Move /src/test to /tests

tests/codegen-units/item-collection/asm-sym.rs

@@ -0,0 +1,20 @@
+// needs-asm-support
+// compile-flags: -Ccodegen-units=1 -Zprint-mono-items=lazy --crate-type=lib
+
+#[inline(always)]
+pub unsafe fn f() {
+    //~ MONO_ITEM static f::S @@ asm_sym-cgu.0[External]
+    static S: usize = 1;
+    //~ MONO_ITEM fn f::fun @@ asm_sym-cgu.0[External]
+    fn fun() {}
+    core::arch::asm!("/* {0} {1} */", sym S, sym fun);
+}
+
+//~ MONO_ITEM fn g @@ asm_sym-cgu.0[External]
+pub unsafe fn g() {
+    //~ MONO_ITEM static g::S @@ asm_sym-cgu.0[Internal]
+    static S: usize = 2;
+    //~ MONO_ITEM fn g::fun @@ asm_sym-cgu.0[Internal]
+    fn fun() {}
+    core::arch::asm!("/* {0} {1} */", sym S, sym fun);
+}

tests/codegen-units/item-collection/auxiliary/cgu_export_trait_method.rs

@@ -0,0 +1,24 @@
+#![crate_type = "lib"]
+
+pub trait Trait : Sized {
+    fn without_self() -> u32;
+    fn without_self_default() -> u32 { 0 }
+
+    fn with_default_impl(self) -> Self { self }
+    fn with_default_impl_generic<T>(self, x: T) -> (Self, T) { (self, x) }
+
+    fn without_default_impl(x: u32) -> (Self, u32);
+    fn without_default_impl_generic<T>(x: T) -> (Self, T);
+}
+
+impl Trait for char {
+    fn without_self() -> u32 { 2 }
+    fn without_default_impl(x: u32) -> (Self, u32) { ('c', x) }
+    fn without_default_impl_generic<T>(x: T) -> (Self, T) { ('c', x) }
+}
+
+impl Trait for u32 {
+    fn without_self() -> u32 { 1 }
+    fn without_default_impl(x: u32) -> (Self, u32) { (0, x) }
+    fn without_default_impl_generic<T>(x: T) -> (Self, T) { (0, x) }
+}

tests/codegen-units/item-collection/auxiliary/cgu_extern_closures.rs

@@ -0,0 +1,23 @@
+#![crate_type = "lib"]
+
+#[inline]
+pub fn inlined_fn(x: i32, y: i32) -> i32 {
+
+    let closure = |a, b| { a + b };
+
+    closure(x, y)
+}
+
+pub fn inlined_fn_generic<T>(x: i32, y: i32, z: T) -> (i32, T) {
+
+    let closure = |a, b| { a + b };
+
+    (closure(x, y), z)
+}
+
+pub fn non_inlined_fn(x: i32, y: i32) -> i32 {
+
+    let closure = |a, b| { a + b };
+
+    closure(x, y)
+}

tests/codegen-units/item-collection/auxiliary/cgu_generic_function.rs

@@ -0,0 +1,26 @@
+#![crate_type = "lib"]
+
+struct Struct(u32);
+
+#[inline(never)]
+pub fn foo<T>(x: T) -> (T, u32, i8) {
+    let (x, Struct(y)) = bar(x);
+    (x, y, 2)
+}
+
+#[inline(never)]
+fn bar<T>(x: T) -> (T, Struct) {
+    let _ = not_exported_and_not_generic(0);
+    (x, Struct(1))
+}
+
+// These should not contribute to the codegen items of other crates.
+#[inline(never)]
+pub fn exported_but_not_generic(x: i32) -> i64 {
+    x as i64
+}
+
+#[inline(never)]
+fn not_exported_and_not_generic(x: u32) -> u64 {
+    x as u64
+}

tests/codegen-units/item-collection/cross-crate-closures.rs

@@ -0,0 +1,33 @@
+// In the current version of the collector that still has to support
+// legacy-codegen, closures do not generate their own MonoItems, so we are
+// ignoring this test until MIR codegen has taken over completely
+// ignore-test
+
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+// aux-build:cgu_extern_closures.rs
+extern crate cgu_extern_closures;
+
+//~ MONO_ITEM fn cross_crate_closures::start[0]
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn[0]
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn[0]::{{closure}}[0]
+    let _ = cgu_extern_closures::inlined_fn(1, 2);
+
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic[0]<i32>
+    //~ MONO_ITEM fn cgu_extern_closures::inlined_fn_generic[0]::{{closure}}[0]<i32>
+    let _ = cgu_extern_closures::inlined_fn_generic(3, 4, 5i32);
+
+    // Nothing should be generated for this call, we just link to the instance
+    // in the extern crate.
+    let _ = cgu_extern_closures::non_inlined_fn(6, 7);
+
+    0
+}
+
+//~ MONO_ITEM drop-glue i8

tests/codegen-units/item-collection/cross-crate-generic-functions.rs

@@ -0,0 +1,24 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+// aux-build:cgu_generic_function.rs
+extern crate cgu_generic_function;
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn cgu_generic_function::bar::<u32>
+    //~ MONO_ITEM fn cgu_generic_function::foo::<u32>
+    let _ = cgu_generic_function::foo(1u32);
+
+    //~ MONO_ITEM fn cgu_generic_function::bar::<u64>
+    //~ MONO_ITEM fn cgu_generic_function::foo::<u64>
+    let _ = cgu_generic_function::foo(2u64);
+
+    // This should not introduce a codegen item
+    let _ = cgu_generic_function::exported_but_not_generic(3);
+
+    0
+}

tests/codegen-units/item-collection/cross-crate-trait-method.rs

@@ -0,0 +1,50 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+// aux-build:cgu_export_trait_method.rs
+extern crate cgu_export_trait_method;
+
+use cgu_export_trait_method::Trait;
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    // The object code of these methods is contained in the external crate, so
+    // calling them should *not* introduce codegen items in the current crate.
+    let _: (u32, u32) = Trait::without_default_impl(0);
+    let _: (char, u32) = Trait::without_default_impl(0);
+
+    // Currently, no object code is generated for trait methods with default
+    // implementations, unless they are actually called from somewhere. Therefore
+    // we cannot import the implementations and have to create our own inline.
+    //~ MONO_ITEM fn <u32 as cgu_export_trait_method::Trait>::with_default_impl
+    let _ = Trait::with_default_impl(0u32);
+    //~ MONO_ITEM fn <char as cgu_export_trait_method::Trait>::with_default_impl
+    let _ = Trait::with_default_impl('c');
+
+
+
+    //~ MONO_ITEM fn <u32 as cgu_export_trait_method::Trait>::with_default_impl_generic::<&str>
+    let _ = Trait::with_default_impl_generic(0u32, "abc");
+    //~ MONO_ITEM fn <u32 as cgu_export_trait_method::Trait>::with_default_impl_generic::<bool>
+    let _ = Trait::with_default_impl_generic(0u32, false);
+
+    //~ MONO_ITEM fn <char as cgu_export_trait_method::Trait>::with_default_impl_generic::<i16>
+    let _ = Trait::with_default_impl_generic('x', 1i16);
+    //~ MONO_ITEM fn <char as cgu_export_trait_method::Trait>::with_default_impl_generic::<i32>
+    let _ = Trait::with_default_impl_generic('y', 0i32);
+
+    //~ MONO_ITEM fn <u32 as cgu_export_trait_method::Trait>::without_default_impl_generic::<char>
+    let _: (u32, char) = Trait::without_default_impl_generic('c');
+    //~ MONO_ITEM fn <u32 as cgu_export_trait_method::Trait>::without_default_impl_generic::<bool>
+    let _: (u32, bool) = Trait::without_default_impl_generic(false);
+
+    //~ MONO_ITEM fn <char as cgu_export_trait_method::Trait>::without_default_impl_generic::<char>
+    let _: (char, char) = Trait::without_default_impl_generic('c');
+    //~ MONO_ITEM fn <char as cgu_export_trait_method::Trait>::without_default_impl_generic::<bool>
+    let _: (char, bool) = Trait::without_default_impl_generic(false);
+
+    0
+}

tests/codegen-units/item-collection/drop_in_place_intrinsic.rs

@@ -0,0 +1,36 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+
+#![feature(start)]
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDtor> - shim(Some(StructWithDtor)) @@ drop_in_place_intrinsic-cgu.0[Internal]
+struct StructWithDtor(u32);
+
+impl Drop for StructWithDtor {
+    //~ MONO_ITEM fn <StructWithDtor as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<[StructWithDtor; 2]> - shim(Some([StructWithDtor; 2])) @@ drop_in_place_intrinsic-cgu.0[Internal]
+    let x = [StructWithDtor(0), StructWithDtor(1)];
+
+    drop_slice_in_place(&x);
+
+    0
+}
+
+//~ MONO_ITEM fn drop_slice_in_place
+fn drop_slice_in_place(x: &[StructWithDtor]) {
+    unsafe {
+        // This is the interesting thing in this test case: Normally we would
+        // not have drop-glue for the unsized [StructWithDtor]. This has to be
+        // generated though when the drop_in_place() intrinsic is used.
+        //~ MONO_ITEM fn std::ptr::drop_in_place::<[StructWithDtor]> - shim(Some([StructWithDtor])) @@ drop_in_place_intrinsic-cgu.0[Internal]
+        ::std::ptr::drop_in_place(x as *const _ as *mut [StructWithDtor]);
+    }
+}

tests/codegen-units/item-collection/function-as-argument.rs

@@ -0,0 +1,40 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+fn take_fn_once<T1, T2, F: FnOnce(T1, T2)>(f: F, x: T1, y: T2) {
+    (f)(x, y)
+}
+
+fn function<T1, T2>(_: T1, _: T2) {}
+
+fn take_fn_pointer<T1, T2>(f: fn(T1, T2), x: T1, y: T2) {
+    (f)(x, y)
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+
+    //~ MONO_ITEM fn take_fn_once::<u32, &str, fn(u32, &str) {function::<u32, &str>}>
+    //~ MONO_ITEM fn function::<u32, &str>
+    //~ MONO_ITEM fn <fn(u32, &str) {function::<u32, &str>} as std::ops::FnOnce<(u32, &str)>>::call_once - shim(fn(u32, &str) {function::<u32, &str>})
+    take_fn_once(function, 0u32, "abc");
+
+    //~ MONO_ITEM fn take_fn_once::<char, f64, fn(char, f64) {function::<char, f64>}>
+    //~ MONO_ITEM fn function::<char, f64>
+    //~ MONO_ITEM fn <fn(char, f64) {function::<char, f64>} as std::ops::FnOnce<(char, f64)>>::call_once - shim(fn(char, f64) {function::<char, f64>})
+    take_fn_once(function, 'c', 0f64);
+
+    //~ MONO_ITEM fn take_fn_pointer::<i32, ()>
+    //~ MONO_ITEM fn function::<i32, ()>
+    take_fn_pointer(function, 0i32, ());
+
+    //~ MONO_ITEM fn take_fn_pointer::<f32, i64>
+    //~ MONO_ITEM fn function::<f32, i64>
+    take_fn_pointer(function, 0f32, 0i64);
+
+    0
+}

