chore: split platform code per translation unit

BUILD.bazel

@@ -28,7 +28,6 @@ cc_library(
       "src/datadog/logger.cpp",
       "src/datadog/msgpack.cpp",
       "src/datadog/parse_util.cpp",
-      "src/datadog/platform_util.cpp",
       "src/datadog/propagation_style.cpp",
       "src/datadog/random.cpp",
       "src/datadog/rate.cpp",
@@ -84,7 +83,20 @@ cc_library(
       "src/datadog/threaded_event_scheduler.h",
       "src/datadog/trace_sampler.h",
       "src/datadog/w3c_propagation.h",
+] + select({
+    "@platforms//os:windows": [
+        "src/datadog/platform_util_windows.cpp",
     ],
+    "@platforms//os:linux": [
+        "src/datadog/platform_util_unix.cpp",
+    ],
+    "@platforms//os:macos": [
+        "src/datadog/platform_util_darwin.cpp",
+    ],
+    "//conditions:default": [
+        "src/datadog/platform_util_unknown.cpp",
+    ],
+}),
     hdrs = [
       "include/datadog/baggage.h",
       "include/datadog/cerr_logger.h",

CMakeLists.txt

@@ -184,7 +184,6 @@ target_sources(dd-trace-cpp-objects
     src/datadog/logger.cpp
     src/datadog/msgpack.cpp
     src/datadog/parse_util.cpp
-    src/datadog/platform_util.cpp
     src/datadog/propagation_style.cpp
     src/datadog/random.cpp
     src/datadog/rate.cpp
@@ -212,6 +211,16 @@ target_sources(dd-trace-cpp-objects
     src/datadog/w3c_propagation.cpp
 )
 
+if (WIN32)
+  target_sources(dd-trace-cpp-objects PRIVATE src/datadog/platform_util_windows.cpp)
+elseif (APPLE)
+  target_sources(dd-trace-cpp-objects PRIVATE src/datadog/platform_util_darwin.cpp)
+elseif (UNIX)
+  target_sources(dd-trace-cpp-objects PRIVATE src/datadog/platform_util_unix.cpp)
+else ()
+  target_sources(dd-trace-cpp-objects PRIVATE src/datadog/platform_util_unknown.cpp)
+endif ()
+
 target_include_directories(dd-trace-cpp-objects
   PRIVATE
     ${CMAKE_CURRENT_SOURCE_DIR}/src/datadog

MODULE.bazel

@@ -1,8 +1,12 @@
 module(
     name = "dd-trace-cpp",
-    version = "",
+    version = "2.0.0",
 )
 
+bazel_dep(
+    name = "platforms",
+    version = "0.0.11"
+)
 bazel_dep(
     name = "bazel_skylib",
     version = "1.2.1",

WORKSPACE

@@ -26,3 +26,9 @@ http_archive(
   urls = ["https://github.com/bazelbuild/bazel-skylib/releases/download/1.2.1/bazel-skylib-1.2.1.tar.gz"],
   sha256 = "f7be3474d42aae265405a592bb7da8e171919d74c16f082a5457840f06054728",
 )
+
+http_archive(
+  name = "platforms",
+  urls = ["https://github.com/bazelbuild/platforms/releases/download/0.0.8/platforms-0.0.8.tar.gz"],
+  sha256 = "8150406605389ececb6da07cbcb509d5637a3ab9a24bc69b1101531367d89d74",
+)

src/datadog/platform_util.h

@@ -6,6 +6,19 @@
 #include <datadog/string_view.h>
 
 #include <string>
+#include <vector>
+
+// clang-format off
+#if defined(__x86_64__) || defined(_M_X64)
+#  define DD_SDK_CPU_ARCH "x86_64"
+#elif defined(i386) || defined(__i386__) || defined(__i386) || defined(_M_IX86)
+#  define DD_SDK_CPU_ARCH "x86"
+#elif defined(__aarch64__) || defined(_M_ARM64)
+#  define DD_SDK_CPU_ARCH "arm64"
+#else
+#  define DD_SDK_CPU_ARCH "unknown"
+#endif
+// clang-format on
 
