Add an --incompatible_remove_transitive_libs_from_dep_info flag (#1057)

As per #1051.

docs/flatten.md

@@ -1395,7 +1395,7 @@ A provider containing information about a Crate's dependencies.
 | <a id="DepInfo-transitive_build_infos"></a>transitive_build_infos |  depset[BuildInfo]    |
 | <a id="DepInfo-transitive_crate_outputs"></a>transitive_crate_outputs |  depset[File]: All transitive crate outputs.    |
 | <a id="DepInfo-transitive_crates"></a>transitive_crates |  depset[CrateInfo]    |
-| <a id="DepInfo-transitive_libs"></a>transitive_libs |  List[File]: All transitive dependencies, not filtered by type.    |
+| <a id="DepInfo-transitive_libs"></a>transitive_libs |  List[File]: (Deprecated, see https://github.com/bazelbuild/rules_rust/issues/1051) All transitive dependencies, not filtered by type.    |
 | <a id="DepInfo-transitive_noncrates"></a>transitive_noncrates |  depset[LinkerInput]: All transitive dependencies that aren't crates.    |
 
 

docs/providers.md

@@ -58,7 +58,7 @@ A provider containing information about a Crate's dependencies.
 | <a id="DepInfo-transitive_build_infos"></a>transitive_build_infos |  depset[BuildInfo]    |
 | <a id="DepInfo-transitive_crate_outputs"></a>transitive_crate_outputs |  depset[File]: All transitive crate outputs.    |
 | <a id="DepInfo-transitive_crates"></a>transitive_crates |  depset[CrateInfo]    |
-| <a id="DepInfo-transitive_libs"></a>transitive_libs |  List[File]: All transitive dependencies, not filtered by type.    |
+| <a id="DepInfo-transitive_libs"></a>transitive_libs |  List[File]: (Deprecated, see https://github.com/bazelbuild/rules_rust/issues/1051) All transitive dependencies, not filtered by type.    |
 | <a id="DepInfo-transitive_noncrates"></a>transitive_noncrates |  depset[LinkerInput]: All transitive dependencies that aren't crates.    |
 
 

rust/private/clippy.bzl

@@ -71,6 +71,7 @@ def _clippy_aspect_impl(target, ctx):
         # Clippy doesn't need to invoke transitive linking, therefore doesn't need linkstamps.
         are_linkstamps_supported = False,
         make_rust_providers_target_independent = toolchain._incompatible_make_rust_providers_target_independent,
+        remove_transitive_libs_from_dep_info = toolchain._incompatible_remove_transitive_libs_from_dep_info,
     )
 
     compile_inputs, out_dir, build_env_files, build_flags_files, linkstamp_outs = collect_inputs(

rust/private/providers.bzl

@@ -48,7 +48,8 @@ DepInfo = provider(
         "transitive_build_infos": "depset[BuildInfo]",
         "transitive_crate_outputs": "depset[File]: All transitive crate outputs.",
         "transitive_crates": "depset[CrateInfo]",
-        "transitive_libs": "List[File]: All transitive dependencies, not filtered by type.",
+        "transitive_libs": "List[File]: (Deprecated, see https://github.com/bazelbuild/rules_rust/issues/1051) " +
+                           "All transitive dependencies, not filtered by type.",
         "transitive_noncrates": "depset[LinkerInput]: All transitive dependencies that aren't crates.",
     },
 )

rust/private/rustc.bzl

@@ -112,7 +112,14 @@ def _are_linkstamps_supported(feature_configuration, has_grep_includes):
             # attribute is required for compiling linkstamps.
             has_grep_includes)
 
-def collect_deps(label, deps, proc_macro_deps, aliases, are_linkstamps_supported = False, make_rust_providers_target_independent = False):
+def collect_deps(
+        label,
+        deps,
+        proc_macro_deps,
+        aliases,
+        are_linkstamps_supported = False,
+        make_rust_providers_target_independent = False,
+        remove_transitive_libs_from_dep_info = False):
     """Walks through dependencies and collects the transitive dependencies.
 
     Args:
@@ -123,6 +130,8 @@ def collect_deps(label, deps, proc_macro_deps, aliases, are_linkstamps_supported
         are_linkstamps_supported (bool): Whether the current rule and the toolchain support building linkstamps.
         make_rust_providers_target_independent (bool): Whether
             --incompatible_make_rust_providers_target_independent has been flipped.
+        remove_transitive_libs_from_dep_info (bool): Whether
+            --incompatible_remove_transitive_libs_from_dep_info has been flipped.
 
