ThinLTOBitcodeWriter: handle aliases first in filterModule

Summary: This change fixes a "local linkage requires default visibility" assert when attempting to build LLVM with ThinLTO on Windows.

Reviewers: pcc, tejohnson, mehdi_amini

Reviewed By: pcc

Subscribers: llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D31632

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299491 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 4bc7004a0da22bcd6d3555d1d385753f750087ba..393213f0810cd959f1131ed5391b07c615ed77c5 100644 (file)
--- a/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -182,25 +182,6 @@ void simplifyExternals(Module &M) {
 
 void filterModule(
     Module *M, function_ref<bool(const GlobalValue *)> ShouldKeepDefinition) {
-  for (Function &F : *M) {
-    if (ShouldKeepDefinition(&F))
-      continue;
-
-    F.deleteBody();
-    F.setComdat(nullptr);
-    F.clearMetadata();
-  }
-
-  for (GlobalVariable &GV : M->globals()) {
-    if (ShouldKeepDefinition(&GV))
-      continue;
-
-    GV.setInitializer(nullptr);
-    GV.setLinkage(GlobalValue::ExternalLinkage);
-    GV.setComdat(nullptr);
-    GV.clearMetadata();
-  }
-
   for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end();
        I != E;) {
     GlobalAlias *GA = &*I++;
@@ -208,7 +189,7 @@ void filterModule(
       continue;
 
     GlobalObject *GO;
-    if (I->getValueType()->isFunctionTy())
+    if (GA->getValueType()->isFunctionTy())
       GO = Function::Create(cast<FunctionType>(GA->getValueType()),
                             GlobalValue::ExternalLinkage, "", M);
     else
@@ -220,6 +201,25 @@ void filterModule(
     GA->replaceAllUsesWith(GO);
     GA->eraseFromParent();
   }
+
+  for (Function &F : *M) {
+    if (ShouldKeepDefinition(&F))
+      continue;
+
+    F.deleteBody();
+    F.setComdat(nullptr);
+    F.clearMetadata();
+  }
+
+  for (GlobalVariable &GV : M->globals()) {
+    if (ShouldKeepDefinition(&GV))
+      continue;
+
+    GV.setInitializer(nullptr);
+    GV.setLinkage(GlobalValue::ExternalLinkage);
+    GV.setComdat(nullptr);
+    GV.clearMetadata();
+  }
 }
 
 void forEachVirtualFunction(Constant *C, function_ref<void(Function *)> Fn) {

diff --git a/test/Transforms/ThinLTOBitcodeWriter/filter-alias.ll b/test/Transforms/ThinLTOBitcodeWriter/filter-alias.ll
new file mode 100644 (file)
index 0000000..d555ab0
--- /dev/null
+++ b/test/Transforms/ThinLTOBitcodeWriter/filter-alias.ll
@@ -0,0 +1,16 @@
+; RUN: opt -thinlto-bc -o %t %s
+; RUN: llvm-modextract -n 0 -o - %t | llvm-dis | FileCheck --check-prefix=CHECK0 %s
+; RUN: llvm-modextract -n 1 -o - %t | llvm-dis | FileCheck --check-prefix=CHECK1 %s
+; CHECK0: @al = external global i8*
+; CHECK1: @al = unnamed_addr alias i8*,
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+$al = comdat any
+
+@anon = private unnamed_addr constant { [1 x i8*] } { [1 x i8*] [i8* null] }, comdat($al), !type !0
+
+@al = external unnamed_addr alias i8*, getelementptr inbounds ({ [1 x i8*] }, { [1 x i8*] }* @anon, i32 0, i32 0, i32 1)
+
+!0 = !{i64 8, !"?AVA@@"}