mozilla · badboy · Apr 17, 2026
@@ -4,6 +4,7 @@
 
 - Go server: Add support for `labeled_boolean` metrics with static labels ([AE-1250](https://mozilla-hub.atlassian.net/browse/AE-1250))
 - BUGFIX: Go server: Serialize nil `string_list` metrics as empty arrays instead of null ([#837](https://github.com/mozilla/glean_parser/pull/837))
+- Add support to target `glean_sym` (the new experimental Glean Rust API) ([#841](https://github.com/mozilla/glean_parser/pull/841))
 
 ## 19.0.0
 

@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*-
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""
+Outputter to generate Rust code for metrics.
+"""
+
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+from . import __version__
+from . import metrics
+from . import pings
+from . import util
+from .rust import (
+    rust_datatypes_filter,
+    ctor,
+    type_name,
+    extra_type_name,
+    structure_type_name,
+    extra_keys,
+    Category,
+)
+
+
+def output_rust(
+    objs: metrics.ObjectTree, output_dir: Path, options: Optional[Dict[str, Any]] = None
+) -> None:
+    """
+    Given a tree of objects, output Rust code to `output_dir`.
+
+    :param objs: A tree of objects (metrics and pings) as returned from
+        `parser.parse_objects`.
+    :param output_dir: Path to an output directory to write to.
+    :param options: options dictionary, not currently used for Rust
+    """
+
+    if options is None:
+        options = {}
+
+    template = util.get_jinja2_template(
+        "rust_sym.jinja2",
+        filters=(
+            ("rust", rust_datatypes_filter),
+            ("snake_case", util.snake_case),
+            ("camelize", util.camelize),
+            ("type_name", type_name),
+            ("extra_type_name", extra_type_name),
+            ("structure_type_name", structure_type_name),
+            ("ctor", ctor),
+            ("extra_keys", extra_keys),
+        ),
+    )
+
+    filename = "glean_metrics.rs"
+    filepath = output_dir / filename
+    categories = []
+
+    for category_key, category_val in objs.items():
+        contains_pings = any(
+            isinstance(obj, pings.Ping) for obj in category_val.values()
+        )
+
+        cat = Category(category_key, category_val, contains_pings)
+        categories.append(cat)
+
+    with filepath.open("w", encoding="utf-8") as fd:
+        fd.write(
+            template.render(
+                parser_version=__version__,
+                categories=categories,
+                extra_metric_args=util.extra_metric_args,
+                common_metric_args=util.common_metric_args,
+            )
+        )
@@ -0,0 +1,196 @@
+// -*- mode: Rust -*-
+
+// AUTOGENERATED BY glean_parser v{{ parser_version }}. DO NOT EDIT. DO NOT COMMIT.
+{# The rendered source is autogenerated, but this
+Jinja2 template is not. Please file bugs! #}
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+{%- macro generate_structure(name, struct) %}
+{%- if struct.type == "oneof" -%}
+    #[derive(Debug, Hash, Eq, PartialEq, Clone, ::glean_sym::__serde::Serialize, ::glean_sym::__serde::Deserialize)]
+    #[serde(crate = "::glean_sym::__serde")]
+    #[serde(untagged)]
+    pub enum {{ name }} {
+        {% for ty in struct.subtypes %}
+          {{ty|Camelize}}({{ty|structure_type_name}}),
+        {% endfor %}
+    }
+{% elif struct.type == "array" %}
+    pub type {{ name }} = Vec<{{ name }}Item>;
+
+    {{ generate_structure(name ~ "Item", struct["items"]) }}
+
+{% elif struct.type == "object" %}
+    #[derive(Debug, Hash, Eq, PartialEq, Clone, ::glean_sym::__serde::Serialize, ::glean_sym::__serde::Deserialize)]
+    #[serde(crate = "::glean_sym::__serde")]
+    #[serde(deny_unknown_fields)]
+    pub struct {{ name }} {
+        {% for itemname, val in struct.properties.items() %}
+          {% if val.type == "array" %}
+          #[serde(skip_serializing_if = "Vec::is_empty", default = "Vec::new", deserialize_with = "::glean_sym::__serde_helper::vec_null")]
+          pub {{itemname|snake_case}}: {{ name ~ itemname|Camelize }},
+          {% elif val.type == "object" %}
+          #[serde(skip_serializing_if = "Option::is_none")]
+          pub {{itemname|snake_case}}: Option<{{ name ~ "Item" ~ itemname|Camelize ~ "Object" }}>,
+          {% elif val.type == "oneof" %}
+          #[serde(skip_serializing_if = "Option::is_none")]
+          pub {{itemname|snake_case}}: Option<{{ name ~ itemname|Camelize ~ "Enum" }}>,
+          {% else %}
+          #[serde(skip_serializing_if = "Option::is_none")]
+          pub {{itemname|snake_case}}: Option<{{val.type|structure_type_name}}>,
+          {% endif %}
+        {% endfor %}
+    }
+
+    {% for itemname, val in struct.properties.items() %}
+        {% if val.type == "array" %}
+        {% set nested_name = name ~ itemname|Camelize %}
+        {{ generate_structure(nested_name, val) }}
+        {% elif val.type == "object" %}
+        {% set nested_name = name ~ "Item" ~ itemname|Camelize ~ "Object" %}
+        {{ generate_structure(nested_name, val) }}
+        {% elif val.type == "oneof" %}
+        {% set nested_name = name ~ itemname|Camelize ~ "Enum" %}
+        {{ generate_structure(nested_name, val) }}
+        {% endif %}
+    {% endfor %}
+
+{% else %}
+
+pub type {{ name }} = {{ struct.type|structure_type_name }};
+
+{% endif %}
+
+{% endmacro %}
+
+{% macro generate_extra_keys(obj) %}
+{% for name, _ in obj["_generate_enums"] %}
+{# we always use the `extra` suffix, because we only expose the new event API #}
