Merge from rustc

8 files changed, 37 insertions, 48 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 72648e5ade4..87b6f0e914c 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -87,7 +87,7 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<S
 
             // Only consider nodes that actually have exported symbols.
             match tcx.def_kind(def_id) {
-                DefKind::Fn | DefKind::Static(_) => {}
+                DefKind::Fn | DefKind::Static { .. } => {}
                 DefKind::AssocFn if tcx.impl_of_method(def_id.to_def_id()).is_some() => {}
                 _ => return None,
             };
@@ -483,7 +483,7 @@ fn symbol_export_level(tcx: TyCtxt<'_>, sym_def_id: DefId) -> SymbolExportLevel
         let target = &tcx.sess.target.llvm_target;
         // WebAssembly cannot export data symbols, so reduce their export level
         if target.contains("emscripten") {
-            if let DefKind::Static(_) = tcx.def_kind(sym_def_id) {
+            if let DefKind::Static { .. } = tcx.def_kind(sym_def_id) {
                 return SymbolExportLevel::Rust;
             }
         }
diff --git a/compiler/rustc_codegen_ssa/src/common.rs b/compiler/rustc_codegen_ssa/src/common.rs
index 641ac3eb808..44a2434238d 100644
--- a/compiler/rustc_codegen_ssa/src/common.rs
+++ b/compiler/rustc_codegen_ssa/src/common.rs
@@ -42,7 +42,7 @@ pub enum RealPredicate {
     RealPredicateTrue,
 }
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, PartialEq)]
 pub enum AtomicRmwBinOp {
     AtomicXchg,
     AtomicAdd,
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index d3f5de25d9a..9bb2a528265 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -1237,6 +1237,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         }
     }
 
+    pub fn codegen_block_as_unreachable(&mut self, bb: mir::BasicBlock) {
+        let llbb = match self.try_llbb(bb) {
+            Some(llbb) => llbb,
+            None => return,
+        };
+        let bx = &mut Bx::build(self.cx, llbb);
+        debug!("codegen_block_as_unreachable({:?})", bb);
+        bx.unreachable();
+    }
+
     fn codegen_terminator(
         &mut self,
         bx: &mut Bx,
diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
index 82488829b6e..1d1826d9844 100644
--- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
@@ -350,14 +350,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
                             let weak = instruction == "cxchgweak";
                             let dst = args[0].immediate();
-                            let mut cmp = args[1].immediate();
-                            let mut src = args[2].immediate();
-                            if ty.is_unsafe_ptr() {
-                                // Some platforms do not support atomic operations on pointers,
-                                // so we cast to integer first.
-                                cmp = bx.ptrtoint(cmp, bx.type_isize());
-                                src = bx.ptrtoint(src, bx.type_isize());
-                            }
+                            let cmp = args[1].immediate();
+                            let src = args[2].immediate();
                             let (val, success) = bx.atomic_cmpxchg(
                                 dst,
                                 cmp,
@@ -385,26 +379,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             let layout = bx.layout_of(ty);
                             let size = layout.size;
                             let source = args[0].immediate();
-                            if ty.is_unsafe_ptr() {
-                                // Some platforms do not support atomic operations on pointers,
-                                // so we cast to integer first...
-                                let llty = bx.type_isize();
-                                let result = bx.atomic_load(
-                                    llty,
-                                    source,
-                                    parse_ordering(bx, ordering),
-                                    size,
-                                );
-                                // ... and then cast the result back to a pointer
-                                bx.inttoptr(result, bx.backend_type(layout))
-                            } else {
-                                bx.atomic_load(
-                                    bx.backend_type(layout),
-                                    source,
-                                    parse_ordering(bx, ordering),
-                                    size,
-                                )
-                            }
+                            bx.atomic_load(
+                                bx.backend_type(layout),
+                                source,
+                                parse_ordering(bx, ordering),
+                                size,
+                            )
                         } else {
                             invalid_monomorphization(ty);
                             return Ok(());
@@ -415,13 +395,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         let ty = fn_args.type_at(0);
                         if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
                             let size = bx.layout_of(ty).size;
-                            let mut val = args[1].immediate();
+                            let val = args[1].immediate();
                             let ptr = args[0].immediate();
-                            if ty.is_unsafe_ptr() {
-                                // Some platforms do not support atomic operations on pointers,
-                                // so we cast to integer first.
-                                val = bx.ptrtoint(val, bx.type_isize());
-                            }
                             bx.atomic_store(val, ptr, parse_ordering(bx, ordering), size);
                         } else {
                             invalid_monomorphization(ty);
@@ -465,12 +440,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         let ty = fn_args.type_at(0);
                         if int_type_width_signed(ty, bx.tcx()).is_some() || ty.is_unsafe_ptr() {
                             let ptr = args[0].immediate();
-                            let mut val = args[1].immediate();
-                            if ty.is_unsafe_ptr() {
-                                // Some platforms do not support atomic operations on pointers,
-                                // so we cast to integer first.
-                                val = bx.ptrtoint(val, bx.type_isize());
-                            }
+                            let val = args[1].immediate();
                             bx.atomic_rmw(atom_op, ptr, val, parse_ordering(bx, ordering))
                         } else {
                             invalid_monomorphization(ty);
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index a6fcf1fd38c..bac10f31336 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -256,13 +256,22 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     // Apply debuginfo to the newly allocated locals.
     fx.debug_introduce_locals(&mut start_bx);
 
