Auto merge of #150810 - matthiaskrgr:rollup-fXh6V3q, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - #149976 (Add waker_fn and local_waker_fn to std::task)
 - #150074 (Update provider API docs)
 - #150094 (`c_variadic`: provide our own `va_arg` implementation for more targets)
 - #150164 (rustc: Fix `-Zexport-executable-symbols` on wasm)
 - #150569 (Ensure that static initializers are acyclic for NVPTX)
 - #150694 (./x check miri: enable check_only feature)
 - #150717 (Thread `--jobs` from `bootstrap` -> `compiletest` -> `run-make-support`)
 - #150736 (Add AtomicPtr::null)
 - #150787 (Add myself as co-maintainer for s390x-unknown-linux-musl)
 - #150789 (Fix copy-n-paste error in `vtable_for` docs)

r? @ghost

Author: rust-bors[bot]

Cargo.lock

@@ -4421,6 +4421,7 @@ dependencies = [
  "rustc_errors",
  "rustc_fluent_macro",
  "rustc_hir",
+ "rustc_index",
  "rustc_macros",
  "rustc_middle",
  "rustc_session",

compiler/rustc_codegen_llvm/src/va_arg.rs

@@ -1,12 +1,13 @@
-use rustc_abi::{Align, BackendRepr, Endian, HasDataLayout, Primitive, Size, TyAndLayout};
+use rustc_abi::{Align, BackendRepr, Endian, HasDataLayout, Primitive, Size};
 use rustc_codegen_ssa::MemFlags;
 use rustc_codegen_ssa::common::IntPredicate;
 use rustc_codegen_ssa::mir::operand::OperandRef;
 use rustc_codegen_ssa::traits::{
     BaseTypeCodegenMethods, BuilderMethods, ConstCodegenMethods, LayoutTypeCodegenMethods,
 };
+use rustc_middle::bug;
 use rustc_middle::ty::Ty;
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
 use rustc_target::spec::{Abi, Arch, Env};
 
 use crate::builder::Builder;
@@ -82,6 +83,7 @@ enum PassMode {
 enum SlotSize {
     Bytes8 = 8,
     Bytes4 = 4,
+    Bytes1 = 1,
 }
 
 enum AllowHigherAlign {
@@ -728,7 +730,7 @@ fn emit_x86_64_sysv64_va_arg<'ll, 'tcx>(
 fn copy_to_temporary_if_more_aligned<'ll, 'tcx>(
     bx: &mut Builder<'_, 'll, 'tcx>,
     reg_addr: &'ll Value,
-    layout: TyAndLayout<'tcx, Ty<'tcx>>,
+    layout: TyAndLayout<'tcx>,
     src_align: Align,
 ) -> &'ll Value {
     if layout.layout.align.abi > src_align {
@@ -751,7 +753,7 @@ fn copy_to_temporary_if_more_aligned<'ll, 'tcx>(
 fn x86_64_sysv64_va_arg_from_memory<'ll, 'tcx>(
     bx: &mut Builder<'_, 'll, 'tcx>,
     va_list_addr: &'ll Value,
-    layout: TyAndLayout<'tcx, Ty<'tcx>>,
+    layout: TyAndLayout<'tcx>,
 ) -> &'ll Value {
     let dl = bx.cx.data_layout();
     let ptr_align_abi = dl.data_layout().pointer_align().abi;
@@ -1003,15 +1005,17 @@ fn emit_xtensa_va_arg<'ll, 'tcx>(
     return bx.load(layout.llvm_type(bx), value_ptr, layout.align.abi);
 }
 
+/// Determine the va_arg implementation to use. The LLVM va_arg instruction
+/// is lacking in some instances, so we should only use it as a fallback.
 pub(super) fn emit_va_arg<'ll, 'tcx>(
     bx: &mut Builder<'_, 'll, 'tcx>,
     addr: OperandRef<'tcx, &'ll Value>,
     target_ty: Ty<'tcx>,
 ) -> &'ll Value {
-    // Determine the va_arg implementation to use. The LLVM va_arg instruction
-    // is lacking in some instances, so we should only use it as a fallback.
-    let target = &bx.cx.tcx.sess.target;
+    let layout = bx.cx.layout_of(target_ty);
+    let target_ty_size = layout.layout.size().bytes();
 
