llvm/test/Bitcode/thinlto-alias.ll
Teresa Johnson 9488ca4c3f [ThinLTO] Auto-hide prevailing linkonce_odr only when all copies eligible
Summary:
We hit undefined references building with ThinLTO when one source file
contained explicit instantiations of a template method (weak_odr) but
there were also implicit instantiations in another file (linkonce_odr),
and the latter was the prevailing copy. In this case the symbol was
marked hidden when the prevailing linkonce_odr copy was promoted to
weak_odr. It led to unsats when the resulting shared library was linked
with other code that contained a reference (expecting to be resolved due
to the explicit instantiation).

Add a CanAutoHide flag to the GV summary to allow the thin link to
identify when all copies are eligible for auto-hiding (because they were
all originally linkonce_odr global unnamed addr), and only do the
auto-hide in that case.

Most of the changes here are due to plumbing the new flag through the
bitcode and llvm assembly, and resulting test changes. I augmented the
existing auto-hide test to check for this situation.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, dexonsmith, arphaman, dang, llvm-commits, steven_wu, wmi

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59709

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360466 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-10 20:08:24 +00:00

64 lines
3.2 KiB
LLVM

; Test to check the callgraph in summary
; RUN: opt -module-summary %s -o %t.o
; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
; RUN: opt -module-summary %p/Inputs/thinlto-alias.ll -o %t2.o
; RUN: llvm-dis -o - %t2.o | FileCheck %s --check-prefix=DIS
; Round trip it through llvm-as
; RUN: llvm-dis -o - %t2.o | llvm-as -o - | llvm-dis -o - | FileCheck %s --check-prefix=DIS
; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
; RUN: llvm-dis -o - %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED-DIS
; Round trip it through llvm-as
; RUN: llvm-dis -o - %t3.thinlto.bc | llvm-as -o - | llvm-dis -o - | FileCheck %s --check-prefix=COMBINED-DIS
; CHECK: <SOURCE_FILENAME
; "main"
; CHECK-NEXT: <FUNCTION op0=0 op1=4
; "analias"
; CHECK-NEXT: <FUNCTION op0=4 op1=7
; CHECK: <GLOBALVAL_SUMMARY_BLOCK
; CHECK-NEXT: <VERSION
; CHECK-NEXT: <FLAGS
; See if the call to func is registered.
; The value id 1 matches the second FUNCTION record above.
; CHECK-NEXT: <PERMODULE {{.*}} op6=1/>
; CHECK-NEXT: </GLOBALVAL_SUMMARY_BLOCK>
; CHECK: <STRTAB_BLOCK
; CHECK-NEXT: blob data = 'mainanalias{{.*}}'
; COMBINED: <GLOBALVAL_SUMMARY_BLOCK
; COMBINED-NEXT: <VERSION
; COMBINED-NEXT: <FLAGS
; See if the call to analias is registered, using the expected value id.
; COMBINED-NEXT: <VALUE_GUID op0=[[ALIASID:[0-9]+]] op1=-5751648690987223394/>
; COMBINED-NEXT: <VALUE_GUID
; COMBINED-NEXT: <VALUE_GUID op0=[[ALIASEEID:[0-9]+]] op1=-1039159065113703048/>
; COMBINED-NEXT: <COMBINED {{.*}} op8=[[ALIASID]]/>
; COMBINED-NEXT: <COMBINED {{.*}}
; COMBINED-NEXT: <COMBINED_ALIAS {{.*}} op3=[[ALIASEEID]]
; COMBINED-NEXT: </GLOBALVAL_SUMMARY_BLOCK
; ModuleID = 'thinlto-function-summary-callgraph.ll'
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: nounwind uwtable
define i32 @main() {
entry:
call void (...) @analias()
ret i32 0
}
declare void @analias(...)
; DIS: ^0 = module: (path: "{{.*}}", hash: (0, 0, 0, 0, 0))
; DIS: ^1 = gv: (name: "analias", summaries: (alias: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), aliasee: ^2))) ; guid = 12695095382722328222
; DIS: ^2 = gv: (name: "aliasee", summaries: (function: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 1))) ; guid = 17407585008595848568
; COMBINED-DIS: ^0 = module: (path: "{{.*}}thinlto-alias.ll.tmp.o", hash: (0, 0, 0, 0, 0))
; COMBINED-DIS: ^1 = module: (path: "{{.*}}thinlto-alias.ll.tmp2.o", hash: (0, 0, 0, 0, 0))
; COMBINED-DIS: ^2 = gv: (guid: 12695095382722328222, summaries: (alias: (module: ^1, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), aliasee: ^4)))
; COMBINED-DIS: ^3 = gv: (guid: 15822663052811949562, summaries: (function: (module: ^0, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 2, calls: ((callee: ^2)))))
; COMBINED-DIS: ^4 = gv: (guid: 17407585008595848568, summaries: (function: (module: ^1, flags: (linkage: external, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 1)))