[lld] [lld][NFC] Precommit test for ld -r links FatLTO PIC objects (PR #92817)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lld

@llvm/pr-subscribers-lld-elf

Author: Paul Kirth (ilovepi)

<details>
<summary>Changes</summary>

Currently, with PIC relocatable links, FatLTO sections are treated as orphan
sections and incorrectly concatenated together. This test verifies the current
behavior, but should be fixed to either merge those sections into a single llvm
module, similar to what `llvm-link` would produce, or to drop them altogether.


---
Full diff: https://github.com/llvm/llvm-project/pull/92817.diff


1 Files Affected:

- (modified) lld/test/ELF/fatlto/fatlto.test (+41) 


``````````diff
diff --git a/lld/test/ELF/fatlto/fatlto.test b/lld/test/ELF/fatlto/fatlto.test
index edf4ef2da2b88..2b9c41d5f5587 100644
--- a/lld/test/ELF/fatlto/fatlto.test
+++ b/lld/test/ELF/fatlto/fatlto.test
@@ -49,6 +49,25 @@
 ; RUN: ld.lld -o %t/foo-fatLTO.archive %t/a.a %t/main-LTO.bc --fat-lto-objects
 ; RUN: cmp %t/foo-fatLTO.archive %t/foo-LTO
 
+;; Test FatLTO works with relocatable links using PIC objects
+;; Currently, with PIC relocatable links, FatLTO sections are treated as
+;; orphan sections and incorrectly concatenated together. This test verifies
+;; the current behavior, but should be fixed to either merge those sections
+;; correctly, or to drop them altogether.
+; RUN: opt < %t/a-LTO.ll -passes="embed-bitcode<thinlto;emit-summary>" | llc --relocation-model=pic --filetype=obj -o %t/a-fat-pic.o
+; RUN: llvm-readobj -S %t/a-fat-pic.o | FileCheck --check-prefix=HAS_LLVM_LTO %s
+
+; RUN: opt < %t/b-LTO.ll -passes="embed-bitcode<thinlto;emit-summary>" | llc --relocation-model=pic --filetype=obj -o %t/b-fat-pic.o
+; RUN: llvm-readobj -S %t/b-fat-pic.o | FileCheck --check-prefix=HAS_LLVM_LTO %s
+
+; RUN: llvm-ar rcs %t/fat.archive %t/a-fat-pic.o %t/b-fat-pic.o
+; RUN: llvm-readobj -S %t/fat.pic.archive | FileCheck --check-prefix=HAS_LLVM_LTO %s
+
+; RUN: ld.lld --whole-archive %t/fat.pic.archive -r -o %t/fat-relocatable.o
+; RUN: llvm-readobj -S %t/fat-pic-relocatable.o | FileCheck --check-prefix=HAS_LLVM_LTO %s
+
+; HAS_LLVM_LTO: Name: .llvm.lto
+
 ;--- a-LTO.ll
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
@@ -71,6 +90,28 @@ attributes #0 = { noinline nounwind uwtable }
 !5 = !{i32 1, !"ThinLTO", i32 0}
 !6 = !{i32 1, !"EnableSplitLTOUnit", i32 1}
 
+;--- b-LTO.ll
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline nounwind uwtable
+define dso_local i32 @foo() #0 {
+entry:
+  ret i32 0
+}
+
+attributes #0 = { noinline nounwind uwtable }
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 7, !"PIC Level", i32 2}
+!2 = !{i32 7, !"PIE Level", i32 2}
+!3 = !{i32 7, !"uwtable", i32 2}
+!4 = !{i32 7, !"frame-pointer", i32 2}
+!5 = !{i32 1, !"ThinLTO", i32 0}
+!6 = !{i32 1, !"EnableSplitLTOUnit", i32 1}
+
 ;--- main-LTO.ll
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"

``````````

</details>


https://github.com/llvm/llvm-project/pull/92817