Revert "Auto merge of rust-lang#92816 - tmiasko:rm-llvm-asm, r=Amanieu"

This reverts commit a34c079, reversing
changes made to 128417f.

Author: drmorr0

compiler/rustc_ast/src/ast.rs

@@ -1267,7 +1267,7 @@ impl Expr {
             ExprKind::Break(..) => ExprPrecedence::Break,
             ExprKind::Continue(..) => ExprPrecedence::Continue,
             ExprKind::Ret(..) => ExprPrecedence::Ret,
-            ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
+            ExprKind::InlineAsm(..) | ExprKind::LlvmInlineAsm(..) => ExprPrecedence::InlineAsm,
             ExprKind::MacCall(..) => ExprPrecedence::Mac,
             ExprKind::Struct(..) => ExprPrecedence::Struct,
             ExprKind::Repeat(..) => ExprPrecedence::Repeat,
@@ -1437,6 +1437,8 @@ pub enum ExprKind {
 
     /// Output of the `asm!()` macro.
     InlineAsm(P<InlineAsm>),
+    /// Output of the `llvm_asm!()` macro.
+    LlvmInlineAsm(P<LlvmInlineAsm>),
 
     /// A macro invocation; pre-expansion.
     MacCall(MacCall),
@@ -2107,6 +2109,41 @@ pub struct InlineAsm {
     pub line_spans: Vec<Span>,
 }
 
+/// Inline assembly dialect.
+///
+/// E.g., `"intel"` as in `llvm_asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
+#[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy, Hash, HashStable_Generic)]
+pub enum LlvmAsmDialect {
+    Att,
+    Intel,
+}
+
+/// LLVM-style inline assembly.
+///
+/// E.g., `"={eax}"(result)` as in `llvm_asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
+#[derive(Clone, Encodable, Decodable, Debug)]
+pub struct LlvmInlineAsmOutput {
+    pub constraint: Symbol,
+    pub expr: P<Expr>,
+    pub is_rw: bool,
+    pub is_indirect: bool,
+}
+
+/// LLVM-style inline assembly.
+///
+/// E.g., `llvm_asm!("NOP");`.
+#[derive(Clone, Encodable, Decodable, Debug)]
+pub struct LlvmInlineAsm {
+    pub asm: Symbol,
+    pub asm_str_style: StrStyle,
+    pub outputs: Vec<LlvmInlineAsmOutput>,
+    pub inputs: Vec<(Symbol, P<Expr>)>,
+    pub clobbers: Vec<Symbol>,
+    pub volatile: bool,
+    pub alignstack: bool,
+    pub dialect: LlvmAsmDialect,
+}
+
 /// A parameter in a function header.
 ///
 /// E.g., `bar: usize` as in `fn foo(bar: usize)`.

compiler/rustc_ast/src/mut_visit.rs

@@ -1373,6 +1373,23 @@ pub fn noop_visit_expr<T: MutVisitor>(
             visit_opt(expr, |expr| vis.visit_expr(expr));
         }
         ExprKind::InlineAsm(asm) => noop_visit_inline_asm(asm, vis),
+        ExprKind::LlvmInlineAsm(asm) => {
+            let LlvmInlineAsm {
+                asm: _,
+                asm_str_style: _,
+                outputs,
+                inputs,
+                clobbers: _,
+                volatile: _,
+                alignstack: _,
+                dialect: _,
+            } = asm.deref_mut();
+            for out in outputs {
+                let LlvmInlineAsmOutput { constraint: _, expr, is_rw: _, is_indirect: _ } = out;
+                vis.visit_expr(expr);
+            }
+            visit_vec(inputs, |(_c, expr)| vis.visit_expr(expr));
+        }
         ExprKind::MacCall(mac) => vis.visit_mac_call(mac),
         ExprKind::Struct(se) => {
             let StructExpr { qself, path, fields, rest } = se.deref_mut();

