Fixed conflict with drop elaboration and coverage

richkadel · richkadel · commit 1d6b455fb476 · 2020-12-15T23:33:47.000-08:00
See #80045 (comment) Coverage statements are moved to the beginning of the BCB. This does also affect what's counted before a panic, changing some results, but I think these results may even be preferred? In any case, there are no guarantees about what's counted when a panic occurs (by design).
diff --git a/compiler/rustc_mir/src/transform/coverage/mod.rs b/compiler/rustc_mir/src/transform/coverage/mod.rs
@@ -310,7 +310,7 @@ impl<'a, 'tcx> Instrumentor<'a, 'tcx> {
             inject_statement(
                 self.mir_body,
                 counter_kind,
-                self.bcb_last_bb(bcb),
+                self.bcb_leader_bb(bcb),
                 Some(make_code_region(file_name, &self.source_file, span, body_span)),
             );
         }
@@ -470,7 +470,7 @@ fn inject_statement(
             code_region: some_code_region,
         }),
     };
-    data.statements.push(statement);
+    data.statements.insert(0, statement);
 }
 
 // Non-code expressions are injected into the coverage map, without generating executable code.
diff --git a/src/test/mir-opt/coverage_graphviz.bar.InstrumentCoverage.0.dot b/src/test/mir-opt/coverage_graphviz.bar.InstrumentCoverage.0.dot
@@ -2,5 +2,5 @@ digraph Cov_0_4 {
     graph [fontname="Courier, monospace"];
     node [fontname="Courier, monospace"];
     edge [fontname="Courier, monospace"];
-    bcb0__Cov_0_4 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb0</td></tr><tr><td align="left" balign="left"></td></tr><tr><td align="left" balign="left">Counter(bcb0) at 18:1-20:2<br/>    19:5-19:9: @0[0]: _0 = const true<br/>    20:2-20:2: @0.Return: return</td></tr><tr><td align="left" balign="left">bb0: Return</td></tr></table>>];
+    bcb0__Cov_0_4 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb0</td></tr><tr><td align="left" balign="left"></td></tr><tr><td align="left" balign="left">Counter(bcb0) at 18:1-20:2<br/>    19:5-19:9: @0[0]: Coverage::Counter(1) for $DIR/coverage_graphviz.rs:18:1 - 20:2<br/>    20:2-20:2: @0.Return: return</td></tr><tr><td align="left" balign="left">bb0: Return</td></tr></table>>];
 }
diff --git a/src/test/mir-opt/coverage_graphviz.main.InstrumentCoverage.0.dot b/src/test/mir-opt/coverage_graphviz.main.InstrumentCoverage.0.dot
@@ -2,7 +2,7 @@ digraph Cov_0_3 {
     graph [fontname="Courier, monospace"];
     node [fontname="Courier, monospace"];
     edge [fontname="Courier, monospace"];
-    bcb2__Cov_0_3 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb2</td></tr><tr><td align="left" balign="left">Expression(bcb0 - bcb1) at 13:10-13:10<br/>    13:10-13:10: @4[0]: _1 = const ()</td></tr><tr><td align="left" balign="left">bb4: Goto</td></tr></table>>];
+    bcb2__Cov_0_3 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb2</td></tr><tr><td align="left" balign="left">Expression(bcb0 - bcb1) at 13:10-13:10<br/>    13:10-13:10: @4[0]: Coverage::Expression(4294967295) = 1 - 2 for $DIR/coverage_graphviz.rs:13:10 - 13:11</td></tr><tr><td align="left" balign="left">bb4: Goto</td></tr></table>>];
     bcb1__Cov_0_3 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb1</td></tr><tr><td align="left" balign="left">Counter(bcb1) at 12:13-12:18<br/>    12:13-12:18: @5[0]: _0 = const ()<br/>Expression(bcb1 + 0) at 15:2-15:2<br/>    15:2-15:2: @5.Return: return</td></tr><tr><td align="left" balign="left">bb3: FalseEdge</td></tr><tr><td align="left" balign="left">bb5: Return</td></tr></table>>];
     bcb0__Cov_0_3 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb0</td></tr><tr><td align="left" balign="left"></td></tr><tr><td align="left" balign="left">Counter(bcb0) at 9:1-11:17<br/>    11:12-11:17: @1.Call: _2 = bar() -&gt; [return: bb2, unwind: bb6]<br/>    11:12-11:17: @2[0]: FakeRead(ForMatchedPlace, _2)</td></tr><tr><td align="left" balign="left">bb0: FalseUnwind<br/>bb1: Call</td></tr><tr><td align="left" balign="left">bb2: SwitchInt</td></tr></table>>];
     bcb2__Cov_0_3 -> bcb0__Cov_0_3 [label=<>];
diff --git a/src/test/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff b/src/test/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff
@@ -5,8 +5,8 @@
       let mut _0: bool;                    // return place in scope 0 at /the/src/instrument_coverage.rs:19:13: 19:17
   