tests/codegen-units/item-collection/generic-drop-glue.rs

@@ -0,0 +1,91 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+
+#![deny(dead_code)]
+#![feature(start)]
+
+struct StructWithDrop<T1, T2> {
+    x: T1,
+    y: T2,
+}
+
+impl<T1, T2> Drop for StructWithDrop<T1, T2> {
+    fn drop(&mut self) {}
+}
+
+struct StructNoDrop<T1, T2> {
+    x: T1,
+    y: T2,
+}
+
+enum EnumWithDrop<T1, T2> {
+    A(T1),
+    B(T2)
+}
+
+impl<T1, T2> Drop for EnumWithDrop<T1, T2> {
+    fn drop(&mut self) {}
+}
+
+enum EnumNoDrop<T1, T2> {
+    A(T1),
+    B(T2)
+}
+
+
+struct NonGenericNoDrop(#[allow(unused_tuple_struct_fields)] i32);
+
+struct NonGenericWithDrop(#[allow(unused_tuple_struct_fields)] i32);
+//~ MONO_ITEM fn std::ptr::drop_in_place::<NonGenericWithDrop> - shim(Some(NonGenericWithDrop)) @@ generic_drop_glue-cgu.0[Internal]
+
+impl Drop for NonGenericWithDrop {
+    //~ MONO_ITEM fn <NonGenericWithDrop as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop<i8, char>> - shim(Some(StructWithDrop<i8, char>)) @@ generic_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <StructWithDrop<i8, char> as std::ops::Drop>::drop
+    let _ = StructWithDrop { x: 0i8, y: 'a' }.x;
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop<&str, NonGenericNoDrop>> - shim(Some(StructWithDrop<&str, NonGenericNoDrop>)) @@ generic_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <StructWithDrop<&str, NonGenericNoDrop> as std::ops::Drop>::drop
+    let _ = StructWithDrop { x: "&str", y: NonGenericNoDrop(0) }.y;
+
+    // Should produce no drop glue
+    let _ = StructNoDrop { x: 'a', y: 0u32 }.x;
+
+    // This is supposed to generate drop-glue because it contains a field that
+    // needs to be dropped.
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<StructNoDrop<NonGenericWithDrop, f64>> - shim(Some(StructNoDrop<NonGenericWithDrop, f64>)) @@ generic_drop_glue-cgu.0[Internal]
+    let _ = StructNoDrop { x: NonGenericWithDrop(0), y: 0f64 }.y;
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<EnumWithDrop<i32, i64>> - shim(Some(EnumWithDrop<i32, i64>)) @@ generic_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <EnumWithDrop<i32, i64> as std::ops::Drop>::drop
+    let _ = match EnumWithDrop::A::<i32, i64>(0) {
+        EnumWithDrop::A(x) => x,
+        EnumWithDrop::B(x) => x as i32
+    };
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<EnumWithDrop<f64, f32>> - shim(Some(EnumWithDrop<f64, f32>)) @@ generic_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <EnumWithDrop<f64, f32> as std::ops::Drop>::drop
+    let _ = match EnumWithDrop::B::<f64, f32>(1.0) {
+        EnumWithDrop::A(x) => x,
+        EnumWithDrop::B(x) => x as f64
+    };
+
+    let _ = match EnumNoDrop::A::<i32, i64>(0) {
+        EnumNoDrop::A(x) => x,
+        EnumNoDrop::B(x) => x as i32
+    };
+
+    let _ = match EnumNoDrop::B::<f64, f32>(1.0) {
+        EnumNoDrop::A(x) => x,
+        EnumNoDrop::B(x) => x as f64
+    };
+
+    0
+}

tests/codegen-units/item-collection/generic-functions.rs

@@ -0,0 +1,55 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+fn foo1<T1>(a: T1) -> (T1, u32) {
+    (a, 1)
+}
+
+fn foo2<T1, T2>(a: T1, b: T2) -> (T1, T2) {
+    (a, b)
+}
+
+fn foo3<T1, T2, T3>(a: T1, b: T2, c: T3) -> (T1, T2, T3) {
+    (a, b, c)
+}
+
+// This function should be instantiated even if no used
+//~ MONO_ITEM fn lifetime_only
+pub fn lifetime_only<'a>(a: &'a u32) -> &'a u32 {
+    a
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn foo1::<i32>
+    let _ = foo1(2i32);
+    //~ MONO_ITEM fn foo1::<i64>
+    let _ = foo1(2i64);
+    //~ MONO_ITEM fn foo1::<&str>
+    let _ = foo1("abc");
+    //~ MONO_ITEM fn foo1::<char>
+    let _ = foo1('v');
+
+    //~ MONO_ITEM fn foo2::<i32, i32>
+    let _ = foo2(2i32, 2i32);
+    //~ MONO_ITEM fn foo2::<i64, &str>
+    let _ = foo2(2i64, "abc");
+    //~ MONO_ITEM fn foo2::<&str, usize>
+    let _ = foo2("a", 2usize);
+    //~ MONO_ITEM fn foo2::<char, ()>
+    let _ = foo2('v', ());
+
+    //~ MONO_ITEM fn foo3::<i32, i32, i32>
+    let _ = foo3(2i32, 2i32, 2i32);
+    //~ MONO_ITEM fn foo3::<i64, &str, char>
+    let _ = foo3(2i64, "abc", 'c');
+    //~ MONO_ITEM fn foo3::<i16, &str, usize>
+    let _ = foo3(0i16, "a", 2usize);
+    //~ MONO_ITEM fn foo3::<char, (), ()>
+    let _ = foo3('v', (), ());
+
+    0
+}

tests/codegen-units/item-collection/generic-impl.rs

@@ -0,0 +1,71 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+struct Struct<T> {
+    x: T,
+    f: fn(x: T) -> T,
+}
+
+fn id<T>(x: T) -> T { x }
+
+impl<T> Struct<T> {
+
+    fn new(x: T) -> Struct<T> {
+        Struct {
+            x: x,
+            f: id
+        }
+    }
+
+    fn get<T2>(self, x: T2) -> (T, T2) {
+        (self.x, x)
+    }
+}
+
+pub struct LifeTimeOnly<'a> {
+    _a: &'a u32
+}
+
+impl<'a> LifeTimeOnly<'a> {
+
+    //~ MONO_ITEM fn LifeTimeOnly::<'_>::foo
+    pub fn foo(&self) {}
+    //~ MONO_ITEM fn LifeTimeOnly::<'_>::bar
+    pub fn bar(&'a self) {}
+    //~ MONO_ITEM fn LifeTimeOnly::<'_>::baz
+    pub fn baz<'b>(&'b self) {}
+
+    pub fn non_instantiated<T>(&self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn Struct::<i32>::new
+    //~ MONO_ITEM fn id::<i32>
+    //~ MONO_ITEM fn Struct::<i32>::get::<i16>
+    let _ = Struct::new(0i32).get(0i16);
+
+    //~ MONO_ITEM fn Struct::<i64>::new
+    //~ MONO_ITEM fn id::<i64>
+    //~ MONO_ITEM fn Struct::<i64>::get::<i16>
+    let _ = Struct::new(0i64).get(0i16);
+
+    //~ MONO_ITEM fn Struct::<char>::new
+    //~ MONO_ITEM fn id::<char>
+    //~ MONO_ITEM fn Struct::<char>::get::<i16>
+    let _ = Struct::new('c').get(0i16);
+
+    //~ MONO_ITEM fn Struct::<&str>::new
+    //~ MONO_ITEM fn id::<&str>
+    //~ MONO_ITEM fn Struct::<Struct<&str>>::get::<i16>
+    let _ = Struct::new(Struct::new("str")).get(0i16);
+
+    //~ MONO_ITEM fn Struct::<Struct<&str>>::new
+    //~ MONO_ITEM fn id::<Struct<&str>>
+    let _ = (Struct::new(Struct::new("str")).f)(Struct::new("str"));
+
+    0
+}

tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs

@@ -0,0 +1,27 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+trait SomeTrait {
+    fn foo(&self);
+}
+
+// This function is never instantiated but the contained impl must still be
+// discovered.
+pub fn generic_function<T>(x: T) -> (T, i32) {
+    impl SomeTrait for i64 {
+        //~ MONO_ITEM fn generic_function::<impl SomeTrait for i64>::foo
+        fn foo(&self) {}
+    }
+
+    (x, 0)
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    0i64.foo();
+
+    0
+}

tests/codegen-units/item-collection/implicit-panic-call.rs

@@ -0,0 +1,58 @@
+// compile-flags:-Zprint-mono-items=lazy
+
+// rust-lang/rust#90405
+// Ensure implicit panic calls are collected
+
+#![feature(lang_items)]
+#![feature(no_core)]
+#![crate_type = "lib"]
+#![no_core]
+#![no_std]
+
+#[lang = "panic_location"]
+struct Location<'a> {
+    _file: &'a str,
+    _line: u32,
+    _col: u32,
+}
+
+#[lang = "panic"]
+#[inline]
+#[track_caller]
+fn panic(_: &'static str) -> ! {
+    loop {}
+}
+
+#[lang = "sized"]
+trait Sized {}
+
+#[lang = "copy"]
+trait Copy {}
+
+#[lang = "freeze"]
+trait Freeze {}
+
+impl Copy for i32 {}
+
+#[lang = "div"]
+trait Div<Rhs = Self> {
+    type Output;
+    fn div(self, rhs: Rhs) -> Self::Output;
+}
+
+impl Div for i32 {
+    type Output = i32;
+    fn div(self, rhs: i32) -> i32 {
+        self / rhs
+    }
+}
+
+#[allow(unconditional_panic)]
+pub fn foo() {
+    // This implicitly generates a panic call.
+    let _ = 1 / 0;
+}
+
+//~ MONO_ITEM fn foo
+//~ MONO_ITEM fn <i32 as Div>::div
+//~ MONO_ITEM fn panic