 namespace datadog {
 namespace tracing {

src/datadog/platform_util_darwin.cpp

@@ -0,0 +1,147 @@
+#include <pthread.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <unistd.h>
+
+#include <cassert>
+#include <cstdint>
+#include <fstream>
+#include <regex>
+
+#include "platform_util.h"
+
+#define DD_SDK_OS "Darwin"
+#define DD_SDK_KERNEL "Darwin"
+
+namespace datadog {
+namespace tracing {
+namespace {
+
+std::string get_os_version() {
+  char os_version[20] = "";
+  size_t len = sizeof(os_version);
+
+  sysctlbyname("kern.osproductversion", os_version, &len, NULL, 0);
+  return os_version;
+}
+
+HostInfo _get_host_info() {
+  HostInfo res;
+
+  struct utsname buffer;
+  if (uname(&buffer) != 0) {
+    return res;
+  }
+
+  res.os = DD_SDK_OS;
+  res.os_version = get_os_version();
+  res.hostname = buffer.nodename;
+  res.cpu_architecture = DD_SDK_CPU_ARCH;
+  res.kernel_name = DD_SDK_KERNEL;
+  res.kernel_version = buffer.version;
+  res.kernel_release = buffer.release;
+
+  return res;
+}
+
+}  // namespace
+
+HostInfo get_host_info() {
+  static const HostInfo host_info = _get_host_info();
+  return host_info;
+}
+
+std::string get_hostname() { return get_host_info().hostname; }
+
+int get_process_id() { return ::getpid(); }
+
+std::string get_process_name() {
+  const char* process_name = getprogname();
+  return (process_name != nullptr) ? process_name : "unknown-service";
+}
+
+int at_fork_in_child(void (*on_fork)()) {
+  // https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_atfork.html
+  return pthread_atfork(/*before fork*/ nullptr, /*in parent*/ nullptr,
+                        /*in child*/ on_fork);
+}
+
+InMemoryFile::InMemoryFile(void* handle) : handle_(handle) {}
+
+InMemoryFile::~InMemoryFile() {}
+
+InMemoryFile::InMemoryFile(InMemoryFile&& rhs) {
+  std::swap(rhs.handle_, handle_);
+}
+
+InMemoryFile& InMemoryFile::operator=(InMemoryFile&& rhs) {
+  std::swap(handle_, rhs.handle_);
+  return *this;
+}
+
+bool InMemoryFile::write_then_seal(const std::string&) { return false; }
+Expected<InMemoryFile> InMemoryFile::make(StringView) {
+  return Error{Error::Code::NOT_IMPLEMENTED, "In-memory file not implemented"};
+}
+
+namespace container {
+
+Optional<std::string> find_container_id(std::istream& source) {
+  std::string line;
+
+  // Look for Docker container IDs in the basic format: `docker-<uuid>.scope`.
+  constexpr std::string_view docker_str = "docker-";
+
+  while (std::getline(source, line)) {
+    // Example:
+    // `0::/system.slice/docker-abcdef0123456789abcdef0123456789.scope`
+    if (auto beg = line.find(docker_str); beg != std::string::npos) {
+      beg += docker_str.size();
+      auto end = line.find(".scope", beg);
+      if (end == std::string::npos || end - beg <= 0) {
+        continue;
+      }
+
+      auto container_id = line.substr(beg, end - beg);
+      return container_id;
+    }
+  }
+
+  // Reset the stream to the beginning.
+  source.clear();
+  source.seekg(0);
+
+  // Perform a second pass using a regular expression for matching container IDs
+  // in a Fargate environment. This two-step approach is used because STL
+  // `regex` is relatively slow, so we avoid using it unless necessary.
+  static const std::string uuid_regex_str =
+      "[0-9a-f]{8}[-_][0-9a-f]{4}[-_][0-9a-f]{4}[-_][0-9a-f]{4}[-_][0-9a-f]{12}"
+      "|(?:[0-9a-f]{8}(?:-[0-9a-f]{4}){4}$)";
+  static const std::string container_regex_str = "[0-9a-f]{64}";
+  static const std::string task_regex_str = "[0-9a-f]{32}-\\d+";
+  static const std::regex path_reg("(?:.+)?(" + uuid_regex_str + "|" +
+                                   container_regex_str + "|" + task_regex_str +
+                                   ")(?:\\.scope)?$");
+
+  while (std::getline(source, line)) {
+    // Example:
+    // `0::/system.slice/docker-abcdef0123456789abcdef0123456789.scope`
+    std::smatch match;
+    if (std::regex_match(line, match, path_reg) && match.size() == 2) {
+      assert(match.ready());
+      assert(match.size() == 2);
+
+      return match.str(1);
+    }
+  }
+
+  return nullopt;
+}
+
+Optional<ContainerID> get_id() { return nullopt; }
+
+}  // namespace container
+
+}  // namespace tracing
+}  // namespace datadog