build symbol table

lang/src/tokeniser.asm

@@ -27,6 +27,9 @@ global unwrap_token
 global peek_expect_token
 global peek_lexeme
 
+global tokeniser_get_cursor
+global tokeniser_set_cursor
+
 ;; =============================
 ;; Tokeniser functions
 ;; =============================
@@ -583,3 +586,11 @@ peek_lexeme:
     pop rax
     pop rbp
     ret
+
+tokeniser_get_cursor:
+    mov rax, [rel cursor]
+    ret
+
+tokeniser_set_cursor:
+    mov [rel cursor], rdi
+    ret

lang/src/tokeniser.inc

@@ -34,6 +34,16 @@ LEXEMES:
     dq LEX_VOID
     dq LEX_SLASH
     dq LEX_STAR
+    dq LEX_U8
+    dq LEX_I8
+    dq LEX_U16
+    dq LEX_I16
+    dq LEX_U64
+    dq LEX_I64
+    dq LEX_USIZE
+    dq LEX_ISIZE
+    dq LEX_F32
+    dq LEX_F64
 
 align 8
 TOKENS:
@@ -70,6 +80,16 @@ TOKENS:
     db TOKEN_VOID                  ;; 30
     db TOKEN_SLASH                 ;; 31
     db TOKEN_STAR                  ;; 32
+    db TOKEN_U8                    ;; 33
+    db TOKEN_I8                    ;; 34
+    db TOKEN_U16                   ;; 35
+    db TOKEN_I16                   ;; 36
+    db TOKEN_U64                   ;; 37
+    db TOKEN_I64                   ;; 38
+    db TOKEN_USIZE                 ;; 39
+    db TOKEN_ISIZE                 ;; 40
+    db TOKEN_F32                   ;; 41
+    db TOKEN_F64                   ;; 42
 
 align 8
 LEXEME_LENS:
@@ -106,9 +126,19 @@ LEXEME_LENS:
     dq LEX_VOID_len
     dq LEX_SLASH_len
     dq LEX_STAR_len
+    dq LEX_U8_len
+    dq LEX_I8_len
+    dq LEX_U16_len
+    dq LEX_I16_len
+    dq LEX_U64_len
+    dq LEX_I64_len
+    dq LEX_USIZE_len
+    dq LEX_ISIZE_len
+    dq LEX_F32_len
+    dq LEX_F64_len
 
 align 8
-NUM_LEXEMES: dq 33
+NUM_LEXEMES: dq 43
 
     LEX_NOT_A_LEXEME db "<not a lexeme>", 0
     LEX_LET db "let"
@@ -175,6 +205,26 @@ NUM_LEXEMES: dq 33
     LEX_SLASH_len equ $ - LEX_SLASH
     LEX_STAR db "*"
     LEX_STAR_len equ $ - LEX_STAR
+    LEX_U8 db "u8"
+    LEX_U8_len equ $ - LEX_U8
+    LEX_I8 db "i8"
+    LEX_I8_len equ $ - LEX_I8
+    LEX_U16 db "u16"
+    LEX_U16_len equ $ - LEX_U16
+    LEX_I16 db "i16"
+    LEX_I16_len equ $ - LEX_I16
+    LEX_U64 db "u64"
+    LEX_U64_len equ $ - LEX_U64
+    LEX_I64 db "i64"
+    LEX_I64_len equ $ - LEX_I64
+    LEX_USIZE db "usize"
+    LEX_USIZE_len equ $ - LEX_USIZE
+    LEX_ISIZE db "isize"
+    LEX_ISIZE_len equ $ - LEX_ISIZE
+    LEX_F32 db "f32"
+    LEX_F32_len equ $ - LEX_F32
+    LEX_F64 db "f64"
+    LEX_F64_len equ $ - LEX_F64
     LEX_IDENT db "<identifier>"
     LEX_IDENT_len equ $ - LEX_IDENT
     LEX_NUMBER db "<number>"
@@ -218,8 +268,18 @@ NUM_LEXEMES: dq 33
     TOKEN_VOID      equ 30 ; :u8
     TOKEN_SLASH     equ 31 ; :u8
     TOKEN_STAR      equ 32 ; :u8
-    TOKEN_IDENT     equ 33 ; :u8
-    TOKEN_NUMBER    equ 34 ; :u8
-    TOKEN_STRING    equ 35 ; :u8
-    TOKEN_COMMENT   equ 36 ; :u8
+    TOKEN_U8        equ 33 ; :u8
+    TOKEN_I8        equ 34 ; :u8
+    TOKEN_U16       equ 35 ; :u8
+    TOKEN_I16       equ 36 ; :u8
+    TOKEN_U64       equ 37 ; :u8
+    TOKEN_I64       equ 38 ; :u8
+    TOKEN_USIZE     equ 39 ; :u8
+    TOKEN_ISIZE     equ 40 ; :u8
+    TOKEN_F32       equ 41 ; :u8
+    TOKEN_F64       equ 42 ; :u8
+    TOKEN_IDENT     equ 43 ; :u8
+    TOKEN_NUMBER    equ 44 ; :u8
+    TOKEN_STRING    equ 45 ; :u8
+    TOKEN_COMMENT   equ 46 ; :u8
     ;; end-consts