tests/codegen-units/item-collection/instantiation-through-vtable.rs

@@ -0,0 +1,38 @@
+//
+// compile-flags:-Zprint-mono-items=eager -Zinline-in-all-cgus -Zmir-opt-level=0
+
+#![deny(dead_code)]
+#![feature(start)]
+
+trait Trait {
+    fn foo(&self) -> u32;
+    fn bar(&self);
+}
+
+struct Struct<T> {
+    _a: T
+}
+
+impl<T> Trait for Struct<T> {
+    fn foo(&self) -> u32 { 0 }
+    fn bar(&self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    let s1 = Struct { _a: 0u32 };
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u32>> - shim(None) @@ instantiation_through_vtable-cgu.0[Internal]
+    //~ MONO_ITEM fn <Struct<u32> as Trait>::foo
+    //~ MONO_ITEM fn <Struct<u32> as Trait>::bar
+    let _ = &s1 as &Trait;
+
+    let s1 = Struct { _a: 0u64 };
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u64>> - shim(None) @@ instantiation_through_vtable-cgu.0[Internal]
+    //~ MONO_ITEM fn <Struct<u64> as Trait>::foo
+    //~ MONO_ITEM fn <Struct<u64> as Trait>::bar
+    let _ = &s1 as &Trait;
+
+    0
+}

tests/codegen-units/item-collection/items-within-generic-items.rs

@@ -0,0 +1,35 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+fn generic_fn<T>(a: T) -> (T, i32) {
+    //~ MONO_ITEM fn generic_fn::nested_fn
+    fn nested_fn(a: i32) -> i32 {
+        a + 1
+    }
+
+    let x = {
+        //~ MONO_ITEM fn generic_fn::nested_fn
+        fn nested_fn(a: i32) -> i32 {
+            a + 2
+        }
+
+        1 + nested_fn(1)
+    };
+
+    return (a, x + nested_fn(0));
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn generic_fn::<i64>
+    let _ = generic_fn(0i64);
+    //~ MONO_ITEM fn generic_fn::<u16>
+    let _ = generic_fn(0u16);
+    //~ MONO_ITEM fn generic_fn::<i8>
+    let _ = generic_fn(0i8);
+
+    0
+}

tests/codegen-units/item-collection/non-generic-closures.rs

@@ -0,0 +1,60 @@
+// In the current version of the collector that still has to support
+// legacy-codegen, closures do not generate their own MonoItems, so we are
+// ignoring this test until MIR codegen has taken over completely
+// ignore-test
+
+//
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+//~ MONO_ITEM fn non_generic_closures::temporary[0]
+fn temporary() {
+    //~ MONO_ITEM fn non_generic_closures::temporary[0]::{{closure}}[0]
+    (|a: u32| {
+        let _ = a;
+    })(4);
+}
+
+//~ MONO_ITEM fn non_generic_closures::assigned_to_variable_but_not_executed[0]
+fn assigned_to_variable_but_not_executed() {
+    //~ MONO_ITEM fn non_generic_closures::assigned_to_variable_but_not_executed[0]::{{closure}}[0]
+    let _x = |a: i16| {
+        let _ = a + 1;
+    };
+}
+
+//~ MONO_ITEM fn non_generic_closures::assigned_to_variable_executed_directly[0]
+fn assigned_to_variable_executed_indirectly() {
+    //~ MONO_ITEM fn non_generic_closures::assigned_to_variable_executed_directly[0]::{{closure}}[0]
+    let f = |a: i32| {
+        let _ = a + 2;
+    };
+    run_closure(&f);
+}
+
+//~ MONO_ITEM fn non_generic_closures::assigned_to_variable_executed_indirectly[0]
+fn assigned_to_variable_executed_directly() {
+    //~ MONO_ITEM fn non_generic_closures::assigned_to_variable_executed_indirectly[0]::{{closure}}[0]
+    let f = |a: i64| {
+        let _ = a + 3;
+    };
+    f(4);
+}
+
+//~ MONO_ITEM fn non_generic_closures::start[0]
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    temporary();
+    assigned_to_variable_but_not_executed();
+    assigned_to_variable_executed_directly();
+    assigned_to_variable_executed_indirectly();
+
+    0
+}
+
+//~ MONO_ITEM fn non_generic_closures::run_closure[0]
+fn run_closure(f: &Fn(i32)) {
+    f(3);
+}

tests/codegen-units/item-collection/non-generic-drop-glue.rs

@@ -0,0 +1,49 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+
+#![deny(dead_code)]
+#![feature(start)]
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop> - shim(Some(StructWithDrop)) @@ non_generic_drop_glue-cgu.0[Internal]
+struct StructWithDrop {
+    x: i32
+}
+
+impl Drop for StructWithDrop {
+    //~ MONO_ITEM fn <StructWithDrop as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+struct StructNoDrop {
+    x: i32
+}
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<EnumWithDrop> - shim(Some(EnumWithDrop)) @@ non_generic_drop_glue-cgu.0[Internal]
+enum EnumWithDrop {
+    A(i32)
+}
+
+impl Drop for EnumWithDrop {
+    //~ MONO_ITEM fn <EnumWithDrop as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+enum EnumNoDrop {
+    A(i32)
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    let _ = StructWithDrop { x: 0 }.x;
+    let _ = StructNoDrop { x: 0 }.x;
+    let _ = match EnumWithDrop::A(0) {
+        EnumWithDrop::A(x) => x
+    };
+    let _ = match EnumNoDrop::A(0) {
+        EnumNoDrop::A(x) => x
+    };
+
+    0
+}

tests/codegen-units/item-collection/non-generic-functions.rs

@@ -0,0 +1,72 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+//~ MONO_ITEM fn foo
+fn foo() {
+    {
+        //~ MONO_ITEM fn foo::foo
+        fn foo() {}
+        foo();
+    }
+
+    {
+        //~ MONO_ITEM fn foo::foo
+        fn foo() {}
+        foo();
+    }
+}
+
+//~ MONO_ITEM fn bar
+fn bar() {
+    //~ MONO_ITEM fn bar::baz
+    fn baz() {}
+    baz();
+}
+
+struct Struct { _x: i32 }
+
+impl Struct {
+    //~ MONO_ITEM fn Struct::foo
+    fn foo() {
+        {
+            //~ MONO_ITEM fn Struct::foo::foo
+            fn foo() {}
+            foo();
+        }
+
+        {
+            //~ MONO_ITEM fn Struct::foo::foo
+            fn foo() {}
+            foo();
+        }
+    }
+
+    //~ MONO_ITEM fn Struct::bar
+    fn bar(&self) {
+        {
+            //~ MONO_ITEM fn Struct::bar::foo
+            fn foo() {}
+            foo();
+        }
+
+        {
+            //~ MONO_ITEM fn Struct::bar::foo
+            fn foo() {}
+            foo();
+        }
+    }
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    foo();
+    bar();
+    Struct::foo();
+    let x = Struct { _x: 0 };
+    x.bar();
+
+    0
+}

tests/codegen-units/item-collection/overloaded-operators.rs

@@ -0,0 +1,59 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![crate_type="lib"]
+
+use std::ops::{Index, IndexMut, Add, Deref};
+
+pub struct Indexable {
+    data: [u8; 3]
+}
+
+impl Index<usize> for Indexable {
+    type Output = u8;
+
+    //~ MONO_ITEM fn <Indexable as std::ops::Index<usize>>::index
+    fn index(&self, index: usize) -> &Self::Output {
+        if index >= 3 {
+            &self.data[0]
+        } else {
+            &self.data[index]
+        }
+    }
+}
+
+impl IndexMut<usize> for Indexable {
+    //~ MONO_ITEM fn <Indexable as std::ops::IndexMut<usize>>::index_mut
+    fn index_mut(&mut self, index: usize) -> &mut Self::Output {
+        if index >= 3 {
+            &mut self.data[0]
+        } else {
+            &mut self.data[index]
+        }
+    }
+}
+
+
+//~ MONO_ITEM fn <Equatable as std::cmp::PartialEq>::eq
+//~ MONO_ITEM fn <Equatable as std::cmp::PartialEq>::ne
+#[derive(PartialEq)]
+pub struct Equatable(u32);
+
+
+impl Add<u32> for Equatable {
+    type Output = u32;
+
+    //~ MONO_ITEM fn <Equatable as std::ops::Add<u32>>::add
+    fn add(self, rhs: u32) -> u32 {
+        self.0 + rhs
+    }
+}
+
+impl Deref for Equatable {
+    type Target = u32;
+
+    //~ MONO_ITEM fn <Equatable as std::ops::Deref>::deref
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}

tests/codegen-units/item-collection/static-init.rs

@@ -0,0 +1,16 @@
+// compile-flags:-Zprint-mono-items=eager -Zpolymorphize=on
+
+#![feature(start)]
+
+pub static FN : fn() = foo::<i32>;
+
+pub fn foo<T>() { }
+
+//~ MONO_ITEM fn foo::<T>
+//~ MONO_ITEM static FN
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    0
+}

tests/codegen-units/item-collection/statics-and-consts.rs

@@ -0,0 +1,54 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+static STATIC1: i64 = {
+    const STATIC1_CONST1: i64 = 2;
+    1 + CONST1 as i64 + STATIC1_CONST1
+};
+
+const CONST1: i64 = {
+    const CONST1_1: i64 = {
+        const CONST1_1_1: i64 = 2;
+        CONST1_1_1 + 1
+    };
+    1 + CONST1_1 as i64
+};
+
+fn foo() {
+    let _ = {
+        const CONST2: i64 = 0;
+        static STATIC2: i64 = CONST2;
+
+        let x = {
+            const CONST2: i64 = 1;
+            static STATIC2: i64 = CONST2;
+            STATIC2
+        };
+
+        x + STATIC2
+    };
+
+    let _ = {
+        const CONST2: i64 = 0;
+        static STATIC2: i64 = CONST2;
+        STATIC2
+    };
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    foo();
+    let _ = STATIC1;
+
+    0
+}
+
+//~ MONO_ITEM static STATIC1
+
+//~ MONO_ITEM fn foo
+//~ MONO_ITEM static foo::STATIC2
+//~ MONO_ITEM static foo::STATIC2
+//~ MONO_ITEM static foo::STATIC2

