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llvm-project/llvm/test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll

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[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; Test that global metadata is placed in a separate section on Mach-O platforms,
; allowing dead stripping to be performed, and that the appropriate runtime
; routines are invoked.
[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] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.11.0"
@global = global [1 x i32] zeroinitializer, align 4
!llvm.asan.globals = !{!0}
!0 = !{[1 x i32]* @global, !1, !"global", i1 false, i1 false}
!1 = !{!"test-globals.c", i32 1, i32 5}
; Find the metadata for @global:
[asan] Don't overalign global metadata. Other than on COFF with incremental linking, global metadata should not need any extra alignment. Differential Revision: https://reviews.llvm.org/D28628 llvm-svn: 291859
2017-01-13 07:26:20 +08:00
; CHECK: [[METADATA:@.+]] = internal global {{.*}} @global {{.*}} section "__DATA,__asan_globals,regular"
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; Find the liveness binder for @global and its metadata:
[ASAN] Add the binder globals on Darwin to llvm.compiler.used to avoid LTO dead-stripping The binder is in a specific section that "reverse" the edges in a regular dead-stripping: the binder is live as long as a global it references is live. This is a big hammer that prevents LLVM from dead-stripping these, while still allowing linker dead-stripping (with special knowledge of the section). Differential Revision: https://reviews.llvm.org/D24673 llvm-svn: 282988
2016-10-01 08:05:34 +08:00
; CHECK: @__asan_binder_global = internal global {{.*}} @global {{.*}} [[METADATA]] {{.*}} section "__DATA,__asan_liveness,regular,live_support"
; The binder has to be inserted to llvm.compiler.used to avoid being stripped
; during LTO.
; CHECK: @llvm.compiler.used {{.*}} @__asan_binder_global {{.*}} section "llvm.metadata"
[asan] Refactor instrumentation of globals. llvm-svn: 291858
2017-01-13 07:03:03 +08:00
; Test that there is the flag global variable:
[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
; CHECK: @___asan_globals_registered = common hidden global i64 0
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
[asan] Fix testcase for r264645 llvm-svn: 264652
2016-03-29 04:42:56 +08:00
; Test that __asan_register_image_globals is invoked from the constructor:
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; CHECK-LABEL: define internal void @asan.module_ctor
; CHECK-NOT: ret
[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
; CHECK: call void @__asan_register_image_globals(i64 ptrtoint (i64* @___asan_globals_registered to i64))
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; CHECK: ret
[asan] Fix testcase for r264645 llvm-svn: 264652
2016-03-29 04:42:56 +08:00
; Test that __asan_unregister_image_globals is invoked from the destructor:
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; CHECK-LABEL: define internal void @asan.module_dtor
; CHECK-NOT: ret
[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
; CHECK: call void @__asan_unregister_image_globals(i64 ptrtoint (i64* @___asan_globals_registered to i64))
[asan] Support dead code stripping on Mach-O platforms On OS X El Capitan and iOS 9, the linker supports a new section attribute, live_support, which allows dead stripping to remove dead globals along with the ASAN metadata about them. With this change __asan_global structures are emitted in a new __DATA,__asan_globals section on Darwin. Additionally, there is a __DATA,__asan_liveness section with the live_support attribute. Each entry in this section is simply a tuple that binds together the liveness of a global variable and its ASAN metadata structure. Thus the metadata structure will be alive if and only if the global it references is also alive. Review: http://reviews.llvm.org/D16737 llvm-svn: 264645
2016-03-29 04:28:57 +08:00
; CHECK: ret