lang/src/vec.asm

@@ -18,6 +18,7 @@ global vec_drop_last
 global vec_swap
 global vec_remove
 global vec_get
+global vec_get_or
 global vec_drop
 global vec_find
 global vec_insert
@@ -104,6 +105,29 @@ vec_init_with:
     pop rbp
     ret
 
+;; rdi: pointer to Vec struct
+;; rsi: index
+;; rdx: pointer to default value
+;; fn vec_get(vec: *mut Vec, index: usize, default: *mut u8) -> *mut u8
+vec_get_or:
+    push rbp
+    mov rbp, rsp
+    ; if (index >= vec.len) panic();
+    mov rax, [rdi + 8]    ; len
+    cmp rsi, rax
+    jge .default
+    ; return &mut vec.data[index * vec.item_size];
+    mov rax, [rdi + 24]   ; item_size
+    mul rsi         ; index * item_size
+    mov rsi, [rdi]       ; data
+    add rax, rsi         ; data + index * item_size
+    pop rbp
+    ret
+.default:
+    mov rax, rdx
+    pop rbp
+    ret
+
 ;; rdi: pointer to Vec struct
 ;; rsi: index
 ;; fn vec_get(vec: *mut Vec, index: usize) -> *mut u8
@@ -520,8 +544,8 @@ vec_binary_search_by:
 
     mov rax, [rdi + 8]          ; len
     dec rax                     ; high
-    mov qword [rsp + 0x20], 0         ; low
-    mov [rsp + 0x28], rax       ; mid
+    mov qword [rsp + 0x20], 0   ; low
+    mov qword [rsp + 0x28], 0   ; mid
     mov [rsp + 0x30], rax       ; high
     mov rax, [rdi + 24]         ; item_size
     mov [rsp + 0x38], rax       ; item_size

lang/tests/ast.rs

@@ -1,3 +1,5 @@
+#![feature(debug_closure_helpers)]
+
 #[path = "shared/shared.rs"]
 mod util;
 
@@ -17,46 +19,129 @@ fn main() {
 
     let src = b"3 + 4";
 
-    fn print_ast(src: &[u8], parser: impl FnOnce(&mut Ast)) {
+    fn print_ast(src: &[u8], parser: impl FnOnce(&mut Ast) -> u64) {
         unsafe {
             tokeniser_init_buf(src.as_ptr(), src.len());
             let mut ast = Ast {
                 nodes: util::vec::Vec::new(),
             };
             let expr_id = parser(&mut ast);
+            eprintln!("Parsed expression ID: {}", expr_id);
             println!("{:#}", &ast);
+
+            // unsafe extern "C" fn visit_node(_this: *mut (), ast: *mut Ast, node_id: u64) {
+            //     let ast = unsafe { &*ast };
+            //     let node = ast.nodes.get(node_id as usize).unwrap();
+            //     eprintln!("Visiting node {node_id}: {node}");
+            // }
+
+            // util::defs::ast_walk_for_each(&mut ast, expr_id, core::ptr::null_mut(), visit_node);
+
+            let mut symtable = core::mem::MaybeUninit::<util::defs::SymbolTable>::uninit();
+            util::defs::ast_build_symtable(&mut ast, expr_id, &mut symtable);
+            let symtable = symtable.assume_init();
+            use util::DisplayedSliceExt;
+            println!(
+                "Symbol Table: {:#?}",
+                symtable.symtable.as_slice().displayed()
+            );
         };
     }
 