tests/codegen-units/item-collection/trait-implementations.rs

@@ -0,0 +1,73 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+pub trait SomeTrait {
+    fn foo(&self);
+    fn bar<T>(&self, x: T);
+}
+
+impl SomeTrait for i64 {
+
+    //~ MONO_ITEM fn <i64 as SomeTrait>::foo
+    fn foo(&self) {}
+
+    fn bar<T>(&self, _: T) {}
+}
+
+impl SomeTrait for i32 {
+
+    //~ MONO_ITEM fn <i32 as SomeTrait>::foo
+    fn foo(&self) {}
+
+    fn bar<T>(&self, _: T) {}
+}
+
+pub trait SomeGenericTrait<T> {
+    fn foo(&self, x: T);
+    fn bar<T2>(&self, x: T, y: T2);
+}
+
+// Concrete impl of generic trait
+impl SomeGenericTrait<u32> for f64 {
+
+    //~ MONO_ITEM fn <f64 as SomeGenericTrait<u32>>::foo
+    fn foo(&self, _: u32) {}
+
+    fn bar<T2>(&self, _: u32, _: T2) {}
+}
+
+// Generic impl of generic trait
+impl<T> SomeGenericTrait<T> for f32 {
+
+    fn foo(&self, _: T) {}
+    fn bar<T2>(&self, _: T, _: T2) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+   //~ MONO_ITEM fn <i32 as SomeTrait>::bar::<char>
+   0i32.bar('x');
+
+   //~ MONO_ITEM fn <f64 as SomeGenericTrait<u32>>::bar::<&str>
+   0f64.bar(0u32, "&str");
+
+   //~ MONO_ITEM fn <f64 as SomeGenericTrait<u32>>::bar::<()>
+   0f64.bar(0u32, ());
+
+   //~ MONO_ITEM fn <f32 as SomeGenericTrait<char>>::foo
+   0f32.foo('x');
+
+   //~ MONO_ITEM fn <f32 as SomeGenericTrait<i64>>::foo
+   0f32.foo(-1i64);
+
+   //~ MONO_ITEM fn <f32 as SomeGenericTrait<u32>>::bar::<()>
+   0f32.bar(0u32, ());
+
+   //~ MONO_ITEM fn <f32 as SomeGenericTrait<&str>>::bar::<&str>
+   0f32.bar("&str", "&str");
+
+   0
+}

tests/codegen-units/item-collection/trait-method-as-argument.rs

@@ -0,0 +1,60 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+
+#![deny(dead_code)]
+#![feature(start)]
+
+trait Trait : Sized {
+    fn foo(self) -> Self { self }
+}
+
+impl Trait for u32 {
+    fn foo(self) -> u32 { self }
+}
+
+impl Trait for char {
+}
+
+fn take_foo_once<T, F: FnOnce(T) -> T>(f: F, arg: T) -> T {
+    (f)(arg)
+}
+
+fn take_foo<T, F: Fn(T) -> T>(f: F, arg: T) -> T {
+    (f)(arg)
+}
+
+fn take_foo_mut<T, F: FnMut(T) -> T>(mut f: F, arg: T) -> T {
+    (f)(arg)
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn take_foo_once::<u32, fn(u32) -> u32 {<u32 as Trait>::foo}>
+    //~ MONO_ITEM fn <u32 as Trait>::foo
+    //~ MONO_ITEM fn <fn(u32) -> u32 {<u32 as Trait>::foo} as std::ops::FnOnce<(u32,)>>::call_once - shim(fn(u32) -> u32 {<u32 as Trait>::foo})
+    take_foo_once(Trait::foo, 0u32);
+
+    //~ MONO_ITEM fn take_foo_once::<char, fn(char) -> char {<char as Trait>::foo}>
+    //~ MONO_ITEM fn <char as Trait>::foo
+    //~ MONO_ITEM fn <fn(char) -> char {<char as Trait>::foo} as std::ops::FnOnce<(char,)>>::call_once - shim(fn(char) -> char {<char as Trait>::foo})
+    take_foo_once(Trait::foo, 'c');
+
+    //~ MONO_ITEM fn take_foo::<u32, fn(u32) -> u32 {<u32 as Trait>::foo}>
+    //~ MONO_ITEM fn <fn(u32) -> u32 {<u32 as Trait>::foo} as std::ops::Fn<(u32,)>>::call - shim(fn(u32) -> u32 {<u32 as Trait>::foo})
+    take_foo(Trait::foo, 0u32);
+
+    //~ MONO_ITEM fn take_foo::<char, fn(char) -> char {<char as Trait>::foo}>
+    //~ MONO_ITEM fn <fn(char) -> char {<char as Trait>::foo} as std::ops::Fn<(char,)>>::call - shim(fn(char) -> char {<char as Trait>::foo})
+    take_foo(Trait::foo, 'c');
+
+    //~ MONO_ITEM fn take_foo_mut::<u32, fn(u32) -> u32 {<u32 as Trait>::foo}>
+    //~ MONO_ITEM fn <fn(u32) -> u32 {<u32 as Trait>::foo} as std::ops::FnMut<(u32,)>>::call_mut - shim(fn(u32) -> u32 {<u32 as Trait>::foo})
+    take_foo_mut(Trait::foo, 0u32);
+
+    //~ MONO_ITEM fn take_foo_mut::<char, fn(char) -> char {<char as Trait>::foo}>
+    //~ MONO_ITEM fn <fn(char) -> char {<char as Trait>::foo} as std::ops::FnMut<(char,)>>::call_mut - shim(fn(char) -> char {<char as Trait>::foo})
+    take_foo_mut(Trait::foo, 'c');
+
+    0
+}

tests/codegen-units/item-collection/trait-method-default-impl.rs

@@ -0,0 +1,61 @@
+// compile-flags:-Zprint-mono-items=eager -Zpolymorphize=on
+
+#![deny(dead_code)]
+#![feature(start)]
+
+trait SomeTrait {
+    fn foo(&self) { }
+    fn bar<T>(&self, x: T) -> T { x }
+}
+
+impl SomeTrait for i8 {
+    // take the default implementations
+
+    // For the non-generic foo(), we should generate a codegen-item even if it
+    // is not called anywhere
+    //~ MONO_ITEM fn <i8 as SomeTrait>::foo
+}
+
+trait SomeGenericTrait<T1> {
+    fn foo(&self) { }
+    fn bar<T2>(&self, x: T1, y: T2) {}
+}
+
+// Non-generic impl of generic trait
+impl SomeGenericTrait<u64> for i32 {
+    // take the default implementations
+
+    // For the non-generic foo(), we should generate a codegen-item even if it
+    // is not called anywhere
+    //~ MONO_ITEM fn <i32 as SomeGenericTrait<T1>>::foo
+}
+
+// Non-generic impl of generic trait
+impl<T1> SomeGenericTrait<T1> for u32 {
+    // take the default implementations
+    // since nothing is monomorphic here, nothing should be generated unless used somewhere.
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn <i8 as SomeTrait>::bar::<char>
+    let _ = 1i8.bar('c');
+
+    //~ MONO_ITEM fn <i8 as SomeTrait>::bar::<&str>
+    let _ = 2i8.bar("&str");
+
+    //~ MONO_ITEM fn <i32 as SomeGenericTrait<u64>>::bar::<char>
+    0i32.bar(0u64, 'c');
+
+    //~ MONO_ITEM fn <i32 as SomeGenericTrait<u64>>::bar::<&str>
+    0i32.bar(0u64, "&str");
+
+    //~ MONO_ITEM fn <u32 as SomeGenericTrait<i8>>::bar::<&[char; 1]>
+    0u32.bar(0i8, &['c']);
+
+    //~ MONO_ITEM fn <u32 as SomeGenericTrait<i16>>::bar::<()>
+    0u32.bar(0i16, ());
+
+    0
+}

tests/codegen-units/item-collection/transitive-drop-glue.rs

@@ -0,0 +1,46 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+
+#![deny(dead_code)]
+#![feature(start)]
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Root> - shim(Some(Root)) @@ transitive_drop_glue-cgu.0[Internal]
+struct Root(#[allow(unused_tuple_struct_fields)] Intermediate);
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Intermediate> - shim(Some(Intermediate)) @@ transitive_drop_glue-cgu.0[Internal]
+struct Intermediate(#[allow(unused_tuple_struct_fields)] Leaf);
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Leaf> - shim(Some(Leaf)) @@ transitive_drop_glue-cgu.0[Internal]
+struct Leaf;
+
+impl Drop for Leaf {
+    //~ MONO_ITEM fn <Leaf as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+struct RootGen<T>(#[allow(unused_tuple_struct_fields)] IntermediateGen<T>);
+struct IntermediateGen<T>(#[allow(unused_tuple_struct_fields)] LeafGen<T>);
+struct LeafGen<T>(#[allow(unused_tuple_struct_fields)] T);
+
+impl<T> Drop for LeafGen<T> {
+    fn drop(&mut self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    let _ = Root(Intermediate(Leaf));
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<RootGen<u32>> - shim(Some(RootGen<u32>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<IntermediateGen<u32>> - shim(Some(IntermediateGen<u32>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<LeafGen<u32>> - shim(Some(LeafGen<u32>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <LeafGen<u32> as std::ops::Drop>::drop
+    let _ = RootGen(IntermediateGen(LeafGen(0u32)));
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<RootGen<i16>> - shim(Some(RootGen<i16>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<IntermediateGen<i16>> - shim(Some(IntermediateGen<i16>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<LeafGen<i16>> - shim(Some(LeafGen<i16>)) @@ transitive_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn <LeafGen<i16> as std::ops::Drop>::drop
+    let _ = RootGen(IntermediateGen(LeafGen(0i16)));
+
+    0
+}

tests/codegen-units/item-collection/tuple-drop-glue.rs

@@ -0,0 +1,27 @@
+//
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+
+#![deny(dead_code)]
+#![feature(start)]
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Dropped> - shim(Some(Dropped)) @@ tuple_drop_glue-cgu.0[Internal]
+struct Dropped;
+
+impl Drop for Dropped {
+    //~ MONO_ITEM fn <Dropped as std::ops::Drop>::drop
+    fn drop(&mut self) {}
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<(u32, Dropped)> - shim(Some((u32, Dropped))) @@ tuple_drop_glue-cgu.0[Internal]
+    let x = (0u32, Dropped);
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<(i16, (Dropped, bool))> - shim(Some((i16, (Dropped, bool)))) @@ tuple_drop_glue-cgu.0[Internal]
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<(Dropped, bool)> - shim(Some((Dropped, bool)))  @@ tuple_drop_glue-cgu.0[Internal]
+    let x = (0i16, (Dropped, true));
+
+    0
+}

tests/codegen-units/item-collection/unreferenced-const-fn.rs

@@ -0,0 +1,9 @@
+// compile-flags:-Zprint-mono-items=lazy
+
+#![deny(dead_code)]
+#![crate_type = "rlib"]
+
+//~ MONO_ITEM fn foo @@ unreferenced_const_fn-cgu.0[External]
+pub const fn foo(x: u32) -> u32 {
+    x + 0xf00
+}

tests/codegen-units/item-collection/unreferenced-inline-function.rs

@@ -0,0 +1,11 @@
+// compile-flags:-Zprint-mono-items=lazy
+
+// N.B., we do not expect *any* monomorphization to be generated here.
+
+#![deny(dead_code)]
+#![crate_type = "rlib"]
+
+#[inline]
+pub fn foo() -> bool {
+    [1, 2] == [3, 4]
+}

