Speedup collect_deps (#3634)

The key insight is that `deps` and `proc_macro_deps` must be disjoint,
so the depset.to_list is not doing any deduping. With that out of the
way, we do a bit of code rearranging to avoid converting our lists of
deps to depsets too early; in general it is best to construct the output
depsets when creating the providers, not in the middle of the rule
implementations.

Before:
<img width="1682" height="99" alt="image"
src="https://github.com/user-attachments/assets/eb0f9080-f5d5-4ab0-bc1e-1698dfc5d888"
/>

After:
<img width="1681" height="113" alt="image"
src="https://github.com/user-attachments/assets/fc5c8344-3819-4b92-ac43-3f088a3b2f1a"
/>

Author: dzbarsky

extensions/prost/private/prost.bzl

@@ -209,8 +209,8 @@ def _compile_rust(
             type = "rlib",
             root = src,
             srcs = depset([src]),
-            deps = depset(deps),
-            proc_macro_deps = depset([]),
+            deps = deps,
+            proc_macro_deps = [],
             aliases = {},
             output = lib,
             metadata = rmeta,

extensions/protobuf/proto.bzl

@@ -215,11 +215,9 @@ def _rust_proto_compile(protos, descriptor_sets, imports, crate_name, ctx, is_gr
         metadata_supports_pipelining = can_use_metadata_for_pipelining(toolchain, "rlib")
 
     # Gather all dependencies for compilation
-    compile_action_deps = depset(
-        transform_deps(
-            compile_deps +
-            proto_toolchain.grpc_compile_deps if is_grpc else proto_toolchain.proto_compile_deps,
-        ),
+    compile_action_deps = transform_deps(
+        compile_deps +
+        proto_toolchain.grpc_compile_deps if is_grpc else proto_toolchain.proto_compile_deps,
     )
 
     providers = rustc_compile_action(
@@ -232,7 +230,7 @@ def _rust_proto_compile(protos, descriptor_sets, imports, crate_name, ctx, is_gr
             root = lib_rs,
             srcs = depset(srcs),
             deps = compile_action_deps,
-            proc_macro_deps = depset([]),
+            proc_macro_deps = [],
             aliases = {},
             output = rust_lib,
             metadata = rust_metadata,

extensions/wasm_bindgen/private/wasm_bindgen_test.bzl

@@ -122,8 +122,8 @@ def _rust_wasm_bindgen_test_impl(ctx):
         type = crate_type,
         root = crate.root,
         srcs = depset(srcs, transitive = [crate.srcs]),
-        deps = depset(deps, transitive = [crate.deps]),
-        proc_macro_deps = depset(proc_macro_deps, transitive = [crate.proc_macro_deps]),
+        deps = depset(deps, transitive = [crate.deps]).to_list(),
+        proc_macro_deps = depset(proc_macro_deps, transitive = [crate.proc_macro_deps]).to_list(),
         aliases = {},
         output = output,
         rustc_output = generate_output_diagnostics(ctx, output),

rust/private/clippy.bzl

@@ -116,8 +116,8 @@ def _clippy_aspect_impl(target, ctx):
     cc_toolchain, feature_configuration = find_cc_toolchain(ctx)
 
     dep_info, build_info, _ = collect_deps(
-        deps = crate_info.deps,
-        proc_macro_deps = crate_info.proc_macro_deps,
+        deps = crate_info.deps.to_list(),
+        proc_macro_deps = crate_info.proc_macro_deps.to_list(),
         aliases = crate_info.aliases,
     )
 

rust/private/rust.bzl

@@ -221,8 +221,8 @@ def _rust_library_common(ctx, crate_type):
             type = crate_type,
             root = crate_root,
             srcs = depset(srcs),
-            deps = depset(deps),
-            proc_macro_deps = depset(proc_macro_deps),
+            deps = deps,
+            proc_macro_deps = proc_macro_deps,
             aliases = ctx.attr.aliases,
             output = rust_lib,
             rustc_output = generate_output_diagnostics(ctx, rust_lib),
@@ -286,8 +286,8 @@ def _rust_binary_impl(ctx):
             type = ctx.attr.crate_type,
             root = crate_root,
             srcs = depset(srcs),
-            deps = depset(deps),
-            proc_macro_deps = depset(proc_macro_deps),
+            deps = deps,
+            proc_macro_deps = proc_macro_deps,
             aliases = ctx.attr.aliases,
             output = output,
             rustc_output = generate_output_diagnostics(ctx, output),
@@ -418,8 +418,8 @@ def _rust_test_impl(ctx):
             type = crate_type,
             root = crate.root,
             srcs = depset(srcs),
-            deps = depset(deps, transitive = [crate.deps]),
-            proc_macro_deps = depset(proc_macro_deps, transitive = [crate.proc_macro_deps]),
+            deps = depset(deps, transitive = [crate.deps]).to_list(),
+            proc_macro_deps = depset(proc_macro_deps, transitive = [crate.proc_macro_deps]).to_list(),
             aliases = aliases,
             output = output,
             rustc_output = generate_output_diagnostics(ctx, output),
@@ -484,8 +484,8 @@ def _rust_test_impl(ctx):
             type = crate_type,
             root = crate_root,
             srcs = depset(srcs),
-            deps = depset(deps),
-            proc_macro_deps = depset(proc_macro_deps),
+            deps = deps,
+            proc_macro_deps = proc_macro_deps,
             aliases = ctx.attr.aliases,
             output = output,
             rustc_output = generate_output_diagnostics(ctx, output),

