Mahesha S via llvm-dev
2020-May-31 05:26 UTC
[llvm-dev] LLC crash while handling DEBUG info
Hi-
Here is the simple C++ function:
-----------
void foo() {
}
-----------
Let's say, above function is compiled to generate LLVM IR with -g flag
using the command line `clang++ -g -O0 -S -emit-llvm foo.cpp`, we get
below IR
-----------
; ModuleID = 'foo.cpp'
source_filename = "foo.cpp"
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 optnone uwtable
define dso_local void @_Z3foov() #0 !dbg !7 {
ret void, !dbg !10
}
attributes #0 = { noinline nounwind optnone uwtable
"correctly-rounded-divide-sqrt-fp-math"="false"
"disable-tail-calls"="false"
"frame-pointer"="all"
"less-precise-fpmad"="false"
"min-legal-vector-width"="0"
"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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87"
"unsafe-fp-math"="false"
"use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file:
!1, producer: "clang version 11.0.0
(https://github.com/llvm/llvm-project
9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false,
runtimeVersion: 0, emissionKind: FullDebug, enums: !2,
splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "foo.cpp", directory:
"/home/mahesha/ROCm/issues/hipclang/other/crash/foo")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project
9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"}
!7 = distinct !DISubprogram(name: "foo", linkageName:
"_Z3foov",
scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags:
DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0,
retainedNodes: !2)
!8 = !DISubroutineType(types: !9)
!9 = !{null}
!10 = !DILocation(line: 2, column: 1, scope: !7)
-----------
Now, let's say, in the above IR file, I intentionally make debug info
metadata, a kind of invalid, by removing the field 'unit` and by
changing the field `spFlags` from `DISPFlagDefinition` to
`DISPFlagOptimized` within metadata info !7 as shown below.
-----------
; ModuleID = 'foo.cpp'
source_filename = "foo.cpp"
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 optnone uwtable
define dso_local void @_Z3foov() #0 !dbg !7 {
ret void
}
attributes #0 = { noinline nounwind optnone uwtable
"correctly-rounded-divide-sqrt-fp-math"="false"
"disable-tail-calls"="false"
"frame-pointer"="all"
"less-precise-fpmad"="false"
"min-legal-vector-width"="0"
"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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87"
"unsafe-fp-math"="false"
"use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file:
!1, producer: "clang version 11.0.0
(https://github.com/llvm/llvm-project
9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false,
runtimeVersion: 0, emissionKind: FullDebug, enums: !2,
splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "foo.cpp", directory:
"/home/mahesha/ROCm/issues/hipclang/other/crash/foo")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project
9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"}
!7 = distinct !DISubprogram(name: "foo", linkageName:
"_Z3foov",
scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags:
DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
!8 = !DISubroutineType(types: !9)
!9 = !{null}
!10 = !DILocation(line: 2, column: 1, scope: !7)
-----------
Now, if I compile the above modified IR file using LLC, then LLC
crashes as below. The crash point is
https://github.com/llvm/llvm-project/blob/master/llvm/lib/CodeGen/LexicalScopes.cpp#L53.
Reason for crash is `NULL` pointer access. `DISubprogram::getUnit()`
returns `NULL` pointer since there is no `unit` field in the related
metadata info.
-----------
PLEASE submit a bug report to https://bugs.llvm.org/ and include the
crash backtrace.
Stack dump:
