rust_analyzer: don't build a tree of RustAnalyzerInfos (#3028)
This patch adds an `id` to RustAnalyzerInfo, and replace all the
recursive RustAnalyzerInfos with the respective crate `id`s.
This fixes RustAnalyzerInfos becoming exponentially expensive to build
in the presence of aliases.
---
Before this patch, `RustAnalyzerInfo.deps` contains the RustAnalyzerInfo
of the target crate's deps, and so on recursively.
This forms a graph of Infos where there is one Info per target, but
multiple paths from one target to another.
e.g. these could all point to `bar`: `foo.deps[0] == foo.deps[1].deps[0]
== foo.aliases[0]`.
If we walk `foo` as a tree, we will see `bar` multiple times. Two
operations that do this are `print(info)` and `{info: 42}` which hashes
the object. As the graph grows, the number of paths grows
combinatorically.
`RustAnalyzerInfo.aliases` is defined as a dict from `RustAnalyzerInfo
=> string`, so building this triggers the slowdown.
It would be possible to fix this by e.g. replacing this dict with a list
of pairs.
However the work `rust_analyzer_aspect` does is fundamentally local and
does not need a recursive data structure. Eliminating it means we can
freely use these values as keys, print them, etc.
---
Timings for `ra_ap_rust-analyzer` (which heavily aliases its deps):
```
blaze build //third_party/bazel_rules/rules_rust/tools/rust_analyzer:gen_rust_project; \
time blaze run //third_party/bazel_rules/rules_rust/tools/rust_analyzer:gen_rust_project -- //third_party/rust/ra_ap_rust_analyzer/...
===Before===
Executed in 211.06 secs fish external
usr time 0.24 secs 0.00 micros 0.24 secs
sys time 1.24 secs 604.00 micros 1.24 sec
===After===
Executed in 3.24 secs fish external
usr time 0.15 secs 389.00 micros 0.15 secs
sys time 1.18 secs 125.00 micros 1.18 secs
```diff --git a/extensions/prost/private/prost.bzl b/extensions/prost/private/prost.bzl
index b05cf6d..c615a27 100644
--- a/extensions/prost/private/prost.bzl
+++ b/extensions/prost/private/prost.bzl
@@ -261,7 +261,10 @@
# https://github.com/rust-analyzer/rust-analyzer/blob/2021-11-15/crates/project_model/src/workspace.rs#L529-L531
cfgs = ["test", "debug_assertions"]
+ crate_id = "prost-" + dep_variant_info.crate_info.root.path
+
rust_analyzer_info = write_rust_analyzer_spec_file(ctx, ctx.rule.attr, ctx.label, RustAnalyzerInfo(
+ id = crate_id,
aliases = {},
crate = dep_variant_info.crate_info,
cfgs = cfgs,
@@ -332,7 +335,10 @@
transitive = transitive,
),
),
- RustAnalyzerGroupInfo(deps = [proto_dep[RustAnalyzerInfo]]),
+ RustAnalyzerGroupInfo(
+ crate_specs = proto_dep[RustAnalyzerInfo].crate_specs,
+ deps = proto_dep[RustAnalyzerInfo].deps,
+ ),
]
rust_prost_library = rule(
diff --git a/rust/private/providers.bzl b/rust/private/providers.bzl
index 97c4500..0482cab 100644
--- a/rust/private/providers.bzl
+++ b/rust/private/providers.bzl
@@ -157,13 +157,14 @@
RustAnalyzerInfo = provider(
doc = "RustAnalyzerInfo holds rust crate metadata for targets",
fields = {
