| # Copyright 2021 The Bazel Authors. All rights reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """Implementation of cc_shared_library""" |
| |
| load(":common/cc/cc_common.bzl", "cc_common") |
| load(":common/cc/cc_helper.bzl", "cc_helper") |
| load(":common/cc/cc_info.bzl", "CcInfo") |
| load(":common/cc/cc_shared_library_hint_info.bzl", "CcSharedLibraryHintInfo") |
| load(":common/cc/semantics.bzl", "semantics") |
| load(":common/proto/proto_info.bzl", "ProtoInfo") |
| |
| # TODO(#5200): Add export_define to library_to_link and cc_library |
| |
| # Add this as a tag to any target that can be linked by more than one |
| # cc_shared_library because it doesn't have static initializers or anything |
| # else that may cause issues when being linked more than once. This should be |
| # used sparingly after making sure it's safe to use. |
| LINKABLE_MORE_THAN_ONCE = "LINKABLE_MORE_THAN_ONCE" |
| |
| GraphNodeInfo = provider( |
| "Nodes in the graph of shared libraries.", |
| fields = { |
| "children": "Other GraphNodeInfo from dependencies of this target", |
| "owners": "Owners of the linker inputs in the targets visited", |
| "linkable_more_than_once": "Linkable into more than a single cc_shared_library", |
| }, |
| ) |
| CcSharedLibraryInfo = provider( |
| "Information about a cc shared library.", |
| fields = { |
| "dynamic_deps": "All shared libraries depended on transitively", |
| "exports": "cc_libraries that are linked statically and exported", |
| "link_once_static_libs": "All libraries linked statically into this library that should " + |
| "only be linked once, e.g. because they have static " + |
| "initializers. If we try to link them more than once, " + |
| "we will throw an error", |
| "linker_input": "the resulting linker input artifact for the shared library", |
| }, |
| ) |
| |
| def _programmatic_error(message = ""): |
| fail("Your build has triggered a programmatic error in the cc_shared_library rule. " + |
| "Please file an issue in https://github.com/bazelbuild/bazel : {}".format(message)) |
| |
| def _sort_linker_inputs(topologically_sorted_labels, label_to_linker_inputs, linker_inputs_count): |
| # len(label_to_linker_inputs) might not match the topologically_sorted_labels |
| # size. The latter is looking at nodes in the graph but a node may not |
| # necessarily contribute any linker_inputs. For example a cc_library with |
| # no sources and only deps. Every linker_input.owner must be in |
| # topologically_sorted_labels otherwise there is an error in the rule |
| # implementation of the target providing that linker_input, e.g. it's |
| # missing a CcSharedLibraryHintInfo if it had custom owner names for linker |
| # inputs. |
| sorted_linker_inputs = [] |
| for label in topologically_sorted_labels: |
| if label not in label_to_linker_inputs: |
| # This is ok. It can happen if no linker_inputs |
| # were added by a node in the graph. |
| continue |
| sorted_linker_inputs.extend(label_to_linker_inputs[label]) |
| |
| if len(sorted_linker_inputs) != linker_inputs_count: |
| owners = [] |
| for sorted_linker_input in sorted_linker_inputs: |
| owners.append(str(sorted_linker_input.owner)) |
| _programmatic_error("{} vs {}".format(",".join(owners), linker_inputs_count)) |
| |
| return sorted_linker_inputs |
| |
| # For each target, find out whether it should be linked statically or |
| # dynamically. The transitive_dynamic_dep_labels parameter is only needed for |
| # binaries because they link all dynamic_deps (cc_binary|cc_test). |
| def _separate_static_and_dynamic_link_libraries( |
| ctx, |
| direct_children, |
| can_be_linked_dynamically): |
| ( |
| transitive_dynamic_dep_labels, |
| all_dynamic_dep_linker_inputs, |
| ) = _build_map_direct_dynamic_dep_to_transitive_dynamic_deps(ctx) |
| |
| node = None |
| all_children = reversed(direct_children) |
| targets_to_be_linked_statically_map = {} |
| targets_to_be_linked_dynamically_set = {} |
| seen_labels = {} |
| |
| # The cc_shared_library graph is parallel to the cc_library graph. |
| # Propagation of linker inputs between cc_libraries happens via the CcInfo |
| # provider. Parallel to this we have cc_shared_libraries which may decide |
| # different partitions of the cc_library graph. |
| # |
| # In a previous implementation of cc_shared_library we relied on the |
| # topological sort given by flattening |
| # cc_info.linking_context.linker_inputs.to_list(), however this was wrong |
| # because the dependencies of a shared library (i.e. a pruned node here) |
| # influenced the final order. |
| # |
| # In order to fix this, the pruning below was changed from breadth-first |