0. Program arguments: /opt/rocm/llvm/bin/llc foo.ll
1. Running pass 'Function Pass Manager' on module 'foo.ll'.
2. Running pass 'Debug Variable Analysis' on function
'@_Z3foov'
#0 0x0000556017a2aa8a llvm::sys::PrintStackTrace(llvm::raw_ostream&)
(/opt/rocm/llvm/bin/llc+0x1883a8a)
#1 0x0000556017a28854 llvm::sys::RunSignalHandlers()
(/opt/rocm/llvm/bin/llc+0x1881854)
#2 0x0000556017a289a3 SignalHandler(int) (/opt/rocm/llvm/bin/llc+0x18819a3)
#3 0x00007fdb38654890 __restore_rt
(/lib/x86_64-linux-gnu/libpthread.so.0+0x12890)
#4 0x0000556016f013ea
llvm::LexicalScopes::initialize(llvm::MachineFunction const&)
(/opt/rocm/llvm/bin/llc+0xd5a3ea)
#5 0x0000556016f224dd
llvm::LiveDebugVariables::runOnMachineFunction(llvm::MachineFunction&)
(/opt/rocm/llvm/bin/llc+0xd7b4dd)
#6 0x0000556016fcb2b0
llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
(/opt/rocm/llvm/bin/llc+0xe242b0)
#7 0x0000556017375e8f
llvm::FPPassManager::runOnFunction(llvm::Function&)
(/opt/rocm/llvm/bin/llc+0x11cee8f)
#8 0x0000556017376581 llvm::FPPassManager::runOnModule(llvm::Module&)
(/opt/rocm/llvm/bin/llc+0x11cf581)
#9 0x0000556017376981
llvm::legacy::PassManagerImpl::run(llvm::Module&)
(/opt/rocm/llvm/bin/llc+0x11cf981)
#10 0x000055601662496a main (/opt/rocm/llvm/bin/llc+0x47d96a)
#11 0x00007fdb372e8b97 __libc_start_main
/build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0
#12 0x000055601668f2ea _start (/opt/rocm/llvm/bin/llc+0x4e82ea)
-----------
QUESTION IS: Is this expected behavior? OR should LLC throw an error
and abort compilation? OR at the crash point, we are suppose to test
`nullity` of `DISubprogram::getUnit()` before accessing it?
--
Thanks,
Mahesha
David Blaikie via llvm-dev
2020-May-31 05:56 UTC
[llvm-dev] LLC crash while handling DEBUG info
In theory the LLVM IR verifier (llvm/lib/IR/Verifier.cpp) should catch this sort of thing. Maybe it isn't running in llc? It probably should be. It's also likely not exhaustive to completely arbitrary changes to the debug info IR - but could be improved if there are particular things folks come across/want to sure it up against. On Sat, May 30, 2020 at 10:27 PM Mahesha S via llvm-dev <llvm-dev at lists.llvm.org> wrote:> > Hi- > > Here is the simple C++ function: > > ----------- > void foo() { > } > ----------- > > Let's say, above function is compiled to generate LLVM IR with -g flag > using the command line `clang++ -g -O0 -S -emit-llvm foo.cpp`, we get > below IR > > ----------- > ; ModuleID = 'foo.cpp' > source_filename = "foo.cpp" > 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 optnone uwtable > define dso_local void @_Z3foov() #0 !dbg !7 { > ret void, !dbg !10 > } > > attributes #0 = { noinline nounwind optnone uwtable > "correctly-rounded-divide-sqrt-fp-math"="false" > "disable-tail-calls"="false" "frame-pointer"="all" > "less-precise-fpmad"="false" "min-legal-vector-width"="0" > "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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" > "unsafe-fp-math"="false" "use-soft-float"="false" } > > !llvm.dbg.cu = !{!0} > !llvm.module.flags = !{!3, !4, !5} > !llvm.ident = !{!6} > > !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: > !1, producer: "clang version 11.0.0 > (https://github.com/llvm/llvm-project > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false, > runtimeVersion: 0, emissionKind: FullDebug, enums: !2, > splitDebugInlining: false, nameTableKind: None) > !1 = !DIFile(filename: "foo.cpp", directory: > "/home/mahesha/ROCm/issues/hipclang/other/crash/foo") > !2 = !{} > !3 = !{i32 7, !"Dwarf Version", i32 4} > !4 = !{i32 2, !"Debug Info Version", i32 3} > !5 = !{i32 1, !"wchar_size", i32 4} > !6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"} > !7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", > scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: > DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, > retainedNodes: !2) > !8 = !DISubroutineType(types: !9) > !9 = !