       bb0: {
-          _0 = const true;                 // scope 0 at /the/src/instrument_coverage.rs:20:5: 20:9
 +         Coverage::Counter(1) for /the/src/instrument_coverage.rs:19:1 - 21:2; // scope 0 at /the/src/instrument_coverage.rs:21:2: 21:2
+          _0 = const true;                 // scope 0 at /the/src/instrument_coverage.rs:20:5: 20:9
           return;                          // scope 0 at /the/src/instrument_coverage.rs:21:2: 21:2
       }
   }
diff --git a/src/test/mir-opt/instrument_coverage.main.InstrumentCoverage.diff b/src/test/mir-opt/instrument_coverage.main.InstrumentCoverage.diff
@@ -8,6 +8,7 @@
       let mut _3: !;                       // in scope 0 at /the/src/instrument_coverage.rs:12:18: 14:10
   
       bb0: {
++         Coverage::Counter(1) for /the/src/instrument_coverage.rs:10:1 - 12:17; // scope 0 at /the/src/instrument_coverage.rs:11:5: 15:6
           falseUnwind -> [real: bb1, cleanup: bb6]; // scope 0 at /the/src/instrument_coverage.rs:11:5: 15:6
       }
   
@@ -21,26 +22,25 @@
   
       bb2: {
           FakeRead(ForMatchedPlace, _2);   // scope 0 at /the/src/instrument_coverage.rs:12:12: 12:17
-+         Coverage::Counter(1) for /the/src/instrument_coverage.rs:10:1 - 12:17; // scope 0 at /the/src/instrument_coverage.rs:12:9: 14:10
           switchInt(_2) -> [false: bb4, otherwise: bb3]; // scope 0 at /the/src/instrument_coverage.rs:12:9: 14:10
       }
   
       bb3: {
++         Coverage::Expression(4294967294) = 2 + 0 for /the/src/instrument_coverage.rs:16:1 - 16:2; // scope 0 at /the/src/instrument_coverage.rs:12:9: 14:10
++         Coverage::Counter(2) for /the/src/instrument_coverage.rs:13:13 - 13:18; // scope 0 at /the/src/instrument_coverage.rs:12:9: 14:10
           falseEdge -> [real: bb5, imaginary: bb4]; // scope 0 at /the/src/instrument_coverage.rs:12:9: 14:10
       }
   
       bb4: {
++         Coverage::Expression(4294967295) = 1 - 2 for /the/src/instrument_coverage.rs:14:10 - 14:11; // scope 0 at /the/src/instrument_coverage.rs:11:5: 15:6
           _1 = const ();                   // scope 0 at /the/src/instrument_coverage.rs:14:10: 14:10
           StorageDead(_2);                 // scope 0 at /the/src/instrument_coverage.rs:15:5: 15:6
-+         Coverage::Expression(4294967295) = 1 - 2 for /the/src/instrument_coverage.rs:14:10 - 14:11; // scope 0 at /the/src/instrument_coverage.rs:11:5: 15:6
           goto -> bb0;                     // scope 0 at /the/src/instrument_coverage.rs:11:5: 15:6
       }
   
       bb5: {
           _0 = const ();                   // scope 0 at /the/src/instrument_coverage.rs:13:13: 13:18
           StorageDead(_2);                 // scope 0 at /the/src/instrument_coverage.rs:15:5: 15:6
-+         Coverage::Counter(2) for /the/src/instrument_coverage.rs:13:13 - 13:18; // scope 0 at /the/src/instrument_coverage.rs:16:2: 16:2
-+         Coverage::Expression(4294967294) = 2 + 0 for /the/src/instrument_coverage.rs:16:1 - 16:2; // scope 0 at /the/src/instrument_coverage.rs:16:2: 16:2
           return;                          // scope 0 at /the/src/instrument_coverage.rs:16:2: 16:2
       }
   
