Begin reducing the "avoid deps" support for linking down to strictly relaying linking contexts per os/"platform_type" + environment, starting by removing where compilation contexts are propagated and left unused.

Cherry-pick: 14bf4bd

Author: nglevin

apple/internal/BUILD

@@ -344,7 +344,6 @@ bzl_library(
     name = "linking_support",
     srcs = [
         "linking_support.bzl",
-        "multi_arch_binary_support.bzl",
     ],
     visibility = [
         "//apple:__subpackages__",

apple/internal/compilation_support.bzl

@@ -63,6 +63,14 @@ def _build_fully_linked_variable_extensions(*, archive, libs):
     extensions["imported_library_exec_paths"] = []
     return extensions
 
+def _get_static_library_for_linking(library_to_link):
+    if library_to_link.static_library:
+        return library_to_link.static_library
+    elif library_to_link.pic_static_library:
+        return library_to_link.pic_static_library
+    else:
+        return None
+
 def _get_library_for_linking(library_to_link):
     if library_to_link.static_library:
         return library_to_link.static_library
@@ -73,6 +81,53 @@ def _get_library_for_linking(library_to_link):
     else:
         return library_to_link.dynamic_library
 
+def _build_avoid_library_set(avoid_dep_linking_contexts):
+    avoid_library_set = dict()
+    for linking_context in avoid_dep_linking_contexts:
+        for linker_input in linking_context.linker_inputs.to_list():
+            for library_to_link in linker_input.libraries:
+                library_artifact = _get_static_library_for_linking(library_to_link)
+                if library_artifact:
+                    avoid_library_set[library_artifact.short_path] = True
+    return avoid_library_set
+
+def _subtract_linking_contexts(owner, linking_contexts, avoid_dep_linking_contexts):
+    """Subtracts the libraries in avoid_dep_linking_contexts from linking_contexts.
+
+    Args:
+      owner: The label of the target currently being analyzed.
+      linking_contexts: An iterable of CcLinkingContext objects.
+      avoid_dep_linking_contexts: An iterable of CcLinkingContext objects.
+
+    Returns:
+      A CcLinkingContext object.
+    """
+    libraries = []
+    user_link_flags = []
+    additional_inputs = []
+    linkstamps = []
+    avoid_library_set = _build_avoid_library_set(avoid_dep_linking_contexts)
+    for linking_context in linking_contexts:
+        for linker_input in linking_context.linker_inputs.to_list():
+            for library_to_link in linker_input.libraries:
+                library_artifact = _get_library_for_linking(library_to_link)
+                if library_artifact.short_path not in avoid_library_set:
+                    libraries.append(library_to_link)
+            user_link_flags.extend(linker_input.user_link_flags)
+            additional_inputs.extend(linker_input.additional_inputs)
+            linkstamps.extend(linker_input.linkstamps)
+    linker_input = cc_common.create_linker_input(
+        owner = owner,
+        libraries = depset(libraries, order = "topological"),
+        user_link_flags = user_link_flags,
+        additional_inputs = depset(additional_inputs),
+        linkstamps = depset(linkstamps),
+    )
+    return cc_common.create_linking_context(
+        linker_inputs = depset([linker_input]),
+        owner = owner,
+    )
+
 def _libraries_from_linking_context(linking_context):
     libraries = []
     for linker_input in linking_context.linker_inputs.to_list():
@@ -316,4 +371,5 @@ compilation_support = struct(
     # TODO(b/331163513): Move apple_common.compliation_support.build_common_variables here, too.
     register_fully_link_action = _register_fully_link_action,
     register_configuration_specific_link_actions = _register_configuration_specific_link_actions,
+    subtract_linking_contexts = _subtract_linking_contexts,
 )

apple/internal/linking_support.bzl

@@ -33,10 +33,6 @@ load(
     "//apple/internal:intermediates.bzl",
     "intermediates",
 )
-load(
-    "//apple/internal:multi_arch_binary_support.bzl",
-    "subtract_linking_contexts",
-)
 load(
     "//apple/internal:outputs.bzl",
     "outputs",
@@ -91,21 +87,16 @@ def _archive_multi_arch_static_library(
             deps = split_deps[split_transition_key],
         )
 
-        avoid_objc_providers = []
-        avoid_cc_providers = []
         avoid_cc_linking_contexts = []
 
         if len(split_avoid_deps.keys()):
             for dep in split_avoid_deps[split_transition_key]:
-                if apple_common.Objc in dep:
-                    avoid_objc_providers.append(dep[apple_common.Objc])
                 if CcInfo in dep:
-                    avoid_cc_providers.append(dep[CcInfo])
                     avoid_cc_linking_contexts.append(dep[CcInfo].linking_context)
 
         name = ctx.label.name + "-" + cc_toolchain.target_gnu_system_name + "-fl"
 
-        cc_linking_context = subtract_linking_contexts(
+        cc_linking_context = compilation_support.subtract_linking_contexts(
             owner = ctx.label,
             linking_contexts = common_variables.objc_linking_context.cc_linking_contexts,
             avoid_dep_linking_contexts = avoid_cc_linking_contexts,
@@ -239,11 +230,15 @@ def _link_multi_arch_binary(
     avoid_cc_linking_contexts = [dep.linking_context for dep in avoid_cc_infos]
 
     linker_outputs = []
-    cc_infos = []
-    legacy_debug_outputs = {}
 
+    # TODO(b/220185798): Refocus this on cc_linking_context providers, and merge those instead of
+    # CcInfo providers. Refactor the AppleExecutableBinaryInfo and AppleDynamicFrameworkInfo
+    # providers to provide cc_linking_contexts instead of cc_infos as well.
+    cc_infos = []
     cc_infos.extend(avoid_cc_infos)
 
+    legacy_debug_outputs = {}
+
     # $(location...) is only used in one test, and tokenize only affects linkopts in one target
     additional_linker_inputs = getattr(ctx.attr, "additional_linker_inputs", [])
     attr_linkopts = [
@@ -267,16 +262,12 @@ def _link_multi_arch_binary(
         )
 
         cc_infos.append(CcInfo(
-            compilation_context = cc_common.merge_compilation_contexts(
-                compilation_contexts =
-                    common_variables.objc_compilation_context.cc_compilation_contexts,
-            ),
             linking_context = cc_common.merge_linking_contexts(
                 linking_contexts = common_variables.objc_linking_context.cc_linking_contexts,
             ),
         ))
 
-        cc_linking_context = subtract_linking_contexts(
+        cc_linking_context = compilation_support.subtract_linking_contexts(
             owner = ctx.label,
             linking_contexts = common_variables.objc_linking_context.cc_linking_contexts +
                                avoid_cc_linking_contexts,