Add -Z profile-emit=<path> for Gcov gcda output.

Adds a -Z flag to control the file path that the Gcov gcda output is
written to during runtime. This flag expects a path and filename, e.g.
-Z profile-emit=gcov/out/lib.gcda.

This works similar to GCC/Clang's -fprofile-dir flag which allows
control over the output path for gcda coverage files.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs
index 0cce0b25e58..333eb805221 100644
--- a/src/librustc_codegen_llvm/debuginfo/metadata.rs
+++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs
@@ -959,16 +959,16 @@ pub fn compile_unit_metadata(
         if tcx.sess.opts.debugging_opts.profile {
             let cu_desc_metadata =
                 llvm::LLVMRustMetadataAsValue(debug_context.llcontext, unit_metadata);
+            let default_gcda_path = &tcx.output_filenames(LOCAL_CRATE).with_extension("gcda");
+            let gcda_path =
+                tcx.sess.opts.debugging_opts.profile_emit.as_ref().unwrap_or(default_gcda_path);
 
             let gcov_cu_info = [
                 path_to_mdstring(
                     debug_context.llcontext,
                     &tcx.output_filenames(LOCAL_CRATE).with_extension("gcno"),
                 ),
-                path_to_mdstring(
-                    debug_context.llcontext,
-                    &tcx.output_filenames(LOCAL_CRATE).with_extension("gcda"),
-                ),
+                path_to_mdstring(debug_context.llcontext, &gcda_path),
                 cu_desc_metadata,
             ];
             let gcov_metadata = llvm::LLVMMDNodeInContext(