-    print_ast(b"3 + 4", |ast| unsafe {
-        parse_expr(ast);
-    });
-    print_ast(b"fn main() -> void { return 1 + 2; }", |ast| unsafe {
-        parse_func(ast);
-    });
-    print_ast(b"fn main() -> void { return (1 + (2)); }", |ast| unsafe {
-        parse_func(ast);
-    });
+    // print_ast(b"3 + 4", |ast| unsafe { parse_expr(ast) });
+    // print_ast(b"fn main() -> void { return 1 + 2; }", |ast| unsafe {
+    //     parse_func(ast)
+    // });
+    // print_ast(b"fn main() -> void { return (1 + (2)); }", |ast| unsafe {
+    //     parse_func(ast)
+    // });
+    // print_ast(
+    //     b"fn main() -> void { return (1 + (2 * 3)) / 4; }",
+    //     |ast| unsafe { parse_func(ast) },
+    // );
+    // print_ast(b"fn main() -> void { return 1 + 2 * 3; }", |ast| unsafe {
+    //     parse_func(ast)
+    // });
+
+    // print_ast(b"fn main() -> void { let x: u32 = 4; }", |ast| unsafe {
+    //     parse_func(ast)
+    // });
     print_ast(
-        b"fn main() -> void { return (1 + (2 * 3)) / 4; }",
-        |ast| unsafe {
-            parse_func(ast);
-        },
+        b"fn main(a: u32) -> void { let x: u32 = a + 4; }",
+        |ast| unsafe { parse_func(ast) },
+    );
+    print_ast(
+        b"fn main(a: u32) -> void {
+let x: u32 = a + 4;
+let y: *u32 = &x;
+return *y;
+}",
+        |ast| unsafe { parse_func(ast) },
     );
-    print_ast(b"fn main() -> void { return 1 + 2 * 3; }", |ast| unsafe {
-        parse_func(ast);
-    });
 }
 