| # traversal to depth-first traversal. While doing this we also recreate a |
| # depset with topological order that takes into account the pruned nodes |
| # and which will later be used to order the libraries in the linking |
| # command line. This will be in topological order and will respect the |
| # order of the deps as listed on the BUILD file as much as possible. |
| # |
| # Here we say "first_owner" because each node (see GraphNodeInfo) may have |
| # more than one linker_input (each potentially with a different owner) but |
| # using only the first owner as a key is enough. |
| first_owner_to_depset = {} |
| |
| # Horrible I know. Perhaps Starlark team gives me a way to prune a tree. |
| for i in range(2147483647): |
| if not len(all_children): |
| break |
| |
| node = all_children[-1] |
| |
| must_add_children = False |
| |
| # The *_seen variables are used to track a programmatic error and fail |
| # if it happens. Every value in node.owners presumably corresponds to |
| # a linker_input in the same exact target. Therefore if we have seen |
| # any of the owners already, then we must have also seen all the other |
| # owners in the same node. Viceversa when we haven't seen them yet. If |
| # both of these values are non-zero after the loop, the most likely |
| # reason would be a bug in the implementation. It could potentially be |
| # triggered by users if they use owner labels that do not keep most of |
| # the ctx.label.package and ctx.label.name which then clash with other |
| # target's owners (unlikely). For now though if the error is |
| # triggered, it's reasonable to require manual revision by |
| # the cc_shared_library implementation owners. |
| has_owners_seen = False |
| has_owners_not_seen = False |
| linked_dynamically = False |
| linked_statically = False |
| for owner in node.owners: |
| # TODO(bazel-team): Do not convert Labels to string to save on |
| # garbage string allocations. |
| owner_str = str(owner) |
| |
| if owner_str in seen_labels: |
| has_owners_seen = True |
| continue |
| |
| has_owners_not_seen = True |
| seen_labels[owner_str] = True |
| |
| if owner_str in can_be_linked_dynamically: |
| targets_to_be_linked_dynamically_set[owner_str] = True |
| linked_dynamically = True |
| else: |
| targets_to_be_linked_statically_map[owner_str] = node.linkable_more_than_once |
| must_add_children = True |
| linked_statically = True |
| |
| if has_owners_seen and has_owners_not_seen: |
| _programmatic_error() |
| |
| if linked_dynamically and linked_statically: |
| error_owners_list = [str(owner) for owner in node.owners] |
| |
| # Our granularity is target level. Unless there is a different |
| # unsupported custom implementation of this rule it should be |
| # impossible for two linker_inputs from the same target to be |
| # linked differently, one statically and the other dynamically. |
| _programmatic_error( |
| message = "Nodes with linker_inputs linked statically and dynamically:" + |
| "\n{}".format("\n".join(error_owners_list)), |
| ) |
| |
| if must_add_children: |
| # The order in which we process the children matter. all_children |
| # is being used as a stack, we will process first the nodes at the |
| # top of the stack (last in the list). The children are the |
| # dependencies of the current node, in order to respect the order |
| # in which dependencies were listed in the deps attribute in the |
| # BUILD file we must reverse the list so that the first one listed |
| # in the BUILD file is processed first. |
| all_children.extend(reversed(node.children)) |
| else: |
| if node.owners[0] not in first_owner_to_depset: |
| # We have 3 cases in this branch: |
| # 1. Node has no children |
| # 2. The children have been pruned because the node is linked dynamically |
| # 3. Node has children that have been processed |
| # For case 3 we add the children's depsets. For case 2 we add the dynamic |
| # dep labels for transitive dynamic deps. |
| transitive = [] |
| if str(node.owners[0]) in targets_to_be_linked_statically_map: |
| for child in node.children: |
| transitive.append(first_owner_to_depset[child.owners[0]]) |
| elif str(node.owners[0]) in transitive_dynamic_dep_labels: |
| transitive.append(transitive_dynamic_dep_labels[str(node.owners[0])]) |
| |
| first_owner_to_depset[node.owners[0]] = depset(direct = node.owners, transitive = transitive, order = "topological") |
| all_children.pop() |
| |
| topologically_sorted_labels = [] |
| if direct_children: |
| transitive = [] |
| for child in direct_children: |
| transitive.append(first_owner_to_depset[child.owners[0]]) |
| topologically_sorted_labels = depset(transitive = transitive, order = "topological").to_list() |
| |