+{% set suffix = "Extra" %}
+{% if obj|attr(name)|length %}
+    {{ extra_keys_with_types(obj, name, suffix)|indent }}
+{% endif %}
+{% endfor %}
+{% endmacro %}
+{% macro extra_keys_with_types(obj, name, suffix) %}
+#[derive(Default, Debug, Clone, Hash, Eq, PartialEq)]
+pub struct {{ obj.name|Camelize }}{{ suffix }} {
+    {% for item, type in obj|attr(name) %}
+    pub {{ item|snake_case }}: Option<{{type|extra_type_name}}>,
+    {% endfor %}
+}
+
+impl ExtraKeys for {{ obj.name|Camelize }}{{ suffix }} {
+    const ALLOWED_KEYS: &'static [&'static str] = {{ obj.allowed_extra_keys|extra_keys }};
+
+    fn into_ffi_extra(self) -> ::std::collections::HashMap<::std::string::String, ::std::string::String> {
+        let mut map = ::std::collections::HashMap::new();
+        {% for key, _ in obj|attr(name) %}
+        self.{{key|snake_case}}.and_then(|val| map.insert("{{key}}".to_string(), val.to_string()));
+        {% endfor %}
+        map
+    }
+}
+{% endmacro %}
+{% macro common_metric_data(obj) %}
+CommonMetricData {
+    category: {{ obj.category|rust }},
+    name: {{ obj.name|rust }},
+    send_in_pings: {{ obj.send_in_pings|rust }},
+    lifetime: {{ obj.lifetime|rust }},
+    disabled: {{ obj.is_disabled()|rust }},
+    ..Default::default()
+}
+{%- endmacro -%}
+{% for category in categories %}
+{% if category.contains_pings %}
+{% for obj in category.objs.values() %}
+#[allow(non_upper_case_globals, dead_code)]
+/// {{ obj.description|wordwrap() | replace('\n', '\n/// ') }}
+#[rustfmt::skip]
+pub static {{ obj.name|snake_case }}: ::glean_sym::__export::Lazy<::glean_sym::PingType> =
+    ::glean_sym::__export::Lazy::new(|| ::glean_sym::PingType::new("{{ obj.name }}", {{ obj.include_client_id|rust }}, {{ obj.send_if_empty|rust }}, {{ obj.precise_timestamps|rust }}, {{ obj.include_info_sections|rust }}, {{ obj.enabled|rust }}, {{ obj.schedules_pings|rust }}, {{ obj.reason_codes|rust }}, {{ obj.follows_collection_enabled|rust }}, {{ obj.uploader_capabilities|rust }}));
+{% endfor %}
+{% else %}
+pub mod {{ category.name|snake_case }} {
+    #[allow(unused_imports)] // HistogramType might be unusued, let's avoid warnings
+    use glean_sym::{metrics::*, types::*};
+    {% for obj in category.objs.values() %}
+
+    {% if obj|attr("_generate_structure") %}
+{{ generate_structure(obj.name|Camelize ~ "Object", obj._generate_structure) }}
+    {%- endif %}
+
+    {% if obj|attr("_generate_enums") %}
+{{ generate_extra_keys(obj) }}
+    {%- endif %}
+    #[allow(non_upper_case_globals, dead_code)]
+    /// generated from {{ category.name }}.{{ obj.name }}
+    ///
+    /// {{ obj.description|wordwrap() | replace('\n', '\n    /// ') }}
+    pub static {{ obj.name|snake_case }}: ::glean_sym::__export::Lazy<{{ obj|type_name }}> = ::glean_sym::__export::Lazy::new(|| {
+        let meta =
+            {% if obj.type == "labeled_custom_distribution" %}
+            LabeledMetricData::CustomDistribution {
+                cmd: {{ common_metric_data(obj)|indent(16) }}
+                {%- for arg_name in extra_metric_args if obj[arg_name] is defined and arg_name != 'allowed_extra_keys' -%}
+                    , {{ arg_name }}: {{ obj[arg_name]|rust }}
+                {%- endfor -%}
+            };
+            {% elif obj.type == "labeled_memory_distribution" %}
+            LabeledMetricData::MemoryDistribution {
+                cmd: {{ common_metric_data(obj)|indent(16) }}
+                {%- for arg_name in extra_metric_args if obj[arg_name] is defined and arg_name != 'allowed_extra_keys' -%}
+                    , {{ "unit" if arg_name == "memory_unit" else arg_name }}: {{ obj[arg_name]|rust }}
+                {%- endfor -%}
+            };
+            {% elif obj.type == "labeled_timing_distribution" %}
+            LabeledMetricData::TimingDistribution {
+                cmd: {{ common_metric_data(obj)|indent(16) }}
+                {%- for arg_name in extra_metric_args if obj[arg_name] is defined and arg_name != 'allowed_extra_keys' -%}
+                    , {{ "unit" if arg_name == "time_unit" else arg_name }}: {{ obj[arg_name]|rust }}
+                {%- endfor -%}
+            };
+            {% elif obj.labeled %}
+            LabeledMetricData::Common {
+                cmd: {{common_metric_data(obj)|indent(16) }},
+            };
+            {% else %}
+            {{ common_metric_data(obj)|indent(12) }};
+            {% endif %}
+        {{ obj|ctor }}(meta
+        {%- for arg_name in extra_metric_args if not obj.labeled and obj[arg_name] is defined and arg_name != 'allowed_extra_keys' -%}
+            , {{ obj[arg_name]|rust }}
+        {%- endfor -%}
+        {{ ", " if obj.labeled or obj.dual_labeled else ")\n" }}
+        {%- if obj.labeled -%}
+        {%- if obj.labels -%}
+        Some({{ obj.labels|rust }})
+        {%- else -%}
+        None
+        {%- endif -%})
+        {% endif %}
+        {%- if obj.dual_labeled -%}
+        {%- if obj.keys -%}
+        Some({{ obj.keys|rust }})
+        {%- else -%}
+        None
+        {%- endif -%}
+        {{ ", " }}
+        {%- if obj.categories -%}
+        Some({{ obj.categories|rust }})
+        {%- else -%}
+        None
+        {%- endif -%})
+        {% endif %}
+    });
+    {% endfor %}
+}
+{% endif %}
+{% endfor %}
+{% if metric_by_type|length > 0 %}
+
+{% endif %}
@@ -26,6 +26,7 @@
 from . import ruby_server
 from . import rust
 from . import rust_server
+from . import rust_sym
 from . import swift
 from . import util
 