+    let target = &bx.cx.tcx.sess.target;
     match target.arch {
         Arch::X86 => emit_ptr_va_arg(
             bx,
@@ -1069,23 +1073,79 @@ pub(super) fn emit_va_arg<'ll, 'tcx>(
             AllowHigherAlign::Yes,
             ForceRightAdjust::No,
         ),
+        Arch::LoongArch32 => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            if target_ty_size > 2 * 4 { PassMode::Indirect } else { PassMode::Direct },
+            SlotSize::Bytes4,
+            AllowHigherAlign::Yes,
+            ForceRightAdjust::No,
+        ),
+        Arch::LoongArch64 => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            if target_ty_size > 2 * 8 { PassMode::Indirect } else { PassMode::Direct },
+            SlotSize::Bytes8,
+            AllowHigherAlign::Yes,
+            ForceRightAdjust::No,
+        ),
+        Arch::AmdGpu => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            PassMode::Direct,
+            SlotSize::Bytes4,
+            AllowHigherAlign::No,
+            ForceRightAdjust::No,
+        ),
+        Arch::Nvptx64 => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            PassMode::Direct,
+            SlotSize::Bytes1,
+            AllowHigherAlign::Yes,
+            ForceRightAdjust::No,
+        ),
+        Arch::Wasm32 => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            if layout.is_aggregate() || layout.is_zst() || layout.is_1zst() {
+                PassMode::Indirect
+            } else {
+                PassMode::Direct
+            },
+            SlotSize::Bytes4,
+            AllowHigherAlign::Yes,
+            ForceRightAdjust::No,
+        ),
+        Arch::Wasm64 => bug!("c-variadic functions are not fully implemented for wasm64"),
+        Arch::CSky => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            PassMode::Direct,
+            SlotSize::Bytes4,
+            AllowHigherAlign::Yes,
+            ForceRightAdjust::No,
+        ),
         // Windows x86_64
-        Arch::X86_64 if target.is_like_windows => {
-            let target_ty_size = bx.cx.size_of(target_ty).bytes();
-            emit_ptr_va_arg(
-                bx,
-                addr,
-                target_ty,
-                if target_ty_size > 8 || !target_ty_size.is_power_of_two() {
-                    PassMode::Indirect
-                } else {
-                    PassMode::Direct
-                },
-                SlotSize::Bytes8,
-                AllowHigherAlign::No,
-                ForceRightAdjust::No,
-            )
-        }
+        Arch::X86_64 if target.is_like_windows => emit_ptr_va_arg(
+            bx,
+            addr,
+            target_ty,
+            if target_ty_size > 8 || !target_ty_size.is_power_of_two() {
+                PassMode::Indirect
+            } else {
+                PassMode::Direct
+            },
+            SlotSize::Bytes8,
+            AllowHigherAlign::No,
+            ForceRightAdjust::No,
+        ),
         // This includes `target.is_like_darwin`, which on x86_64 targets is like sysv64.
         Arch::X86_64 => emit_x86_64_sysv64_va_arg(bx, addr, target_ty),
         Arch::Xtensa => emit_xtensa_va_arg(bx, addr, target_ty),

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -839,6 +839,11 @@ impl<'a> Linker for GccLinker<'a> {
                 self.sess.dcx().emit_fatal(errors::LibDefWriteFailure { error });
             }
             self.link_arg(path);
+        } else if self.sess.target.is_like_wasm {
+            self.link_arg("--no-export-dynamic");
+            for (sym, _) in symbols {
+                self.link_arg("--export").link_arg(sym);
+            }
         } else if crate_type == CrateType::Executable && !self.sess.target.is_like_solaris {
             let res: io::Result<()> = try {
                 let mut f = File::create_buffered(&path)?;
@@ -853,11 +858,6 @@ impl<'a> Linker for GccLinker<'a> {
                 self.sess.dcx().emit_fatal(errors::VersionScriptWriteFailure { error });
             }
             self.link_arg("--dynamic-list").link_arg(path);
-        } else if self.sess.target.is_like_wasm {
-            self.link_arg("--no-export-dynamic");
-            for (sym, _) in symbols {
-                self.link_arg("--export").link_arg(sym);
-            }
         } else {
             // Write an LD version script
             let res: io::Result<()> = try {

