Rollup merge of #103464 - JakobDegen:mir-parsing, r=oli-obk

Add support for custom mir

This implements rust-lang/compiler-team#564 . Details about the design, motivation, etc. can be found in there.

r? ```@oli-obk```

8 files changed, 159 insertions, 0 deletions

diff --git a/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir b/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir
new file mode 100644
index 00000000000..4a5ddde4081
--- /dev/null
+++ b/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir
@@ -0,0 +1,14 @@
+// MIR for `immut_ref` after built
+
+fn immut_ref(_1: &i32) -> &i32 {
+    let mut _0: &i32;                    // return place in scope 0 at $DIR/references.rs:+0:30: +0:34
+    let mut _2: *const i32;              // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+
+    bb0: {
+        _2 = &raw const (*_1);           // scope 0 at $DIR/references.rs:+0:1: +0:34
+        Retag([raw] _2);                 // scope 0 at $DIR/references.rs:+0:1: +0:34
+        _0 = &(*_2);                     // scope 0 at $DIR/references.rs:+0:1: +0:34
+        Retag(_0);                       // scope 0 at $DIR/references.rs:+0:1: +0:34
+        return;                          // scope 0 at $DIR/references.rs:+0:1: +0:34
+    }
+}
diff --git a/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir b/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir
new file mode 100644
index 00000000000..ec8509f69d1
--- /dev/null
+++ b/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir
@@ -0,0 +1,14 @@
+// MIR for `mut_ref` after built
+
+fn mut_ref(_1: &mut i32) -> &mut i32 {
+    let mut _0: &mut i32;                // return place in scope 0 at $DIR/references.rs:+0:32: +0:40
+    let mut _2: *mut i32;                // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+
+    bb0: {
+        _2 = &raw mut (*_1);             // scope 0 at $DIR/references.rs:+0:1: +0:40
+        Retag([raw] _2);                 // scope 0 at $DIR/references.rs:+0:1: +0:40
+        _0 = &mut (*_2);                 // scope 0 at $DIR/references.rs:+0:1: +0:40
+        Retag(_0);                       // scope 0 at $DIR/references.rs:+0:1: +0:40
+        return;                          // scope 0 at $DIR/references.rs:+0:1: +0:40
+    }
+}
diff --git a/src/test/mir-opt/building/custom/references.rs b/src/test/mir-opt/building/custom/references.rs
new file mode 100644
index 00000000000..dee85722e86
--- /dev/null
+++ b/src/test/mir-opt/building/custom/references.rs
@@ -0,0 +1,43 @@
+#![feature(custom_mir, core_intrinsics)]
+
+extern crate core;
+use core::intrinsics::mir::*;
+use core::ptr::{addr_of, addr_of_mut};
+
+// EMIT_MIR references.mut_ref.built.after.mir
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+pub fn mut_ref(x: &mut i32) -> &mut i32 {
+    mir!(
+        let t: *mut i32;
+
+        {
+            t = addr_of_mut!(*x);
+            RetagRaw(t);
+            RET = &mut *t;
+            Retag(RET);
+            Return()
+        }
+    )
+}
+
+// EMIT_MIR references.immut_ref.built.after.mir
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+pub fn immut_ref(x: &i32) -> &i32 {
+    mir!(
+        let t: *const i32;
+
+        {
+            t = addr_of!(*x);
+            RetagRaw(t);
+            RET = & *t;
+            Retag(RET);
+            Return()
+        }
+    )
+}
+
+fn main() {
+    let mut x = 5;
+    assert_eq!(*mut_ref(&mut x), 5);
+    assert_eq!(*immut_ref(&x), 5);
+}
diff --git a/src/test/mir-opt/building/custom/simple_assign.rs b/src/test/mir-opt/building/custom/simple_assign.rs
new file mode 100644
index 00000000000..ec6dbe1d052
--- /dev/null
+++ b/src/test/mir-opt/building/custom/simple_assign.rs