@@ -68,6 +69,7 @@ def __init__(
     "swift": Outputter(swift.output_swift, ["*.swift"]),
     "rust": Outputter(rust.output_rust, []),
     "rust_server": Outputter(rust_server.output_rust, []),
+    "rust_sym": Outputter(rust_sym.output_rust, []),
 }
 
 

@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+
+# Very minimal testing for `rust_sym` support.
+# We're reusing most of the `rust` translator work,
+# so we're only testing that the generated code is at least still valid Rust.
+
+from pathlib import Path
+import shutil
+import subprocess
+
+from glean_parser import translate
+
+
+ROOT = Path(__file__).parent
+
+
+def run_linters(files):
+    # Syntax check on the generated files.
+    # Only run this test if cargo is on the path.
+    if shutil.which("rustfmt"):
+        for filepath in files:
+            subprocess.check_call(
+                [
+                    "rustfmt",
+                    "--check",
+                    filepath,
+                ]
+            )
+    if shutil.which("cargo"):
+        for filepath in files:
+            subprocess.check_call(
+                [
+                    "cargo",
+                    "clippy",
+                    "--all",
+                    "--",
+                    "-D",
+                    "warnings",
+                    filepath,
+                ]
+            )
+
+
+def test_parser(tmp_path):
+    """Test translating metrics to Rust files."""
+    translate.translate(
+        ROOT / "data" / "core.yaml", "rust_sym", tmp_path, {}, {"allow_reserved": True}
+    )
+
+    assert set(x.name for x in tmp_path.iterdir()) == set(["glean_metrics.rs"])
+
+    # Make sure descriptions made it in
+    with (tmp_path / "glean_metrics.rs").open("r", encoding="utf-8") as fd:
+        content = fd.read()
+
+        assert "True if the user has set Firefox as the default browser." in content
+        assert "جمع 搜集" in content
+        assert 'category: "telemetry"' in content