@@ -37,7 +37,7 @@ GraphNodeInfo = provider(
3737 "Nodes in the graph of shared libraries." ,
3838 fields = {
3939 "children" : "Other GraphNodeInfo from dependencies of this target" ,
40- "label " : "Label of the target visited" ,
40+ "owners " : "Owners of the linker inputs in the targets visited" ,
4141 "linkable_more_than_once" : "Linkable into more than a single cc_shared_library" ,
4242 },
4343)
@@ -54,6 +54,42 @@ CcSharedLibraryInfo = provider(
5454 },
5555)
5656
57+ CcSharedLibraryHintInfo = provider (
58+ doc = """
59+ This provider should be used by rules that provide C++ linker inputs and
60+ want to guide what the cc_shared_library uses. The reason for this may be
61+ for example because the rule is not providing a standard provider like
62+ CcInfo or ProtoInfo or because the rule does not want certain attributes
63+ to be used for linking into shared libraries. It may also be needed if the
64+ rule is using non-standard linker_input.owner names.
65+
66+ Propagation of the cc_shared_library aspect will always happen via all
67+ attributes that provide either CcInfo, ProtoInfo or
68+ CcSharedLibraryHintInfo, the hints control whether the result of that
69+ propagation actually gets used.
70+ """ ,
71+ fields = {
72+ "attributes" : ("[String] - If not set, the aspect will use the result of every " +
73+ "dependency that provides CcInfo, ProtoInfo or CcSharedLibraryHintInfo. " +
74+ "If empty list, the aspect will not use the result of any dependency. If " +
75+ "the list contains a list of attribute names, the aspect will only use the " +
76+ "dependencies corresponding to those attributes as long as they provide CcInfo, " +
77+ "ProtoInfo or CcSharedLibraryHintInfo" ),
78+ "owners" : ("[Label] - cc_shared_library will know which linker_inputs to link based on the owners " +
79+ "field of each linker_input. Most rules will simply use the ctx.label but certain " +
80+ "APIs like cc_common.create_linker_input(owner=) accept any label. " +
81+ "cc_common.create_linking_context_from_compilation_outputs() accepts a `name` which " +
82+ "will then be used to create the owner of the linker_input together with ctx.package." +
83+ "For these cases, since the cc_shared_library cannot guess, the rule author should " +
84+ "provide a hint with the owners of the linker inputs. If the value of owners is not set, then " +
85+ "ctx.label will be used. If the rule author passes a list and they want ctx.label plus some other " +
86+ "label then they will have to add ctx.label explicitly. If you want to use custom owners from C++ " +
87+ "rules keep as close to the original ctx.label as possible, to avoid conflicts with linker_inputs " +
88+ "created by other targets keep the original repository name, the original package name and re-use " +
89+ "the original name as part of your new name, limiting your custom addition to a prefix or suffix." ),
90+ },
91+ )
92+
5793# For each target, find out whether it should be linked statically or
5894# dynamically.
5995def _separate_static_and_dynamic_link_libraries (
@@ -72,16 +108,46 @@ def _separate_static_and_dynamic_link_libraries(
72108 break
73109
74110 node = all_children [i ]
75- node_label = str (node .label )
76111
77- if node_label in seen_labels :
78- continue
79- seen_labels [node_label ] = True
80-
81- if node_label in can_be_linked_dynamically :
82- targets_to_be_linked_dynamically_set [node_label ] = True
83- else :
84- targets_to_be_linked_statically_map [node_label ] = node .linkable_more_than_once
112+ must_add_children = False
113+
114+ # The *_seen variables are used to track a programmatic error and fail
115+ # if it happens. Every value in node.owners presumably corresponds to
116+ # a linker_input in the same exact target. Therefore if we have seen
117+ # any of the owners already, then we must have also seen all the other
118+ # owners in the same node. Viceversa when we haven't seen them yet. If
119+ # both of these values are non-zero after the loop, the most likely
120+ # reason would be a bug in the implementation. It could potentially be
121+ # triggered by users if they use owner labels that do not keep most of
122+ # the ctx.label.package and ctx.label.name which then clash with other
123+ # target's owners (unlikely). For now though if the error is
124+ # triggered, it's reasonable to require manual revision by
125+ # the cc_shared_library implementation owners.
126+ has_owners_seen = False
127+ has_owners_not_seen = False
128+ for owner in node .owners :
129+ # TODO(bazel-team): Do not convert Labels to string to save on
130+ # garbage string allocations.
