chore(crashtracker): add required backend tags (#10199)

This adds two new tags to the crashtracker. These tags will not be
required in an upcoming version of libdatadog, but that version doesn't
exist yet, so here we are.

There's no need to document anything in a changelog since this feature
isn't customer-impacting. It just makes it easier for us to build
dashboards on the backend. :)

[PROF-10357]

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

(cherry picked from commit a657198)

ddtrace/internal/datadog/profiling/dd_wrapper/include/constants.hpp

@@ -23,3 +23,7 @@ constexpr std::string_view g_language_name = "python";
 
 // Name of the library
 constexpr std::string_view g_library_name = "dd-trace-py";
+
+// These are default settings for crashtracker tags.  These will be moved internally to crashtracker in the near future.
+constexpr std::string_view g_crashtracker_is_crash = "true";
+constexpr std::string_view g_crashtracker_severity = "crash";

ddtrace/internal/datadog/profiling/dd_wrapper/include/libdatadog_helpers.hpp

@@ -28,7 +28,9 @@ namespace Datadog {
     X(runtime_id, "runtime-id")                                                                                        \
     X(profiler_version, "profiler_version")                                                                            \
     X(library_version, "library_version")                                                                              \
-    X(profile_seq, "profile_seq")
+    X(profile_seq, "profile_seq")                                                                                      \
+    X(is_crash, "is_crash")                                                                                            \
+    X(severity, "severity")
 
 // Here there are two columns because the Datadog backend expects these labels
 // to have spaces in the names.

ddtrace/internal/datadog/profiling/dd_wrapper/src/crashtracker.cpp

@@ -155,6 +155,8 @@ Datadog::Crashtracker::get_tags()
         { ExportTagKey::runtime, runtime },
         { ExportTagKey::runtime_version, runtime_version },
         { ExportTagKey::library_version, library_version },
+        { ExportTagKey::is_crash, g_crashtracker_is_crash },
+        { ExportTagKey::severity, g_crashtracker_severity },
     };
 
     // Add system tags

tests/internal/crashtracker/test_crashtracker.py

@@ -414,6 +414,45 @@ def test_crashtracker_auto_disabled(run_python_code_in_subprocess):
     assert not conn
 
 
+@pytest.mark.skipif(not sys.platform.startswith("linux"), reason="Linux only")
+@pytest.mark.subprocess()
+def test_crashtracker_tags_required():
+    # Tests tag ingestion in the core API
+    import ctypes
+    import os
+
+    import tests.internal.crashtracker.utils as utils
+
+    port, sock = utils.crashtracker_receiver_bind()
+    assert port
+    assert sock
+
+    pid = os.fork()
+    if pid == 0:
+        assert utils.start_crashtracker(port)
+        stdout_msg, stderr_msg = utils.read_files(["stdout.log", "stderr.log"])
+        assert not stdout_msg
+        assert not stderr_msg
+
+        ctypes.string_at(0)
+        exit(-1)
+
+    conn = utils.listen_get_conn(sock)
+    assert conn
+    data = utils.conn_to_bytes(conn)
+    conn.close()
+    assert b"string_at" in data
+
+    # Now check for the tags
+    tags = {
+        "is_crash": "true",
+        "severity": "crash",
+    }
+    for k, v in tags.items():
+        assert k.encode() in data, k
+        assert v.encode() in data, v
+
+
 @pytest.mark.skipif(not sys.platform.startswith("linux"), reason="Linux only")
 def test_crashtracker_user_tags_envvar(run_python_code_in_subprocess):
     # Setup the listening socket before we open ddtrace