[llvm] r217981 - Internalize common symbols when we can.

[Rafael Espindola]

Author: rafael
Date: Wed Sep 17 15:41:13 2014
New Revision: 217981

URL: http://llvm.org/viewvc/llvm-project?rev=217981&view=rev
Log:
Internalize common symbols when we can.

This fixes pr20974.

Modified:
    llvm/trunk/test/tools/gold/common.ll
    llvm/trunk/tools/gold/gold-plugin.cpp

Modified: llvm/trunk/test/tools/gold/common.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/gold/common.ll?rev=217981&r1=217980&r2=217981&view=diff
==============================================================================
--- llvm/trunk/test/tools/gold/common.ll (original)
+++ llvm/trunk/test/tools/gold/common.ll Wed Sep 17 15:41:13 2014
@@ -8,4 +8,22 @@
 
 @a = common global i8 0, align 8
 
+; Shared library case, we merge @a as common and keep it for the symbol table.
 ; CHECK: @a = common global i16 0, align 8
+
+; RUN: ld -plugin %llvmshlibdir/LLVMgold.so \
+; RUN:    --plugin-opt=emit-llvm \
+; RUN:    %t1.o %t2.o -o %t3.o
+; RUN: llvm-dis %t3.o -o - | FileCheck --check-prefix=EXEC %s
+
+; All IR case, we internalize a after merging.
+; EXEC: @a = internal global i16 0, align 8
+
+; RUN: llc %p/Inputs/common.ll -o %t2.o -filetype=obj
+; RUN: ld -plugin %llvmshlibdir/LLVMgold.so \
+; RUN:    --plugin-opt=emit-llvm \
+; RUN:    %t1.o %t2.o -o %t3.o
+; RUN: llvm-dis %t3.o -o - | FileCheck --check-prefix=MIXED %s
+
+; Mixed ELF and IR. We keep ours as common so the linker will finish the merge.
+; MIXED: @a = common global i8 0, align 8

Modified: llvm/trunk/tools/gold/gold-plugin.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/gold/gold-plugin.cpp?rev=217981&r1=217980&r2=217981&view=diff
==============================================================================
--- llvm/trunk/tools/gold/gold-plugin.cpp (original)
+++ llvm/trunk/tools/gold/gold-plugin.cpp Wed Sep 17 15:41:13 2014
@@ -578,10 +578,12 @@ getModuleForFile(LLVMContext &Context, c
     if (!GV)
       continue; // Asm symbol.
 
-    if (GV->hasCommonLinkage()) {
+    if (Resolution != LDPR_PREVAILING_DEF_IRONLY && GV->hasCommonLinkage()) {
       // Common linkage is special. There is no single symbol that wins the
       // resolution. Instead we have to collect the maximum alignment and size.
       // The IR linker does that for us if we just pass it every common GV.
+      // We still have to keep track of LDPR_PREVAILING_DEF_IRONLY so we
+      // internalize once the IR linker has done its job.
       continue;
     }