[lld][ELF][test] Add additional LTO testing

[jhenderson]

Summary

The additional testing is testing we previously had in a downstream testsuite.

[grimar]

lld/test/ELF/lto/archive-mixed.ll

26 ↗

(On Diff #292453)

nit: in the llvm-ar block above, a.bc.b.o.a follows the a.bc.b.bc.a. I'd suggest to keep the order here.

lld/test/ELF/lto/undef-mixed2.s

3 ↗

(On Diff #292453)

I'd put "REQUIRES" on the first line.

5 ↗

(On Diff #292453)

Any reason not to use split-file instead of adding a new input?

lld/test/ELF/lto/wrap-2.ll

2–43

Probably worth adding a general comment about what this test case validates?

5

%t.bc.bc.so looks a bit strange, though I see why you name it like this.
Do %t.bc-bc.so reads better? (the same for other .so).

16

Perhaps %t2.o, since you have %t1.o already?

[jhenderson]

Address @grimar's comments (added additional comments, used split-file, renamed various things). Also renamed two tests using split-file which are not specifically .ll or .s.

lld/test/ELF/lto/undef-mixed2.s

5 ↗

(On Diff #292453)

That's what happens when you try to write/copy tests whilst half asleep. Mostly, it was becuase this test was derived from undef-mixed.s originally. I'm happy to use split-file though.

[grimar]

LGTM. Worth waiting for @MaskRay or someone else opinion too.

[jhenderson]

In D87824#2279183, @grimar wrote:

LGTM. Worth waiting for @MaskRay or someone else opinion too.

Will do. Thanks for the quick feedback.

[psmith]

LGTM too, thanks for adding the tests.

[MaskRay]

I have a suggestion to a test. If you exclude lto/wrap-2.ll from this patch, it will look good to me.

lld/test/ELF/lto/internalize-basic.ll

14

You can enhance the test by deleting hidden. The important property is isUsedInRegularObj, not visibility.

lld/test/ELF/lto/wrap-2.ll

2–43

Is it related to D85782? My feeling is https://reviews.llvm.org/D85782#2211636

I think we need to be careful making this promise. This is not intentionally guaranteed.

[jhenderson]

Remove hidden.

lld/test/ELF/lto/internalize-basic.ll

14

Done, but I noticed that foo is also hidden. Any idea why?

lld/test/ELF/lto/wrap-2.ll

2–43

No, I don't think so, unless I misunderstood something. D85782 is for intra-module references, i.e. where the reference and definition are within the same input file. This test is about inter-module references, i.e. references between different modules.

The cases I've actually added are [Thin]LTO + native object, where one or other defines the symbol to be wrapped (as well as the wrapped version), and the other references that symbol. My understanding is that this behaviour should be stable.

[MaskRay]

LGTM.

lld/test/ELF/lto/internalize-basic.ll

14

I think that is fine. It adds some variants to further demonstrate the property after the main property has been tested.

[MaskRay]

lld/test/ELF/lto/wrap-2.ll

2–43

Thanks. Inter-module references via --wrap are something we should make a promise. Intra-module --wrap is fragile (not supported by GCC and even in LLVM's LTO framework it is fragile as well).

[jhenderson]

Thanks for the reviews. I'll land this later today.

lld/test/ELF/lto/wrap-2.ll

2–43

Makes sense to me.

