Rollup merge of #41249 - GuillaumeGomez:rustdoc-render, r=steveklabnik,frewsxcv

[rust.git] / src / librustc_mir / transform / type_check.rs

diff --git a/src/librustc_mir/transform/type_check.rs b/src/librustc_mir/transform/type_check.rs
index f98bb73c504dcfb00e44a5247f184ee4b930e3f5..bfb08de56d8bb899b15509b8f4d849992851bd62 100644 (file)
--- a/src/librustc_mir/transform/type_check.rs
+++ b/src/librustc_mir/transform/type_check.rs
@@ -15,6 +15,7 @@
 use rustc::traits::{self, Reveal};
 use rustc::ty::fold::TypeFoldable;
 use rustc::ty::{self, Ty, TyCtxt, TypeVariants};
+use rustc::middle::const_val::ConstVal;
 use rustc::mir::*;
 use rustc::mir::tcx::LvalueTy;
 use rustc::mir::transform::{MirPass, MirSource, Pass};
@@ -23,6 +24,7 @@
 use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
 
+use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::indexed_vec::Idx;
 
 fn mirbug(tcx: TyCtxt, span: Span, msg: &str) {
@@ -86,6 +88,11 @@ fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) {
         self.sanitize_type(rvalue, rval_ty);
     }
 
+    fn visit_local_decl(&mut self, local_decl: &LocalDecl<'tcx>) {
+        self.super_local_decl(local_decl);
+        self.sanitize_type(local_decl, local_decl.ty);
+    }
+
     fn visit_mir(&mut self, mir: &Mir<'tcx>) {
         self.sanitize_type(&"return type", mir.return_ty);
         for local_decl in &mir.local_decls {
@@ -316,6 +323,7 @@ pub struct TypeChecker<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     fulfillment_cx: traits::FulfillmentContext<'tcx>,
     last_span: Span,
     body_id: ast::NodeId,
+    reported_errors: FxHashSet<(Ty<'tcx>, Span)>,
 }
 
 impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
@@ -325,6 +333,7 @@ fn new(infcx: &'a InferCtxt<'a, 'gcx, 'tcx>, body_id: ast::NodeId) -> Self {
             fulfillment_cx: traits::FulfillmentContext::new(),
             last_span: DUMMY_SP,
             body_id: body_id,
+            reported_errors: FxHashSet(),
         }
     }
 
@@ -526,7 +535,9 @@ fn check_call_inputs(&mut self,
     fn is_box_free(&self, operand: &Operand<'tcx>) -> bool {
         match operand {
             &Operand::Constant(Constant {
-                literal: Literal::Item { def_id, .. }, ..
+                literal: Literal::Value {
+                    value: ConstVal::Function(def_id, _), ..
+                }, ..
             }) => {
                 Some(def_id) == self.tcx().lang_items.box_free_fn()
             }
@@ -638,9 +649,43 @@ fn assert_iscleanup(&mut self,
         }
     }
 
-    fn typeck_mir(&mut self, mir: &Mir<'tcx>) {
+    fn check_local(&mut self, mir: &Mir<'gcx>, local: Local, local_decl: &LocalDecl<'gcx>) {
+        match mir.local_kind(local) {
+            LocalKind::ReturnPointer | LocalKind::Arg => {
+                // return values of normal functions are required to be
+                // sized by typeck, but return values of ADT constructors are
+                // not because we don't include a `Self: Sized` bounds on them.
+                //
+                // Unbound parts of arguments were never required to be Sized
+                // - maybe we should make that a warning.
+                return
+            }
+            LocalKind::Var | LocalKind::Temp => {}
+        }
+
+        let span = local_decl.source_info.span;
+        let ty = local_decl.ty;
+        if !ty.is_sized(self.tcx().global_tcx(), self.infcx.param_env(), span) {
+            // in current MIR construction, all non-control-flow rvalue
+            // expressions evaluate through `as_temp` or `into` a return
+            // slot or local, so to find all unsized rvalues it is enough
+            // to check all temps, return slots and locals.
+            if let None = self.reported_errors.replace((ty, span)) {
+                span_err!(self.tcx().sess, span, E0161,
+                          "cannot move a value of type {0}: the size of {0} \
+                           cannot be statically determined", ty);
+            }
+        }
+    }
+
+    fn typeck_mir(&mut self, mir: &Mir<'gcx>) {
         self.last_span = mir.span;
         debug!("run_on_mir: {:?}", mir.span);
+
+        for (local, local_decl) in mir.local_decls.iter_enumerated() {
+            self.check_local(mir, local, local_decl);
+        }
+
         for block in mir.basic_blocks() {
             for stmt in &block.statements {
                 if stmt.source_info.span != DUMMY_SP {
@@ -695,16 +740,18 @@ pub fn new() -> Self {
 impl<'tcx> MirPass<'tcx> for TypeckMir {
     fn run_pass<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
                     src: MirSource, mir: &mut Mir<'tcx>) {
-        debug!("run_pass: {}", tcx.node_path_str(src.item_id()));
+        let item_id = src.item_id();
+        let def_id = tcx.hir.local_def_id(item_id);
+        debug!("run_pass: {}", tcx.item_path_str(def_id));
 
         if tcx.sess.err_count() > 0 {
             // compiling a broken program can obviously result in a
             // broken MIR, so try not to report duplicate errors.
             return;
         }
-        let param_env = ty::ParameterEnvironment::for_item(tcx, src.item_id());
+        let param_env = ty::ParameterEnvironment::for_item(tcx, item_id);
         tcx.infer_ctxt(param_env, Reveal::UserFacing).enter(|infcx| {
-            let mut checker = TypeChecker::new(&infcx, src.item_id());
+            let mut checker = TypeChecker::new(&infcx, item_id);
             {
                 let mut verifier = TypeVerifier::new(&mut checker, mir);
                 verifier.visit_mir(mir);