tests/codegen-units/item-collection/unsizing.rs

@@ -0,0 +1,79 @@
+// compile-flags:-Zprint-mono-items=eager
+// compile-flags:-Zinline-in-all-cgus
+// compile-flags:-Zmir-opt-level=0
+
+#![deny(dead_code)]
+#![feature(coerce_unsized)]
+#![feature(unsize)]
+#![feature(start)]
+
+use std::marker::Unsize;
+use std::ops::CoerceUnsized;
+
+trait Trait {
+    fn foo(&self);
+}
+
+// Simple Case
+impl Trait for bool {
+    fn foo(&self) {}
+}
+
+impl Trait for char {
+    fn foo(&self) {}
+}
+
+// Struct Field Case
+struct Struct<T: ?Sized> {
+    _a: u32,
+    _b: i32,
+    _c: T
+}
+
+impl Trait for f64 {
+    fn foo(&self) {}
+}
+
+// Custom Coercion Case
+impl Trait for u32 {
+    fn foo(&self) {}
+}
+
+#[derive(Clone, Copy)]
+struct Wrapper<T: ?Sized>(#[allow(unused_tuple_struct_fields)] *const T);
+
+impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Wrapper<U>> for Wrapper<T> {}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    // simple case
+    let bool_sized = &true;
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<bool> - shim(None) @@ unsizing-cgu.0[Internal]
+    //~ MONO_ITEM fn <bool as Trait>::foo
+    let _bool_unsized = bool_sized as &Trait;
+
+    let char_sized = &'a';
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<char> - shim(None) @@ unsizing-cgu.0[Internal]
+    //~ MONO_ITEM fn <char as Trait>::foo
+    let _char_unsized = char_sized as &Trait;
+
+    // struct field
+    let struct_sized = &Struct {
+        _a: 1,
+        _b: 2,
+        _c: 3.0f64
+    };
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<f64> - shim(None) @@ unsizing-cgu.0[Internal]
+    //~ MONO_ITEM fn <f64 as Trait>::foo
+    let _struct_unsized = struct_sized as &Struct<Trait>;
+
+    // custom coercion
+    let wrapper_sized = Wrapper(&0u32);
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<u32> - shim(None) @@ unsizing-cgu.0[Internal]
+    //~ MONO_ITEM fn <u32 as Trait>::foo
+    let _wrapper_sized = wrapper_sized as Wrapper<Trait>;
+
+    0
+}

tests/codegen-units/item-collection/unused-traits-and-generics.rs

@@ -0,0 +1,77 @@
+// compile-flags:-Zprint-mono-items=eager
+
+#![crate_type="lib"]
+#![deny(dead_code)]
+
+// This test asserts that no codegen items are generated for generic items that
+// are never instantiated in the local crate.
+
+pub trait Trait {
+    fn foo() {}
+    fn bar(&self) {}
+}
+
+pub fn foo<T: Copy>(x: T) -> (T, T) {
+    (x, x)
+}
+
+pub struct Struct<T> {
+    x: T
+}
+
+impl<T> Struct<T> {
+    pub fn foo(self) -> T {
+        self.x
+    }
+
+    pub fn bar() {}
+}
+
+pub enum Enum<T> {
+    A(T),
+    B { x: T }
+}
+
+impl<T> Enum<T> {
+    pub fn foo(self) -> T {
+        match self {
+            Enum::A(x) => x,
+            Enum::B { x } => x,
+        }
+    }
+
+    pub fn bar() {}
+}
+
+pub struct TupleStruct<T>(T);
+
+impl<T> TupleStruct<T> {
+    pub fn foo(self) -> T {
+        self.0
+    }
+
+    pub fn bar() {}
+}
+
+pub type Pair<T> = (T, T);
+
+pub struct NonGeneric {
+    x: i32
+}
+
+impl NonGeneric {
+    pub fn foo(self) -> i32 {
+        self.x
+    }
+
+    pub fn generic_foo<T>(&self, x: T) -> (T, i32) {
+        (x, self.x)
+    }
+
+    pub fn generic_bar<T: Copy>(x: T) -> (T, T) {
+        (x, x)
+    }
+}
+
+// Only the non-generic methods should be instantiated:
+//~ MONO_ITEM fn NonGeneric::foo

tests/codegen-units/partitioning/auxiliary/cgu_explicit_inlining.rs

@@ -0,0 +1,10 @@
+#![crate_type = "lib"]
+
+#[inline]
+pub fn inlined() {}
+
+#[inline(always)]
+pub fn always_inlined() {}
+
+#[inline(never)]
+pub fn never_inlined() {}

tests/codegen-units/partitioning/auxiliary/cgu_extern_drop_glue.rs

@@ -0,0 +1,7 @@
+#![crate_type = "lib"]
+
+pub struct Struct(pub u32);
+
+impl Drop for Struct {
+    fn drop(&mut self) {}
+}

tests/codegen-units/partitioning/auxiliary/cgu_generic_function.rs

@@ -0,0 +1,26 @@
+#![crate_type = "lib"]
+
+struct Struct(u32);
+
+#[inline(never)]
+pub fn foo<T>(x: T) -> (T, u32, i8) {
+    let (x, Struct(y)) = bar(x);
+    (x, y, 2)
+}
+
+#[inline(never)]
+fn bar<T>(x: T) -> (T, Struct) {
+    let _ = not_exported_and_not_generic(0);
+    (x, Struct(1))
+}
+
+// These should not contribute to the codegen items of other crates.
+#[inline(never)]
+pub fn exported_but_not_generic(x: i32) -> i64 {
+    x as i64
+}
+
+#[inline(never)]
+fn not_exported_and_not_generic(x: u32) -> u64 {
+    x as u64
+}

tests/codegen-units/partitioning/auxiliary/shared_generics_aux.rs

@@ -0,0 +1,26 @@
+// NOTE: We always compile this test with -Copt-level=0 because higher opt-levels
+//       prevent drop-glue from participating in share-generics.
+// compile-flags:-Zshare-generics=yes -Copt-level=0
+// no-prefer-dynamic
+
+#![crate_type="rlib"]
+
+pub fn generic_fn<T>(x: T, y: T) -> (T, T) {
+    (x, y)
+}
+
+pub fn use_generic_fn_f32() -> (f32, f32) {
+    // This line causes drop glue for Foo to be instantiated. We want to make
+    // sure that this crate exports an instance to be re-used by share-generics.
+    let _ = Foo(0);
+
+    generic_fn(0.0f32, 1.0f32)
+}
+
+pub struct Foo(pub u32);
+
+impl Drop for Foo {
+    fn drop(&mut self) {
+        println!("foo");
+    }
+}

tests/codegen-units/partitioning/extern-drop-glue.rs

@@ -0,0 +1,36 @@
+//
+
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// We specify opt-level=0 because `drop_in_place` is `Internal` when optimizing
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus -Copt-level=0
+
+#![allow(dead_code)]
+#![crate_type = "rlib"]
+
+// aux-build:cgu_extern_drop_glue.rs
+extern crate cgu_extern_drop_glue;
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<cgu_extern_drop_glue::Struct> - shim(Some(cgu_extern_drop_glue::Struct)) @@ extern_drop_glue-fallback.cgu[External]
+
+struct LocalStruct(cgu_extern_drop_glue::Struct);
+
+//~ MONO_ITEM fn user @@ extern_drop_glue[External]
+pub fn user() {
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<LocalStruct> - shim(Some(LocalStruct)) @@ extern_drop_glue-fallback.cgu[External]
+    let _ = LocalStruct(cgu_extern_drop_glue::Struct(0));
+}
+
+pub mod mod1 {
+    use cgu_extern_drop_glue;
+
+    struct LocalStruct(cgu_extern_drop_glue::Struct);
+
+    //~ MONO_ITEM fn mod1::user @@ extern_drop_glue-mod1[External]
+    pub fn user() {
+        //~ MONO_ITEM fn std::ptr::drop_in_place::<mod1::LocalStruct> - shim(Some(mod1::LocalStruct)) @@ extern_drop_glue-fallback.cgu[External]
+        let _ = LocalStruct(cgu_extern_drop_glue::Struct(0));
+    }
+}

tests/codegen-units/partitioning/extern-generic.rs

@@ -0,0 +1,53 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=eager -Zshare-generics=y
+
+#![allow(dead_code)]
+#![crate_type="lib"]
+
+// aux-build:cgu_generic_function.rs
+extern crate cgu_generic_function;
+
+//~ MONO_ITEM fn user @@ extern_generic[Internal]
+fn user() {
+    let _ = cgu_generic_function::foo("abc");
+}
+
+mod mod1 {
+    use cgu_generic_function;
+
+    //~ MONO_ITEM fn mod1::user @@ extern_generic-mod1[Internal]
+    fn user() {
+        let _ = cgu_generic_function::foo("abc");
+    }
+
+    mod mod1 {
+        use cgu_generic_function;
+
+        //~ MONO_ITEM fn mod1::mod1::user @@ extern_generic-mod1-mod1[Internal]
+        fn user() {
+            let _ = cgu_generic_function::foo("abc");
+        }
+    }
+}
+
+mod mod2 {
+    use cgu_generic_function;
+
+    //~ MONO_ITEM fn mod2::user @@ extern_generic-mod2[Internal]
+    fn user() {
+        let _ = cgu_generic_function::foo("abc");
+    }
+}
+
+mod mod3 {
+    //~ MONO_ITEM fn mod3::non_user @@ extern_generic-mod3[Internal]
+    fn non_user() {}
+}
+
+// Make sure the two generic functions from the extern crate get instantiated
+// once for the current crate
+//~ MONO_ITEM fn cgu_generic_function::foo::<&str> @@ cgu_generic_function-in-extern_generic.volatile[External]
+//~ MONO_ITEM fn cgu_generic_function::bar::<&str> @@ cgu_generic_function-in-extern_generic.volatile[External]

tests/codegen-units/partitioning/incremental-merging.rs

@@ -0,0 +1,42 @@
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Ccodegen-units=3
+
+#![crate_type = "rlib"]
+
+// This test makes sure that merging of CGUs works together with incremental
+// compilation but at the same time does not modify names of CGUs that were not
+// affected by merging.
+//
+// We expect CGUs `aaa` and `bbb` to be merged (because they are the smallest),
+// while `ccc` and `ddd` are supposed to stay untouched.
+
+pub mod aaa {
+    //~ MONO_ITEM fn aaa::foo @@ incremental_merging-aaa--incremental_merging-bbb[External]
+    pub fn foo(a: u64) -> u64 {
+        a + 1
+    }
+}
+
+pub mod bbb {
+    //~ MONO_ITEM fn bbb::foo @@ incremental_merging-aaa--incremental_merging-bbb[External]
+    pub fn foo(a: u64, b: u64) -> u64 {
+        a + b + 1
+    }
+}
+
+pub mod ccc {
+    //~ MONO_ITEM fn ccc::foo @@ incremental_merging-ccc[External]
+    pub fn foo(a: u64, b: u64, c: u64) -> u64 {
+        a + b + c + 1
+    }
+}
+
+pub mod ddd {
+    //~ MONO_ITEM fn ddd::foo @@ incremental_merging-ddd[External]
+    pub fn foo(a: u64, b: u64, c: u64, d: u64) -> u64 {
+        a + b + c + d + 1
+    }
+}

