Lower asm expressions

src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs

@@ -1,6 +1,8 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
 
+mod asm;
+
 use std::mem;
 
 use base_db::CrateId;
@@ -35,8 +37,8 @@ use crate::{
             FormatPlaceholder, FormatSign, FormatTrait,
         },
         Array, Binding, BindingAnnotation, BindingId, BindingProblems, CaptureBy, ClosureKind,
-        Expr, ExprId, InlineAsm, Label, LabelId, Literal, LiteralOrConst, MatchArm, Movability,
-        OffsetOf, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
+        Expr, ExprId, Label, LabelId, Literal, LiteralOrConst, MatchArm, Movability, OffsetOf, Pat,
+        PatId, RecordFieldPat, RecordLitField, Statement,
     },
     item_scope::BuiltinShadowMode,
     lang_item::LangItem,
@@ -693,13 +695,7 @@ impl ExprCollector<'_> {
                 }
             }
             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
-            ast::Expr::AsmExpr(e) => {
-                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::AsmExpr(e) => self.lower_inline_asm(e, syntax_ptr),
             ast::Expr::OffsetOfExpr(e) => {
                 let container = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
                 let fields = e.fields().map(|it| it.as_name()).collect();
@@ -2064,6 +2060,7 @@ impl ExprCollector<'_> {
             is_assignee_expr: false,
         })
     }
+
     // endregion: format
 