 impl std::fmt::Display for AstNode {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         use util::defs::{
-            BinaryExpr, AST_BINARY_OP, AST_BLOCK, AST_FUNCTION, AST_NUMBER, AST_RETURN_STATEMENT,
+            BinaryExpr, AST_ADDRESS_OF, AST_ARG, AST_ASSIGNMENT, AST_BINARY_OP, AST_BLOCK,
+            AST_DEREF, AST_FUNCTION, AST_NUMBER, AST_PLACE_TO_VALUE, AST_RETURN_STATEMENT,
+            AST_VALUE_TO_PLACE, AST_VAR_DECL, AST_VAR_REF,
         };
-        match self.kind as u32 {
+        match self.kind {
             AST_NUMBER => {
                 write!(f, "Number({})", self.data as usize)
             }
+            AST_DEREF => {
+                write!(f, "Deref(expr: {})", self.data as usize)
+            }
+            AST_ADDRESS_OF => {
+                write!(f, "AddressOf(expr: {})", self.data as usize)
+            }
+            AST_ARG => {
+                let arg = unsafe { self.data.cast::<util::defs::AstArgument>().read() };
+                write!(
+                    f,
+                    "Arg(name: {:?}, arg_type: {})",
+                    unsafe {
+                        std::str::from_utf8(std::slice::from_raw_parts(arg.name, arg.name_len))
+                    },
+                    arg.arg_type,
+                )
+            }
+            AST_VAR_REF => {
+                let var_ref = unsafe { self.data.cast::<util::defs::AstVarRef>().read() };
+                if var_ref.resolved != 0 {
+                    write!(f, "VarRef({})", var_ref.resolved)
+                } else {
+                    write!(f, "VarRef(name: {:?})", unsafe {
+                        std::str::from_utf8(std::slice::from_raw_parts(
+                            var_ref.name,
+                            var_ref.name_len,
+                        ))
+                    },)
+                }
+            }
+            AST_VAR_DECL => {
+                let var_decl = unsafe { self.data.cast::<util::defs::AstVarDecl>().read() };
+                write!(
+                    f,
+                    "VarDecl(name: {:?}, var_type: {})",
+                    unsafe {
+                        std::str::from_utf8(std::slice::from_raw_parts(
+                            var_decl.name,
+                            var_decl.name_len,
+                        ))
+                    },
+                    var_decl.var_type,
+                )
+            }
+            AST_ASSIGNMENT => {
+                write!(
+                    f,
+                    "Assignment(dest: {}, src: {})",
+                    self.data as usize, self.extra
+                )
+            }
             AST_BINARY_OP => {
                 let BinaryExpr {
                     left,
@@ -77,10 +162,13 @@ impl std::fmt::Display for AstNode {
                 let func = unsafe { self.data.cast::<util::defs::AstFunction>().read() };
                 write!(
                     f,
-                    "Function(name: {:?}, return_type: {:?}, body: {})",
+                    "Function(name: {:?}, args: {:?}, return_type: {}, body: {})",
                     unsafe {
                         std::str::from_utf8(std::slice::from_raw_parts(func.name, func.name_len))
                     },
+                    unsafe {
+                        std::slice::from_raw_parts(func.args.cast::<u64>(), func.args_len as usize)
+                    },
                     func.return_type,
                     func.body
                 )
@@ -90,6 +178,12 @@ impl std::fmt::Display for AstNode {
                     std::slice::from_raw_parts(self.data.cast::<u64>(), self.extra as usize)
                 })
             }
+            AST_PLACE_TO_VALUE => {
+                write!(f, "PlaceToValue(place: {})", self.data as usize)
+            }
+            AST_VALUE_TO_PLACE => {
+                write!(f, "ValueToPlace(value: {})", self.data as usize)
+            }
             _ => write!(f, "UnknownNode"),
         }
     }
@@ -107,3 +201,54 @@ impl core::fmt::Display for Ast {
         writeln!(f, "\n]")
     }
 }
+
+impl core::fmt::Display for util::defs::SymEntry {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_struct("SymEntry")
+            .field_with("key", |f| {
+                f.debug_struct("Key")
+                    .field_with("kind", |f| {
+                        f.write_str(match self.key.kind {
+                            util::defs::SYM_KEY_SCOPE => "Scope",
+                            util::defs::SYM_KEY_SCOPE_NAME => "ScopeName",
+                            util::defs::SYM_KEY_PARENT_SCOPE => "ParentScope",
+                            util::defs::SYM_KEY_ARG => "Argument",
+                            util::defs::SYM_KEY_VAR => "Variable",
+                            _ => "Unknown",
+                        })
+                    })
+                    .field("scope", &self.key.scope_index)
+                    .field("span", &self.key.span)
+                    .field_with("ident", |f| {
+                        f.write_str(unsafe {
+                            &core::str::from_utf8_unchecked(core::slice::from_raw_parts(
+                                self.key.ident,
+                                self.key.ident_len,
+                            ))
+                        })
+                    })
+                    .finish()
+            })
+            .field_with("value", |f| {
+                let stct = &mut f.debug_struct("Value");
+                if self.extra == 0 {
+                    stct.field("ast_index", &self.index).finish()
+                } else if self.index != 0 {
+                    stct.field_with("ident", |f| {
+                        f.write_str(unsafe {
+                            core::str::from_utf8_unchecked(core::slice::from_raw_parts(
+                                self.index as *const u8,
+                                self.extra as usize,
+                            ))
+                        })
+                    })
+                    .finish()
+                } else {
+                    stct.field("index", &self.index)
+                        .field("extra", &self.extra)
+                        .finish()
+                }
+            })
+            .finish()
+    }
+}

lang/tests/shared/defs.rs

@@ -3,28 +3,49 @@
 
 unsafe extern "C" {
     pub unsafe fn parse_func(ast: *mut Ast) -> u64;
-    pub unsafe fn parse_args(ast: *mut Ast) -> (*const Argument, usize);
+    pub unsafe fn parse_args(ast: *mut Ast) -> (*const u64, usize);
     pub unsafe fn parse_primary_expr(ast: *mut Ast) -> (u64, bool);
     pub unsafe fn parse_binary_expr(ast: *mut Ast, precedence: u8) -> (u64, bool);
     pub unsafe fn parse_expr(ast: *mut Ast) -> u64;
     pub unsafe fn parse_statement(ast: *mut Ast) -> u64;
     pub unsafe fn parse_block(ast: *mut Ast) -> u64;
     pub unsafe fn parse_type(ast: *mut Ast) -> Type;
+    pub unsafe fn parse_prefix_expr(ast: *mut Ast) -> (u64, bool);
+    pub unsafe fn parse_assignment(ast: *mut Ast) -> (u64, bool);
+    pub unsafe fn ast_parse_let(ast: *mut Ast) -> (u64, bool);
+    pub unsafe fn symkey_cmp(a: *const SymKey, b: *const SymKey) -> i32;
+    pub unsafe fn ast_build_symtable(ast: *mut Ast, root_index: u64, symtable: *mut core::mem::MaybeUninit<SymbolTable>);
+    pub unsafe fn ast_walk_for_each(ast: *mut Ast, start_index: u64, ctx: *mut (), for_each: unsafe extern "C" fn(ctx: *mut (), *mut Ast, node_index: u64));
+    pub unsafe fn ast_resolve_var_refs(ast: *mut Ast);
 }
 