tests/codegen-units/partitioning/inlining-from-extern-crate.rs

@@ -0,0 +1,53 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus
+
+#![crate_type="lib"]
+
+// aux-build:cgu_explicit_inlining.rs
+extern crate cgu_explicit_inlining;
+
+// This test makes sure that items inlined from external crates are privately
+// instantiated in every codegen unit they are used in.
+
+//~ MONO_ITEM fn cgu_explicit_inlining::inlined @@ inlining_from_extern_crate[Internal] inlining_from_extern_crate-mod1[Internal]
+//~ MONO_ITEM fn cgu_explicit_inlining::always_inlined @@ inlining_from_extern_crate[Internal] inlining_from_extern_crate-mod2[Internal]
+
+//~ MONO_ITEM fn user @@ inlining_from_extern_crate[External]
+pub fn user()
+{
+    cgu_explicit_inlining::inlined();
+    cgu_explicit_inlining::always_inlined();
+
+    // does not generate a monomorphization in this crate
+    cgu_explicit_inlining::never_inlined();
+}
+
+pub mod mod1 {
+    use cgu_explicit_inlining;
+
+    //~ MONO_ITEM fn mod1::user @@ inlining_from_extern_crate-mod1[External]
+    pub fn user()
+    {
+        cgu_explicit_inlining::inlined();
+
+        // does not generate a monomorphization in this crate
+        cgu_explicit_inlining::never_inlined();
+    }
+}
+
+pub mod mod2 {
+    use cgu_explicit_inlining;
+
+    //~ MONO_ITEM fn mod2::user @@ inlining_from_extern_crate-mod2[External]
+    pub fn user()
+    {
+        cgu_explicit_inlining::always_inlined();
+
+        // does not generate a monomorphization in this crate
+        cgu_explicit_inlining::never_inlined();
+    }
+}

tests/codegen-units/partitioning/local-drop-glue.rs

@@ -0,0 +1,46 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// We specify opt-level=0 because `drop_in_place` is `Internal` when optimizing
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus -Copt-level=0
+
+#![allow(dead_code)]
+#![crate_type = "rlib"]
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Struct> - shim(Some(Struct)) @@ local_drop_glue-fallback.cgu[External]
+struct Struct {
+    _a: u32,
+}
+
+impl Drop for Struct {
+    //~ MONO_ITEM fn <Struct as std::ops::Drop>::drop @@ local_drop_glue-fallback.cgu[External]
+    fn drop(&mut self) {}
+}
+
+//~ MONO_ITEM fn std::ptr::drop_in_place::<Outer> - shim(Some(Outer)) @@ local_drop_glue-fallback.cgu[External]
+struct Outer {
+    _a: Struct,
+}
+
+//~ MONO_ITEM fn user @@ local_drop_glue[External]
+pub fn user() {
+    let _ = Outer { _a: Struct { _a: 0 } };
+}
+
+pub mod mod1 {
+    use super::Struct;
+
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<mod1::Struct2> - shim(Some(mod1::Struct2)) @@ local_drop_glue-fallback.cgu[External]
+    struct Struct2 {
+        _a: Struct,
+        //~ MONO_ITEM fn std::ptr::drop_in_place::<(u32, Struct)> - shim(Some((u32, Struct))) @@ local_drop_glue-fallback.cgu[Internal]
+        _b: (u32, Struct),
+    }
+
+    //~ MONO_ITEM fn mod1::user @@ local_drop_glue-mod1[External]
+    pub fn user() {
+        let _ = Struct2 { _a: Struct { _a: 0 }, _b: (0, Struct { _a: 0 }) };
+    }
+}

tests/codegen-units/partitioning/local-generic.rs

@@ -0,0 +1,45 @@
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=eager
+
+#![allow(dead_code)]
+#![crate_type="lib"]
+
+//~ MONO_ITEM fn generic::<u32> @@ local_generic.volatile[External]
+//~ MONO_ITEM fn generic::<u64> @@ local_generic.volatile[External]
+//~ MONO_ITEM fn generic::<char> @@ local_generic.volatile[External]
+//~ MONO_ITEM fn generic::<&str> @@ local_generic.volatile[External]
+pub fn generic<T>(x: T) -> T { x }
+
+//~ MONO_ITEM fn user @@ local_generic[Internal]
+fn user() {
+    let _ = generic(0u32);
+}
+
+mod mod1 {
+    pub use super::generic;
+
+    //~ MONO_ITEM fn mod1::user @@ local_generic-mod1[Internal]
+    fn user() {
+        let _ = generic(0u64);
+    }
+
+    mod mod1 {
+        use super::generic;
+
+        //~ MONO_ITEM fn mod1::mod1::user @@ local_generic-mod1-mod1[Internal]
+        fn user() {
+            let _ = generic('c');
+        }
+    }
+}
+
+mod mod2 {
+    use super::generic;
+
+    //~ MONO_ITEM fn mod2::user @@ local_generic-mod2[Internal]
+    fn user() {
+        let _ = generic("abc");
+    }
+}

tests/codegen-units/partitioning/local-inlining-but-not-all.rs

@@ -0,0 +1,45 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus=no
+
+#![allow(dead_code)]
+#![crate_type="lib"]
+
+mod inline {
+
+    //~ MONO_ITEM fn inline::inlined_function @@ local_inlining_but_not_all-inline[External]
+    #[inline]
+    pub fn inlined_function()
+    {
+
+    }
+}
+
+pub mod user1 {
+    use super::inline;
+
+    //~ MONO_ITEM fn user1::foo @@ local_inlining_but_not_all-user1[External]
+    pub fn foo() {
+        inline::inlined_function();
+    }
+}
+
+pub mod user2 {
+    use super::inline;
+
+    //~ MONO_ITEM fn user2::bar @@ local_inlining_but_not_all-user2[External]
+    pub fn bar() {
+        inline::inlined_function();
+    }
+}
+
+pub mod non_user {
+
+    //~ MONO_ITEM fn non_user::baz @@ local_inlining_but_not_all-non_user[External]
+    pub fn baz() {
+
+    }
+}

tests/codegen-units/partitioning/local-inlining.rs

@@ -0,0 +1,46 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus
+
+#![allow(dead_code)]
+#![crate_type="lib"]
+
+mod inline {
+
+    // Important: This function should show up in all codegen units where it is inlined
+    //~ MONO_ITEM fn inline::inlined_function @@ local_inlining-user1[Internal] local_inlining-user2[Internal]
+    #[inline(always)]
+    pub fn inlined_function()
+    {
+
+    }
+}
+
+pub mod user1 {
+    use super::inline;
+
+    //~ MONO_ITEM fn user1::foo @@ local_inlining-user1[External]
+    pub fn foo() {
+        inline::inlined_function();
+    }
+}
+
+pub mod user2 {
+    use super::inline;
+
+    //~ MONO_ITEM fn user2::bar @@ local_inlining-user2[External]
+    pub fn bar() {
+        inline::inlined_function();
+    }
+}
+
+pub mod non_user {
+
+    //~ MONO_ITEM fn non_user::baz @@ local_inlining-non_user[External]
+    pub fn baz() {
+
+    }
+}

tests/codegen-units/partitioning/local-transitive-inlining.rs

@@ -0,0 +1,46 @@
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus
+
+#![allow(dead_code)]
+#![crate_type="rlib"]
+
+mod inline {
+
+    //~ MONO_ITEM fn inline::inlined_function @@ local_transitive_inlining-indirect_user[Internal]
+    #[inline(always)]
+    pub fn inlined_function()
+    {
+
+    }
+}
+
+mod direct_user {
+    use super::inline;
+
+    //~ MONO_ITEM fn direct_user::foo @@ local_transitive_inlining-indirect_user[Internal]
+    #[inline(always)]
+    pub fn foo() {
+        inline::inlined_function();
+    }
+}
+
+pub mod indirect_user {
+    use super::direct_user;
+
+    //~ MONO_ITEM fn indirect_user::bar @@ local_transitive_inlining-indirect_user[External]
+    pub fn bar() {
+        direct_user::foo();
+    }
+}
+
+pub mod non_user {
+
+    //~ MONO_ITEM fn non_user::baz @@ local_transitive_inlining-non_user[External]
+    pub fn baz() {
+
+    }
+}

tests/codegen-units/partitioning/methods-are-with-self-type.rs

@@ -0,0 +1,79 @@
+// Currently, all generic functions are instantiated in each codegen unit that
+// uses them, even those not marked with #[inline], so this test does not make
+// much sense at the moment.
+// ignore-test
+
+//
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+
+#![allow(dead_code)]
+#![feature(start)]
+
+struct SomeType;
+
+struct SomeGenericType<T1, T2>(T1, T2);
+
+mod mod1 {
+    use super::{SomeType, SomeGenericType};
+
+    // Even though the impl is in `mod1`, the methods should end up in the
+    // parent module, since that is where their self-type is.
+    impl SomeType {
+        //~ MONO_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[0]::method[0] @@ methods_are_with_self_type[External]
+        fn method(&self) {}
+
+        //~ MONO_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[0]::associated_fn[0] @@ methods_are_with_self_type[External]
+        fn associated_fn() {}
+    }
+
+    impl<T1, T2> SomeGenericType<T1, T2> {
+        pub fn method(&self) {}
+        pub fn associated_fn(_: T1, _: T2) {}
+    }
+}
+
+trait Trait {
+    fn foo(&self);
+    fn default(&self) {}
+}
+
+// We provide an implementation of `Trait` for all types. The corresponding
+// monomorphizations should end up in whichever module the concrete `T` is.
+impl<T> Trait for T
+{
+    fn foo(&self) {}
+}
+
+mod type1 {
+    pub struct Struct;
+}
+
+mod type2 {
+    pub struct Struct;
+}
+
+//~ MONO_ITEM fn methods_are_with_self_type::start[0]
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::method[0]<u32, u64> @@ methods_are_with_self_type.volatile[WeakODR]
+    SomeGenericType(0u32, 0u64).method();
+    //~ MONO_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::associated_fn[0]<char, &str> @@ methods_are_with_self_type.volatile[WeakODR]
+    SomeGenericType::associated_fn('c', "&str");
+
+    //~ MONO_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR]
+    type1::Struct.foo();
+    //~ MONO_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR]
+    type2::Struct.foo();
+
+    //~ MONO_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR]
+    type1::Struct.default();
+    //~ MONO_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR]
+    type2::Struct.default();
+
+    0
+}
+
+//~ MONO_ITEM drop-glue i8

