FileCheck uninhabited_enum_branching.

Author: cjgillot

tests/mir-opt/uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff renamed to tests/mir-opt/uninhabited_enum_branching.byref.UninhabitedEnumBranching.diff

@@ -1,12 +1,12 @@
-- // MIR for `main` before UninhabitedEnumBranching
-+ // MIR for `main` after UninhabitedEnumBranching
+- // MIR for `byref` before UninhabitedEnumBranching
++ // MIR for `byref` after UninhabitedEnumBranching
 
-  fn main() -> () {
+  fn byref() -> () {
       let mut _0: ();
       let _1: Plop;
-      let mut _2: Test1;
+      let mut _2: Test3;
       let _3: &str;
-      let mut _4: &Test1;
+      let mut _4: &Test3;
       let mut _5: isize;
       let _6: &str;
       let _7: &str;
@@ -23,12 +23,12 @@
       bb0: {
           StorageLive(_1);
           StorageLive(_2);
-          _2 = Test1::C;
-          _1 = Plop { xx: const 51_u32, test1: move _2 };
+          _2 = Test3::C;
+          _1 = Plop { xx: const 51_u32, test3: move _2 };
           StorageDead(_2);
           StorageLive(_3);
           StorageLive(_4);
-          _4 = &(_1.1: Test1);
+          _4 = &(_1.1: Test3);
           _5 = discriminant((*_4));
 -         switchInt(move _5) -> [0: bb3, 1: bb4, 2: bb5, 3: bb1, otherwise: bb2];
 +         switchInt(move _5) -> [0: bb12, 1: bb12, 2: bb5, 3: bb1, otherwise: bb12];
@@ -71,7 +71,7 @@
           StorageDead(_4);
           StorageDead(_3);
           StorageLive(_9);
-          _10 = discriminant((_1.1: Test1));
+          _10 = discriminant((_1.1: Test3));
 -         switchInt(move _10) -> [0: bb8, 1: bb9, 2: bb10, 3: bb7, otherwise: bb2];
 +         switchInt(move _10) -> [0: bb12, 1: bb12, 2: bb10, 3: bb7, otherwise: bb12];
       }

tests/mir-opt/uninhabited_enum_branching.custom_discriminant.UninhabitedEnumBranching.diff

@@ -0,0 +1,48 @@
+- // MIR for `custom_discriminant` before UninhabitedEnumBranching
++ // MIR for `custom_discriminant` after UninhabitedEnumBranching
+  
+  fn custom_discriminant() -> () {
+      let mut _0: ();
+      let _1: &str;
+      let mut _2: Test2;
+      let mut _3: isize;
+      let _4: &str;
+  
+      bb0: {
+          StorageLive(_1);
+          StorageLive(_2);
+          _2 = Test2::D;
+          _3 = discriminant(_2);
+-         switchInt(move _3) -> [4: bb3, 5: bb1, otherwise: bb2];
++         switchInt(move _3) -> [4: bb3, 5: bb1, otherwise: bb5];
+      }
+  
+      bb1: {
+          StorageLive(_4);
+          _4 = const "E";
+          _1 = &(*_4);
+          StorageDead(_4);
+          goto -> bb4;
+      }
+  
+      bb2: {
+          unreachable;
+      }
+  
+      bb3: {
+          _1 = const "D";
+          goto -> bb4;
+      }
+  
+      bb4: {
+          StorageDead(_2);
+          StorageDead(_1);
+          _0 = const ();
+          return;
++     }
++ 
++     bb5: {
++         unreachable;
+      }
+  }
+  

tests/mir-opt/uninhabited_enum_branching.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir

@@ -1,11 +1,11 @@
-// skip-filecheck
-enum Empty { }
+// unit-test: UninhabitedEnumBranching
+enum Empty {}
 
 // test matching an enum with uninhabited variants
 enum Test1 {
     A(Empty),
     B(Empty),
-    C
+    C,
 }
 
 // test an enum where the discriminants don't match the variant indexes
@@ -15,17 +15,75 @@ enum Test2 {
     E = 5,
 }
 
-// EMIT_MIR uninhabited_enum_branching.main.UninhabitedEnumBranching.diff
-// EMIT_MIR uninhabited_enum_branching.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir
-fn main() {
+// test matching an enum with uninhabited variants and multiple inhabited
+enum Test3 {
+    A(Empty),
+    B(Empty),
+    C,
+    D,
+}
+
+struct Plop {
+    xx: u32,
+    test3: Test3,
+}
+
+// EMIT_MIR uninhabited_enum_branching.simple.UninhabitedEnumBranching.diff
+fn simple() {
+    // CHECK-LABEL: fn simple(
+    // CHECK: [[discr:_.*]] = discriminant(
+    // CHECK: switchInt(move [[discr]]) -> [0: [[unreachable:bb.*]], 1: [[unreachable]], 2: bb1, otherwise: [[unreachable]]];
+    // CHECK: [[unreachable]]: {
+    // CHECK-NEXT: unreachable;
     match Test1::C {
         Test1::A(_) => "A(Empty)",
         Test1::B(_) => "B(Empty)",
         Test1::C => "C",
     };
+}
 
