Make the bug 24465209 workaround implementation clearer.

Or at least "less intermingled with unrelated configuration".

Change-Id: I2551e58c3a710e0be0efd39cf70fe7f95604f3ca

Author: enh-google

libc/Android.bp

@@ -1,5 +1,3 @@
-// Define the common source files for all the libc instances
-// =========================================================
 package {
     default_applicable_licenses: ["bionic_libc_license"],
 }
@@ -114,6 +112,26 @@ cc_defaults {
     tidy_disabled_srcs: ["upstream-*/**/*.c"],
 }
 
+// Workaround for b/24465209.
+// We're unlikely to be able to remove this before we just
+// remove ILP32 support completely.
+// Note that we also still have `pack_relocations: false`
+// for both libc and libm, even on LP64.
+// ========================================================
+cc_defaults {
+    name: "bug_24465209_workaround",
+    arch: {
+        arm: {
+            pack_relocations: false,
+            ldflags: ["-Wl,--hash-style=both"],
+        },
+        x86: {
+            pack_relocations: false,
+            ldflags: ["-Wl,--hash-style=both"],
+        }
+    },
+}
+
 // Defaults for native allocator libs/includes to make it
 // easier to change.
 // ========================================================
@@ -1529,6 +1547,7 @@ cc_defaults {
     defaults: [
         "libc_defaults",
         "libc_native_allocator_defaults",
+        "bug_24465209_workaround",
     ],
     name: "libc_library_defaults",
     product_variables: {
@@ -1586,10 +1605,7 @@ cc_defaults {
 
     arch: {
         arm: {
-            // TODO: This is to work around b/24465209. Remove after root cause is fixed.
-            pack_relocations: false,
             ldflags: [
-                "-Wl,--hash-style=both",
                 // Since we are preserving the debug_frame, do not compress
                 // in this case to make unwinds as fast as possible.
                 "-Wl,--compress-debug-sections=none",
@@ -1633,10 +1649,6 @@ cc_defaults {
             },
         },
         x86: {
-            // TODO: This is to work around b/24465209. Remove after root cause is fixed.
-            pack_relocations: false,
-            ldflags: ["-Wl,--hash-style=both"],
-
             version_script: ":libc.x86.map",
             no_libcrt: true,
 
@@ -1916,7 +1928,10 @@ cc_library_headers {
 // ========================================================
 
 cc_library {
-    defaults: ["libc_defaults"],
+    defaults: [
+        "libc_defaults",
+        "bug_24465209_workaround",
+    ],
     include_dirs: ["bionic/libstdc++/include"],
     srcs: [
         "bionic/__cxa_guard.cpp",
@@ -1941,12 +1956,8 @@ cc_library {
         },
     },
 
-    //TODO (dimitry): This is to work around b/24465209. Remove after root cause is fixed
     arch: {
         arm: {
-            // TODO: This is to work around b/24465209. Remove after root cause is fixed.
-            pack_relocations: false,
-            ldflags: ["-Wl,--hash-style=both"],
             version_script: ":libstdc++.arm.map",
         },
         arm64: {
@@ -1956,8 +1967,6 @@ cc_library {
             version_script: ":libstdc++.riscv64.map",
         },
         x86: {
-            pack_relocations: false,
-            ldflags: ["-Wl,--hash-style=both"],
             version_script: ":libstdc++.x86.map",
         },
         x86_64: {

libm/Android.bp

@@ -21,7 +21,10 @@ license {
 
 cc_library {
     name: "libm",
-    defaults: ["linux_bionic_supported"],
+    defaults: [
+        "linux_bionic_supported",
+        "bug_24465209_workaround",
+    ],
     ramdisk_available: true,
     vendor_ramdisk_available: true,
     recovery_available: true,
@@ -282,8 +285,6 @@ cc_library {
                 "upstream-freebsd/lib/msun/src/s_ceilf.c",
             ],
             instruction_set: "arm",
-            pack_relocations: false,
-            ldflags: ["-Wl,--hash-style=both"],
             version_script: ":libm.arm.map",
             no_libcrt: true,
             shared: {
@@ -368,11 +369,9 @@ cc_library {
                 "upstream-freebsd/lib/msun/src/s_truncf.c",
             ],
             local_include_dirs: ["i387"],
-            pack_relocations: false,
             // The x86 ABI doesn't include this, which is needed for the
             // roundss/roundsd instructions that we've used since Android M.
             cflags: ["-msse4.1"],
-            ldflags: ["-Wl,--hash-style=both"],
             version_script: ":libm.x86.map",
         },