@@ -0,0 +1,37 @@
+#![feature(custom_mir, core_intrinsics)]
+
+extern crate core;
+use core::intrinsics::mir::*;
+
+// EMIT_MIR simple_assign.simple.built.after.mir
+#[custom_mir(dialect = "built")]
+pub fn simple(x: i32) -> i32 {
+    mir!(
+        let temp1: i32;
+        let temp2: _;
+
+        {
+            temp1 = x;
+            Goto(exit)
+        }
+
+        exit = {
+            temp2 = Move(temp1);
+            RET = temp2;
+            Return()
+        }
+    )
+}
+
+// EMIT_MIR simple_assign.simple_ref.built.after.mir
+#[custom_mir(dialect = "built")]
+pub fn simple_ref(x: &mut i32) -> &mut i32 {
+    mir!({
+        RET = Move(x);
+        Return()
+    })
+}
+
+fn main() {
+    assert_eq!(5, simple(5));
+}
diff --git a/src/test/mir-opt/building/custom/simple_assign.simple.built.after.mir b/src/test/mir-opt/building/custom/simple_assign.simple.built.after.mir
new file mode 100644
index 00000000000..a5a2834c2e1
--- /dev/null
+++ b/src/test/mir-opt/building/custom/simple_assign.simple.built.after.mir
@@ -0,0 +1,18 @@
+// MIR for `simple` after built
+
+fn simple(_1: i32) -> i32 {
+    let mut _0: i32;                     // return place in scope 0 at $DIR/simple_assign.rs:+0:26: +0:29
+    let mut _2: i32;                     // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+    let mut _3: i32;                     // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL
+
+    bb0: {
+        _2 = _1;                         // scope 0 at $DIR/simple_assign.rs:+0:1: +0:29
+        goto -> bb1;                     // scope 0 at $DIR/simple_assign.rs:+0:1: +0:29
+    }
+
+    bb1: {
+        _3 = move _2;                    // scope 0 at $DIR/simple_assign.rs:+0:1: +0:29
+        _0 = _3;                         // scope 0 at $DIR/simple_assign.rs:+0:1: +0:29
+        return;                          // scope 0 at $DIR/simple_assign.rs:+0:1: +0:29
+    }
+}
diff --git a/src/test/mir-opt/building/custom/simple_assign.simple_ref.built.after.mir b/src/test/mir-opt/building/custom/simple_assign.simple_ref.built.after.mir
new file mode 100644
index 00000000000..6c90f0130a2
--- /dev/null
+++ b/src/test/mir-opt/building/custom/simple_assign.simple_ref.built.after.mir
@@ -0,0 +1,10 @@
+// MIR for `simple_ref` after built
+
+fn simple_ref(_1: &mut i32) -> &mut i32 {
+    let mut _0: &mut i32;                // return place in scope 0 at $DIR/simple_assign.rs:+0:35: +0:43
+
+    bb0: {
+        _0 = move _1;                    // scope 0 at $DIR/simple_assign.rs:+0:1: +0:43
+        return;                          // scope 0 at $DIR/simple_assign.rs:+0:1: +0:43
+    }
+}
diff --git a/src/test/ui/feature-gates/feature-gate-custom_mir.rs b/src/test/ui/feature-gates/feature-gate-custom_mir.rs
new file mode 100644
index 00000000000..0126dde2f7d
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-custom_mir.rs
@@ -0,0 +1,12 @@
+#![feature(core_intrinsics)]
+
+extern crate core;
+
+#[custom_mir(dialect = "built")] //~ ERROR the `#[custom_mir]` attribute is just used for the Rust test suite
+pub fn foo(_x: i32) -> i32 {
+    0
+}
+
+fn main() {
+    assert_eq!(2, foo(2));
+}
diff --git a/src/test/ui/feature-gates/feature-gate-custom_mir.stderr b/src/test/ui/feature-gates/feature-gate-custom_mir.stderr
new file mode 100644
index 00000000000..3c149d30d82
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-custom_mir.stderr
@@ -0,0 +1,11 @@
+error[E0658]: the `#[custom_mir]` attribute is just used for the Rust test suite
+  --> $DIR/feature-gate-custom_mir.rs:5:1
+   |
+LL | #[custom_mir(dialect = "built")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(custom_mir)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.