tests/codegen-units/partitioning/regular-modules.rs

@@ -0,0 +1,72 @@
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=eager
+
+#![allow(dead_code)]
+#![crate_type="lib"]
+
+//~ MONO_ITEM fn foo @@ regular_modules[Internal]
+fn foo() {}
+
+//~ MONO_ITEM fn bar @@ regular_modules[Internal]
+fn bar() {}
+
+//~ MONO_ITEM static BAZ @@ regular_modules[Internal]
+static BAZ: u64 = 0;
+
+mod mod1 {
+
+    //~ MONO_ITEM fn mod1::foo @@ regular_modules-mod1[Internal]
+    fn foo() {}
+    //~ MONO_ITEM fn mod1::bar @@ regular_modules-mod1[Internal]
+    fn bar() {}
+    //~ MONO_ITEM static mod1::BAZ @@ regular_modules-mod1[Internal]
+    static BAZ: u64 = 0;
+
+    mod mod1 {
+        //~ MONO_ITEM fn mod1::mod1::foo @@ regular_modules-mod1-mod1[Internal]
+        fn foo() {}
+        //~ MONO_ITEM fn mod1::mod1::bar @@ regular_modules-mod1-mod1[Internal]
+        fn bar() {}
+        //~ MONO_ITEM static mod1::mod1::BAZ @@ regular_modules-mod1-mod1[Internal]
+        static BAZ: u64 = 0;
+    }
+
+    mod mod2 {
+        //~ MONO_ITEM fn mod1::mod2::foo @@ regular_modules-mod1-mod2[Internal]
+        fn foo() {}
+        //~ MONO_ITEM fn mod1::mod2::bar @@ regular_modules-mod1-mod2[Internal]
+        fn bar() {}
+        //~ MONO_ITEM static mod1::mod2::BAZ @@ regular_modules-mod1-mod2[Internal]
+        static BAZ: u64 = 0;
+    }
+}
+
+mod mod2 {
+
+    //~ MONO_ITEM fn mod2::foo @@ regular_modules-mod2[Internal]
+    fn foo() {}
+    //~ MONO_ITEM fn mod2::bar @@ regular_modules-mod2[Internal]
+    fn bar() {}
+    //~ MONO_ITEM static mod2::BAZ @@ regular_modules-mod2[Internal]
+    static BAZ: u64 = 0;
+
+    mod mod1 {
+        //~ MONO_ITEM fn mod2::mod1::foo @@ regular_modules-mod2-mod1[Internal]
+        fn foo() {}
+        //~ MONO_ITEM fn mod2::mod1::bar @@ regular_modules-mod2-mod1[Internal]
+        fn bar() {}
+        //~ MONO_ITEM static mod2::mod1::BAZ @@ regular_modules-mod2-mod1[Internal]
+        static BAZ: u64 = 0;
+    }
+
+    mod mod2 {
+        //~ MONO_ITEM fn mod2::mod2::foo @@ regular_modules-mod2-mod2[Internal]
+        fn foo() {}
+        //~ MONO_ITEM fn mod2::mod2::bar @@ regular_modules-mod2-mod2[Internal]
+        fn bar() {}
+        //~ MONO_ITEM static mod2::mod2::BAZ @@ regular_modules-mod2-mod2[Internal]
+        static BAZ: u64 = 0;
+    }
+}

tests/codegen-units/partitioning/shared-generics.rs

@@ -0,0 +1,28 @@
+//
+// no-prefer-dynamic
+// NOTE: We always compile this test with -Copt-level=0 because higher opt-levels
+//       prevent drop-glue from participating in share-generics.
+// incremental
+// compile-flags:-Zprint-mono-items=eager -Zshare-generics=yes -Copt-level=0
+
+#![crate_type="rlib"]
+
+// aux-build:shared_generics_aux.rs
+extern crate shared_generics_aux;
+
+//~ MONO_ITEM fn foo
+pub fn foo() {
+
+    //~ MONO_ITEM fn shared_generics_aux::generic_fn::<u16> @@ shared_generics_aux-in-shared_generics.volatile[External]
+    let _ = shared_generics_aux::generic_fn(0u16, 1u16);
+
+    // This should not generate a monomorphization because it's already
+    // available in `shared_generics_aux`.
+    let _ = shared_generics_aux::generic_fn(0.0f32, 3.0f32);
+
+    // The following line will drop an instance of `Foo`, generating a call to
+    // Foo's drop-glue function. However, share-generics should take care of
+    // reusing the drop-glue from the upstream crate, so we do not expect a
+    // mono item for the drop-glue
+    let _ = shared_generics_aux::Foo(1);
+}

tests/codegen-units/partitioning/statics.rs

@@ -0,0 +1,38 @@
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+
+#![crate_type="rlib"]
+
+//~ MONO_ITEM static FOO @@ statics[Internal]
+static FOO: u32 = 0;
+
+//~ MONO_ITEM static BAR @@ statics[Internal]
+static BAR: u32 = 0;
+
+//~ MONO_ITEM fn function @@ statics[External]
+pub fn function() {
+    //~ MONO_ITEM static function::FOO @@ statics[Internal]
+    static FOO: u32 = 0;
+
+    //~ MONO_ITEM static function::BAR @@ statics[Internal]
+    static BAR: u32 = 0;
+}
+
+pub mod mod1 {
+    //~ MONO_ITEM static mod1::FOO @@ statics-mod1[Internal]
+    static FOO: u32 = 0;
+
+    //~ MONO_ITEM static mod1::BAR @@ statics-mod1[Internal]
+    static BAR: u32 = 0;
+
+    //~ MONO_ITEM fn mod1::function @@ statics-mod1[External]
+    pub fn function() {
+        //~ MONO_ITEM static mod1::function::FOO @@ statics-mod1[Internal]
+        static FOO: u32 = 0;
+
+        //~ MONO_ITEM static mod1::function::BAR @@ statics-mod1[Internal]
+        static BAR: u32 = 0;
+    }
+}

tests/codegen-units/partitioning/vtable-through-const.rs

@@ -0,0 +1,94 @@
+//
+
+// We specify incremental here because we want to test the partitioning for
+// incremental compilation
+// incremental
+// compile-flags:-Zprint-mono-items=lazy
+// compile-flags:-Zinline-in-all-cgus
+
+// This test case makes sure, that references made through constants are
+// recorded properly in the InliningMap.
+
+#![feature(start)]
+
+mod mod1 {
+    pub trait Trait1 {
+        fn do_something(&self) {}
+        fn do_something_else(&self) {}
+    }
+
+    impl Trait1 for u32 {}
+
+    pub trait Trait1Gen<T> {
+        fn do_something(&self, x: T) -> T;
+        fn do_something_else(&self, x: T) -> T;
+    }
+
+    impl<T> Trait1Gen<T> for u32 {
+        fn do_something(&self, x: T) -> T { x }
+        fn do_something_else(&self, x: T) -> T { x }
+    }
+
+    //~ MONO_ITEM fn mod1::id::<i64> @@ vtable_through_const-mod1.volatile[Internal]
+    fn id<T>(x: T) -> T { x }
+
+    // These are referenced, so they produce mono-items (see start())
+    pub const TRAIT1_REF: &'static Trait1 = &0u32 as &Trait1;
+    pub const TRAIT1_GEN_REF: &'static Trait1Gen<u8> = &0u32 as &Trait1Gen<u8>;
+    pub const ID_CHAR: fn(char) -> char = id::<char>;
+
+
+
+    pub trait Trait2 {
+        fn do_something(&self) {}
+        fn do_something_else(&self) {}
+    }
+
+    //~ MONO_ITEM fn <u32 as mod1::Trait2>::do_something @@ vtable_through_const-mod1.volatile[Internal]
+    //~ MONO_ITEM fn <u32 as mod1::Trait2>::do_something_else @@ vtable_through_const-mod1.volatile[Internal]
+    impl Trait2 for u32 {}
+
+    pub trait Trait2Gen<T> {
+        fn do_something(&self, x: T) -> T;
+        fn do_something_else(&self, x: T) -> T;
+    }
+
+    impl<T> Trait2Gen<T> for u32 {
+        fn do_something(&self, x: T) -> T { x }
+        fn do_something_else(&self, x: T) -> T { x }
+    }
+
+    // These are not referenced, so they do not produce mono-items
+    pub const TRAIT2_REF: &'static Trait2 = &0u32 as &Trait2;
+    pub const TRAIT2_GEN_REF: &'static Trait2Gen<u8> = &0u32 as &Trait2Gen<u8>;
+    pub const ID_I64: fn(i64) -> i64 = id::<i64>;
+}
+
+//~ MONO_ITEM fn start
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn std::ptr::drop_in_place::<u32> - shim(None) @@ vtable_through_const[Internal]
+
+    // Since Trait1::do_something() is instantiated via its default implementation,
+    // it is considered a generic and is instantiated here only because it is
+    // referenced in this module.
+    //~ MONO_ITEM fn <u32 as mod1::Trait1>::do_something_else @@ vtable_through_const-mod1.volatile[External]
+
+    // Although it is never used, Trait1::do_something_else() has to be
+    // instantiated locally here too, otherwise the <&u32 as &Trait1> vtable
+    // could not be fully constructed.
+    //~ MONO_ITEM fn <u32 as mod1::Trait1>::do_something @@ vtable_through_const-mod1.volatile[External]
+    mod1::TRAIT1_REF.do_something();
+
+    // Same as above
+    //~ MONO_ITEM fn <u32 as mod1::Trait1Gen<u8>>::do_something @@ vtable_through_const-mod1.volatile[External]
+    //~ MONO_ITEM fn <u32 as mod1::Trait1Gen<u8>>::do_something_else @@ vtable_through_const-mod1.volatile[External]
+    //~ MONO_ITEM fn <u32 as mod1::Trait2Gen<u8>>::do_something @@ vtable_through_const-mod1.volatile[Internal]
+    //~ MONO_ITEM fn <u32 as mod1::Trait2Gen<u8>>::do_something_else @@ vtable_through_const-mod1.volatile[Internal]
+    mod1::TRAIT1_GEN_REF.do_something(0u8);
+
+    //~ MONO_ITEM fn mod1::id::<char> @@ vtable_through_const-mod1.volatile[External]
+    mod1::ID_CHAR('x');
+
+    0
+}

