Make it work

Author: keith

rust/private/repository_utils.bzl

@@ -137,6 +137,35 @@ def BUILD_for_clippy(target_triple):
     system = triple_to_system(target_triple)
     return _build_file_for_clippy_template.format(binary_ext = system_to_binary_ext(system))
 
+_build_file_for_llvm_tools = """\
+filegroup(
+    name = "llvm_cov_bin",
+    srcs = ["lib/rustlib/{target_triple}/bin/llvm-cov{binary_ext}"],
+    visibility = ["//visibility:public"],
+)
+
+filegroup(
+    name = "llvm_profdata_bin",
+    srcs = ["lib/rustlib/{target_triple}/bin/llvm-profdata{binary_ext}"],
+    visibility = ["//visibility:public"],
+)
+"""
+
+def BUILD_for_llvm_tools(target_triple):
+    """Emits a BUILD file the llvm-tools binaries.
+
+    Args:
+        target_triple (str): The triple of the target platform
+
+    Returns:
+        str: The contents of a BUILD file
+    """
+    system = triple_to_system(target_triple)
+    return _build_file_for_llvm_tools.format(
+        binary_ext = system_to_binary_ext(system),
+        target_triple = target_triple,
+    )
+
 _build_file_for_stdlib_template = """\
 load("@rules_rust//rust:toolchain.bzl", "rust_stdlib_filegroup")
 
@@ -189,6 +218,8 @@ rust_toolchain(
     rustfmt = {rustfmt_label},
     cargo = "@{workspace_name}//:cargo",
     clippy_driver = "@{workspace_name}//:clippy_driver_bin",
+    llvm_cov = {llvm_cov_label},
+    llvm_profdata = {llvm_profdata_label},
     rustc_lib = "@{workspace_name}//:rustc_lib",
     rustc_srcs = {rustc_srcs},
     binary_ext = "{binary_ext}",
@@ -211,6 +242,7 @@ def BUILD_for_rust_toolchain(
         include_rustc_srcs,
         default_edition,
         include_rustfmt,
+        include_llvm_tools,
         stdlib_linkflags = None):
     """Emits a toolchain declaration to match an existing compiler and stdlib.
 
@@ -222,6 +254,7 @@ def BUILD_for_rust_toolchain(
         include_rustc_srcs (bool, optional): Whether to download rustc's src code. This is required in order to use rust-analyzer support. Defaults to False.
         default_edition (str): Default Rust edition.
         include_rustfmt (bool): Whether rustfmt is present in the toolchain.
+        include_llvm_tools (bool): Whether llvm-tools are present in the toolchain.
         stdlib_linkflags (list, optional): Overriden flags needed for linking to rust
                                            stdlib, akin to BAZEL_LINKLIBS. Defaults to
                                            None.
@@ -240,6 +273,11 @@ def BUILD_for_rust_toolchain(
     rustfmt_label = "None"
     if include_rustfmt:
         rustfmt_label = "\"@{workspace_name}//:rustfmt_bin\"".format(workspace_name = workspace_name)
+    llvm_cov_label = "None"
+    llvm_profdata_label = "None"
+    if include_llvm_tools:
+        llvm_cov_label = "\"@{workspace_name}//:llvm_cov_bin\"".format(workspace_name = workspace_name)
+        llvm_profdata_label = "\"@{workspace_name}//:llvm_profdata_bin\"".format(workspace_name = workspace_name)
 
     return _build_file_for_rust_toolchain_template.format(
         toolchain_name = name,
@@ -254,6 +292,8 @@ def BUILD_for_rust_toolchain(
         exec_triple = exec_triple,
         target_triple = target_triple,
         rustfmt_label = rustfmt_label,
+        llvm_cov_label = llvm_cov_label,
+        llvm_profdata_label = llvm_profdata_label,
     )
 
 _build_file_for_toolchain_template = """\
@@ -369,12 +409,13 @@ filegroup(
 )""",
     )
 
-def load_rust_stdlib(ctx, target_triple):
+def load_rust_stdlib(ctx, target_triple, include_llvm_tools):
     """Loads a rust standard library and yields corresponding BUILD for it
 
     Args:
         ctx (repository_ctx): A repository_ctx.
         target_triple (str): The rust-style target triple of the tool
+        include_llvm_tools (bool): Whether to include LLVM tools in the toolchain
 
     Returns:
         str: The BUILD file contents for this stdlib, and a toolchain decl to match
@@ -408,6 +449,7 @@ def load_rust_stdlib(ctx, target_triple):
         workspace_name = ctx.attr.name,
         default_edition = ctx.attr.edition,
         include_rustfmt = not (not ctx.attr.rustfmt_version),
+        include_llvm_tools = include_llvm_tools,
     )
 
     return stdlib_build_file + toolchain_build_file
@@ -449,6 +491,8 @@ def load_llvm_tools(ctx, target_triple):
         version = ctx.attr.version,
     )
 
+    return BUILD_for_llvm_tools(target_triple)
+
 def check_version_valid(version, iso_date, param_prefix = ""):
     """Verifies that the provided rust version and iso_date make sense.
 

rust/private/rust.bzl

@@ -410,6 +410,8 @@ def _rust_test_common(ctx, toolchain, output):
         getattr(ctx.attr, "env", {}),
         data,
     )
+    env["RUST_LLVM_COV"] = toolchain.llvm_cov.path
+    env["RUST_LLVM_PROFDATA"] = toolchain.llvm_profdata.path
     providers.append(testing.TestEnvironment(env))
 
     return providers

rust/private/rustc.bzl

@@ -792,7 +792,7 @@ def construct_arguments(
         rustc_flags.add("proc_macro")
 
     if ctx.configuration.coverage_enabled:
-        rustc_flags.add("-Cinstrument-coverage")
+        rustc_flags.add("--codegen=instrument-coverage")
 