compiler/rustc_ast/src/visit.rs

@@ -862,6 +862,14 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
         ExprKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
         ExprKind::Paren(ref subexpression) => visitor.visit_expr(subexpression),
         ExprKind::InlineAsm(ref asm) => walk_inline_asm(visitor, asm),
+        ExprKind::LlvmInlineAsm(ref ia) => {
+            for &(_, ref input) in &ia.inputs {
+                visitor.visit_expr(input)
+            }
+            for output in &ia.outputs {
+                visitor.visit_expr(&output.expr)
+            }
+        }
         ExprKind::Yield(ref optional_expression) => {
             walk_list!(visitor, visit_expr, optional_expression);
         }

compiler/rustc_ast_lowering/src/expr.rs

@@ -225,6 +225,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 ExprKind::InlineAsm(ref asm) => {
                     hir::ExprKind::InlineAsm(self.lower_inline_asm(e.span, asm))
                 }
+                ExprKind::LlvmInlineAsm(ref asm) => self.lower_expr_llvm_asm(asm),
                 ExprKind::Struct(ref se) => {
                     let rest = match &se.rest {
                         StructRest::Base(e) => Some(self.lower_expr(e)),
@@ -1294,6 +1295,38 @@ impl<'hir> LoweringContext<'_, 'hir> {
         result
     }
 
+    fn lower_expr_llvm_asm(&mut self, asm: &LlvmInlineAsm) -> hir::ExprKind<'hir> {
+        let inner = hir::LlvmInlineAsmInner {
+            inputs: asm.inputs.iter().map(|&(c, _)| c).collect(),
+            outputs: asm
+                .outputs
+                .iter()
+                .map(|out| hir::LlvmInlineAsmOutput {
+                    constraint: out.constraint,
+                    is_rw: out.is_rw,
+                    is_indirect: out.is_indirect,
+                    span: self.lower_span(out.expr.span),
+                })
+                .collect(),
+            asm: asm.asm,
+            asm_str_style: asm.asm_str_style,
+            clobbers: asm.clobbers.clone(),
+            volatile: asm.volatile,
+            alignstack: asm.alignstack,
+            dialect: asm.dialect,
+        };
+        let hir_asm = hir::LlvmInlineAsm {
+            inner,
+            inputs_exprs: self.arena.alloc_from_iter(
+                asm.inputs.iter().map(|&(_, ref input)| self.lower_expr_mut(input)),
+            ),
+            outputs_exprs: self
+                .arena
+                .alloc_from_iter(asm.outputs.iter().map(|out| self.lower_expr_mut(&out.expr))),
+        };
+        hir::ExprKind::LlvmInlineAsm(self.arena.alloc(hir_asm))
+    }
+
     fn lower_expr_field(&mut self, f: &ExprField) -> hir::ExprField<'hir> {
         hir::ExprField {
             hir_id: self.next_id(),

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1022,6 +1022,15 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 ExprKind::Let(..) if let Some(elem) = forbidden_let_reason => {
                     this.ban_let_expr(expr, elem);
                 },
+                ExprKind::LlvmInlineAsm(..) if !this.session.target.allow_asm => {
+                    struct_span_err!(
+                        this.session,
+                        expr.span,
+                        E0472,
+                        "llvm_asm! is unsupported on this target"
+                    )
+                    .emit();
+                }
                 ExprKind::Match(scrutinee, arms) => {
                     this.visit_expr(scrutinee);
                     for arm in arms {

