Parse builtin#asm expressions

.typos.toml

@@ -15,6 +15,7 @@ extend-ignore-re = [
     '"flate2"',
     "raison d'être",
     "inout",
+    "INOUT",
     "optin"
 ]
 

Cargo.toml

@@ -185,6 +185,7 @@ style = { level = "warn", priority = -1 }
 suspicious = { level = "warn", priority = -1 }
 
 ## allow following lints
+too_long_first_doc_paragraph = "allow"
 # subjective
 single_match = "allow"
 # () makes a fine error in most cases

crates/hir-def/src/body/lower.rs

@@ -694,8 +694,11 @@ impl ExprCollector<'_> {
             }
             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
             ast::Expr::AsmExpr(e) => {
-                let e = self.collect_expr_opt(e.expr());
-                self.alloc_expr(Expr::InlineAsm(InlineAsm { e }), syntax_ptr)
+                let template = e.template().map(|it| self.collect_expr(it)).collect();
+                self.alloc_expr(
+                    Expr::InlineAsm(InlineAsm { template, operands: Box::default() }),
+                    syntax_ptr,
+                )
             }
             ast::Expr::OffsetOfExpr(e) => {
                 let container = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));

crates/hir-def/src/hir.rs

@@ -307,7 +307,8 @@ pub struct OffsetOf {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct InlineAsm {
-    pub e: ExprId,
+    pub template: Box<[ExprId]>,
+    pub operands: Box<[()]>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -372,7 +373,7 @@ impl Expr {
         match self {
             Expr::Missing => {}
             Expr::Path(_) | Expr::OffsetOf(_) => {}
-            Expr::InlineAsm(it) => f(it.e),
+            Expr::InlineAsm(it) => it.template.iter().copied().for_each(f),
             Expr::If { condition, then_branch, else_branch } => {
                 f(*condition);
                 f(*then_branch);

crates/hir-ty/src/infer/closure.rs

@@ -666,7 +666,9 @@ impl InferenceContext<'_> {
     fn walk_expr_without_adjust(&mut self, tgt_expr: ExprId) {
         match &self.body[tgt_expr] {
             Expr::OffsetOf(_) => (),
-            Expr::InlineAsm(e) => self.walk_expr_without_adjust(e.e),
+            Expr::InlineAsm(e) => {
+                e.template.iter().for_each(|it| self.walk_expr_without_adjust(*it))
+            }
             Expr::If { condition, then_branch, else_branch } => {
                 self.consume_expr(*condition);
                 self.consume_expr(*then_branch);

crates/hir-ty/src/infer/expr.rs

@@ -925,7 +925,7 @@ impl InferenceContext<'_> {
             }
             Expr::OffsetOf(_) => TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(Interner),
             Expr::InlineAsm(it) => {
-                self.infer_expr_no_expect(it.e);
+                it.template.iter().for_each(|&expr| _ = self.infer_expr_no_expect(expr));
                 self.result.standard_types.unit.clone()
             }
         };

crates/hir-ty/src/infer/mutability.rs

@@ -39,7 +39,10 @@ impl InferenceContext<'_> {
     fn infer_mut_expr_without_adjust(&mut self, tgt_expr: ExprId, mutability: Mutability) {
         match &self.body[tgt_expr] {
             Expr::Missing => (),
-            Expr::InlineAsm(e) => self.infer_mut_expr_without_adjust(e.e, Mutability::Not),
+            Expr::InlineAsm(e) => e
+                .template
+                .iter()
+                .for_each(|&expr| self.infer_mut_expr_without_adjust(expr, Mutability::Not)),
             Expr::OffsetOf(_) => (),
             &Expr::If { condition, then_branch, else_branch } => {
                 self.infer_mut_expr(condition, Mutability::Not);
@@ -129,7 +132,7 @@ impl InferenceContext<'_> {
                                     target,
                                 }) = base_adjustments
                                 {
-                                    // For assignee exprs `IndexMut` obiligations are already applied
+                                    // For assignee exprs `IndexMut` obligations are already applied
                                     if !is_assignee_expr {
                                         if let TyKind::Ref(_, _, ty) = target.kind(Interner) {
                                             base_ty = Some(ty.clone());

crates/parser/src/grammar/expressions/atom.rs

@@ -245,7 +245,7 @@ fn tuple_expr(p: &mut Parser<'_>) -> CompletedMarker {
 
 // test builtin_expr
 // fn foo() {
-//     builtin#asm(0);
+//     builtin#asm("");
 //     builtin#format_args("", 0, 1, a = 2 + 3, a + b);
 //     builtin#offset_of(Foo, bar.baz.0);
 // }
@@ -297,18 +297,175 @@ fn builtin_expr(p: &mut Parser<'_>) -> Option<CompletedMarker> {
         p.expect(T![')']);
         Some(m.complete(p, FORMAT_ARGS_EXPR))
     } else if p.at_contextual_kw(T![asm]) {
-        p.bump_remap(T![asm]);
-        p.expect(T!['(']);
-        // FIXME: We just put expression here so highlighting kind of keeps working
-        expr(p);
-        p.expect(T![')']);
-        Some(m.complete(p, ASM_EXPR))
+        parse_asm_expr(p, m)
     } else {
         m.abandon(p);
         None
     }
 }
 
