Build with -Bsymbolic to prevent symbol preemption

The CMake build was already using -fvisibility=protected, which has the same effect but uses duplicate symbol entries for internal/external use. Bug: b/148240133 Change-Id: I8069a1b293a6ec0604be32179ed591ffaa645ed7 Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/41648 Presubmit-Ready: Nicolas Capens <nicolascapens@google.com> Tested-by: Nicolas Capens <nicolascapens@google.com> Reviewed-by: Antonio Maiorano <amaiorano@google.com>

Build with -Bsymbolic to prevent symbol preemption
e3621dca · Nicolas Capens · Nicolas Capens · da659b37 · e3621dca · e3621dca
Commit e3621dca authored Feb 25, 2020 by Nicolas Capens Committed by Nicolas Capens Feb 26, 2020
Hide whitespace changes
Inline Side-by-side

Showing with 15 additions and 4 deletions

CMakeLists.txt CMakeLists.txt +3 -2

Android.bp src/Android.bp +6 -0

BUILD.gn src/Vulkan/BUILD.gn +6 -2

No files found.
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -293,8 +293,9 @@ macro(set_shared_library_export_map TARGET DIR)
        set_property(TARGET ${TARGET} APPEND_STRING PROPERTY LINK_FLAGS " -Wl,--version-script=${DIR}/${TARGET}.lds")
        set_property(TARGET ${TARGET} APPEND_STRING PROPERTY LINK_DEPENDS "${DIR}/${TARGET}.lds;")
-        # Don't allow symbols to be overridden by another module.
+        # -Bsymbolic binds symbol references to their global definitions within
-        set_property(TARGET ${TARGET} APPEND_STRING PROPERTY COMPILE_FLAGS " -fvisibility=protected")
+        # a shared object, thereby preventing symbol preemption.
+        set_property(TARGET ${TARGET} APPEND_STRING PROPERTY COMPILE_FLAGS "  -Wl,-Bsymbolic")
        if(ARCH STREQUAL "mipsel" OR ARCH STREQUAL "mips64el")
          # MIPS supports sysv hash-style only.

--- a/src/Android.bp
+++ b/src/Android.bp
@@ -555,6 +555,12 @@ cc_defaults {
        "-Wno-non-virtual-dtor",
    ],
+    ldflags: [
+        // -Bsymbolic binds symbol references to their global definitions within
+        // a shared object, thereby preventing symbol preemption.
+        "-Wl,-Bsymbolic",
+    ],
    local_include_dirs: [ "Vulkan" ],
    version_script: "Vulkan/android_vk_swiftshader.lds",

--- a/src/Vulkan/BUILD.gn
+++ b/src/Vulkan/BUILD.gn
@@ -158,8 +158,12 @@ swiftshader_shared_library("swiftshader_libvulkan") {
    inputs = [
      "vk_swiftshader.lds",
    ]
-    ldflags = [ "-Wl,--version-script=" +
+    ldflags = [
-                rebase_path("vk_swiftshader.lds", root_build_dir) ]
+      # -Bsymbolic binds symbol references to their global definitions within
+      # a shared object, thereby preventing symbol preemption.
+      "-Wl,-Bsymbolic",
+      "-Wl,--version-script=" +
+          rebase_path("vk_swiftshader.lds", root_build_dir) ]
  }
  deps = [