| return (targets_to_be_linked_statically_map, targets_to_be_linked_dynamically_set, topologically_sorted_labels, all_dynamic_dep_linker_inputs) |
| |
| def _create_linker_context(ctx, linker_inputs): |
| return cc_common.create_linking_context( |
| linker_inputs = depset(linker_inputs, order = "topological"), |
| ) |
| |
| def _merge_cc_shared_library_infos(ctx): |
| dynamic_deps = [] |
| transitive_dynamic_deps = [] |
| for dep in ctx.attr.dynamic_deps: |
| dynamic_dep_entry = struct( |
| exports = dep[CcSharedLibraryInfo].exports, |
| linker_input = dep[CcSharedLibraryInfo].linker_input, |
| link_once_static_libs = dep[CcSharedLibraryInfo].link_once_static_libs, |
| ) |
| dynamic_deps.append(dynamic_dep_entry) |
| transitive_dynamic_deps.append(dep[CcSharedLibraryInfo].dynamic_deps) |
| |
| return depset(direct = dynamic_deps, transitive = transitive_dynamic_deps, order = "topological") |
| |
| def _build_exports_map_from_only_dynamic_deps(merged_shared_library_infos): |
| exports_map = {} |
| for entry in merged_shared_library_infos.to_list(): |
| exports = entry.exports |
| linker_input = entry.linker_input |
| for export in exports: |
| if export in exports_map: |
| fail("Two shared libraries in dependencies export the same symbols. Both " + |
| exports_map[export].libraries[0].dynamic_library.short_path + |
| " and " + linker_input.libraries[0].dynamic_library.short_path + |
| " export " + export) |
| exports_map[export] = linker_input |
| return exports_map |
| |
| # The map points from the target that can only be linked once to the |
| # cc_shared_library target that already links it. |
| def _build_link_once_static_libs_map(merged_shared_library_infos): |
| link_once_static_libs_map = {} |
| for entry in merged_shared_library_infos.to_list(): |
| link_once_static_libs = entry.link_once_static_libs |
| linker_input = entry.linker_input |
| for static_lib in link_once_static_libs: |
| if static_lib in link_once_static_libs_map: |
| fail("Two shared libraries in dependencies link the same " + |
| " library statically. Both " + link_once_static_libs_map[static_lib] + |
| " and " + str(linker_input.owner) + |
| " link statically " + static_lib) |
| link_once_static_libs_map[static_lib] = str(linker_input.owner) |
| return link_once_static_libs_map |
| |
| def _is_dynamic_only(library_to_link): |
| if (library_to_link.static_library == None and |
| library_to_link.pic_static_library == None and |
| (library_to_link.objects == None or len(library_to_link.objects) == 0) and |
| (library_to_link.pic_objects == None or len(library_to_link.pic_objects) == 0)): |
| return True |
| return False |
| |
| def _wrap_static_library_with_alwayslink(ctx, feature_configuration, cc_toolchain, linker_input): |
| new_libraries_to_link = [] |
| for old_library_to_link in linker_input.libraries: |
| if _is_dynamic_only(old_library_to_link): |
| new_libraries_to_link.append(old_library_to_link) |
| continue |
| new_library_to_link = cc_common.create_library_to_link( |
| actions = ctx.actions, |
| feature_configuration = feature_configuration, |
| cc_toolchain = cc_toolchain, |
| static_library = old_library_to_link.static_library, |
| objects = old_library_to_link.objects, |
| pic_static_library = old_library_to_link.pic_static_library, |
| pic_objects = old_library_to_link.pic_objects, |
| alwayslink = True, |
| ) |
| new_libraries_to_link.append(new_library_to_link) |
| |
| return cc_common.create_linker_input( |
| owner = linker_input.owner, |
| libraries = depset(direct = new_libraries_to_link), |
| user_link_flags = depset(direct = linker_input.user_link_flags), |
| additional_inputs = depset(direct = linker_input.additional_inputs), |
| ) |
| |
| def _check_if_target_under_path(value, pattern): |
| if pattern.workspace_name != value.workspace_name: |
| return False |
| if pattern.name == "__pkg__": |
| return pattern.package == value.package |
| if pattern.name == "__subpackages__": |
| return _same_package_or_above(pattern, value) |
| |
| return pattern.package == value.package and pattern.name == value.name |
| |
| def _check_if_target_should_be_exported_with_filter(target, current_label, exports_filter): |
| for export_filter in exports_filter: |
| export_filter_label = current_label.relative(export_filter) |
| if _check_if_target_under_path(target, export_filter_label): |
| return True |
| |
| return False |
| |
| # Checks if the linker_input has code to link statically, i.e. either |
| # archives or object files, ignores library.dynamic_library. |
| def _contains_code_to_link(linker_input): |
| for library in linker_input.libraries: |
| if (library.static_library != None or |
