Rollup merge of rust-lang#119759 - sfzhu93:master, r=cjgillot

Add FileCheck annotations to dataflow-const-prop tests

part of rust-lang#116971.

A few shadowing variable names are changed, so that it is easier to match the variable names in MIR using FileCheck syntax.

Also, there's a FIXME in [enum.rs](https://github.com/rust-lang/rust/pull/119759/files#diff-7621f55327838e489a95ac99ae1e6126b37c57aff582594e6bee9d7e7e56fc58) because the MIR looks suspicious to me. It has been explained in the comments.

r? cjgillot

Author: matthiaskrgr

tests/mir-opt/dataflow-const-prop/array_index.rs

@@ -1,9 +1,21 @@
-// skip-filecheck
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 // unit-test: DataflowConstProp
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 
 // EMIT_MIR array_index.main.DataflowConstProp.diff
+
+// CHECK-LABEL: fn main() -> () {
 fn main() {
+    // CHECK: let mut [[array_lit:_.*]]: [u32; 4];
+    // CHECK:     debug x => [[x:_.*]];
+
+    // CHECK:       [[array_lit]] = [const 0_u32, const 1_u32, const 2_u32, const 3_u32];
+    // CHECK-NOT:   {{_.*}} = Len(
+    // CHECK-NOT:   {{_.*}} = Lt(
+    // CHECK-NOT:   assert(move _
+    // CHECK:       {{_.*}} = const 4_usize;
+    // CHECK:       {{_.*}} = const true;
+    // CHECK:       assert(const true
+    // CHECK:       [[x]] = [[array_lit]][2 of 3];
     let x: u32 = [0, 1, 2, 3][2];
 }

tests/mir-opt/dataflow-const-prop/boolean_identities.rs

@@ -1,11 +1,18 @@
-// skip-filecheck
 // unit-test: DataflowConstProp
 
 // EMIT_MIR boolean_identities.test.DataflowConstProp.diff
+
+// CHECK-LABEL: fn test(
 pub fn test(x: bool, y: bool) -> bool {
+    // CHECK-NOT: BitAnd(
+    // CHECK-NOT: BitOr(
     (y | true) & (x & false)
+    // CHECK: _0 = const false;
+    // CHECK-NOT: BitAnd(
+    // CHECK-NOT: BitOr(
 }
 
+// CHECK-LABEL: fn main(
 fn main() {
     test(true, false);
 }

tests/mir-opt/dataflow-const-prop/cast.rs

@@ -1,8 +1,14 @@
-// skip-filecheck
 // unit-test: DataflowConstProp
 
 // EMIT_MIR cast.main.DataflowConstProp.diff
+
+// CHECK-LABEL: fn main(
 fn main() {
+    // CHECK: debug a => [[a:_.*]];
+    // CHECK: debug b => [[b:_.*]];
+
+    // CHECK: [[a]] = const 257_i32;
     let a = 257;
+    // CHECK: [[b]] = const 2_u8;
     let b = a as u8 + 1;
 }

tests/mir-opt/dataflow-const-prop/checked.rs

@@ -1,15 +1,32 @@
-// skip-filecheck
 // unit-test: DataflowConstProp
 // compile-flags: -Coverflow-checks=on
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 
 // EMIT_MIR checked.main.DataflowConstProp.diff
 #[allow(arithmetic_overflow)]
+
+// CHECK-LABEL: fn main(
 fn main() {
+    // CHECK: debug a => [[a:_.*]];
+    // CHECK: debug b => [[b:_.*]];
+    // CHECK: debug c => [[c:_.*]];
+    // CHECK: debug d => [[d:_.*]];
+    // CHECK: debug e => [[e:_.*]];
+
+    // CHECK: [[a]] = const 1_i32;
     let a = 1;
+
+    // CHECK: [[b]] = const 2_i32;
     let b = 2;
+
+    // CHECK: assert(!const false,
+    // CHECK: [[c]] = const 3_i32;
     let c = a + b;
 
+    // CHECK: [[d]] = const _;
     let d = i32::MAX;
+
+    // CHECK: assert(!const true,
+    // CHECK: [[e]] = const i32::MIN;
     let e = d + 1;
 }

tests/mir-opt/dataflow-const-prop/default_boxed_slice.rs

@@ -1,18 +1,29 @@
-// skip-filecheck
 // unit-test: DataflowConstProp
 // compile-flags: -Zmir-enable-passes=+GVN,+Inline
 // ignore-debug assertions change the output MIR
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 
+// This test is to check ICE in issue [#115789](https://github.com/rust-lang/rust/issues/115789).
+
 struct A {
     foo: Box<[bool]>,
 }
 
