1 + *A2 + *A3[2] + *A4.1 + *A4.2.unwrap_or(&5);
     "#,
-        1111,
+        11111,
     );
 }
 

crates/hir-ty/src/mir/eval.rs

@@ -2007,7 +2007,28 @@ impl Evaluator<'_> {
                     }
                 }
                 AdtId::UnionId(_) => (),
-                AdtId::EnumId(_) => (),
+                AdtId::EnumId(e) => {
+                    if let Some((variant, layout)) = detect_variant_from_bytes(
+                        &layout,
+                        self.db,
+                        self.trait_env.clone(),
+                        self.read_memory(addr, layout.size.bytes_usize())?,
+                        e,
+                    ) {
+                        let ev = EnumVariantId { parent: e, local_id: variant };
+                        for (i, (_, ty)) in self.db.field_types(ev.into()).iter().enumerate() {
+                            let offset = layout.fields.offset(i).bytes_usize();
+                            let ty = ty.clone().substitute(Interner, subst);
+                            self.patch_addresses(
+                                patch_map,
+                                old_vtable,
+                                addr.offset(offset),
+                                &ty,
+                                locals,
+                            )?;
+                        }
+                    }
+                }
             },
             TyKind::Tuple(_, subst) => {
                 for (id, ty) in subst.iter(Interner).enumerate() {

crates/hir-ty/src/mir/eval/shim.rs

@@ -136,7 +136,10 @@ impl Evaluator<'_> {
                     not_supported!("wrong generic arg kind for clone");
                 };
                 // Clone has special impls for tuples and function pointers
-                if matches!(self_ty.kind(Interner), TyKind::Function(_) | TyKind::Tuple(..)) {
+                if matches!(
+                    self_ty.kind(Interner),
+                    TyKind::Function(_) | TyKind::Tuple(..) | TyKind::Closure(..)
+                ) {
                     self.exec_clone(def, args, self_ty.clone(), locals, destination, span)?;
                     return Ok(true);
                 }
@@ -167,32 +170,26 @@ impl Evaluator<'_> {
                 return destination
                     .write_from_interval(self, Interval { addr, size: destination.size });
             }
+            TyKind::Closure(id, subst) => {
+                let [arg] = args else {
+                    not_supported!("wrong arg count for clone");
+                };
+                let addr = Address::from_bytes(arg.get(self)?)?;
+                let (closure_owner, _) = self.db.lookup_intern_closure((*id).into());
+                let infer = self.db.infer(closure_owner);
+                let (captures, _) = infer.closure_info(id);
+                let layout = self.layout(&self_ty)?;
+                let ty_iter = captures.iter().map(|c| c.ty(subst));
+                self.exec_clone_for_fields(ty_iter, layout, addr, def, locals, destination, span)?;
+            }
             TyKind::Tuple(_, subst) => {
                 let [arg] = args else {
                     not_supported!("wrong arg count for clone");
                 };
                 let addr = Address::from_bytes(arg.get(self)?)?;
                 let layout = self.layout(&self_ty)?;
-                for (i, ty) in subst.iter(Interner).enumerate() {
-                    let ty = ty.assert_ty_ref(Interner);
-                    let size = self.layout(ty)?.size.bytes_usize();
-                    let tmp = self.heap_allocate(self.ptr_size(), self.ptr_size())?;
-                    let arg = IntervalAndTy {
-                        interval: Interval { addr: tmp, size: self.ptr_size() },
-                        ty: TyKind::Ref(Mutability::Not, static_lifetime(), ty.clone())
-                            .intern(Interner),
-                    };
-                    let offset = layout.fields.offset(i).bytes_usize();
-                    self.write_memory(tmp, &addr.offset(offset).to_bytes())?;
-                    self.exec_clone(
-                        def,
-                        &[arg],
-                        ty.clone(),
-                        locals,
-                        destination.slice(offset..offset + size),
-                        span,
-                    )?;
-                }
+                let ty_iter = subst.iter(Interner).map(|ga| ga.assert_ty_ref(Interner).clone());
+                self.exec_clone_for_fields(ty_iter, layout, addr, def, locals, destination, span)?;
             }
             _ => {
                 self.exec_fn_with_args(
@@ -209,6 +206,37 @@ impl Evaluator<'_> {
         Ok(())
     }
 
