coverage: Skip spans that can't be un-expanded back to the function body

When we extract coverage spans from MIR, we try to "un-expand" them back to
spans that are inside the function's body span.

In cases where that doesn't succeed, the current code just swaps in the entire
body span instead. But that tends to result in coverage spans that are
completely unrelated to the control flow of the affected code, so it's better
to just discard those spans.

6 files changed, 23 insertions, 23 deletions

diff --git a/tests/coverage/async.cov-map b/tests/coverage/async.cov-map
index 857e0a536a7..e4354a1af87 100644
--- a/tests/coverage/async.cov-map
+++ b/tests/coverage/async.cov-map
@@ -74,28 +74,28 @@ Number of file 0 mappings: 6
     = ((c0 + c1) - c1)
 
 Function name: async::executor::block_on::VTABLE::{closure#0}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 72, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 72, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 114, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 114, 17) to (start + 0, 49)
 
 Function name: async::executor::block_on::VTABLE::{closure#1}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 73, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 73, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 115, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 115, 17) to (start + 0, 49)
 
 Function name: async::executor::block_on::VTABLE::{closure#2}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 74, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 74, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 116, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 116, 17) to (start + 0, 49)
 
 Function name: async::executor::block_on::VTABLE::{closure#3}
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 75, 11, 00, 13]
diff --git a/tests/coverage/async2.cov-map b/tests/coverage/async2.cov-map
index cc7aed9aee3..23f26ee4e5f 100644
--- a/tests/coverage/async2.cov-map
+++ b/tests/coverage/async2.cov-map
@@ -78,28 +78,28 @@ Number of file 0 mappings: 6
     = ((c0 + c1) - c1)
 
 Function name: async2::executor::block_on::VTABLE::{closure#0}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 2b, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 2b, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 43, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 43, 17) to (start + 0, 49)
 
 Function name: async2::executor::block_on::VTABLE::{closure#1}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 2c, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 2c, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 44, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 44, 17) to (start + 0, 49)
 
 Function name: async2::executor::block_on::VTABLE::{closure#2}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 2d, 11, 00, 33]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 2d, 11, 00, 31]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 45, 17) to (start + 0, 51)
+- Code(Counter(0)) at (prev + 45, 17) to (start + 0, 49)
 
 Function name: async2::executor::block_on::VTABLE::{closure#3}
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 2e, 11, 00, 13]
diff --git a/tests/coverage/inline.cov-map b/tests/coverage/inline.cov-map
index 72b10fd0cc2..001c333ae6d 100644
--- a/tests/coverage/inline.cov-map
+++ b/tests/coverage/inline.cov-map
@@ -15,12 +15,12 @@ Number of file 0 mappings: 5
     = ((c0 + c1) - c1)
 
 Function name: inline::error
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 31, 01, 02, 02]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 31, 01, 01, 14]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 49, 1) to (start + 2, 2)
+- Code(Counter(0)) at (prev + 49, 1) to (start + 1, 20)
 
 Function name: inline::length::<char>
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 1e, 01, 02, 02]
diff --git a/tests/coverage/inline.coverage b/tests/coverage/inline.coverage
index 6efd9a0830b..68a2e408306 100644
--- a/tests/coverage/inline.coverage
+++ b/tests/coverage/inline.coverage
@@ -50,5 +50,5 @@
    LL|       |#[inline(always)]
    LL|      0|fn error() {
    LL|      0|    panic!("error");
-   LL|      0|}
+   LL|       |}
 
diff --git a/tests/coverage/unreachable.cov-map b/tests/coverage/unreachable.cov-map
index 495419820c1..55d124a16f5 100644
--- a/tests/coverage/unreachable.cov-map
+++ b/tests/coverage/unreachable.cov-map
@@ -1,24 +1,24 @@
 Function name: unreachable::UNREACHABLE_CLOSURE::{closure#0}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0f, 27, 00, 49]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0f, 27, 00, 47]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 15, 39) to (start + 0, 73)
+- Code(Counter(0)) at (prev + 15, 39) to (start + 0, 71)
 
 Function name: unreachable::unreachable_function
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 11, 01, 02, 02]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 11, 01, 01, 25]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 17, 1) to (start + 2, 2)
+- Code(Counter(0)) at (prev + 17, 1) to (start + 1, 37)
 
 Function name: unreachable::unreachable_intrinsic
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 16, 01, 02, 02]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 16, 01, 01, 2c]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 22, 1) to (start + 2, 2)
+- Code(Counter(0)) at (prev + 22, 1) to (start + 1, 44)
 
diff --git a/tests/coverage/unreachable.coverage b/tests/coverage/unreachable.coverage
index fa0ac9ccfa1..7015bb90aa3 100644
--- a/tests/coverage/unreachable.coverage
+++ b/tests/coverage/unreachable.coverage
@@ -16,12 +16,12 @@
    LL|       |
    LL|      0|fn unreachable_function() {
    LL|      0|    unsafe { unreachable_unchecked() }
-   LL|      0|}
+   LL|       |}
    LL|       |
    LL|       |// Use an intrinsic to more reliably trigger unreachable-propagation.
    LL|      0|fn unreachable_intrinsic() {
    LL|      0|    unsafe { std::intrinsics::unreachable() }
-   LL|      0|}
+   LL|       |}
    LL|       |
    LL|       |#[coverage(off)]
    LL|       |fn main() {