+    let reachable_blocks = mir.reachable_blocks_in_mono(cx.tcx(), instance);
+
     // The builders will be created separately for each basic block at `codegen_block`.
     // So drop the builder of `start_llbb` to avoid having two at the same time.
     drop(start_bx);
 
     // Codegen the body of each block using reverse postorder
     for (bb, _) in traversal::reverse_postorder(mir) {
-        fx.codegen_block(bb);
+        if reachable_blocks.contains(bb) {
+            fx.codegen_block(bb);
+        } else {
+            // This may have references to things we didn't monomorphize, so we
+            // don't actually codegen the body. We still create the block so
+            // terminators in other blocks can reference it without worry.
+            fx.codegen_block_as_unreachable(bb);
+        }
     }
 }
 
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index 8c6b9faf39d..8159f76b421 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -306,11 +306,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 bx.bitcast(imm, to_backend_ty)
             }
             (Pointer(..), Pointer(..)) => bx.pointercast(imm, to_backend_ty),
-            (Int(..), Pointer(..)) => bx.inttoptr(imm, to_backend_ty),
+            (Int(..), Pointer(..)) => bx.ptradd(bx.const_null(bx.type_ptr()), imm),
             (Pointer(..), Int(..)) => bx.ptrtoint(imm, to_backend_ty),
             (F16 | F32 | F64 | F128, Pointer(..)) => {
                 let int_imm = bx.bitcast(imm, bx.cx().type_isize());
-                bx.inttoptr(int_imm, to_backend_ty)
+                bx.ptradd(bx.const_null(bx.type_ptr()), int_imm)
             }
             (Pointer(..), F16 | F32 | F64 | F128) => {
                 let int_imm = bx.ptrtoint(imm, bx.cx().type_isize());
diff --git a/compiler/rustc_codegen_ssa/src/mono_item.rs b/compiler/rustc_codegen_ssa/src/mono_item.rs
index 1a4795c0213..7b7cdae0ed6 100644
--- a/compiler/rustc_codegen_ssa/src/mono_item.rs
+++ b/compiler/rustc_codegen_ssa/src/mono_item.rs
@@ -30,7 +30,7 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
 
         match *self {
             MonoItem::Static(def_id) => {
-                cx.codegen_static(def_id, cx.tcx().is_mutable_static(def_id));
+                cx.codegen_static(def_id);
             }
             MonoItem::GlobalAsm(item_id) => {
                 let item = cx.tcx().hir().item(item_id);
diff --git a/compiler/rustc_codegen_ssa/src/traits/statics.rs b/compiler/rustc_codegen_ssa/src/traits/statics.rs
index 413d31bb942..737d93fd80a 100644
--- a/compiler/rustc_codegen_ssa/src/traits/statics.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/statics.rs
@@ -4,7 +4,7 @@ use rustc_target::abi::Align;
 
 pub trait StaticMethods: BackendTypes {
     fn static_addr_of(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value;
-    fn codegen_static(&self, def_id: DefId, is_mutable: bool);
+    fn codegen_static(&self, def_id: DefId);
 
     /// Mark the given global value as "used", to prevent the compiler and linker from potentially
     /// removing a static variable that may otherwise appear unused.