+    fn exec_clone_for_fields(
+        &mut self,
+        ty_iter: impl Iterator<Item = Ty>,
+        layout: Arc<Layout>,
+        addr: Address,
+        def: FunctionId,
+        locals: &Locals,
+        destination: Interval,
+        span: MirSpan,
+    ) -> Result<()> {
+        for (i, ty) in ty_iter.enumerate() {
+            let size = self.layout(&ty)?.size.bytes_usize();
+            let tmp = self.heap_allocate(self.ptr_size(), self.ptr_size())?;
+            let arg = IntervalAndTy {
+                interval: Interval { addr: tmp, size: self.ptr_size() },
+                ty: TyKind::Ref(Mutability::Not, static_lifetime(), ty.clone()).intern(Interner),
+            };
+            let offset = layout.fields.offset(i).bytes_usize();
+            self.write_memory(tmp, &addr.offset(offset).to_bytes())?;
+            self.exec_clone(
+                def,
+                &[arg],
+                ty,
+                locals,
+                destination.slice(offset..offset + size),
+                span,
+            )?;
+        }
+        Ok(())
+    }
+
     fn exec_alloc_fn(
         &mut self,
         alloc_fn: &str,
@@ -473,6 +501,38 @@ impl Evaluator<'_> {
                 self.write_memory_using_ref(destination.addr, destination.size)?.fill(0);
                 Ok(())
             }
+            "getenv" => {
+                let [name] = args else {
+                    return Err(MirEvalError::TypeError("libc::write args are not provided"));
+                };
+                let mut name_buf = vec![];
+                let name = {
+                    let mut index = Address::from_bytes(name.get(self)?)?;
+                    loop {
+                        let byte = self.read_memory(index, 1)?[0];
+                        index = index.offset(1);
+                        if byte == 0 {
+                            break;
+                        }
+                        name_buf.push(byte);
+                    }
+                    String::from_utf8_lossy(&name_buf)
+                };
+                let value = self.db.crate_graph()[self.crate_id].env.get(&name);
+                match value {
+                    None => {
+                        // Write null as fail
+                        self.write_memory_using_ref(destination.addr, destination.size)?.fill(0);
+                    }
+                    Some(mut value) => {
+                        value.push('\0');
+                        let addr = self.heap_allocate(value.len(), 1)?;
+                        self.write_memory(addr, value.as_bytes())?;
+                        self.write_memory(destination.addr, &addr.to_bytes())?;
+                    }
+                }
+                Ok(())
+            }
             _ => not_supported!("unknown external function {as_str}"),
         }
     }

crates/hir-ty/src/mir/eval/tests.rs

@@ -729,6 +729,48 @@ fn main() {
     )
 }
 
+#[test]
+fn posix_getenv() {
+    check_pass(
+        r#"
+//- /main.rs env:foo=bar
+
+type c_char = u8;
+
+extern "C" {
+    pub fn getenv(s: *const c_char) -> *mut c_char;
+}
+
+fn should_not_reach() {
+    _ // FIXME: replace this function with panic when that works
+}
+
+fn main() {
+    let result = getenv(b"foo\0" as *const _);
+    if *result != b'b' {
+        should_not_reach();
+    }
+    let result = (result as usize + 1) as *const c_char;
+    if *result != b'a' {
+        should_not_reach();
+    }
+    let result = (result as usize + 1) as *const c_char;
+    if *result != b'r' {
+        should_not_reach();
+    }
+    let result = (result as usize + 1) as *const c_char;
+    if *result != 0 {
+        should_not_reach();
+    }
+    let result = getenv(b"not found\0" as *const _);
+    if result as usize != 0 {
+        should_not_reach();
+    }
+}
+"#,
+    );
+}
+
 #[test]
 fn posix_tls() {
     check_pass(

crates/hir-ty/src/mir/lower.rs

@@ -1244,6 +1244,41 @@ impl<'ctx> MirLowerCtx<'ctx> {
         }
     }
 
+    fn lower_destructing_assignment(
+        &mut self,
+        mut current: BasicBlockId,
+        lhs: ExprId,
+        rhs: Place,
+        span: MirSpan,
+    ) -> Result<Option<BasicBlockId>> {
+        match &self.body.exprs[lhs] {
+            Expr::Tuple { exprs, is_assignee_expr: _ } => {
+                for (i, expr) in exprs.iter().enumerate() {
+                    let Some(c) = self.lower_destructing_assignment(
+                        current,
+                        *expr,
+                        rhs.project(ProjectionElem::TupleOrClosureField(i)),
+                        span,
+                    )? else {
+                        return Ok(None);
+                    };
+                    current = c;
+                }
+                Ok(Some(current))
+            }
+            Expr::Underscore => Ok(Some(current)),
+            _ => {
+                let Some((lhs_place, current)) =
+                    self.lower_expr_as_place(current, lhs, false)?
+                else {
+                    return Ok(None);
+                };
+                self.push_assignment(current, lhs_place, Operand::Copy(rhs).into(), span);
+                Ok(Some(current))
+            }
+        }
+    }
+
     fn lower_assignment(
         &mut self,
         current: BasicBlockId,
@@ -1259,6 +1294,15 @@ impl<'ctx> MirLowerCtx<'ctx> {
         if matches!(&self.body.exprs[lhs], Expr::Underscore) {
             return Ok(Some(current));
         }
+        if matches!(
+            &self.body.exprs[lhs],
+            Expr::Tuple { .. } | Expr::RecordLit { .. } | Expr::Call { .. }
+        ) {
+            let temp = self.temp(self.expr_ty_after_adjustments(rhs), current, rhs.into())?;
+            let temp = Place::from(temp);
+            self.push_assignment(current, temp.clone(), rhs_op.into(), span);
+            return self.lower_destructing_assignment(current, lhs, temp, span);
+        }
         let Some((lhs_place, current)) =
             self.lower_expr_as_place(current, lhs, false)?
         else {