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.assert.json b/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.assert.json
@@ -17,14 +17,14 @@
             },
             "lines": {
               "count": 15,
-              "covered": 12,
-              "percent": 80
+              "covered": 13,
+              "percent": 86.66666666666667
             },
             "regions": {
               "count": 14,
-              "covered": 12,
-              "notcovered": 2,
-              "percent": 85.71428571428571
+              "covered": 13,
+              "notcovered": 1,
+              "percent": 92.85714285714286
             }
           }
         }
@@ -42,14 +42,14 @@
         },
         "lines": {
           "count": 15,
-          "covered": 12,
-          "percent": 80
+          "covered": 13,
+          "percent": 86.66666666666667
         },
         "regions": {
           "count": 14,
-          "covered": 12,
-          "notcovered": 2,
-          "percent": 85.71428571428571
+          "covered": 13,
+          "notcovered": 1,
+          "percent": 92.85714285714286
         }
       }
     }
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.overflow.json b/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.overflow.json
@@ -17,14 +17,14 @@
             },
             "lines": {
               "count": 23,
-              "covered": 19,
-              "percent": 82.6086956521739
+              "covered": 21,
+              "percent": 91.30434782608695
             },
             "regions": {
               "count": 13,
-              "covered": 11,
-              "notcovered": 2,
-              "percent": 84.61538461538461
+              "covered": 12,
+              "notcovered": 1,
+              "percent": 92.3076923076923
             }
           }
         }
@@ -42,14 +42,14 @@
         },
         "lines": {
           "count": 23,
-          "covered": 19,
-          "percent": 82.6086956521739
+          "covered": 21,
+          "percent": 91.30434782608695
         },
         "regions": {
           "count": 13,
-          "covered": 11,
-          "notcovered": 2,
-          "percent": 84.61538461538461
+          "covered": 12,
+          "notcovered": 1,
+          "percent": 92.3076923076923
         }
       }
     }
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.panic_unwind.json b/src/test/run-make-fulldeps/coverage-reports/expected_export_coverage.panic_unwind.json
@@ -17,14 +17,14 @@
             },
             "lines": {
               "count": 19,
-              "covered": 16,
-              "percent": 84.21052631578947
+              "covered": 17,
+              "percent": 89.47368421052632
             },
             "regions": {
               "count": 13,
-              "covered": 11,
-              "notcovered": 2,
-              "percent": 84.61538461538461
+              "covered": 12,
+              "notcovered": 1,
+              "percent": 92.3076923076923
             }
           }
         }
@@ -42,14 +42,14 @@
         },
         "lines": {
           "count": 19,
-          "covered": 16,
-          "percent": 84.21052631578947
+          "covered": 17,
+          "percent": 89.47368421052632
         },
         "regions": {
           "count": 13,
-          "covered": 11,
-          "notcovered": 2,
-          "percent": 84.61538461538461
+          "covered": 12,
+          "notcovered": 1,
+          "percent": 92.3076923076923
         }
       }
     }
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.assert.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.assert.txt
@@ -9,13 +9,13 @@
     8|       |
     9|      1|fn main() -> Result<(),u8> {
    10|      1|    let mut countdown = 10;
-   11|     10|    while countdown > 0 {
-   12|     10|        if countdown == 1 {
-   13|      0|            might_fail_assert(3);
+   11|     11|    while countdown > 0 {
+   12|     11|        if countdown == 1 {
+   13|      1|            might_fail_assert(3);
    14|     10|        } else if countdown < 5 {
    15|      3|            might_fail_assert(2);
    16|      6|        }
-   17|      9|        countdown -= 1;
+   17|     10|        countdown -= 1;
    18|       |    }
    19|      0|    Ok(())
    20|      0|}
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.overflow.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.overflow.txt
@@ -14,15 +14,15 @@
    14|       |
    15|      1|fn main() -> Result<(),u8> {
    16|      1|    let mut countdown = 10;
-   17|     10|    while countdown > 0 {
-   18|     10|        if countdown == 1 {
-   19|      0|            let result = might_overflow(10);
-   20|      0|            println!("Result: {}", result);
+   17|     11|    while countdown > 0 {
+   18|     11|        if countdown == 1 {
+   19|      1|            let result = might_overflow(10);
+   20|      1|            println!("Result: {}", result);
    21|     10|        } else if countdown < 5 {
    22|      3|            let result = might_overflow(1);
    23|      3|            println!("Result: {}", result);
    24|      6|        }
-   25|      9|        countdown -= 1;
+   25|     10|        countdown -= 1;
    26|       |    }
    27|      0|    Ok(())
    28|      0|}
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.panic_unwind.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.panic_unwind.txt
@@ -12,13 +12,13 @@
    12|       |
    13|      1|fn main() -> Result<(), u8> {