lld/test/ELF/lto/archive-mixed.test

+; REQUIRES: x86
+;; Show that whether an object is a bitcode file or regular ELF object does not
+;; make any difference to which file is selected from an archive.
+
+; RUN: rm -rf %t.dir
+; RUN: split-file %s %t.dir
+; RUN: cd %t.dir
+
+; RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux ref.s -o ref.o
+; RUN: llvm-as a.ll -o a.bc
+; RUN: llvm-as b.ll -o b.bc
+; RUN: llc -filetype=obj a.ll -o a.o
+; RUN: llc -filetype=obj b.ll -o b.o
+
+; RUN: llvm-ar rc a.bc.b.bc.a a.bc b.bc
+; RUN: llvm-ar rc a.bc.b.o.a a.bc b.o
+; RUN: llvm-ar rc a.o.b.bc.a a.o b.bc
+; RUN: llvm-ar rc a.o.b.o.a a.o b.o
+; RUN: llvm-ar rc other.bc.a a.bc
+; RUN: llvm-ar rc other.o.a a.o
+
+; RUN: ld.lld -o /dev/null --trace ref.o a.bc.b.bc.a other.bc.a | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.bc.b.bc.a other.o.a  | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.bc.b.o.a  other.bc.a | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.bc.b.o.a  other.o.a  | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.o.b.bc.a  other.bc.a | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.o.b.bc.a  other.o.a  | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+; RUN: ld.lld -o /dev/null --trace ref.o a.o.b.o.a   other.bc.a | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+;; Not an LTO test case, but here for completeness.
+; RUN: ld.lld -o /dev/null --trace ref.o a.o.b.o.a   other.o.a  | \
+; RUN:   FileCheck %s --implicit-check-not={{.}}
+
+; CHECK:      ref.o
+; CHECK-NEXT: a.{{.*}}.b.{{.*}}.a(b.{{.*}})
+; CHECK-NEXT: a.{{.*}}.b.{{.*}}.a(a.{{.*}})
+
+;--- a.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"
+define void @bar() {
+  ret void
+}
+
+;--- b.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"
+define void @foo() {
+  call void @bar()
+  ret void
+}
+declare void @bar()
+
+;--- ref.s
+.global _start
+_start:
+  call foo

lld/test/ELF/lto/internalize-basic.ll

 ; REQUIRES: x86
 ; RUN: llvm-as %s -o %t.o
 ; RUN: ld.lld %t.o -o %t2 -save-temps
 ; RUN: llvm-dis < %t2.0.2.internalize.bc | FileCheck %s
 
 target triple = "x86_64-unknown-linux-gnu"
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 
 define void @_start() {
+  call void @bar()
+  ret void
+}
+
+define void @bar() {
   ret void
 }
 
 define hidden void @foo() {
   ret void
 }
 
 ; Check that _start is not internalized.
 ; CHECK: define dso_local void @_start()
 
-; Check that foo function is correctly internalized.
+; Check that the foo and bar functions are correctly internalized.
+; CHECK: define internal void @bar()
 ; CHECK: define internal void @foo()

lld/test/ELF/lto/undef-mixed2.test

+# REQUIRES: x86
+## Show that a symbol referenced from an object and defined in bitcode is
+## not internalized and is emitted in the output.
+
+# RUN: rm -rf %t.dir
+# RUN: split-file %s %t.dir
+# RUN: llvm-mc %t.dir/obj.s -o %t.o -filetype=obj -triple=x86_64-pc-linux
+# RUN: llvm-as %t.dir/bc.ll -o %t2.o
+# RUN: ld.lld %t2.o %t.o -o %t.so -shared
+# RUN: llvm-readobj --symbols %t.so | FileCheck %s
+
+# CHECK:      Name: foo
+# CHECK-NEXT: Value:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Binding: Local
+# CHECK-NEXT: Type: Function
+# CHECK-NEXT: Other [
+# CHECK-NEXT:   STV_HIDDEN
+# CHECK-NEXT: ]
+# CHECK-NEXT: Section: .text
+
+#--- obj.s
+  .globl  bar
+bar:
+  call foo
+
+#--- bc.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"
+
+define hidden void @foo() {
+  ret void
+}

