1 files changed, 36 insertions, 0 deletions
diff --git a/src/test/mir-opt/instrument_coverage.rs b/src/test/mir-opt/instrument_coverage.rs
new file mode 100644
index 000000000..a748f2c5c
--- /dev/null
+++ b/src/test/mir-opt/instrument_coverage.rs
@@ -0,0 +1,36 @@
+// Test that `-C instrument-coverage` injects Coverage statements. The Coverage Counter statements
+// are later converted into LLVM instrprof.increment intrinsics, during codegen.
+
+// needs-profiler-support
+// ignore-windows
+// compile-flags: -C instrument-coverage --remap-path-prefix={{src-base}}=/the/src
+
+// EMIT_MIR instrument_coverage.main.InstrumentCoverage.diff
+// EMIT_MIR instrument_coverage.bar.InstrumentCoverage.diff
+fn main() {
+    loop {
+        if bar() {
+            break;
+        }
+    }
+}
+
+#[inline(never)]
+fn bar() -> bool {
+    true
+}
+
+// Note that the MIR with injected coverage intrinsics includes references to source locations,
+// including the source file absolute path. Typically, MIR pretty print output with file
+// references are safe because the file prefixes are substituted with `$DIR`, but in this case
+// the file references are encoded as function arguments, with an `Operand` type representation
+// (`Slice` `Allocation` interned byte array) that cannot be normalized by simple substitution.
+//
+// The first workaround is to use the `SourceMap`-supported `--remap-path-prefix` option; however,
+// the implementation of the `--remap-path-prefix` option currently joins the new prefix and the
+// remaining source path with an OS-specific path separator (`\` on Windows). This difference still
+// shows up in the byte array representation of the path, causing Windows tests to fail to match
+// blessed results baselined with a `/` path separator.
+//
+// Since this `mir-opt` test does not have any significant platform dependencies, other than the
+// path separator differences, the final workaround is to disable testing on Windows.