Coverage tests for remaining TerminatorKinds and async, improve Assert

Tested and validate results for panic unwind, panic abort, assert!()
macro, TerminatorKind::Assert (for example, numeric overflow), and
async/await.

Implemented a previous documented idea to change Assert handling to be
the same as FalseUnwind and Goto, so it doesn't get its own
BasicCoverageBlock anymore. This changed a couple of coverage regions,
but I validated those changes are not any worse than the prior results,
and probably help assure some consistency (even if some people might
disagree with how the code region is consistently computed).

Fixed issue with async/await. AggregateKind::Generator needs to be
handled like AggregateKind::Closure; coverage span for the outer async
function should not "cover" the async body, which is actually executed
in a separate "closure" MIR.

Author: richkadel

compiler/rustc_mir/src/util/generic_graphviz.rs

@@ -116,9 +116,13 @@ impl<
 
         write!(w, r#"<table border="0" cellborder="1" cellspacing="0">"#)?;
 
-        // FIXME(richkadel): Need generic way to know if node header should have a different color
+        // FIXME(richkadel): If/when migrating the MIR graphviz to this generic implementation,
+        // we need generic way to know if node header should have a different color. For example,
+        // for MIR:
+        //
         // let (blk, bgcolor) = if data.is_cleanup {
-        //    (format!("{:?} (cleanup)", node), "lightblue")
+        //     let color = if dark_mode { "royalblue" } else { "lightblue" };
+        //     (format!("{:?} (cleanup)", node), color)
         // } else {
         //     let color = if dark_mode { "dimgray" } else { "gray" };
         //     (format!("{:?}", node), color)

src/doc/unstable-book/src/compiler-flags/source-based-code-coverage.md

@@ -1,8 +1,6 @@
 # `source-based-code-coverage`
 
-The feature request for this feature is: [#34701]
-
-The Major Change Proposal (MCP) for this feature is: [#278](https://github.com/rust-lang/compiler-team/issues/278)
+The tracking issue for this feature is: [#79121](https://github.com/rust-lang/rust/issues/79121).
 
 ------------------------
 

src/test/run-make-fulldeps/coverage-reports-base/Makefile

@@ -54,6 +54,9 @@ endif
 %: $(SOURCEDIR)/%.rs
 	# Compile the test program with coverage instrumentation and generate relevant MIR.
 	$(RUSTC) $(SOURCEDIR)/$@.rs \
+			$$( grep -q '^\/\/ require-rust-edition-2018' $(SOURCEDIR)/$@.rs && \
+				echo "--edition=2018" \
+			) \
 			-Zinstrument-coverage \
 			-Clink-dead-code=$(LINK_DEAD_CODE)
 

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.abort.json

@@ -0,0 +1,59 @@
+{
+  "data": [
+    {
+      "files": [
+        {
+          "filename": "../coverage/abort.rs",
+          "summary": {
+            "functions": {
+              "count": 2,
+              "covered": 2,
+              "percent": 100
+            },
+            "instantiations": {
+              "count": 2,
+              "covered": 2,
+              "percent": 100
+            },
+            "lines": {
+              "count": 15,
+              "covered": 13,
+              "percent": 86.66666666666667
+            },
+            "regions": {
+              "count": 10,
+              "covered": 9,
+              "notcovered": 1,
+              "percent": 90
+            }
+          }
+        }
+      ],
+      "totals": {
+        "functions": {
+          "count": 2,
+          "covered": 2,
+          "percent": 100
+        },
+        "instantiations": {
+          "count": 2,
+          "covered": 2,
+          "percent": 100
+        },
+        "lines": {
+          "count": 15,
+          "covered": 13,
+          "percent": 86.66666666666667
+        },
+        "regions": {
+          "count": 10,
+          "covered": 9,
+          "notcovered": 1,
+          "percent": 90
+        }
+      }
+    }
+  ],
+  "type": "llvm.coverage.json.export",
+  "version": "2.0.1"
+}

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.assert.json

@@ -0,0 +1,59 @@
+{
+  "data": [
+    {
+      "files": [
+        {
+          "filename": "../coverage/assert.rs",
+          "summary": {
+            "functions": {
+              "count": 2,
+              "covered": 2,
+              "percent": 100
+            },
+            "instantiations": {
+              "count": 2,
+              "covered": 2,
+              "percent": 100
+            },
+            "lines": {
+              "count": 13,
+              "covered": 10,
+              "percent": 76.92307692307693
+            },
+            "regions": {
+              "count": 14,
+              "covered": 12,
+              "notcovered": 2,
+              "percent": 85.71428571428571
+            }
+          }
+        }
+      ],
+      "totals": {
+        "functions": {
+          "count": 2,
+          "covered": 2,
+          "percent": 100
+        },
+        "instantiations": {
+          "count": 2,
+          "covered": 2,
+          "percent": 100
+        },
+        "lines": {
+          "count": 13,
+          "covered": 10,
+          "percent": 76.92307692307693
+        },
+        "regions": {
+          "count": 14,
+          "covered": 12,
+          "notcovered": 2,
+          "percent": 85.71428571428571
+        }
+      }
+    }
+  ],
+  "type": "llvm.coverage.json.export",
+  "version": "2.0.1"
+}