    14|      1|    let mut countdown = 10;
-   15|     10|    while countdown > 0 {
-   16|     10|        if countdown == 1 {
-   17|      0|            might_panic(true);
+   15|     11|    while countdown > 0 {
+   16|     11|        if countdown == 1 {
+   17|      1|            might_panic(true);
    18|     10|        } else if countdown < 5 {
    19|      3|            might_panic(false);
    20|      6|        }
-   21|      9|        countdown -= 1;
+   21|     10|        countdown -= 1;
    22|       |    }
    23|      0|    Ok(())
    24|      0|}
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.assert.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.assert.txt
@@ -20,13 +20,13 @@ Combined regions:
   6:37 -> 6:61 (count=1)
   7:1 -> 7:2 (count=3)
   9:1 -> 10:27 (count=1)
-  11:11 -> 11:24 (count=10)
-  12:12 -> 12:26 (count=10)
-  12:27 -> 14:10 (count=0)
+  11:11 -> 11:24 (count=11)
+  12:12 -> 12:26 (count=11)
+  12:27 -> 14:10 (count=1)
   14:19 -> 14:32 (count=10)
   14:33 -> 16:10 (count=3)
   16:10 -> 16:11 (count=6)
-  17:9 -> 17:23 (count=9)
+  17:9 -> 17:23 (count=10)
   19:5 -> 20:2 (count=0)
 Segment at 4:1 (count = 4), RegionEntry
 Segment at 4:41 (count = 0), Skipped
@@ -40,18 +40,18 @@ Segment at 7:1 (count = 3), RegionEntry
 Segment at 7:2 (count = 0), Skipped
 Segment at 9:1 (count = 1), RegionEntry
 Segment at 10:27 (count = 0), Skipped
-Segment at 11:11 (count = 10), RegionEntry
+Segment at 11:11 (count = 11), RegionEntry
 Segment at 11:24 (count = 0), Skipped
-Segment at 12:12 (count = 10), RegionEntry
+Segment at 12:12 (count = 11), RegionEntry
 Segment at 12:26 (count = 0), Skipped
-Segment at 12:27 (count = 0), RegionEntry
+Segment at 12:27 (count = 1), RegionEntry
 Segment at 14:10 (count = 0), Skipped
 Segment at 14:19 (count = 10), RegionEntry
 Segment at 14:32 (count = 0), Skipped
 Segment at 14:33 (count = 3), RegionEntry
 Segment at 16:10 (count = 6), RegionEntry
 Segment at 16:11 (count = 0), Skipped
-Segment at 17:9 (count = 9), RegionEntry
+Segment at 17:9 (count = 10), RegionEntry
 Segment at 17:23 (count = 0), Skipped
 Segment at 19:5 (count = 0), RegionEntry
 Segment at 20:2 (count = 0), Skipped
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.overflow.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.overflow.txt
@@ -18,13 +18,13 @@ Combined regions:
   7:6 -> 7:7 (count=3)
   8:9 -> 13:2 (count=4)
   15:1 -> 16:27 (count=1)
-  17:11 -> 17:24 (count=10)
-  18:12 -> 18:26 (count=10)
-  18:27 -> 21:10 (count=0)
+  17:11 -> 17:24 (count=11)
+  18:12 -> 18:26 (count=11)
+  18:27 -> 21:10 (count=1)
   21:19 -> 21:32 (count=10)
   21:33 -> 24:10 (count=3)
   24:10 -> 24:11 (count=6)
-  25:9 -> 25:23 (count=9)
+  25:9 -> 25:23 (count=10)
   27:5 -> 28:2 (count=0)
 Segment at 4:1 (count = 4), RegionEntry
 Segment at 5:18 (count = 0), Skipped
@@ -35,18 +35,18 @@ Segment at 8:9 (count = 4), RegionEntry
 Segment at 13:2 (count = 0), Skipped
 Segment at 15:1 (count = 1), RegionEntry
 Segment at 16:27 (count = 0), Skipped
-Segment at 17:11 (count = 10), RegionEntry
+Segment at 17:11 (count = 11), RegionEntry
 Segment at 17:24 (count = 0), Skipped
-Segment at 18:12 (count = 10), RegionEntry
+Segment at 18:12 (count = 11), RegionEntry
 Segment at 18:26 (count = 0), Skipped
-Segment at 18:27 (count = 0), RegionEntry
+Segment at 18:27 (count = 1), RegionEntry
 Segment at 21:10 (count = 0), Skipped
 Segment at 21:19 (count = 10), RegionEntry
 Segment at 21:32 (count = 0), Skipped
 Segment at 21:33 (count = 3), RegionEntry
 Segment at 24:10 (count = 6), RegionEntry
 Segment at 24:11 (count = 0), Skipped
-Segment at 25:9 (count = 9), RegionEntry
+Segment at 25:9 (count = 10), RegionEntry
 Segment at 25:23 (count = 0), Skipped
 Segment at 27:5 (count = 0), RegionEntry
 Segment at 28:2 (count = 0), Skipped
diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.panic_unwind.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage_counters.panic_unwind.txt
@@ -18,13 +18,13 @@ Combined regions:
   6:9 -> 7:26 (count=1)
   8:12 -> 11:2 (count=3)
   13:1 -> 14:27 (count=1)
-  15:11 -> 15:24 (count=10)
-  16:12 -> 16:26 (count=10)
-  16:27 -> 18:10 (count=0)
+  15:11 -> 15:24 (count=11)
+  16:12 -> 16:26 (count=11)
+  16:27 -> 18:10 (count=1)
   18:19 -> 18:32 (count=10)
   18:33 -> 20:10 (count=3)
   20:10 -> 20:11 (count=6)
-  21:9 -> 21:23 (count=9)
+  21:9 -> 21:23 (count=10)
   23:5 -> 24:2 (count=0)
 Segment at 4:1 (count = 4), RegionEntry
 Segment at 4:36 (count = 0), Skipped
@@ -36,18 +36,18 @@ Segment at 8:12 (count = 3), RegionEntry
 Segment at 11:2 (count = 0), Skipped
 Segment at 13:1 (count = 1), RegionEntry
 Segment at 14:27 (count = 0), Skipped
-Segment at 15:11 (count = 10), RegionEntry
+Segment at 15:11 (count = 11), RegionEntry
 Segment at 15:24 (count = 0), Skipped
-Segment at 16:12 (count = 10), RegionEntry
+Segment at 16:12 (count = 11), RegionEntry
 Segment at 16:26 (count = 0), Skipped
-Segment at 16:27 (count = 0), RegionEntry
+Segment at 16:27 (count = 1), RegionEntry
 Segment at 18:10 (count = 0), Skipped
 Segment at 18:19 (count = 10), RegionEntry
 Segment at 18:32 (count = 0), Skipped
 Segment at 18:33 (count = 3), RegionEntry
 Segment at 20:10 (count = 6), RegionEntry
 Segment at 20:11 (count = 0), Skipped
-Segment at 21:9 (count = 9), RegionEntry
+Segment at 21:9 (count = 10), RegionEntry
 Segment at 21:23 (count = 0), Skipped
 Segment at 23:5 (count = 0), RegionEntry
 Segment at 24:2 (count = 0), Skipped