     Returns:
         tuple: Returns a tuple of:
@@ -175,14 +184,16 @@ def collect_deps(label, deps, proc_macro_deps, aliases, are_linkstamps_supported
                 ),
             )
             transitive_noncrates.append(dep_info.transitive_noncrates)
-            transitive_noncrate_libs.append(dep_info.transitive_libs)
+            if not remove_transitive_libs_from_dep_info:
+                transitive_noncrate_libs.append(dep_info.transitive_libs)
             transitive_build_infos.append(dep_info.transitive_build_infos)
         elif cc_info:
             # This dependency is a cc_library
-            transitive_noncrate_libs.append(depset(
-                _collect_libs_from_linker_inputs(cc_info.linking_context.linker_inputs.to_list()),
-            ))
             transitive_noncrates.append(cc_info.linking_context.linker_inputs)
+            if not remove_transitive_libs_from_dep_info:
+                transitive_noncrate_libs.append(depset(
+                    _collect_libs_from_linker_inputs(cc_info.linking_context.linker_inputs.to_list()),
+                ))
         elif dep_build_info:
             if build_info:
                 fail("Several deps are providing build information, " +
@@ -194,10 +205,12 @@ def collect_deps(label, deps, proc_macro_deps, aliases, are_linkstamps_supported
                  "targets.")
 
     transitive_crates_depset = depset(transitive = transitive_crates)
-    transitive_libs = depset(
-        [c.output for c in transitive_crates_depset.to_list()],
-        transitive = transitive_noncrate_libs,
-    )
+    transitive_libs = depset([])
+    if not remove_transitive_libs_from_dep_info:
+        transitive_libs = depset(
+            [c.output for c in transitive_crates_depset.to_list()],
+            transitive = transitive_noncrate_libs,
+        )
 
     return (
         rust_common.dep_info(
@@ -719,6 +732,7 @@ def rustc_compile_action(
     cc_toolchain, feature_configuration = find_cc_toolchain(ctx)
 
     make_rust_providers_target_independent = toolchain._incompatible_make_rust_providers_target_independent
+    remove_transitive_libs_from_dep_info = toolchain._incompatible_remove_transitive_libs_from_dep_info
 
     dep_info, build_info, linkstamps = collect_deps(
         label = ctx.label,
@@ -730,6 +744,7 @@ def rustc_compile_action(
             has_grep_includes = hasattr(ctx.attr, "_grep_includes"),
         ),
         make_rust_providers_target_independent = make_rust_providers_target_independent,
+        remove_transitive_libs_from_dep_info = remove_transitive_libs_from_dep_info,
     )
 
     # Determine if the build is currently running with --stamp

rust/private/rustdoc.bzl

@@ -76,6 +76,7 @@ def rustdoc_compile_action(
         deps = crate_info.deps,
         proc_macro_deps = crate_info.proc_macro_deps,
         aliases = crate_info.aliases,
+        remove_transitive_libs_from_dep_info = toolchain._incompatible_remove_transitive_libs_from_dep_info,
     )
 
     compile_inputs, out_dir, build_env_files, build_flags_files, linkstamp_outs = collect_inputs(

rust/settings/BUILD.bazel

@@ -9,6 +9,12 @@ incompatible_flag(
     issue = "https://github.com/bazelbuild/rules_rust/issues/966",
 )
 
+incompatible_flag(
+    name = "incompatible_remove_transitive_libs_from_dep_info",
+    build_setting_default = False,
+    issue = "https://github.com/bazelbuild/rules_rust/issues/1051",
+)
+
 bzl_library(
     name = "rules",
     srcs = glob(["**/*.bzl"]),

rust/toolchain.bzl

@@ -232,6 +232,7 @@ def _rust_toolchain_impl(ctx):
         fail("Do not specify both target_triple and target_json, either use a builtin triple or provide a custom specification file.")
 
     make_rust_providers_target_independent = ctx.attr._incompatible_make_rust_providers_target_independent[IncompatibleFlagInfo]
+    remove_transitive_libs_from_dep_info = ctx.attr._incompatible_remove_transitive_libs_from_dep_info[IncompatibleFlagInfo]
 
     expanded_stdlib_linkflags = []
     for flag in ctx.attr.stdlib_linkflags:
@@ -284,6 +285,7 @@ def _rust_toolchain_impl(ctx):
         crosstool_files = ctx.files._crosstool,
         libstd_and_allocator_ccinfo = _make_libstd_and_allocator_ccinfo(ctx, ctx.attr.rust_lib, ctx.attr.allocator_library),
         _incompatible_make_rust_providers_target_independent = make_rust_providers_target_independent.enabled,
+        _incompatible_remove_transitive_libs_from_dep_info = remove_transitive_libs_from_dep_info.enabled,
     )
     return [toolchain]
 