| library.pic_static_library != None or |
| len(library.objects) or len(library.pic_objects)): |
| return True |
| |
| return False |
| |
| def _find_top_level_linker_input_labels( |
| nodes, |
| linker_inputs_to_be_linked_statically_map, |
| targets_to_be_linked_dynamically_set): |
| top_level_linker_input_labels_set = {} |
| nodes_to_check = list(nodes) |
| |
| seen_nodes_set = {} |
| for i in range(2147483647): |
| if i == len(nodes_to_check): |
| break |
| |
| node = nodes_to_check[i] |
| must_add_children = False |
| node_str_owners = [] |
| for owner in node.owners: |
| owner_str = str(owner) |
| node_str_owners.append(owner_str) |
| if owner_str in linker_inputs_to_be_linked_statically_map: |
| must_add_children = True |
| for linker_input in linker_inputs_to_be_linked_statically_map[owner_str]: |
| if _contains_code_to_link(linker_input): |
| top_level_linker_input_labels_set[owner_str] = True |
| must_add_children = False |
| break |
| elif owner_str not in targets_to_be_linked_dynamically_set: |
| # This can happen when there was a target in the graph that exported other libraries' |
| # linker_inputs but didn't contribute any linker_input of its own. |
| must_add_children = True |
| |
| node_key = "".join(node_str_owners) |
| if must_add_children and node_key not in seen_nodes_set: |
| nodes_to_check.extend(node.children) |
| seen_nodes_set[node_key] = True |
| |
| return top_level_linker_input_labels_set |
| |
| def _filter_inputs( |
| ctx, |
| feature_configuration, |
| cc_toolchain, |
| deps, |
| transitive_exports, |
| link_once_static_libs_map): |
| curr_link_once_static_libs_set = {} |
| |
| graph_structure_aspect_nodes = [] |
| dependency_linker_inputs_sets = [] |
| direct_deps_set = {} |
| for dep in deps: |
| direct_deps_set[str(dep.label)] = True |
| dependency_linker_inputs_sets.append(dep[CcInfo].linking_context.linker_inputs) |
| graph_structure_aspect_nodes.append(dep[GraphNodeInfo]) |
| |
| if ctx.attr.experimental_disable_topo_sort_do_not_use_remove_before_7_0: |
| dependency_linker_inputs = depset(transitive = dependency_linker_inputs_sets).to_list() |
| else: |
| dependency_linker_inputs = depset(transitive = dependency_linker_inputs_sets, order = "topological").to_list() |
| |
| can_be_linked_dynamically = {} |
| for linker_input in dependency_linker_inputs: |
| owner = str(linker_input.owner) |
| if owner in transitive_exports: |
| can_be_linked_dynamically[owner] = True |
| |
| # The targets_to_be_linked_statically_map points to whether the target to |
| # be linked statically can be linked more than once. |
| # Entries in unused_dynamic_linker_inputs will be marked None if they are |
| # used |
| ( |
| targets_to_be_linked_statically_map, |
| targets_to_be_linked_dynamically_set, |
| topologically_sorted_labels, |
| unused_dynamic_linker_inputs, |
| ) = _separate_static_and_dynamic_link_libraries( |
| ctx, |
| graph_structure_aspect_nodes, |
| can_be_linked_dynamically, |
| ) |
| |
| linker_inputs_to_be_linked_statically_map = {} |
| for linker_input in dependency_linker_inputs: |
| owner = str(linker_input.owner) |
| if owner in targets_to_be_linked_statically_map: |
| linker_inputs_to_be_linked_statically_map.setdefault(owner, []).append(linker_input) |
| |
| top_level_linker_input_labels_set = _find_top_level_linker_input_labels( |
| graph_structure_aspect_nodes, |
| linker_inputs_to_be_linked_statically_map, |
| targets_to_be_linked_dynamically_set, |
| ) |
| |
| # We keep track of precompiled_only_dynamic_libraries, so that we can add |
| # them to runfiles. |
| precompiled_only_dynamic_libraries = [] |
| exports = {} |
| linker_inputs_seen = {} |
| linker_inputs_count = 0 |
| label_to_linker_inputs = {} |
| experimental_remove_before_7_0_linker_inputs = [] |
| |
| def _add_linker_input_to_dict(owner, linker_input): |
| experimental_remove_before_7_0_linker_inputs.append(linker_input) |
| label_to_linker_inputs.setdefault(owner, []).append(linker_input) |
| |
| # We use this dictionary to give an error if a target containing only |
| # precompiled dynamic libraries is placed directly in roots. If such a |
| # precompiled dynamic library is needed it would be because a target in the |
| # parallel cc_library graph actually needs it. Therefore the precompiled |
| # dynamic library should be made a dependency of that cc_library instead. |
| dynamic_only_roots = {} |
| linked_statically_but_not_exported = {} |
| for linker_input in dependency_linker_inputs: |
| stringified_linker_input = cc_helper.stringify_linker_input(linker_input) |
| if stringified_linker_input in linker_inputs_seen: |
| continue |
| linker_inputs_seen[stringified_linker_input] = True |