lld/test/ELF/lto/wrap-2.ll

 ; REQUIRES: x86
-; LTO
-; RUN: llvm-as %s -o %t.o
-; RUN: llvm-as %S/Inputs/wrap-bar.ll -o %t1.o
-; RUN: ld.lld %t.o %t1.o -shared -o %t.so -wrap=bar
-; RUN: llvm-objdump -d %t.so | FileCheck %s
-; RUN: llvm-readobj --symbols %t.so | FileCheck -check-prefix=BIND %s
-
-; ThinLTO
-; RUN: opt -module-summary %s -o %t.o
-; RUN: opt -module-summary %S/Inputs/wrap-bar.ll -o %t1.o
-; RUN: ld.lld %t.o %t1.o -shared -o %t.so -wrap=bar
-; RUN: llvm-objdump -d %t.so | FileCheck %s
-; RUN: llvm-readobj --symbols %t.so | FileCheck -check-prefix=BIND %s
+;; This test verifies that --wrap works correctly for inter-module references to
+;; the wrapped symbol, when LTO or ThinLTO is involved. It checks for various
+;; combinations of bitcode and regular objects.
+
+;; LTO + LTO
+; RUN: llvm-as %s -o %t1.bc
+; RUN: llvm-as %S/Inputs/wrap-bar.ll -o %t2.bc
+; RUN: ld.lld %t1.bc %t2.bc -shared -o %t.bc-bc.so -wrap=bar
+; RUN: llvm-objdump -d %t.bc-bc.so | FileCheck %s --check-prefixes=CHECK,JMP
+; RUN: llvm-readobj --symbols %t.bc-bc.so | FileCheck --check-prefix=BIND %s
+
+;; LTO + Object
+; RUN: llc %S/Inputs/wrap-bar.ll -o %t2.o --filetype=obj
+; RUN: ld.lld %t1.bc %t2.o -shared -o %t.bc-o.so -wrap=bar
+; RUN: llvm-objdump -d %t.bc-o.so | FileCheck %s --check-prefixes=CHECK,JMP
+; RUN: llvm-readobj --symbols %t.bc-o.so | FileCheck --check-prefix=BIND %s
+
+;; Object + LTO
+; RUN: llc %s -o %t1.o --filetype=obj
+; RUN: ld.lld %t1.o %t2.bc -shared -o %t.o-bc.so -wrap=bar
+; RUN: llvm-objdump -d %t.o-bc.so | FileCheck %s --check-prefixes=CHECK,CALL
+; RUN: llvm-readobj --symbols %t.o-bc.so | FileCheck --check-prefix=BIND %s
+
+;; ThinLTO + ThinLTO
+; RUN: opt -module-summary %s -o %t1.thin
+; RUN: opt -module-summary %S/Inputs/wrap-bar.ll -o %t2.thin
+; RUN: ld.lld %t1.thin %t2.thin -shared -o %t.thin-thin.so -wrap=bar
+; RUN: llvm-objdump -d %t.thin-thin.so | FileCheck %s --check-prefixes=CHECK,JMP
+; RUN: llvm-readobj --symbols %t.thin-thin.so | FileCheck --check-prefix=BIND %s
+
+;; ThinLTO + Object
+; RUN: ld.lld %t1.thin %t2.o -shared -o %t.thin-o.so -wrap=bar
+; RUN: llvm-objdump -d %t.thin-o.so | FileCheck %s --check-prefixes=CHECK,JMP
+; RUN: llvm-readobj --symbols %t.thin-o.so | FileCheck --check-prefix=BIND %s
+
+;; Object + ThinLTO
+; RUN: ld.lld %t1.o %t2.thin -shared -o %t.o-thin.so -wrap=bar
+; RUN: llvm-objdump -d %t.o-thin.so | FileCheck %s --check-prefixes=CHECK,CALL
+; RUN: llvm-readobj --symbols %t.o-thin.so | FileCheck --check-prefix=BIND %s
 
-; Make sure that calls in foo() are not eliminated and that bar is
-; routed to __wrap_bar and __real_bar is routed to bar.
+;; Make sure that calls in foo() are not eliminated and that bar is
+;; routed to __wrap_bar and __real_bar is routed to bar.
 
 ; CHECK:      <foo>:
 ; CHECK-NEXT: pushq %rax
 ; CHECK-NEXT: callq{{.*}}<__wrap_bar>
-; CHECK-NEXT: popq  %rax
-; CHECK-NEXT: jmp{{.*}}<bar>
+; JMP-NEXT:   popq  %rax
+; JMP-NEXT:   jmp{{.*}}<bar>
+; CALL-NEXT:  callq{{.*}}<bar>
+; CALL-NEXT:  popq  %rax
 
-; Check that bar and __wrap_bar retain their original binding.
+;; Check that bar and __wrap_bar retain their original binding.
 ; BIND:      Name: bar
 ; BIND-NEXT: Value:
 ; BIND-NEXT: Size:
 ; BIND-NEXT: Binding: Local
 ; BIND:      Name: __wrap_bar
 ; BIND-NEXT: Value:
 ; BIND-NEXT: Size:
 ; BIND-NEXT: Binding: Local