compiler/rustc_monomorphize/Cargo.toml

@@ -10,6 +10,7 @@ rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_hir = { path = "../rustc_hir" }
+rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_session = { path = "../rustc_session" }

compiler/rustc_monomorphize/messages.ftl

@@ -75,4 +75,8 @@ monomorphize_recursion_limit =
 monomorphize_start_not_found = using `fn main` requires the standard library
     .help = use `#![no_main]` to bypass the Rust generated entrypoint and declare a platform specific entrypoint yourself, usually with `#[no_mangle]`
 
+monomorphize_static_initializer_cyclic =  static initializer forms a cycle involving `{$head}`
+    .label = part of this cycle
+    .note = cyclic static initializers are not supported for target `{$target}`
+
 monomorphize_symbol_already_defined = symbol `{$symbol}` is already defined

compiler/rustc_monomorphize/src/collector.rs

@@ -267,7 +267,8 @@ pub(crate) struct UsageMap<'tcx> {
     // Maps every mono item to the mono items used by it.
     pub used_map: UnordMap<MonoItem<'tcx>, Vec<MonoItem<'tcx>>>,
 
-    // Maps every mono item to the mono items that use it.
+    // Maps each mono item with users to the mono items that use it.
+    // Be careful: subsets `used_map`, so unused items are vacant.
     user_map: UnordMap<MonoItem<'tcx>, Vec<MonoItem<'tcx>>>,
 }
 

compiler/rustc_monomorphize/src/errors.rs

@@ -117,3 +117,15 @@ pub(crate) struct AbiRequiredTargetFeature<'a> {
     /// Whether this is a problem at a call site or at a declaration.
     pub is_call: bool,
 }
+
+#[derive(Diagnostic)]
+#[diag(monomorphize_static_initializer_cyclic)]
+#[note]
+pub(crate) struct StaticInitializerCyclic<'a> {
+    #[primary_span]
+    pub span: Span,
+    #[label]
+    pub labels: Vec<Span>,
+    pub head: &'a str,
+    pub target: &'a str,
+}

compiler/rustc_monomorphize/src/graph_checks/mod.rs

@@ -0,0 +1,18 @@
+//! Checks that need to operate on the entire mono item graph
+use rustc_middle::mir::mono::MonoItem;
+use rustc_middle::ty::TyCtxt;
+
+use crate::collector::UsageMap;
+use crate::graph_checks::statics::check_static_initializers_are_acyclic;
+
+mod statics;
+
+pub(super) fn target_specific_checks<'tcx, 'a, 'b>(
+    tcx: TyCtxt<'tcx>,
+    mono_items: &'a [MonoItem<'tcx>],
+    usage_map: &'b UsageMap<'tcx>,
+) {
+    if tcx.sess.target.options.static_initializer_must_be_acyclic {
+        check_static_initializers_are_acyclic(tcx, mono_items, usage_map);
+    }
+}