 // EMIT_MIR default_boxed_slice.main.GVN.diff
 // EMIT_MIR default_boxed_slice.main.DataflowConstProp.diff
+
+// CHECK-LABEL: fn main(
 fn main() {
     // ConstProp will create a constant of type `Box<[bool]>`.
+    // FIXME: it is not yet a constant.
+
     // Verify that `DataflowConstProp` does not ICE trying to dereference it directly.
+
+    // CHECK: debug a => [[a:_.*]];
+    // We may check other inlined functions as well...
+
+    // CHECK: {{_.*}} = Box::<[bool]>(
+    // FIXME: should be `{{_.*}} = const Box::<[bool]>`
     let a: A = A { foo: Box::default() };
 }

tests/mir-opt/dataflow-const-prop/enum.constant.DataflowConstProp.32bit.diff

@@ -14,10 +14,10 @@
               debug x => _2;
           }
           scope 3 {
-              debug x => _4;
+              debug x1 => _4;
           }
           scope 4 {
-              debug x => _5;
+              debug x2 => _5;
           }
       }
 

tests/mir-opt/dataflow-const-prop/enum.constant.DataflowConstProp.64bit.diff

@@ -14,10 +14,10 @@
               debug x => _2;
           }
           scope 3 {
-              debug x => _4;
+              debug x1 => _4;
           }
           scope 4 {
-              debug x => _5;
+              debug x2 => _5;
           }
       }
 

tests/mir-opt/dataflow-const-prop/enum.multiple.DataflowConstProp.32bit.diff

@@ -14,7 +14,7 @@
           let _6: u8;
           let _8: u8;
           scope 2 {
-              debug x => _6;
+              debug x2 => _6;
               let _9: u8;
               scope 4 {
                   debug y => _9;

tests/mir-opt/dataflow-const-prop/enum.multiple.DataflowConstProp.64bit.diff

@@ -14,7 +14,7 @@
           let _6: u8;
           let _8: u8;
           scope 2 {
-              debug x => _6;
+              debug x2 => _6;
               let _9: u8;
               scope 4 {
                   debug y => _9;

tests/mir-opt/dataflow-const-prop/enum.rs

@@ -1,4 +1,3 @@
-// skip-filecheck
 // unit-test: DataflowConstProp
 // EMIT_MIR_FOR_EACH_BIT_WIDTH
 
@@ -13,34 +12,76 @@ enum E {
 }
 
 // EMIT_MIR enum.simple.DataflowConstProp.diff
+
+// CHECK-LABEL: fn simple(
 fn simple() {
+    // CHECK: debug e => [[e:_.*]];
+    // CHECK: debug x => [[x:_.*]];
+    // CHECK: [[e]] = const E::V1(0_i32);
     let e = E::V1(0);
-    let x = match e { E::V1(x) => x, E::V2(x) => x };
+
+    // CHECK: switchInt(const 0_isize) -> [0: [[target_bb:bb.*]], 1: bb1, otherwise: bb2];
+    // CHECK: [[target_bb]]: {
+    // CHECK:     [[x]] = const 0_i32;
+    let x = match e { E::V1(x1) => x1, E::V2(x2) => x2 };
 }
 
 // EMIT_MIR enum.constant.DataflowConstProp.diff
+
+// CHECK-LABEL: fn constant(
 fn constant() {
+    // CHECK: debug e => [[e:_.*]];
+    // CHECK: debug x => [[x:_.*]];
     const C: E = E::V1(0);
+
+    // CHECK: [[e]] = const _;
     let e = C;
-    let x = match e { E::V1(x) => x, E::V2(x) => x };
+    // CHECK: switchInt(const 0_isize) -> [0: [[target_bb:bb.*]], 1: bb1, otherwise: bb2];
+    // CHECK: [[target_bb]]: {
+    // CHECK:     [[x]] = const 0_i32;
+    let x = match e { E::V1(x1) => x1, E::V2(x2) => x2 };
 }
 
 // EMIT_MIR enum.statics.DataflowConstProp.diff
+
+// CHECK-LABEL: fn statics(
 fn statics() {
+    // CHECK: debug e1 => [[e1:_.*]];
+    // CHECK: debug x1 => [[x1:_.*]];
+    // CHECK: debug e2 => [[e2:_.*]];
+    // CHECK: debug x2 => [[x2:_.*]];
+
     static C: E = E::V1(0);
-    let e = C;
-    let x = match e { E::V1(x) => x, E::V2(x) => x };
+
+    // CHECK: [[e1]] = const E::V1(0_i32);
+    let e1 = C;
+    // CHECK: switchInt(const 0_isize) -> [0: [[target_bb:bb.*]], 1: bb1, otherwise: bb2];
+    // CHECK: [[target_bb]]: {
+    // CHECK:     [[x1]] = const 0_i32;
+    let x1 = match e1 { E::V1(x11) => x11, E::V2(x12) => x12 };
 
     static RC: &E = &E::V2(4);
-    let e = RC;
-    let x = match e { E::V1(x) => x, E::V2(x) => x };
+
+    // CHECK: [[t:_.*]] = const {alloc2: &&E};
+    // CHECK: [[e2]] = (*[[t]]);
+    let e2 = RC;
+
+    // CHECK: switchInt({{move _.*}}) -> {{.*}}
+    // FIXME: add checks for x2. Currently, their MIRs are not symmetric in the two
+    // switch branches.
+    // One is `_9 = &(*_12) and another is `_9 = _11`. It is different from what we can
+    // get by printing MIR directly. It is better to check if there are any bugs in the
+    // MIR passes around this stage.
+    let x2 = match e2 { E::V1(x21) => x21, E::V2(x22) => x22 };
 }
 