{null} > !10 = !DILocation(line: 2, column: 1, scope: !7) > ----------- > > Now, let's say, in the above IR file, I intentionally make debug info > metadata, a kind of invalid, by removing the field 'unit` and by > changing the field `spFlags` from `DISPFlagDefinition` to > `DISPFlagOptimized` within metadata info !7 as shown below. > > ----------- > ; ModuleID = 'foo.cpp' > source_filename = "foo.cpp" > 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 optnone uwtable > define dso_local void @_Z3foov() #0 !dbg !7 { > ret void > } > > attributes #0 = { noinline nounwind optnone uwtable > "correctly-rounded-divide-sqrt-fp-math"="false" > "disable-tail-calls"="false" "frame-pointer"="all" > "less-precise-fpmad"="false" "min-legal-vector-width"="0" > "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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" > "unsafe-fp-math"="false" "use-soft-float"="false" } > > !llvm.dbg.cu = !{!0} > !llvm.module.flags = !{!3, !4, !5} > !llvm.ident = !{!6} > > !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: > !1, producer: "clang version 11.0.0 > (https://github.com/llvm/llvm-project > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false, > runtimeVersion: 0, emissionKind: FullDebug, enums: !2, > splitDebugInlining: false, nameTableKind: None) > !1 = !DIFile(filename: "foo.cpp", directory: > "/home/mahesha/ROCm/issues/hipclang/other/crash/foo") > !2 = !{} > !3 = !{i32 7, !"Dwarf Version", i32 4} > !4 = !{i32 2, !"Debug Info Version", i32 3} > !5 = !{i32 1, !"wchar_size", i32 4} > !6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"} > !7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", > scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: > DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2) > !8 = !DISubroutineType(types: !9) > !9 = !{null} > !10 = !DILocation(line: 2, column: 1, scope: !7) > ----------- > > Now, if I compile the above modified IR file using LLC, then LLC > crashes as below. The crash point is > https://github.com/llvm/llvm-project/blob/master/llvm/lib/CodeGen/LexicalScopes.cpp#L53. > Reason for crash is `NULL` pointer access. `DISubprogram::getUnit()` > returns `NULL` pointer since there is no `unit` field in the related > metadata info. > > ----------- > PLEASE submit a bug report to https://bugs.llvm.org/ and include the > crash backtrace. > Stack dump: > 0. Program arguments: /opt/rocm/llvm/bin/llc foo.ll > 1. Running pass 'Function Pass Manager' on module 'foo.ll'. > 2. Running pass 'Debug Variable Analysis' on function '@_Z3foov' > #0 0x0000556017a2aa8a llvm::sys::PrintStackTrace(llvm::raw_ostream&) > (/opt/rocm/llvm/bin/llc+0x1883a8a) > #1 0x0000556017a28854 llvm::sys::RunSignalHandlers() > (/opt/rocm/llvm/bin/llc+0x1881854) > #2 0x0000556017a289a3 SignalHandler(int) (/opt/rocm/llvm/bin/llc+0x18819a3) > #3 0x00007fdb38654890 __restore_rt > (/lib/x86_64-linux-gnu/libpthread.so.0+0x12890) > #4 0x0000556016f013ea > llvm::LexicalScopes::initialize(llvm::MachineFunction const&) > (/opt/rocm/llvm/bin/llc+0xd5a3ea) > #5 0x0000556016f224dd > llvm::LiveDebugVariables::runOnMachineFunction(llvm::MachineFunction&) > (/opt/rocm/llvm/bin/llc+0xd7b4dd) > #6 0x0000556016fcb2b0 > llvm::MachineFunctionPass::runOnFunction(llvm::Function&) > (/opt/rocm/llvm/bin/llc+0xe242b0) > #7 0x0000556017375e8f > llvm::FPPassManager::runOnFunction(llvm::Function&) > (/opt/rocm/llvm/bin/llc+0x11cee8f) > #8 0x0000556017376581 llvm::FPPassManager::runOnModule(llvm::Module&) > (/opt/rocm/llvm/bin/llc+0x11cf581) > #9 0x0000556017376981 > llvm::legacy::PassManagerImpl::run(llvm::Module&) > (/opt/rocm/llvm/bin/llc+0x11cf981) > #10 0x000055601662496a main (/opt/rocm/llvm/bin/llc+0x47d96a) > #11 0x00007fdb372e8b97 __libc_start_main > /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0 > #12 0x000055601668f2ea _start (/opt/rocm/llvm/bin/llc+0x4e82ea) > ----------- > > QUESTION IS: Is this expected behavior? OR should LLC throw an error > and abort compilation? OR at the crash point, we are suppose to test > `nullity` of `DISubprogram::getUnit()` before accessing it? > > -- > Thanks, > Mahesha > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
