llvm-mirror/test/ThinLTO/X86/funcimport_alwaysinline.ll
Fangrui Song d41ca54775 [ThinLTO] Drop dso_local if a GlobalVariable satisfies isDeclarationForLinker()
dso_local leads to direct access even if the definition is not within this compilation unit (it is
still in the same linkage unit). On ELF, such a relocation (e.g. R_X86_64_PC32) referencing a
STB_GLOBAL STV_DEFAULT object can cause a linker error in a -shared link.

If the linkage is changed to available_externally, the dso_local flag should be dropped, so that no
direct access will be generated.

The current behavior is benign, because -fpic does not assume dso_local
(clang/lib/CodeGen/CodeGenModule.cpp:shouldAssumeDSOLocal).
If we do that for -fno-semantic-interposition (D73865), there will be an
R_X86_64_PC32 linker error without this patch.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D74751
2020-04-07 15:46:01 -07:00

27 lines
1.1 KiB
LLVM

; RUN: opt -module-summary %s -o %t1.bc
; RUN: opt -module-summary %p/Inputs/funcimport_alwaysinline.ll -o %t2.bc
; RUN: llvm-lto2 run %t1.bc %t2.bc -o %t.o -save-temps \
; RUN: -r=%t1.bc,foo,plx \
; RUN: -r=%t2.bc,main,plx \
; RUN: -r=%t2.bc,foo,l \
; RUN: -import-instr-limit=0
; RUN: llvm-dis %t.o.2.3.import.bc -o - | FileCheck %s --check-prefix=CHECK1
; RUN: llvm-dis %t.o.index.bc -o - | FileCheck %s --check-prefix=CHECK2
; foo() being always_inline should be imported irrespective of the
; instruction limit
; CHECK1: define available_externally void @foo()
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: alwaysinline nounwind uwtable
define void @foo() #0 {
entry:
ret void
}
attributes #0 = { alwaysinline nounwind uwtable }
; CHECK2: ^2 = gv: (guid: {{.*}}, summaries: (function: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 1, dsoLocal: 1, canAutoHide: 0), insts: 1, funcFlags: (readNone: 0, readOnly: 0, noRecurse: 0, returnDoesNotAlias: 0, noInline: 0, alwaysInline: 1))))