-pub const AST_FUNCTION: u32 = 1;
-pub const AST_BLOCK: u32 = 2;
-pub const AST_VARIABLE: u32 = 3;
-pub const AST_NUMBER: u32 = 4;
-pub const AST_BINARY_OP: u32 = 5;
-pub const AST_RETURN_STATEMENT: u32 = 6;
-pub const AST_VALUE_TO_PLACE: u32 = 7;
-pub const AST_PLACE_TO_VALUE: u32 = 8;
-pub const TYPE_VOID: u32 = 1;
-pub const TYPE_BOOL: u32 = 2;
-pub const TYPE_I32: u32 = 3;
-pub const TYPE_U32: u32 = 4;
-pub const TYPE_STR: u32 = 5;
+pub const AST_FUNCTION: u8 = 1;
+pub const AST_BLOCK: u8 = 2;
+pub const AST_VARIABLE: u8 = 3;
+pub const AST_NUMBER: u8 = 4;
+pub const AST_BINARY_OP: u8 = 5;
+pub const AST_RETURN_STATEMENT: u8 = 6;
+pub const AST_VALUE_TO_PLACE: u8 = 7;
+pub const AST_PLACE_TO_VALUE: u8 = 8;
+pub const AST_ASSIGNMENT: u8 = 9;
+pub const AST_DEREF: u8 = 10;
+pub const AST_ADDRESS_OF: u8 = 11;
+pub const AST_VAR_DECL: u8 = 12;
+pub const AST_VAR_REF: u8 = 13;
+pub const AST_ARG: u8 = 14;
+pub const TYPE_VOID: u8 = 1;
+pub const TYPE_BOOL: u8 = 2;
+pub const TYPE_I32: u8 = 3;
+pub const TYPE_U32: u8 = 4;
+pub const TYPE_STR: u8 = 5;
+pub const TYPE_POINTER: u8 = 6;
+pub const SYM_KEY_SCOPE: u8 = 1;
+pub const SYM_KEY_SCOPE_NAME: u8 = 2;
+pub const SYM_KEY_PARENT_SCOPE: u8 = 3;
+pub const SYM_KEY_START_LOCALS: u8 = 4;
+pub const SYM_KEY_ARG: u8 = 5;
+pub const SYM_KEY_VAR: u8 = 6;
+pub const SYM_KEY_END_LOCALS: u8 = 7;
 pub const TOKEN_EOF: u8 = 0;
 pub const TOKEN_LET: u8 = 1;
 pub const TOKEN_IF: u8 = 2;
@@ -58,10 +79,20 @@ pub const TOKEN_RBRACKET: u8 = 29;
 pub const TOKEN_VOID: u8 = 30;
 pub const TOKEN_SLASH: u8 = 31;
 pub const TOKEN_STAR: u8 = 32;
-pub const TOKEN_IDENT: u8 = 33;
-pub const TOKEN_NUMBER: u8 = 34;
-pub const TOKEN_STRING: u8 = 35;
-pub const TOKEN_COMMENT: u8 = 36;
+pub const TOKEN_U8: u8 = 33;
+pub const TOKEN_I8: u8 = 34;
+pub const TOKEN_U16: u8 = 35;
+pub const TOKEN_I16: u8 = 36;
+pub const TOKEN_U64: u8 = 37;
+pub const TOKEN_I64: u8 = 38;
+pub const TOKEN_USIZE: u8 = 39;
+pub const TOKEN_ISIZE: u8 = 40;
+pub const TOKEN_F32: u8 = 41;
+pub const TOKEN_F64: u8 = 42;
+pub const TOKEN_IDENT: u8 = 43;
+pub const TOKEN_NUMBER: u8 = 44;
+pub const TOKEN_STRING: u8 = 45;
+pub const TOKEN_COMMENT: u8 = 46;
 
