maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/Instrumentation/AddressSanitizer/global_metadata_windows.ll

39 lines
2.2 KiB
LLVM
Raw Normal View History

[asan] Make ASan compatible with linker dead stripping on Windows Summary: This is similar to what was done for Darwin in rL264645 / http://reviews.llvm.org/D16737, but it uses COFF COMDATs to achive the same result instead of relying on new custom linker features. As on MachO, this creates one metadata global per instrumented global. The metadata global is placed in the custom .ASAN$GL section, which the ASan runtime will iterate over during initialization. There are no other references to the metadata, so normal linker dead stripping would discard it. However, the metadata is put in a COMDAT group with the instrumented global, so that it will be discarded if and only if the instrumented global is discarded. I didn't update the ASan ABI version check since this doesn't affect non-Windows platforms, and the WinASan ABI isn't really stable yet. Implementing this for ELF will require extending LLVM IR and MC a bit so that we can use non-COMDAT section groups. Reviewers: pcc, kcc, mehdi_amini, kubabrecka Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26770 llvm-svn: 287576
2016-11-22 04:40:37 +08:00
; Test that global metadata is placed in a separate section on Windows, and that
; it is in the same comdat group as the instrumented global. This ensures that
; linker dead stripping (/OPT:REF) works as intended.
; FIXME: Later we can use this to instrument linkonce odr string literals.
[asan] Fix dead stripping of globals on Linux. Use a combination of !associated, comdat, @llvm.compiler.used and custom sections to allow dead stripping of globals and their asan metadata. Sometimes. Currently this works on LLD, which supports SHF_LINK_ORDER with sh_link pointing to the associated section. This also works on BFD, which seems to treat comdats as all-or-nothing with respect to linker GC. There is a weird quirk where the "first" global in each link is never GC-ed because of the section symbols. At this moment it does not work on Gold (as in the globals are never stripped). This is a second re-land of r298158. This time, this feature is limited to -fdata-sections builds. llvm-svn: 301587
2017-04-28 04:27:27 +08:00
; RUN: opt < %s -asan -asan-module -asan-globals-live-support=1 -S | FileCheck %s
[asan] Make ASan compatible with linker dead stripping on Windows Summary: This is similar to what was done for Darwin in rL264645 / http://reviews.llvm.org/D16737, but it uses COFF COMDATs to achive the same result instead of relying on new custom linker features. As on MachO, this creates one metadata global per instrumented global. The metadata global is placed in the custom .ASAN$GL section, which the ASan runtime will iterate over during initialization. There are no other references to the metadata, so normal linker dead stripping would discard it. However, the metadata is put in a COMDAT group with the instrumented global, so that it will be discarded if and only if the instrumented global is discarded. I didn't update the ASan ABI version check since this doesn't affect non-Windows platforms, and the WinASan ABI isn't really stable yet. Implementing this for ELF will require extending LLVM IR and MC a bit so that we can use non-COMDAT section groups. Reviewers: pcc, kcc, mehdi_amini, kubabrecka Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26770 llvm-svn: 287576
2016-11-22 04:40:37 +08:00
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc19.0.24215"
$mystr = comdat any
; CHECK: $dead_global = comdat noduplicates
; CHECK: @dead_global = local_unnamed_addr global { i32, [60 x i8] } { i32 42, [60 x i8] zeroinitializer }, comdat, align 32
[asan] Give global metadata private linkage. Internal linkage preserves names like "__asan_global_foo" which may account to 2% of unstripped binary size. llvm-svn: 299995
2017-04-12 06:28:13 +08:00
; CHECK: @__asan_global_dead_global = private global { {{.*}} }, section ".ASAN$GL", comdat($dead_global), align 64
[asan] Make ASan compatible with linker dead stripping on Windows Summary: This is similar to what was done for Darwin in rL264645 / http://reviews.llvm.org/D16737, but it uses COFF COMDATs to achive the same result instead of relying on new custom linker features. As on MachO, this creates one metadata global per instrumented global. The metadata global is placed in the custom .ASAN$GL section, which the ASan runtime will iterate over during initialization. There are no other references to the metadata, so normal linker dead stripping would discard it. However, the metadata is put in a COMDAT group with the instrumented global, so that it will be discarded if and only if the instrumented global is discarded. I didn't update the ASan ABI version check since this doesn't affect non-Windows platforms, and the WinASan ABI isn't really stable yet. Implementing this for ELF will require extending LLVM IR and MC a bit so that we can use non-COMDAT section groups. Reviewers: pcc, kcc, mehdi_amini, kubabrecka Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26770 llvm-svn: 287576
2016-11-22 04:40:37 +08:00
@dead_global = local_unnamed_addr global i32 42, align 4
@mystr = linkonce_odr unnamed_addr constant [5 x i8] c"main\00", comdat, align 1
; Function Attrs: nounwind uwtable
define i32 @main() local_unnamed_addr #0 {
entry:
%call = tail call i32 @puts(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @mystr, i64 0, i64 0))
ret i32 0
}
; Function Attrs: nounwind
declare i32 @puts(i8* nocapture readonly) local_unnamed_addr #1
attributes #0 = { nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.module.flags = !{!0}
!llvm.ident = !{!1}
!0 = !{i32 1, !"PIC Level", i32 2}
!1 = !{!"clang version 4.0.0 "}