compiler/rustc_ast_pretty/src/pprust/state/expr.rs

@@ -495,6 +495,62 @@ impl<'a> State<'a> {
                 self.word("asm!");
                 self.print_inline_asm(a);
             }
+            ast::ExprKind::LlvmInlineAsm(ref a) => {
+                self.word("llvm_asm!");
+                self.popen();
+                self.print_symbol(a.asm, a.asm_str_style);
+                self.word_space(":");
+
+                self.commasep(Inconsistent, &a.outputs, |s, out| {
+                    let constraint = out.constraint.as_str();
+                    let mut ch = constraint.chars();
+                    match ch.next() {
+                        Some('=') if out.is_rw => {
+                            s.print_string(&format!("+{}", ch.as_str()), ast::StrStyle::Cooked)
+                        }
+                        _ => s.print_string(&constraint, ast::StrStyle::Cooked),
+                    }
+                    s.popen();
+                    s.print_expr(&out.expr);
+                    s.pclose();
+                });
+                self.space();
+                self.word_space(":");
+
+                self.commasep(Inconsistent, &a.inputs, |s, &(co, ref o)| {
+                    s.print_symbol(co, ast::StrStyle::Cooked);
+                    s.popen();
+                    s.print_expr(o);
+                    s.pclose();
+                });
+                self.space();
+                self.word_space(":");
+
+                self.commasep(Inconsistent, &a.clobbers, |s, &co| {
+                    s.print_symbol(co, ast::StrStyle::Cooked);
+                });
+
+                let mut options = vec![];
+                if a.volatile {
+                    options.push("volatile");
+                }
+                if a.alignstack {
+                    options.push("alignstack");
+                }
+                if a.dialect == ast::LlvmAsmDialect::Intel {
+                    options.push("intel");
+                }
+
+                if !options.is_empty() {
+                    self.space();
+                    self.word_space(":");
+                    self.commasep(Inconsistent, &options, |s, &co| {
+                        s.print_string(co, ast::StrStyle::Cooked);
+                    });
+                }
+
+                self.pclose();
+            }
             ast::ExprKind::MacCall(ref m) => self.print_mac(m),
             ast::ExprKind::Paren(ref e) => {
                 self.popen();

compiler/rustc_borrowck/src/dataflow.rs

@@ -8,6 +8,7 @@ use rustc_mir_dataflow::ResultsVisitable;
 use rustc_mir_dataflow::{self, fmt::DebugWithContext, CallReturnPlaces, GenKill};
 use rustc_mir_dataflow::{Analysis, Direction, Results};
 use std::fmt;
+use std::iter;
 
 use crate::{
     places_conflict, BorrowSet, PlaceConflictBias, PlaceExt, RegionInferenceContext, ToRegionVid,
@@ -384,6 +385,14 @@ impl<'tcx> rustc_mir_dataflow::GenKillAnalysis<'tcx> for Borrows<'_, 'tcx> {
                 self.kill_borrows_on_place(trans, Place::from(local));
             }
 
+            mir::StatementKind::LlvmInlineAsm(ref asm) => {
+                for (output, kind) in iter::zip(&*asm.outputs, &asm.asm.outputs) {
+                    if !kind.is_indirect && !kind.is_rw {
+                        self.kill_borrows_on_place(trans, *output);
+                    }
+                }
+            }
+
             mir::StatementKind::FakeRead(..)
             | mir::StatementKind::SetDiscriminant { .. }
             | mir::StatementKind::StorageLive(..)

compiler/rustc_borrowck/src/def_use.rs

@@ -16,6 +16,9 @@ pub fn categorize(context: PlaceContext) -> Option<DefUse> {
 
         PlaceContext::MutatingUse(MutatingUseContext::Store) |
 
+        // This is potentially both a def and a use...
+        PlaceContext::MutatingUse(MutatingUseContext::LlvmAsmOutput) |
+
         // We let Call define the result in both the success and
         // unwind cases. This is not really correct, however it
         // does not seem to be observable due to the way that we

compiler/rustc_borrowck/src/invalidation.rs

@@ -5,11 +5,12 @@ use rustc_middle::mir::{BorrowKind, Mutability, Operand};
 use rustc_middle::mir::{InlineAsmOperand, Terminator, TerminatorKind};
 use rustc_middle::mir::{Statement, StatementKind};
 use rustc_middle::ty::TyCtxt;
+use std::iter;
 
 use crate::{
     borrow_set::BorrowSet, facts::AllFacts, location::LocationTable, path_utils::*, AccessDepth,
-    Activation, ArtificialField, BorrowIndex, Deep, LocalMutationIsAllowed, Read, ReadKind,
-    ReadOrWrite, Reservation, Shallow, Write, WriteKind,
+    Activation, ArtificialField, BorrowIndex, Deep, JustWrite, LocalMutationIsAllowed, MutateMode,
+    Read, ReadKind, ReadOrWrite, Reservation, Shallow, Write, WriteAndRead, WriteKind,
 };
 
 pub(super) fn generate_invalidates<'tcx>(
@@ -58,13 +59,37 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
             StatementKind::Assign(box (lhs, rhs)) => {
                 self.consume_rvalue(location, rhs);
 