| owner = str(linker_input.owner) |
| if owner in targets_to_be_linked_dynamically_set: |
| unused_dynamic_linker_inputs[transitive_exports[owner].owner] = None |
| |
| # Link the library in this iteration dynamically, |
| # transitive_exports contains the artifacts produced by a |
| # cc_shared_library |
| _add_linker_input_to_dict(linker_input.owner, transitive_exports[owner]) |
| linker_inputs_count += 1 |
| elif owner in targets_to_be_linked_statically_map: |
| if semantics.is_bazel and not linker_input.libraries: |
| # TODO(bazel-team): semantics.should_create_empty_archive() should be |
| # cleaned up and return False in every case. cc_libraries shouldn't |
| # produce empty archives. For now issue #19920 is only fixed in Bazel. |
| continue |
| if owner in link_once_static_libs_map: |
| # We are building a dictionary that will allow us to give |
| # proper errors for libraries that have been linked multiple |
| # times elsewhere but haven't been exported. The values in the |
| # link_once_static_libs_map dictionary are the |
| # cc_shared_library targets. In this iteration we know of at |
| # least one target (i.e. owner) which is being linked |
| # statically by the cc_shared_library |
| # link_once_static_libs_map[owner] but is not being exported |
| linked_statically_but_not_exported.setdefault(link_once_static_libs_map[owner], []).append(owner) |
| |
| dynamic_only_libraries = [] |
| static_libraries = [] |
| for library in linker_input.libraries: |
| if _is_dynamic_only(library): |
| dynamic_only_libraries.append(library) |
| else: |
| static_libraries.append(library) |
| |
| if len(dynamic_only_libraries): |
| precompiled_only_dynamic_libraries.extend(dynamic_only_libraries) |
| if not len(static_libraries): |
| if owner in direct_deps_set: |
| dynamic_only_roots[owner] = True |
| _add_linker_input_to_dict(linker_input.owner, linker_input) |
| linker_inputs_count += 1 |
| continue |
| if len(static_libraries) and owner in dynamic_only_roots: |
| dynamic_only_roots.pop(owner) |
| |
| linker_input_to_be_linked_statically = linker_input |
| if owner in top_level_linker_input_labels_set: |
| linker_input_to_be_linked_statically = _wrap_static_library_with_alwayslink( |
| ctx, |
| feature_configuration, |
| cc_toolchain, |
| linker_input, |
| ) |
| if _check_if_target_should_be_exported_with_filter( |
| linker_input.owner, |
| ctx.label, |
| ctx.attr.exports_filter, |
| ): |
| exports[owner] = True |
| |
| _add_linker_input_to_dict(linker_input.owner, linker_input_to_be_linked_statically) |
| linker_inputs_count += 1 |
| |
| if not targets_to_be_linked_statically_map[owner]: |
| curr_link_once_static_libs_set[owner] = True |
| |
| if dynamic_only_roots: |
| message = ("Do not place libraries which only contain a " + |
| "precompiled dynamic library in roots. The following " + |
| "libraries only have precompiled dynamic libraries:\n") |
| for dynamic_only_root in dynamic_only_roots: |
| message += dynamic_only_root + "\n" |
| fail(message) |
| |
| linker_inputs_count += _add_unused_dynamic_deps(ctx, unused_dynamic_linker_inputs, _add_linker_input_to_dict, topologically_sorted_labels, link_indirect_deps = False) |
| |
| if ctx.attr.experimental_disable_topo_sort_do_not_use_remove_before_7_0: |
| linker_inputs = experimental_remove_before_7_0_linker_inputs |
| else: |
| linker_inputs = _sort_linker_inputs( |
| topologically_sorted_labels, |
| label_to_linker_inputs, |
| linker_inputs_count, |
| ) |
| |
| _throw_linked_but_not_exported_errors(linked_statically_but_not_exported) |
| return (exports, linker_inputs, curr_link_once_static_libs_set.keys(), precompiled_only_dynamic_libraries) |
| |
| def _throw_linked_but_not_exported_errors(error_libs_dict): |
| if not error_libs_dict: |
| return |
| |
| error_builder = ["The following libraries were linked statically by different cc_shared_libraries but not exported:\n"] |
| for cc_shared_library_target, error_libs in error_libs_dict.items(): |
| error_builder.append("cc_shared_library %s:\n" % str(cc_shared_library_target)) |
| for error_lib in error_libs: |
| error_builder.append(" \"%s\",\n" % str(error_lib)) |
| |
| error_builder.append("If you are sure that the previous libraries are exported by the cc_shared_libraries because:\n") |
| error_builder.append(" 1. You have visibility declarations in the source code\n") |
| error_builder.append(" 2. Or you are passing a visibility script to the linker to export symbols from them\n") |
| error_builder.append("then add those libraries to roots or exports_filter for each cc_shared_library.\n") |
| |
| fail("".join(error_builder)) |
| |
| def _same_package_or_above(label_a, label_b): |