compiler/rustc_monomorphize/src/graph_checks/statics.rs

@@ -0,0 +1,115 @@
+use rustc_data_structures::fx::FxIndexSet;
+use rustc_data_structures::graph::scc::Sccs;
+use rustc_data_structures::graph::{DirectedGraph, Successors};
+use rustc_data_structures::unord::UnordMap;
+use rustc_hir::def_id::DefId;
+use rustc_index::{Idx, IndexVec, newtype_index};
+use rustc_middle::mir::mono::MonoItem;
+use rustc_middle::ty::TyCtxt;
+
+use crate::collector::UsageMap;
+use crate::errors;
+
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+struct StaticNodeIdx(usize);
+
+impl Idx for StaticNodeIdx {
+    fn new(idx: usize) -> Self {
+        Self(idx)
+    }
+
+    fn index(self) -> usize {
+        self.0
+    }
+}
+
+impl From<usize> for StaticNodeIdx {
+    fn from(value: usize) -> Self {
+        StaticNodeIdx(value)
+    }
+}
+
+newtype_index! {
+    #[derive(Ord, PartialOrd)]
+    struct StaticSccIdx {}
+}
+
+// Adjacency-list graph for statics using `StaticNodeIdx` as node type.
+// We cannot use `DefId` as the node type directly because each node must be
+// represented by an index in the range `0..num_nodes`.
+struct StaticRefGraph<'a, 'b, 'tcx> {
+    // maps from `StaticNodeIdx` to `DefId` and vice versa
+    statics: &'a FxIndexSet<DefId>,
+    // contains for each `MonoItem` the `MonoItem`s it uses
+    used_map: &'b UnordMap<MonoItem<'tcx>, Vec<MonoItem<'tcx>>>,
+}
+
+impl<'a, 'b, 'tcx> DirectedGraph for StaticRefGraph<'a, 'b, 'tcx> {
+    type Node = StaticNodeIdx;
+
+    fn num_nodes(&self) -> usize {
+        self.statics.len()
+    }
+}
+
+impl<'a, 'b, 'tcx> Successors for StaticRefGraph<'a, 'b, 'tcx> {
+    fn successors(&self, node_idx: StaticNodeIdx) -> impl Iterator<Item = StaticNodeIdx> {
+        let def_id = self.statics[node_idx.index()];
+        self.used_map[&MonoItem::Static(def_id)].iter().filter_map(|&mono_item| match mono_item {
+            MonoItem::Static(def_id) => self.statics.get_index_of(&def_id).map(|idx| idx.into()),
+            _ => None,
+        })
+    }
+}
+
+pub(super) fn check_static_initializers_are_acyclic<'tcx, 'a, 'b>(
+    tcx: TyCtxt<'tcx>,
+    mono_items: &'a [MonoItem<'tcx>],
+    usage_map: &'b UsageMap<'tcx>,
+) {
+    // Collect statics
+    let statics: FxIndexSet<DefId> = mono_items
+        .iter()
+        .filter_map(|&mono_item| match mono_item {
+            MonoItem::Static(def_id) => Some(def_id),
+            _ => None,
+        })
+        .collect();
+
+    // If we don't have any statics the check is not necessary
+    if statics.is_empty() {
+        return;
+    }
+    // Create a subgraph from the mono item graph, which only contains statics
+    let graph = StaticRefGraph { statics: &statics, used_map: &usage_map.used_map };
+    // Calculate its SCCs
+    let sccs: Sccs<StaticNodeIdx, StaticSccIdx> = Sccs::new(&graph);
+    // Group statics by SCCs
+    let mut nodes_of_sccs: IndexVec<StaticSccIdx, Vec<StaticNodeIdx>> =
+        IndexVec::from_elem_n(Vec::new(), sccs.num_sccs());
+    for i in graph.iter_nodes() {
+        nodes_of_sccs[sccs.scc(i)].push(i);
+    }
+    let is_cyclic = |nodes_of_scc: &[StaticNodeIdx]| -> bool {
+        match nodes_of_scc.len() {
+            0 => false,
+            1 => graph.successors(nodes_of_scc[0]).any(|x| x == nodes_of_scc[0]),
+            2.. => true,
+        }
+    };
+    // Emit errors for all cycles
+    for nodes in nodes_of_sccs.iter_mut().filter(|nodes| is_cyclic(nodes)) {
+        // We sort the nodes by their Span to have consistent error line numbers
+        nodes.sort_by_key(|node| tcx.def_span(statics[node.index()]));
+
+        let head_def = statics[nodes[0].index()];
+        let head_span = tcx.def_span(head_def);
+
+        tcx.dcx().emit_err(errors::StaticInitializerCyclic {
+            span: head_span,
+            labels: nodes.iter().map(|&n| tcx.def_span(statics[n.index()])).collect(),
+            head: &tcx.def_path_str(head_def),
+            target: &tcx.sess.target.llvm_target,
+        });
+    }
+}

compiler/rustc_monomorphize/src/lib.rs

@@ -16,6 +16,7 @@ use rustc_span::ErrorGuaranteed;
 
 mod collector;
 mod errors;
+mod graph_checks;
 mod mono_checks;
 mod partitioning;
 mod util;