tests/codegen-units/polymorphization/unused_type_parameters.rs

@@ -0,0 +1,322 @@
+// compile-flags:-Zpolymorphize=on -Zprint-mono-items=lazy -Copt-level=1
+
+#![crate_type = "rlib"]
+
+// This test checks that the polymorphization analysis correctly reduces the
+// generated mono items.
+
+mod functions {
+    // Function doesn't have any type parameters to be unused.
+    pub fn no_parameters() {}
+
+//~ MONO_ITEM fn functions::no_parameters
+
+    // Function has an unused type parameter.
+    pub fn unused<T>() {
+    }
+
+//~ MONO_ITEM fn functions::unused::<T>
+
+    // Function uses type parameter in value of a binding.
+    pub fn used_binding_value<T: Default>() {
+        let _: T = Default::default();
+    }
+
+//~ MONO_ITEM fn functions::used_binding_value::<u32>
+//~ MONO_ITEM fn functions::used_binding_value::<u64>
+
+    // Function uses type parameter in type of a binding.
+    pub fn used_binding_type<T>() {
+        let _: Option<T> = None;
+    }
+
+//~ MONO_ITEM fn functions::used_binding_type::<u32>
+//~ MONO_ITEM fn functions::used_binding_type::<u64>
+
+    // Function uses type parameter in argument.
+    pub fn used_argument<T>(_: T) {
+    }
+
+//~ MONO_ITEM fn functions::used_argument::<u32>
+//~ MONO_ITEM fn functions::used_argument::<u64>
+//
+    // Function uses type parameter in substitutions to another function.
+    pub fn used_substs<T>() {
+        unused::<T>()
+    }
+
+//~ MONO_ITEM fn functions::used_substs::<u32>
+//~ MONO_ITEM fn functions::used_substs::<u64>
+}
+
+
+mod closures {
+    // Function doesn't have any type parameters to be unused.
+    pub fn no_parameters() {
+        let _ = || {};
+    }
+
+//~ MONO_ITEM fn closures::no_parameters
+
+    // Function has an unused type parameter in parent and closure.
+    pub fn unused<T>() -> u32 {
+        let add_one = |x: u32| x + 1;
+        add_one(3)
+    }
+
+//~ MONO_ITEM fn closures::unused::<T>::{closure#0}
+//~ MONO_ITEM fn closures::unused::<T>
+
+    // Function has an unused type parameter in closure, but not in parent.
+    pub fn used_parent<T: Default>() -> u32 {
+        let _: T = Default::default();
+        let add_one = |x: u32| x + 1;
+        add_one(3)
+    }
+
+//~ MONO_ITEM fn closures::used_parent::<T>::{closure#0}
+//~ MONO_ITEM fn closures::used_parent::<u32>
+//~ MONO_ITEM fn closures::used_parent::<u64>
+
+    // Function uses type parameter in value of a binding in closure.
+    pub fn used_binding_value<T: Default>() -> T {
+        let x = || {
+            let y: T = Default::default();
+            y
+        };
+
+        x()
+    }
+
+//~ MONO_ITEM fn closures::used_binding_value::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_binding_value::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_binding_value::<u32>
+//~ MONO_ITEM fn closures::used_binding_value::<u64>
+
+    // Function uses type parameter in type of a binding in closure.
+    pub fn used_binding_type<T>() -> Option<T> {
+        let x = || {
+            let y: Option<T> = None;
+            y
+        };
+
+        x()
+    }
+
+//~ MONO_ITEM fn closures::used_binding_type::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_binding_type::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_binding_type::<u32>
+//~ MONO_ITEM fn closures::used_binding_type::<u64>
+
+    // Function and closure uses type parameter in argument.
+    pub fn used_argument<T>(t: T) -> u32 {
+        let x = |_: T| 3;
+        x(t)
+    }
+
+//~ MONO_ITEM fn closures::used_argument::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_argument::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_argument::<u32>
+//~ MONO_ITEM fn closures::used_argument::<u64>
+
+    // Closure uses type parameter in argument.
+    pub fn used_argument_closure<T: Default>() -> u32 {
+        let t: T = Default::default();
+        let x = |_: T| 3;
+        x(t)
+    }
+
+//~ MONO_ITEM fn closures::used_argument_closure::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_argument_closure::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_argument_closure::<u32>
+//~ MONO_ITEM fn closures::used_argument_closure::<u64>
+
+    // Closure uses type parameter as upvar.
+    pub fn used_upvar<T: Default>() -> T {
+        let x: T = Default::default();
+        let y = || x;
+        y()
+    }
+
+//~ MONO_ITEM fn closures::used_upvar::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_upvar::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_upvar::<u32>
+//~ MONO_ITEM fn closures::used_upvar::<u64>
+
+    // Closure uses type parameter in substitutions to another function.
+    pub fn used_substs<T>() {
+        let x = || super::functions::unused::<T>();
+        x()
+    }
+
+//~ MONO_ITEM fn closures::used_substs::<u32>::{closure#0}
+//~ MONO_ITEM fn closures::used_substs::<u64>::{closure#0}
+//~ MONO_ITEM fn closures::used_substs::<u32>
+//~ MONO_ITEM fn closures::used_substs::<u64>
+}
+
+mod methods {
+    pub struct Foo<F>(F);
+
+    impl<F: Default> Foo<F> {
+        // Function has an unused type parameter from impl.
+        pub fn unused_impl() {
+        }
+
+//~ MONO_ITEM fn methods::Foo::<F>::unused_impl
+
+        // Function has an unused type parameter from impl and fn.
+        pub fn unused_both<G: Default>() {
+        }
+
+//~ MONO_ITEM fn methods::Foo::<F>::unused_both::<G>
+
+        // Function uses type parameter from impl.
+        pub fn used_impl() {
+            let _: F = Default::default();
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::used_impl
+//~ MONO_ITEM fn methods::Foo::<u64>::used_impl
+
+        // Function uses type parameter from impl.
+        pub fn used_fn<G: Default>() {
+            let _: G = Default::default();
+        }
+
+//~ MONO_ITEM fn methods::Foo::<F>::used_fn::<u32>
+//~ MONO_ITEM fn methods::Foo::<F>::used_fn::<u64>
+
+        // Function uses type parameter from impl.
+        pub fn used_both<G: Default>() {
+            let _: F = Default::default();
+            let _: G = Default::default();
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::used_both::<u32>
+//~ MONO_ITEM fn methods::Foo::<u64>::used_both::<u64>
+
+        // Function uses type parameter in substitutions to another function.
+        pub fn used_substs() {
+            super::functions::unused::<F>()
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::used_substs
+//~ MONO_ITEM fn methods::Foo::<u64>::used_substs
+
+        // Function has an unused type parameter from impl and fn.
+        pub fn closure_unused_all<G: Default>() -> u32 {
+            let add_one = |x: u32| x + 1;
+            add_one(3)
+        }
+
+//~ MONO_ITEM fn methods::Foo::<F>::closure_unused_all::<G>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<F>::closure_unused_all::<G>
+
+        // Function uses type parameter from impl and fn in closure.
+        pub fn closure_used_both<G: Default>() -> u32 {
+            let add_one = |x: u32| {
+                let _: F = Default::default();
+                let _: G = Default::default();
+                x + 1
+            };
+
+            add_one(3)
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_both::<u32>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_both::<u64>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_both::<u32>
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_both::<u64>
+
+        // Function uses type parameter from fn in closure.
+        pub fn closure_used_fn<G: Default>() -> u32 {
+            let add_one = |x: u32| {
+                let _: G = Default::default();
+                x + 1
+            };
+
+            add_one(3)
+        }
+
+//~ MONO_ITEM fn methods::Foo::<F>::closure_used_fn::<u32>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<F>::closure_used_fn::<u64>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<F>::closure_used_fn::<u32>
+//~ MONO_ITEM fn methods::Foo::<F>::closure_used_fn::<u64>
+
+        // Function uses type parameter from impl in closure.
+        pub fn closure_used_impl<G: Default>() -> u32 {
+            let add_one = |x: u32| {
+                let _: F = Default::default();
+                x + 1
+            };
+
+            add_one(3)
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_impl::<G>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_impl::<G>::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_impl::<G>
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_impl::<G>
+
+        // Closure uses type parameter in substitutions to another function.
+        pub fn closure_used_substs() {
+            let x = || super::functions::unused::<F>();
+            x()
+        }
+
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_substs::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_substs::{closure#0}
+//~ MONO_ITEM fn methods::Foo::<u32>::closure_used_substs
+//~ MONO_ITEM fn methods::Foo::<u64>::closure_used_substs
+    }
+}
+
+
+
+fn dispatch<T: Default>() {
+    functions::no_parameters();
+    functions::unused::<T>();
+    functions::used_binding_value::<T>();
+    functions::used_binding_type::<T>();
+    functions::used_argument::<T>(Default::default());
+    functions::used_substs::<T>();
+
+    closures::no_parameters();
+    let _ = closures::unused::<T>();
+    let _ = closures::used_parent::<T>();
+    let _ = closures::used_binding_value::<T>();
+    let _ = closures::used_binding_type::<T>();
+    let _ = closures::used_argument::<T>(Default::default());
+    let _ = closures::used_argument_closure::<T>();
+    let _ = closures::used_upvar::<T>();
+    let _ = closures::used_substs::<T>();
+
+    methods::Foo::<T>::unused_impl();
+    methods::Foo::<T>::unused_both::<T>();
+    methods::Foo::<T>::used_impl();
+    methods::Foo::<T>::used_fn::<T>();
+    methods::Foo::<T>::used_both::<T>();
+    methods::Foo::<T>::used_substs();
+    let _ = methods::Foo::<T>::closure_unused_all::<T>();
+    let _ = methods::Foo::<T>::closure_used_both::<T>();
+    let _ = methods::Foo::<T>::closure_used_impl::<T>();
+    let _ = methods::Foo::<T>::closure_used_fn::<T>();
+    let _ = methods::Foo::<T>::closure_used_substs();
+}
+
+//~ MONO_ITEM fn dispatch::<u32>
+//~ MONO_ITEM fn dispatch::<u64>
+
+pub fn foo() {
+    // Generate two copies of each function to check that where the type parameter is unused,
+    // there is only a single copy.
+    dispatch::<u32>();
+    dispatch::<u64>();
+}
+
+//~ MONO_ITEM fn foo @@ unused_type_parameters-cgu.0[External]
+
+// These are all the items that aren't relevant to the test.
+//~ MONO_ITEM fn <u32 as std::default::Default>::default
+//~ MONO_ITEM fn <u64 as std::default::Default>::default