| if label_a.workspace_name != label_b.workspace_name: |
| return False |
| package_a_tokenized = label_a.package.split("/") |
| package_b_tokenized = label_b.package.split("/") |
| if len(package_b_tokenized) < len(package_a_tokenized): |
| return False |
| |
| if package_a_tokenized[0] != "": |
| for i in range(len(package_a_tokenized)): |
| if package_a_tokenized[i] != package_b_tokenized[i]: |
| return False |
| |
| return True |
| |
| def _get_deps(ctx): |
| if len(ctx.attr.deps) and len(ctx.attr.roots): |
| fail( |
| "You are using the attribute 'roots' and 'deps'. 'deps' is the " + |
| "new name for the attribute 'roots'. The attribute 'roots' will be" + |
| "removed in the future", |
| attr = "roots", |
| ) |
| |
| deps = ctx.attr.deps |
| if not len(deps): |
| deps = ctx.attr.roots |
| |
| if len(deps) == 0: |
| fail( |
| "'cc_shared_library' must have at least one dependency in 'deps' (or 'roots')", |
| attr = "deps", |
| ) |
| |
| return deps |
| |
| def _build_map_direct_dynamic_dep_to_transitive_dynamic_deps(ctx): |
| all_dynamic_dep_linker_inputs = {} |
| direct_dynamic_dep_to_transitive_dynamic_deps = {} |
| for dep in ctx.attr.dynamic_deps: |
| owner = dep[CcSharedLibraryInfo].linker_input.owner |
| all_dynamic_dep_linker_inputs[owner] = dep[CcSharedLibraryInfo].linker_input |
| transitive_dynamic_dep_labels = [] |
| for dynamic_dep in dep[CcSharedLibraryInfo].dynamic_deps.to_list(): |
| all_dynamic_dep_linker_inputs[dynamic_dep.linker_input.owner] = dynamic_dep.linker_input |
| transitive_dynamic_dep_labels.append(dynamic_dep.linker_input.owner) |
| transitive_dynamic_dep_labels_set = depset(transitive_dynamic_dep_labels, order = "topological") |
| for export in dep[CcSharedLibraryInfo].exports: |
| direct_dynamic_dep_to_transitive_dynamic_deps[export] = transitive_dynamic_dep_labels_set |
| |
| return direct_dynamic_dep_to_transitive_dynamic_deps, all_dynamic_dep_linker_inputs |
| |
| def _add_unused_dynamic_deps(ctx, unused_dynamic_linker_inputs, add_linker_inputs_lambda, topologically_sorted_labels, link_indirect_deps): |
| linker_inputs_count = 0 |
| direct_dynamic_dep_labels = {dep[CcSharedLibraryInfo].linker_input.owner: True for dep in ctx.attr.dynamic_deps} |
| topologically_sorted_labels_set = {label: True for label in topologically_sorted_labels} |
| for dynamic_linker_input_owner, unused_linker_input in unused_dynamic_linker_inputs.items(): |
| should_link_input = (unused_linker_input and |
| (link_indirect_deps or dynamic_linker_input_owner in direct_dynamic_dep_labels)) |
| if should_link_input: |
| add_linker_inputs_lambda( |
| dynamic_linker_input_owner, |
| unused_dynamic_linker_inputs[dynamic_linker_input_owner], |
| ) |
| linker_inputs_count += 1 |
| if dynamic_linker_input_owner not in topologically_sorted_labels_set: |
| topologically_sorted_labels.append(dynamic_linker_input_owner) |
| return linker_inputs_count |
| |
| def _cc_shared_library_impl(ctx): |
| if not cc_common.check_experimental_cc_shared_library(): |
| if len(ctx.attr.static_deps): |
| fail( |
| "This attribute is a no-op and its usage" + |
| " is forbidden after cc_shared_library is no longer experimental. " + |
| "Remove it from every cc_shared_library target", |
| attr = "static_deps", |
| ) |
| if len(ctx.attr.roots): |
| fail( |
| "This attribute has been renamed to 'deps'. Simply rename the" + |
| " attribute on the target.", |
| attr = "roots", |
| ) |
| |
| deps = _get_deps(ctx) |
| |
| cc_toolchain = cc_helper.find_cpp_toolchain(ctx) |
| feature_configuration = cc_common.configure_features( |
| ctx = ctx, |
| cc_toolchain = cc_toolchain, |
| requested_features = ctx.features + ["force_no_whole_archive"], |
| unsupported_features = ctx.disabled_features, |
| ) |
| |
| merged_cc_shared_library_info = _merge_cc_shared_library_infos(ctx) |
| exports_map = _build_exports_map_from_only_dynamic_deps(merged_cc_shared_library_info) |
| for export in deps: |
| # Do not check for overlap between targets matched by the current |
| # rule's exports_filter and what is in exports_map. A library in roots |
| # will have to be linked in statically into the current rule with 100% |
| # guarantee and it will also have to be exported. Therefore, we must |
| # check it's not already exported by a different shared library. On the |
| # other hand, a library in the transitive closure of the current rule |
| # may be matched by the exports_filter but if it's already exported by |
| # a dynamic_dep then it won't be linked statically (therefore not give |
| # an error either) in the current target. The rule will intentionally |
| # not throw an error in these cases. |
| if str(export.label) in exports_map: |