+// EMIT_MIR uninhabited_enum_branching.custom_discriminant.UninhabitedEnumBranching.diff
+fn custom_discriminant() {
+    // CHECK-LABEL: fn custom_discriminant(
+    // CHECK: [[discr:_.*]] = discriminant(
+    // CHECK: switchInt(move [[discr]]) -> [4: bb3, 5: bb1, otherwise: bb5];
+    // CHECK: bb5: {
+    // CHECK-NEXT: unreachable;
     match Test2::D {
         Test2::D => "D",
         Test2::E => "E",
     };
 }
+
+// EMIT_MIR uninhabited_enum_branching.byref.UninhabitedEnumBranching.diff
+fn byref() {
+    // CHECK-LABEL: fn byref(
+    let plop = Plop { xx: 51, test3: Test3::C };
+
+    // CHECK: [[ref_discr:_.*]] = discriminant((*
+    // CHECK: switchInt(move [[ref_discr]]) -> [0: [[unreachable:bb.*]], 1: [[unreachable]], 2: bb5, 3: bb1, otherwise: [[unreachable]]];
+    match &plop.test3 {
+        Test3::A(_) => "A(Empty)",
+        Test3::B(_) => "B(Empty)",
+        Test3::C => "C",
+        Test3::D => "D",
+    };
+
+    // CHECK: [[discr:_.*]] = discriminant(
+    // CHECK: switchInt(move [[discr]]) -> [0: [[unreachable]], 1: [[unreachable]], 2: bb10, 3: bb7, otherwise: [[unreachable]]];
+    match plop.test3 {
+        Test3::A(_) => "A(Empty)",
+        Test3::B(_) => "B(Empty)",
+        Test3::C => "C",
+        Test3::D => "D",
+    };
+
+    // CHECK: [[unreachable]]: {
+    // CHECK-NEXT: unreachable;
+}
+
+fn main() {
+    simple();
+    custom_discriminant();
+    byref();
+}

tests/mir-opt/uninhabited_enum_branching.rs

@@ -1,25 +1,21 @@
-- // MIR for `main` before UninhabitedEnumBranching
-+ // MIR for `main` after UninhabitedEnumBranching
+- // MIR for `simple` before UninhabitedEnumBranching
++ // MIR for `simple` after UninhabitedEnumBranching
 
-  fn main() -> () {
+  fn simple() -> () {
       let mut _0: ();
       let _1: &str;
       let mut _2: Test1;
       let mut _3: isize;
       let _4: &str;
       let _5: &str;
-      let _6: &str;
-      let mut _7: Test2;
-      let mut _8: isize;
-      let _9: &str;
 
       bb0: {
           StorageLive(_1);
           StorageLive(_2);
           _2 = Test1::C;
           _3 = discriminant(_2);
 -         switchInt(move _3) -> [0: bb3, 1: bb4, 2: bb1, otherwise: bb2];
-+         switchInt(move _3) -> [0: bb9, 1: bb9, 2: bb1, otherwise: bb9];
++         switchInt(move _3) -> [0: bb6, 1: bb6, 2: bb1, otherwise: bb6];
       }
 
       bb1: {
@@ -50,35 +46,11 @@
       bb5: {
           StorageDead(_2);
           StorageDead(_1);
-          StorageLive(_6);
-          StorageLive(_7);
-          _7 = Test2::D;
-          _8 = discriminant(_7);
--         switchInt(move _8) -> [4: bb7, 5: bb6, otherwise: bb2];
-+         switchInt(move _8) -> [4: bb7, 5: bb6, otherwise: bb9];
-      }
-  
-      bb6: {
-          StorageLive(_9);
-          _9 = const "E";
-          _6 = &(*_9);
-          StorageDead(_9);
-          goto -> bb8;
-      }
-  
-      bb7: {
-          _6 = const "D";
-          goto -> bb8;
-      }
-  
-      bb8: {
-          StorageDead(_7);
-          StorageDead(_6);
           _0 = const ();
           return;
 +     }
 + 
-+     bb9: {
++     bb6: {
 +         unreachable;
       }
   }