commit c4972610c38bcf8478016572a92843f165d9bfb4
author Nicolas Capens <capn@google.com> Wed Jul 04 09:33:21 2018 -0400
committer Nicolas Capens <nicolascapens@google.com> Thu Jul 05 17:12:45 2018 +0000
tree e43c979d218b255ce96f68e8df4daeaa9c035ef3
parent 6b21ba98f6e43eace87729b96a5443de50e1e0a4

Protect exported symbols from overrides.

While all symbols except for the ones in the version script are hidden,
the exported ones can still be overridden by other libraries which
export the same symbols. Using -fvisibility=protected or the equivalent
attribute fixes this.

Protected visibility used to not work because of
https://bugs.llvm.org//show_bug.cgi?id=30960, but that doesn't appear
to be an issue any more.

Bug chromium:852537
Bug swiftshader:64

Change-Id: Id0b1197b90baa5f5c68bf2aa107d12f8a9856796
Reviewed-on: https://swiftshader-review.googlesource.com/19728
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/OpenGL/libEGL/BUILD.gn

diff --git a/src/OpenGL/libEGL/BUILD.gn b/src/OpenGL/libEGL/BUILD.gn
index 6c2d803..bbbd2eb 100644
--- a/src/OpenGL/libEGL/BUILD.gn
+++ b/src/OpenGL/libEGL/BUILD.gn
@@ -33,7 +33,12 @@
       cflags += [ "-Wno-unused-but-set-variable" ]
     }
 
-    defines += [ "EGLAPI=__attribute__((visibility(\"default\"))) __attribute__((no_sanitize(\"function\")))" ]
+    if (is_mac) {
+      cflags += [ "-fvisibility=protected" ]
+      defines += [ "EGLAPI=__attribute__((no_sanitize(\"function\")))" ]
+    } else {
+      defines += [ "EGLAPI=__attribute__((visibility(\"protected\"))) __attribute__((no_sanitize(\"function\")))" ]
+    }
   }
 }
 

src/OpenGL/libGLESv2/BUILD.gn

diff --git a/src/OpenGL/libGLESv2/BUILD.gn b/src/OpenGL/libGLESv2/BUILD.gn
index 3721fe2..8fb1bad 100644
--- a/src/OpenGL/libGLESv2/BUILD.gn
+++ b/src/OpenGL/libGLESv2/BUILD.gn
@@ -48,9 +48,15 @@
     defines += [
       "__STDC_CONSTANT_MACROS",
       "__STDC_LIMIT_MACROS",
-      "GL_APICALL=__attribute__((visibility(\"default\"))) __attribute__((no_sanitize(\"function\")))",
       "GLAPI=GL_APICALL",
     ]
+
+    if (is_mac) {
+      cflags += [ "-fvisibility=protected" ]
+      defines += [ "GL_APICALL=__attribute__((no_sanitize(\"function\")))" ]
+    } else {
+      defines += [ "GL_APICALL=__attribute__((visibility(\"protected\"))) __attribute__((no_sanitize(\"function\")))" ]
+    }
   }
 }