ThinLTO: Resolve linkonce_odr aliases just like functions

This help to streamline the process of handling importing since
we don't need to special case alias everywhere: just like
linkonce_odr function, make sure at least one alias is emitted
by turning it weak.

Differential Revision: http://reviews.llvm.org/D19308

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266958 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 168 insertions, 0 deletions

diff --git a/test/ThinLTO/X86/alias_import.ll b/test/ThinLTO/X86/alias_import.ll
new file mode 100644
index 00000000000..6ba0da0d765
--- /dev/null
+++ b/test/ThinLTO/X86/alias_import.ll
@@ -0,0 +1,168 @@
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/alias_import.ll -o %t2.bc
+; RUN: llvm-lto -thinlto-action=thinlink -o %t.index.bc %t1.bc %t2.bc
+; RUN: llvm-lto -thinlto-action=promote -thinlto-index %t.index.bc %t2.bc -o - | llvm-dis -o - | FileCheck %s --check-prefix=PROMOTE
+; RUN: llvm-lto -thinlto-action=import -thinlto-index %t.index.bc %t1.bc -o - | llvm-dis -o - | FileCheck %s --check-prefix=IMPORT
+
+;
+; Alias can't point to "available_externally", so we can only import an alias
+; when we can import the aliasee with a linkage that won't be
+; available_externally, i.e linkOnceODR. (FIXME this limitation could be lifted)
+; PROMOTE-DAG: @globalfuncAlias = alias void (...), bitcast (void ()* @globalfunc to void (...)*)
+; PROMOTE-DAG: @globalfuncWeakAlias = weak alias void (...), bitcast (void ()* @globalfunc to void (...)*)
+; PROMOTE-DAG: @globalfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @globalfunc to void (...)*)
+; PROMOTE-DAG: @globalfuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @globalfunc to void (...)*)
+; PROMOTE-DAG: @globalfuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @globalfunc to void (...)*)
+; PROMOTE-DAG: @internalfuncAlias = alias void (...), bitcast (void ()* @internalfunc.llvm.0 to void (...)*)
+; PROMOTE-DAG: @internalfuncWeakAlias = weak alias void (...), bitcast (void ()* @internalfunc.llvm.0 to void (...)*)
+; PROMOTE-DAG: @internalfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @internalfunc.llvm.0 to void (...)*)
+; PROMOTE-DAG: @internalfuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @internalfunc.llvm.0 to void (...)*)
+; PROMOTE-DAG: @internalfuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @internalfunc.llvm.0 to void (...)*)
+; PROMOTE-DAG: @linkoncefuncAlias = alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
+; PROMOTE-DAG: @linkoncefuncWeakAlias = weak alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
+; PROMOTE-DAG: @linkoncefuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
+; PROMOTE-DAG: @linkoncefuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
+; PROMOTE-DAG: @linkoncefuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @linkoncefunc to void (...)*)
+; PROMOTE-DAG: @weakfuncAlias = alias void (...), bitcast (void ()* @weakfunc to void (...)*)
+; PROMOTE-DAG: @weakfuncWeakAlias = weak alias void (...), bitcast (void ()* @weakfunc to void (...)*)
+; PROMOTE-DAG: @weakfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @weakfunc to void (...)*)
+; PROMOTE-DAG: @weakfuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @weakfunc to void (...)*)
+; PROMOTE-DAG: @weakfuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @weakfunc to void (...)*)
+; PROMOTE-DAG: @weakODRfuncAlias = alias void (...), bitcast (void ()* @weakODRfunc to void (...)*)
+; PROMOTE-DAG: @weakODRfuncWeakAlias = weak alias void (...), bitcast (void ()* @weakODRfunc to void (...)*)
+; PROMOTE-DAG: @weakODRfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @weakODRfunc to void (...)*)
+; PROMOTE-DAG: @weakODRfuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @weakODRfunc to void (...)*)
+; PROMOTE-DAG: @weakODRfuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @weakODRfunc to void (...)*)
+
+; Only alias to LinkonceODR aliasee can be imported
+; PROMOTE-DAG: @linkonceODRfuncAlias = alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; PROMOTE-DAG: @linkonceODRfuncWeakAlias = weak alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; PROMOTE-DAG: @linkonceODRfuncWeakODRAlias = weak_odr alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; Amongst these that are imported, check that we promote only linkonce->weak
+; PROMOTE-DAG: @linkonceODRfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; PROMOTE-DAG: @linkonceODRfuncLinkonceODRAlias = weak_odr alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+
+; These will be imported, check the linkage/renaming after promotion
+; PROMOTE-DAG: define void @globalfunc()
+; PROMOTE-DAG: define hidden void @internalfunc.llvm.0()