- "aliases": "Dict[RustAnalyzerInfo, String]: Replacement names these targets should be known as in Rust code",
+ "aliases": "Dict[String, String]: Maps crate IDs to Replacement names these targets should be known as in Rust code",
"build_info": "BuildInfo: build info for this crate if present",
"cfgs": "List[String]: features or other compilation `--cfg` settings",
"crate": "CrateInfo: Crate information.",
"crate_specs": "Depset[File]: transitive closure of OutputGroupInfo files",
- "deps": "List[RustAnalyzerInfo]: direct dependencies",
+ "deps": "List[String]: IDs of direct dependency crates",
"env": "Dict[String: String]: Environment variables, used for the `env!` macro",
+ "id": "String: Arbitrary unique ID for this crate",
"proc_macro_dylib_path": "File: compiled shared library output of proc-macro rule",
},
)
@@ -171,6 +172,7 @@
RustAnalyzerGroupInfo = provider(
doc = "RustAnalyzerGroupInfo holds multiple RustAnalyzerInfos",
fields = {
- "deps": "List[RustAnalyzerInfo]: direct dependencies",
+ "crate_specs": "Depset[File]: transitive closure of OutputGroupInfo files",
+ "deps": "List[String]: crate IDs of direct dependencies",
},
)
diff --git a/rust/private/rust_analyzer.bzl b/rust/private/rust_analyzer.bzl
index bc12306..6673a45 100644
--- a/rust/private/rust_analyzer.bzl
+++ b/rust/private/rust_analyzer.bzl
@@ -53,6 +53,7 @@
cfgs = base_info.cfgs,
env = base_info.env,
deps = base_info.deps,
+ id = base_info.id,
crate_specs = depset(direct = [crate_spec], transitive = [base_info.crate_specs]),
proc_macro_dylib_path = base_info.proc_macro_dylib_path,
build_info = base_info.build_info,
@@ -72,21 +73,6 @@
return rust_analyzer_info
-def _accumulate_rust_analyzer_info(dep_infos_to_accumulate, label_index_to_accumulate, dep):
- if dep == None:
- return
- if RustAnalyzerInfo in dep:
- label_index_to_accumulate[dep.label] = dep[RustAnalyzerInfo]
- dep_infos_to_accumulate.append(dep[RustAnalyzerInfo])
- if RustAnalyzerGroupInfo in dep:
- for expanded_dep in dep[RustAnalyzerGroupInfo].deps:
- label_index_to_accumulate[expanded_dep.crate.owner] = expanded_dep
- dep_infos_to_accumulate.append(expanded_dep)
-
-def _accumulate_rust_analyzer_infos(dep_infos_to_accumulate, label_index_to_accumulate, deps_attr):
- for dep in deps_attr:
- _accumulate_rust_analyzer_info(dep_infos_to_accumulate, label_index_to_accumulate, dep)
-
def _rust_analyzer_aspect_impl(target, ctx):
if (rust_common.crate_info not in target and
rust_common.test_crate_info not in target and
@@ -107,22 +93,31 @@
cfgs += [f[6:] for f in ctx.rule.attr.rustc_flags if f.startswith("--cfg ") or f.startswith("--cfg=")]
build_info = None
- dep_infos = []
- labels_to_rais = {}
-
for dep in getattr(ctx.rule.attr, "deps", []):
# Save BuildInfo if we find any (for build script output)
if BuildInfo in dep:
build_info = dep[BuildInfo]
- _accumulate_rust_analyzer_infos(dep_infos, labels_to_rais, getattr(ctx.rule.attr, "deps", []))
- _accumulate_rust_analyzer_infos(dep_infos, labels_to_rais, getattr(ctx.rule.attr, "proc_macro_deps", []))
+ # Gather required info from dependencies.
