[PATCH] D31912: [asan] Give global metadata private linkage.

[Evgeniy Stepanov via Phabricator via llvm-commits]

eugenis created this revision.

Internal linkage preserves names like "__asan_global_foo" which may
account to 2% of unstripped binary size.


Repository:
  rL LLVM

https://reviews.llvm.org/D31912

Files:
  lib/Transforms/Instrumentation/AddressSanitizer.cpp
  test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
  test/Instrumentation/AddressSanitizer/global_metadata_windows.ll


Index: test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
===================================================================
--- test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
+++ test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
@@ -13,7 +13,7 @@
 
 ; CHECK: $dead_global = comdat noduplicates
 ; CHECK: @dead_global = local_unnamed_addr global { i32, [60 x i8] } { i32 42, [60 x i8] zeroinitializer }, comdat, align 32
-; CHECK: @__asan_global_dead_global = internal global { {{.*}} }, section ".ASAN$GL", comdat($dead_global), align 64
+; CHECK: @__asan_global_dead_global = private global { {{.*}} }, section ".ASAN$GL", comdat($dead_global), align 64
 
 @dead_global = local_unnamed_addr global i32 42, align 4
 @mystr = linkonce_odr unnamed_addr constant [5 x i8] c"main\00", comdat, align 1
Index: test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
===================================================================
--- test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
+++ test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
@@ -16,10 +16,10 @@
 
 
 ; Find the metadata for @global:
-; CHECK: [[METADATA:@.+]] = internal global {{.*}} @global {{.*}} section "__DATA,__asan_globals,regular"
+; CHECK: [[METADATA:@.+]] = private global {{.*}} @global {{.*}} section "__DATA,__asan_globals,regular"
 
 ; Find the liveness binder for @global and its metadata:
-; CHECK: @__asan_binder_global = internal global {{.*}} @global {{.*}} [[METADATA]] {{.*}} section "__DATA,__asan_liveness,regular,live_support"
+; CHECK: @__asan_binder_global = private global {{.*}} @global {{.*}} [[METADATA]] {{.*}} section "__DATA,__asan_liveness,regular,live_support"
 
 ; The binder has to be inserted to llvm.compiler.used to avoid being stripped
 ; during LTO.
Index: lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1627,7 +1627,7 @@
                                              StringRef OriginalName) {
   GlobalVariable *Metadata =
       new GlobalVariable(M, Initializer->getType(), false,
-                         GlobalVariable::InternalLinkage, Initializer,
+                         GlobalVariable::PrivateLinkage, Initializer,
                          Twine("__asan_global_") +
                              GlobalValue::getRealLinkageName(OriginalName));
   Metadata->setSection(getGlobalMetadataSection());
@@ -1691,7 +1691,7 @@
         LivenessTy, Initializer->getAggregateElement(0u),
         ConstantExpr::getPointerCast(Metadata, IntptrTy), nullptr);
     GlobalVariable *Liveness = new GlobalVariable(
-        M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
+        M, LivenessTy, false, GlobalVariable::PrivateLinkage, LivenessBinder,
         Twine("__asan_binder_") + G->getName());
     Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
     LivenessGlobals[i] = Liveness;


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