llvm-6502/test/Linker/global_ctors.ll
Duncan P. N. Exon Smith 49135bb76c Don't upgrade global constructors when reading bitcode
An optional third field was added to `llvm.global_ctors` (and
`llvm.global_dtors`) in r209015.  Most of the code has been changed to
deal with both versions of the variables.  Users of the C API might
create either version, the helper functions in LLVM create the two-field
version, and clang now creates the three-field version.

However, the BitcodeReader was changed to always upgrade to the
three-field version.  This created an unnecessary inconsistency in the
IR before/after serializing to bitcode.

This commit resolves the inconsistency by making the third field truly
optional (and not upgrading in the bitcode reader).  Since `llvm-link`
was relying on this upgrade code, rather than deleting it I've moved it
into `ModuleLinker`, where it upgrades these arrays as necessary to
resolve inconsistencies between modules.

The ideal resolution would be to remove the 2-field version and make the
third field required.  I filed PR20506 to track that.

I changed `test/Bitcode/upgrade-global-ctors.ll` to a negative test and
duplicated the `llvm-link` check in `test/Linker/global_ctors.ll` to
check both upgrade directions.

Since I came across this as part of PR5680 (serializing use-list order),
I've also added the missing `verify-uselistorder` RUN line to
`test/Bitcode/metadata-2.ll`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215457 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-12 16:46:37 +00:00

31 lines
1.3 KiB
LLVM

; RUN: llvm-as %s -o %t.new.bc
; RUN: llvm-link %t.new.bc %S/Inputs/old_global_ctors.3.4.bc | llvm-dis | FileCheck %s
; RUN: llvm-link %S/Inputs/old_global_ctors.3.4.bc %t.new.bc | llvm-dis | FileCheck %s
; old_global_ctors.3.4.bc contains the following LLVM IL, assembled into
; bitcode by llvm-as from 3.4. It uses a two element @llvm.global_ctors array.
; ---
; declare void @a_global_ctor()
; declare void @b_global_ctor()
;
; @llvm.global_ctors = appending global [2 x { i32, void ()* } ] [
; { i32, void ()* } { i32 65535, void ()* @a_global_ctor },
; { i32, void ()* } { i32 65535, void ()* @b_global_ctor }
; ]
; ---
declare void @c_global_ctor()
declare void @d_global_ctor()
@llvm.global_ctors = appending global [2 x { i32, void ()*, i8* } ] [
{ i32, void ()*, i8* } { i32 65535, void ()* @c_global_ctor, i8* null },
{ i32, void ()*, i8* } { i32 65535, void ()* @d_global_ctor, i8* null }
]
; CHECK: @llvm.global_ctors = appending global [4 x { i32, void ()*, i8* }] [
; CHECK-DAG: { i32, void ()*, i8* } { i32 65535, void ()* @a_global_ctor, i8* null }
; CHECK-DAG: { i32, void ()*, i8* } { i32 65535, void ()* @b_global_ctor, i8* null }
; CHECK-DAG: { i32, void ()*, i8* } { i32 65535, void ()* @c_global_ctor, i8* null }
; CHECK-DAG: { i32, void ()*, i8* } { i32 65535, void ()* @d_global_ctor, i8* null }
; CHECK: ]