+ label_to_id = {} # {Label of dependency => crate_id}
+ crate_specs = [] # [depset of File - transitive crate_spec.json files]
+ attrs = ctx.rule.attr
+ all_deps = getattr(attrs, "deps", []) + getattr(attrs, "proc_macro_deps", []) + \
+ [dep for dep in [getattr(attrs, "crate", None), getattr(attrs, "actual", None)] if dep != None]
+ for dep in all_deps:
+ if RustAnalyzerInfo in dep:
+ label_to_id[dep.label] = dep[RustAnalyzerInfo].id
+ crate_specs.append(dep[RustAnalyzerInfo].crate_specs)
+ if RustAnalyzerGroupInfo in dep:
+ for expanded_dep in dep[RustAnalyzerGroupInfo].deps:
+ label_to_id[expanded_dep] = expanded_dep
+ crate_specs.append(dep[RustAnalyzerGroupInfo].crate_specs)
- _accumulate_rust_analyzer_info(dep_infos, labels_to_rais, getattr(ctx.rule.attr, "crate", None))
- _accumulate_rust_analyzer_info(dep_infos, labels_to_rais, getattr(ctx.rule.attr, "actual", None))
+ deps = label_to_id.values()
+ crate_specs = depset(transitive = crate_specs)
if rust_common.crate_group_info in target:
- return [RustAnalyzerGroupInfo(deps = dep_infos)]
+ return [RustAnalyzerGroupInfo(deps = deps, crate_specs = crate_specs)]
elif rust_common.crate_info in target:
crate_info = target[rust_common.crate_info]
elif rust_common.test_crate_info in target:
@@ -130,18 +125,23 @@
else:
fail("Unexpected target type: {}".format(target))
- aliases = {}
- for aliased_target, aliased_name in getattr(ctx.rule.attr, "aliases", {}).items():
- if aliased_target.label in labels_to_rais:
- aliases[labels_to_rais[aliased_target.label]] = aliased_name
+ aliases = {
+ label_to_id[target.label]: name
+ for (target, name) in getattr(attrs, "aliases", {}).items()
+ if target.label in label_to_id
+ }
+
+ # An arbitrary unique and stable identifier.
+ crate_id = "ID-" + crate_info.root.path
rust_analyzer_info = write_rust_analyzer_spec_file(ctx, ctx.rule.attr, ctx.label, RustAnalyzerInfo(
+ id = crate_id,
aliases = aliases,
crate = crate_info,
cfgs = cfgs,
env = crate_info.rustc_env,
- deps = dep_infos,
- crate_specs = depset(transitive = [dep.crate_specs for dep in dep_infos]),
+ deps = deps,
+ crate_specs = crate_specs,
proc_macro_dylib_path = find_proc_macro_dylib_path(toolchain, target),
build_info = build_info,
))
@@ -193,14 +193,6 @@
_EXEC_ROOT_TEMPLATE = "__EXEC_ROOT__/"
_OUTPUT_BASE_TEMPLATE = "__OUTPUT_BASE__/"
-def _crate_id(crate_info):
- """Returns a unique stable identifier for a crate
-
- Returns:
- (string): This crate's unique stable id.
- """
- return "ID-" + crate_info.root.path
-
def _create_single_crate(ctx, attrs, info):
"""Creates a crate in the rust-project.json format.
@@ -214,8 +206,7 @@
"""
crate_name = info.crate.name
crate = dict()
- crate_id = _crate_id(info.crate)
- crate["crate_id"] = crate_id
+ crate["crate_id"] = info.id
crate["display_name"] = crate_name
crate["edition"] = info.crate.edition
crate["env"] = {}
@@ -263,8 +254,8 @@
# There's one exception - if the dependency is the same crate name as the
# the crate being processed, we don't add it as a dependency to itself. This is
# common and expected - `rust_test.crate` pointing to the `rust_library`.
- crate["deps"] = [_crate_id(dep.crate) for dep in info.deps if _crate_id(dep.crate) != crate_id]
- crate["aliases"] = {_crate_id(alias_target.crate): alias_name for alias_target, alias_name in info.aliases.items()}
+ crate["deps"] = [id for id in info.deps if id != info.id]
+ crate["aliases"] = info.aliases
crate["cfg"] = info.cfgs
toolchain = find_toolchain(ctx)
crate["target"] = (_EXEC_ROOT_TEMPLATE + toolchain.target_json.path) if toolchain.target_json else toolchain.target_flag_value
