Recommit "[ThinLTO] Rename COMDATs for COFF when promoting/renaming COMDAT leader"

Recommit of r352763 with fix for use after free.

llvm-svn: 352770

2 files changed, 42 insertions, 0 deletions

diff --git a/llvm/test/Transforms/FunctionImport/Inputs/comdat.ll b/llvm/test/Transforms/FunctionImport/Inputs/comdat.ll
new file mode 100644
index 00000000000..1df6f25351e
--- /dev/null
+++ b/llvm/test/Transforms/FunctionImport/Inputs/comdat.ll
@@ -0,0 +1,10 @@
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+define void @main() {
+entry:
+  call i8* @lwt_fun()
+  ret void
+}
+
+declare i8* @lwt_fun()
diff --git a/llvm/test/Transforms/FunctionImport/comdat.ll b/llvm/test/Transforms/FunctionImport/comdat.ll
new file mode 100644
index 00000000000..29e8cb538ab
--- /dev/null
+++ b/llvm/test/Transforms/FunctionImport/comdat.ll
@@ -0,0 +1,32 @@
+; Test to ensure that comdat is renamed consistently when comdat leader is
+; promoted and renamed due to an import. Required by COFF.
+
+; REQUIRES: x86-registered-target
+
+; RUN: opt -thinlto-bc -o %t1.bc %s
+; RUN: opt -thinlto-bc -o %t2.bc %S/Inputs/comdat.ll
+; RUN: llvm-lto2 run -save-temps -o %t3 %t1.bc %t2.bc \
+; RUN:          -r %t1.bc,lwt_fun,plx \
+; RUN:          -r %t2.bc,main,plx \
+; RUN:          -r %t2.bc,lwt_fun,
+; RUN: llvm-dis -o - %t3.1.3.import.bc | FileCheck %s
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+; CHECK: $lwt.llvm.[[HASH:[0-9]+]] = comdat any
+$lwt = comdat any
+
+; CHECK: @lwt_aliasee = private unnamed_addr global {{.*}}, comdat($lwt.llvm.[[HASH]])
+@lwt_aliasee = private unnamed_addr global [1 x i8*] [i8* null], comdat($lwt)
+
+; CHECK: @lwt.llvm.[[HASH]] = hidden unnamed_addr alias
+@lwt = internal unnamed_addr alias [1 x i8*], [1 x i8*]* @lwt_aliasee
+
+; Below function should get imported into other module, resulting in @lwt being
+; promoted and renamed.
+define i8* @lwt_fun() {
+  %1 = getelementptr inbounds [1 x i8*], [1 x i8*]* @lwt, i32 0, i32 0
+  %2 = load i8*, i8** %1
+  ret i8* %2
+}