| fail("Trying to export a library already exported by a different shared library: " + |
| str(export.label)) |
| |
| link_once_static_libs_map = _build_link_once_static_libs_map(merged_cc_shared_library_info) |
| |
| (exports, linker_inputs, curr_link_once_static_libs_set, precompiled_only_dynamic_libraries) = _filter_inputs( |
| ctx, |
| feature_configuration, |
| cc_toolchain, |
| deps, |
| exports_map, |
| link_once_static_libs_map, |
| ) |
| |
| linking_context = _create_linker_context(ctx, linker_inputs) |
| |
| user_link_flags = [] |
| for user_link_flag in ctx.attr.user_link_flags: |
| user_link_flags.append(ctx.expand_location(user_link_flag, targets = ctx.attr.additional_linker_inputs)) |
| |
| main_output = None |
| if ctx.attr.shared_lib_name: |
| main_output = ctx.actions.declare_file(ctx.attr.shared_lib_name) |
| |
| win_def_file = None |
| if cc_common.is_enabled(feature_configuration = feature_configuration, feature_name = "targets_windows"): |
| object_files = [] |
| for linker_input in linking_context.linker_inputs.to_list(): |
| for library in linker_input.libraries: |
| if library.pic_static_library != None: |
| if library.pic_objects != None: |
| object_files.extend(library.pic_objects) |
| elif library.static_library != None: |
| if library.objects != None: |
| object_files.extend(library.objects) |
| |
| def_parser = ctx.file._def_parser |
| |
| generated_def_file = None |
| if def_parser != None: |
| generated_def_file = cc_helper.generate_def_file(ctx, def_parser, object_files, ctx.label.name) |
| custom_win_def_file = ctx.file.win_def_file |
| win_def_file = cc_helper.get_windows_def_file_for_linking(ctx, custom_win_def_file, generated_def_file, feature_configuration) |
| |
| additional_inputs = [] |
| additional_inputs.extend(ctx.files.additional_linker_inputs) |
| linking_outputs = cc_common.link( |
| actions = ctx.actions, |
| feature_configuration = feature_configuration, |
| cc_toolchain = cc_toolchain, |
| linking_contexts = [linking_context], |
| user_link_flags = user_link_flags, |
| additional_inputs = additional_inputs, |
| name = ctx.label.name, |
| output_type = "dynamic_library", |
| main_output = main_output, |
| win_def_file = win_def_file, |
| ) |
| |
| runfiles_files = [] |
| if linking_outputs.library_to_link.resolved_symlink_dynamic_library != None: |
| runfiles_files.append(linking_outputs.library_to_link.resolved_symlink_dynamic_library) |
| |
| # This is different to cc_binary(linkshared=1). Bazel never handles the |
| # linking implicitly for a cc_binary(linkshared=1) but it does so for a cc_shared_library, |
| # for which it will use the symlink in the solib directory. If we don't add it, a dependent |
| # linked against it would fail. |
| runfiles_files.append(linking_outputs.library_to_link.dynamic_library) |
| runfiles = ctx.runfiles( |
| files = runfiles_files, |
| ) |
| for dep in ctx.attr.dynamic_deps: |
| runfiles = runfiles.merge(dep[DefaultInfo].data_runfiles) |
| |
| precompiled_only_dynamic_libraries_runfiles = [] |
| for precompiled_dynamic_library in precompiled_only_dynamic_libraries: |
| # precompiled_dynamic_library.dynamic_library could be None if the library to link just contains |
| # an interface library which is valid if the actual library is obtained from the system. |
| if precompiled_dynamic_library.dynamic_library != None: |
| if precompiled_dynamic_library.resolved_symlink_dynamic_library != None: |
| precompiled_only_dynamic_libraries_runfiles.append(precompiled_dynamic_library.resolved_symlink_dynamic_library) |
| else: |
| precompiled_only_dynamic_libraries_runfiles.append(precompiled_dynamic_library.dynamic_library) |
| |
| runfiles = runfiles.merge(ctx.runfiles(files = precompiled_only_dynamic_libraries_runfiles)) |
| |
| for export in deps: |
| exports[str(export.label)] = True |
| |
| if not semantics.get_experimental_link_static_libraries_once(ctx): |
| curr_link_once_static_libs_set = {} |
| |
| library = [] |
| if linking_outputs.library_to_link.resolved_symlink_dynamic_library != None: |
| library.append(linking_outputs.library_to_link.resolved_symlink_dynamic_library) |
| else: |
| library.append(linking_outputs.library_to_link.dynamic_library) |
| |
| interface_library = [] |
| if linking_outputs.library_to_link.resolved_symlink_interface_library != None: |
| interface_library.append(linking_outputs.library_to_link.resolved_symlink_interface_library) |
| elif linking_outputs.library_to_link.interface_library != None: |
| interface_library.append(linking_outputs.library_to_link.interface_library) |
| else: |
| interface_library = library |
| |
| return [ |
| DefaultInfo( |
| files = depset(library), |
