Auto merge of #65495 - Centril:rollup-tguwjt5, r=Centril

Rollup of 8 pull requests

Successful merges:

 - #65237 (Move debug_map assertions after check for err)
 - #65316 (make File::try_clone produce non-inheritable handles on Windows)
 - #65319 (InterpCx: make memory field public)
 - #65461 (Don't recommend ONCE_INIT in std::sync::Once)
 - #65465 (Move syntax::ext to a syntax_expand and refactor some attribute logic)
 - #65475 (add example for type_name)
 - #65478 (fmt::Write is about string slices, not byte slices)
 - #65486 (doc: fix typo in OsStrExt and OsStringExt)

Failed merges:

r? @ghost

1 files changed, 75 insertions, 0 deletions

diff --git a/src/libsyntax_expand/allocator.rs b/src/libsyntax_expand/allocator.rs
new file mode 100644
index 00000000000..3526be17721
--- /dev/null
+++ b/src/libsyntax_expand/allocator.rs
@@ -0,0 +1,75 @@
+use syntax::{ast, attr, visit};
+use syntax::symbol::{sym, Symbol};
+use syntax_pos::Span;
+
+#[derive(Clone, Copy)]
+pub enum AllocatorKind {
+    Global,
+    DefaultLib,
+    DefaultExe,
+}
+
+impl AllocatorKind {
+    pub fn fn_name(&self, base: &str) -> String {
+        match *self {
+            AllocatorKind::Global => format!("__rg_{}", base),
+            AllocatorKind::DefaultLib => format!("__rdl_{}", base),
+            AllocatorKind::DefaultExe => format!("__rde_{}", base),
+        }
+    }
+}
+
+pub enum AllocatorTy {
+    Layout,
+    Ptr,
+    ResultPtr,
+    Unit,
+    Usize,
+}
+
+pub struct AllocatorMethod {
+    pub name: &'static str,
+    pub inputs: &'static [AllocatorTy],
+    pub output: AllocatorTy,
+}
+
+pub static ALLOCATOR_METHODS: &[AllocatorMethod] = &[
+    AllocatorMethod {
+        name: "alloc",
+        inputs: &[AllocatorTy::Layout],
+        output: AllocatorTy::ResultPtr,
+    },
+    AllocatorMethod {
+        name: "dealloc",
+        inputs: &[AllocatorTy::Ptr, AllocatorTy::Layout],
+        output: AllocatorTy::Unit,
+    },
+    AllocatorMethod {
+        name: "realloc",
+        inputs: &[AllocatorTy::Ptr, AllocatorTy::Layout, AllocatorTy::Usize],
+        output: AllocatorTy::ResultPtr,
+    },
+    AllocatorMethod {
+        name: "alloc_zeroed",
+        inputs: &[AllocatorTy::Layout],
+        output: AllocatorTy::ResultPtr,
+    },
+];
+
+pub fn global_allocator_spans(krate: &ast::Crate) -> Vec<Span> {
+    struct Finder { name: Symbol, spans: Vec<Span> }
+    impl<'ast> visit::Visitor<'ast> for Finder {
+        fn visit_item(&mut self, item: &'ast ast::Item) {
+            if item.ident.name == self.name &&
+               attr::contains_name(&item.attrs, sym::rustc_std_internal_symbol) {
+                self.spans.push(item.span);
+            }
+            visit::walk_item(self, item)
+        }
+    }
+
+    let name = Symbol::intern(&AllocatorKind::Global.fn_name("alloc"));
+    let mut f = Finder { name, spans: Vec::new() };
+    visit::walk_crate(&mut f, krate);
+    f.spans
+}