Original file line number	Diff line number	Diff line change
`@@ -2,5 +2,5 @@ digraph Cov_0_4 {`
`2`	`2`	`graph [fontname="Courier, monospace"];`
`3`	`3`	`node [fontname="Courier, monospace"];`
`4`	`4`	`edge [fontname="Courier, monospace"];`
`5`		`- bcb0__Cov_0_4 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb0</td></tr><tr><td align="left" balign="left"></td></tr><tr><td align="left" balign="left">Counter(bcb0) at 18:1-20:2<br/> 19:5-19:9: @0[0]: _0 = const true<br/> 20:2-20:2: @0.Return: return</td></tr><tr><td align="left" balign="left">bb0: Return</td></tr></table>>];`
	`5`	`+ bcb0__Cov_0_4 [shape="none", label=<<table border="0" cellborder="1" cellspacing="0"><tr><td bgcolor="gray" align="center" colspan="1">bcb0</td></tr><tr><td align="left" balign="left"></td></tr><tr><td align="left" balign="left">Counter(bcb0) at 18:1-20:2<br/> 19:5-19:9: @0[0]: Coverage::Counter(1) for $DIR/coverage_graphviz.rs:18:1 - 20:2<br/> 20:2-20:2: @0.Return: return</td></tr><tr><td align="left" balign="left">bb0: Return</td></tr></table>>];`
`6`	`6`	`}`
Original file line number	Diff line number	Diff line change
`@@ -5,8 +5,8 @@`
`5`	`5`	`let mut _0: bool; // return place in scope 0 at /the/src/instrument_coverage.rs:19:13: 19:17`
`6`	`6`
`7`	`7`	`bb0: {`
`8`		`- _0 = const true; // scope 0 at /the/src/instrument_coverage.rs:20:5: 20:9`
`9`	`8`	`+ Coverage::Counter(1) for /the/src/instrument_coverage.rs:19:1 - 21:2; // scope 0 at /the/src/instrument_coverage.rs:21:2: 21:2`
	`9`	`+ _0 = const true; // scope 0 at /the/src/instrument_coverage.rs:20:5: 20:9`
`10`	`10`	`return; // scope 0 at /the/src/instrument_coverage.rs:21:2: 21:2`
`11`	`11`	`}`
`12`	`12`	`}`