| runfiles = runfiles, |
| ), |
| OutputGroupInfo( |
| main_shared_library_output = depset(library), |
| interface_library = depset(interface_library), |
| ), |
| CcSharedLibraryInfo( |
| dynamic_deps = merged_cc_shared_library_info, |
| exports = exports.keys(), |
| link_once_static_libs = curr_link_once_static_libs_set, |
| linker_input = cc_common.create_linker_input( |
| owner = ctx.label, |
| libraries = depset([linking_outputs.library_to_link] + precompiled_only_dynamic_libraries), |
| ), |
| ), |
| ] |
| |
| def _graph_structure_aspect_impl(target, ctx): |
| children = [] |
| |
| attributes = dir(ctx.rule.attr) |
| owners = [ctx.label] |
| if CcSharedLibraryHintInfo in target: |
| attributes = getattr(target[CcSharedLibraryHintInfo], "attributes", dir(ctx.rule.attr)) |
| owners = getattr(target[CcSharedLibraryHintInfo], "owners", [ctx.label]) |
| |
| # Collect graph structure info from any possible deplike attribute. The aspect |
| # itself applies across every deplike attribute (attr_aspects is *), so enumerate |
| # over all attributes and consume GraphNodeInfo if available. |
| for fieldname in attributes: |
| deps = getattr(ctx.rule.attr, fieldname, None) |
| if type(deps) == "list": |
| for dep in deps: |
| if type(dep) == "Target" and GraphNodeInfo in dep: |
| children.append(dep[GraphNodeInfo]) |
| elif type(deps) == "Target" and GraphNodeInfo in deps: |
| children.append(deps[GraphNodeInfo]) |
| |
| # TODO(bazel-team): Add flag to Bazel that can toggle the initialization of |
| # linkable_more_than_once. |
| linkable_more_than_once = False |
| if hasattr(ctx.rule.attr, "tags"): |
| for tag in ctx.rule.attr.tags: |
| if tag == LINKABLE_MORE_THAN_ONCE: |
| linkable_more_than_once = True |
| return [GraphNodeInfo( |
| owners = owners, |
| children = children, |
| linkable_more_than_once = linkable_more_than_once, |
| )] |
| |
| graph_structure_aspect = aspect( |
| attr_aspects = ["*"], |
| required_providers = [[CcInfo], [ProtoInfo], [CcSharedLibraryHintInfo]], |
| required_aspect_providers = [[CcInfo], [CcSharedLibraryHintInfo]], |
| implementation = _graph_structure_aspect_impl, |
| ) |
| |
| cc_shared_library = rule( |
| implementation = _cc_shared_library_impl, |
| attrs = { |
| "additional_linker_inputs": attr.label_list(allow_files = True), |
| "shared_lib_name": attr.string(), |
| "dynamic_deps": attr.label_list(providers = [CcSharedLibraryInfo]), |
| "experimental_disable_topo_sort_do_not_use_remove_before_7_0": attr.bool(default = False), |
| "exports_filter": attr.string_list(), |
| "win_def_file": attr.label(allow_single_file = [".def"]), |
| "roots": attr.label_list(providers = [CcInfo], aspects = [graph_structure_aspect]), |
| "deps": attr.label_list(providers = [CcInfo], aspects = [graph_structure_aspect]), |
| "static_deps": attr.string_list(), |
| "user_link_flags": attr.string_list(), |
| "_def_parser": semantics.get_def_parser(), |
| "_cc_toolchain": attr.label(default = "@" + semantics.get_repo() + "//tools/cpp:current_cc_toolchain"), |
| }, |
| toolchains = cc_helper.use_cpp_toolchain(), |
| fragments = ["cpp"] + semantics.additional_fragments(), |
| ) |
| |
| def cc_shared_library_initializer(**kwargs): |
| """Initializes dynamic_deps_attrs""" |
| if "dynamic_deps" in kwargs and cc_helper.is_non_empty_list_or_select(kwargs["dynamic_deps"], "dynamic_deps"): |
| # Propagate an aspect if dynamic_deps attribute is specified. |
| all_deps = [] |
| if "deps" in kwargs: |
| all_deps.extend(kwargs["deps"]) |
| |
| if "linkshared" not in kwargs or not kwargs["linkshared"]: |
| if "link_extra_lib" in kwargs: |
| all_deps.append(kwargs["link_extra_lib"]) |
| if "malloc" in kwargs: |
| all_deps.append(kwargs["malloc"]) |
| |
| return kwargs | {"_deps_analyzed_by_graph_structure_aspect": all_deps} |
| return kwargs |
| |
| dynamic_deps_attrs = { |
| "dynamic_deps": attr.label_list( |
| allow_files = False, |
| providers = [CcSharedLibraryInfo], |
| ), |
| "_deps_analyzed_by_graph_structure_aspect": attr.label_list( |
| providers = [CcInfo], |
| aspects = [graph_structure_aspect], |
| ), |
| } |
| |
| for_testing_dont_use_check_if_target_under_path = _check_if_target_under_path |
| merge_cc_shared_library_infos = _merge_cc_shared_library_infos |
| build_link_once_static_libs_map = _build_link_once_static_libs_map |
| build_exports_map_from_only_dynamic_deps = _build_exports_map_from_only_dynamic_deps |
| throw_linked_but_not_exported_errors = _throw_linked_but_not_exported_errors |
| separate_static_and_dynamic_link_libraries = _separate_static_and_dynamic_link_libraries |
| sort_linker_inputs = _sort_linker_inputs |
| add_unused_dynamic_deps = _add_unused_dynamic_deps |