rust/private/rustc.bzl

@@ -252,7 +252,7 @@ def collect_deps(
     transitive_metadata_outputs = []
 
     crate_deps = []
-    for dep in depset(transitive = [deps, proc_macro_deps]).to_list():
+    for dep in deps + proc_macro_deps:
         crate_group = None
 
         if type(dep) == "Target" and rust_common.crate_group_info in dep:
@@ -1223,7 +1223,13 @@ def rustc_compile_action(
             - (DepInfo): The transitive dependencies of this crate.
             - (DefaultInfo): The output file for this crate, and its runfiles.
     """
-    crate_info = rust_common.create_crate_info(**crate_info_dict)
+    deps = crate_info_dict.pop("deps")
+    proc_macro_deps = crate_info_dict.pop("proc_macro_deps")
+    crate_info = rust_common.create_crate_info(
+        deps = depset(deps),
+        proc_macro_deps = depset(proc_macro_deps),
+        **crate_info_dict
+    )
 
     build_metadata = crate_info_dict.get("metadata", None)
     rustc_output = crate_info_dict.get("rustc_output", None)
@@ -1243,8 +1249,8 @@ def rustc_compile_action(
             experimental_use_cc_common_link = toolchain._experimental_use_cc_common_link
 
     dep_info, build_info, linkstamps = collect_deps(
-        deps = crate_info_dict["deps"],
-        proc_macro_deps = crate_info_dict["proc_macro_deps"],
+        deps = deps,
+        proc_macro_deps = proc_macro_deps,
         aliases = crate_info_dict["aliases"],
     )
     extra_disabled_features = [RUST_LINK_CC_FEATURE]
@@ -1616,7 +1622,11 @@ def rustc_compile_action(
         crate_info_dict.update({
             "rustc_env": env,
         })
-        crate_info = rust_common.create_crate_info(**crate_info_dict)
+        crate_info = rust_common.create_crate_info(
+            deps = depset(deps),
+            proc_macro_deps = depset(proc_macro_deps),
+            **crate_info_dict
+        )
 
     if crate_info.type in ["staticlib", "cdylib"]:
         # These rules are not supposed to be depended on by other rust targets, and

rust/private/rustdoc.bzl

@@ -98,8 +98,8 @@ def rustdoc_compile_action(
     cc_toolchain, feature_configuration = find_cc_toolchain(ctx)
 
     dep_info, build_info, _ = collect_deps(
-        deps = crate_info.deps,
-        proc_macro_deps = crate_info.proc_macro_deps,
+        deps = crate_info.deps.to_list(),
+        proc_macro_deps = crate_info.proc_macro_deps.to_list(),
         aliases = crate_info.aliases,
     )
 

rust/private/unpretty.bzl

@@ -141,8 +141,8 @@ def _rust_unpretty_aspect_impl(target, ctx):
     cc_toolchain, feature_configuration = find_cc_toolchain(ctx)
 
     dep_info, build_info, _ = collect_deps(
-        deps = crate_info.deps,
-        proc_macro_deps = crate_info.proc_macro_deps,
+        deps = crate_info.deps.to_list(),
+        proc_macro_deps = crate_info.proc_macro_deps.to_list(),
         aliases = crate_info.aliases,
     )
     lint_files = []

test/unit/consistent_crate_name/with_modified_crate_name.bzl

@@ -40,8 +40,8 @@ def _with_modified_crate_name_impl(ctx):
             type = crate_type,
             root = crate_root,
             srcs = ctx.attr.src.files,
-            deps = depset(deps),
-            proc_macro_deps = depset([]),
+            deps = deps,
+            proc_macro_deps = [],
             aliases = {},
             output = rust_lib,
             owner = ctx.label,

test/unit/force_all_deps_direct/generator.bzl

@@ -56,8 +56,8 @@ def _generator_impl(ctx):
             type = crate_type,
             root = rs_file,
             srcs = depset([rs_file]),
-            deps = depset(deps),
-            proc_macro_deps = depset([]),
+            deps = deps,
+            proc_macro_deps = [],
             aliases = {},
             output = rust_lib,
             owner = ctx.label,