Test linking pthread_trace as a library too

test/BUILD

@@ -19,8 +19,8 @@ cc_test(
 # The best we have for now is just running one of the benchmarks that use pthreads with tracing,
 # and verifying it doesn't crash and we see expected pthread_trace output.
 sh_test(
-    name = "trace_thread_benchmark",
-    srcs = ["trace_test.sh"],
+    name = "ld_preload_test_thread_benchmark",
+    srcs = ["ld_preload_test.sh"],
     data = [
         ":thread_benchmark",
         "//:pthread_trace.so",
@@ -41,6 +41,28 @@ cc_test(
     size = "small",
 )
 
+cc_test(
+    name = "traced_thread_benchmark",
+    srcs = ["thread_benchmark.cc"],
+    deps = [
+        "//:pthread_trace",
+        "@google_benchmark//:benchmark_main",
+    ],
+    args = ["--benchmark_min_time=1x"],
+    size = "small",
+)
+
+sh_test(
+    name = "linked_test_thread_benchmark",
+    srcs = ["linked_test.sh"],
+    data = [":traced_thread_benchmark"],
+    args = [
+        "$(location :traced_thread_benchmark)",
+        "--benchmark_min_time=1x",
+    ],
+    size = "small",
+)
+
 cc_test(
     name = "proto_benchmark",
     srcs = ["proto_benchmark.cc"],

test/linked_test.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+target="$1"
+
+shift
+
+fail() { rc=$?; (( $# )) && printf '%s\n' "$*" >&2; exit $(( rc == 0 ? 1 : rc )); }
+
+trace=$(mktemp)
+
+exec 5>&1
+output=$(PTHREAD_TRACE_BUFFER_SIZE_KB=1 PTHREAD_TRACE_PATH=$trace "$target" "$@" 2>&1 | tee >(cat - >&5))
+
+echo "$output" | grep "pthread_trace: Recorded.*KB trace" > /dev/null || fail "Did not find pthread_trace report in output"