 #[repr(C)]
 #[derive(Debug)]
@@ -79,7 +110,7 @@ pub struct AstNode {
 
 #[repr(C)]
 #[derive(Debug)]
-pub struct Argument {
+pub struct AstArgument {
     pub name: *const u8,
     pub name_len: usize,
     pub arg_type: Type,
@@ -89,6 +120,7 @@ pub struct Argument {
 #[derive(Debug)]
 pub struct Type {
     pub kind: u8,
+    pub data: u64,
 }
 
 #[repr(C)]
@@ -96,12 +128,20 @@ pub struct Type {
 pub struct AstFunction {
     pub name: *const u8,
     pub name_len: usize,
-    pub args: *const Argument,
+    pub args: *const u64,
     pub args_len: usize,
     pub return_type: Type,
     pub body: u64,
 }
 
+#[repr(C)]
+#[derive(Debug)]
+pub struct AstVarRef {
+    pub resolved: u64,
+    pub name: *const u8,
+    pub name_len: usize,
+}
+
 #[repr(C)]
 #[derive(Debug)]
 pub struct BinaryExpr {
@@ -110,4 +150,43 @@ pub struct BinaryExpr {
     pub right: u64,
 }
 
+#[repr(C)]
+#[derive(Debug)]
+pub struct AstVarDecl {
+    pub name: *const u8,
+    pub name_len: usize,
+    pub var_type: Type,
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct AstAssignment {
+    pub variable: u64,
+    pub expr: u64,
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct SymbolTable {
+    pub symtable: Vec<SymEntry>,
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct SymKey {
+    pub kind: u8,
+    pub scope_index: u64,
+    pub span: u64,
+    pub ident: *const u8,
+    pub ident_len: usize,
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct SymEntry {
+    pub key: SymKey,
+    pub index: u64,
+    pub extra: u64,
+}
+
 use super::vec::Vec;

lang/tests/shared/shared.rs

@@ -253,7 +253,11 @@ pub mod vec {
                     cmp_trampoline::<T, F>,
                     &raw mut cmp as *mut F as *mut (),
                 );
-                if vacant { Err(index) } else { Ok(index) }
+                if vacant {
+                    Err(index)
+                } else {
+                    Ok(index)
+                }
             }
         }
 
@@ -349,3 +353,52 @@ impl<'a, T: core::fmt::Display> core::fmt::Display for DisplaySlice<'a, T> {
         write!(f, "]")
     }
 }
+
+impl core::fmt::Display for defs::Type {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self.kind {
+            defs::TYPE_VOID => {
+                write!(f, "void")
+            }
+            defs::TYPE_BOOL => {
+                write!(f, "bool")
+            }
+            defs::TYPE_I32 => {
+                write!(f, "i32")
+            }
+            defs::TYPE_U32 => {
+                write!(f, "u32")
+            }
+            defs::TYPE_STR => {
+                write!(f, "str")
+            }
+            defs::TYPE_POINTER => {
+                let pointee = unsafe { (self.data as *const defs::Type).read() };
+                write!(f, "*{pointee}",)
+            }
+            _ => {
+                write!(f, "UnknownType")
+            }
+        }
+    }
+}
+
+#[repr(transparent)]
+pub struct Displayed<T: core::fmt::Display>(pub T);
+impl<T: core::fmt::Display> core::fmt::Debug for Displayed<T> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+pub trait DisplayedSliceExt {
+    type Displayed: core::fmt::Debug;
+    fn displayed(self) -> Self::Displayed;
+}
+
+impl<'a, T: core::fmt::Display> DisplayedSliceExt for &'a [T] {
+    type Displayed = &'a [Displayed<T>];
+    fn displayed(self) -> Self::Displayed {
+        unsafe { core::mem::transmute(self) }
+    }
+}

lang/tests/vec.rs

@@ -1,7 +1,7 @@
 #[path = "shared/shared.rs"]
 mod util;
 
-use util::{BlobVec, ffi::*, vec::Vec};
+use util::{ffi::*, vec::Vec, BlobVec};
 
 fn main() {
     static mut DROPS: usize = 1;
@@ -104,4 +104,8 @@ fn main() {
 
     _ = vec.insert_sorted(35, cmp);
     assert_eq!(vec.as_slice(), &[20, 30, 35, 40, 50]);
+
+    let mut vec = Vec::<u32>::new_with(100);
+    vec.insert_sorted(50, cmp);
+    assert_eq!(vec.as_slice(), &[50]);
 }