@@ -399,6 +401,9 @@ rust_toolchain = rule(
         "_incompatible_make_rust_providers_target_independent": attr.label(
             default = "@rules_rust//rust/settings:incompatible_make_rust_providers_target_independent",
         ),
+        "_incompatible_remove_transitive_libs_from_dep_info": attr.label(
+            default = "@rules_rust//rust/settings:incompatible_remove_transitive_libs_from_dep_info",
+        ),
     },
     toolchains = [
         "@bazel_tools//tools/cpp:toolchain_type",

test/unit/deprecate_transitive_libs_in_dep_info/BUILD.bazel

@@ -0,0 +1,8 @@
+load(
+    ":deprecate_transitive_libs_in_dep_info_test.bzl",
+    "deprecate_transitive_libs_in_dep_info_test_suite",
+)
+
+deprecate_transitive_libs_in_dep_info_test_suite(
+    name = "deprecate_transitive_libs_in_dep_info_test_suite",
+)

test/unit/deprecate_transitive_libs_in_dep_info/bar.rs

@@ -0,0 +1 @@
+

test/unit/deprecate_transitive_libs_in_dep_info/deprecate_transitive_libs_in_dep_info_test.bzl

@@ -0,0 +1,82 @@
+"""Unittests for rust rules."""
+
+load("@bazel_skylib//lib:unittest.bzl", "analysistest", "asserts")
+load("//rust:defs.bzl", "rust_common", "rust_library")
+
+def _transitive_libs_in_dep_info_not_deprecated_impl(ctx):
+    env = analysistest.begin(ctx)
+    tut = analysistest.target_under_test(env)
+    transitive_libs = tut[rust_common.dep_info].transitive_libs.to_list()
+
+    asserts.true(
+        env,
+        len(transitive_libs) > 0,
+        "Expected DepInfo.transitive_libs to not be empty",
+    )
+
+    return analysistest.end(env)
+
+def _transitive_libs_in_dep_info_deprecated_impl(ctx):
+    env = analysistest.begin(ctx)
+    tut = analysistest.target_under_test(env)
+    transitive_libs = tut[rust_common.dep_info].transitive_libs.to_list()
+
+    asserts.true(
+        env,
+        len(transitive_libs) == 0,
+        "Expected DepInfo.transitive_libs to be empty, got {}".format(transitive_libs),
+    )
+
+    return analysistest.end(env)
+
+transitive_libs_in_dep_info_not_deprecated_test = analysistest.make(
+    _transitive_libs_in_dep_info_not_deprecated_impl,
+    config_settings = {
+        "@//rust/settings:incompatible_remove_transitive_libs_from_dep_info": False,
+    },
+)
+
+transitive_libs_in_dep_info_deprecated_test = analysistest.make(
+    _transitive_libs_in_dep_info_deprecated_impl,
+    config_settings = {
+        "@//rust/settings:incompatible_remove_transitive_libs_from_dep_info": True,
+    },
+)
+
+def _transitive_libs_in_dep_info_test():
+    rust_library(
+        name = "foo",
+        srcs = ["foo.rs"],
+        deps = [":bar"],
+    )
+
+    rust_library(
+        name = "bar",
+        srcs = ["bar.rs"],
+    )
+
+    transitive_libs_in_dep_info_not_deprecated_test(
+        name = "transitive_libs_in_dep_info_not_deprecated_test",
+        target_under_test = ":foo",
+    )
+
+    transitive_libs_in_dep_info_deprecated_test(
+        name = "transitive_libs_in_dep_info_deprecated_test",
+        target_under_test = ":foo",
+    )
+
+def deprecate_transitive_libs_in_dep_info_test_suite(name):
+    """Entry-point macro called from the BUILD file.
+
+    Args:
+        name: Name of the macro.
+    """
+    _transitive_libs_in_dep_info_test()
+
+    native.test_suite(
+        name = name,
+        tests = [
+            ":transitive_libs_in_dep_info_not_deprecated_test",
+            ":transitive_libs_in_dep_info_deprecated_test",
+        ],
+    )

test/unit/deprecate_transitive_libs_in_dep_info/foo.rs

@@ -0,0 +1 @@
+