131+ owner_str = str (owner )
132+
133+ if owner_str in seen_labels :
134+ has_owners_seen = True
135+ continue
136+
137+ has_owners_not_seen = True
138+ seen_labels [owner_str ] = True
139+
140+ if owner_str in can_be_linked_dynamically :
141+ targets_to_be_linked_dynamically_set [owner_str ] = True
142+ else :
143+ targets_to_be_linked_statically_map [owner_str ] = node .linkable_more_than_once
144+ must_add_children = True
145+
146+ if has_owners_seen and has_owners_not_seen :
147+ fail ("Your build has triggered a programmatic error in the cc_shared_library rule. " +
148+ "Please file an issue in https://github.com/bazelbuild/bazel" )
149+
150+ if must_add_children :
85151 all_children .extend (node .children )
86152
87153 return (targets_to_be_linked_statically_map , targets_to_be_linked_dynamically_set )
@@ -209,20 +275,22 @@ def _find_top_level_linker_input_labels(
209275 break
210276
211277 node = nodes_to_check [i ]
212- node_label = str (node .label )
213- if node_label in linker_inputs_to_be_linked_statically_map :
214- has_code_to_link = False
215- for linker_input in linker_inputs_to_be_linked_statically_map [node_label ]:
216- if _contains_code_to_link (linker_input ):
217- top_level_linker_input_labels_set [node_label ] = True
218- has_code_to_link = True
219- break
220-
221- if not has_code_to_link :
222- nodes_to_check .extend (node .children )
223- elif node_label not in targets_to_be_linked_dynamically_set :
224- # This can happen when there was a target in the graph that exported other libraries'
225- # linker_inputs but didn't contribute any linker_input of its own.
278+ must_add_children = False
279+ for owner in node .owners :
280+ owner_str = str (owner )
281+ if owner_str in linker_inputs_to_be_linked_statically_map :
282+ must_add_children = True
283+ for linker_input in linker_inputs_to_be_linked_statically_map [owner_str ]:
284+ if _contains_code_to_link (linker_input ):
285+ top_level_linker_input_labels_set [owner_str ] = True
286+ must_add_children = False
287+ break
288+ elif owner_str not in targets_to_be_linked_dynamically_set :
289+ # This can happen when there was a target in the graph that exported other libraries'
290+ # linker_inputs but didn't contribute any linker_input of its own.
291+ must_add_children = True
292+
293+ if must_add_children :
226294 nodes_to_check .extend (node .children )
227295
228296 return top_level_linker_input_labels_set
@@ -590,10 +658,16 @@ def _cc_shared_library_impl(ctx):
590658def _graph_structure_aspect_impl (target , ctx ):
591659 children = []
592660
661+ attributes = dir (ctx .rule .attr )
662+ owners = [ctx .label ]
663+ if CcSharedLibraryHintInfo in target :
664+ attributes = getattr (target [CcSharedLibraryHintInfo ], "attributes" , dir (ctx .rule .attr ))
665+ owners = getattr (target [CcSharedLibraryHintInfo ], "owners" , [ctx .label ])
666+
593667 # Collect graph structure info from any possible deplike attribute. The aspect
594668 # itself applies across every deplike attribute (attr_aspects is *), so enumerate
595669 # over all attributes and consume GraphNodeInfo if available.
596- for fieldname in dir ( ctx . rule . attr ) :
670+ for fieldname in attributes :
597671 deps = getattr (ctx .rule .attr , fieldname , None )
598672 if type (deps ) == "list" :
599673 for dep in deps :
@@ -609,17 +683,16 @@ def _graph_structure_aspect_impl(target, ctx):
609683 for tag in ctx .rule .attr .tags :
610684 if tag == LINKABLE_MORE_THAN_ONCE :
611685 linkable_more_than_once = True
612-
613686 return [GraphNodeInfo (
614- label = ctx . label ,
687+ owners = owners ,
615688 children = children ,
616689 linkable_more_than_once = linkable_more_than_once ,
617690 )]
618691
619692graph_structure_aspect = aspect (
620693 attr_aspects = ["*" ],
621- required_providers = [[CcInfo ], [ProtoInfo ]],
622- required_aspect_providers = [[CcInfo ]],
694+ required_providers = [[CcInfo ], [ProtoInfo ], [ CcSharedLibraryHintInfo ] ],
695+ required_aspect_providers = [[CcInfo ], [ CcSharedLibraryHintInfo ] ],
623696 implementation = _graph_structure_aspect_impl ,
624697)
625698
@@ -654,3 +727,4 @@ merge_cc_shared_library_infos = _merge_cc_shared_library_infos
654727build_link_once_static_libs_map = _build_link_once_static_libs_map
655728build_exports_map_from_only_dynamic_deps = _build_exports_map_from_only_dynamic_deps
656729throw_linked_but_not_exported_errors = _throw_linked_but_not_exported_errors
730+ separate_static_and_dynamic_link_libraries = _separate_static_and_dynamic_link_libraries
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