+; PROMOTE-DAG: define linkonce_odr void @linkonceODRfunc()
+; PROMOTE-DAG: define weak_odr void @weakODRfunc()
+; PROMOTE-DAG: define linkonce void @linkoncefunc()
+; PROMOTE-DAG: define weak void @weakfunc()
+
+; On the import side now, verify that aliases to a linkonce_odr are imported, but the weak (never import weak)
+; IMPORT-DAG:  declare void @linkonceODRfuncWeakAlias
+; IMPORT-DAG:  @linkonceODRfuncAlias = alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; IMPORT-DAG:  @linkonceODRfuncLinkonceAlias = linkonce alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; IMPORT-DAG:  @linkonceODRfuncWeakODRAlias = alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; IMPORT-DAG:  @linkonceODRfuncLinkonceODRAlias = linkonce_odr alias void (...), bitcast (void ()* @linkonceODRfunc to void (...)*)
+; IMPORT-DAG:  define linkonce_odr void @linkonceODRfunc()
+
+
+; On the import side, these aliases are not imported (they don't point to a linkonce_odr)
+; IMPORT-DAG: declare void @globalfuncAlias()
+; IMPORT-DAG: declare void @globalfuncWeakAlias()
+; IMPORT-DAG: declare void @globalfuncLinkonceAlias()
+; IMPORT-DAG: declare void @globalfuncWeakODRAlias()
+; IMPORT-DAG: declare void @globalfuncLinkonceODRAlias()
+; IMPORT-DAG: declare void @internalfuncAlias()
+; IMPORT-DAG: declare void @internalfuncWeakAlias()
+; IMPORT-DAG: declare void @internalfuncLinkonceAlias()
+; IMPORT-DAG: declare void @internalfuncWeakODRAlias()
+; IMPORT-DAG: declare void @internalfuncLinkonceODRAlias()
+; IMPORT-DAG: declare void @weakODRfuncAlias()
+; IMPORT-DAG: declare void @weakODRfuncWeakAlias()
+; IMPORT-DAG: declare void @weakODRfuncLinkonceAlias()
+; IMPORT-DAG: declare void @weakODRfuncWeakODRAlias()
+; IMPORT-DAG: declare void @weakODRfuncLinkonceODRAlias()
+; IMPORT-DAG: declare void @linkoncefuncAlias()
+; IMPORT-DAG: declare void @linkoncefuncWeakAlias()
+; IMPORT-DAG: declare void @linkoncefuncLinkonceAlias()
+; IMPORT-DAG: declare void @linkoncefuncWeakODRAlias()
+; IMPORT-DAG: declare void @linkoncefuncLinkonceODRAlias()
+; IMPORT-DAG: declare void @weakfuncAlias()
+; IMPORT-DAG: declare void @weakfuncWeakAlias()
+; IMPORT-DAG: declare void @weakfuncLinkonceAlias()
+; IMPORT-DAG: declare void @weakfuncWeakODRAlias()
+; IMPORT-DAG: declare void @weakfuncLinkonceODRAlias()
+
+
+
+define i32 @main() #0 {
+entry:
+  call void @globalfuncAlias()
+  call void @globalfuncWeakAlias()
+  call void @globalfuncLinkonceAlias()
+  call void @globalfuncWeakODRAlias()
+  call void @globalfuncLinkonceODRAlias()
+
+  call void @internalfuncAlias()
+  call void @internalfuncWeakAlias()
+  call void @internalfuncLinkonceAlias()
+  call void @internalfuncWeakODRAlias()
+  call void @internalfuncLinkonceODRAlias()
+  call void @linkonceODRfuncAlias()
+  call void @linkonceODRfuncWeakAlias()
+  call void @linkonceODRfuncLinkonceAlias()
+  call void @linkonceODRfuncWeakODRAlias()
+  call void @linkonceODRfuncLinkonceODRAlias()
+
+  call void @weakODRfuncAlias()
+  call void @weakODRfuncWeakAlias()
+  call void @weakODRfuncLinkonceAlias()
+  call void @weakODRfuncWeakODRAlias()
+  call void @weakODRfuncLinkonceODRAlias()
+
+  call void @linkoncefuncAlias()
+  call void @linkoncefuncWeakAlias()
+  call void @linkoncefuncLinkonceAlias()
+  call void @linkoncefuncWeakODRAlias()
+  call void @linkoncefuncLinkonceODRAlias()
+
+  call void @weakfuncAlias()
+  call void @weakfuncWeakAlias()
+  call void @weakfuncLinkonceAlias()
+  call void @weakfuncWeakODRAlias()
+  call void @weakfuncLinkonceODRAlias()
+
+  ret i32 0
+}
+
+
+declare void @globalfuncAlias()
+declare void @globalfuncWeakAlias()
+declare void @globalfuncLinkonceAlias()
+declare void @globalfuncWeakODRAlias()
+declare void @globalfuncLinkonceODRAlias()
+
+declare void @internalfuncAlias()
+declare void @internalfuncWeakAlias()
+declare void @internalfuncLinkonceAlias()
+declare void @internalfuncWeakODRAlias()
+declare void @internalfuncLinkonceODRAlias()
+
+declare void @linkonceODRfuncAlias()
+declare void @linkonceODRfuncWeakAlias()
+declare void @linkonceODRfuncLinkonceAlias()
+declare void @linkonceODRfuncWeakODRAlias()
+declare void @linkonceODRfuncLinkonceODRAlias()
+
+declare void @weakODRfuncAlias()
+declare void @weakODRfuncWeakAlias()
+declare void @weakODRfuncLinkonceAlias()
+declare void @weakODRfuncWeakODRAlias()
+declare void @weakODRfuncLinkonceODRAlias()
+
+declare void @linkoncefuncAlias()
+declare void @linkoncefuncWeakAlias()
+declare void @linkoncefuncLinkonceAlias()
+declare void @linkoncefuncWeakODRAlias()
+declare void @linkoncefuncLinkonceODRAlias()
+
+declare void @weakfuncAlias()
+declare void @weakfuncWeakAlias()
+declare void @weakfuncLinkonceAlias()
+declare void @weakfuncWeakODRAlias()
+declare void @weakfuncLinkonceODRAlias()
+
+