From ec5553352f2f661d39ac4cf665dd9b3c779e614c Mon Sep 17 00:00:00 2001
From: Googler <noreply@google.com>
Date: Fri, 15 Jan 2021 07:16:11 -0800
Subject: [PATCH] Remove support for "nodeps" dynamic libraries on Apple
 platforms.

Any such usage was only accidentally working due to -undefined dynamic_lookup.
That flag only works on Darwin (macOS) at all.

But even there, TLS can cause undefined symbols with these "nodeps" libraries.

Fundamentally, Mach-O's two-level namespacing makes this infeasible.

https://github.com/bazelbuild/bazel/issues/4341

Closes #4341.

PiperOrigin-RevId: 352002776
---
 src/test/shell/bazel/cc_integration_test.sh    |  8 ++++++++
 .../bazel/tags_propagation_native_test.sh      | 18 ++++++++++--------
 .../shell/integration/configured_query_test.sh |  2 ++
 tools/cpp/cc_toolchain_config.bzl              |  1 -
 tools/osx/crosstool/cc_toolchain_config.bzl    |  3 ---
 5 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/test/shell/bazel/cc_integration_test.sh b/src/test/shell/bazel/cc_integration_test.sh
index 7b9756ae423d2c..f08a91b58ff9e7 100755
--- a/src/test/shell/bazel/cc_integration_test.sh
+++ b/src/test/shell/bazel/cc_integration_test.sh
@@ -660,6 +660,10 @@ EOF
 }
 
 function test_aspect_accessing_args_link_action_with_tree_artifact() {
+  # This test assumes the presence of "nodeps" dynamic libraries, which do not
+  # function on Apple platforms.
+  [ "$PLATFORM" != "darwin" ] || return 0
+
   local package="${FUNCNAME[0]}"
   mkdir -p "${package}"
   cat > "${package}/makes_tree_artifacts.sh" <<EOF
@@ -739,6 +743,10 @@ EOF
 }
 
 function test_directory_arg_compile_action() {
+  # This test assumes the presence of "nodeps" dynamic libraries, which do not
+  # function on Apple platforms.
+  [ "$PLATFORM" != "darwin" ] || return 0
+
   local package="${FUNCNAME[0]}"
   mkdir -p "${package}"
 
diff --git a/src/test/shell/bazel/tags_propagation_native_test.sh b/src/test/shell/bazel/tags_propagation_native_test.sh
index a48ee2257b098b..d6395d8606accd 100755
--- a/src/test/shell/bazel/tags_propagation_native_test.sh
+++ b/src/test/shell/bazel/tags_propagation_native_test.sh
@@ -55,14 +55,16 @@ EOF
   assert_contains "local:" output1
   assert_contains "no-cache:" output1
   assert_contains "no-remote:" output1
-
-  bazel aquery --experimental_allow_tags_propagation 'mnemonic("CppLink", outputs(".*/libtest.so", //test:test))' > output1 2> $TEST_log \
-      || fail "should have generated output successfully"
-
-  assert_contains "ExecutionInfo: {" output1
-  assert_contains "local:" output1
-  assert_contains "no-cache:" output1
-  assert_contains "no-remote:" output1
+  if [ "${PLATFORM}" != "darwin" ]; then
+    # Darwin does not support implicit "nodeps" shared libraries.
+    bazel aquery --experimental_allow_tags_propagation 'mnemonic("CppLink", outputs(".*/libtest.so", //test:test))' > output1 2> $TEST_log \
+        || fail "should have generated output successfully"
+
+    assert_contains "ExecutionInfo: {" output1
+    assert_contains "local:" output1
+    assert_contains "no-cache:" output1
+    assert_contains "no-remote:" output1
+  fi
 }
 
 function test_cc_binary_tags_propagated() {
diff --git a/src/test/shell/integration/configured_query_test.sh b/src/test/shell/integration/configured_query_test.sh
index 128a270097609b..7c716d6d461c29 100755
--- a/src/test/shell/integration/configured_query_test.sh
+++ b/src/test/shell/integration/configured_query_test.sh
@@ -1122,6 +1122,8 @@ EOF
 
   if "$is_windows"; then
     assert_contains "cclib.lib" output
+  elif is_darwin; then
+    assert_contains "libcclib.a" output
   else
     assert_contains "libcclib.a" output
     assert_contains "libcclib.so" output
diff --git a/tools/cpp/cc_toolchain_config.bzl b/tools/cpp/cc_toolchain_config.bzl
index f4748365fd3c0a..807e769ae8dafc 100644
--- a/tools/cpp/cc_toolchain_config.bzl
+++ b/tools/cpp/cc_toolchain_config.bzl
@@ -1159,7 +1159,6 @@ def _impl(ctx):
         features = [
             default_compile_flags_feature,
             default_link_flags_feature,
-            supports_dynamic_linker_feature,
             supports_pic_feature,
             objcopy_embed_flags_feature,
             dbg_feature,
diff --git a/tools/osx/crosstool/cc_toolchain_config.bzl b/tools/osx/crosstool/cc_toolchain_config.bzl
index 21eac5aa09ac4a..79616b2062522e 100644
--- a/tools/osx/crosstool/cc_toolchain_config.bzl
+++ b/tools/osx/crosstool/cc_toolchain_config.bzl
@@ -4734,8 +4734,6 @@ def _impl(ctx):
         ],
     )
 
-    supports_dynamic_linker_feature = feature(name = "supports_dynamic_linker", enabled = True)
-
     objc_actions_feature = feature(
         name = "objc_actions",
         implies = [
@@ -6243,7 +6241,6 @@ def _impl(ctx):
             linker_param_file_feature,
             compiler_input_flags_feature,
             compiler_output_flags_feature,
-            supports_dynamic_linker_feature,
             objcopy_embed_flags_feature,
             dynamic_linking_mode_feature,
             set_install_name,