Mahesha S via llvm-dev
2020-May-31 09:53 UTC
[llvm-dev] LLC crash while handling DEBUG info
Hi David If you look at line https://github.com/llvm/llvm-project/blob/master/llvm/lib/IR/Verifier.cpp#L1160 there is IR verification which asserts that only in case of `spFlags = DISPFlagDefinition`, the compilation unit (`unit` field) should be present. Otherwise, it should *not* be present. In the crash case, `spFlags = DISPFlagOptimized`. So, I guess, `unit` field should *not* be present, though I do not know the difference between ` DISPFlagDefinition` and ` DISPFlagOptimized`. if that is expected, then we may need to check `nullity` of `DISubprogram::getUnit()` before accessing it at https://github.com/llvm/llvm-project/blob/master/llvm/lib/CodeGen/LexicalScopes.cpp#L53 Thanks, Mahesha On Sun, May 31, 2020 at 11:26 AM David Blaikie <dblaikie at gmail.com> wrote:> In theory the LLVM IR verifier (llvm/lib/IR/Verifier.cpp) should catch > this sort of thing. Maybe it isn't running in llc? It probably should > be. It's also likely not exhaustive to completely arbitrary changes to > the debug info IR - but could be improved if there are particular > things folks come across/want to sure it up against. > > On Sat, May 30, 2020 at 10:27 PM Mahesha S via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > > > > Hi- > > > > Here is the simple C++ function: > > > > ----------- > > void foo() { > > } > > ----------- > > > > Let's say, above function is compiled to generate LLVM IR with -g flag > > using the command line `clang++ -g -O0 -S -emit-llvm foo.cpp`, we get > > below IR > > > > ----------- > > ; ModuleID = 'foo.cpp' > > source_filename = "foo.cpp" > > 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 optnone uwtable > > define dso_local void @_Z3foov() #0 !dbg !7 { > > ret void, !dbg !10 > > } > > > > attributes #0 = { noinline nounwind optnone uwtable > > "correctly-rounded-divide-sqrt-fp-math"="false" > > "disable-tail-calls"="false" "frame-pointer"="all" > > "less-precise-fpmad"="false" "min-legal-vector-width"="0" > > "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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" > > "unsafe-fp-math"="false" "use-soft-float"="false" } > > > > !llvm.dbg.cu = !{!0} > > !llvm.module.flags = !{!3, !4, !5} > > !llvm.ident = !{!6} > > > > !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: > > !1, producer: "clang version 11.0.0 > > (https://github.com/llvm/llvm-project > > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false, > > runtimeVersion: 0, emissionKind: FullDebug, enums: !2, > > splitDebugInlining: false, nameTableKind: None) > > !1 = !DIFile(filename: "foo.cpp", directory: > > "/home/mahesha/ROCm/issues/hipclang/other/crash/foo") > > !2 = !{} > > !3 = !{i32 7, !"Dwarf Version", i32 4} > > !4 = !{i32 2, !"Debug Info Version", i32 3} > > !5 = !{i32 1, !"wchar_size", i32 4} > > !6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project > > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"} > > !7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", > > scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: > > DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, > > retainedNodes: !2) > > !8 = !DISubroutineType(types: !9) > > !9 = !{null} > > !10 = !DILocation(line: 2, column: 1, scope: !7) > > ----------- > > > > Now, let's say, in the above IR file, I intentionally make debug info > > metadata, a kind of invalid, by removing the field 'unit` and by > > changing the field `spFlags` from `DISPFlagDefinition` to > > `DISPFlagOptimized` within metadata info !7 as shown below. > > > > ----------- > > ; ModuleID = 'foo.cpp' > > source_filename = "foo.cpp" > > 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 optnone uwtable > > define dso_local void @_Z3foov() #0 !dbg !7 { > > ret void > > } > > > > attributes #0 = { noinline nounwind optnone uwtable > > "correctly-rounded-divide-sqrt-fp-math"="false" > > "disable-tail-calls"="false" "frame-pointer"="all" > > "less-precise-fpmad"="false" "min-legal-vector-width"="0" > > "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"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" > > "unsafe-fp-math"="false" "use-soft-float"="false" } > > > > !llvm.dbg.cu = !