-                self.mutate_place(location, *lhs, Shallow(None));
+                self.mutate_place(location, *lhs, Shallow(None), JustWrite);
             }
             StatementKind::FakeRead(box (_, _)) => {
                 // Only relevant for initialized/liveness/safety checks.
             }
             StatementKind::SetDiscriminant { place, variant_index: _ } => {
-                self.mutate_place(location, **place, Shallow(None));
+                self.mutate_place(location, **place, Shallow(None), JustWrite);
+            }
+            StatementKind::LlvmInlineAsm(asm) => {
+                for (o, output) in iter::zip(&asm.asm.outputs, &*asm.outputs) {
+                    if o.is_indirect {
+                        // FIXME(eddyb) indirect inline asm outputs should
+                        // be encoded through MIR place derefs instead.
+                        self.access_place(
+                            location,
+                            *output,
+                            (Deep, Read(ReadKind::Copy)),
+                            LocalMutationIsAllowed::No,
+                        );
+                    } else {
+                        self.mutate_place(
+                            location,
+                            *output,
+                            if o.is_rw { Deep } else { Shallow(None) },
+                            if o.is_rw { WriteAndRead } else { JustWrite },
+                        );
+                    }
+                }
+                for (_, input) in asm.inputs.iter() {
+                    self.consume_operand(location, input);
+                }
             }
             StatementKind::CopyNonOverlapping(box rustc_middle::mir::CopyNonOverlapping {
                 ref src,
@@ -117,7 +142,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                 target: _,
                 unwind: _,
             } => {
-                self.mutate_place(location, *drop_place, Deep);
+                self.mutate_place(location, *drop_place, Deep, JustWrite);
                 self.consume_operand(location, new_value);
             }
             TerminatorKind::Call {
@@ -133,7 +158,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                     self.consume_operand(location, arg);
                 }
                 if let Some((dest, _ /*bb*/)) = destination {
-                    self.mutate_place(location, *dest, Deep);
+                    self.mutate_place(location, *dest, Deep, JustWrite);
                 }
             }
             TerminatorKind::Assert { ref cond, expected: _, ref msg, target: _, cleanup: _ } => {
@@ -156,7 +181,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                     }
                 }
 
-                self.mutate_place(location, *resume_arg, Deep);
+                self.mutate_place(location, *resume_arg, Deep, JustWrite);
             }
             TerminatorKind::Resume | TerminatorKind::Return | TerminatorKind::GeneratorDrop => {
                 // Invalidate all borrows of local places
@@ -183,13 +208,13 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                         }
                         InlineAsmOperand::Out { reg: _, late: _, place, .. } => {
                             if let Some(place) = place {
-                                self.mutate_place(location, place, Shallow(None));
+                                self.mutate_place(location, place, Shallow(None), JustWrite);
                             }
                         }
                         InlineAsmOperand::InOut { reg: _, late: _, ref in_value, out_place } => {
                             self.consume_operand(location, in_value);
                             if let Some(out_place) = out_place {
-                                self.mutate_place(location, out_place, Shallow(None));
+                                self.mutate_place(location, out_place, Shallow(None), JustWrite);
                             }
                         }
                         InlineAsmOperand::Const { value: _ }
@@ -213,7 +238,13 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
 
 impl<'cx, 'tcx> InvalidationGenerator<'cx, 'tcx> {
     /// Simulates mutation of a place.
-    fn mutate_place(&mut self, location: Location, place: Place<'tcx>, kind: AccessDepth) {
+    fn mutate_place(
+        &mut self,
+        location: Location,
+        place: Place<'tcx>,
+        kind: AccessDepth,
+        _mode: MutateMode,
+    ) {
         self.access_place(
             location,
             place,