llvm dev - Mar 2017 - LLD/Mach-O - how to work around this bug?

I filed this bug today: https://bugs.llvm.org/show_bug.cgi?id=32376

I understand that the Mach-O linker is not under active development, but
there must be some way to work around this bug. Does anyone have a clue?

This trivial IR file gives "dyld: lazy symbol binding failed: bad lazy bind
info" at runtime when linked with:

 lld -flavor darwin -demangle -dynamic -arch x86_64 -macosx_version_min
10.10.0 -pie -o ./tmp_exe ./tmp_exe.o -lSystem

When linking with the system linker instead, with the same arguments, it
works fine. IR file:

target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-darwin-unknown"

@0 = internal unnamed_addr constant [9 x i8] c"0: %llu\0A\00", align 1

; Function Attrs: nounwind
define i32 @main(i32, i8** nocapture nonnull readnone) local_unnamed_addr
#0 {
Entry:
  %putchar = call i32 @putchar(i32 10)
  %2 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9
x i8]* @0, i64 0, i64 0), i64 0)
  ret i32 0
}

; Function Attrs: nounwind
declare i32 @printf(i8* nocapture readonly, ...) #0

declare i32 @putchar(i32) #0

attributes #0 = { nounwind }
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On Wed, Mar 22, 2017 at 9:59 AM, Andrew Kelley via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> I filed this bug today: https://bugs.llvm.org/show_bug.cgi?id=32376
>
> I understand that the Mach-O linker is not under active development, but
> there must be some way to work around this bug. Does anyone have a clue?
>
> This trivial IR file gives "dyld: lazy symbol binding failed: bad lazy
bind
> info" at runtime when linked with:
>
>  lld -flavor darwin -demangle -dynamic -arch x86_64 -macosx_version_min
> 10.10.0 -pie -o ./tmp_exe ./tmp_exe.o -lSystem
>
CC'ing the owners as they may have ideas. Please consider that lld
MachO hasn't been touched in 6-9 months for anything real, at least.
Even if you work around this bug, chances are you'll find many others.
In other words, don't expect to be on par with ld64.

-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare

Hello Andrew,

If you want to try to figure out what is up with the lazy binding info you might
try running top of tree llvm-objdump with -lazy-bind to see what error it gives
you (that is with my change from Monday with r298292).  The other thing you can
do on a MacOS machine is:

xcrun dyldinfo -opcodes ./tmp_exe

to show the bind opcodes that the error message from llvm-objdump should be
referring to. That may give you a start as to what is wrong if you want to try
to fix the problem in lld.

My thoughts,
Kev
> On Mar 22, 2017, at 12:05 PM, Davide Italiano via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> On Wed, Mar 22, 2017 at 9:59 AM, Andrew Kelley via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>> I filed this bug today: https://bugs.llvm.org/show_bug.cgi?id=32376
>> 
>> I understand that the Mach-O linker is not under active development,
but
>> there must be some way to work around this bug. Does anyone have a
clue?
>> 
>> This trivial IR file gives "dyld: lazy symbol binding failed: bad
lazy bind
>> info" at runtime when linked with:
>> 
>> lld -flavor darwin -demangle -dynamic -arch x86_64 -macosx_version_min
>> 10.10.0 -pie -o ./tmp_exe ./tmp_exe.o -lSystem
>> 
> 
> CC'ing the owners as they may have ideas. Please consider that lld
> MachO hasn't been touched in 6-9 months for anything real, at least.
> Even if you work around this bug, chances are you'll find many others.
> In other words, don't expect to be on par with ld64.
> 
> -- 
> Davide
> 
> "There are no solved problems; there are only problems that are more
> or less solved" -- Henri Poincare
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