+// test asm_expr
+// fn foo() {
+//     builtin#asm(
+//         "mov {tmp}, {x}",
+//         "shl {tmp}, 1",
+//         "shl {x}, 2",
+//         "add {x}, {tmp}",
+//         x = inout(reg) x,
+//         tmp = out(reg) _,
+//     );
+// }
+fn parse_asm_expr(p: &mut Parser<'_>, m: Marker) -> Option<CompletedMarker> {
+    p.bump_remap(T![asm]);
+    p.expect(T!['(']);
+    if expr(p).is_none() {
+        p.err_and_bump("expected asm template");
+    }
+    let mut allow_templates = true;
+    while !p.at(EOF) && !p.at(T![')']) {
+        p.expect(T![,]);
+        // accept trailing commas
+        if p.at(T![')']) {
+            break;
+        }
+
+        // Parse clobber_abi
+        if p.eat_contextual_kw(T![clobber_abi]) {
+            parse_clobber_abi(p);
+            allow_templates = false;
+            continue;
+        }
+
+        // Parse options
+        if p.eat_contextual_kw(T![options]) {
+            parse_options(p);
+            allow_templates = false;
+            continue;
+        }
+
+        // Parse operand names
+        if p.at(T![ident]) && p.nth_at(1, T![=]) {
+            name(p);
+            p.bump(T![=]);
+            allow_templates = false;
+            true
+        } else {
+            false
+        };
+
+        let op = p.start();
+        if p.eat(T![in]) {
+            parse_reg(p);
+            expr(p);
+            op.complete(p, ASM_REG_OPERAND);
+        } else if p.eat_contextual_kw(T![out]) {
+            parse_reg(p);
+            expr(p);
+            op.complete(p, ASM_REG_OPERAND);
+        } else if p.eat_contextual_kw(T![lateout]) {
+            parse_reg(p);
+            expr(p);
+            op.complete(p, ASM_REG_OPERAND);
+        } else if p.eat_contextual_kw(T![inout]) {
+            parse_reg(p);
+            expr(p);
+            if p.eat(T![=>]) {
+                expr(p);
+            }
+            op.complete(p, ASM_REG_OPERAND);
+        } else if p.eat_contextual_kw(T![inlateout]) {
+            parse_reg(p);
+            expr(p);
+            if p.eat(T![=>]) {
+                expr(p);
+            }
+            op.complete(p, ASM_REG_OPERAND);
+        } else if p.eat_contextual_kw(T![label]) {
+            block_expr(p);
+            op.complete(p, ASM_LABEL);
+        } else if p.eat(T![const]) {
+            expr(p);
+            op.complete(p, ASM_CONST);
+        } else if p.eat_contextual_kw(T![sym]) {
+            expr(p);
+            op.complete(p, ASM_SYM);
+        } else if allow_templates {
+            op.abandon(p);
+            if expr(p).is_none() {
+                p.err_and_bump("expected asm template");
+            }
+            continue;
+        } else {
+            op.abandon(p);
+            p.err_and_bump("expected asm operand");
+            if p.at(T!['}']) {
+                break;
+            }
+            continue;
+        };
+        allow_templates = false;
+    }
+    p.expect(T![')']);
+    Some(m.complete(p, ASM_EXPR))
+}
+
+fn parse_options(p: &mut Parser<'_>) {
+    p.expect(T!['(']);
+
+    while !p.eat(T![')']) && !p.at(EOF) {
+        const OPTIONS: &[SyntaxKind] = &[
+            T![pure],
+            T![nomem],
+            T![readonly],
+            T![preserves_flags],
+            T![noreturn],
+            T![nostack],
+            T![may_unwind],
+            T![att_syntax],
+            T![raw],
+        ];
+
+        if !OPTIONS.iter().any(|&syntax| p.eat(syntax)) {
+            p.err_and_bump("expected asm option");
+            continue;
+        }
+
+        // Allow trailing commas
+        if p.eat(T![')']) {
+            break;
+        }
+        p.expect(T![,]);
+    }
+}
+
+fn parse_clobber_abi(p: &mut Parser<'_>) {
+    p.expect(T!['(']);
+
+    while !p.eat(T![')']) && !p.at(EOF) {
+        if !p.expect(T![string]) {
+            break;
+        }
+
+        // Allow trailing commas
+        if p.eat(T![')']) {
+            break;
+        }
+        p.expect(T![,]);
+    }
+}
+
+fn parse_reg(p: &mut Parser<'_>) {
+    p.expect(T!['(']);
+    if p.at(T![ident]) {
+        name_ref(p)
+    } else if p.at(T![string]) {
+        p.bump_any()
+    } else {
+        p.err_and_bump("expected register name");
+    }
+    p.expect(T![')']);
+}
+
 // test array_expr
 // fn foo() {
 //     [];

crates/parser/src/parser.rs

@@ -131,6 +131,14 @@ impl<'t> Parser<'t> {
         true
     }
 
+    pub(crate) fn eat_contextual_kw(&mut self, kind: SyntaxKind) -> bool {
+        if !self.at_contextual_kw(kind) {
+            return false;
+        }
+        self.bump_remap(kind);
+        true
+    }
+
     fn at_composite2(&self, n: usize, k1: SyntaxKind, k2: SyntaxKind) -> bool {
         self.inp.kind(self.pos + n) == k1
             && self.inp.kind(self.pos + n + 1) == k2