     # Make bin crate data deps available to tests.
     for data in getattr(attr, "data", []):
@@ -979,8 +979,12 @@ 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]
+
     runfiles = ctx.runfiles(
-        files = getattr(ctx.files, "data", []),
+        files = getattr(ctx.files, "data", []) + coverage_runfiles,
         collect_data = True,
     )
 

rust/repositories.bzl

@@ -163,11 +163,12 @@ def _rust_toolchain_repository_impl(ctx):
         build_components.append(load_rustfmt(ctx))
 
     # Rust 1.45.0 and nightly builds after 2020-05-22 need the llvm-tools gzip to get the libLLVM dylib
-    if ctx.attr.version >= "1.45.0" or (ctx.attr.version == "nightly" and ctx.attr.iso_date > "2020-05-22"):
-        load_llvm_tools(ctx, ctx.attr.exec_triple)
+    include_llvm_tools = ctx.attr.version >= "1.45.0" or (ctx.attr.version == "nightly" and ctx.attr.iso_date > "2020-05-22")
+    if include_llvm_tools:
+        build_components.append(load_llvm_tools(ctx, ctx.attr.exec_triple))
 
     for target_triple in [ctx.attr.exec_triple] + ctx.attr.extra_target_triples:
-        build_components.append(load_rust_stdlib(ctx, target_triple))
+        build_components.append(load_rust_stdlib(ctx, target_triple, include_llvm_tools))
 
         # extra_target_triples contains targets such as wasm, which don't have rustc_dev components
         if ctx.attr.dev_components and target_triple not in ctx.attr.extra_target_triples:

rust/toolchain.bzl

@@ -465,6 +465,8 @@ def _rust_toolchain_impl(ctx):
         dylib_ext = ctx.attr.dylib_ext,
         exec_triple = ctx.attr.exec_triple,
         libstd_and_allocator_ccinfo = _make_libstd_and_allocator_ccinfo(ctx, rust_std, ctx.attr.allocator_library),
+        llvm_cov = ctx.file.llvm_cov,
+        llvm_profdata = ctx.file.llvm_profdata,
         os = ctx.attr.os,
         rust_doc = sysroot.rustdoc,
         rust_lib = sysroot.rust_std,  # `rust_lib` is deprecated and only exists for legacy support.
@@ -535,6 +537,16 @@ rust_toolchain = rule(
             ),
             mandatory = True,
         ),
+        "llvm_cov": attr.label(
+            doc = "The location of the `llvm-cov` binary. Can be a direct source or a filegroup containing one item.",
+            allow_single_file = True,
+            cfg = "exec",
+        ),
+        "llvm_profdata": attr.label(
+            doc = "The location of the `llvm-profdata` binary. Can be a direct source or a filegroup containing one item.",
+            allow_single_file = True,
+            cfg = "exec",
+        ),
         "llvm_tools": attr.label(
             doc = "LLVM tools that are shipped with the Rust toolchain.",
             allow_files = True,

util/collect_coverage.sh

@@ -1,33 +1,24 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -euo pipefail
-set -x
 
-echo here!
-
-# export LLVM_PROFILE_FILE="${COVERAGE_DIR}/%h-%p-%m.profraw"
-output_file=$COVERAGE_DIR/_cc_coverage.dat
-
-/Users/ksmiley/dev/rules_rust/examples/bazel-examples/external/rust_darwin_aarch64/lib/rustlib/aarch64-apple-darwin/bin/llvm-profdata \
-  merge --sparse \
-  "${COVERAGE_DIR}"/*.profraw \
-  -output "${output_file}.data"
-
-# object_param=""
-# while read -r line; do
-#   if [[ ${line: -24} == "runtime_objects_list.txt" ]]; then
-#     while read -r line_runtime_object; do
-#       if [[ -e "${RUNFILES_DIR}/${TEST_WORKSPACE}/${line_runtime_object}" ]]; then
-#         object_param+=" -object ${RUNFILES_DIR}/${TEST_WORKSPACE}/${line_runtime_object}"
-#       fi
-#     done < "${line}"
-#   fi
-# done < "${COVERAGE_MANIFEST}"
-
-
-# /Users/ksmiley/dev/rules_rust/examples/bazel-examples/external/rust_darwin_aarch64/lib/rustlib/aarch64-apple-darwin/bin/llvm-cov export -instr-profile "${output_file}.data" -format=lcov \
-#   -ignore-filename-regex='.*external/.+' \
-#   -ignore-filename-regex='/tmp/.+' \
-#   ${object_param} | sed 's#/proc/self/cwd/##' > "${output_file}"
-
-# exit 1
+if [[ -n "${VERBOSE_COVERAGE:-}" ]]; then
+  set -x
+fi
+
+readonly profdata_file=$COVERAGE_DIR/coverage.profdata
+
+"$RUNFILES_DIR/$TEST_WORKSPACE/$RUST_LLVM_PROFDATA" \
+  merge \
+  --sparse "$COVERAGE_DIR"/*.profraw \
+  -output "$profdata_file"
+
+"$RUNFILES_DIR/$TEST_WORKSPACE/$RUST_LLVM_COV" \
+  export \
+  -format=lcov \
+  -instr-profile "$profdata_file" \
+  -ignore-filename-regex='.*external/.+' \
+  -ignore-filename-regex='/tmp/.+' \
+  -path-equivalence="$ROOT",. \
+  "$RUNFILES_DIR/$TEST_WORKSPACE/$TEST_BINARY" \
+  | sed 's#/proc/self/cwd/##' > "$COVERAGE_OUTPUT_FILE"