Add libLLVM to coverage runfiles (#3546)

Fixes #2760

Author: mortenmj

rust/private/repository_utils.bzl

@@ -172,6 +172,15 @@ def BUILD_for_clippy(target_triple):
     )
 
 _build_file_for_llvm_tools = """\
+filegroup(
+    name = "llvm_lib",
+    srcs = glob(
+      ["lib/rustlib/{target_triple}/lib/libLLVM*.so*"],
+      allow_empty = True,
+    ),
+    visibility = ["//visibility:public"],
+)
+
 filegroup(
     name = "llvm_cov_bin",
     srcs = ["lib/rustlib/{target_triple}/bin/llvm-cov{binary_ext}"],
@@ -255,6 +264,7 @@ rust_toolchain(
     cargo_clippy = "//:cargo_clippy_bin",
     llvm_cov = {llvm_cov_label},
     llvm_profdata = {llvm_profdata_label},
+    llvm_lib = {llvm_lib_label},
     rustc_lib = "//:rustc_lib",
     allocator_library = {allocator_library},
     global_allocator_library = {global_allocator_library},
@@ -322,9 +332,11 @@ def BUILD_for_rust_toolchain(
         rustfmt_label = "\"//:rustfmt_bin\""
     llvm_cov_label = "None"
     llvm_profdata_label = "None"
+    llvm_lib_label = "None"
     if include_llvm_tools:
         llvm_cov_label = "\"//:llvm_cov_bin\""
         llvm_profdata_label = "\"//:llvm_profdata_bin\""
+        llvm_lib_label = "\"//:llvm_lib\""
     allocator_library_label = "None"
     if allocator_library:
         allocator_library_label = "\"{allocator_library}\"".format(allocator_library = allocator_library)
@@ -346,6 +358,7 @@ def BUILD_for_rust_toolchain(
         rustfmt_label = rustfmt_label,
         llvm_cov_label = llvm_cov_label,
         llvm_profdata_label = llvm_profdata_label,
+        llvm_lib_label = llvm_lib_label,
         extra_rustc_flags = extra_rustc_flags,
         extra_exec_rustc_flags = extra_exec_rustc_flags,
         opt_level = opt_level,

rust/private/rustc.bzl

@@ -1525,7 +1525,7 @@ def rustc_compile_action(
 
     coverage_runfiles = []
     if toolchain.llvm_cov and ctx.configuration.coverage_enabled and crate_info.is_test:
-        coverage_runfiles = [toolchain.llvm_cov, toolchain.llvm_profdata]
+        coverage_runfiles = [toolchain.llvm_cov, toolchain.llvm_profdata] + toolchain.llvm_lib
 
     experimental_use_coverage_metadata_files = toolchain._experimental_use_coverage_metadata_files
 

rust/toolchain.bzl

@@ -716,6 +716,7 @@ def _rust_toolchain_impl(ctx):
         make_libstd_and_allocator_ccinfo = make_ccinfo,
         llvm_cov = ctx.file.llvm_cov,
         llvm_profdata = ctx.file.llvm_profdata,
+        llvm_lib = ctx.files.llvm_lib,
         lto = lto,
         make_variables = make_variable_info,
         rust_doc = sysroot.rustdoc,
@@ -863,6 +864,11 @@ rust_toolchain = rule(
             allow_single_file = True,
             cfg = "exec",
         ),
+        "llvm_lib": attr.label(
+            doc = "The location of the `libLLVM` shared object files. If `llvm_cov` is None, this can be None as well and rust code is not instrumented for coverage.",
+            allow_files = True,
+            cfg = "exec",
+        ),
         "llvm_tools": attr.label(
             doc = "LLVM tools that are shipped with the Rust toolchain.",
             allow_files = True,