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.async.json

@@ -0,0 +1,59 @@
+{
+  "data": [
+    {
+      "files": [
+        {
+          "filename": "../coverage/async.rs",
+          "summary": {
+            "functions": {
+              "count": 9,
+              "covered": 9,
+              "percent": 100
+            },
+            "instantiations": {
+              "count": 9,
+              "covered": 9,
+              "percent": 100
+            },
+            "lines": {
+              "count": 31,
+              "covered": 30,
+              "percent": 96.7741935483871
+            },
+            "regions": {
+              "count": 21,
+              "covered": 18,
+              "notcovered": 3,
+              "percent": 85.71428571428571
+            }
+          }
+        }
+      ],
+      "totals": {
+        "functions": {
+          "count": 9,
+          "covered": 9,
+          "percent": 100
+        },
+        "instantiations": {
+          "count": 9,
+          "covered": 9,
+          "percent": 100
+        },
+        "lines": {
+          "count": 31,
+          "covered": 30,
+          "percent": 96.7741935483871
+        },
+        "regions": {
+          "count": 21,
+          "covered": 18,
+          "notcovered": 3,
+          "percent": 85.71428571428571
+        }
+      }
+    }
+  ],
+  "type": "llvm.coverage.json.export",
+  "version": "2.0.1"
+}

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.conditions.json

@@ -16,15 +16,15 @@
               "percent": 100
             },
             "lines": {
-              "count": 49,
-              "covered": 23,
-              "percent": 46.93877551020408
+              "count": 64,
+              "covered": 33,
+              "percent": 51.5625
             },
             "regions": {
-              "count": 69,
-              "covered": 18,
-              "notcovered": 51,
-              "percent": 26.08695652173913
+              "count": 88,
+              "covered": 25,
+              "notcovered": 63,
+              "percent": 28.40909090909091
             }
           }
         }
@@ -41,15 +41,15 @@
           "percent": 100
         },
         "lines": {
-          "count": 49,
-          "covered": 23,
-          "percent": 46.93877551020408
+          "count": 64,
+          "covered": 33,
+          "percent": 51.5625
         },
         "regions": {
-          "count": 69,
-          "covered": 18,
-          "notcovered": 51,
-          "percent": 26.08695652173913
+          "count": 88,
+          "covered": 25,
+          "notcovered": 63,
+          "percent": 28.40909090909091
         }
       }
     }

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.inner_items.json

@@ -16,15 +16,15 @@
               "percent": 100
             },
             "lines": {
-              "count": 26,
-              "covered": 26,
+              "count": 27,
+              "covered": 27,
               "percent": 100
             },
             "regions": {
-              "count": 15,
-              "covered": 13,
+              "count": 11,
+              "covered": 9,
               "notcovered": 2,
-              "percent": 86.66666666666667
+              "percent": 81.81818181818183
             }
           }
         }
@@ -41,15 +41,15 @@
           "percent": 100
         },
         "lines": {
-          "count": 26,
-          "covered": 26,
+          "count": 27,
+          "covered": 27,
           "percent": 100
         },
         "regions": {
-          "count": 15,
-          "covered": 13,
+          "count": 11,
+          "covered": 9,
           "notcovered": 2,
-          "percent": 86.66666666666667
+          "percent": 81.81818181818183
         }
       }
     }

src/test/run-make-fulldeps/coverage-reports-base/expected_export_coverage.nested_loops.json

@@ -16,15 +16,15 @@
               "percent": 100
             },
             "lines": {
-              "count": 21,
+              "count": 22,
               "covered": 16,
-              "percent": 76.19047619047619
+              "percent": 72.72727272727273
             },
             "regions": {
-              "count": 18,
-              "covered": 14,
+              "count": 17,
+              "covered": 13,
               "notcovered": 4,
-              "percent": 77.77777777777779
+              "percent": 76.47058823529412
             }
           }
         }
@@ -41,15 +41,15 @@
           "percent": 100
         },
         "lines": {
-          "count": 21,
+          "count": 22,
           "covered": 16,
-          "percent": 76.19047619047619
+          "percent": 72.72727272727273
         },
         "regions": {
-          "count": 18,
-          "covered": 14,
+          "count": 17,
+          "covered": 13,
           "notcovered": 4,
-          "percent": 77.77777777777779
+          "percent": 76.47058823529412
         }
       }
     }