{!0} > > !llvm.module.flags = !{!3, !4, !5} > > !llvm.ident = !{!6} > > > > !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: > > !1, producer: "clang version 11.0.0 > > (https://github.com/llvm/llvm-project > > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)", isOptimized: false, > > runtimeVersion: 0, emissionKind: FullDebug, enums: !2, > > splitDebugInlining: false, nameTableKind: None) > > !1 = !DIFile(filename: "foo.cpp", directory: > > "/home/mahesha/ROCm/issues/hipclang/other/crash/foo") > > !2 = !{} > > !3 = !{i32 7, !"Dwarf Version", i32 4} > > !4 = !{i32 2, !"Debug Info Version", i32 3} > > !5 = !{i32 1, !"wchar_size", i32 4} > > !6 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project > > 9e0b52e2e68412a9a2add18697f4246e5e5ee5e3)"} > > !7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", > > scope: !1, file: !1, line: 1, type: !8, scopeLine: 1, flags: > > DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2) > > !8 = !DISubroutineType(types: !9) > > !9 = !{null} > > !10 = !DILocation(line: 2, column: 1, scope: !7) > > ----------- > > > > Now, if I compile the above modified IR file using LLC, then LLC > > crashes as below. The crash point is > > > https://github.com/llvm/llvm-project/blob/master/llvm/lib/CodeGen/LexicalScopes.cpp#L53 > . > > Reason for crash is `NULL` pointer access. `DISubprogram::getUnit()` > > returns `NULL` pointer since there is no `unit` field in the related > > metadata info. > > > > ----------- > > PLEASE submit a bug report to https://bugs.llvm.org/ and include the > > crash backtrace. > > Stack dump: > > 0. Program arguments: /opt/rocm/llvm/bin/llc foo.ll > > 1. Running pass 'Function Pass Manager' on module 'foo.ll'. > > 2. Running pass 'Debug Variable Analysis' on function '@_Z3foov' > > #0 0x0000556017a2aa8a llvm::sys::PrintStackTrace(llvm::raw_ostream&) > > (/opt/rocm/llvm/bin/llc+0x1883a8a) > > #1 0x0000556017a28854 llvm::sys::RunSignalHandlers() > > (/opt/rocm/llvm/bin/llc+0x1881854) > > #2 0x0000556017a289a3 SignalHandler(int) > (/opt/rocm/llvm/bin/llc+0x18819a3) > > #3 0x00007fdb38654890 __restore_rt > > (/lib/x86_64-linux-gnu/libpthread.so.0+0x12890) > > #4 0x0000556016f013ea > > llvm::LexicalScopes::initialize(llvm::MachineFunction const&) > > (/opt/rocm/llvm/bin/llc+0xd5a3ea) > > #5 0x0000556016f224dd > > llvm::LiveDebugVariables::runOnMachineFunction(llvm::MachineFunction&) > > (/opt/rocm/llvm/bin/llc+0xd7b4dd) > > #6 0x0000556016fcb2b0 > > llvm::MachineFunctionPass::runOnFunction(llvm::Function&) > > (/opt/rocm/llvm/bin/llc+0xe242b0) > > #7 0x0000556017375e8f > > llvm::FPPassManager::runOnFunction(llvm::Function&) > > (/opt/rocm/llvm/bin/llc+0x11cee8f) > > #8 0x0000556017376581 llvm::FPPassManager::runOnModule(llvm::Module&) > > (/opt/rocm/llvm/bin/llc+0x11cf581) > > #9 0x0000556017376981 > > llvm::legacy::PassManagerImpl::run(llvm::Module&) > > (/opt/rocm/llvm/bin/llc+0x11cf981) > > #10 0x000055601662496a main (/opt/rocm/llvm/bin/llc+0x47d96a) > > #11 0x00007fdb372e8b97 __libc_start_main > > /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0 > > #12 0x000055601668f2ea _start (/opt/rocm/llvm/bin/llc+0x4e82ea) > > ----------- > > > > QUESTION IS: Is this expected behavior? OR should LLC throw an error > > and abort compilation? OR at the crash point, we are suppose to test > > `nullity` of `DISubprogram::getUnit()` before accessing it? > > > > -- > > Thanks, > > Mahesha > > _______________________________________________ > > LLVM Developers mailing list > > llvm-dev at lists.llvm.org > > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-- Thanks, Mahesha -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200531/a114065e/attachment-0001.html>
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