 #[rustc_layout_scalar_valid_range_start(1)]
 #[rustc_nonnull_optimization_guaranteed]
 struct NonZeroUsize(usize);
 
 // EMIT_MIR enum.mutate_discriminant.DataflowConstProp.diff
+
+// CHECK-LABEL: fn mutate_discriminant(
 #[custom_mir(dialect = "runtime", phase = "post-cleanup")]
 fn mutate_discriminant() -> u8 {
     mir!(
@@ -50,7 +91,11 @@ fn mutate_discriminant() -> u8 {
             // This assignment overwrites the niche in which the discriminant is stored.
             place!(Field(Field(Variant(x, 1), 0), 0)) = 0_usize;
             // So we cannot know the value of this discriminant.
+
+            // CHECK: [[a:_.*]] = discriminant({{_.*}});
             let a = Discriminant(x);
+
+            // CHECK: switchInt([[a]]) -> [0: {{bb.*}}, otherwise: {{bb.*}}];
             match a {
                 0 => bb1,
                 _ => bad,
@@ -68,18 +113,33 @@ fn mutate_discriminant() -> u8 {
 }
 
 // EMIT_MIR enum.multiple.DataflowConstProp.diff
+// CHECK-LABEL: fn multiple(
 fn multiple(x: bool, i: u8) {
+    // CHECK: debug x => [[x:_.*]];
+    // CHECK: debug e => [[e:_.*]];
+    // CHECK: debug x2 => [[x2:_.*]];
+    // CHECK: debug y => [[y:_.*]];
     let e = if x {
+        // CHECK: [[e]] = Option::<u8>::Some(move {{_.*}});
         Some(i)
     } else {
+        // CHECK: [[e]] = Option::<u8>::None;
         None
     };
     // The dataflow state must have:
     //   discriminant(e) => Top
     //   (e as Some).0 => Top
-    let x = match e { Some(i) => i, None => 0 };
-    // Therefore, `x` should be `Top` here, and no replacement shall happen.
-    let y = x;
+    // CHECK: [[x2]] = const 0_u8;
+    // CHECK: [[some:_.*]] = (({{_.*}} as Some).0: u8)
+    // CHECK: [[x2]] = [[some]];
+    let x2 = match e { Some(i) => i, None => 0 };
+
+    // Therefore, `x2` should be `Top` here, and no replacement shall happen.
+
+    // CHECK-NOT: [[y]] = const
+    // CHECK: [[y]] = [[x2]];
+    // CHECK-NOT: [[y]] = const
+    let y = x2;
 }
 
 fn main() {

tests/mir-opt/dataflow-const-prop/enum.simple.DataflowConstProp.32bit.diff

@@ -14,10 +14,10 @@
               debug x => _2;
           }
           scope 3 {
-              debug x => _4;
+              debug x1 => _4;
           }
           scope 4 {
-              debug x => _5;
+              debug x2 => _5;
           }
       }
 

tests/mir-opt/dataflow-const-prop/enum.simple.DataflowConstProp.64bit.diff

@@ -14,10 +14,10 @@
               debug x => _2;
           }
           scope 3 {
-              debug x => _4;
+              debug x1 => _4;
           }
           scope 4 {
-              debug x => _5;
+              debug x2 => _5;
           }
       }
 

tests/mir-opt/dataflow-const-prop/enum.statics.DataflowConstProp.32bit.diff

@@ -9,34 +9,34 @@
       let mut _8: &&E;
       let mut _10: isize;
       scope 1 {
-          debug e => _1;
+          debug e1 => _1;
           let _3: i32;
           let _5: i32;
           let _6: i32;
           scope 2 {
-              debug x => _3;
+              debug x1 => _3;
               let _7: &E;
               scope 5 {
-                  debug e => _7;
+                  debug e2 => _7;
                   let _9: &i32;
                   let _11: &i32;
                   let _12: &i32;
                   scope 6 {
-                      debug x => _9;
+                      debug x2 => _9;
                   }
                   scope 7 {
-                      debug x => _11;
+                      debug x21 => _11;
                   }
                   scope 8 {
-                      debug x => _12;
+                      debug x22 => _12;
                   }
               }
           }
           scope 3 {
-              debug x => _5;
+              debug x11 => _5;
           }
           scope 4 {
-              debug x => _6;
+              debug x12 => _6;
           }
       }