     fn lang_path(&self, lang: LangItem) -> Option<Path> {

src/tools/rust-analyzer/crates/hir-def/src/body/lower/asm.rs

@@ -0,0 +1,230 @@
+use hir_expand::name::Name;
+use intern::Symbol;
+use rustc_hash::{FxHashMap, FxHashSet};
+use syntax::{
+    ast::{self, HasName, IsString},
+    AstNode, AstPtr, AstToken, T,
+};
+use tt::{TextRange, TextSize};
+
+use crate::{
+    body::lower::{ExprCollector, FxIndexSet},
+    hir::{AsmOperand, AsmOptions, Expr, ExprId, InlineAsm, InlineAsmRegOrRegClass},
+};
+
+impl ExprCollector<'_> {
+    pub(super) fn lower_inline_asm(
+        &mut self,
+        asm: ast::AsmExpr,
+        syntax_ptr: AstPtr<ast::Expr>,
+    ) -> ExprId {
+        let mut clobber_abis = FxIndexSet::default();
+        let mut operands = vec![];
+        let mut options = AsmOptions::empty();
+
+        let mut named_pos: FxHashMap<usize, Symbol> = Default::default();
+        let mut named_args: FxHashMap<Symbol, usize> = Default::default();
+        let mut reg_args: FxHashSet<usize> = Default::default();
+        for operand in asm.asm_operands() {
+            let slot = operands.len();
+            let mut lower_reg = |reg: Option<ast::AsmRegSpec>| {
+                let reg = reg?;
+                if let Some(string) = reg.string_token() {
+                    reg_args.insert(slot);
+                    Some(InlineAsmRegOrRegClass::Reg(Symbol::intern(string.text())))
+                } else {
+                    reg.name_ref().map(|name_ref| {
+                        InlineAsmRegOrRegClass::RegClass(Symbol::intern(&name_ref.text()))
+                    })
+                }
+            };
+
+            let op = match operand {
+                ast::AsmOperand::AsmClobberAbi(clobber_abi) => {
+                    if let Some(abi_name) = clobber_abi.string_token() {
+                        clobber_abis.insert(Symbol::intern(abi_name.text()));
+                    }
+                    continue;
+                }
+                ast::AsmOperand::AsmOptions(opt) => {
+                    opt.asm_options().for_each(|opt| {
+                        options |= match opt.syntax().first_token().map_or(T![$], |it| it.kind()) {
+                            T![att_syntax] => AsmOptions::ATT_SYNTAX,
+                            T![may_unwind] => AsmOptions::MAY_UNWIND,
+                            T![nomem] => AsmOptions::NOMEM,
+                            T![noreturn] => AsmOptions::NORETURN,
+                            T![nostack] => AsmOptions::NOSTACK,
+                            T![preserves_flags] => AsmOptions::PRESERVES_FLAGS,
+                            T![pure] => AsmOptions::PURE,
+                            T![raw] => AsmOptions::RAW,
+                            T![readonly] => AsmOptions::READONLY,
+                            _ => return,
+                        }
+                    });
+                    continue;
+                }
+                ast::AsmOperand::AsmRegOperand(op) => {
+                    let Some(dir_spec) = op.asm_dir_spec() else {
+                        continue;
+                    };
+                    let Some(reg) = lower_reg(op.asm_reg_spec()) else {
+                        continue;
+                    };
+                    if let Some(name) = op.name() {
+                        let sym = Symbol::intern(&name.text());
+                        named_args.insert(sym.clone(), slot);
+                        named_pos.insert(slot, sym);
+                    }
+                    if dir_spec.in_token().is_some() {
+                        let expr = self
+                            .collect_expr_opt(op.asm_operand_expr().and_then(|it| it.in_expr()));
+                        AsmOperand::In { reg, expr }
+                    } else if dir_spec.out_token().is_some() {
+                        let expr = self
+                            .collect_expr_opt(op.asm_operand_expr().and_then(|it| it.in_expr()));
+                        AsmOperand::Out { reg, expr: Some(expr), late: false }
+                    } else if dir_spec.lateout_token().is_some() {
+                        let expr = self
+                            .collect_expr_opt(op.asm_operand_expr().and_then(|it| it.in_expr()));
+                        AsmOperand::Out { reg, expr: Some(expr), late: true }
+                    } else if dir_spec.inout_token().is_some() {
+                        let Some(op_expr) = op.asm_operand_expr() else { continue };
+                        let in_expr = self.collect_expr_opt(op_expr.in_expr());
+                        let out_expr = op_expr.out_expr().map(|it| self.collect_expr(it));
+                        match out_expr {
+                            Some(out_expr) => AsmOperand::SplitInOut {
+                                reg,
+                                in_expr,
+                                out_expr: Some(out_expr),
+                                late: false,
+                            },
+                            None => AsmOperand::InOut { reg, expr: in_expr, late: false },
+                        }
+                    } else if dir_spec.inlateout_token().is_some() {
+                        let Some(op_expr) = op.asm_operand_expr() else { continue };
+                        let in_expr = self.collect_expr_opt(op_expr.in_expr());
+                        let out_expr = op_expr.out_expr().map(|it| self.collect_expr(it));
+                        match out_expr {
+                            Some(out_expr) => AsmOperand::SplitInOut {
+                                reg,
+                                in_expr,
+                                out_expr: Some(out_expr),
+                                late: false,
+                            },
+                            None => AsmOperand::InOut { reg, expr: in_expr, late: false },
+                        }
+                    } else {
+                        continue;
+                    }
+                }
+                ast::AsmOperand::AsmLabel(l) => {
+                    AsmOperand::Label(self.collect_block_opt(l.block_expr()))
+                }
+                ast::AsmOperand::AsmConst(c) => AsmOperand::Const(self.collect_expr_opt(c.expr())),
+                ast::AsmOperand::AsmSym(s) => {
+                    let Some(path) = s.path().and_then(|p| self.expander.parse_path(self.db, p))
+                    else {
+                        continue;
+                    };
+                    AsmOperand::Sym(path)
+                }
+            };
+            operands.push(op);
+        }
+
+        let mut mappings = vec![];
+        let mut curarg = 0;
+        if !options.contains(AsmOptions::RAW) {
+            // Don't treat raw asm as a format string.
+            asm.template()
+                .filter_map(|it| Some((it.clone(), self.expand_macros_to_string(it)?)))
+                .for_each(|(expr, (s, is_direct_literal))| {
+                    let Ok(text) = s.value() else {
+                        return;
+                    };
+                    let template_snippet = match expr {
+                        ast::Expr::Literal(literal) => match literal.kind() {
+                            ast::LiteralKind::String(s) => Some(s.text().to_owned()),
+                            _ => None,
+                        },
+                        _ => None,
+                    };
+                    let str_style = match s.quote_offsets() {
+                        Some(offsets) => {
+                            let raw = usize::from(offsets.quotes.0.len()) - 1;
+                            // subtract 1 for the `r` prefix
+                            (raw != 0).then(|| raw - 1)
+                        }
+                        None => None,
+                    };
+
+                    let mut parser = rustc_parse_format::Parser::new(
+                        &text,
+                        str_style,
+                        template_snippet,
+                        false,
+                        rustc_parse_format::ParseMode::InlineAsm,
+                    );
+                    parser.curarg = curarg;
+
+                    let mut unverified_pieces = Vec::new();
+                    while let Some(piece) = parser.next() {
+                        if !parser.errors.is_empty() {
+                            break;
+                        } else {
+                            unverified_pieces.push(piece);
+                        }
+                    }
+
+                    curarg = parser.curarg;
+
+                    let to_span = |inner_span: rustc_parse_format::InnerSpan| {
+                        is_direct_literal.then(|| {
+                            TextRange::new(
+                                inner_span.start.try_into().unwrap(),
+                                inner_span.end.try_into().unwrap(),
+                            ) - TextSize::from(str_style.map(|it| it + 1).unwrap_or(0) as u32 + 1)
+                        })
+                    };
+                    for piece in unverified_pieces {
+                        match piece {
+                            rustc_parse_format::Piece::String(_) => {}
+                            rustc_parse_format::Piece::NextArgument(arg) => {
+                                // let span = arg_spans.next();
+
+                                let _operand_idx = match arg.position {
+                                    rustc_parse_format::ArgumentIs(idx)
+                                    | rustc_parse_format::ArgumentImplicitlyIs(idx) => {
+                                        if idx >= operands.len()
+                                            || named_pos.contains_key(&idx)
+                                            || reg_args.contains(&idx)
+                                        {
+                                            None
+                                        } else {
+                                            Some(idx)
+                                        }
+                                    }
+                                    rustc_parse_format::ArgumentNamed(name) => {
+                                        let name = Symbol::intern(name);
+                                        if let Some(position_span) = to_span(arg.position_span) {
+                                            mappings.push((
+                                                position_span,
+                                                Name::new_symbol_root(name.clone()),
+                                            ));
+                                        }
+                                        named_args.get(&name).copied()
+                                    }
+                                };
+                            }
+                        }
+                    }
+                })
+        };
+        let idx = self.alloc_expr(
+            Expr::InlineAsm(InlineAsm { operands: operands.into_boxed_slice(), options }),
+            syntax_ptr,
+        );
+        self.source_map.format_args_template_map.insert(idx, mappings);
+        idx
+    }
+}